Sintering system and sintered articles

Abstract

To provide thin, wide, and / or long sintered articles by a system such as in a roll to roll process.SOLUTION: A tape separation system includes a source of tape material comprising a green tape and a carrier web supporting the green tape. The green tape comprises grains of inorganic material in a binder. The tape separation system also includes a peeler for directing the carrier web in a rewind direction and directing the green tape in a downstream processing direction different from the rewind direction, and a vacuum drum positioned and configured to receive the tape material from the source and convey the tape material to the peeler. The vacuum drum comprises holes for applying suction to the carrier web to facilitate applying tension to the carrier web. The tension per cross sectional area of the carrier web is greater than tension in the green tape as the tape material is conveyed from the vacuum drum to the peeler, thereby mitigating deformation of the green tape during separation of the green tape from the carrier web.SELECTED DRAWING: Figure 3

Description

Priority

[0001] This application is a continuation of U.S. patent application Ser. No. 62 / 437,157, filed December 21, 2016; U.S. patent application Ser. No. 62 / 439,613, filed December 28, 2016; U.S. patent application Ser. No. 62 / 470,550, filed March 13, 2017; U.S. patent application Ser. No. 62 / 439,609, filed December 28, 2016; U.S. patent application Ser. No. 62 / 526,806, filed June 29, 2017; U.S. patent application Ser. No. 62 / 439,598, filed December 28, 2016; U.S. patent application Ser. No. 62 / 483,726, filed April 10, 2017; This is a divisional application of Patent Application No. 2023-216668 (filing date: December 22, 2023), which is a divisional application of Patent Application No. 2021-197031 (filing date: December 3, 2021), which is a divisional application of Patent Application No. 2019-533152 (filing date: December 19, 2017), which is an international application filed on June 24, 2019, claiming the benefit of priority under Section 119 of the U.S. Patent Act of U.S. Patent Application No. 62 / 484,106, filed on April 11, 2017, and U.S. Patent Application No. 62 / 556,712, filed on September 11, 2017. [Technical Field]

[0002] The present disclosure relates generally to processes for sintering, e.g., sintering green tapes containing polycrystalline ceramic grains or other inorganic particles bound in a binder; and continuous and discontinuous sintered articles, such as ceramic sheets, tapes, or ceramic strips, produced from the processes. The disclosure relates to articles, such as thin sheets, tapes, ribbons, or strips of ceramic or other inorganic materials, which have many potential uses, for example: acting as waveguides if the ceramic is optically transparent; acting as substrates that can be coated or laminated and incorporated into batteries and other components; or used as or bonded to substrates, such as to act as dielectrics in electronic packages (e.g., LED packages), or for other uses. Various material properties, particularly of ceramic materials, such as high resistivity, low reactivity, and low coefficient of thermal expansion, make the articles particularly useful in a wide range of applications. Summary of the Invention

[0003] Some aspects of the present disclosure relate to a tape separation system for preparing a sintered product. The tape separation system includes a source of tape material, the source including a substrate tape and a carrier web supporting the substrate tape. The substrate tape includes particles of an inorganic material in a binder. The tape separation system further includes: a stripper for orienting the carrier web in an unwinding direction and for orienting the substrate tape in a downstream process direction different from the unwinding direction; and a vacuum drum positioned and configured to receive the tape material from the source and transport the tape material to the stripper. The vacuum drum includes holes for applying suction to the carrier web to facilitate tensioning the carrier web, and the tension of the carrier web, as a force per cross-sectional area, is higher than the tension of the substrate tape as the tape material is transported from the vacuum drum to the stripper, thereby reducing deformation of the substrate tape during separation from the carrier web.

[0004] Another aspect of the present disclosure relates to a system for processing a tape in preparation for sintering, the system comprising: a tape having a green portion of the tape, the green portion having grains of inorganic material in an organic binder; and a binder burnout station having an active heater through which the tape advances, whereby the binder burnout station receives the green portion of the tape and carbonizes or burns the organic binder as the green portion of the tape contacts heat from the heater, thereby forming a second portion of the tape ready for sintering of the inorganic material of the tape. In some embodiments, at a given moment, the tape simultaneously extends toward, through, and from the binder burnout station, whereby at said moment, the tape includes the green portion continuously connected to the second portion, e.g., where the binder burnout station carbonizes or burns off at least most of the organic binder, by weight, from the green portion of the tape without substantially sintering the grains of the inorganic material. In some embodiments, the system for processing the tape in preparation for sintering further includes an ultra-low tension dancer, which includes a lightweight, low inertia roller for reorienting the tape without applying significant tension to the tape, whereby tension in the second portion of the tape is reduced to a value less than 1 mm 2 in cross section. 2 The binder burnout station heats the tape to a temperature above the temperature at which the organic binder ignites without the gas being blown and / or drawn onto the tape, thereby charring or burning the organic binder but not igniting the tape.

[0005] A further aspect of the present disclosure relates to a manufacturing line including the system for processing tape, wherein the binder burnout station is a first station, and the manufacturing line further includes a second station spaced from the first station. The second station at least partially sinters the inorganic material of the second portion of the tape to form a third portion of the tape, wherein at a certain moment, the tape includes a green portion continuously connected to the third portion via the second portion. For example, in some such embodiments, the third portion of the tape is significantly more flexible than the second portion, such that the minimum bend radius without breakage of the third portion is less than half that of the second portion, and the green portion is significantly more flexible than the second portion, such that the minimum bend radius without breakage of the green portion is less than half that of the second portion. The manufacturing line may further include the tape separation system described above.

[0006] Some aspects of the present disclosure relate to a sintering system including a tape material containing particles of inorganic material and a sintering station. The sintering station includes an inlet, an outlet, and a channel extending between the inlet and the outlet. At a given moment, the tape material extends into the inlet of the sintering station, through the channel, and out of the outlet. Heat in the channel sinters the inorganic material, causing the inorganic material to have a first porosity at the inlet and a second porosity at the outlet that is less than the first porosity. Furthermore, a positive tension is applied to the tape material as it passes through the channel of the sintering station, thereby reducing sintering stress. In some embodiments, the tape material moves through the sintering station at a rate of at least 1 inch (2.54 cm) per minute. In some embodiments, the channel of the sintering station is heated by at least two independently controlled heating elements that generate a temperature profile such that the temperature of the channel increases along the length of the channel in a direction from the entrance to the exit of the sintering station, and the sintering temperature within the channel is greater than 800° C. In some embodiments, the sintering system further includes a curved surface disposed along the channel of the sintering station, wherein the tape material bends about the curved surface, relative to a width axis of the tape material, as the tape material moves through the sintering station, thereby affecting the shape of the tape material.In some embodiments, the outlet and the inlet of the sintering station lie in a substantially horizontal plane, such that an angle defined between the outlet and the inlet of the sintering station and the horizontal is less than 10°, thereby at least partially controlling gas flow through the channel; for example, in some such embodiments, the sintering station further comprises an upward-facing channel surface defining a lower surface of the channel and a downward-facing channel surface defining an upper surface of the channel, wherein the downward-facing channel surface is positioned near an upper surface of the tape material, such that a gap between the upper surface of the tape material and the downward-facing channel surface is less than 0.5 inches (1.27 cm), thereby at least partially controlling gas flow through the channel. The tape material may be particularly wide, long, and thin, having a width greater than 5 millimeters, a length greater than 30 centimeters, and a thickness between 3 micrometers and 1 millimeter, and the inorganic material of the tape may be at least one of a polycrystalline ceramic material and a synthetic mineral.

[0007] Another aspect of the present disclosure relates to a process for manufacturing a ceramic tape, the process comprising sintering a tape comprising a polycrystalline ceramic by exposing particles of the polycrystalline ceramic to a heat source to induce sintering between the particles until the polycrystalline ceramic has a porosity of less than 20% by volume. The tape is particularly thin, having a thickness of less than 500 μm, which promotes rapid sintering by heat penetration. Furthermore, the tape is at least 5 mm wide and at least 300 cm long. In some embodiments, the process further comprises applying a positive longitudinal tension to the tape during the sintering. In some such embodiments, the process further comprises moving the tape toward and then away from the heat source during the sintering. In some embodiments, the amount of time for the sintering step is particularly short, less than two hours total, which helps maintain a small grain size in the ceramic tape; for example, in some such embodiments, the total time for the sintering step is less than one hour, the density of the polycrystalline ceramic after the sintering step is greater than 95% density by volume, and / or the tape comprises closed porosity after the sintering step. In some embodiments, the tape includes a volatile component that vaporizes during the sintering step, the volatile component is inorganic, and the tape includes at least 1% more of the volatile component by volume before the sintering step than after the sintering step.

[0008] Yet another aspect of the present disclosure relates to a tape comprising a body including grains of an inorganic material sintered to one another. The body extends between first and second major surfaces, and the body has a thickness defined as the distance between the first and second major surfaces, a width defined as a first dimension of the first major surface perpendicular to the thickness, and a length defined as a second dimension of the first major surface perpendicular to both the thickness and the width. The tape is long, having a length of about 300 cm or more. The tape is thin, having a thickness of about 3 μm to about 1 mm. The tape is particularly wide, having a width of about 5 mm or more. According to an exemplary embodiment, the geometric consistency of the tape is as follows: the difference in width of the tape measured at multiple locations spaced 1 m apart along its length is less than 100 μm; and the difference in thickness of the tape measured at multiple locations spaced 1 m apart along its width center is less than 10 μm. In some embodiments, the tape is flat or flattenable, such that a 10 cm length of the tape pressed between parallel flat surfaces flattens to within 0.05 mm of contact with the parallel flat surfaces without breaking; for example, in some such embodiments, when flattened to within 0.05 mm of contact with the parallel flat surfaces, the tape exhibits a maximum in-plane stress of 1% or less of its Young's modulus. In some embodiments, the first and second major surfaces of the tape have a grain profile, wherein the grains are ceramic, and wherein at least some individual grains of the ceramic are adjacent to one another with little or no intervening amorphous material, such that the thickness of amorphous material between two adjacent grains is less than 5 nm. In some embodiments, the body has a porosity of less than 10% by volume, and / or the body has closed pores. In some embodiments, the grains comprise lithium, and the body has a porosity of 5×10 -5The tape has an ionic conductivity of greater than 100 S / cm. In some embodiments, the body has a particularly fine grain size of 5 μm or less. In some embodiments, the tape further comprises a conductive metal coupled to the first major surface of the body, and in some such embodiments, the body comprises a repeating pattern of vias, and the conductive metal is arranged in a repeating pattern. In some embodiments, the first major surface and the second major surface have a grain profile, and the tape further comprises a coating overlying the grain profile of the first major surface, an outwardly facing surface of the coating having a lower roughness than the grain profile of the first surface, and wherein the conductive metal coupled to the first major surface is coupled via bonds to the outwardly facing surface of the coating. In some embodiments, the inorganic material has a viscosity of 12.5 poise at temperatures greater than 900° C.

[0009] A further aspect of the present disclosure relates to a roll of tape of any one of the above-described embodiments, wherein the tape is wrapped around and overlapping itself and bent to a radius of less than 30 cm.

[0010] Yet another aspect of the present disclosure relates to a plurality of sheets cut from the tape of any one of the above-described embodiments.

[0011] Some aspects of the present disclosure relate to a tape comprising a body including ceramic grains sintered to one another, the body extending between first and second major surfaces, wherein the body has a thickness defined as the distance between the first and second major surfaces, a width defined as a first dimension of the first major surface perpendicular to the thickness, and a length defined as a second dimension of the first major surface perpendicular to both the thickness and the width; wherein the tape is thin, having a thickness of about 3 μm to about 1 mm; and wherein the first and second major surfaces of the tape have a grain profile, wherein at least some individual grains of the ceramic are adjacent to one another with little or no intervening amorphous material, such that the thickness of the amorphous material between two adjacent grains is less than 5 nm.

[0012] Some aspects of the present disclosure relate to a tape comprising a body including ceramic grains sintered to one another, the body extending between first and second major surfaces, wherein the body has a thickness defined as the distance between the first and second major surfaces, a width defined as a first dimension of the first major surface perpendicular to the thickness, and a length defined as a second dimension of the first major surface perpendicular to both the thickness and the width; the tape is thin, having a thickness of about 3 μm to about 1 mm; the first and second major surfaces of the tape have a grain profile; wherein the grains comprise lithium and the body has a grain size of about 5×10 -5 It has an ionic conductivity of over 100 S / cm.

[0013] Additional features and advantages are set forth in the detailed description that follows, and in part will be readily apparent to those skilled in the art from the detailed description, or may be learned by practicing the embodiments as set forth in the description and claims of this application, and the accompanying drawings.

[0014] It is to be understood that both the foregoing Summary and the following Detailed Description are merely exemplary and are intended to provide an overview or framework for understanding the nature and characteristics of the claims.

[0015] The accompanying drawings are included to provide a further understanding, and are incorporated in and constitute a part of this specification. The drawings illustrate one or more embodiments, and together with the description, serve to explain the principles and operation of various embodiments. [Brief explanation of the drawings]

[0016] [Figure 1] 10. Examples of strained sintered ceramic tape materials formed without the use of techniques disclosed herein, such as controlled green ribbon tensioning and other techniques described herein. [Figure 2] Example of distorted sintered ceramic tape material produced using a temperature profile and tape speed that causes non-uniform sintering [Figure 3] Roll-to-roll system for producing sintered articles, according to certain exemplary embodiments [Figure 4] 4 is a close-up view of an embodiment of the separation system shown in FIG. 3, according to an example embodiment. [Figure 5] 1 is a side view of a continuous tape material according to an example embodiment; [Figure 6] 1 is a perspective view of a vacuum drum according to an example embodiment; [Figure 7] 7 is a close-up view of the vacuum drum shown in FIG. 6 according to an example embodiment. [Figure 8] 5 is a close-up view of the stripper shown in FIG. 4 according to an exemplary embodiment. [Figure 9] FIG. 1 is a conceptual side view of a station of a manufacturing line for preparing a green tape for sintering, according to an example embodiment; [Figure 10] FIG. 10 is a front perspective view of the station of FIG. 9 in accordance with an exemplary embodiment. [Figure 11]1 is a block diagram of a method for processing a substrate tape to at least partially prepare the substrate tape for sintering, according to an exemplary embodiment; [Figure 12] 4 is a detailed view of the debinder station and the sintering station of the system of FIG. 3, according to an example embodiment. [Figure 13] 13 is a detailed view of the tape material within the channel of the sintering furnace of FIG. 12, according to an example embodiment. [Figure 14] Sintered tape material exiting a sintering furnace according to an exemplary embodiment. [Figure 15] 13 is a diagram of the sintering station of FIG. 12 showing a heating system, according to an example embodiment. [Figure 16] 10 is a graph of predicted thermal profiles and modeled sintering shrinkage versus distance for different tape transport speeds according to an example embodiment; [Figure 17] Expected sintering temperature profile projected along the channel of a sintering furnace, according to an exemplary embodiment. [Figure 18] In-line multi-furnace sintering station according to certain exemplary embodiments [Figure 19] Expected temperature profiles for the two sintering furnaces of FIG. 18, according to an exemplary embodiment. [Figure 20] Sintering system with two parallel production systems, according to an exemplary embodiment [Figure 21] Graph of sintering shrinkage of zirconia tape at various temperatures and time at temperature, including curves fitted to the data for each temperature. [Figure 22] Graph of curve fitting of mathematical function of sintering shrinkage of zirconia tape at various temperatures and time at various temperatures. [Figure 23] 1 is a modeled graph of peak stress at the centerline of a zirconia tape during sintering as a function of number of heating zones, number of passes, and tape transport speed as a function of tape width. [Figure 24]1 is a modeled graph of peak stress at the edge of a zirconia tape during sintering as a function of the number of heating zones, the number of passes, and the tape transport speed as a function of the tape width. [Figure 25] Modeled graph of zirconia tape shrinkage during sintering using two passes through a single hot zone for two tape transport speeds. [Figure 26] Modeled graph of stress in zirconia tape during sintering using two passes through a single hot zone for two tape transport speeds. [Figure 27] Modeled graph of zirconia tape shrinkage during sintering using two passes through ten high temperature zones for two tape transport speeds. [Figure 28] Modeled graph of stress (MPa) in zirconia tape during sintering using two passes through ten hot zones for two tape transport speeds and various tape widths. [Figure 29] 1 is a perspective view of a portion of a sintered article according to an exemplary embodiment; [Figure 30A] Digital image of the unpolished surface of the sintered article [Figure 30B] A conceptual side profile of the sintered article of FIG. 30A. [Figure 31A] Digital image of the polished surface of the sintered article [Figure 31B] A conceptual side profile of the sintered article of FIG. 31A. [Figure 32] 1 is a side view along the width of a sintered article according to one or more embodiments. [Figure 33] Diagram to explain the equation for thin plate bending stress [Figure 34A] FIG. 1 is a side perspective view of a rolled sintered article according to an exemplary embodiment; [Figure 34B] FIG. 34B is a cross-sectional view of the rolled sintered article of FIG. 34A according to an exemplary embodiment. [Figure 35] 1 is a height profile of the sintered article of Example 5 before planarization, showing the height measured above the planarization plane. [Figure 36] 1. Height profile of the sintered article of Example 6 before planarization, showing the height measured above the planarization plane. [Figure 37] 1 is a height profile of the sintered article of Comparative Example 7 before planarization, showing the height measured above the planarization plane. [Figure 38] 1. Height profile of the sintered article of Comparative Example 8 before planarization, showing the height measured above the planarization plane. [Figure 39] Plots of maximum height above the planarizing plane for Examples 5-6 and Comparative Examples 7-8 [Figure 40] Plot of the force required to flatten the sintered articles of Examples 5-6 and Comparative Examples 7-8 [Figure 41] Plot of the pressure required to flatten the sintered articles of Examples 5-6 and Comparative Examples 7-8 [Figure 42] Plot of maximum in-plane stress after flattening for sintered articles of Examples 5-6 and Comparative Examples 7-8. [Figure 43A] 10 is a deformation plot showing the measured stress on the bottom surface of the sintered article of Example 5 after flattening. [Figure 43B] 10 is a deformation plot showing the measured stress on the top surface of the sintered article of Example 5 after flattening. [Figure 44A] 10 is a deformation plot showing the measured stress on the bottom surface of the sintered article of Example 6 after flattening. [Figure 44B] 10 is a deformation plot showing the measured stress on the top surface of the sintered article of Example 6 after flattening. [Figure 45A] 1 is a deformation plot showing the measured stress on the bottom surface of the sintered article of Comparative Example 7 after flattening. [Figure 45B] 1 is a deformation plot showing the measured stress on the top surface of the sintered article of Comparative Example 7 after flattening. [Figure 46A] 1 is a deformation plot showing the measured stress on the bottom surface of the sintered article of Comparative Example 8 after flattening. [Figure 46B] 1 is a deformation plot showing the measured stress on the top surface of the sintered article of Comparative Example 8 after flattening. [Figure 47] 1 is a cross-sectional view of a segment of a package containing sintered articles, according to an exemplary embodiment; [Figure 48] 1 is a longitudinal cross-sectional view of a segment of a package containing sintered articles according to an exemplary embodiment; [Figure 49] 1 is another cross-sectional view of a segment of a package including sintered articles according to an exemplary embodiment; [Figure 50] Exemplary Method for Producing a Package Including a Sintered Article According to Certain Exemplary Embodiments [Figure 51] Another exemplary method for making a package including a sintered article according to an exemplary embodiment [Figure 52] 1 is an exemplary cross-sectional view of a segment of a package including a sintered article and a "flip-chip" configuration, according to an exemplary embodiment; [Figure 53] FIG. 10 is another exemplary cross-sectional view of a segment of a package including a sintered article and a “flip-chip” configuration, according to an exemplary embodiment. [Figure 54] FIG. 10 is yet another exemplary cross-sectional view of a segment of a package including a sintered article and a “flip-chip” configuration, according to an exemplary embodiment. [Figure 55] 1 is another cross-sectional view of a segment of a package including sintered articles according to an exemplary embodiment; [Figure 56] A roll-to-roll system and associated process for producing a sintered article including a length of threading material, according to certain exemplary embodiments. [Figure 57] 57 is a detailed view showing the bond between a length of threading material and tape material in the system of FIG. 56, according to an example embodiment. [Figure 58] A roll-to-roll system including a sintering station configured to form a longitudinal curvature in a continuous length of tape material, according to an exemplary embodiment. [Figure 59]FIG. 1 is a detailed view of a sintering station including an insert that defines a curved lower surface of a sintering channel, according to an example embodiment. [Figure 60] FIG. 1 is a side view of a channel of a sintering station having opposing curved upper and lower surfaces defining the sintering channel, according to an example embodiment. [Figure 61] 1 is a side schematic view of a sintering station with varying radii of curvature along the sintering channel, according to an example embodiment; [Figure 62] Gas bearing having a curved upper surface defining the curved surface of the sintering channel, according to an exemplary embodiment [Figure 63] Roller arrangement for forming a longitudinal curvature in a continuous length of tape during sintering, according to an exemplary embodiment [Figure 64] A configuration including multiple rollers for forming multiple longitudinal curvatures in a continuous length of tape during sintering, according to an exemplary embodiment. [Figure 65] Free Loop Configuration for Forming Longitudinal Curvature in a Continuous Length of Tape During Sintering, According to Certain Exemplary Embodiments [Figure 66] Digital image of sintered tape demonstrating the flattening that occurs when the tape is bent during sintering. [Figure 67A] Digital image of a roll of sintered ceramic tape, according to an example embodiment. [Figure 67B] Digital image of a roll of sintered ceramic tape, according to an example embodiment. [Figure 68] Digital image of a roll of sintered ceramic tape according to another embodiment [Figure 69] Digital image of a roll of sintered ceramic tape according to yet another embodiment [Figure 70] 1 is a graph of sintering times for conventional batch firing and the disclosed technology, according to certain example embodiments; [Figure 71A] 1 is a top view of a surface of a sintered article according to an exemplary embodiment; [Figure 71B]1 is a top view of a surface of a sintered article according to an exemplary embodiment; [Figure 72A] 1 is a side perspective view of a surface of a sintered article according to an exemplary embodiment; [Figure 72B] 1 is a side perspective view of a surface of a sintered article according to an exemplary embodiment; [Figure 73A] 1 is a photomicrograph of a grain boundary of a sintered article according to an exemplary embodiment; [Figure 73B] 1 is a photomicrograph of a grain boundary of a sintered article according to an exemplary embodiment; [Figure 73C] 1 is a photomicrograph of a grain boundary of a sintered article according to an exemplary embodiment; [Figure 74] 1 is a photomicrograph of a grain boundary of a sintered article according to another exemplary embodiment; [Figure 75] 1 is a photomicrograph of a grain boundary of a sintered article according to another exemplary embodiment; [Figure 76] 1 is a top view of a surface of a sintered article according to an exemplary embodiment; [Figure 77] 1 is a top view of a surface of a sintered article according to an exemplary embodiment; [Figure 78] Digital image of a tape of a sintered article according to an exemplary embodiment. [Figure 79A] 1 is a side view of a sintered article according to an exemplary embodiment; [Figure 79B] 1 is a side view of a sintered article according to an exemplary embodiment; [Figure 80] 1 is a side view of a sintered article according to an exemplary embodiment; [Figure 81] FIG. 10 is a side view of a sintered article according to another exemplary embodiment, in which the sintered material appears amorphous. [Figure 82] Multiple composition graph [Figure 83] 1 is a side perspective view of a surface of a sintered article according to an exemplary embodiment; [Figure 84] 1 is a side perspective view of a surface of a sintered article according to an exemplary embodiment; [Figure 85A] 1 is a side perspective view of a surface of an unsintered green material according to an exemplary embodiment; [Figure 85B] 1 is a side perspective view of a surface of an unsintered green material according to an exemplary embodiment; [Figure 86A] 1 is a side perspective view of a sintered material according to an exemplary embodiment; [Figure 86B] 1 is a side perspective view of a sintered material according to an exemplary embodiment; [Figure 87] Viscosity vs. temperature graphs for various materials [Figure 88A] 1 is a graph of a temperature profile through a sintering furnace according to an example embodiment; [Figure 88B] Schematic diagram of the sintering furnace of FIG. [Figure 89] Schematic diagram of a sintering furnace according to another exemplary embodiment. [Figure 90A] 10 is a graph of a temperature profile through a sintering furnace according to another exemplary embodiment; [Figure 90B] Schematic diagram of the sintering furnace of FIG. [Figure 91A] 1 is a side perspective view of a sintered material according to an exemplary embodiment; [Figure 91B] 1 is a side perspective view of a sintered material according to an exemplary embodiment; [Figure 92] 1 is a side view of a sintered material according to an example embodiment; [Figure 93] 1 is a schematic diagram of an electronic component in the form of a battery, according to an example embodiment; [Figure 94] 1 is a graph of a sintering schedule according to an exemplary embodiment; [Figure 95] 1 is a graph of a sintering schedule according to an exemplary embodiment; [Figure 96] 1 is a graph of ionic conductivity versus sintering temperature for a number of sintered articles according to exemplary embodiments; [Figure 97] 1 is a graph of sintering temperature versus percentage of cubic garnet for a number of sintered articles according to exemplary embodiments; [Figure 98] 1 is a side perspective view of a surface of a sintered material according to an exemplary embodiment; [Figure 99] 1 is a side perspective view of a surface of a sintered material according to an exemplary embodiment; [Figure 100A] 1 is a top view of a surface of one side of a sintered material according to an example embodiment; [Figure 100B] 1 is a top view of a surface of one side of a sintered material according to an example embodiment; [Figure 101A] 100B is a top view of the surface of the other side of the sintered material of FIG. 100A. [Figure 101B] 100B is a top view of the surface of the other side of the sintered material. [Figure 102] 1 is a side view of a sintered material according to an example embodiment; [Figure 103] A digital image of a sintered material having a layer that provides a smooth surface, according to an example embodiment. [Figure 104] 1 is a schematic diagram of an electronic component in the form of a stack of sintered articles, according to an exemplary embodiment; DETAILED DESCRIPTION OF THE INVENTION

[0017] With general reference to the drawings, various embodiments of systems and processes for producing long, thin, and / or wide sintered articles are shown and described. Herein, applicants use the term "sinter" to refer to a process in which particles or grains (e.g., of powdered or granular material) are coalesced (e.g., directly bonded to one another) into a solid or porous body by heating the particles or grains so that their crystalline structure remains within the coalesced body without completely liquefying them. However, aspects of the present technology can also be used to produce amorphous materials, such as those that are difficult or impossible to process using conventional manufacturing techniques, as would be intuitive to one skilled in the art of inorganic materials processing. Furthermore, applicants have discovered that novel sintered articles with diverse properties can be formed using the systems / processes described herein that were not previously achievable using conventional technology. Specifically, Applicant has developed material handling systems and processes that can provide extremely precise levels of control over the various conditions / forces experienced by a material during the formation of a sintered article, and that this precise control / material handling enables the production of long, thin, and / or wide sintered materials that were previously thought to be unattainable with conventional systems. Additionally, articles produced using the techniques disclosed herein may possess other unique qualities, such as: strength, which may be due to low defect counts, purity, which may be due to controlled airflow and sintering duration, and purity-related properties such as dielectric constant and impermeability, consistency along their length and / or width, etc., with respect to flatness, thickness, roughness, grain size, etc., and other unique attributes.

[0018] Generally, the systems described herein utilize an input roll of web-supported substrate tape wound on a spool or reel. As described in more detail below, the web-supported substrate tape includes a substrate tape material including granules of inorganic material (e.g., granules of a ceramic material, granules of a polycrystalline ceramic material, granules of a metal, or granules of a synthetic material) bound by an organic binder material, the substrate tape material being supported on a carrier web (e.g., a sheet of a polymeric material). The input roll of web-supported substrate tape is unwound, and the carrier web / backing is carefully separated from the substrate tape material. Applicant has discovered that by precisely controlling the separation of the carrier web from the substrate tape with little or no distortion of the substrate tape, it is possible to produce sintered articles having highly consistent / controlled properties (e.g., thickness, flatness, density, shape, etc.) along their length. That said, in other contemplated embodiments, the substrate tape may not be web-supported and / or may not be in a roll, such as when formed in a linear fashion along a production line prior to sintering.

[0019] Following removal of the carrier web, the free-standing substrate tape (comprising particles of inorganic material supported by an organic binder material) is moved through a binder removal station. Generally, the binder removal station applies heat to the free-standing substrate tape in a manner that removes or chemically alters the organic binder, such that the tape material exiting the binder removal station is unbound. By "unbound," applicants mean that the binder material has been removed; however, the unbound tape may still be held together, for example, by char from burned binder, or by interweaving or bonding between the inorganic particles, or by other means (e.g., electrostatic forces, air pressure). After removal of the organic binder, the unbound tape material is moved into a sintering station, which applies heat to the unbound tape material, which sinters (e.g., fully or partially) the inorganic particles to form a sintered article, which exits the sintering station.

[0020] Applicant has surprisingly discovered that even after the organic binder is removed, the inorganic grains support themselves as unbound tape material; and / or the tape may be supported in other ways, as described above. However, after organic binder removal, the unbound tape material is, or may be, extremely delicate before sintering. Applicant has therefore further identified a novel debinding and sintering station configuration that allows for the delicate, unsupported tape material to be handled in a manner that achieves the production of extremely high-quality sintered articles. (By "unsupported" in the immediately preceding sentence, Applicant means that it is not supported by an organic binder after binder removal or burnout.) In particular, it produces wide, long, high-quality sintered articles that are suitable for roll-to-roll handling without introducing significant distortion or damaging the articles during binder removal or sintering.

[0021] In particular, applicant has determined that airflows (e.g., turbulent airflows generated by thermal gradients) within the debinder station and / or sintering station can impinge on the tape material, causing distortion or breakage of the tape material. Applicant has further discovered that a highly horizontal process path within the debinder station and / or sintering station reduces or eliminates turbulent airflows, thereby producing or capable of producing sintered articles without significant distortion. Applicant has further determined that the elimination of airflow-based distortion is particularly important when forming wide sintered articles (e.g., articles greater than 5 mm wide), because applicant believes that the susceptibility to airflow-based distortion increases as the width of the tape material increases. Applicant has further determined that the elimination or reduction of airflow-based distortion is particularly important to enable roll-to-roll processing, because applicant has discovered that even small levels of distortion can cause the sintered article to break or otherwise prevent it from being properly wound onto the take-up reel (also known as the tape-up reel).

[0022] The identification of horizontal positioning of the tape during binder removal and / or sintering was a surprising discovery given the inorganic substrate materials and past sintering techniques. For example, some tape material sintering may utilize downwardly inclined positioning of the tape material (e.g., a 12-20° downward incline) as a means to utilize gravity to pull the delicate tape material through the heating step of the system, presumably for the purpose of applying a uniformly distributed force across the tape material to pull the tape material through the heating step of the process.

[0023] However, applicants have discovered that tilting the heating portion of the sintering system can create turbulent airflow as hot air rises through the channels of the heating system holding the tape material. This flowing air can then impinge on the tape material, potentially creating distortions or damaging the tape. Furthermore, applicants have discovered that the incidence of airflow due to distortions created in sintered tapes formed using non-horizontal heating configurations can increase as the width of the tape material increases. That said, aspects of the technology disclosed herein may be used with systems that include non-horizontal heating channels or systems, such as debinder stations. Furthermore, aspects of the technology disclosed herein, such as unique materials and form factors (e.g., thin ribbons of garnet or other materials, or other geometric shapes), can also be produced using non-horizontal heating channels or systems.

[0024] Applicant has attempted to sinter wider tapes (e.g., tapes greater than 5 mm wide, and specifically, a 25 micrometer thick, 32 mm wide green tape containing zirconia-3 mol% YO inorganic particles) using the tilted configuration. As shown in Figure 1, when partially sintered at 1250°C, the resulting partially sintered article had significant, periodic distortions or bubbles along the length of the tape. The distortion height was on the order of more than 1 mm, large enough to prevent the tape from being wrapped around a core 3 to 6 inches (7.62 to 15.24 cm) in diameter. Applicant believes that during the heat-up stage of tape processing (e.g., during sintering and binder removal), hot air was blown upward onto the tape's underside, tilted support surface, causing the bubbles to form as the turbulent airflow pushed the tape upward.

[0025] In addition to controlling airflow, Applicant has determined that controlling the thermal profile within the debinder station and / or sintering station is, or can be, important to forming a high-quality sintered article. In particular, Applicant has discovered that when heating wide tape materials in a roll-to-roll process such as that described herein, it is necessary, for at least some materials and / or geometries disclosed herein, such as at least some thin, wide inorganic tape, to precisely control the thermal stresses to which the tape material is exposed during sintering to limit distortion or breakage that might otherwise occur as the tape shrinks / densifies during sintering. As an example, shown in FIG. 2, a section of ceramic tape (specifically, alumina tape) including a portion of the tape in transition from green to sintered material is shown as having been formed using a process in which the temperature is rapidly increased in a high-temperature sintering zone. As shown in FIG. 2, this rapid temperature increase can cause or lead to distortion or cross-web shape changes due to stresses within the tape material as the tape is sintered following the rapid temperature increase in the sintering zone. That said, in other embodiments, such as those involving different materials (e.g., lithium garnet), a rapid temperature increase, such as through reduced exposure to oxidation or impurities, may be beneficial, and distortion may be controlled by other factors, such as airflow control and narrower tape widths.

[0026] Thus, as shown and described below, applicants have determined that by utilizing a sintering furnace having multiple independently controlled heating zones and / or multiple independently controlled sintering furnaces, wide and long segments of tape material can be sintered at high process throughput rates without significant distortion and / or breakage. Similarly, the debindering furnace and sintering furnace are designed and positioned relative to one another to limit the thermal shock (e.g., exposure to sudden temperature gradients) to which the tape is exposed as it transitions between different heated zones in the systems described herein.

[0027] Following sintering, the wide sintered tape can be wound or spooled onto a take-up reel, which forms a roll of sintered tape material. In contemplated embodiments, the roll is cylindrical or other shaped, such as when wound around a non-circular geometric shape, such as an ellipse, a triangle with rounded apexes, etc. The high quality (e.g., low distortion) of the tape formed by one or more systems described herein allows, at least in some embodiments, the tape to be wound into a roll in a manner that allows the roll of sintered tape to be conveniently and efficiently used in subsequent manufacturing processes, such as for use as a downstream substrate in a roll-to-roll manufacturing process. Applicant has discovered that the high level of consistency in width, length, thickness, shape, and / or flatness, and / or other attributes (purity, strength, impermeability, dielectric performance) of the tape or other articles produced by one or more systems described herein allows for the tape to be wound onto a take-up reel. In contrast, a tape with a high level of distortion or irregularity may be, or have a tendency to break or distort to form an inconsistent roll of tape, and may be unsuitable for being taken onto a reel to form a roll of sintered tape. That said, some possible non-horizontal sintering systems, particularly those employing the techniques disclosed herein, can achieve distortion-free tape, for example, when the airflow is controlled, the tape is sufficiently thin and sufficient tension is applied, the sintering rate and temperature are controlled, etc., as disclosed herein.

[0028] Finally, some conventional sintered articles are formed in a system in which individual pieces of green tape or green material are placed on a surface called a setter board and placed in a furnace where the organic binder is burned off and the inorganic particles are sintered. Applicant has determined that roll-to-roll formation of sintered articles offers numerous advantages not found in individual, conventionally sintered articles. For example, wide, wound rolls of sintered articles can be formed at high throughput rates (e.g., rates of 6 inches (15.24 cm) per minute or greater). Furthermore, one or more systems / processes described herein form wide, thin sintered materials (e.g., thin ceramics and / or sintered articles), which enable the sintered articles to be used as substrates to form small, low-cost devices (e.g., semiconductor devices, batteries, etc.). Similarly, providing a roll of sintered material enables the sintered material to be used as an input substrate roll for high-throughput downstream manufacturing processes, further enabling the sintered articles described herein to be used to form downstream articles at high speed and / or low cost.

[0029] System Overview Referring to Figure 3, a system 10 for producing sintered tape articles is illustrated according to one exemplary embodiment. Generally, green tape material is fed into the system 10 at an input side, a separation system 12, and the green tape material moves through the system 10 generally in a process direction 14. Within the separation system 12, a source 16 of continuous tape material 18 ("continuous" as used herein means a long length, e.g., 300 cm or more, which may be provided in the form of a spool or belt) is provided and fed into a downstream portion of the system 10.

[0030] Typically, the continuous tape material 18 includes a layer of substrate tape material 20, which includes granules of inorganic sinterable material bound together by an organic binder (e.g., polyvinyl butyral, dibutyl phthalate, polyalkyl carbonate, acrylic polymer, polyester, silicone, etc.). The substrate tape material 20 of the continuous tape material 18 is, or can be, supported on a carrier web or backing layer 22. As described in more detail below, in specific embodiments, the system 10 is configured to form sintered articles that are long, wide, and / or thin; in such embodiments, the substrate tape material 20 entering the system 10 is also relatively long, wide, and / or thin. For example, in specific embodiments, the substrate tape material 20 has a width greater than 5 mm, greater than 10 mm, greater than 40 mm, or greater than 125 mm. In specific embodiments, the substrate tape material 20 has a length greater than 10 meters (m), specifically greater than 30 m, and more specifically greater than 60 m. In specific embodiments, the substrate tape material 20 has a thickness between 3 micrometers and 1 millimeter. Furthermore, the incoming substrate tape material 20 has a porosity greater than the porosity of the sintered article produced by the system 10. In other contemplated embodiments, the substrate tape material 20 may have a width less than 5 mm, e.g., at least 0.5 mm, at least 1 mm, at least 2.5 mm, or in some such embodiments, less than 0.5 mm. Similarly, the tape may have a different thickness and / or length and / or porosity. In some embodiments, the tape material 20 may have a non-rectangular cross-section perpendicular to its length, e.g., a circular, oval, parallelogram, diamond, etc., where the width of such embodiments refers to the largest cross-sectional dimension perpendicular to the length and the thickness is the smallest cross-sectional dimension perpendicular to the length.

[0031] The separation system 12 includes a carrier web removal station 24. At the carrier web removal station 24, the carrier web 22 is separated from the substrate tape material 20, and the removed carrier web 22 is, or can be, wound onto a take-up reel 26. Generally, the carrier web removal station 24 includes: a tension isolator 28, which can include a vacuum drum; and a stripper 30, which removes the carrier web 22 in a manner that does not distort or compress the substrate tape material 20 and that isolates the substrate tape 20 from the tension in the carrier web 22 generated by the take-up reel 26. Following separation from the carrier web 22, the substrate tape 20 becomes, or can become, a free-standing substrate tape that includes particles of inorganic material supported by an organic binder material, but does not include a carrier web or other support structure to hold the tape material together during downstream processing through the system 10.

[0032] The freestanding substrate tape 20 moves, or can move, into the ultra-low tension control system 32. Generally, the freestanding substrate tape 20 is a relatively delicate structure that is pulled through the system 10 by the action of various spools, reels, rollers, etc. This pulling action applies tension to the freestanding substrate tape 20. Applicant has discovered that it is, or can be, advantageous to apply a uniform, low level of tension (e.g., in grams; 0.1 grams to less than 1 kg; at least 1 gram, at least 5 grams, and / or 100 grams or less, depending on the size of the tape and the strength of the binder) to the freestanding substrate tape 20 because this improves various properties of the final sintered article, such as lateral profile and flatness. However, due to the delicate nature of the freestanding substrate tape 20 (which becomes even more delicate after binder removal, as explained in more detail below), this low level of tension is precisely controlled to provide sufficient tension to the tape 20 to limit distortion during binder removal / sintering of the tape 20, while limiting the maximum tension to ensure that the tape 20 does not break. That said, other contemplated embodiments apply higher tensions, for example, for stronger tapes, or even zero tension other than that due to the weight of the tape itself.

[0033] 3, the tension control system 32 includes an ultra-low tension dancer 33 that utilizes a low weight, low inertia carbon fiber roller. The ultra-low tension dancer 33 may include air bearings, which facilitate low friction rotation of the carbon fiber roller of the tension dancer 33. In other embodiments, a free loop of material or a vacuum box may be utilized to provide a consistent, gram-level of tension to the tape 20.

[0034] Following the tension control system 32, the freestanding substrate tape 20 moves into a binder removal station 34. Typically, the binder removal station 34 includes one or more heating elements that deliver heat to channels formed by the station 34. The heat in the binder removal station 34 chemically alters and / or removes at least a portion of the organic binder material of the freestanding substrate tape 20, resulting in an unbonded tape 36 exiting the binder removal station 34. Typically, the unbonded tape 36 includes particles of inorganic material with little or no organic binder remaining. Applicant has discovered that the unbonded tape 36, even in the absence of an organic binder, holds itself together in such a manner that it can be moved into the sintering station 38 using tension control, airflow control, proximity of the binder removal station 34 to the sintering station 38 and temperature control therebetween, and the orientation and alignment of the tape with stations 34, 38 as shown in FIG. 3 .

[0035] Generally, the binder removal station 34 is positioned and controlled to impart only small strain to the tape 20 as it traverses the binder removal station 34. Additionally, the binder removal station 34 may include a heating element to remove volatile organic compounds without applying too much heat too quickly, which could otherwise ignite the organic binder compounds. Ignition may also be controlled by air flow.

[0036] Additionally, the debinder station 34 is positioned relative to the sintering station 38 such that the unbonded tape 36 is exposed to a small thermal shock or temperature gradient during movement from the debinder station 34 into the sintering station 38 (e.g., with spaced, but linearly aligned paths and respective openings that are aligned and / or within 1 meter, 10 cm, 2 cm, and / or closer to each other). Applicant has discovered that due to the delicate nature of the unbonded tape 36, limiting the thermal shock experienced by the tape 36 between stations 34 and 38 further provides for the production of a flat, consistent, and / or distortion-free sintered tape by limiting / eliminating distortion that would occur due to the temperature gradients experienced between stations 34 and 38.

[0037] In various embodiments, the temperature within station 34 is precisely controlled to achieve the desired properties of the tape 36 exiting station 34. In various embodiments, the temperature within station 34 is between 200 degrees Celsius (°C) (or about 200°C) and 500°C (or about 500°C), and station 34 is heated to provide a temperature profile along its length such that little or no binder remains in the tape material exiting binder removal station 34. Additionally, in some embodiments, some sintering of the inorganic material grains (e.g., shrinkage, increased density, decreased porosity, etc.) may occur during passage through binder removal station 34.

[0038] Following binder removal in station 34, unbonded tape 36 moves into sintering station 38. Typically, sintering station 38 includes one or more heating elements (e.g., see further discussion below regarding heating elements and their types) that heat sintering station 38 to temperatures above 500°C (e.g., 500°C (or about 500°C) to 3200°C (or about 3200°C, e.g., 3200°C ± 10%)), causing sintering of the grains of inorganic material in unbonded tape 36. Generally, the porosity of the inorganic material decreases during sintering. This decrease in porosity may also cause shrinkage (e.g., a decrease in width, thickness, length, etc.) of the tape material as it is sintered in sintering station 38. For some materials, the modulus of elasticity may increase, strength may increase, or the porosity morphology may change during sintering, without a significant decrease in porosity or significant shrinkage. In some embodiments, sintering station 38 converts tape 36 into a partially, but not completely, bisque-fired material.

[0039] Applicant has discovered that as the unbonded tape 36 passes through the sintering station 38, the unbonded tape 36 is susceptible to deformation or breakage that may be caused by various forces that the unbonded tape 36 encounters during sintering. In particular, as discussed above, Applicant has discovered that forces caused by turbulent airflow through the sintering station 38 are one source of significant deformation, and Applicant has discovered that stresses within the tape 36 during sintering are another significant potential source of deformation. Based on these discoveries, Applicant has arranged or configured the sintering station 38 in various ways to limit these forces in order to produce sintered articles having acceptably low levels of distortion.

[0040] As particularly shown in FIG. 3 , the sintering station 38 is disposed in a generally horizontal configuration, such that the unbonded tape 36 passes through the station 38 in a generally horizontal orientation. Applicant has discovered that maintaining a generally horizontal configuration of the sintering station 38 reduces or minimizes turbulent airflow, which leads to the formation of a sintered tape material at the output of the sintering station 38 that has a low level of deformation, a low level of cross-tape profile, and / or is flat. In various embodiments, Applicant believes that for various wide tape materials, low turbulence and resulting low distortion can be achieved by maintaining the angle of the tape material process path relative to the horizontal plane to less than 10°, specifically less than 3°, and more specifically less than 1°. In some embodiments, the tape may travel on a generally horizontal, arcuate path, as described below. In still other embodiments, the path through the sintering station 38 may be inclined more than 10° above the horizontal, as described above.

[0041] 3, the debinder station 34 is also positioned in a generally horizontal position so that turbulent airflow does not cause distortion, breakage, etc. during heating using the debinder station 34. Similarly, the debinder station 34 is aligned vertically with the sintering station 38 (i.e., so that their respective openings are aligned and face each other), so that the unbonded tape 36 is maintained in a horizontal position as the tape 36 moves from the debinder station 34 to the sintering station 38.

[0042] Additionally, Applicant has discovered that if the unbonded tape 36 is exposed to a temperature profile along the length of the sintering station 38 that has rapid temperature increases / decreases, high levels of stress are or can be generated within the tape 36, which can cause or lead to deformation or breakage of the tape 36 during sintering. Furthermore, Applicant has discovered that sintering stresses increase the risk of deformation as the width of the tape 36 increases. Based on these discoveries, Applicant has determined that by utilizing the sintering station 38 with multiple independently controllable heating elements (and possibly multiple sintering furnaces), it is possible to create a temperature profile along the length of the sintering station 38 that keeps the stresses imposed by the tape 36 below a certain threshold that Applicant has discovered is prone to causing deformation or breakage based on the particular tape configuration.

[0043] Following passage through the sintering station 38, the partially or fully sintered tape material 40 exits the sintering station 38 and enters an output intake system 42. The sintered tape material 40 is wound onto an intake reel 44. An interlayer support material 46 is unwound from the reel 48. The support material 46 is wound onto the intake reel 44 such that a layer of the support material 46 is, or may be, located between each layer or at least some layers of the sintered tape material 40 on the intake reel 44. This arrangement forms a roll or spool 50 of supported sintered tape material. Generally, the support material 46 is a conformable, relatively high-friction material that allows the sintered tape material 40 to be held on the intake reel 44 with relatively low winding tension. The conformability of the support material 46 allows it to compensate for any cross-web shape that may be present in the tape 40 (sintered tape material 40). The support material 46 also increases friction between adjacent layers of the tape 40 (sintered tape material 40) on the reel 44, which limits the tape 40 (sintered tape material 40) from slipping / stretching from the reel 44. Applicant believes that without the support material 46, the sintered tape material 40 would tend to slip (e.g., stretch) off the spool 50, at least in part because the sintered tape 40 (sintered tape material 40) has a relatively high elasticity, which limits the ability of the tape 40 (sintered tape material 40) to stretch under winding tension, which would tend to or could compromise roll integrity.

[0044] As described herein, system 10 is configured to form sintered tape material 40 that has low distortion, low risk of breakage, consistent properties along its length, etc., regardless of the width and / or length of the sintered article. As applicant has discovered, the risk of tape distortion and breakage at various stages of system 10 can increase, particularly as the tape width increases. For example, in specific embodiments, sintered tape 40 (sintered tape material 40) has a width greater than 5 mm, greater than 10 mm, greater than 40 mm, or greater than 125 mm, and various configurations of system 10 described herein limit the risk of deformation or breakage regardless of the width of the tape material. In other embodiments, the sintered tape has a width less than 5 mm and / or at least 0.5 mm, e.g., at least 1 mm, e.g., at least 2 mm.

[0045] Additionally, one or more of the various material handling and heating mechanisms of the system 10 enable the formation of sintered tape 40 (sintered tape material 40) at high throughput rates. In particular embodiments, the roll-to-roll process of the system 10 enables the production of sintered tape at rates believed to be significantly faster than other sintering processes, such as conventional tunnel kiln processing, at least in some cases. In particular embodiments, the system 10 is configured to produce sintered tape 40 at rates of at least 6 inches (15.24 cm) per minute, at least 8 inches (20.32 cm) per minute, at least 19 inches (48.26 cm) per minute, at least 29 inches (73.66 cm) per minute, and at least 59 inches (149.86 cm) per minute. In still additional specific embodiments, the system 10 is configured to produce sintered tape 40 at a rate of at least 3 inches (7.62 cm) per minute for substrate tapes 20 greater than 50 mm wide, at least 5 inches (12.7 cm) per minute for substrate tapes 20 between 35 mm and 50 mm wide, at least 9 inches (22.86 cm) per minute for substrate tapes 20 between 15 mm and 35 mm wide, and at least 10 inches (25.4 cm) per minute for substrate tapes 20 between 5 mm and 15 mm wide. In further specific embodiments, the system 10 is configured to produce sintered tape 40 at a rate of at least 1 inch (1.54 cm) per minute (ipm) for substrate tapes 20 greater than 50 mm wide, at least 1.5 inches (3.81 cm) per minute for substrate tapes 20 between 35 mm and 50 mm wide, at least 2 inches (5.08 cm) per minute for substrate tapes 20 between 15 mm and 35 mm wide, and at least 3 inches (7.62 cm) per minute for substrate tapes 20 between 5 mm and 15 mm wide.

[0046] Support Web Removal Station Forming embodiments of the sintered articles described herein includes applying a uniform web tension to the substrate tape material before and after sintering. A separation system according to one or more embodiments of the present disclosure is designed to apply such uniform web tension, along with a uniform speed, to the substrate tape as it separates from the supporting carrier web. Removal of the web support as disclosed herein therefore achieves a geometric consistency in the substrate tape material, which reduces or eliminates instances of substrate tape necking or shrinkage and reduces or eliminates instances of equipment surface features being imprinted onto the substrate tape, which would otherwise be present in the sintered tape. That said, the techniques disclosed herein can be used without a support web removal station to produce novel sintered tapes as disclosed herein, where the tape may have features resulting from the absence of the support web removal station, such as thickness variations, repetition of imprinted surface features, etc.

[0047] As described above, system 10 generally includes a support web removal station on the input side of system 10. One aspect of a support web removal station includes a separation system 12. Referring to FIG. 4, separation system 12 is configured to separate substrate tape material 20 from carrier web 22 so that the substrate tape material 20 can be processed downstream. In one or more embodiments, a source 16 of continuous tape material 18 to be separated is provided. As more clearly shown in FIG. 5, continuous tape material 18 includes substrate tape material 20 supported on carrier web 22. In FIG. 4, source 16 is provided in the form of a spool, which unwinds continuous tape material 18 toward carrier web removal station 24 (which includes tension breaker 28 and peeler 30). In one or more embodiments, source 16 may include a belt or other form for supplying continuous tape material. In other contemplated embodiments, the source of the substrate tape material may be another station on a manufacturing line that continuously produces or is capable of continuously producing substrate material, forming and conditioning the substrate tape for subsequent handling in one or more of the systems disclosed herein. Still other contemplated embodiments may have substrate tape material separated by organic material that is burned or otherwise removed, such as by a binder removal station disclosed herein.

[0048] According to an exemplary embodiment, the substrate tape material 20 comprises granules of an inorganic material (as described herein), the granules being sinterable and bound together by an organic binder. The carrier web 22 may comprise a polymer, paper, or a combination of polymer and paper materials. In some embodiments, the substrate tape material comprises a polymer in an amount less than the polymer content of the carrier web 22, where the polymer content is measured in volume percent of each material. According to an exemplary embodiment, the substrate tape material 20 and the carrier web 22 each have, for a substrate tape having a continuous cross-sectional geometry, e.g., rectangular or elliptical (e.g., where edges can be removed after sintering to form straight sides), a respective thickness (t), defined as the distance between the first and second major surfaces; a respective width (W), defined as a first dimension of one of the first or second surfaces perpendicular to the thickness; and a respective length (L), defined as a second dimension of one of the first or second surfaces perpendicular to both the thickness and the width. In other contemplated embodiments, tapes of inorganic sinterable material may be held together by an inorganic binder, such as an inorganic binder that becomes part of the sintered tape after processing in system 10. In yet other contemplated embodiments, tapes of inorganic material may be held together by bonding the inorganic material to itself, such as by using partially sintered bisque tape rather than green tape, as disclosed herein.

[0049] As described herein, according to certain exemplary embodiments, the carrier web 22 provides, or can provide, the primary contact surface for transporting the continuous tape material through the separation system 12, and particularly for transporting the continuous tape material through the carrier web removal station 24. In other words, in at least some such embodiments, the carrier web 22 is primarily contacted, and the base tape material 20 is left substantially untouched, and thus is substantially free of defects or blemishes that are or may be created by contact, such as repeating surface features imprinted by the surface of a wheel or roller on the base material of the tape that may be detectable in the finished sintered product. Other embodiments may include such defects or blemishes when aspects of the technology disclosed herein are used, such as without the carrier web removal station 24. When source 16 is a spool, the continuous tape material has a relatively low first tension (as described further herein) and tends to unwind from a wound state at a relatively high rate, even when the continuous material is held at a constant, low tension. Separation system 12 acts, or may act, as a brake to reduce or otherwise control or limit the rate at which the continuous tape material unwinds from source 16.

[0050] According to at least some such exemplary embodiments, the carrier web removal station 24 includes a tension breaker 28 positioned near and downstream from the source 16 and a peeler 30 positioned downstream from the tension breaker 28. The tension breaker 28 and peeler 30 separate the carrier web 22 from the substrate tape material 20 without damaging the substrate tape material. In particular, the tension breaker 28 is designed and used to grip the carrier web and regulate the speed of the continuous tape material through the separation system. In one or more embodiments, after the carrier web 22 is separated from the substrate tape material, the speed at which the carrier web 22 is withdrawn after separation from the substrate tape material 20 is controlled to maintain a constant tension within the carrier web 22, and therefore within the continuous substrate tape material 20. In one or more embodiments, the tension breaker 28 isolates the separation of the carrier web 22 from the substrate tape material 20 from the quality of the substrate tape material 20 coming from the source 16. Without the use of the tension breaker 28, any or some discontinuity in the quality of the winding of the continuous tape material (i.e., excessive looseness of the winding, which may result in cinching during unwinding or feeding into the stripper 30) can cause fluctuations in tension and speed in the stripper 30.

[0051] According to certain exemplary embodiments, the continuous tape material 18 is fed to the tension interrupter 28 at a first tension, and the tension interrupter of one or more embodiments is structured or configured to apply a second tension to the carrier web 22, the second tension being greater than the first tension of the continuous tape material 18, as the continuous tape material 18 is transported to the peeler 30. In some embodiments, the second tension (i.e., pulling force) is at least 20% greater than the first tension and / or at least 25 milliNewtons (mN), e.g., at least 100 mN, e.g., at least 200 mN. According to some such embodiments, the second tension is applied to the carrier web 22, but not at all, or at least substantially not, to the base tape material. In one or more embodiments, the base tape material 20 maintains the first tension as the continuous tape material moves along the interrupter 28. In one or more embodiments, as the continuous tape material moves along tension isolator 28, the base tape material has no or no tension, or has no or no tension greater than the tension required to support its own weight, or substantially no or no tension greater than the tension required to support its own weight, for example, less than 1 Newton (N) greater than the tension required to support its own weight. Thus, tension isolator 28 creates a first tension zone 17 between tension isolator 28 and source 16, and a second tension zone 19 between tension isolator 28 and peeler 30. The tension applied to carrier web 22 in first tension zone 17 is less than the tension applied to carrier web 22 in second tension zone 19. In one or more embodiments, the tension (ie, tensile stress) applied to carrier web 22 in second tension zone 19 is less than or equal to about 2.5 pounds per linear inch (PLI) (446.45 g / cm).For example, in one or more embodiments, the tension applied to the carrier web 22 is about 2.4 PLI (428.592 g / cm) or less, about 2.3 PLI (410.734 g / cm) or less, about 2.2 PLI (392.876 g / cm) or less, about 2.1 PLI (375.018 g / cm) or less, about 2 PLI (357.16 g / cm) or less, about 1.8 PLI ​​(321.444 g / cm) or less, about 1.6 PLI (285.728 g / cm) or less, about 1.5 PLI (267.87 g / cm) or less, about 1.4 PLI (250.012 g / cm) or less, about 1.2 PLI (214.296 g / cm) or less, or about 1 PLI (178.58 g / cm) or less. In one or more embodiments, the first tension is about 50% or less (e.g., about 45% or less, about 40% or less, about 35% or less, about 30% or less, or about 25% or less) of the second tension. In some embodiments, the tension (i.e., pulling force) applied to carrier web 22 in second tension zone 19 is at least 20% greater than the tension applied to carrier web 22 in first tension zone 17, and / or is at least 25 milliNewtons (mN), e.g., at least 100 mN, e.g., at least 200 mN greater. In one or more embodiments, a (slight) additional tension is applied to the substrate tape material beyond the tension applied to the substrate tape material by the application of tension to carrier web 22. In such embodiments, the carrier web may be stretched, such as by the application of tension to the carrier web, which generates some tension in the substrate tape material, e.g., where a substantial portion of the tension is borne by the carrier web.

[0052] In one or more embodiments, the tension isolator 28 applies a tension to the carrier web 22 that is greater than the tension applied to the base tape material 20. In some embodiments, the tension isolator applies a tension to the carrier web that is about twice or more the tension applied to the base tape material as the continuous tape material is moved from the source 16 to the peeler 30. In some embodiments, the tension isolator 28 applies a tension to the carrier web 22 that is at least 20% greater than the tension applied to the base tape material 20 and / or at least 25 milliNewtons (mN), e.g., at least 100 mN, e.g., at least 200 mN greater. As can be intuitively understood, "tension" as used herein generally refers to the longitudinal or axial pulling apart of a material; where units of force are given herein, tension refers to tensile force; where units of stress are given, tension refers to tensile stress; and / or tension may be given other units, such as pounds per linear inch or metric equivalent, to refer to another related parameter.

[0053] In the embodiment shown in FIG. 4 , the tension breaker 28 may include a vacuum drum 25. As shown in FIG. 6 , in one or more embodiments, the vacuum drum 25 is rotated to move the continuous tape material by a drive motor input 27 connected to the vacuum drum by a bearing housing 29. As shown in FIG. 7 , the vacuum drum may include an outer surface including a plurality of vacuum holes 7 arranged in a uniform distribution. The vacuum holes 7 may be formed along a plurality of axial grooves 8 and / or radial grooves that intersect with each other at the vacuum holes 7. Vacuum is supplied to the vacuum drum 25 via a vacuum source (e.g., a vacuum blower), which grips the carrier web 22 through the vacuum holes 7, thereby facilitating tensioning the carrier web as described herein. In one or more embodiments, the distribution of the vacuum holes 7 and the configuration of the vacuum drum (including the diameter and vacuum force used) apply or help apply a uniform tension to the carrier web along the width of the carrier web. Through this action and configuration, the vacuum drum regulates the speed of the carrier web (and therefore the continuous tape material) as it moves through the separation system 12. In one or more embodiments, the tension interrupter pulls the continuous tape material from the source along the first tension zone 17. Any or some discontinuities in the delivery of the substrate tape material from the source 16 to the stripper 30, such as loose wrapping (which could result in cinching during transfer from the source to the stripper), do not or cannot affect the separation process. The vacuum drum 25 provides a bonding or traction force between the tape material (e.g., the carrier web) and the vacuum drum 25 in addition to normal force and friction proportional to the tension, thus increasing the bonding or traction force without having to increase the tension of the tape material. Due to at least this advantage, Applicant believes that using a vacuum drum to control the bonding or traction force between the tape material and the roller (i.e., the vacuum drum) during the step of separating the substrate tape from the carrier web is a unique and effective process for protecting and controlling the shape of the substrate tape, which can be particularly delicate.That said, aspects of the present technology may be used to produce novel sintered products, such as tapes that do not have marks of separation without using a vacuum drum as disclosed herein, such as repeating defects from rollers, variations in tape thickness, shorter tape lengths, etc.

[0054] In one or more embodiments, tension breaker 28 increases the tension of the continuous tape material (more particularly, of the carrier web, or primarily of the carrier web) along second tension zone 19 as the continuous tape material is transported to peeler 30. In the embodiment shown in FIG. 4, separation system 12 includes a load controller 21 for maintaining tension on the carrier web. In one or more embodiments, load controller 21 is also used to adjust the speed of intake reel 26 relative to tension breaker 28.

[0055] In one or more embodiments, the peeler 30 is positioned downstream of the tension breaker 28 and orients the carrier web 22 in an unwind direction A and the substrate tape material 20 in a downstream process direction B that is different from the unwind direction A, as shown in Figure 8. In one or more embodiments, the unwind direction A and the downstream process direction form an angle C that is greater than about 90° (e.g., 95° or more, 100° or more, 110° or more, or about 120° or more).

[0056] In one or more embodiments, the peeler 30 includes a sharp knife or edge for creating a separation line in the substrate tape material, such as at or near the apex of angle C, shown as tip 31. In one or more embodiments, the sharp knife or edge creates a separation line in the substrate tape material but not in the carrier web just prior to or near tip 31, as shown in FIG. 8. In one or more embodiments, the tip has a radius of about 0.05 inches (1.27 mm) or less (e.g., about 0.04 inches (1.016 mm) or less, about 0.035 inches (0.889 mm) or less, about 0.03125 inches (0.79375 mm) or less, about 0.03 inches (0.762 mm) or less, or about 0.025 inches (0.635 mm) or less).

[0057] As the continuous tape material passes tip 31, tip 31 separates carrier web 22 from substrate tape material 20. In one or more embodiments, tip 31 separates carrier web 22 from substrate tape material 20 before orienting the carrier web in unwind direction A and orienting the substrate tape material in downstream process direction B. In one or more embodiments, tip 31 separates carrier web 22 from substrate tape material 20 simultaneously orienting carrier web 22 in unwind direction A and orienting substrate tape material 20 in downstream process direction B.

[0058] 4, the separation system 12 includes an intake reel 26 for collecting the separated carrier web 22. In the illustrated embodiment, an optional idle roller 23 may be used to further control and maintain tension in the carrier web 22. In one or more embodiments, a sensor 15 may also be used to control and maintain tension in the carrier web as the diameter of the source 16 decreases and the diameter of the intake reel 26 increases as more continuous tape material is conveyed through the separation system.

[0059] Another aspect of the support web removal station relates to a method for separating two materials (e.g., a substrate tape material and a carrier web). In one or more embodiments, the method includes: feeding continuous tape material 18 to a tension breaker 28; applying a tension to carrier web 22 using the tension breaker that is higher than the tension applied to substrate tape material 20; and orienting the carrier web to move in an unwinding direction and orienting the substrate tape material in a downstream process direction different from the unwinding direction, as described herein. In one or more embodiments, the method includes: orienting the carrier web in the unwinding direction and separating the carrier web from the substrate tape material before orienting the substrate tape material in the downstream process direction. In one or more embodiments, the method includes: orienting the carrier web in the unwinding direction and separating the carrier web from the substrate tape material simultaneously with orienting the carrier web in the unwinding direction and orienting the substrate tape material in the downstream process direction. As taught above, embodiments of the present method have the carrier web in contact with a vacuum drum. In other embodiments, the tape material may have a carrier web on both sides of the tape, and the elements of the separation station can be repeated and used to remove both carrier webs.

[0060] In one or more embodiments, the method includes applying no, almost no, or negligible tension (as disclosed above) to the base tape material. In one or more exemplary embodiments, the method includes applying no, almost no, or negligible tension to the base tape material as it moves from source 16 to tension breaker 28 along first tension zone 17. In one or more exemplary embodiments, the method includes applying no, almost no, or negligible tension to the base tape material as it moves from tension breaker 28 to stripper 30 along second tension zone 19. In one or more embodiments, the method includes applying no, almost no, or negligible tension to the base tape material 20 as the continuous tape 18 moves from source 16 (along the first tension zone) to tension breaker 28 and then to stripper 30 (along the second tension zone). In one or more embodiments, the method includes applying a tension to the carrier web 22 (at any point along the separating system 12) that is at least twice as great as the tension applied to the base tape material 20. Selecting a carrier web with a low elasticity can facilitate having the carrier web support a majority of the tension applied to the tape material.

[0061] In one or more embodiments, the method includes not applying any additional tension to the base tape material beyond the tension applied to the base tape material by applying tension to the carrier web 28. In such embodiments, applying tension to the carrier web as described above can stretch the carrier web, which generates some tension in the base tape material. In one or more exemplary embodiments, the method includes not applying any additional tension to the base tape material as the continuous tape material moves from the source 16 along the first tension zone 17 to the tension isolator 28. In one or more exemplary embodiments, the method includes not applying any additional tension to the base tape material as the continuous tape material moves from the tension isolator 28 along the second tension zone 19 to the peeler 30. In one or more embodiments, the method includes not applying any additional tension to the base tape material 20 as the continuous tape 18 moves from the source 16 (along the first tension zone) to the tension isolator 28 and then to the peeler 30 (along the second tension zone).

[0062] In one or more embodiments, the method for separating two materials (i.e., a substrate tape material and a carrier web) includes: feeding the continuous tape material into a tension breaker and applying a first tension to the carrier web; applying a second tension to the carrier web, the second tension being greater than the first tension; and orienting the carrier web to move in an unwinding direction and orienting the substrate tape material in a downstream process direction different from the unwinding direction. In one or more embodiments, applying the first tension includes applying little or no tension as disclosed herein. In one or more embodiments, applying the first tension includes applying little or no tension to the carrier web as the continuous tape material moves along the first tension zone from source 16 to tension breaker 28. In one or more embodiments, the second tension is about 2.5 PLI (446.45 g / cm) or less. For example, in one or more embodiments, the tension applied to the carrier web 22 is about 2.4 PLI (428.592 g / cm) or less, about 2.3 PLI (410.734 g / cm) or less, about 2.2 PLI (392.876 g / cm) or less, about 2.1 PLI (375.018 g / cm) or less, about 2 PLI (357.16 g / cm) or less, about 1.8 PLI ​​(321.444 g / cm) or less, about 1.6 PLI (285.728 g / cm) or less, about 1.5 PLI (267.87 g / cm) or less, about 1.4 PLI (250.012 g / cm) or less, about 1.2 PLI (214.296 g / cm) or less, or about 1 PLI (178.58 g / cm) or less. In one or more embodiments, the first tension is about 50% or less (e.g., about 45% or less, about 40% or less, about 35% or less, about 30% or less, or about 25% or less) of the second tension.

[0063] In one or more embodiments, the method includes at least partially sintering the substrate tape material (as described in more detail herein in connection with the sintering station) after separating the substrate tape material from the carrier web 22. In one or more embodiments, the method includes winding the substrate tape material 22 onto the intake reel 26 after separating the substrate tape material 20. In one or more embodiments, the method includes continuously maintaining tension on the carrier web 22 along a second tension zone until the carrier web is wound onto the intake reel.

[0064] Debinding Station As discussed above with respect to FIG. 3 , system 10 includes a heating station configured to remove binder material from substrate tape 20, which, in at least some embodiments, is actively heated independently of the sintering station. In other embodiments, such as those involving firing a bisque tape as disclosed herein, a heating station may not be present. Applicant has discovered that actively heating a station dedicated to binder removal using its own controllable heat source, independent of the heater in the sintering furnace, provides better control over the binder removal process and reduces the likelihood of combustion of volatiles in the substrate tape binder, which is particularly beneficial for wider substrate tapes (e.g., at least 5 mm, at least 10 mm, at least 30 mm, at least 50 mm). Other embodiments include passively heated binder removal stations, as disclosed herein, that use heat emitted from an adjacent sintering furnace.

[0065] According to one exemplary embodiment, as shown in Figure 3, the binder removal station 34 receives the substrate tape 20 from the separation station 12, and the substrate tape 20 then advances through the binder removal station 34. Referring now to Figure 9, a detailed view of the binder removal station 34 of the system 10 is shown and described in further detail.

[0066] As described above, the substrate tape 20 includes particles of inorganic material bound by a binder, such as an organic binder, as disclosed herein. The binder removal station 34 receives the substrate tape 20 and prepares it for sintering by chemically altering the binder and / or removing it from the substrate tape 20, leaving behind the particles of inorganic material, thereby forming a free-standing unbound tape 36, which can be moved in the process direction 14 toward a sintering station 38, as described in more detail below. According to one exemplary embodiment, at any one moment in time (i.e., a single moment in time), the substrate tape 20 simultaneously extends toward, into, through, within, adjacent to, and / or away from the station 34. Thus, it will be understood that the tape material processed in the system 10 simultaneously includes the substrate tape 20 continuously connected to the unbound tape 36 as the tape material passes through the binder removal station 34.

[0067] According to one exemplary embodiment, the binder of the substrate tape 20 may be a polymeric binder, which is chemically altered and / or removed from the substrate tape 20 by heating the binder to burn or carbonize it. According to one exemplary embodiment, the binder removal station 34 carbonizes or burns at least most of the organic binder by weight from the first portion of the substrate tape 20 without sintering the inorganic material particles, which can be measured by weighing the substrate tape before binder removal at station 34 and the inorganic material before forming the substrate tape, and then weighing the unbound tape 36 after operation of the binder removal station 34 and comparing the differences. If binder remnants, such as carbon, remain, Applicant believes that these remnants can be substantially removed by subsequent sintering at a higher temperature. In another possible embodiment, binders, such as those formed from materials selected to chemically react with another material (e.g., catalyst, gas) delivered to the substrate tape at the binder removal station before sintering, can be chemically removed. In yet another possible embodiment, the binder can be evaporated or vaporized and released as a gas from the green tape 20 at a pre-sintering station.

[0068] Continuing with reference to FIG. 9 , according to certain exemplary embodiments, the binder removal station 34 includes an active heater 5120 for carbonizing or burning off at least most of the organic binder from the substrate tape 20 when the substrate tape 20 contacts the binder removal station 34 to form the unbonded tape 36 (e.g., by reducing the weight of the portion of the substrate tape 20 that is not the inorganic material to be sintered by more than 50%, e.g., more than 70%, e.g., more than 90%; by reducing the overall weight of the substrate tape 20 by more than 30%, e.g., more than 50%). The active heater 5120 provides thermal energy to the substrate tape 20 to burn off the binder. In some embodiments, the heater 5120 is or includes an electronic heating element, such as an inductive or resistive heating element. In other embodiments, the heater 5120 is or includes a combustion heating element, such as a gas heating element. In still other embodiments, the heater 5120 is or includes a microwave and / or laser or other heating element. Such heating elements may also be used in sintering station 38 to heat to various temperatures as disclosed herein.

[0069] According to certain exemplary embodiments, the active heater 5120 of the binder removal station 34 includes heating zones, such as zones 5120A, 5120B, 5120C, and 5120D, that increase the amount of thermal energy received by the substrate tape 20 as it advances through the binder removal station 34. In some embodiments, the amount of thermal energy received by the substrate tape 20 increases in a nonlinear manner, such as initially increasing slowly as the binder breaks down and releases combustible gaseous byproducts, followed by a more rapid increase as the likelihood of igniting the substrate tape 20 decreases. This hot zone approach, and more particularly, the nonlinear approach, may be particularly useful for sintering tapes as disclosed herein that can move at a constant speed through a manufacturing line, such as system 10. According to certain exemplary embodiments, the temperature experienced by the substrate tape 20 in the binder removal station 34 may be at least 200° C., e.g., at least 250° C., and / or below the sintering temperature of the inorganic particles carried by the substrate tape 20, e.g., below 1200° C., e.g., below 900° C. In contemplated embodiments, for at least some materials disclosed herein, the binder removal station 34 may sinter, at least to some extent, the inorganic material of the tape, e.g., perhaps bonding individual particles together, thereby increasing the tensile strength of the tape.

[0070] According to certain exemplary embodiments, the binder removal station 34 blows and / or draws gas onto and / or beneath (e.g., above and below) the substrate tape 20 as it advances through the binder removal station 34. In some embodiments, a heater 5120 can provide a flow of hot air to transfer some or all of the thermal energy to the substrate tape 20, which can be delivered from a plenum through an array of nozzles through the wall or through the porous wall material. In other embodiments, the flow of gas is facilitated by a fan or pump adjacent to the binder removal station 34, such as fan 5122 shown in FIG. 9 . A tank of pressurized gas can be used as a source for providing the gas blown onto the tape. In some embodiments, the gas is air. In other embodiments, the gas is an inert gas, such as argon.

[0071] In some embodiments, the gas is blown and / or drawn against both the top and bottom of the substrate tape 20, while in other embodiments, the gas is directed against only the top or bottom. In some such embodiments, the substrate tape 20 is supported directly by and moves relative to a gas bearing and / or the underlying surface. For example, the substrate tape 20 may slide along and contact an underlying surface, such as a stainless steel surface. In some embodiments, the gas is heated to a temperature above room temperature, e.g., at least 100°C, before being blown or drawn onto the tape; Applicant has discovered that this temperature can help prevent thermal shock of the substrate tape 20, which can affect the properties of the resulting sintered material, providing increased strength or flatness, for example, by reducing the number of surface irregularities and stress concentration sites.

[0072] Actively blowing or drawing a gas, particularly air or a gas containing oxygen, onto the substrate tape 20 may not be intuitive to those skilled in the art, as oxygen might be expected to stimulate and promote ignition of the tape, which could distort the shape and / or impair the quality of the substrate tape 20 as it passes through station 34. However, applicant has discovered that blowing and / or drawing a gas, including air in some embodiments, onto the substrate tape 20 as it is transported through binder removal station 34 actually helps to prevent the tape from igniting. For example, applicant has discovered that while the binder is removed and / or carbonized by binder removal station 34 without ignition, if air is not blown onto the substrate tape 20, the tape will ignite when moving through station 34 at the same speed. Applicant believes that the risk of the base tape 20 catching fire can also be reduced and / or eliminated by: moving the base tape 20 more slowly through the binder removal station 34; spacing the high temperature zones 5120A, 5120B, 5120C, 5120D further apart; using flame retardants in the binder; and increasing ventilation in the binder removal station 34; and / or a combination of these techniques.

[0073] While gas can be actively blown and / or drawn onto the substrate tape 20 and / or the non-bonded tape 36, Applicant has discovered that, depending on how the gas flows, the non-bonded tape 36 may be particularly susceptible to damage from vibration and / or out-of-plane bending. Thus, in some embodiments, the gas flowing through the binder removal station 34 is and / or includes a laminar flow. The air flow may be diffused and / or may not be directed toward the non-bonded tape 36. In some embodiments, a gas source or motivator (e.g., a fan, pump, pressurized supply) delivers at least 1 liter / minute of gas through the binder removal station 34, for example, through passageway 5128 (see FIG. 10 ).

[0074] According to some embodiments, the substrate tape 20 advances horizontally, rather than vertically, through the binder removal station 34. Orienting the tape horizontally can help control airflow through the binder removal station 34, such as by reducing the "chimney effect" (where hot gases rise through the binder removal station 34, drawing in too much air and causing the unbonded tape 36 to vibrate). In other contemplated embodiments, the air pump, fan, and ambient air conditions (e.g., high temperature) offset and / or control the chimney effect without horizontally orienting the substrate tape 20 through the binder removal station 34.

[0075] According to one exemplary embodiment, the non-bonded tape 36 is under positive longitudinal tension as the substrate tape 20 advances through station 34. The tension in the substrate tape 20 can help maintain the substrate tape 20 in a flat orientation, such as when the substrate tape 20 moves into another station in the manufacturing system, such as sintering station 38, for further processing. Without a binder (e.g., following binder removal in station 34), the non-bonded tape 36 can be weaker than the substrate tape material 20, e.g., having a lower ultimate tensile strength, such as less than half, or less than one-quarter, etc. According to one exemplary embodiment, the longitudinal tension (i.e., tensile stress) of the non-bonded tape 36 is 0.015 psi per mm cross-section. 2 Applicant has determined that the substrate tape 20 is significantly more flexible than the unbonded tape 36, such that the minimum bend radius at which the substrate tape 20 will not break is less than half (e.g., less than 1 / 4, less than 1 / 8) of the minimum bend radius of the unbonded tape 36, as measured by ASTM standards (see E290). In this ASTM standard, the bend radius is the smallest inside radius at which portions of the substrate tape 20 can be bent around a cylinder without breaking.

[0076] In at least some embodiments, after processing through the binder removal station 34, the unbonded tape 36 moves into a sintering station 38 (described in detail below) which at least partially sinters the inorganic material of the unbonded tape 36 to form a sintered tape 40. Thus, for continuous processing, at any given moment, the green tape 20 is continuously connected to the sintered tape 40 by the unbonded tape 36.

[0077] In some such embodiments, the binder removal station 34 is in close proximity to the sintering station 38, with a distance therebetween of less than 10 meters (e.g., less than 10 mm, less than 2.5 cm, less than 5 cm, less than 10 cm, less than 25 cm, less than 100 cm, less than 5 meters, etc., between the exit opening of the binder removal station 34 and the entrance opening 106 (see FIG. 12 ) of the sintering station 38), thereby reducing the thermal shock that the unbonded tape 36 may experience in the gap between stations 34 and 38. This thermal shock may affect the properties of the resulting sintered material, providing, for example, increased strength or flatness due to fewer surface irregularities and stress concentration sites. In contemplated embodiments, the binder removal station 34 is directly adjacent to and / or under a common housing with the sintering station 38, although in at least some such embodiments, intermediate vents remove fumes or other by-products of binder removal.

[0078] 10 , the binder removal station 34 includes a wall 5126 defining a passageway 5128 having an entrance opening 5130 and an exit opening 5132 at opposite ends of the passageway 5128. The passageway has a length L between the entrance opening 5130 and the exit opening 5132, which in some embodiments is at least 5 cm, e.g., at least 10 cm, and / or no more than 10 m. According to certain exemplary embodiments, the exit opening 5132 and / or the entrance opening 5130 are elongated, e.g., have a height H and a width perpendicular to the height H, where the height H is less than half the width W, e.g., less than 1 / 5 of the width W, e.g., less than 1 / 10 of the width W. In some such embodiments, the height H is less than 5 cm, e.g., less than 2 cm, e.g., less than 1 cm, and / or is at least greater than the thickness of the substrate tape 20 to be processed, at least greater than the thickness of the substrate tapes disclosed herein, e.g., at least 20 μm. Applicant has discovered that having one or more narrow openings improves the performance of binder removal station 34 by limiting the circulation of gas (e.g., ambient airflow) at entrance opening 5130 and exit opening 5132. In some embodiments, path 5128 is straight, while in other embodiments, the path is gently curved, for example, having a radius of curvature greater than 1 m, in which case the curvature of the tape and the corresponding curvature can assist in shaping and flattening the tape.

[0079] 11 , a method 5210 of processing tape includes a step 5212 of advancing a tape through a manufacturing system (e.g., a binder removal station 34 disclosed herein or other manufacturing system), for example, where the tape includes a first portion (e.g., green tape 20) having grains of inorganic material bound by a binder. The method further includes a step 5214 of preparing the tape for sintering by forming a second portion of the tape (e.g., unbound tape 36) at a station in the manufacturing system by chemically altering the binder and / or removing the binder from the first portion of the tape, leaving the grains of inorganic material behind, thereby forming a second portion of the tape.

[0080] In some such embodiments, preparing the tape for sintering step 5214 further includes carbonizing or burning off at least most of the binder from the first portion of the tape (e.g., as described above), with or without simultaneously sintering the grains of inorganic material. In some embodiments, the station of the manufacturing system is a first station, and the method of processing 5210 further includes receiving a second portion of the tape at a second station 5218, and at least partially and / or further sintering the inorganic material of the second portion of the tape at the second station 5220 to form a third portion of the tape.

[0081] In some embodiments, the method of processing 5210 further includes applying positive tension to the second portion of the tape during the tape advancing step 5212. In some such embodiments, applying positive tension means that the longitudinal tension (i.e., tensile stress) of the second portion of the tape is greater than or equal to 1 mm 2 in cross section. 2 In some embodiments, method of processing 5210 further includes blowing and / or drawing a gas onto the tape during step 5214 of preparing the tape for sintering. In some embodiments, step 5212 of advancing the tape further includes advancing the tape horizontally through the station and / or supporting the tape directly by a gas bearing and / or the surface of the underlying layer and moving the tape against this surface and / or against opening 5128.

[0082] Binder removal example Applicant used a binder burnout furnace similar to binder removal station 34 to remove the binder from the green tape prior to sintering. By way of example, the green tape was tape-cast zirconia ceramic granules loaded with a polymer binder, forming a ribbon approximately 42 mm wide and approximately 25 μm thick. The green tape was fed at 20 inches (50.8 cm) per minute through a horizontal, six-high-temperature zone binder burnout furnace. The furnace was set at 325°C at the inlet and 475°C at the outlet, with the other four high-temperature zones increasing in temperature in increments of 0 to 25°C. An airflow of approximately 7.5 liters / minute between 0 and 250°C was also provided. This airflow was split between both sides of the binder burnout furnace. The furnace was 36 inches (91.44 cm) long with 18-inch (45.72 cm) high-temperature zones.

[0083] Sintering Station 12-20, the sintering station 38 is shown and described in further detail. Generally, after the binder material is removed from the substrate tape 20 in the binder removal station 34, the unbonded tape 36 moves into the sintering station 38.

[0084] In at least one specific embodiment, the sintering station 38 includes a sintering furnace 100. The sintering furnace 100 includes an insulated housing 102. Generally, the insulated housing 102 includes a plurality of interior walls that define a channel 104 extending through the sintering furnace 100 between an inlet, shown as an inlet opening 106, and an outlet, shown as an outlet opening 108. The binder removal station 34 is positioned adjacent to the inlet opening 106, such that the green tape material 20 passes through the binder removal station 34 as described above to produce unbonded tape material 36. The unbonded tape material 36 moves into the inlet opening 106 and through the channel 104. While in the channel 104, heat generated by a heater (described in more detail below; discussed above with respect to various types of heating elements) causes sintering of the unbonded tape 36 to form a sintered tape 40, which exits through the outlet opening 108 for further processing or incorporation, as shown in FIG. 3 . Depending on the temperature profile to which the unbonded tape 36 is exposed during sintering, the tape 40 may be fully sintered or partially sintered upon exiting the sintering furnace 100. Regardless of whether the tape 40 is partially sintered or fully sintered, the porosity of the tape 40 will be less than the porosity of the base tape 20 due to the sintering that occurs within the furnace 100. Similarly, in some embodiments, the width of the tape 40 is less than the width of the base tape 20. In some such embodiments, and in still other embodiments, shrinkage of the unbonded tape 36 may be controlled during sintering such that the thickness, width, and / or length of the tape 40 is less than the thickness of the base tape 20.

[0085] As can be seen in FIG. 12 , and in contrast to typical sintering systems based on individual pieces, the unbonded tape 36 is a continuous length of material that extends completely through the furnace 100. In this configuration, a single continuous length of unbonded tape 36 enters the inlet 106, extends through the channel 104, and exits through the outlet 108. As will be appreciated, because the unbonded tape 36 is continuous through the furnace 100, its left edge, its right edge, and its centerline (e.g., a longitudinal line parallel to and equidistant from the left and right edges) also extend, or may extend, the entire distance through the furnace 100 between the inlet 106 and the outlet 108. For reference, FIG. 14 shows these edges after exiting the sintering furnace 100 as edges 130 and 132. This relationship between the continuous tape 36 and the furnace 100 is believed to be unique to the roll-to-roll sintering process described herein and differs from the physical configuration of tunnel kiln processes for sintering, in which individual pieces of material move through the furnace supported by setter boards that move through the furnace with the pieces being sintered. For example, in some embodiments, the tape slides against and / or along one or more surfaces (e.g., lower surface 126) through the channel 104 of the furnace 100 and is not carried by a setter or conveyor, thereby reducing wear on the setter, static or dynamic friction, and adhesion-related bonding and adhesion of the tape to the tape.

[0086] As mentioned above, Applicant has discovered that a high level of horizontality of the channels 104 and / or the unbonded tape 36 within the channels 104 reduces the effect of turbulent airflow on the tape 36 during sintering. As shown in FIG. 12 , the channels 104, the inlets 106, and the outlets 108 lie in a generally horizontal plane. In particular embodiments, the path defined by the central axes of the channels 104, the inlets 106, and the outlets 108 defines a generally horizontal plane and / or a gentle curve or curve (e.g., having a radius of curvature of at least 1 m). Similarly, in such embodiments, the unbonded tape 36 may also lie in a generally horizontal plane and / or a gentle curve or curve within the channels 104 (e.g., the upper surface 124 and / or the lower surface 126 of the tape 36 shown in FIG. 13 lie in a generally horizontal plane). As used herein, the generally horizontal plane defined by the channels 104, the inlets 106, and the outlets 108 of the tape 36 forms an angle of 10° or less with respect to a horizontal reference plane. In other specific embodiments, the channels 104, inlets 106 and outlets 108, and / or tape 36 within the channels 104 lie in a more horizontal plane, e.g., a plane that forms an angle of 3° or less with respect to a horizontal reference plane, more specifically, a plane that is at an angle of 1° or less with respect to a horizontal reference plane. In other embodiments, if the channels 104 are not so oriented, the corresponding sintered tape may have indicia associated with a "chimney effect" or irregular heating (e.g., undulating surface hills or ridges), for example, if the airflow through the channels 104 is turbulent.

[0087] To further control or limit the turbulent airflow to which the tape material of system 10 is exposed while passing through system 10, binder removal station 34 may be positioned relative to sintering station 38 in a manner that maintains the tape material (e.g., green tape material 20 in the binder removal station, and unbonded tape material 36 in the sintering station) in a generally horizontal position as tapes 20 and 36 pass through binder removal station 34 and sintering station 38. In such an embodiment, similar to the horizontal positioning of sintering channel 104, binder removal station 34 is also oriented or can be oriented in a generally horizontal position, for example, where openings 116, 118 are aligned to form a line therebetween that is within 10 degrees of the horizontal.

[0088] In such an embodiment, the binder removal station 34 includes a binder burnout furnace 110. The binder burnout furnace 110 includes an insulated housing 112. Generally, the insulated housing 112 includes a plurality of interior walls that define a channel 114 that extends through the binder burnout furnace 110 between an entrance opening 116 and an exit opening 118.

[0089] Referring to the binder burnout furnace 110, as shown in FIG. 12 , the channels 114, the inlets 116, and the outlets 118 lie in a generally horizontal plane. In a specific embodiment, the paths defined by the central axes of the channels 114, the inlets 116, and the outlets 118 define a generally horizontal plane. Similarly, in such an embodiment, the substrate tape 20 may also lie in a generally horizontal plane within the channels 114. As used herein, the generally horizontal plane of the substrate tape 20 and of the channels 114, the inlet openings 116, and the outlet openings 118 is one that forms an angle of 10° or less with respect to a horizontal reference plane. In other specific embodiments, the channels 114, the inlet openings 116, and the outlet openings 118, and / or the substrate tape 20 within the channels 114 lie in a plane that is more horizontal, for example, forms an angle of 3° or less with respect to the horizontal reference plane, and more specifically, is at an angle of 1° or less with respect to the horizontal reference plane. In still other embodiments, these features may not be aligned horizontally in this manner.

[0090] In addition to maintaining the horizontality of the substrate tape 20 and the unbonded tape 36 within the binder burnout furnace 110 and the sintering furnace 100, respectively, the binder burnout furnace 110 (also referred to as a binder removal station) and the sintering furnace 100 are aligned with one another so that the unbonded tape 36 maintains a horizontal position as it transitions from the binder burnout furnace 110 to the sintering furnace 100. Applicant has discovered that at this transition point, the unbonded tape 36 is particularly susceptible to deformation or breakage due to various forces, such as those caused by turbulent airflow. This is because, once most of the organic binder has been removed, the unsintered inorganic particles of the unbonded tape 36 are held together by relatively weak forces (e.g., van der Waals forces, electrostatic interactions, small amounts of residual organic binder, frictional interactions / engagements between adjacent particles, low levels of inorganic matter carried in the binder, plasticizers, liquid vehicles, possibly some inter-particle bonding, etc.), and therefore even relatively weak forces such as those caused by turbulent airflow interacting with the unbonded tape 36 can cause deformation or breakage.

[0091] Thus, as shown in FIG. 12 , the channel 114 of the binder burnout furnace 110 is vertically aligned with the channel 104 of the sintering furnace 100 to limit turbulent airflow. Following the tape path through the sintering furnace 100 and binder burnout furnace 110, the green tape 20 moves horizontally from the input roll (shown in FIG. 3 ) to the binder burnout furnace entrance 116, through the binder burnout furnace channel 114, and out the binder burnout furnace exit 118. While in the channel 114, heat generated by the heater of the furnace 110 chemically alters and / or removes at least a portion of the organic binder material of the green tape 20, which is referred to as "burnout." Furthermore, the relative positioning of the binder burnout furnace 110 and the sintering furnace 100 is such that all of the unbonded tape 36 moves from the binder burnout furnace 110 into the sintering furnace 100 while remaining in the horizontal or generally horizontal position described above. Thus, due to the vertical alignment between channel 104 and channel 114, in at least some embodiments, the unbonded tape 36 remains in approximately the same horizontal plane (i.e., does not displace up or down between furnace 110 and furnace 100) as the tape material passes through both furnaces 100 and 110.

[0092] Applicant has determined that the benefits of horizontal binder removal and / or horizontal sintering become even more significant as the width of the tape material increases, since wider tape material is more susceptible to deformation due to turbulent airflow. Applicant therefore believes that the horizontal configuration of the sintering furnace 100 and / or binder burnout furnace 110 allows for the production of wider and / or longer sintered tape material without significant deformation or breakage, which was previously thought to be unattainable using conventional systems.

[0093] 13 and 14, in addition to horizontal positioning of the binder burnout furnace 110, the sintering furnace 100, and the tape material therein (e.g., the green tape 20 and the unbonded tape 36), Applicant has also discovered that turbulent airflow can be limited by providing the sintering channel 104 with a relatively small height dimension (which corresponds to a relatively small clearance for the unbonded tape 36). Applicant has discovered that turbulent airflow, which can be generated by extremely hot air within the channel 104, can be limited by reducing the volume of the area where thermal gradients can occur and which can cause air movement.

[0094] 13 and 12, channel 104 is at least partially defined by a horizontal, generally upwardly facing surface 120, which defines at least a portion of the lower surface of channel 104. Similarly, channel 104 is also at least partially defined by a horizontal, generally downwardly facing surface 122, which defines at least a portion of the upper surface of channel 104. A first gap, designated G1, is the vertical distance between upwardly facing surface 120 and downwardly facing surface 122, and G2 is the vertical distance or clearance between downwardly facing surface 122 and an upper surface 124 of non-bonding tape 36.

[0095] As noted above, in various embodiments, G1 and G2 are relatively small so as to limit turbulent airflow, although G1 and G2 should generally be large enough to allow for various processing steps (e.g., threading of channel 104). In various embodiments, G2 is less than 0.5 inches (less than 12.7 mm), specifically less than 0.375 inches (less than 9.5 mm), and more specifically 0.25 inches (approximately 6.35 mm). As will be appreciated, G1 is approximately equal to G2 plus the thickness T1 of the unbonded tape 36. Thus, in various embodiments, T1 is relatively small, e.g., between 3 micrometers and 1 millimeter, so that G1 is less than 1 inch (less than 25.4 mm), specifically less than 0.75 inches (less than 19 mm), and may be less than 0.5 inches (less than 12.7 mm) for thin tape materials and less than 0.375 inches (less than 9.5 mm) for ultra-thin tape materials.

[0096] 14 shows the outlet 108 of the sintering furnace 100 and illustrates the small clearance G2 for the tape 40 according to an example embodiment. In various embodiments, G1 and G2 may represent the maximum gap distance between the associated surfaces, while in other embodiments, G1 and G2 may represent the average gap distance between the associated surfaces measured along the length of the channel 104.

[0097] In specific embodiments, surfaces 120 and / or 122 are also generally horizontal surfaces (as described above) extending between inlet 106 and outlet 108 of furnace 100. Thus, in such embodiments, surfaces 120 and 122 define a generally horizontal channel 104. In some specific embodiments, surfaces 120 and / or 122 may be flat, planar, horizontal surfaces extending the entire distance between inlet 106 and outlet 108 of furnace 100. In other specific embodiments, surfaces 120 and / or 122 may be gradually curved or contoured, as described above, such as may be the case for a binder removal station. In specific embodiments, surfaces 120 and / or 122 are generally horizontal such that they form an angle of less than 10°, specifically less than 3°, and even more specifically less than 1°, with respect to a horizontal reference plane.

[0098] 13 , the lower surface 126 of the non-bonded tape 36 contacts the upwardly facing surface 120, causing the lower surface 126 of the non-bonded tape 36 to slide along or against the upwardly facing surface 120 as the non-bonded tape 36 advances through the furnace 100. In certain embodiments, the sliding contact between the lower surface 126 and the upwardly facing surface 120 during sintering produces or can produce various longitudinal features (e.g., longitudinally extending marks, troughs, ridges, etc.) formed on the lower surface 126 but not on the upper surface 124. Thus, in specific embodiments, the surface features on the lower surface 126 are different from the surface features on the upper surface 124, which do not contact the opposing surface during sintering. Notably, this sliding contact differs significantly from the configuration in some firing processes, such as a tunnel kiln process, in which the ceramic material rests on a setter board and both move through a sintering furnace. In a specific embodiment, surfaces 120 and 122 are or include alumina, such as the interior surfaces of an alumina tube that defines channel 104 .

[0099] In addition to the positional and airflow control configurations described above, Applicant has also discovered that control of the temperature profile through the furnace 100 to which the unbonded tape 36 is exposed is important to limit deformation or breakage of the tape, which can occur if the temperature rises too quickly (e.g., if the sintering rate is too fast or over too short a distance of the tape). Referring generally to FIG. 15, the furnace 100 may include multiple independently controlled heating elements 140 positioned to deliver heat to the channels 104 to cause sintering of the unbonded tape 36 as it passes through the furnace 100. While maximum and minimum sintering temperatures will vary based at least in part on the type of inorganic material particles carried by the tape 36, generally, the heating elements 140 are configured to generate a temperature of at least 500° along at least a portion of the channels 104. In some embodiments, for example, for sintering ThO2 (thoria) and / or TiO2 (titania), the channel 104 may be heated to a maximum temperature of over 3100° C. There are some materials, e.g., carbides, tungsten, that have melting points above 3200° C., and in some such embodiments, the temperature range generated by the heater 140 is from 500° C. to higher temperatures, e.g., 3500° C. or 3600° C. In a specific embodiment, the heating element 140 may be a U-shaped molybdenum disilicide heating element and / or other heating elements disclosed herein.

[0100] Generally, each heating element 140 may be under the control of a control system 142, which is configured (e.g., physically arranged, programmed, etc.) to independently control the individual heating elements 140 of the furnace 100 to generate a temperature profile along the length of the channel 104 to provide a desired level of sintering in the sintered tape 40 while limiting deformation during sintering. In some embodiments, the control system 142 may be in communication with one or more temperature sensors 144 that detect the temperature in the channel 104. In such embodiments, the control system 142 may control the heating elements 140 to maintain a desired temperature profile during the continuous sintering of the continuous unbonded tape 36 based on input signals received from the sensors 144. In some embodiments, the control system 142 may also receive input signals indicative of tape movement speed, position, contraction, and tension, and control the temperature and / or movement speed based on these signals or other signals that may be related to these or other tape properties.

[0101] As demonstrated in connection with the sintering furnace example described below, applicants have discovered that application of a sintering temperature profile along the length of the channel 104 is, or can be, important for maintaining a low or controlled level of deformation of the tape material during sintering. In particular, applicants have discovered that if the unbonded tape 36 is exposed to too much temperature increase during sintering (e.g., if the temperature profile slope is too steep), unacceptably high levels of stress will or may form in the tape 36 as the material sinters and shrinks, resulting in out-of-plane deformation of the tape 36, such as that shown in FIG. 2. In particular, applicants have discovered that by controlling the stress at the edges 130 and 132 and / or along the centerline of the tape 36 during sintering, they can control deformation of the tape 36 during sintering. Similar potentially detrimental effects on the tape 36 can occur if the transition from an elevated temperature portion of the system 10 to a room temperature portion of the system 10 (e.g., upon exiting the furnace 100) is made too abruptly. That said, the techniques of the present application can also be used to sinter tapes without such temperature control or profiling, in which case the resulting novel tapes or other sintered articles may have characteristic deformations or other defects as described above.

[0102] 16 and 17, temperature profiles 160 and 170 generated by the heating element 140 along the length of the sintering channel 104 are shown, according to an exemplary embodiment. Referring to FIG. 16, the temperature profile 160 shows that the temperature within the channel 104 generally increases in the process direction 14 along the length of the channel 104. The profile 160 includes at least three sections: a first section 162 representing the temperature within the region of the channel 104 adjacent to the entrance opening 106; a second section 164 representing the temperature along a majority (e.g., at least 50%, at least 75%, etc.) of the length of the channel 104; and a third section 166 representing the temperature within the region of the channel 104 adjacent to the exit opening 108.

[0103] As shown in FIG. 16 , the average slope of the first section 162 is greater than the average slope of the second section 164, indicating a relatively rapid temperature increase within the channel 104 adjacent the entrance opening 106. The average slope of the second section 164 is relatively lower (and less than the average slope of the first section 162). The lower average slope of the second section 164 represents the gradual increase in temperature experienced by the tape 36 as it moves along most of the length of the channel 104. As described below, this gradual increase is selected to maintain stress within the tape 36 below a predetermined threshold that keeps deformation below a desired level. The average slope of the third section 166 is a negative slope, representing a cooling section within the channel 104 adjacent the exit opening 108, which limits the thermal shock experienced by the tape 36 upon exiting the furnace 100.

[0104] In various embodiments, the gradual temperature increase represented by the small slope of section 164 can be achieved by controlling the rate of temperature increase along the length of channel 104. In various embodiments, the length of channel 104, as represented by the x-axis of the plot in Figure 16, can be relatively large, such as at least 1 meter, at least 50 inches (127 cm), at least 60 inches (152.4 cm), or more. In the particular sintering furnace modeled and illustrated in Figure 16, the heated channel 104 is 64 inches (162.56 cm).

[0105] In various embodiments, profile 160 is shaped to maintain compressive stresses within tape 36 during sintering at an acceptably low level, thereby avoiding undesirable deformation. Applicant has discovered that tape deformation, if not controlled as described herein, can be a challenge, particularly with wide tape materials and high-throughput sintering systems. Wider tapes are particularly susceptible to this type of deformation, and furthermore, widthwise deformation can make or even render winding onto a take-up reel difficult or impossible. That said, aspects of the disclosed techniques (e.g., carrier separation, tension control, binder removal, etc.) may be implemented and used to produce novel materials and products without the temperature profile described above, for example, where the resulting product has a relatively narrow width and / or where the resulting product has defects or deformations characteristic of such processing.

[0106] Thus, in various embodiments, the profile 160 is shaped so that the compressive stress at the left edge 130 and / or right edge 132 of the unbonded tape 36 during sintering remains below an edge stress threshold, and the compressive stress at the centerline of the unbonded tape 36 during sintering remains below a centerline stress threshold. Generally, the edge and centerline stress thresholds are defined as the compressive stresses above which the unbonded tape 36 will undergo out-of-plane (length-width plane) deformation of more than 1 mm during sintering. Applicant has discovered that, for at least some materials and tape widths, maintaining the edge and centerline compressive stresses below a threshold of 100 MPa, specifically 75 MPa, and more specifically 60 MPa, can limit out-of-plane deformation to less than 1 mm during sintering. In one specific embodiment, Applicant has discovered that for at least some materials and tape widths, out-of-plane deformation during sintering can be limited to less than 1 mm by maintaining the centerline compressive stress below a threshold of 100 MPa, specifically 75 MPa, more specifically 60 MPa, and by maintaining the edge stress below a threshold of 300 MPa, specifically 250 MPa, more specifically 200 MPa.

[0107] In one particular embodiment, controlling the gradient of sections 162 and 166 can provide particularly low tape stresses at the entrance to and exit from furnace 100. In one such embodiment, control system 142 is configured to control the temperature profile within sections 162 and 166 in combination with controlling the speed of the tape through furnace 100. In such an embodiment, this combination of controlling the temperature within sections 162 and 166 and speed control results in uniform sintering shrinkage (sintering distortion), and therefore low stress and small deformation, within tape 36 during sintering.

[0108] Referring to FIG. 17 , another exemplary temperature profile 170 is shown projected along a diagram of the channel 104. As shown, the profile 170 shows a rise to a maximum temperature in a zone 172 that spans approximately at least 75% of the length of the channel 104. In certain embodiments, the sintering furnace 100 can be made of a highly thermally conductive material (e.g., steel or a highly conductive ceramic) to reduce temperature gradients across the web (tape / sheet) width. As shown in FIG. 17 , there is little or no temperature variation across the width. As generally understood, the temperature profile for a particular sintering system will be based on the type of material, inorganic particle size, particle density, particle size distribution, porosity, pore size, pore size distribution, sintering atmosphere, stress thresholds / acceptable deformation for the part as described above, length of the channel 104, throughput rate, etc., as well as the desired outcome.

[0109] Referring to FIG. 18 , another embodiment of a sintering station 38 is shown, according to an example embodiment. In this embodiment, the sintering station 38 includes two furnaces 180 and 182 positioned in series with one another. In general, the furnaces 180 and 182 are substantially identical to the furnace 100 described above, except that, in at least some embodiments, the temperature profile in the furnace 180 differs from the temperature profile in the furnace 182. In this configuration, the unbonded tape 36 enters the inlet 106 of the furnace 180. Within the furnace 180, the unbonded tape 36 is partially sintered to form a partially sintered tape 184, which exits the furnace 180 through the outlet 108. The partially sintered tape 184 then enters the second furnace 182 through the inlet 106, where further sintering occurs along the length of the channel 104 of the furnace 182, causing the sintered tape 40 to exit the furnace 182 through the outlet 108 for reeling as described above.

[0110] In various embodiments, each furnace 180 and 182 includes multiple independently controllable heating elements, which allows for different and independent temperature profiles to be created within each furnace 180 and 182. In some embodiments, utilizing two thermally isolated furnaces, e.g., furnaces 180 and 182, can provide more precise control of the temperature profile to which the tape material is exposed during sintering than a single long furnace having a channel length equal to the combined channel length of furnace 180 and furnace 182. In other contemplated embodiments, the tape can be moved back through the same furnace, but along a different path, and / or exposed to a different temperature profile, for further sintering.

[0111] Furthermore, in some embodiments, it may be desirable to apply different tensions between furnace 180 and furnace 182. In such embodiments, a tension control system 186 is positioned along the sintering path defined by channels 104 of furnaces 180 and 182. In a specific embodiment, tension control system 186 is positioned between furnaces 180 and 182 and applies tension to partially sintered tape 184 such that the tension of tape 184 in second furnace 182 is greater than the tension of unbonded tape 36 in furnace 180. In various embodiments, increasing the tension in the second sintering furnace may be desirable to provide improved flatness or reduced distortion during final or subsequent sintering in furnace 182. Furthermore, this increased tension may be suitable for application to partially sintered tape 184 because partial sintering increases the tensile strength of tape 184 compared to the relatively low tensile strength of unbonded tape 36 in furnace 180.

[0112] 19, expected temperature profiles within furnaces 180 and 182 are shown, according to an example embodiment. As shown in FIG. 19, temperature profile 190 is generated by controlling the heating elements of furnace 180, and temperature profile 192 is generated by controlling the heating elements of furnace 182. As described below, both profiles 190 and 192 have gradual temperature increases similar to the gradual temperature increases of temperature profile 160 described above, which generate the same low stresses. However, profile 192 is located above profile 190 (e.g., has a higher average temperature) which causes a higher level of sintering (e.g., more shrinkage, less porosity) to occur as partially sintered tape 184 passes through furnace 182.

[0113] Referring to FIG. 20, a high-throughput sintering system 200 is shown according to an example embodiment. Generally, the system 200 includes two parallel systems 10, each sintering a tape material. The system 200 can be operated to increase the output of a single type of sintered tape material, similar to the configuration of FIG. 18. Alternatively, each system 10 of the system 200 can output a different sintered tape material. In various embodiments, the system 200 can include three, four, five, etc. parallel systems 10 to further increase the output of sintered tape material.

[0114] Sintering Station Examples and Models 21-28, various sintering tests and models are described that demonstrate the sintering relationships described herein, such as the relationship between temperature profile and shrinkage, the relationship between temperature profile and stress in the tape material, the relationship between stress and tape deformation, and the relationship between tape width and risk of sintering deformation.

[0115] Physical sintering test example 1 In one example, a horizontal furnace with an actively controlled, multi-zone binder burnout furnace was tested. In this test, a 42 mm wide, approximately 25 micrometer thick tape-cast "green" zirconia ceramic ribbon (ceramic loaded with a polymer binder) was fed at 20 inches (50.8 cm) per minute through a horizontal apparatus with a multi-zone binder burnout furnace (similar to furnace 38 and binder removal station 34 described above). The binder burnout furnace was set at 325°C at the inlet, with four central hot zones stepping up the temperature in 0-25°C increments to 475°C at the outlet. An airflow of approximately 7.5 liters / minute was also provided, ranging in temperature from approximately 0 to approximately 250°C. This airflow was split between the two sides of the burnout furnace. The sintering furnace was 36 inches (91.44 cm) long with an 18-inch (45.72 cm) long hot zone. The tape was transported through the sintering furnace by sliding it over an alumina "D" tube; the tension was 20 grams and the furnace was set at 1225°C. The resulting 10-20 ft (3.048-6.096 m) of sintered zirconia tape was wound onto a 3 inch (7.62 cm) diameter take-up reel. The sintering shrinkage across the width was approximately 12%.

[0116] Sintering model 1 Referring to Figures 21 and 22, the sintering shrinkage of zirconia is shown as a function of time and temperature. Figure 21 shows a graph of the sintering shrinkage of zirconia tape at various temperatures and times at temperature. Figure 22 shows a graph of the curve generated by a mathematical function of the sintering shrinkage of zirconia tape at various temperatures and times at temperature.

[0117] To generate the data points shown in Figure 21, tape-cast "green" zirconia ceramic ribbons (ceramics loaded with a polymer binder) 15 mm wide and approximately 25 micrometers thick were "biscuit" fired at 8 inches (20.32 cm) per minute to 1200°C in the apparatus described above in "Physical Sintering Test Example 1." The prefired tapes thus produced were fired in a narrow hot-zone furnace at temperatures of 1250°C, 1300°C, 1350°C, 1400°C, 1450°C, and 1500°C for 30 seconds, 1 minute, 2 minutes, 3 minutes, and 5 minutes. Sintering shrinkage was measured, and these data are shown in Figure 21.

[0118] From this sintering data, a mathematical curve was fitted that describes the sintering shrinkage as a function of temperature and time and extrapolated to temperatures lower and intermediate than those actually tested. This curve fit and extrapolation is shown in Figure 22. Based on the tests and curve fits shown in Figures 21 and 22, the relationship between sintering shrinkage, sintering time, and temperature for zirconia was determined. Applicants believe that this information can be used to derive a sintering temperature profile for zirconia to achieve the desired shrinkage and reduce stress below the deformation thresholds mentioned above.

[0119] In one specific embodiment, this data was used to model a 64-inch (162.56 cm) sintering furnace and temperature profile shown in Figure 16. As shown in Figure 16, the thermal gradient / profile 160 started at 1250°C and ended at 1450°C. The modeled temperatures increased from 1250°C to 1300°C from 0 inches (0 cm) to 8 inches (20.32 cm) into the furnace, increased from 1300°C to 1312.5°C from 8 inches (20.32 cm) to 16 inches (40.64 cm), increased from 1312.5°C to 1325°C from 16 inches (40.64 cm) to 24 inches (60.96 cm), maintained at 1325°C from 24 inches (60.96 cm) to 32 inches (81.28 cm), and increased from 32 inches (81.28 cm) to 1450°C. The temperature rose from 1325°C to 1375°C from 40 inches (101.6 cm), from 1375°C to 1400°C from 40 inches (101.6 cm) to 48 inches (121.92 cm), from 1400°C to 1450°C from 48 inches (121.92 cm) to 56 inches (142.24 cm), maintained at 1450°C from 56 inches (142.24 cm) to 64 inches (162.56 cm), and then cooled to below 1000°C from 64 inches (162.56 cm) onwards.

[0120] Shrinkage was modeled as a function of tape transport speed. As shown in Figure 16, the model indicated that a relatively high transport speed of 20 inches (50.8 cm) per minute (ipm) resulted in more uniform sintering shrinkage across the length of the hot zone. Thus, this modeling demonstrates that uniform shrinkage over a relatively long length is desirable because the shorter the distance over which sintering distortion / shrinkage occurs, the greater the stress in the tape and the greater the tendency for fracture and out-of-plane plastic deformation.

[0121] Sintering Model 2 23 and 16, sintering stresses were modeled using finite element analysis (FEA) and closed-form (CF) solutions. As the width of the sintered tape increases, as demonstrated in FIGS. 23 and 24, ultimate sintering stresses of greater than -1000 MPa are calculated for a 100 mm wide stationary tape (single hot zone), a 100 mm wide tape with only two hot zones, and tapes transported at 8 in. (20.32 cm) and 16 in. (40.64 cm) per minute. In contrast, when nine hot zones were used in two sintering passes (which is equivalent to 18 hot zones in a single pass), edge stresses of less than approximately -200 MPa were modeled for a 150 mm wide sheet. In the single and four-high-temperature zone tests, each high-temperature zone was modeled to have a length of 450 mm (18 inches) with the furnace being 900 mm (36 inches); therefore, in these two modeling examples, additional high-temperature zones equate to longer high-temperature zones. For example, one zone / two passes of high-temperature zones generally equates to one high-temperature zone with a total length of 900 mm (36 inches). However, nine zones / two passes of high-temperature zones equates to one high-temperature zone with a total length of 3660 mm (144 inches). Thus, Figures 23 and 24 demonstrate that by controlling the number of high-temperature zones (e.g., total length of the sintering high-temperature zones), the temperature profile to which the tape is exposed, and the speed of the tape travel through the high-temperature zones, increasingly wider tapes (e.g., greater than 50 mm, 100 mm, 150 mm, 200 mm, 250 mm, etc.) can be accommodated and sintering stresses can be maintained at a low enough level to avoid the creation of deformations, creases, or breaks.

[0122] Sintering Model 3 Figures 25 and 26 show a model of an unsintered zirconia tape (i.e., a partially sintered tape) passing twice through a single high-temperature zone with a steep temperature gradient. The high-temperature zone was set to 1250°C for the first pass, followed by 1400°C for the second pass. Tape transport speeds of 8 in. (20.32 cm) and 16 in. (40.64 cm) per minute were input. The tapes were modeled to be 20 micrometers thick and 15 mm and 40 mm wide. Figure 25 shows the shrinkage through the high-temperature zone, and Figure 26 shows that rapid sintering distortion generates significant compressive stresses in the tape of over 90 MPa (for a 40 mm wide tape at 8 ipm) and 120 MPa (for a 40 mm wide tape at 16 ipm). This would lead to folding and out-of-plane deformation for tapes of these widths and thicknesses.

[0123] Sintering Model 4 Figures 27 and 28 show the results when the model uses a multi-zone furnace with 10 high temperature zones and two passes (where the second pass is set at a higher temperature than the first pass). The modeled stresses are an order of magnitude lower than those shown in Figure 26, both in terms of tape transport speed and tape width. This lower stress is believed to lead to much flatter tapes, e.g., much less deformation. The model also demonstrates the effect on stress, and consequently deformation, of a controlled sintering temperature profile or gradual temperature increase during sintering.

[0124] Physical sintering test example 2 In another test example, tape-cast "green" zirconia ceramic ribbon (ceramic loaded with a polymer binder) approximately 25 micrometers thick and 15 cm wide was produced in a vertically oriented sintering apparatus at a sintering temperature of 1100°C. Approximately 50 feet (15.24 m) was produced and wound onto a 3-inch (7.62 cm) diameter take-up reel. The bisque sintering shrinkage across the width was approximately 10%.

[0125] This 1100°C "biscuit" tape was then passed through a horizontal sintering furnace substantially identical to that shown in Figure 12 at speeds of approximately 3 in. (7.62 cm) / min, 10 in. (25.4 cm) / min, 20 in. (50.8 cm) / min, 30 in. (76.2 cm) / min, 60 in. (152.4 cm) / min, and 75 in. (190.5 cm) / min, with the furnace set at 1550°C. The resulting sintered tape was 40 feet long and wound onto a 3-inch diameter take-up reel. The tape tension during sintering was on the order of 10 grams, even at 75 in. (190.5 cm) / min, and the tape was in the hot zone for less than about 15 seconds, achieving less than 20% porosity. Slower speeds resulted in denser material. Thus, this test demonstrates that a longer sintering furnace results in higher density / lower porosity in the sintered tape, and that a higher temperature results in higher density / lower porosity in the sintered tape.

[0126] Physical sintering test example 3 In another test example, tape-cast "green" alumina ceramic ribbon (ceramic loaded with a polymer binder) approximately 50 micrometers thick was fed at 4 to 6 inches (10.16 to 15.24 cm) per minute through a system substantially identical to that shown in Figure 3. The binder burnout furnace was set at 325°C at the inlet, and four central hot zones were ramped in 0 to 25°C increments to an outlet temperature of 475°C. An airflow of 5 to 7.5 liters / minute was used, ranging from approximately 0 to approximately 250°C. The sintering furnace was 36 inches (91.44 cm) long, with an 18-inch (45.72 cm) long hot zone set at 1300°C. The green tape was passed through the 18-inch (45.72 cm) sintering hot zone at 1300°C to produce a partially sintered "biscuit" tape. The width of the partially sintered tape was 7% less than the width of the green tape.

[0127] This 1300°C "biscuit" tape was then passed again through a sintering furnace at 2 inches (5.08 cm) per minute, which was set at 1550°C, producing approximately 20 feet (6.096 m) of fully sintered alumina tape. The tape was wound onto a 6-inch (15.24 cm) diameter take-up reel. The tape tension was approximately 100 grams during sintering, and the sintering shrinkage across the width for the second pass was approximately 15%. After sintering, the tape was translucent to nearly transparent. When the tape was placed over a document, the document could be read through the tape. The grain size was less than about 2 micrometers, and the material had a porosity of less than about 1%.

[0128] Test Example 4 In another test example, tape-cast "green" zirconia ceramic ribbon (ceramic loaded with a polymer binder) approximately 50 micrometers thick was fed at 6 inches (15.24 cm) per minute through a system nearly identical to that shown in Figure 3. The binder burnout furnace was set at 300-475°C and contained an airflow of 200-250°C at ~7.5 liters / min. The sintering furnace was 36 inches (91.44 cm) long with an 18-inch (45.72 cm) hot zone. The temperature gradient was 25°C to 1225°C over less than 9 inches (22.86 cm) and 1000°C to 1225°C over 3-4 inches (7.62-10.16 cm). Two D-tubes spaced approximately 3 / 8 inch (0.9525 cm) apart were used to limit air circulation and reduce the temperature gradient. The tape tension was 20-60 grams, and the sintering furnace was set at 1225°C. The resulting length of 50 feet (15.24 m) of sintered zirconia was wound onto a 3-inch (7.62 cm) diameter take-up reel. The bisque sintering shrinkage across the width was approximately 12%.

[0129] To physically model a furnace with a small temperature gradient, a 1225°C sintered "biscuit" tape was passed through a single-zone furnace three times at gradually increasing temperatures. This reduced sintering shrinkage with each pass, reducing out-of-plane deformation. Specifically, the 1225°C "biscuit" tape was then passed through the furnace again at 6 inches (15.24 cm) per minute, this time set at 1325°C. This process produced 45 feet (13.716 m) of sintered zirconia tape, wound onto a 3-inch (7.62 cm) diameter take-up reel. The tape tension during sintering was 100-250 grams, and the sintering shrinkage across the width for this pass was 5-6%.

[0130] The 1325°C tape was then passed through the sintering furnace one more time (a third time) at 6 inches (15.24 cm) per minute, with the furnace set at 1425°C. Approximately 40 feet (12.192 m) of sintered zirconia tape was produced and wound onto a 3-inch (7.62 cm) diameter take-up reel. The tape tension during sintering was 100-250 grams, and the sintering shrinkage across the width for this pass was 5-6%. After this 1425°C pass, the tape was translucent to nearly transparent. When the tape was placed over a document, the document could be read through the tape.

[0131] The 1425°C tape was then passed through the sintering furnace one more time (4th time) at 3-6 in (7.62-15.24 cm) / min, this time set at 1550°C. Several feet of sintered tape were produced at 1550°C and wound onto a 3 in (7.62 cm) diameter take-up reel. The tape tension during sintering was 100-300 grams, and the sintering shrinkage (width) for this pass was 0-2%.

[0132] Sintered products Embodiments of sintered articles formed using the systems and processes described herein are now described. The sintered article can be provided in the form of a sintered tape (i.e., a continuous sintered tape) or one or more individual sintered articles. Unless otherwise indicated, the term "sintered article" is intended to refer to both a continuous sintered article and one or more individual sintered articles. Furthermore, "sintered" refers to both partially sintered articles and fully sintered articles. In one aspect, sintered article embodiments comprise previously unattainable dimensions. In one or more embodiments, the sintered articles also exhibit uniformity of certain properties along these dimensions. According to another aspect, sintered article embodiments exhibit flattenability, meaning that the sintered article can be flattened or subjected to flattening without applying significant stress to the sintered article, thereby enabling the sintered article to be successfully used in downstream processes. Another aspect relates to rolled sintered article embodiments, and yet another aspect relates to embodiments of multiple individual sintered articles. Still further embodiments include novel compositions of materials or compositions having novel microstructures, for example novel microstructures with unique grain boundaries.

[0133] 29 , a sintered article 1000 according to one or more embodiments includes a first major surface 1010, a second major surface 1020 opposite the first major surface, and a body 1030 extending between the first and second major surfaces. The body 1030 has a thickness (t) defined as the distance between the first and second major surfaces, a width (W) defined as a first dimension of one of the first and second major surfaces perpendicular to the thickness, and a length (L) defined as a second dimension of one of the first or second major surfaces perpendicular to both the thickness and the width. In one or more embodiments, the sintered article includes opposing facets 1040 that define the width (W). While, in specific embodiments, some tapes of the present technology may be longer than the tape shown in FIG. 29 , the sintered article 1000 described herein is one example of a sintered tape 40 produced using the system 10.

[0134] In one or more embodiments, the sintered article is a continuous sintered article having a width of about 5 mm or greater, a thickness of about 3 μm to about 1 mm, and a length of about 300 cm or greater, hi other embodiments, the width is less than 5 mm as described above.

[0135] In one or more embodiments, the sintered article may have a diameter of about 5 mm to about 200 mm, about 6 mm to about 200 mm, about 8 mm to about 200 mm, about 10 mm to about 200 mm, about 12 mm to about 200 mm, about 14 mm to about 200 mm, about 15 mm to about 200 mm, about 17 mm to about 200 mm, about 18 mm to about 200 mm, about 20 mm to about 200 mm, about 22 mm to about 200 mm, about 24 mm to about 200 mm, about 25 mm to about 200 mm, about 30 mm to about 200 mm, about The width is 40 mm to about 200 mm, about 50 mm to about 200 mm, about 60 mm to about 200 mm, about 70 mm to about 200 mm, about 80 mm to about 200 mm, about 90 mm to about 200 mm, about 100 mm to about 200 mm, about 5 mm to about 150 mm, about 5 mm to about 125 mm, about 5 mm to about 100 mm, about 5 mm to about 75 mm, about 5 mm to about 50 mm, about 5 mm to about 40 mm, about 5 mm to about 30 mm, about 5 mm to about 20 mm, or about 5 mm to about 10 mm.

[0136] In some embodiments, the sintered article has a width W of at least 0.5 mm, such as at least 1 mm, for example at least 2 mm, such as at least 5 mm, for example at least 8 mm, such as at least 10 mm, for example at least 15 mm, such as at least 20 mm, for example at least 30 mm, such as at least 50 mm, for example at least 75 mm, such as at least 10 cm, for example at least 15 cm, for example at least 20 cm, and / or 2 m or less, such as 1 m or less, for example 50 cm or less, for example 30 cm or less. In other embodiments, the sintered article has a different width W.

[0137] In one or more embodiments, the sintered article may have a thickness of about 3 μm to about 1 mm, about 4 μm to about 1 mm, about 5 μm to about 1 mm, about 6 μm to about 1 mm, about 7 μm to about 1 mm, about 8 μm to about 1 mm, about 9 μm to about 1 mm, about 10 μm to about 1 mm, about 11 μm to about 1 mm, about 12 μm to about 1 mm, about 13 μm to about 1 mm, about 14 μm to about 1 mm, about 15 μm to about 1 mm, about 20 μm to about 1 mm, about 25 μm to about 1 mm, about 30 μm to about 1 mm, about 35 μm to about 1 mm, about 40 μm to about 1 mm, about 45 μm to about 1 mm, about 50 μm to about 1 mm, about 100 μm to about 1 mm, about 200 μm to about 1 mm, about 300 μm to about 1 mm, about 450 μm to about 1 mm, about 500 μm to about 1 mm, about 1000 μm to about 1 mm, about 2000 μm to about 1 mm, about 3000 μm to about 1 mm, about 4500 μm to about 1 mm, about 5000 μm to about 1 mm, about 10 ... μm ~ approx. 1 mm, approx. 400 μm ~ approx. 1 mm, approx. 500 μm ~ approx. 1 mm, approx. 3 μm ~ approx. 900 μm, approx. 3 μm ~ approx. 800 μm, approx. 3 μm ~ approx. 700 μm, approximately 3 μm to approximately 600 μm, approximately 3 μm to approximately 500 μm, approximately 3 μm to approximately 400 μm, approximately 3 μm to approximately 300 μm, approximately 3 μm to approximately 200 μm, approximately 3 μm The thickness (t) of the film is from about 3 μm to about 100 μm, from about 3 μm to about 90 μm, from about 3 μm to about 80 μm, from about 3 μm to about 70 μm, from about 3 μm to about 60 μm, from about 3 μm to about 50 μm, from about 3 μm to about 45 μm, from about 3 μm to about 40 μm, from about 3 μm to about 35 μm, from about 3 μm to about 30 μm, or from about 3 μm to about 30 μm.

[0138] In some embodiments, the sintered article has a thickness t of at least 3 μm, such as at least 5 μm, for example at least 10 μm, such as at least 15 μm, for example at least 20 μm, for example at least 25 μm, such as at least 0.5 mm, for example at least 1 mm, and / or not more than 5 mm, such as not more than 3 mm, for example not more than 1 mm, for example not more than 500 μm, for example not more than 300 μm, for example not more than 100 μm. In other embodiments, the sintered article has a different thickness t.

[0139] In one or more embodiments, the sintered article is continuous and has a length of about 300 cm to about 500 m, about 300 cm to about 400 m, about 300 cm to about 200 m, about 300 cm to about 100 m, about 300 cm to about 50 m, about 300 cm to about 25 m, about 300 cm to about 20 m, about 350 cm to about 500 m, about 400 cm to about 500 m, about 450 cm to about 500 m, about 500 cm to about 500 m, about 550 cm to about 500 m, about 600 cm to about 650 m, about 600 cm to about 650 m, about 65 ... and has a length L of about 00 cm to about 500 m, about 700 cm to about 500 m, about 800 cm to about 500 m, about 900 cm to about 500 m, about 1 m to about 500 m, about 5 m to about 500 m, about 10 m to about 500 m, about 20 m to about 500 m, about 30 m to about 500 m, about 40 m to about 500 m, about 50 m to about 500 m, about 75 m to about 500 m, about 100 m to about 500 m, about 200 m to about 500 m, or about 250 m to about 500 m. In some embodiments, the sintered article has a continuous, unbroken length L of at least 5 mm, such as at least 25 mm, for example at least 1 cm, for example at least 15 cm, for example at least 50 cm, for example at least 1 m, for example at least 5 m, for example at least 10 m, and / or 5 km or less, for example 3 km or less, for example 1 km or less, for example 500 m or less, for example 300 m or less, for example 100 m or less. In other embodiments, the sintered article has a different length L. Such continuous, long lengths, particularly of the materials and qualities disclosed herein, may be surprising to one of ordinary skill in the art without the techniques disclosed herein, such as controlled separation, tension control, sintering zones, debindering techniques, etc.

[0140] In one or more embodiments, the body of the sintered article comprises a sintered inorganic material. In one or more embodiments, the inorganic material comprises an interface having a major interface dimension of less than about 1 mm. As used herein, the term "interface," when used with respect to an inorganic material, is defined to include chemical heterogeneity, or crystalline structure heterogeneity, or both chemical heterogeneity and crystalline structure heterogeneity.

[0141] Exemplary inorganic materials include ceramic materials, glass-ceramic materials, etc. In some embodiments, the inorganic material may include any one or more of a piezoelectric material, a thermoelectric material, a pyroelectric material, a variable resistance material, or a photoelectric material. Specific examples of inorganic materials include zirconia (e.g., yttria-stabilized zirconia), alumina, spinel, garnet, lithium lanthanum zirconium oxide (LLZO), cordierite, mullite, perovskite, pyrochlore, silicon carbide, silicon nitride, boron carbide, bismuth sodium titanate, barium titanate, titanium diboride, silicon nitride alumina, aluminum oxynitride, or reactive ceramized glass-ceramic (a glass-ceramic formed by a combination of a chemical reaction and devitrification, including an in situ reaction between a glass frit and one or more reactant powders).

[0142] In one or more embodiments, the sintered article exhibits compositional uniformity over a certain area. In one or more specific embodiments, the sintered article includes an area of ​​at least 10 square centimeters having a composition (i.e., relative amounts of chemicals in weight percent (%)) along its length, where at least one component of the composition varies by less than about 3% by weight (e.g., about 2.5% by weight or less, about 2% by weight or less, about 1.5% by weight or less, about 1% by weight or less, or about 0.5% by weight or less) over the area. For example, if the inorganic material includes alumina, the amount of alumina can vary by less than about 3% by weight (e.g., about 2.5% by weight or less, about 2% by weight or less, about 1.5% by weight or less, about 1% by weight or less, or about 0.5% by weight or less) over an area of ​​at least 10 square centimeters. Such compositional uniformity may be due, at least in part, to the novel and unique processes disclosed herein, such as furnace heating zones with independently controlled elements, careful and delicate handling of the substrate tape, the steady state of continuous tape processing, etc. In other embodiments, novel and inventive tapes or other products of at least some of the technology disclosed herein may not possess such compositional uniformity.

[0143] In one or more embodiments, the sintered article exhibits uniformity of crystalline structure across a specified area. In one or more specific embodiments, the sintered article includes an area of ​​at least 10 square centimeters along its length having a crystalline structure, the crystalline structure having at least one phase with a weight percentage that varies by less than about 5 across the area. By way of example only, a sintered article may include at least one phase that constitutes 20 weight percent of the sintered article, with the amount of this phase being between about 15 weight percent and about 25 weight percent across the at least 10 square centimeter area. In one or more embodiments, the sintered article comprises an area of ​​at least 10 square centimeters along its length having a crystalline structure having at least one phase with a weight percent that varies across the area by less than about 4.5 parts per million, less than about 4 parts per million, less than about 3.5 parts per million, less than about 3 parts per million, less than about 2.5 parts per million, less than about 2 parts per million, less than about 1.5 parts per million, less than about 1 part per million, or less than about 0.5 parts per million. Such crystalline structure uniformity may be due, at least in part, to the novel and unique processes disclosed herein, such as furnace heating zones with independently controlled elements, careful and delicate handling of the green tape, the steady state of continuous tape processing, and the like. In other embodiments, novel and inventive tapes or other products of at least some of the technology disclosed herein may not have such crystalline structure uniformity.

[0144] In one or more embodiments, the sintered article exhibits uniformity of porosity across a given area. In one or more specific embodiments, the sintered article comprises an area of ​​at least 10 square centimeters, the porosity of which varies along its length by less than about 20%. As used herein, the term "porosity" is described as a volume percent (e.g., at least 10 volume percent, or at least 30 volume percent), where "porosity" refers to the portion of the volume of the sintered article not occupied by inorganic material. Thus, as an example, a sintered article may have a porosity of 10 volume percent, the porosity being in the range of from greater than about 8 volume percent to less than about 12 volume percent across an area of ​​at least 10 square centimeters. In one or more specific embodiments, the sintered article comprises an area along its length of at least 10 square centimeters having a porosity that varies over said area by 18% or less, 16% or less, 15% or less, 14% or less, 12% or less, 10% or less, 8% or less, 6% or less, 5% or less, 4% or less, or about 2% or less. Such porosity uniformity may be due, at least in part, to the novel and unique processes disclosed herein, such as furnace heating zones with independently controlled elements, careful and delicate handling of the green tape, the steady state of continuous tape processing, etc. In other embodiments, novel and inventive tapes or other products of at least some of the technology disclosed herein may not have such porosity uniformity.

[0145] In one or more embodiments, the sintered article exhibits a grain profile that, when viewed under a microscope, includes grains 1034 protruding generally outward from the body 1030, the grains 1034 having a height H (e.g., average height) of at least 25 nanometers (nm) and / or no more than 150 micrometers (μm) relative to concave portions of the surface of the boundaries 1032 between the grains 1034, as illustrated in the digital image of FIG. 30A and conceptually illustrated in the side view of FIG. 30B as an example of such a grain profile structure. In one or more embodiments, the height H is about 25 nm to about 125 μm, about 25 nm to about 100 μm, about 25 nm to about 75 μm, about 25 nm to about 50 μm, about 50 nm to about 150 μm, about 75 nm to about 150 μm, about 100 nm to about 150 μm, or about 125 nm to about 150 μm. In one or more embodiments, the height H is about 25 nm to about 125 nm, about 25 nm to about 100 nm, about 25 nm to about 75 nm, about 25 nm to about 50 nm, about 50 nm to about 150 nm, about 75 nm to about 150 nm, about 100 nm to about 150 nm, or about 125 nm to about 150 nm. In other embodiments, the height H may be other sizes. In still other embodiments, the processing conditions (e.g., time, temperature) may be such that the height H of the sintered material is approximately zero. In some embodiments, for the materials and processes disclosed herein, the product (e.g., tape) comprises a grain height H of at least 25 nm, such as at least 50 nm, such as at least 75 nm, such as at least 100 nm, such as at least 125 nm, such as at least 150 nm, and / or 200 μm or less, such as 150 μm or less, such as 100 μm or less, such as 75 μm or less, such as 50 μm or less. The size and shape of such microstructures can be controlled using techniques disclosed herein, such as the speed of transport through the oven, one or more temperatures and temperature profiles of the oven, the composition of the inorganic material in the substrate tape, particle / grain size and density, and other factors disclosed herein.

[0146] The grain profile is, or can be, an indicator of the manufacturing process used to form the sintered article 1000. In particular, the grain profile is, or can be, an indicator that the article 1000 was sintered as a thin continuous article (i.e., as a sheet or tape) rather than cut from a boule, and that each surface 1010, 1020 is substantially unpolished. Furthermore, compared to polished surfaces, the grain profile can provide benefits to the sintered article 1000 in some applications, such as light scattering for display backlight units, enhancing coating adhesion, or increasing surface area for culture growth. In contemplated embodiments, the surfaces 1010, 1020 have a roughness of about 10 nm to about 1000 nm, e.g., about 15 nm to about 800 nm, over a distance of 10 mm in one dimension along the length of the sintered article. In contemplated embodiments, one or both of the surfaces 1010, 1020 have a roughness of about 1 nm to about 10 μm over a distance of 1 cm along a single axis.

[0147] In one or more embodiments, one or both surfaces 1010, 1020 may be polished, where grain boundary grooves and grain roughness (or small bumps) are generally removed by polishing. In contemplated embodiments, the sintered article 1000 produced by the processes disclosed herein may be polished to have a surface similar to that shown in FIGS. 31A-31B, for example, depending on the particular intended use of the article. For example, to use the sintered article 1000 as a substrate, an extremely smooth, flat surface may not be required, and the unpolished surface of FIGS. 30A-30B may be sufficient, but to use the article as a mirror or lens, polishing as shown in FIGS. 31A-31B may be necessary. However, as disclosed herein, polishing can be difficult, especially for thin articles, or articles that are both thin and have a large surface area. As indicated, the substrates disclosed herein may receive coatings that can alter surface qualities, such as smoothness.

[0148] Without being bound by theory, sintered ceramic or other material sheets cut from a boule may not have readily discernible grain boundaries on their surfaces, in contrast to the articles of FIGS. 30A-30B. While not being bound by theory, articles cut from a boule are typically polished to correct rough surfaces resulting from cutting, such as grooves resulting from friction. However, polishing surfaces can be particularly difficult or tedious for extremely thin articles of sintered ceramic or other material, and the difficulty increases with thinner articles and the surface area of ​​the articles. However, sintered articles produced by the techniques of the present disclosure may be less limited by such constraints because they can be continuously produced as long tapes. Furthermore, furnace systems as disclosed herein can be scaled to accommodate and sinter the wider articles described herein.

[0149] In some embodiments, such as when the sintered article 1000 is in the form of a sheet or tape, the surface consistency is such that one or both of the first surface 1010 and the second surface 1020 have few surface defects. In this context, surface defects are friction and / or adhesion defects having dimensions of at least 15 μm, 10 μm, and / or 5 μm along each surface. In one or more embodiments, one or both of the first major surface 1010 and the second major surface 1020 have fewer than 15, fewer than 10, and / or fewer than 5 surface defects per square centimeter having dimensions greater than 15 μm, greater than 10 μm, and / or greater than 5 μm. By way of example, one or both of the first major surface 1010 and the second major surface 1020 have, on average, fewer than 3 or fewer than 1 such surface defects per square centimeter. In one or more embodiments, one or both of the first and second major surfaces have an area of ​​at least 10 square centimeters with fewer than 100 surface defects greater than 5 μm in size due to adhesion or friction. Alternatively, or in addition, one of the first and second major surfaces has an area of ​​at least 10 square centimeters with fewer than 100 surface defects greater than 5 μm in size due to adhesion or friction, while the other of the first and second major surfaces has surface defects greater than 5 μm in size due to adhesion or friction. Accordingly, sintered articles produced by the inventive techniques disclosed herein can have a relatively high and consistent surface quality. Applicant believes that this high and consistent surface quality of the sintered article 1000 promotes increased strength of the article 1000 by reducing sites of stress concentration and / or crack initiation.

[0150] The sintered article can be described as having a flatness of about 0.1 μm (100 nm) to about 50 μm over a distance of 1 cm along a single axis (e.g., along the length or width of the sintered article, etc.). In some embodiments, the flatness is about 0.2 μm to about 50 μm, about 0.4 μm to about 50 μm, about 0.5 μm to about 50 μm, about 0.6 μm to about 50 μm, about 0.8 μm to about 50 μm, about 1 μm to about 50 μm, about 2 μm to about 50 μm, about 5 μm to about 50 μm, about 10 μm to about 50 μm, about 20 μm to about 50 μm, about 25 μm to about 50 μm, or about 30 μm to about 50 μm. The surface roughness may be about 0.1 μm, about 30 μm to about 50 μm, about 0.1 μm to about 45 μm, about 0.1 μm to about 40 μm, about 0.1 μm to about 35 μm, about 0.1 μm to about 30 μm, about 0.1 μm to about 25 μm, about 0.1 μm to about 20 μm, about 0.1 μm to about 15 μm, about 0.1 μm to about 10 μm, about 0.1 μm to about 5 μm, or about 0.1 μm to about 1 μm. Such flatness, combined with the surface quality, surface consistency, large area, thin thickness, and / or material properties of the materials disclosed herein, can make sheets, substrates, sintered tapes, articles, and the like, particularly useful for a variety of applications, such as strong cover sheets for displays, high-temperature substrates, flexible separators, and other applications. That said, embodiments do not have to have such flatness. Flatness is measured using national standards (eg, ASTM A1030).

[0151] In one or more embodiments, the sintered article exhibits a filigree profile along the width dimension, as shown in FIG. 32. In one or more embodiments, the body 1030 has a filigree profile with a generally constant thickness along the width. For example, the thickness along the entire width is between about 0.9t and about 1.1t (e.g., between about 0.95t and about 1.1t, between about 0.1t and about 1.1t, between about 0.105t and about 1.1t, between about 0.9t and about 1.05t, between about 0.9t and about t, or between about 0.9t and about 0.95t), where t is a thickness value disclosed herein. As shown in FIG. 32, the filigree profile includes two or more undulations along the width. As used herein, "undulation" means a complete period. In some embodiments, the striation profile includes 3 or more undulations, 4 or more undulations, 5 or more undulations, or 10 or more undulations along the entire width, with an upper limit of less than about 20 undulations along the entire width. In one or more embodiments, the striations can be measured in terms of optical distortion. In one or more embodiments, the sintered article can be placed near a zebraboard, which consists of a white board with straight black stripes arranged diagonally across the board. When viewing the zebraboard through the sintered article, distortion of the black stripes can be visually confirmed and can be measured using methods and tools known in the art. By way of example, this distortion can be measured according to ASTM C1048. In other embodiments, such as with polished or otherwise formed articles disclosed herein, distortion may be less or not present at all. In still other embodiments, the amount and / or magnitude of distortion may be greater.

[0152] In one or more embodiments, the sintered article may be planar. In one or more embodiments, a portion of the sintered article, or an individual sintered article (as described herein), may have a three-dimensional shape. For example, in one or more embodiments, a portion of the sintered article, or an individual sintered article, may have a saddle shape (having a convex shape along its width and a concave shape along its length, or a concave shape along its width and a convex shape along its length). In one or more embodiments, a portion of the sintered article, or an individual sintered article, may have a C-shape (having a single convex shape along its length). In one or more embodiments, the feature size (by which is meant the maximum height of a portion of a sintered article or an individual sintered article as measured from the plane on which it is disposed) is less than about 0.75 mm (e.g., about 0.7 mm or less, 0.65 mm or less, 0.6 mm or less, 0.55 mm or less, 0.5 mm or less, 0.45 mm or less, 0.4 mm or less, 0.35 mm or less, 0.3 mm or less, 0.25 mm or less, 0.2 mm or less, 0.15 mm or less, or 0.1 mm or less).

[0153] According to another aspect, embodiments of the sintered article can be described in terms of its planarizability, i.e., its ability to be planarized at standard room temperature (23° C.) conditions without heating the sintered article to near its melting or sintering temperature to soften the article for planarization. In some embodiments, a portion of the sintered article can be planarized. A planarizable portion of the sintered article can have a length of about 10 cm or less. In some embodiments, the sintered article can have dimensions described elsewhere herein (e.g., a width of about 5 mm or more, a thickness of about 3 μm to about 1 mm, and a length of about 300 cm or more), and a planarizable portion of the sintered article has a length of about 10 cm or less. For example, in some embodiments where the sintered article is an individual sintered article, the entire sintered article can be planarized.

[0154] As used herein, flattenability is determined by: clamping the sintered article (or a portion of the sintered article) between two rigid parallel surfaces to flatten the sintered article; or by applying a surface pressure on the first major surface 1010 of the sintered article against a rigid surface to flatten the sintered article (or a portion of the sintered article) along a flattening plane. A flattenability measurement can be expressed as the force required to clamp the sintered article (or a portion of the sintered article) flat to within 0.05 mm, 0.01 mm, or 0.001 mm of the flattening plane when the sintered article (or a portion of the sintered article) is clamped between two rigid parallel surfaces. Alternatively, the measure of flattenability can be expressed as the surface pressure applied to the first major surface 1010 to press the sintered article (or portion of the sintered article) flat to within 0.001 mm of the flattening plane when the sintered article (or portion of the sintered article) is pressed against a rigid surface. The measure of flattenability can be expressed as the absolute maximum plane surface stress (compressive or tensile) on the sintered article (or portion of the sintered article) when the sintered article (or portion of the sintered article) is flattened to within 0.05 mm, 0.01 mm, or 0.001 mm of the flattening plane using any flattening method (i.e., clamping between two rigid parallel surfaces or pressing against a rigid surface). This stress can be calculated using the sheet bending stress equation: σ x =Et / 2R(1-ν 2 ) can be determined using

[0155] The equation for this thin plate bending stress is as follows: σ x =[E / (1-ν 2 )]·(ε x +νε y ), where E is the elastic modulus, ν is Poisson's ratio, and ε x and ε y is the strain in each direction. For a thick beam, where the deflection is much smaller than the beam thickness, ε xHowever, if the beam thickness is significantly smaller than the bending radius (e.g., the sintered article may have a thickness of about 20 μm and be bent to a bending radius on the order of millimeters), ε y = 0. As shown in Figure 33, it is assumed that a thin plate (or sintered article) is bent into a sector shape, where the neutral axis length L0 is Θ × R (where Θ is in radians and R is the bend radius), the outer fiber length L1 is Θ × (R + t / 2) (where Θ is in radians, R is the bend radius, and t is the thickness), and the outer fiber ε x is (L1-L0) / L0, so ε x = [Θ×(R+t / 2)-(Θ×R)]×1 / (Θ×R)=t / 2R. Equation σ x =[E / (1-ν 2 )]·t / 2R is the thin plate bending stress equation (σ x =Et / 2R(1-ν 2 )) becomes.

[0156] In one or more embodiments, the sintered article, or a portion of a sintered article, when flattened to at least the extent described above, exhibits a maximum in-plane stress (defined as the maximum absolute value of the stress determined by the sheet bending stress equation, regardless of whether the stress is compressive or tensile) that is 25% or less of the bending strength of the sintered article (as measured by two-point bending strength). For example, the maximum in-plane stress of the sintered article, or a portion of a sintered article, can be 24% or less, 22% or less, 20% or less, 18% or less, 16% or less, 15% or less, 14% or less, 12% or less, 10% or less, 5% or less, or 4% or less of the bending strength of the sintered article.

[0157] In one or more embodiments, a sintered article or a portion of a sintered article, when flattened as described herein, can be flattened such that the sintered article or portion of the sintered article exhibits a maximum in-plane stress of 1% or less of the Young's modulus of the sintered article. In one or more embodiments, the maximum in-plane stress of the sintered article can be 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less of the Young's modulus of the sintered article.

[0158] In one or more embodiments, a sintered article or a portion of a sintered article is flattenable such that when the sintered article or portion of a sintered article has a thickness of about 40 μm to about 80 μm (or other thicknesses disclosed herein) and is bent to a bend radius of more than 0.03 meters, the sintered article or portion thereof exhibits a maximum in-plane stress of less than or equal to 25% of the flexural strength of the article. In one or more embodiments, a sintered article or a portion of a sintered article is flattenable such that when the sintered article or portion of a sintered article has a thickness of about 20 μm to about 40 μm (or other thicknesses disclosed herein) and is bent to a bend radius of more than 0.015 meters, the sintered article or portion of a sintered article exhibits a maximum in-plane stress of less than or equal to 25% of the flexural strength of the article (as measured by two-point bend strength). In one or more embodiments, when the sintered article has a thickness of about 3 μm to about 20 μm (or other thicknesses disclosed herein) and is bent to a bend radius of greater than 0.0075 m, the sintered article or portion of the sintered article exhibits a maximum in-plane stress that is less than or equal to 25% of the bending strength (as measured by two-point bending strength) of the article.

[0159] In one or more embodiments, a sintered article or a portion thereof is flattenable such that when the sintered article or portion thereof has a thickness of about 80 μm (or other thickness as disclosed herein) and is bent to a bend radius of more than 0.03 m, the sintered article or portion thereof exhibits a maximum in-plane stress of less than or equal to 25% of the bending strength of the article. In one or more embodiments, a sintered article or a portion thereof is flattenable such that when the sintered article or portion thereof has a thickness of about 40 μm (or other thickness as disclosed herein) and is bent to a bend radius of more than 0.015 m, the sintered article or portion thereof exhibits a maximum in-plane stress of less than or equal to 25% of the bending strength of the article (as measured by two-point bending strength). In one or more embodiments, when a sintered article has a thickness of about 20 μm (or other thicknesses disclosed herein) and is bent to a bend radius of greater than 0.0075 m, the sintered article or a portion of the sintered article exhibits a maximum in-plane stress of less than or equal to 25% of the bending strength (measured by two-point bending strength) of the article.

[0160] In one or more embodiments, a sintered article, or a portion thereof, can be flattened using any flattening method (i.e., clamping between two rigid parallel surfaces or pressing against a rigid surface) such that the sintered article, or a portion thereof, when flattened to within 0.05 mm, 0.010 mm, or 0.001 mm of a flattening plane, exhibits a maximum in-plane stress of less than 250 MPa. In one or more embodiments, the maximum in-plane stress can be about 225 MPa or less, 200 MPa or less, 175 MPa or less, 150 MPa or less, 125 MPa or less, 100 MPa or less, 75 MPa or less, 50 MPa or less, 25 MPa or less, 15 MPa or less, 14 MPa or less, 13 MPa or less, 12 MPa or less, 11 MPa or less, 10 MPa or less, 9 MPa or less, 8 MPa or less, 7 MPa or less, 6 MPa or less, 5 MPa or less, or 4 MPa or less.

[0161] In one or more embodiments, the sintered article, or a portion thereof, is flattenable by clamping between two rigid parallel surfaces such that a force of less than 8 N (or 7 N or less, 6 N or less, 5 N or less, 4 N or less, 3 N or less, 2 N or less, 1 N or less, 0.5 N or less, 0.25 N or less, 0.1 N or less, or 0.05 N or less) is required to flatten the sintered article, or a portion thereof, to within 0.05 mm, 0.010 mm, or 0.001 mm of the flattening plane.

[0162] In one or more embodiments, the sintered article, or a portion thereof, is planarizable such that when the sintered article or a portion thereof is pressed against a rigid surface, a pressure of 0.1 MPa or less is required to press the sintered article (or a portion of the sintered article) flat to a distance of within 0.05 mm, 0.010 mm, or 0.001 mm from a planarizing plane. In some embodiments, the pressure can be about 0.08 MPa or less, about 0.06 MPa or less, about 0.05 MPa or less, about 0.04 MPa or less, about 0.02 MPa or less, about 0.01 MPa or less, about 0.008 MPa or less, about 0.006 MPa or less, about 0.005 MPa or less, about 0.004 MPa or less, about 0.002 MPa or less, about 0.001 MPa or less, or 0.0005 MPa or less.

[0163] According to another aspect, the sintered article may be a sintered tape that has been wound into a rolled sintered article, as shown in Figure 34A. In such an embodiment, the rolled sintered article includes a core 1100 and a sintered article 1200 (according to one or more embodiments described herein) wound around the core. In one or more embodiments, the core is cylindrical and has a diameter 1240 of less than 60 cm (i.e., about 20 inches). For example, the core may have a diameter of about 55 cm or less, 50 cm or less, about 48 cm or less, about 46 cm or less, about 45 cm or less, about 44 cm or less, about 42 cm or less, about 40 cm or less, about 38 cm or less, about 36 cm or less, about 35 cm or less, about 34 cm or less, about 32 cm or less, about 30 cm or less, about 28 cm or less, about 26 cm or less, about 25 cm or less, about 24 cm or less, about 22 cm or less, about 20 cm or less, about 18 cm or less, about 16 cm or less, about 15 cm or less, about 14 cm or less, about 12 cm or less, about 10 cm or less, about 8 cm or less, about 6 cm or less, about 5 cm or less, about 4 cm or less, or about 2 cm or less. In other embodiments, the core is another shape and the roll is bent around the core with a curvature corresponding to the above-mentioned diameter dimensions.

[0164] In one or more embodiments, the sintered article wrapped around the core is continuous and has dimensions described elsewhere herein (e.g., a width of 5 mm or more, a thickness of about 3 μm to about 1 mm, and a length of about 30 cm or more).

[0165] Winding a continuous sintered article (especially a continuous sintered inorganic material such as a ceramic) onto a core presents several challenges because the sintered article has a cross-web shape and can withstand very low web tensions (e.g., gram-level tensions), especially in the binder burnout and bisque state. Furthermore, the modulus of elasticity of the sintered article can be very high (e.g., up to about 210 GPa), so the sintered article does not stretch under tension and, when wound around a core, the integrity of the resulting wound roll can be poor. During handling of the successive wraps, the continuous sintered article can easily stretch (i.e., the successive wraps can move out of alignment).

[0166] Applicant has discovered that the use of a compatible interlayer support material when winding the continuous sintered article onto a core provides superior integrity for the rolled sintered article of one or more embodiments. In one or more embodiments, the continuous sintered article is placed on the interlayer support material, and the continuous sintered article and interlayer support material are wound around the core, such that each of the multiple successive wraps of the continuous sintered article is separated from each other by the interlayer support material. As described above with reference to FIG. 3 , the sintered article (or sintered tape material) 40 is wound onto an intake reel 44. An interlayer support material 46 is unwound or can be unwound from a reel 48, and the interlayer support material 46 can be wound or can be wound onto the intake reel 44 so as to be positioned between each, most, or at least some of the layers (e.g., sintered article 1200 or sintered tape material 40) of the continuous sintered article 1000 on the intake reel 44. This arrangement forms a rolled sintered material 50.

[0167] 34B, a detailed cross-sectional view of the rolled sintered article 1200 of FIG. 34A is shown according to an example embodiment, where the sintered article 1200 is wrapped twice around the core 1100, with interlayer support material 46 positioned between the sintered article 1200 and the core 1100 and between successive wraps of the sintered article 1200. As can be intuitively seen from FIG. 34B, when viewed from the end, the sintered article 1200 (in this case, tape) and interlayer support material 46 form alternating spirals around the core 1100. In other possible embodiments, the sintered article may be cut into individual sheets and still be wrapped on the core, separated from adjacent wraps by a continuous interlayer support material 46, for example, where the net length of the sheets together is length L as described herein. As shown in FIG. 34B , in various embodiments, a rolled sintered article is shown including an interlayer support material 46 between each layer of the rolled sintered article (e.g., sintered article 1000, sintered article 1200, or sintered tape material 40) according to an exemplary embodiment. In various embodiments, the interlayer support material comprises: a first major surface and a second major surface opposite the first major surface; an interlayer thickness (t), defined as the distance between the first and second major surfaces; an interlayer width, defined as a first dimension of one of the first and second surfaces perpendicular to the interlayer thickness; and an interlayer length, defined as a second dimension of one of the first and second surfaces perpendicular to both the interlayer thickness and the interlayer width of the interlayer support material. In one or more exemplary embodiments, the interlayer thickness is greater than the thickness of the sintered article. In one or more embodiments, the interlayer width can be greater than the width of the rolled sintered article.

[0168] In one or more embodiments, the interlayer support material 46 includes (or is under) a tension greater than the tension on the continuous sintered article, as measured by a load cell. In one or more embodiments, the interlayer support material has a relatively low modulus of elasticity (compared to the sintered article) and is therefore stretched under less tension. This is believed to produce a higher interlayer roll pressure, which improves the integrity of the wound roll. Furthermore, in some embodiments, the tension of the wound roll is controlled by controlling the tension applied to the interlayer support material, and this tension may be graded as a function of the diameter of the wound roll. In some such embodiments, the interlayer support material 46 is under tension and the sintered article (e.g., tape) is under compression.

[0169] In one or more embodiments, the interlayer support material is thickness-conforming (i.e., its thickness can be reduced by applying pressure to a major surface, thus compensating for variations in the cross-web shape or thickness of the sintered article produced by the sintering process). In some such embodiments, when viewed from the side, the sintered article may be hidden in the roll by the interlayer support material, where the interlayer support material contacts adjacent turns of the interlayer support material and shields and isolates the sintered article to at least some extent, for example, where the interlayer support material is wider than the sintered article and extends beyond both widthwise edges of the sintered article (e.g., tape), as shown in FIG.

[0170] 34A , in one or more embodiments, the rolled article is on a cylindrical core and has a generally constant diameter 1220 and sidewall width 1230. The interlayer support material allows the continuous or discontinuous sintered article to be wound around the core without stretching, which could increase the sidewall width of the rolled article. In some embodiments, the core has a periphery and a core centerline along the periphery, and the continuous sintered article has an article centerline along its length, and the distance between the core centerline and the article centerline is 2.5 mm or less along at least 90% or the entire length of the continuous or discontinuous sintered article.

[0171] In one or more embodiments, the rolled article has friction between the interlayer support material and the continuous or discontinuous sintered articles, sufficient to withstand lateral expansion and contraction of successive wraps of the wound roll, even when very little tension is applied to the interlayer support material. While a constant tension may be applied to the interlayer support material, the tension applied to the inner portion of the rolled article toward the core may be greater than the tension applied to the outer portion of the rolled article away from the core. This is because the diameter of the rolled article increases from the core toward the outer portion as more interlayer support material and continuous sintered articles are wrapped around the core. This may compress or compress the rolled article, and this compression, combined with the friction between the interlayer support material and the continuous sintered articles, prevents or limits expansion and contraction and relative movement between the surfaces of the sintered articles, at least to help prevent defects.

[0172] In one or more embodiments, the interlayer support material includes either or both of a polymer and a paper. In some embodiments, the interlayer support material is a combination of a polymer and a paper. In one or more embodiments, the interlayer support material may include a foamed polymer. In some embodiments, the foamed polymer is closed cell.

[0173] According to another aspect, the sintered articles described herein can be provided as a plurality of individual sintered articles, such as those disclosed above and illustrated in FIGS. 35 and 36 . In one or more embodiments, the individual sintered articles may be formed from a rolled sintered article or a continuous sintered article, as described herein. For example, the individual sintered articles may be laser cut or otherwise separated from a larger sintered article (which may be in sheet or tape form). In one or more embodiments, each of the plurality of individual sintered articles has uniformity or consistency with some or all of the other members of the plurality of individual sintered articles, which may be due to improved process and material properties described herein. In one or more embodiments, each of the plurality of individual sintered articles includes a first major surface, a second major surface opposite the first major surface, and a body extending between the first and second surfaces. The body comprises a sintered inorganic material and: a thickness (t), defined as the distance between a first major surface and a second major surface; a width, defined as a first dimension of one of the first and second surfaces perpendicular to the thickness; and a length, defined as a second dimension of one of the first and second surfaces perpendicular to both the thickness and the width. Intuitively, individual sheets or other sintered articles cut or formed from a longer tape will have the uniform and consistent composition, uniform and consistent crystalline structure, uniform and consistent thickness, level of defects, as disclosed above, and other properties described herein that are or may be present in tapes or other elongated articles produced using the inventive equipment and processes disclosed herein.

[0174] In one or more embodiments, some, most, or each of the plurality of sintered articles can be flattened as described herein. In one or more embodiments, some, most, or each of the plurality of sintered articles, when flattened, exhibits a maximum in-plane stress (defined as the maximum absolute value of the stress determined by the sheet bending stress equation, regardless of whether the stress is compressive or tensile) that is 25% or less of the bending strength (measured by two-point bending) of the sintered article. For example, the maximum in-plane stress of some, most, or each of the plurality of sintered articles can be 24% or less, 22% or less, 20% or less, 18% or less, 16% or less, 15% or less, 14% or less, 12% or less, 10% or less, 5% or less, or 4% or less of the bending strength of the sintered article.

[0175] In one or more embodiments, some, most, or each of the plurality of sintered articles can be planarized such that, when planarized as described herein, some, most, or each of the plurality of sintered articles exhibits a maximum in-plane stress of 1% or less of the Young's modulus of the sintered article. In one or more embodiments, the maximum in-plane stress of some, most, or each of the plurality of sintered articles can be 0.9% or less, 0.8% or less, 0.7% or less, 0.6% or less, 0.5% or less, 0.4% or less, 0.3% or less, 0.2% or less, 0.1% or less, or 0.05% or less of the Young's modulus of each sintered article.

[0176] In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article has a thickness of about 40 μm to about 80 μm (or other thicknesses disclosed herein) and is bent to a bend radius of more than 0.03 m, the sintered article exhibits a maximum in-plane stress of no more than 25% of the flexural strength of the article. In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article has a thickness of about 20 μm to about 40 μm (or other thicknesses disclosed herein) and is bent to a bend radius of more than 0.015 m, the sintered article exhibits a maximum in-plane stress of no more than 25% of the flexural strength of the article (as measured by two-point bend strength). In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that the sintered article has a thickness of about 3 μm to about 20 μm (or other thickness as disclosed herein) and exhibits a maximum in-plane stress of less than or equal to 25% of the bending strength (as measured by two-point bending strength) of the article when bent to a bend radius of greater than 0.0075 m.

[0177] In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article has a thickness of about 80 μm (or other thickness as disclosed herein) and is bent to a bend radius of more than 0.03 m, the sintered article exhibits a maximum in-plane stress of less than or equal to 25% of the flexural strength of the article. In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article has a thickness of about 40 μm (or other thickness as disclosed herein) and is bent to a bend radius of more than 0.015 m, the sintered article exhibits a maximum in-plane stress of less than or equal to 25% of the flexural strength of the article (as measured by two-point bend strength). In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article has a thickness of about 20 μm (or other thickness as disclosed herein) and is bent to a bend radius of greater than 0.0075 m, the sintered article exhibits a maximum in-plane stress of less than or equal to 25% of the bending strength (measured by two-point bending strength) of the article.

[0178] In one or more embodiments, some, most, or each of the plurality of sintered articles can be flattened using any flattening method (i.e., clamping between two rigid parallel surfaces or pressing against a rigid surface) such that the sintered articles exhibit a maximum in-plane stress of less than 250 MPa when flattened to within 0.05 mm, 0.01 mm, or 0.001 mm of a flattening plane. In one or more embodiments, the maximum in-plane stress can be about 225 MPa or less, 200 MPa or less, 175 MPa or less, 150 MPa or less, 125 MPa or less, 100 MPa or less, 75 MPa or less, 50 MPa or less, 25 MPa or less, 15 MPa, 14 MPa or less, 13 MPa or less, 12 MPa or less, 11 MPa or less, 10 MPa or less, 9 MPa or less, 8 MPa or less, 7 MPa or less, 6 MPa or less, 5 MPa or less, or 4 MPa or less.

[0179] In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable by clamping between two rigid parallel surfaces such that flattening the sintered article to a distance of within 0.05 mm, 0.010 mm, or 0.001 mm from a flattening plane requires a force of less than 8 N (or 7 N or less, 6 N or less, 5 N or less, 4 N or less, 3 N or less, 2 N or less, 1 N or less, 0.5 N or less, 0.25 N or less, 0.1 N or less, or 0.05 N or less) to flatten the sintered article or each portion thereof.

[0180] In one or more embodiments, some, most, or each of the plurality of sintered articles is flattenable such that when the sintered article is pressed against a rigid surface, a pressure of 0.1 MPa or less is required to press the sintered article flat to within 0.05 mm, 0.01 mm, or 0.001 mm of a flattening plane. In some embodiments, the pressure can be about 0.08 MPa or less, about 0.06 MPa or less, about 0.05 MPa or less, about 0.04 MPa or less, about 0.02 MPa or less, about 0.01 MPa or less, about 0.008 MPa or less, about 0.006 MPa or less, about 0.005 MPa or less, about 0.004 MPa or less, about 0.002 MPa or less, about 0.001 MPa or less, or 0.0005 MPa or less.

[0181] In one or more embodiments, some, most, or each of the sintered articles has a thickness of about 0.7t to about 1.3t (e.g., about 0.8t to about 1.3t, about 0.9t to about 1.3t, about t to about 1.3t, about 1.1t to about 1.3t, about 0.7t to about 1.2t, about 0.7t to about 1.1t, about 0.7t to about 1t, or about 0.9t to about 1.1t), where t is a thickness value disclosed herein.

[0182] In one or more embodiments, some, most, or each of the plurality of sintered articles exhibits compositional uniformity. In one or more embodiments, at least 50% (e.g., about 55% or more, about 60% or more, or about 75% or more) of the plurality of sintered articles comprise an area and a composition where at least one component of the composition (as described herein) varies by less than about 3% by weight across the area. In some embodiments, at least one component of the composition varies by about 2.5% by weight or less, about 2% by weight or less, about 1.5% by weight or less, about 1% by weight or less, or about 0.5% by weight or less across the area. In one or more embodiments, the area is about 1 square centimeter of the sintered article, or the area is the total surface area of ​​the sintered article.

[0183] In one or more embodiments, some, most, or each of the plurality of sintered articles exhibits uniformity of crystalline structure. In one or more embodiments, at least 50% (e.g., about 55% or more, about 60% or more, or about 75% or more) of the plurality of sintered articles comprise a crystalline structure having an area and at least one phase having a weight percentage (as described herein) that varies by less than about 5 parts per million across the area. By way of example only, some, most, or each of the plurality of sintered articles may include at least one phase that constitutes 20% by weight of the sintered article, and at least 50% (e.g., about 55% or more, about 60% or more, or about 75% or more) of the plurality of sintered articles, where the phase is present in an amount of about 15% to about 25% by weight across the area. In one or more embodiments, some, a majority, or at least 50% (e.g., about 55% or more, about 60% or more, or about 75% or more) of the plurality of sintered articles comprise an area and a crystalline structure having at least one phase with a weight percentage that varies across the area by less than about 4.5 parts per million, less than about 4 parts per million, less than about 3.5 parts per million, less than about 3 parts per million, less than about 2.5 parts per million, less than about 2 parts per million, less than about 1.5 parts per million, less than about 1 part per million, or less than about 0.5 parts per million. In one or more embodiments, the area is about 1 square centimeter of the sintered article, or the area is the total surface area of ​​the sintered article.

[0184] In one or more embodiments, at least 50% (e.g., about 55% or more, about 60% or more, or about 75% or more) of the plurality of sintered articles have an area and a porosity (as described herein) that varies by less than about 20%. Thus, by way of example, some, most, or each of the plurality of sintered articles has a porosity of 10% by volume, the porosity being in the range of from greater than about 8% to less than about 12% by volume across the area of ​​at least 50% of the plurality of sintered articles. In one or more embodiments, at least 50% of the plurality of sintered articles have an area and a porosity that varies by no more than 18%, no more than 16%, no more than 15%, no more than 14%, no more than 12%, no more than 10%, no more than 8%, no more than 6%, no more than 5%, no more than 4%, or no more than about 2% across the area. In one or more embodiments, the area is about 1 square centimeter of the sintered article, or the area is the total surface area of ​​the sintered article.

[0185] Examples 5 to 6 and Comparative Examples 7 to 8 Examples 5-6 and Comparative Examples 7-8 are individual sintered articles formed from a series of sintered articles of tetragonal or tetrazirconia polycrystalline material. Examples 5-6 were formed by the process and system described herein, while Comparative Examples 7-8 were formed using other processes and systems that did not include at least some of the techniques of this disclosure (e.g., tension control, zoned sintering furnace, airflow control). Examples 5-6 and Comparative Examples 7-8 each had a length of 55.88 mm, a width of 25.4 mm, a thickness of 0.04 mm, and a corner radius of 2 mm. Examples 5-6 and Comparative Examples 7-8 each had a Young's modulus of 210 GPa, a Poisson's ratio (ν) of 0.32, and a tensile strength of 6 g / cm. 3 It had a density (ρ) of

[0186] Example 5 was a C-shape with a geometry of 0.350 mm, as shown in FIG. 35. Example 6 was a saddle-shape with a geometry of 0.350 mm, as shown in FIG. 36. Comparative Example 7 was a gull-wing shape with a geometry of 0.350 mm, as shown in FIG. 37. Comparative Example 8 was a gull-wing shape with a geometry of 0.750 mm, as shown in FIG. 38. The geometry of each sintered article relative to the planar surface before flattening is compared in FIG. 39.

[0187] The planarization capabilities of these examples were evaluated using two load application methods described elsewhere herein (i.e., clamping the sintered article between two rigid parallel surfaces, or applying surface pressure to one major surface of the sintered article to press the sintered article against a rigid surface and flatten the sintered article along a planarization plane).

[0188] FIG. 40 shows the force (units: N) required to clamp the sintered articles of Examples 5-6 and Comparative Examples 7-8 flat to within 0.001 mm of the flattening surface by clamping between two rigid parallel surfaces. As shown in FIG. 40, Examples 5-6 required significantly less force to flatten the sintered articles, indicating better flattenability. Furthermore, the ability to flatten the sintered articles with such low force indicates that such articles can be manipulated or subjected to downstream processing without fracture, breakage, or the formation of other defects. Downstream processing can include, for example, the application of coatings, including conductive or non-conductive coatings. This same flattenability is also demonstrated when measuring the pressure required to press the sintered articles of Examples 5-6 and Comparative Examples 7-8 flat against a rigid surface to within 0.001 mm of the flattening surface. The results are shown in Figure 41, demonstrating that Examples 5-6 required significantly less pressure for planarization compared to Comparative Examples 7-8. Figure 42 shows the maximum in-plane surface stress in the planarized sintered articles of Examples 5-6 and Comparative Examples 7-8. While Examples 5-6 exhibit stresses less than 11 MPa, Comparative Examples 7-8 exhibit stresses greater than 20 times this stress, indicating that the sintered articles of Comparative Examples 7-8 are likely to fracture, break, or have defects during downstream processing. The locations of stresses for Example 5 are shown in Figures 43A (bottom stress during planarization) and 43B (top stress during planarization). The locations of stresses for Example 6 are shown in Figures 44A (bottom stress during planarization) and 44B (top stress during planarization). The locations of stresses for Comparative Example 7 are shown in Figures 45A (bottom stress during planarization) and 45B (top stress during planarization). In Comparative Example 7, at the bottom, the central portion exhibits a tensile stress of 208.6 MPa, which is sandwiched on both sides by a compressive stress of -254.6 MPa. Correspondingly, at the front, the central portion is under a compressive stress of approximately -208.6 MPa, which is sandwiched on both sides by a tensile stress of 254.6 MPa. The location of the stresses in Comparative Example 8 is shown in Figures 46A (stress at the bottom when flattened) and 46B (stress at the top when flattened).In Comparative Example 8, at the bottom, the central portion exhibits a tensile stress of 399.01 MPa, which is sandwiched on both sides by a compressive stress of -473.63 MPa. Correspondingly, at the front, the central portion is under a compressive stress of approximately -399.08 MPa and sandwiched on both sides by a tensile stress of 473.60 MPa. The high stress at point X in Comparative Examples 7-8 indicates that these sintered articles are prone to fracture along the high stress locations.

[0189] In some semiconductor packages and similar light emitting diode (LED) containing packages, a significant portion of the electrical energy supplied to or through the package may be lost or dissipated as heat energy. The heat dissipation capability of these and similar semiconductor packages may be a limiting factor when attempting to supply additional electrical energy (or current) through the package. Additionally, in at least some LED containing packages, the heat dissipation capability of the LED containing package may limit the brightness of the LED. It may be desirable to reduce and maintain the temperature of the components within the semiconductor package, for example, at about 75°C to about 85°C.

[0190] In one or more embodiments, referring to FIG. 47 , a sintered article described herein (e.g., sintered article 1000, sintered article 1200, or sintered tape material 40) is bonded, bonded, connected, or otherwise attached, directly or indirectly, to a substrate 1500 to form a package 2000. The sintered article 1000 can function as a dielectric within the package 2000. In some embodiments, the package 2000 is a semiconductor package, an electrical package, a power transmission package, a light emitting diode (LED) package, etc. The package 2000 of the present disclosure provides improved performance (e.g., heat dissipation capabilities, lower thermal resistance, etc.) compared to conventional packages. In other such embodiments, the sintered article described herein (e.g., sintered article 1000, sintered article 1200, or sintered tape material 40) is or is also the substrate 1500.

[0191] In some embodiments, the package 2000 includes an intermediate layer 1300 between the substrate 1500 and the sintered article 1000. The intermediate layer 1300 may include a material that bonds, bonds, connects, or otherwise attaches or facilitates the attachment of the substrate 1500 and the sintered article 1000. The intermediate layer 1300 may include multiple individual layers that are bonded or bonded together to form the intermediate layer 1300. In some embodiments, the intermediate layer 1300 is a material with high thermal conductivity properties, such that heat generated by an electronic component (e.g., a semiconductor device or chip) or a metal-based layer is conducted through the intermediate layer 1300 to the substrate 1500. In some embodiments, the intermediate layer 1300 includes a thermal conductivity that is higher than that of the sintered article 1000. In some embodiments, the intermediate layer 1300 includes a thermal conductivity that is lower than that of the substrate 1500. The intermediate layer 1300 may have a thermal conductivity of greater than about 8 W / m·K to about 20 W / m·K, greater than about 8 W / m·K to about 16 W / m·K, or greater than about 8 W / m·K to about 13 W / m·K, or greater than about 9 W / m·K to about 12 W / m·K, e.g., 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 W / m·K (including all ranges and subranges therebetween). In some embodiments, the intermediate layer 1300 is an adhesive-like material. In some embodiments, the intermediate layer 1300 is a compatible material configured to deform and / or withstand shear forces resulting from differences in the coefficient of thermal expansion (CTE) between the substrate 1500 and the sintered article 1000 that arise as a result of heating and cooling the package 2000.

[0192] In some embodiments, intermediate layer 1300 comprises a matrix of polyimide, epoxy, or a combination thereof. In some embodiments, the matrix of intermediate layer 1300 may include non-conductive particles (e.g., boron nitride), conductive materials (e.g., silver, copper, etc.), or a combination thereof. The conductive and / or non-conductive particles may be distributed homogeneously or heterogeneously throughout the matrix of intermediate layer 1300. In some embodiments, intermediate layer 1300 conducts heat from metal base layer 1350 and component 1401 ( FIG. 50( e) ) and transfers the conducted heat to substrate 1500. In some embodiments, intermediate layer 1300 may have a length (L) and width (W) that are approximately the same as one or both of substrate 1500 and / or sintered article 1000. In some embodiments, the intermediate layer may have a thickness (t2) of from about 0.1 μm to about 100 μm, or from about 10 μm to about 75 μm, or from about 15 μm to about 35 μm, or even from about 20 μm to about 40 μm, such as 5, 10, 15, 20, 25, 30, 35, or 40 μm (including all ranges and subranges therebetween).

[0193] In one or more embodiments, the substrate 1500 includes a first major surface 1510, a second major surface 1520 opposite the first major surface, and a body 1530 extending between the first major surface 1510 and the second major surface 1520. The sintered article 1000 may be bonded, coupled, connected, or otherwise attached, directly or indirectly, to the first major surface 1510 or the second major surface 1520 of the substrate 1500. The body 1530 has: a thickness (t1), defined as the distance between the first major surface 1510 and the second major surface 1520; a width (W1), defined as a first dimension of one of the first or second surfaces perpendicular to the thickness; and a length, defined as a second dimension of one of the first or second surfaces perpendicular to both the thickness and the width. In one or more embodiments, the substrate 1500 includes opposing facets 1540 that define a width W1. In some embodiments, the length and width of the sintered article 1000 and the substrate 1500 are each approximately equal (i.e., lateral dimensions within 5% of each other). In some embodiments, the thickness (t1) of the substrate 1500 is greater than the thickness (t) of the sintered article 1000, e.g., a thickness (t) disclosed herein for the sintered article 1000. In some embodiments, the thickness (t1) of the substrate 1500 is about 25%, about 50%, about 75%, about 100%, about 200%, about 500%, or more greater than the thickness (t) of the sintered article 1000. In some embodiments, the thickness (t1) of substrate 1500 is about 0.5 mm to about 5.0 mm, or about 1.0 mm to about 2.0 mm, or about 1.0 mm to about 1.6 mm, or even about 1.2 mm to about 1.5 mm. In some embodiments, substrate 1500 functions as a heat sink for package 2000. In some embodiments, substrate 1500 comprises a conductive metal such as aluminum, copper, or a combination thereof.

[0194] 47 and 48 provide cross-sectional views of a segment of exemplary package 2000 in which an intermediate layer 1300 bonds substrate 1500 to sintered article 1000. A metal base layer 1350 may be provided on a major surface of sintered article 1000 opposite the major surface bonded to intermediate layer 1300. That is, sintered article 1000 may include intermediate layer 1300 on one major surface and metal base layer 1350 on the opposite major surface. Intermediate layer 1300 may be applied to one or both of substrate 1500 and sintered article 1000. Substrate 1500 and sintered article 1000 may then be assembled or bonded together with intermediate layer 1300 between their respective major surfaces. The intermediate layer 1300 may be activated with thermal energy, actinic wavelengths, pressure, or other similar methods to bond, bond, connect, or otherwise attach the substrate 1500 to the sintered article 1000 via the intermediate layer 1300.

[0195] As shown in FIG. 47 , one or both of the major surfaces 1510, 1520 of the substrate 1500 may be patterned to include grooves 1325. The grooves 1325 can assist in bonding the intermediate layer 1300 to the substrate 1500. The grooves 1325 can also help minimize shear stress experienced by the intermediate layer 1300 as a result of differences in CTE between the substrate 1500 and the sintered article 1000. In some embodiments, the grooves 1325 cover at least a portion of the major surface of the substrate 1500. The grooves 1325 may have a depth of about 0.1 μm to about 1 mm, or about 10 μm to about 50 μm, in the major surface of the substrate 1500. The intermediate layer 1300 may extend at least partially into the grooves 1325 of the substrate 1500. The grooves 1325 may have a cross section that is rectangular, square, circular, triangular, or other similar shape or combination of shapes, and may be continuous, dashed, or otherwise extend across the major surface of the sintered article 1000.

[0196] The metal base layer 1350 may be directly or indirectly bonded to the sintered article 1000 by electroplating, printing, physical vapor deposition, chemical vapor deposition, sputtering, or other similar techniques. The metal base layer 1350 is an electrically conductive material capable of conducting or supplying electrical energy (or current) across and through the package 2000. In some embodiments, the metal base layer is configured to minimize electrical resistance and heat generation along its length. In some embodiments, the metal base layer 1350 comprises copper, nickel, gold, silver, brass, lead, tin, and combinations thereof. The metal base layer 1350 may be indirectly bonded to the sintered article 1000 via a seed layer 1375. That is, the seed layer 1375 can provide a foundation for bonding the metal base layer 1350 to the sintered article 1000. In some embodiments, the seed layer 1375, which bonds the metal base layer 1350 to the sintered article 1000, is "reflowed" in a reflow oven to electrically connect the metal base layer 1350 to other electronic components within the package 2000. In some embodiments, the seed layer 1375 comprises tin, titanium, tungsten, lead, or a combination thereof. The seed layer 1375 may be applied to a major surface of the sintered article 1000 by electroplating, printing, physical vapor deposition, chemical vapor deposition, sputtering, or other similar techniques.

[0197] In some embodiments, the metal-based layer 1350 may be directly or indirectly bonded to the sintered article 1000 before, during, or after bonding the sintered article 1000 to the substrate 1500. In some embodiments, the metal-based layer 1350 is a continuous, semi-continuous, or discontinuous array, or "circuit," on a major surface of the sintered article 1000. In some embodiments, before applying the metal-based layer 1350 and / or the seed layer 1375 onto the sintered article 1000, portions of one or both of the major surfaces of the sintered article 1000 may be masked or coated to prevent the metal-based layer 1350 and / or the seed layer 1375 from being applied to the masked portions of the sintered article 1000. That is, masked portions of one or both major surfaces of the sintered article 1000 can be used to form a continuous, semi-continuous, or discontinuous array, or "circuit," of the metal base layer 1350 and / or seed layer 1375 on the major surfaces of the sintered article 1000. After the metal base layer 1350 is applied to the unmasked portions of the major surfaces of the sintered article 1000, the masking can be removed to expose the portions of the major surfaces where the masking was present (which do not have the metal base layer and / or seed layer thereon). Figures 47 and 49 provide examples of metal base layers 1350 as an array on the major surfaces of the sintered article. The metal base layer 1350 comprises a thickness (t3) of about 0.1 μm to about 1 mm, or about 2 μm to about 100 μm, about 5 μm to about 70 μm, or even about 5 μm to about 50 μm.

[0198] In one or more embodiments, the package 2000 includes a semiconductor device or chip 1400. In some embodiments, the semiconductor device 1400 is bonded, coupled, connected, or otherwise attached, directly or indirectly, to the first major surface 1010 or the second major surface 1020 of the sintered article 1000. The semiconductor device 1400 may be indirectly bonded to the sintered article 1000 via a seed layer 1375, as shown in FIG. 49 . The semiconductor device 1400 may include one or more light emitting diodes (LEDs). In some embodiments, the semiconductor device 1400 is connected to the metal base layer 1350 by one or more leads 1450. The leads 1450 may be rigid or flexible wires or electrical connectors (e.g., similar to the metal base layer 1350) that electrically connect the semiconductor device 1400 and the metal base layer 1350. 47 and 49 show the leads 1450 as spanning the distance between the semiconductor device 1400 and the metal base layer 1350. Of course, the leads 1450 may, in one or more embodiments, extend along or contact the surface of the sintered article 1000. The leads 1450 can provide electrical energy between the metal base layer 1350 and the semiconductor device 1400. In some embodiments, electrical energy passing through the metal base layer 1350 is transferred to the semiconductor device 1400 through the leads 1450. In some embodiments, the electrical energy provided to the semiconductor device 1400 powers LEDs thereon, which emit one or more wavelengths of light (λ). The semiconductor device 1400 may include one or more lenses 1405 to enhance the light from the LEDs thereon. The semiconductor device 1400 may also include a phosphor material 1475 for filtering and transmitting specific wavelengths (λ) from the wavelengths (λ) emitted by the LED.

[0199] In one or more embodiments, a method of making a package 2000 includes providing sintered articles 1000. The sintered articles 1000 may be a roll including a rounded or cylindrical core less than 60 cm in diameter, with continuous sintered articles wound around the core. The sintered articles 1000 may also be provided as individual, flattened lengths. In one or more embodiments, a method of making a package 2000 includes providing a carrier or temporary substrate 1499 (FIG. 50), which may be a roll or a large, flat sheet. In some embodiments, a length of sintered articles 1000 is bonded, bonded, connected, or otherwise attached to a length of carrier or temporary substrate 1499 to form a package precursor 1999. The carrier or temporary substrate 1499 may support the sintered articles 1000 for later winding onto the core. In some embodiments, the carrier or temporary substrate 1499 may support the sintered article 1000 during subsequent processes that may damage, degrade, or destroy the substrate 1500. In some embodiments, the carrier or temporary substrate 1499 comprises glass, a polymer, or a combination thereof. In some embodiments, the carrier or temporary substrate 1499 is a polymeric material, such as polyamide tape.

[0200] In some embodiments, the packaging precursor 1999 includes an interlayer precursor 1299 ( FIG. 50 ) between the sintered article 1000 and the temporary substrate 1499. The interlayer precursor 1299 may include a material that bonds, bonds, connects, or otherwise attaches the temporary substrate 1499 and the sintered article 1000. In some embodiments, the interlayer precursor 1299 is a high-temperature resistant adhesive. The interlayer precursor 1299 can be activated with thermal energy, actinic wavelengths, pressure, or other similar methods to bond, bond, connect, or otherwise attach the temporary substrate 1499 to the sintered article 1000. In some embodiments, the interlayer precursor 1299 can be deactivated by a means similar or different to the means for activation, thereby allowing the sintered article 1000 to be removed or disconnected from the temporary substrate 1499. In some embodiments, the intermediate layer precursor 1299 and temporary substrate 1499 are configured to withstand (not degrade) during subsequent processing of the package precursor 1999, including the application of the metal base layer 1350, seed layer 1375, semiconductor device 1400, leads 1450, and / or other similar components.

[0201] FIG. 50 illustrates a method of forming a package 2000 from a package predecessor 1999. Step (a) of FIG. 50 illustrates the package predecessor 1999 after a metal base layer 1350 has been applied to a major surface of the sintered article 1000 opposite the surface joined with the intermediate layer predecessor 1299. Step (a) of FIG. 50 also illustrates the package predecessor 1999 after masking has been removed from the sintered article 1000 (e.g., between the metal base layers 1350). A seed layer 1375 may be applied to the sintered article 1000 before or after step (a). Step (b) of FIG. 50 illustrates applying components of a component 1401 (i.e., semiconductor device 1400 and leads 1450) to the sintered article 1000 to electrically connect the semiconductor device 1400 and the metal base layer 1350. In some embodiments, the carrier or temporary substrate 1499 and the intermediate layer precursor 1299 are configured to support the sintered article 1000 and not deteriorate or deform during steps (a) and (b) shown in FIG. 50 , which may be performed at high temperatures (e.g., 320° C. or higher). Step (c) in FIG. 50 illustrates separating the sintered article 1000 (including the metal base layer 1350, semiconductor device 1400, and leads 1450 thereon) from the temporary substrate 1499. In some embodiments, step (c) may be performed by passivating the intermediate layer precursor 1299 with thermal energy, actinic radiation, traction, or other similar methods. In some embodiments, the sintered article 1000 (including the metal base layer 1350, semiconductor device 1400, and leads 1450 thereon) is mechanically or manually separated from the temporary substrate 1499. In some embodiments, step (c) occurs in a reflow oven while electrically connecting parts of component 1401 with seed layer 1375 or solder. Intermediate layer precursor 1299 can be transferred to sintered article 1000, temporary substrate 1499, or both (portions of each). Step (c) of Figure 50 shows an embodiment in which intermediate layer precursor 1299 is transferred to temporary substrate 1499. In some embodiments, intermediate layer precursor 1299 can become intermediate layer 1300 in subsequent processing (e.g., heating) or by bonding or contacting substrate 1500.Step (d) of Figure 50 illustrates bonding the sintered article 1000 and the substrate 1500 with the intermediate layer 1300 therebetween. In some embodiments, the intermediate layer precursor 1299 may be identical to the intermediate layer 1300. Step (e) of Figure 50 illustrates applying additional components of the component 1401 (e.g., lens 1405 and phosphor 1475) to the sintered article 1000. In some embodiments, the components of the component 1401 may be applied at relatively low temperatures (e.g., <150°C) to avoid degrading or deforming the intermediate layer 1300 and the substrate 1500 during the build of the component 1401. The package 2000 shown in step (e) of Figure 50 may include one or more components 1401.

[0202] FIG. 51 provides another exemplary method of forming a package 2000 with a package precursor 1999. Step (a) of FIG. 51 illustrates providing a flattened sintered article 1000, such as a flattened sheet, from a wound core. Step (b) of FIG. 51 illustrates bonding the flattened sintered article 1000 to a carrier or temporary substrate 1499 to form the package precursor 1999. An intermediate layer precursor 1299, or a similar such layer, may be disposed between the sintered article 1000 and the carrier or temporary substrate 1499. The package precursor 1999 can be wound onto a core for further processing, stored, shipped, or sold. Step (c) of FIG. 51 illustrates applying a metal base layer 1350 and components of a light-emitting component 1401 (e.g., semiconductor device 1400, leads 1450, lens 1405, phosphor 1475, etc.) to the sintered article 1000. Step (c) may include multiple stages of electrically connecting the metal base layer 1350 to the semiconductor device 1400 on the sintered article 1000 and any LEDs thereon. Step (c) may also include a solder reflow operation in a reflow oven to electrically connect all of the components of the component 1401. Step (d) in FIG. 51 illustrates the step of separating or delaminating the sintered article 1000 (including the component 1401) from the temporary substrate 1499. Step (d) may be accomplished by mechanically or manually separating the sintered article 1000 (including the component 1401) from the temporary substrate 1499. Step (d) may be catalyzed by heat, exposure to actinic radiation, cooling, exposure to a solvent, or other similar methods. It should be understood that the intermediate layer precursor 1299 (if present) may be transferred to the sintered article 1000, the temporary substrate 1499, or both (portions of each). Step (e) of Figure 51 illustrates bonding sintered article 1000 (including component 1401) and substrate 1500 to form package 2000. In some embodiments, sintered article 1000 (including component 1401) and substrate 1500 may be bonded with intermediate layer 1300 or a similar layer therebetween to form package 2000.Step (f) of Figure 51 illustrates cutting the package 2000 into multiple segments 2001 at multiple points along its length L4. The package 2000 may be cut into multiple segments 2001 along its length L4 using localized cutting pressure, laser energy (e.g., a UV ablation laser), or similar techniques. In some embodiments, each segment 2001 includes at least one or more components 1401. The segments 2001 of the package 2000 can be used in a variety of applications, including light bulb filaments, electronic devices, handheld devices, head-up displays, vehicle instrument panels, etc.

[0203] 52-54 show cross-sectional views of a package 2000 including the sintered article 1000 and a "flip-chip" configuration of the semiconductor device 1400. In these embodiments, a segment of the package 2000 may include an aperture 1501 in the substrate 1500. The aperture 1501 may be formed by drilling, cutting, or removing a portion of the substrate 1500. The aperture 1501 may also be formed by separating two portions of the substrate 1500 from one major surface of the sintered article 1000. In some embodiments, the metal base layer 1350 may be bonded, bonded, connected, or otherwise attached to the same major surface of the sintered article 1000 as the substrate 1500.

[0204] FIG. 52 shows an example cross-sectional view of a segment of a package 2000 including a sintered article 1000 bonded to a substrate 1500. In some embodiments, a metal base layer 1350 is disposed within the aperture 1501. That is, the metal base layer 1350 is bonded to the same major surface of the sintered article 1000 as the substrate 1500. In some embodiments, a seed layer 1375 is applied to and bonded to the metal base layer 1350. The seed layer 1375 can assist in bonding the metal base layer 1350 and the semiconductor device 1400 in a “flip-chip” configuration. In one or more embodiments, the seed layer 1375 includes tin, titanium, tungsten, lead, or alloys thereof. In some embodiments, the seed layer 1375 is electrically conductive, eliminating the need for leads to electrically connect the metal base layer and the semiconductor device 1400. In some embodiments, a volume 1485 may be formed between the sintered article 1000 and the semiconductor device 1400. The volume 1485 may be sealed between the sintered article 1000 and the semiconductor device 1400 by the metal base layer 1350 and / or the seed layer 1375. In some embodiments, the LED on the semiconductor device 1400 is opposite the volume 1485 and within the aperture 1501. In some embodiments, the LED on the semiconductor device 1400 is within the volume 1485. A phosphor material 1475 may be provided within the volume 1485. In FIGS. 52 and 53 , the sintered article 100 may be translucent or substantially transparent, allowing the light wavelengths (λ) emitted from the LED on the semiconductor device 1400 to transmit through the sintered article 1000. In some embodiments, the sintered article 1000 may transmit some, most, or all of the visible light wavelengths (λ) emitted by the LED or transmitted through the phosphor material 1475, such as about 35% to about 95%, or about 45% to about 85%, or about 55% to about 75%, e.g., 35%, 40%, 50%, 60%, 65%, 75%, 85%, 90%, 95%, or up to 99%, including all ranges and subranges therebetween.

[0205] The total light transmitted through the sintered article 1000 (T) can be defined by Equation 1 below: (1)T=Φ et / Φ e i where: Φ e t is the radiative flux transmitted through this surface; Φ e i is the radiative flux received by this surface.

[0206] Measurement of these quantities is described in ASTM Standard Test Method D1003-13.

[0207] FIG. 53 is similar to FIG. 52 but shows an intermediate layer 1300 between the sintered article 1000 and the substrate 1500. FIG. 53 also illustrates embodiments in which at least a portion of the aperture 1501 (shown in FIG. 52) is filled with the substrate 1500, which may be isolated from or connected to an adjacent portion of the substrate 1500. In other embodiments, at least a portion of the aperture 1501 is filled with a filler material (e.g., epoxy, plastic, polymer material, etc.) to encapsulate the chip 1400 and metal base layer 1350 within the package 2000. In FIG. 53, the substrate 1500 contacts the semiconductor device 1400 to conduct heat from the semiconductor device 1400 that is generated when electrical energy is supplied to the package 2000. In some embodiments, the sintered article 1000 includes holes 1490 through its thickness. As shown in FIGS. 53 and 55 , holes 1490 in sintered article 1000 intersect with volume 1485. Holes 1490 may allow the phosphor material 1475 in volume 1485 to be cooled by atmospheric convection. Holes 1490 may also allow light wavelengths (λ) from the LEDs in volume 1485 to exit package 2000. As shown in FIG. 54 , a reflector 1480 may be included within volume 1485 and / or holes 1490 to enhance or reflect the light wavelengths (λ) emitted from the LEDs on semiconductor device 1400. The reflector 1480 may have a conical, semicircular, tapered, or curved shape. In some embodiments, the reflector 1480 may be coated with a coating to enhance the light wavelengths (λ) emitted from the LEDs on semiconductor device 1400. FIG. 55 shows another possible configuration.

[0208] In one or more embodiments, the sintered articles described herein may be used in microelectronic applications or articles. For example, such microelectronic articles include sintered articles (according to one or more embodiments described herein) comprising a first major surface and a second major surface opposite the first major surface. In one or more embodiments, the microelectronic articles include continuous (e.g., long tapes described herein) or individual (e.g., sheets cut or singulated from the tape) sintered articles. In one or more embodiments, the microelectronic articles include continuous or individual sintered articles having widths of about 1 mm or more, about 1 cm or more, about 5 cm or more, or about 10 cm or more. In one or more embodiments, the microelectronic articles include sintered articles having lengths of about 1 meter or more, about 5 m or more, or about 10 m or more. In one or more embodiments, the microelectronic articles include continuous or individual sintered articles having thicknesses of less than 1 mm, about 0.5 mm or less, about 300 micrometers or less, about 150 micrometers or less, or about 100 micrometers or less. In one or more embodiments, the microelectronic articles include sintered articles having a crystalline ceramic content of about 10% by volume or more, about 25% by volume or more, 50% by volume or more, about 75% by volume or more, or about 90% by volume or more.

[0209] In one or more embodiments, the sintered article includes one or more vias (e.g., holes, apertures, wells, pipes, passages, connections; see hole 1490 in FIG. 53 ) disposed along a given region of the first major surface of the sintered article. In one or more embodiments, the vias extend partially or entirely through the thickness of the sintered article. In one or more embodiments, the vias can be arranged in a pattern that can be repeating or periodic, such as where vias are formed along a tape in a continuous roll-to-roll process and the tape is subsequently singulated to form multiple individual components for semiconductor or other electronic devices. In one or more embodiments, the vias can be spaced apart from one another such that there is a distance of about 0.5 m or less, 10 cm or less, or 5 cm or less between the vias (i.e., at least between some, most, or each via and its nearest neighbor). In some embodiments, this via spacing may be present in sintered articles having thicknesses of less than 1 mm, about 0.5 mm or less, about 300 microns or less, about 150 microns or less, or about 100 microns or less. In one or more specific embodiments, this via spacing may be present in sintered articles having thicknesses of about 50 microns or less. The vias may be cut, for example, by a laser, a mask and etchant, a punch, or other method before, during (e.g., during partial sintering), or after sintering. While forming the vias after sintering can aid in the accuracy of via placement and sizing, the consistency of the processes and materials described herein allows vias to be formed, for example, in green or partially sintered tapes, with precision in placement, sizing, wall geometry, etc., within desired tolerances for certain applications.

[0210] In one or more embodiments, the sintered article includes a conductive layer (e.g., a copper, aluminum, or other conductive layer; see generally layer 1350 in FIG. 47 ) disposed on the first major surface, the second major surface, or both the first and second major surfaces. In one or more embodiments, the conductive layer covers a portion or all of the major surface on which it is disposed, for example, overlapping at least 20%, at least 40%, at least 60%, or at least 80% of each surface. In other words, the conductive layer can form a continuous layer over the entire area of ​​the surface on which it is disposed, or can form a discontinuous layer over the surface on which it is disposed. The conductive layer may form a pattern, which may be repeating or periodic, such as for unsingulated semiconductor components formed on a tape. In one or more embodiments, the sintered article may include one or more additional layers disposed on or between the conductive layer and the sintered article, and / or intermediate the conductive layer and the tape (or other sintered article described herein). Such one or more additional layers may cover a portion or the entire surface on which they are disposed (i.e., the major surface of the sintered article or the conductive layer), for example, according to the percentages described above with respect to the conductive layer. In other words, the one or more additional layers may form a continuous layer over the entire area of ​​the surface on which they are disposed, or may form a discontinuous layer over the surface on which they are disposed. The one or more additional layers may form a pattern, which may be repeating or periodic. In some embodiments, the one or more additional layers may be a conductive layer, a dielectric layer, a sealing layer, an adhesive layer, a surface-smoothing layer, or other functional layer. In some embodiments, the conductive layer, and optionally one or more additional layers, may be present in a sintered article having a thickness of less than 1 mm, about 0.5 mm or less, about 300 micrometers or less, about 150 micrometers or less, about 100 micrometers or less, or about 50 micrometers or less. Accordingly, these layers and the sintered article may be flexible and / or may be wound onto a roll or spool, as described herein.

[0211] In some embodiments, the sintered article may include two or more of a plurality of vias, a conductive layer, and one or more additional layers.

[0212] In one or more embodiments, the system 10 for producing sintered tape articles may include a fabrication system for further processing the green tape, partially sintered article, and / or sintered article described herein for use in a microelectronic article. In one or more embodiments, the fabrication system may be located downstream of the binder burnout furnace 110 but upstream of the sintering station 38 to process binder-free tapes, or after the sintering station 38 to process partially sintered articles, or before the furnace 110 to process green tapes that will be subsequently sintered as described elsewhere herein. In one or more embodiments, the fabrication system may be located downstream of the sintering station 38 but upstream of the intake system 42 to process the sintered articles. In one or more embodiments, the fabrication system may be located downstream of the intake reel 44 but upstream of the reel 48 to process the sintered articles. In one or more embodiments, the fabrication system may be located downstream from the reel 48 to process the sintered articles. In such embodiments, the fabrication system processes the green tape material, partially sintered articles, or sintered articles while they are in a continuous (not discrete) state. Other configurations are possible for processing the sintered articles as discrete articles.

[0213] In one or more embodiments, the fabrication system may expose at least a portion of the green tape material, partially sintered article, or sintered article to a mechanism, such as laser energy or a drill, to form a via. In one or more embodiments, the fabrication system for forming vias using laser energy may include a hugging drum (see generally vacuum drum 25 in FIG. 6 ) having a surface with a curvature that draws the green tape material, partially sintered article, or sintered article to conform to the curvature, thereby facilitating the formation of the via on a major surface of the sintered article. In one or more embodiments, the hugging drum facilitates focusing the laser beam on the major surface of the green tape material, partially sintered article, or sintered article.

[0214] In one or more embodiments, the vias may be formed by mechanical means. For example, the fabrication system may include a flat plate to which the green tape material, the partially sintered article, or a portion of the sintered article is temporarily secured, such that one major surface of the green tape material, the partially sintered article, or the sintered article contacts the flat plate. Transporting the green tape material, the partially sintered article, or the sintered article to the fabrication system may use stepped repetitive motions, accelerations or decelerations, or continuous speeds to enable the portion of the sintered article to be temporarily secured to the flat plate. In one or more embodiments, a vacuum may be used to temporarily secure the green tape material, the partially sintered article, or a portion of the sintered article to the flat plate.

[0215] In one or more embodiments, the fabrication system may form the vias by mechanically separating portions of the green tape material, the partially sintered article, or the sintered article. In one or more embodiments, the fabrication system may include the use of photolithography with a solvent or acid to remove portions of the green tape material, the partially sintered article, or the sintered article. In such embodiments, when the fabrication system is applied to the green tape material or the partially sintered article, the fabrication system may include a control mechanism to control the scaling of the vias and the scaling of the via pattern due to shrinkage when the green tape material or the partially sintered article is fully sintered. For example, the control mechanism may include sensors at the exit of the sintering station 38 that measure the distance between vias and the spacing between vias and feed this information back to the fabrication system for adjustment. For example, if a fabrication system is forming vias with a diameter of approximately 75 micrometers and a distance or pitch between vias of 500 micrometers, and the total sintering shrinkage from the green tape material to the sintered article is assumed to be 25%, the fabrication system will make, or can make, adjustments to form vias in the green tape material with a pitch of 667 micrometers and a diameter of approximately 100 micrometers. If, after processing, the total sintering shrinkage is measured to be 23%, the fabrication system can then make further adjustments to ensure the correct spacing for vias in the green tape material is 649 micrometers to accommodate the total sintering shrinkage of 23%. The vias in some embodiments have a maximum width cross-sectional dimension (coplanar with the surface of the sheet or tape) of at least 250 nm, e.g., at least 1 μm, e.g., at least 10 μm, e.g., at least 30 μm, e.g., at least 50 μm, and / or less than 1 mm, e.g., less than 500 μm, e.g., less than 100 μm. In some embodiments, the vias are filled with a conductive material such as copper, gold, aluminum, silver, alloys thereof, or other materials. The vias may be laser cut, formed with a laser and etchant, mechanically drilled, or otherwise formed, and may be arranged in a repeating pattern along a sheet or tape that can then be singulated into multiple individual electronic device components.

[0216] 104 shows a cross section of an example stackup 810 of ceramic sheets 812 with vias 814 extending to metal layer 815. Fiducials 818 can aid in aligning sheets 812.

[0217] The system 10 described herein provides another method for controlling via spacing during the sintering process. For example, tension in the process direction 14 during sintering can stretch the article being sintered and deflect sintering shrinkage. This tension can increase via spacing in the process direction 14, effectively reducing sintering shrinkage in the process direction 14. Sintering differences are observed in the process direction 14 as opposed to perpendicular to the process direction 14, which can be about 2% to about 3% when tension is applied. Thus, some vias that would otherwise be circular can become oval or oblong.

[0218] The size and shape of the vias can be controlled and adjusted by a combination of sintering shrinkage along the direction parallel to the process direction 14, sintering shrinkage across the direction perpendicular to the process direction 14, tension in these two directions, and the geometry of the sintering station 38, and / or by the use of air bearings to transport the green tape material, partially sintered article, or sintered article during sintering or while at elevated temperatures.

[0219] In one or more embodiments, ceramic material may be added to system 10 at any step to reduce sintering shrinkage. The ceramic material may be added by an inkjet printhead, which can apply the ceramic material uniformly to the porous partially sintered or sintered article while maintaining open porosity. In one or more embodiments, small amounts of ceramic material may be added to the porous partially sintered or sintered article by printing. Laser, photolithography, inkjet, atomic layer deposition, and some printing and other processing methods can be achieved by the inner radius of a curved air bearing or by using a hug drum divided into sections with open areas to expose the partially sintered or sintered article to processing equipment. Thus, a tape or other article as disclosed herein may be comprised of two or more co-fired inorganic materials (e.g., ceramics or phases) or may include a portion comprised of the co-fired inorganic materials, for example, where one of the materials infiltrates or fills the pores of the other material. In contemplated embodiments, the filling / infiltrating material may be chemically identical to the porous material, but may be distinguishable in terms of crystalline content (eg, grain size, phase).

[0220] In one or more embodiments, vias can be formed on a sintered article that has a pattern of conductive layers on one or both sides. One or more conductive layers can be printed or patterned (e.g., screen printed, electroless plated, etc.) after via formation and final sintering. However, in one or more embodiments, one or more conductive layers can also be printed or deposited before final firing of the sintered article. In some sintering processes that sinter only small sheets (e.g., having length and width dimensions of about 20 cm x 20 cm) that are individual pieces (not continuous ribbons), one or more conductive layers are printed after via formation and / or only on the substrate tape. For multilayer substrates, individual substrate tape layers are aligned and laminated, or can be aligned and laminated, with some multilayer substrates using as many as 30-40 substrate tape layers. Alumina with tungsten, molybdenum, or platinum conductors can be co-sintered to form low-firing ceramic packages based on cordierite (glass-ceramic) with copper-based conductors. In some embodiments described herein, one or more conductive layers may be formed (e.g., by printing or deposition) before the final sintering step, and the techniques disclosed herein can assist in controlling the dimensions of the vias and conductor patterns during the sintering step.

[0221] Additionally, the continuous sintering process and system 10 provides a means for controlling the spacing and pattern of vias and the pattern of one or more conductive layers relative to their spacing during the sintering process. Tension in the process direction during sintering can stretch the green tape material, partially sintered article, or sintered article and / or deflect sintering shrinkage, as disclosed above. This tension can increase the spacing and pattern of vias and the pattern of one or more conductive layers in the process direction, effectively reducing sintering shrinkage in the process direction. The variance in sintering in the process direction relative to the direction perpendicular to the process direction can be about 2% to about 3%, for example, where the tape is stretched in the process, i.e., lengthwise, direction.

[0222] A controlled curvature sintering station 38, or curved air bearing, can be used to transport the green tape material, partially sintered article, or sintered article in the process direction 14 and to prevent the green tape material, partially sintered article, or sintered article from having excessive curvature across the width of the green tape material, partially sintered article, or sintered article. If the curvature across the ribbon or sheet is gentle, tension parallel to the process direction can provide some tension perpendicular to the process direction, thereby controlling or limiting distortion.

[0223] Providing tension in a direction perpendicular to the process direction 14 can be difficult, especially at temperatures where the sintered article is plastically deformable and / or sintered and plastically deformable. In such areas of the system 10 (or particularly the sintering station 38), rollers angled away from a direction parallel to the process direction 14 (see, e.g., FIG. 88B) can apply some tension perpendicular to the process direction 14 (e.g., across the width of the tape). This tension can increase the spacing of the vias perpendicular to the process direction 14, which effectively reduces sintering shrinkage perpendicular to the process direction 14.

[0224] Fiducial marks for alignment can be created by laser, mechanical, chemical means, or by slight compositional changes that produce visible results. These marks aid in alignment of further processing steps such as conductor printing, patterning, and / or lamination.

[0225] Another aspect of the present disclosure relates to a multi-layer sintered article having a width of about 1 mm or more, 1 cm or more, 5 cm or more, 10 cm or more, or 20 cm or more, along with a length of 1 meter or more, 3 m or more, 5 m or more, 10 m or more, or 30 m or more, wherein the sintered article has a thickness of less than 1 mm, less than about 0.5 mm, less than about 300 micrometers, less than about 150 micrometers, or less than about 100 micrometers. In one or more embodiments, the sintered article has a crystalline ceramic content of more than 10 volume %, more than 25 volume %, more than 50 volume %, more than 75 volume %, or more than 90 volume %. The article has at least two sintered layers, and may have more than 40 such layers. The layers of the sintered article may have a thickness of 150 micrometers or less, 100 micrometers or less, 75 micrometers or less, 50 micrometers or less, 25 micrometers or less, 20 micrometers or less, 15 micrometers or less, 10 micrometers or less, 5 micrometers or less, and / or at least 3 micrometers, for example. In one or more embodiments, the layers of the sintered article need not be of the same composition, and some of the layers include glass. In some embodiments, such glass layers may include 100% glass, for example, at least 100% amorphous silicate glass.

[0226] In one or more embodiments, the multilayer sintered article includes multiple vias, one or more conductive layers, and / or any additional layers as described above with respect to the microelectronic article.

[0227] In one or more embodiments, the system 10 may include processes and apparatus for producing such multilayer sintered articles. The multiple layers may be produced by casting or web coating multiple layers of green tape material (i.e., including ceramic particles with a polymer binder) onto one another. This multilayer green tape material structure may then be processed through the system 10 described herein. In one or more embodiments, the multilayer green tape material structure may also be formed by sequentially stacking multiple green tapes including ceramic particles at about room temperature and then feeding the stacked tapes into the system 10. The partially sintered articles may also be laminated together in the sintering station 38 using gentle pressure. This pressure may be generated by providing a gentle curvature in the sintering station 38 through which the partially sintered articles are drawn. Each partially sintered article may have its own tensioning and payout rate control. Each partially sintered article may have fiducial marks to aid in article alignment. Tension and payout rate can be used to match sintering shrinkage between articles and align vias and conductors between articles. If the fiducial marks are not aligned when the multilayer article exits the furnace, the payout rate and / or tension of the layers can be adjusted to bring the layers back into alignment. Additional pressure perpendicular to the length and width of the multilayer article can be provided by hot rollers as described above.

[0228] Because the conductors and ceramic materials in a multilayer electrical substrate may not have the same coefficients of thermal expansion, some designs can provide overall stress reduction (balancing) relative to the "bottom" side of the multilayer sintered article with respect to the "top" side. Such designs have equal amounts of metal or ceramic on the top and bottom of the multilayer, for example, by mirroring the layers about a midplane within each lamination. Within the thin ceramic layers, structures where the stress / CTE is not balanced may experience deformation of the ceramic and / or warpage of the entire laminate structure.

[0229] In one or more embodiments, a circuit board for an electronic device comprises a sintered article described herein having conductors patterned thereon. The conductors for the circuit board may be printed directly onto the green tape material, the partially sintered article, or the sintered article, and / or may be printed onto one or more coatings or one or more layers bonded to the green tape material, the partially sintered article, or the sintered article, such as an adhesion-promoting layer, a surface-smoothing layer, and / or other functional layer. Printing can be by: direct screen printing; electroless plating and patterning; lithography; or by using a silicone carrier intermediary between patterning and application of the pattern onto the sintered article by a gravure patterning roller and / or other process.

[0230] Electrical conductors for circuit boards can be printed directly onto the partially sintered article after the intermediate firing step but before final sintering, and / or printed into a coating on the partially sintered article. The porosity of the partially sintered or sintered article can improve adhesion of the conductor print or pattern. Printing can be by: direct screen printing; lithography; or by using a silicone carrier intermediary between patterning and application of the pattern onto the ceramic by a gravure patterning roller or other process.

[0231] One aspect of the process and apparatus may be to use a hugging drum while simultaneously patterning a long, continuous length of porous ceramic ribbon or sheet. The hugging drum pulls the ceramic ribbon or sheet to conform its curvature to the drum's surface, thereby reducing the difficulty of printing the conductor pattern. Photolithography can also be accomplished on a hugging drum, using a solvent or acid to etch or wash away portions of the conductor pattern on the green ribbon or sheet before final sintering. When patterning conductors before final sintering, it is prudent to use a means to control the pattern, size, scaling, or pitch due to sintering shrinkage. Unfortunately, the sintering shrinkage of ceramic ribbons or sheets can vary by 1% or more from green ribbon (or sheet) to green ribbon (or sheet), and sometimes even within a single green ribbon or sheet. One way to ensure accurate spacing of the conductor patterns is to provide a sensor at the exit of the final sintering step to measure the distance between the conductor patterns. This information can be fed to a pattern printing means (e.g., laser, drilling, punch, etching system), photolithography exposure means (e.g., radiation or light source, mask) to adjust the conductor pattern of the ribbon or sheet before final sintering to match the current sintering shrinkage. (The length of the ribbon or sheet between the measuring means and the "patterning" means may not be perfectly accurate, but it can be more accurate than batch sintering using a single kiln or tunnel kiln, where, for example, much of the final product may be lost due to inaccuracies.) Continuous sintering (e.g., roll-to-roll sintering, continuous fired ceramics) offers another means for controlling via spacing during the sintering process. Tension applied during sintering in the web transport direction (i.e., lengthwise relative to the tape) can stretch the article (e.g., ribbon or sheet) being sintered and / or deflect sintering shrinkage. This tension can increase the spacing of the conductor patterns in the ribbon or sheet transport direction, effectively reducing sintering shrinkage in the ribbon transport direction. Differences in sintering in the ribbon transport direction relative to the direction perpendicular to the ribbon transport direction have been observed, up to about 2% to about 3% when tension is applied.

[0232] Photolithography, inkjet, atomic layer deposition, some printing and other processing techniques can be achieved by the inner radius of a curved air bearing or by using a hug drum divided into multiple sections with open areas to expose the ceramic ribbon or tape to conductor patterning processing equipment.

[0233] Alumina with tungsten, molybdenum, or platinum conductors may be co-sintered with other inorganic materials disclosed herein to form low-fire ceramic packages based on cordierite (glass-ceramic) with copper-based conductors.

[0234] The controlled curvature kiln or curved air bearing through or over which the ceramic ribbon or web having the conductor pattern is pulled prevents the ceramic ribbon or sheet having the conductor pattern from having excessive curvature over the shorter length of the ribbon, which in some such embodiments is perpendicular to the ribbon transport direction.

[0235] Providing tension in the direction perpendicular to the ribbon transport direction (cross-web direction) can be difficult, especially at temperatures where the ceramic ribbon bearing the conductor pattern is plastically deformable or sintered and plastically deformable. In the high-temperature zone of the furnace, rollers angled away from the direction parallel to the ribbon transport direction can apply some tension perpendicular to the ribbon transport direction. This tension can increase the spacing of the vias perpendicular to the ribbon transport direction, which effectively reduces sintering shrinkage perpendicular to the ribbon transport direction. The size and pitch of the conductor pattern can be controlled and adjusted by a combination of sintering shrinkage along the direction parallel to the ribbon transport direction (the long length of the ceramic ribbon), sintering shrinkage across the direction perpendicular to the ribbon transport direction, tension in these two directions, and the geometry of the furnace and / or air bearings on which the ceramic ribbon or sheet rests during sintering or at elevated temperatures.

[0236] Fiducial marks for alignment can be created by laser, mechanical, chemical means, or by slight compositional changes that produce visible results. These marks aid in the alignment of further processing steps such as conductor printing, patterning, and lamination.

[0237] Multilayer structures with ceramic and conductors can be bonded at high temperatures from a final sintered conductor and a ceramic sheet or ribbon with fewer layers, or even from a sheet with only a single ceramic and conductor layer.

[0238] Thin circuit boards with ceramic insulator layers benefit from balancing stresses between the top and bottom. This can be achieved by having a patch or pattern of material printed on the opposite side of the desired conductor pattern that can relieve CTE or thermal expansion-related stresses between the conductor and the ceramic (and possibly sintering-related stress differences between the conductor and the ceramic). This can take the form of a second conductor layer of similar thickness and mass of material on the bottom of the board, which balances the CTE-related stresses (and sintering-related stress differences) between the top and bottom, allowing the circuit board to remain mostly flat without warping.

[0239] The thicker the multilayer structure and / or circuit board, the more rigid it will be after full sintering. Winding the article into a small roll with a diameter of 30 to 7.5 mm can be problematic, especially with ceramic and conductor structures with thicknesses of 1 mm, 0.5 mm, and 250 micrometers. Means for cutting the continuously sintered articles by laser, diamond saw, abrasive blast, water blast, and other techniques can be fitted to the continuous sintering machine, for example, where individual structures or groups of structures can be cut into sheets. A cutting device can be added to the exit of the final sintering furnace, where the cutting means moves or contacts the long-length articles, for example, as they exit the furnace.

[0240] 56 and 57, there is shown a process for initiating sintering and threading of the green tape 20A through the binder removal station 34A and the sintering station 38A of a system 1500A for producing a sintered tape article, according to one example embodiment. In general, the system 1500A is substantially identical to and functions similarly to the system 10 described above, except for slightly different and alternative reel placement / positioning within the separation system 12A, tension control system 32A, and intake system 42A.

[0241] To initiate reel-to-reel transfer of the tape material from the source reel 16A to the intake reel 44A, the substrate tape 20A must be threaded through the channels of the binder removal station 34A and the sintering station 38A to connect it to the intake reel 44A, which applies tension to pull the substrate tape through the binder removal station 34A and the sintering station 38A. Similarly, if the tape material breaks during operation of the binder removal station 34A and the sintering station 38A (which may occur after binder removal), the tape material must be threaded through the binder removal station 34A and subsequently the sintering station 38A while these stations are at a sufficient operating temperature. Applicant has determined that threading, particularly when the binder removal station 34A and the sintering station 38A are hot, can be particularly difficult due to the difficulty of threading the unbonded tape 36 (i.e., the free-standing tape material after removal of the organic binder) (shown in FIG. 3 ) through the sintering station 38A after binder removal. Thus, while the discussion of the threading process and system herein primarily relates to threading base tape 20A, it should be understood that the threading process can be used to thread a variety of tape materials, including unbonded tape 36 (shown in FIG. 3) and / or partially sintered tape materials, through a sintering system such as system 10 or system 1500A.

[0242] As described in more detail below, applicant has developed a process that utilizes a threading material or leader to pull the substrate tape 20A through the binder removal station 34A and the sintering station 38A to begin the reel-to-reel process described above. In such an embodiment, the threading material passes through the sintering station 38A and the binder removal station 34A, and the leader is coupled to the substrate tape 20A upstream, or at the entrance, of the binder removal station 34A.

[0243] Tension is then applied to the substrate tape 20A from the intake reel 44A through the leader, beginning the process of moving the substrate tape 20A through the binder removal station 34A and the sintering station 38A. While sintering of the substrate tape can be achieved by various approaches to threading the substrate tape through the binder removal station 34A and the sintering station 38A (e.g., manual threading), Applicant has determined that the leader-based threading process described herein provides high quality / low camber, even at the leading edge of the sintered material. This improved product quality reduces production waste, improves process efficiency by reducing the need for / eliminating handling of cambered sections of the substrate tape, and improves the integrity of the winding of the sintered material on the intake reel 44A due to the consistency of the shape along the length of the sintered tape material. Furthermore, in the context of high temperature threading (e.g., threading where the binder removal station 34A and sintering station 38A are hot), Applicant has discovered that use of the leader-based process described herein provides an efficient method for supporting and pulling the leading edge of a delicate unbonded portion of tape material (e.g., unbonded tape 36 shown in Figure 3 and described above) after it exits the binder removal station 34A until sintering occurs during its passage through the sintering station 38A.

[0244] 56 and 57, the threading material, shown as leader 1502A, is threaded in a reverse direction from the intake reel 44A through the channels of both the sintering station 38A and the binder removal station 34A, such that a first section of the leader 1502A, shown as end section 1504A, is positioned outside the entrance opening 116A of the binder removal station 34A. In this arrangement, as shown in FIG. 56, the leader 1502A is a single continuous piece of material positioned such that the leader 1502A extends the entire distance from the intake reel 44A through the entire sintering station 38A and binder removal station 34A.

[0245] The substrate tape 20A is moved from the source reel 16A (e.g., by unwinding the substrate tape 20A from the reel) toward the entrance opening 116A of the binder removal station 34A, such that the leading end section 1506A of the substrate tape 20A is positioned adjacent to and overlaps the end section 1504A of the leader 1502A. After the leading end section 1506A of the substrate tape 20A and the end section 1504A of the leader 1502A are positioned adjacent to each other, as shown in FIG. 57 , the leading end section 1506A and the end section 1504A of the substrate tape 20A are joined or joined together upstream of the binder removal station (e.g., between the entrance opening 116A of the binder removal station and the source reel 16A in the process direction 14A). This forms a splice or joint at the overlapping section between the leader 1502A and the substrate tape 20A.

[0246] After the leader 1502A is coupled to the substrate tape 20A, a force is applied to a portion of the leader 1502A located outside (e.g., downstream) of the binder removal station 34A and the sintering station 38A, thereby pulling the leader 1502A and substrate tape 20A in the process direction 14A through the binder removal station 34A and the sintering furnace 38A. In the specific embodiment shown in Figure 56, a second or downstream end 1508A of the leader 1502A is coupled to the intake reel 44A, and the force generated by rotation of the intake reel 44A provides the force to move / pull the leader 1502A and substrate tape 20A through the binder removal station 34A and the sintering furnace 38A. In some embodiments, Applicant has discovered that a processing speed (e.g., the speed at which the tape material is moved through the system 1500A) of approximately 3 inches (7.62 cm) per minute is used during the threading process, and that this speed can be increased to approximately 6 inches (15.24 cm) per minute for the sintering process after the joint between the leader 1502A and the base tape 20A passes through the binder removal station 34A and the sintering furnace 38A.

[0247] Thus, the use of the leader 1502A allows the downstream, or rewind, side of the system 1500A to first connect to the upstream, or unwind, side of the system 1500A, thereby initiating reel-to-reel sintering of the substrate tape 20A material. Furthermore, by providing such initial threading of the binder removal station 34A and the sintering station 38A through the same connection between the unwinding system and the intake system that advances the substrate tape 20A during the sintering process, the leader-based threading process described herein can establish the proper tension and speed along the entire length of the substrate tape 20A passing through the binder removal station 34A and the sintering station 38A (including the leading end section 1506A of the substrate tape 20A in the overlapping position). Furthermore, by providing horizontal traction through the leader 1502A, the leader-based process described herein can achieve threading through the horizontally oriented channels of the binder removal station 34A and the sintering station 38A. This can be difficult, especially given the delicate nature of the tape material after binder removal.

[0248] As previously described in detail with respect to system 10, heating the binder removal station 34A removes or burns off the binder from the substrate tape 20A, and heating the sintering station 38A causes sintering of the inorganic material of the substrate tape 20A. In one potential application of the threading process described herein, the binder removal station 34A and / or the sintering station 38A are already at their respective operating temperatures when threading the leader 1502A. This would be the case if the leader 1502A were used to thread the substrate tape 20A after material breakage during reel-to-reel sintering. In another potential application of the threading process described herein, the binder removal station 34A and / or the sintering station 38A are cold (e.g., below their respective operating temperatures, off at room temperature, etc.) when threading the leader 1502A. This would be the case if the leader 1502A were used to thread the substrate tape 20A during initial startup of the system 1500A.

[0249] As described in more detail above, after the initial movement of the joint or overlap between the leader 1502A and the leading end section 1506A of the substrate tape 20A through the debinder station 34A and sintering furnace 38A, the substrate tape 20A is continuously unwound from the source 16A and moved through stations 34A and 38A to form a length of sintered material, as described above. After sintering, the sintered material is wound onto the intake reel 44A. In one embodiment, the leader 1502A is disconnected from the sintered tape material after the leading end section 1506A of the substrate tape 20A exits the sintering station 38A and before the sintered tape material is wound onto the intake reel 44A. In another embodiment, the leader 1502A is wound onto the intake reel 44A along with the sintered tape material, which forms the innermost layer of the reel containing the sintered material.

[0250] In various embodiments, the leader 1502A is an elongated, flexible piece of material capable of withstanding the high temperatures of the binder removal station 34A and the sintering station 38A. In the joining process shown in FIG. 57 , the leading end section 1506A of the substrate tape 20A overlaps the end section 1504A of the leader 1502A to form an overlapping section 1512A. In this arrangement, the lower surface of the substrate tape 20A faces and contacts the upper surface of the leader 1502A. In this arrangement, by positioning the substrate tape 20A on top of the leader 1502A, the leader 1502A functions to support the leading end section 1506A of the substrate tape 20A through the binder removal station 34A and the sintering furnace 38A.

[0251] In some embodiments, adhesive material 1510A is used to form a bond joining leader 1502A to substrate tape 20A. As shown in Figure 57, in some such embodiments, adhesive material 1510A is disposed on the upper surface of leader 1502A and forms a bond to the lower surface of substrate tape 20A. As described in more detail below, in various embodiments, Applicant has determined that matching various properties (e.g., the coefficients of thermal expansion (CTE)) of the materials forming the adhesive 1510A, leader 1502A, and base tape 20A facilitates maintaining the bond between the leader 1502A and the tape material, particularly during passage through the high temperatures of sintering station 38A. Furthermore, a strong bond between the leader 1502A and base tape 20A allows a desired level of tension to be applied to the leader 1502A and transmitted through the bond to the base tape 20A provided by the adhesive 1510A. As described herein, Applicant has discovered that applying a small (e.g., gram-level) but consistent tension to the tape material during sintering reduces warpage that may form across the width of the tape during sintering.

[0252] In various embodiments, Applicant has determined that the volume of adhesive material 1510A used and the shape of the adhesive material 1510A applied to the leader 1502A affect the properties of the bond formed between the leader 1502A and the substrate tape 20A. In a specific embodiment, the volume of adhesive material 1510A is small (e.g., about 0.1 mL of an alumina-based adhesive). In one embodiment, the adhesive 1510A is used to bond the leader 1502A to the unsintered substrate tape material 20A, and in such an embodiment, Applicant has found that circular dots of adhesive 1510A work well. Applicant hypothesizes that this circular geometry aids in distributing thermal and mechanical stresses induced by cement and tape shrinkage and CTE mismatch (if any) between the materials of the leader 1502A, adhesive 1510A, and substrate tape 20A. In another embodiment, adhesive 1510A is used to bond leader 1502A to the partially sintered material, and in such an embodiment, Applicant believes that a line of adhesive 1510A extending across the width of leader 1502A works well. Applicant hypothesizes that this linear geometry acts to apply uniform compression to the web as it moves through the sintering station.

[0253] In a specific embodiment, the binder removal station 34A operates to remove liquid and / or organic components from the adhesive 1510A (and from the substrate tape 20A) as the overlap section 1512A between the leader 1502A and the substrate tape 20A traverses the binder removal station 34A. Applicant believes that various properties of the adhesive material 1510A and the substrate tape 20A contribute to the likelihood that the binder formed by the adhesive material 1510A will break down during passage through the binder removal station 34A and the sintering station 38A. Applicant hypothesizes that the temperature profile through the binder removal station 34A may soften or even melt the organic material in the substrate tape 20A before it is released from the tape, thereby helping to limit the intensity of stresses around the cement joint as the individual components begin to change shape / size due to contraction and thermal expansion. Applicant hypothesizes that "deforming" or reshaping the substrate tape around the location of adhesive 1510A before it loses its elasticity / plasticity can help reduce defects and improve the quality of the bond formed by adhesive 1510A. This elasticity / plasticity can also allow adhesive 1510A to wick away liquids and organic materials that can cause a buildup of pressure between leader 1502A and substrate tape 20A. This buildup of pressure can cause the bond to fail, or the buildup of gas can rupture substrate tape 20A.

[0254] In specific embodiments, the tension applied during the process of pulling the overlap section or joint between the leader 1502A and the substrate tape 20A can vary and / or increase as the overlap section 1512A passes through the binder removal station 34A and / or the sintering station 38A. In one specific embodiment, a low level of tension, e.g., less than 25 grams, is initially applied while the overlap section 1512A passes through the binder removal station 34A, and then the tension is increased as the overlap section 1512A passes through the sintering station 38A. In one specific embodiment, a tension of approximately 25 grams or more is applied after the overlap section 1512A and adhesive material 1510A reach the center of the sintering station 38A. Applicant believes that the tension at this point can be increased without separating the bond between the leader 1502A and the substrate tape 20A because sintering of the material of the substrate tape 20A has occurred at this point. Applicant believes that applying high levels of tension too quickly, before strength has had a chance to develop, will generally lead to failure of the bond formed by adhesive 1510A.

[0255] In various embodiments, the bond and / or support between the leader 1502A and the substrate tape 20A is enhanced by varying levels of overlap between the leader 1502A and the substrate tape 20A. As can be seen in FIG. 57, the greater the overlap between the leader 1502A and the substrate tape 20A, the greater the amount of support provided by the leader 1502A to the substrate tape 20A. Similarly, the level of overlap between the leader 1502A and the substrate tape 20A is related to the amount of frictional interlocking between the leader 1502A and the substrate tape 20A, which can supplement the bond provided by the adhesive 1510A. In embodiments utilizing an adhesive 1510A, applicants have found that an overlap section 1512A having a length of 1 to 5 inches (2.54 to 12.7 cm), measured in the process direction 14A, works well. In some embodiments, the connection between the leader 1502A and the substrate tape 20A may be provided by friction alone (e.g., without adhesive 1510A), in which case the length of the overlap section 1512A in the process direction 14A may be greater than 5 inches (12.7 cm), for example, greater than 10 inches (25.4 cm), between 10 inches (25.4 cm) and 30 inches (76.2 cm), about 24 inches (60.96 cm), etc.

[0256] In various embodiments, Applicant has identified numerous material combinations for the leader 1502A, substrate tape 20A, and adhesive 1510A that provide the threading characteristics / functionality described herein. Generally, the leader 1502A is formed from a material that differs in at least one aspect from the substrate tape 20A. In some such embodiments, the leader 1502A is formed from the same material type as the inorganic grains of the substrate tape 20A, but has a different (e.g., higher) degree of sintering than the inorganic material of the substrate tape 20A. In some such embodiments, the leader 1502A is an elongated tape of sintered ceramic material, and the substrate tape 20A supports unsintered or less sintered grains of the same type of ceramic material.

[0257] In some other embodiments, leader 1502A is formed from an inorganic material that is different from the material type of the inorganic particles of substrate tape 20A. In one specific embodiment, leader 1502A is formed from a ceramic material type that is different from the ceramic material type of the inorganic particles of substrate tape 20A. In some other embodiments, leader 1502A is formed from a metallic material, while the inorganic particles of substrate tape 20A are a ceramic inorganic material.

[0258] Applicant has discovered that the coupling configuration shown in FIG. 57 and described herein provides a level of coupling between the leader 1502A and the substrate tape 20A that allows for good transfer of force / tension from the leader 1502A to the substrate tape 20A without a significant risk of debonding. Applicant has further discovered that the risk of debonding and warping during sintering can be reduced by selecting materials for the leader 1502A, adhesive 1510A, and inorganic particulate material of the substrate tape 20A that have relatively similar coefficients of thermal expansion (CTE). In various embodiments, the CTE of the material of the leader 1502A is within ±50 percent of the CTE of the inorganic material of the substrate tape 20A, specifically within ±40 percent of the CTE of the inorganic material of the substrate tape 20A, and more specifically within ±35 percent of the CTE of the inorganic material of the substrate tape 20A. Similarly, in various embodiments, the CTE of the material of the reader 1502A is within ±50 percent of the CTE of the adhesive material 1510A, specifically within ±40 percent of the CTE of the adhesive material 1510A, and more specifically within ±35 percent of the CTE of the adhesive material 1510A.

[0259] The leader 1502A can be formed from a variety of suitable materials. In some embodiments, the leader 1502A is formed from a sintered ceramic material, while in other embodiments, the leader 1502A is formed from a metallic material. In some embodiments, Applicant has discovered that using a porous ceramic material for the leader 1502A improves the ability of the adhesive material 1510A to bond to the leader 1502A. Applicant believes that the porosity of the leader 1502A allows the adhesive material 1510A to bond more easily than if the leader had a less porous or polished surface. In specific embodiments, the leader 1502A can be a platinum ribbon or a fully sintered ceramic material, such as alumina or yttria-stabilized zirconia (YSZ).

[0260] In a specific embodiment, the leader 1502A is sized to allow for handling and bonding to the substrate tape 20A. In a specific embodiment, the leader 1502A has a width that approximately matches (e.g., ±10%) the width of the substrate tape 20A. In a specific embodiment, the leader 1502A has a thickness between 5 μm and 500 μm, more specifically, a thickness in the range of 20 μm to 40 μm. Furthermore, the leader 1502A has a length sufficient to extend from the intake reel 44A through both the sintering station 38A and the binder removal station 34A, and therefore the length of the leader 1502A varies with the size of the system 1500A.

[0261] 56 and 57 generally depict the leader 1502A as a long, thin, flat section of sintered ceramic material, the leader 1502A can take other shapes. For example, in one embodiment, the leader 1502A can be a ceramic board with a long platinum wire cemented to a substrate tape. In another embodiment, the leader 1502A can be a length of ceramic fiber rope or strand.

[0262] The adhesive material 1510A can be formed from a variety of suitable materials. In some embodiments, the adhesive material 1510A is a ceramic adhesive material. In a specific embodiment, the adhesive material 1510A is an alumina-based adhesive material, such as Alumina-Based Adhesive #C4002 available from Zircar Ceramics.

[0263] 58-65, various systems and processes for longitudinally or lengthwise bending of unbonded tape 36B during sintering are shown and described. Overall, Applicant has determined that one of the unanticipated challenges in sintering wide, thin, continuous lengths of unbonded tape 36B is ensuring that the final sintered tape 40B has a high level of cross-width flatness. A high level of cross-width flatness is desirable when using the sintered tape materials described herein in many applications, such as substrates for thin film circuitry, thick film circuitry, solid-state lithium ion batteries, etc.

[0264] Some continuous tape sintering processes may be susceptible to certain flatness distortions (e.g., cross-width bending, edge wrinkling, bubble formation, etc.) that are believed to be caused by the generation of in-plane stresses within the tape material during sintering. For example, Applicant has discovered that various factors, such as variations in ceramic particle density in unbonded tape 36B, large temperature differences within the tape material along the length of the system (e.g., which can exceed 1000°C due to the continuous nature of the systems and processes described herein), and processing speed, contribute to the generation of in-plane stresses during sintering, which can induce buckling unless opposing forces are applied in a manner that allows for the release of these in-plane stresses.

[0265] For example, an alumina tape undergoing continuous sintering with the systems described herein may simultaneously have regions at room temperature and regions at maximum sintering temperature. There may also be regions of tape where the sintering process begins and where shrinkage is minimal, and regions where shrinkage is nearly complete, with shrinkage greater than 8% or even 10% relative to a straight line. Shrinkage and temperature gradients can cause complex biaxial stresses that can induce distortions, such as warping and wrinkling, even in tapes with a certain level of flatness entering the sintering station. These distortions can then become fixed in the sintered tape after cooling, thereby limiting its potential uses.

[0266] As described in more detail below, applicants have determined that stresses that can cause flatness distortions can be at least partially offset by inducing a lengthwise or longitudinal bending in the tape during sintering. During sintering, the tape material plastically relaxes and deforms into the shape of the induced lengthwise bending, which generates forces within the tape material that tend to reduce in-plane stresses that may develop, resulting in the production of sintered tapes with high levels of cross-width flatness. Applicants believe that by utilizing a longitudinal bending during sintering, they can produce flatter sintered tapes despite variations in the particle density of the green tape and high production rates.

[0267] Furthermore, in at least some embodiments, the planarization processes described herein produce flat, thin sintered articles while avoiding / limiting surface contact and resulting surface defects and scratches that are common in contact / pressure-based planarization devices, such as those that can occur when pressing material between cover plates during sintering. As described below, Applicant has developed numerous systems and processes for inducing longitudinal bending that leaves at least one major surface of the tape untouched during sintering, as well as several processes that leave both the upper and lower (major) surfaces of the tape untouched during sintering. Applicant believes that other ceramic sintering processes cannot achieve the high level of cross-width flatness in a continuous sintering process or with the limited degree of surface contact provided by the systems and processes described herein.

[0268] Referring to FIG. 58, a process and system for producing a sintered continuous tape having high flatness is shown. Specifically, FIG. 58 illustrates a system 1600B for producing a sintered tape article according to one exemplary embodiment. Generally, system 1600B is identical to and functions similarly to system 10 described above, except that system 1600B includes a sintering station 38B that includes a bending system 1602B disposed within sintering station 38B. Generally, bending system 1602B is configured or arranged to induce a radius of curvature along the length or longitudinal axis of unbonded tape 36B while tape 36B is being sintered at high temperatures (e.g., greater than 500°C) within sintering station 38B. Applicant has determined that inducing a longitudinal curvature in the tape material by bending during sintering can improve the cross-width shape of the final sintered tape 40B according to the mechanisms described herein.

[0269] In the specific embodiment shown in FIG. 58, the bending system 1602B includes an upwardly convex curved surface 1604B that defines at least a portion of the lower channel surface through the sintering station 38B. The upwardly convex curved surface 1604B defines at least one radius of curvature, designated R1B, which in the specific embodiment is or includes a radius of curvature in the range of 0.01 m to 13,000 m. Generally, as the unbonded tape 36B moves through the sintering station 38B as described above, gravity and / or traction forces within the tape cause the tape to bend to at least partially conform to the curved surface 1604B, which induces longitudinal bending in the tape during sintering at elevated temperatures. In a specific embodiment, the tension applied to the unbonded tape 36B is at least 0.1 grams force per inch (2.54 cm) of linear width of the unbonded tape 36B, and the unbonded tape 36B moves through the sintering station 38B at a rate of 1 inch (2.54 cm) to 100 inches (254 cm) of tape length per minute.

[0270] As shown in Figure 58, the curved surface 1604B curves about an axis parallel to the width axis of the unbonded tape 36B (and perpendicular to the viewing plane of Figure 58). Thus, in such an embodiment, the unbonded tape 36B follows a path through the sintering station 38B generally defined by the channel 104B, with the convex curved surface 1604B defining a curved section of that path through the sintering station 38B. This bending is induced in the unbonded tape 36B by molding to conform to the curved surface 1604B as the unbonded tape 36B passes through the curved section of the path defined by the convex curved surface 1604B.

[0271] In the specific embodiment shown in FIG. 58, the curved surface 1604B forms a continuous curved surface having a single radius of curvature that extends the entire length of the channel 104B between the entrance and exit of the sintering station 38B. In such an embodiment, the radius of curvature of the surface 1604B needed to achieve a sufficient level of bending and extend the entire length of the sintering station 38B, which can vary depending on the length of the sintering station. Thus, for a given maximum prominence H1B of the curved surface 1604B (shown in FIG. 60), a shorter sintering station 38B may have a smaller R1B than a longer sintering station 38B. As a specific example, a sintering station 38B having a length (at least) of 1 meter may have a curved surface 1604B having an R1B between 1 meter and 130 meters. As a specific example, a sintering station 38B having a length (at least) of 3 meters may have a curved surface 1604B having an R1B between 10 meters and 1130 meters. As a specific example, a sintering station 38B that is (at least) 6 m long may have a curved surface 1604B with an R1B of 40 m to 4500 m. As a specific example, a sintering station 38B that is (at least) 10 m long may have a curved surface 1604B with an R1B of 120 m to 13,000 m. In such an embodiment, regardless of length, H1B may be between 1 mm and 10 cm, resulting in the R1B ranges shown above.

[0272] As described above with respect to system 10, sintering station 38B is disposed such that a plane intersecting the entrance and exit of the sintering station forms an angle of less than 10° with the horizontal. As noted above, this generally horizontal sintering configuration allows unbonded tape 36B to move through sintering station 38B in a generally horizontal position. In such an embodiment, curved surface 1604B defines the lower surface of the path traversed by tape 36B between the entrance and exit of sintering station 38B. Applicant believes that this horizontal sintering configuration (described above as reducing airflow-based thermal gradients), combined with forming a longitudinally curved shape in the tape during sintering, can and / or may produce sintered tape having the high level of flatness described herein at much higher speeds than other sintering systems. While Applicant believes that the combination of bending during sintering and a horizontal sintering station 38B provides a high level of flatness, it should be understood that in other embodiments, sintering station 38B may be disposed at any angle between horizontal and vertical. In such non-level embodiments, the dimensions and positioning of curved surface 1604B may be sufficient to achieve the desired level of flatness.

[0273] As shown in FIG. 58 , in a processing configuration of this system 1600B, a continuous length of tape material, such as unbonded tape 36B, is moved into a heating station, such as sintering station 38B. In this configuration, a portion of the continuous tape, shown as unbonded tape 36B, is located upstream of an entrance 106B to sintering station 38B. After sintering, a sintered portion of the continuous tape, such as sintered tape 40B, is located downstream of an exit 108B of sintering station 38B. As is generally understood, at any given time, the continuous tape includes a third portion of tape that is currently being sintered within sintering station 38B. This third portion of the continuous tape is located between the unbonded, unsintered tape 36B upstream of sintering station 38B and the sintered portion of the continuous tape 40B downstream of sintering station 38B. The currently sintered portion of the continuous tape, shown as tape portion 1606B, is located within sintering station 38B as it is heated to a desired sintering temperature (e.g., a temperature above 500° C.).

[0274] Generally, tape portion 1606B has decreasing porosity and increasing degree of sintering in the process direction (e.g., from right to left in the orientation of FIG. 58). As shown in FIG. 58, tape portion 1606B is bent to conform to upwardly facing convex curved surface 1604B, causing tape portion 1606B to generally conform to a curved shape having a radius of curvature corresponding to R1B. As described above, tape portion 1606B can be bent to conform to upwardly facing convex curved surface 1604B by applying longitudinal tension to the continuous tape.

[0275] As can be generally understood from the above description of the unwinding and intake portions of system 10, system 1600B provides for continuous reel-to-reel processing of a long continuous length of tape. In this manner, the entire continuous length of tape to be processed can be moved sequentially through sintering station 38B, such that the entire continuous length of tape to be processed is bent to curvature R1B of upwardly facing convex surface 1604B during its passage through sintering station 38B.

[0276] Referring to FIG. 59, a detailed view of a sintering station 38B including a bending system 1602B according to an exemplary embodiment is shown. In the embodiment shown in FIG. 59, the sintering station channel 104B is partially defined by a tube 1608B (such as the alumina tube described above). In this embodiment, the upward convex surface 1604B is defined by the upward surface of a component or insert 1610B disposed within the tube 1608B. As shown in FIG. 59, the length of the component 1610B is at least 80%, specifically at least 90%, more specifically at least 95% of the length of the channel 104B. In some embodiments, the length of the component 1610B is greater than the length of the channel 104B, whereby the incoming and outgoing sections of the tape are supported on the upward convex surface 1604B when entering and exiting the sintering station 38B.

[0277] As generally understood, in various embodiments, the radius of curvature defining the continuous convex surface 1604B is a function of the maximum elevation H1B and the longitudinal length L2B (e.g., the distance in the horizontal direction of FIG. 60) of the surface 1604B. In a specific embodiment where the convex surface 1604B extends over the entire length of the sintering station 38B, the longitudinal length of the surface 1604B is substantially the same as the longitudinal length of the sintering station 38B. Thus, in such an embodiment, the radius of curvature R1B of the convex surface 1604B is defined as R1B = H1B+(L2B^2) / H1B, and in various embodiments, 0.1 mm < H1B < 100 mm, and 0.1 m < L2B < 100 m. In other possible embodiments, only a portion of the component 1610B forms an arc, and the surface may have another geometric shape having a radius of curvature or a maximum radius of curvature (among more complex geometric shapes) within the range disclosed herein with respect to R1B of the component 1610B.

[0278] In a specific embodiment, the insert 1610B is removable from the channel 104B and is removably coupled to or removably supported by the tube 1608B. In such an embodiment, this allows multiple different inserts 1610B having different curved surfaces 1604B to be positioned within the sintering station 38B to provide the particular bend radius needed to provide the desired level of flattening for a particular process or tape material type, thickness, sintering rate, etc.

[0279] 60 , in various embodiments, the lower surface of channel 104B through sintering station 38B is defined by an upwardly convex curved surface 1604B, and the upper surface of channel 104B is defined by a downwardly concave curved surface 1612B. In specific embodiments, the radius of curvature of downwardly concave curved surface 1612B generally matches (e.g., within 1%, within 10%, etc....

Claims

1. 1. A sintered article comprising: a first major surface; a second main surface opposite the first main surface; a body extending between the first major surface and the second major surface and comprising a sintered ceramic; the first major surface and the second major surface have a grain profile including grains of the sintered ceramic having heights of 25 nm to 150 μm relative to recesses in each major surface at boundaries between grains; the body has a thickness defined as the distance between the first major surface and the second major surface, the thickness being in the range of 3 μm to 1 mm; the body has a width defined as a first dimension of the first major surface perpendicular to the thickness, the width being greater than 40 mm; and The sintered article wherein the body can be flattened without fracture such that the body overlaps or is within 0.05 mm of a flat surface, as determined by pressing the body between two rigid parallel surfaces at 23°C.

2. The sintered article of claim 1 , wherein the body has a porosity of less than 10% by volume.

3. The sintered article of claim 1 , wherein the width is greater than 125 mm.

4. The sintered article of claim 1 , wherein the body is a ceramic ribbon and the body has a length of 10 m or more.

5. 10. The sintered article of claim 1, having a roughness of about 1 nm to about 10 μm over a distance of 1 cm along its length.

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