Photocurable ceramic slurry and temperature-controlled components manufactured therefrom

Abstract

The present invention provides a slurry that accelerates the curing of a photocurable slurry, a method for producing ceramic parts from a photocurable slurry, a vacuum wafer chuck, and a thermal management apparatus. [Solution] The present disclosure relates to a photocurable ceramic slurry comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant, wherein the dispersant facilitates light penetration and curing of the photocurable slurry. Temperature control components manufactured from the slurry include a vacuum wafer chuck having an internal water-cooled channel and a microcooler thermal control device having an internal channel and pins.

Description

Technical Field

[0001] The present disclosure generally relates to photocurable ceramic slurries, methods of fabricating ceramic parts from photocurable ceramic slurries, and ceramic parts fabricated by such methods.

Background Art

[0002] Reaction-bonded ceramic parts containing internal features are important to the semiconductor industry. Examples of parts include, but are not limited to, water-cooled wafer tables, water-cooled condenser mirrors, water-cooled high-energy laser mirrors, and water-cooled microcooler systems for electronic devices. Conventional members can be made by forming a preform piece / section (e.g., two preform halves) having a surface feature (e.g., a channel), bonding the preform pieces with a silicon carbide (SiC)-based paste or adhesive (a material such as a caulking compound), and performing a heat treatment (e.g., ceramic firing, reaction bonding, etc.) to obtain a finished part with an integral ceramic body having an internal feature.

[0003] During the above-described conventional preform bonding operation, a small bead of excess SiC-based paste may be extruded into a feature such as a channel and become part of the finished part. If the size of the channel or other feature is large (5 - 10 mm), the excess paste does not pose a problem. However, many next-generation designs have ultra-small feature sizes (e.g., <1 mm; in some embodiments, 0.25 - 1.0 mm, or 0.5 - 1.0 mm). Beads of excess paste can restrict flow or even clog this small-sized feature, making it difficult to fabricate members having ultra-small features.

[0004] Reaction-bonded pieces can be glass-bonded to avoid the problem of excess paste, but this type of bonding has insufficient corrosion resistance, insufficient thermal conductivity, insufficient electrical conductivity, and / or insufficient strength at elevated temperatures. It can also result in failure when high-temperature, post-treatment is required.

Summary of the Invention

[0005] Therefore, an improved method for manufacturing parts with fine internal shapes that are bonded by reaction is desired. [Means for solving the problem]

[0006] Therefore, the object of this disclosure is to provide a photocurable ceramic slurry for manufacturing ceramic components that overcome some or all of the drawbacks identified above.

[0007] In non-limiting embodiments or aspects, a photocurable ceramic slurry is provided, comprising 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant, wherein the dispersant facilitates light penetration and curing of the photocurable slurry.

[0008] In some non-limiting embodiments or aspects, the slurry may further contain 0-5% by weight of a photoinitiator.

[0009] In some non-limiting embodiments or aspects, the opaque ceramic particles may be selected from the group consisting of silicon carbide, boron carbide, silicon nitride, and titanium diboride. In some non-limiting embodiments or aspects, the opaque ceramic particles may have an average particle size of about 5 to 30 μm.

[0010] In some non-limiting embodiments or aspects, the slurry may further contain elemental silicon.

[0011] In some non-limiting embodiments or aspects, the photocurable resin may include a UV digital light-treated resin.

[0012] In some non-limiting embodiments or aspects, the slurry may have a viscosity of about 1,000 to 30,000 cps at temperatures in the range of about 20 to 50°C.

[0013] In some non-limiting embodiments or aspects, the dispersant causes the slurry to have a light transmission depth of approximately 25 μm or more.

[0014] A method for producing a ceramic component from a photocurable slurry is also provided, in a non-limiting embodiment or manner, comprising: placing a photocurable slurry into a photocurable resin tank; irradiating the slurry with light to react a portion of the slurry and form a preform ceramic component; and bonding the preform ceramic components by reaction to obtain a ceramic component. The photocurable slurry may comprise: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0015] In some non-limiting embodiments or aspects, the method may be carried out using a digital optical processing 3D printer.

[0016] In some non-limiting embodiments or aspects, irradiating the slurry with light may include using an ultraviolet (UV) light source to provide UV light to a portion of the slurry in a photocuring resin tank, the UV light being provided at a wavelength of approximately 300–450 nm.

[0017] In some non-limiting embodiments or aspects, the method may further include: projecting a two-dimensional image of each layer of the preformed ceramic component; and curing each layer of the preformed ceramic component using an ultraviolet light source to form the preformed ceramic component.

[0018] In some non-limiting embodiments or aspects, one or more layers of the preform ceramic component may include a surface shape that includes channels or grooves. In some non-limiting embodiments or aspects, the size of the channels or grooves may range from about 0.2 to 5 mm in length, width, and / or depth.

[0019] In some non-limiting embodiments or aspects, the method may further include: removing any unreacted slurry from the preform ceramic component.

[0020] In some non-limiting embodiments or aspects, the method may further include: thermally decomposing a preformed ceramic component to convert any resin into carbon.

[0021] In some non-limiting embodiments or aspects, bonding by reaction may include Si penetration.

[0022] In some non-limiting embodiments or aspects, the reaction-bonded ceramic components may include silicon carbide, boron carbide, pure carbon, silicon nitride, and / or titanium diboride.

[0023] In a non-limiting embodiment or aspect, a vacuum wafer chuck is also provided, comprising a body, an internal channel having a length, width, and depth in the range of about 0.2 to 5 mm, and a separation pin for supporting a semiconductor wafer, the separation pin being at least partially located within the body, wherein the body and the pin are formed from a photocurable ceramic slurry comprising: 50 to 70% by weight of opaque ceramic particles; 30 to 50% by weight of a photocurable resin; and 0.3 to 1% by weight of a dispersant.

[0024] In some non-limiting embodiments or aspects, a thermal control device is also provided, comprising a ceramic body and a network structure of channels defined on the surface of the ceramic body, wherein the ceramic body is formed from a photocurable ceramic slurry comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant. In some non-limiting embodiments or aspects, the ceramic body may also contain silicon carbide and / or boron carbide.

[0025] According to non-limiting embodiments or aspects: A thermal management device including a ceramic body and a network structure of internal channels and / or chambers within the ceramic body, wherein the ceramic body is formed from a photocurable ceramic slurry comprising: 50 to 70 wt% opaque ceramic particles; 30 to 50 wt% photocurable resin; and 0.3 to 1 wt% dispersant. In some non-limiting embodiments or aspects, the ceramic body may include silicon carbide and be formed by digital light processing 3D printing. In some non-limiting embodiments or aspects, the size of the channels or chambers can range from about 0.2 to 5 mm in length, width, and / or depth.

[0026] Further embodiments or aspects are set forth in the following numbered clauses:

[0027] Clause 1: A photocurable ceramic slurry comprising 50 to 70 wt% opaque ceramic particles; 30 to 50 wt% photocurable resin; and 0.3 to 1 wt% dispersant, wherein the dispersant promotes light penetration to cure the photocurable slurry.

[0028] Clause 2: The slurry of Clause 1, further comprising 0 to 5 wt% photoinitiator.

[0029] Clause 3: The slurry of Clause 1 or 2, wherein the opaque ceramic particles are selected from the group consisting of silicon carbide, boron carbide, silicon nitride, and titanium diboride.

[0030] Clause 4: The slurry of any one of Clauses 1 to 3, wherein the opaque ceramic particles have an average particle size of about 5 to 30 μm.

[0031] Clause 5: The slurry of any one of Clauses 1 to 4, further comprising elemental silicon.

[0032] Clause 6: The slurry of any one of Clauses 1 to 5, wherein the photocurable resin includes an ultraviolet digital light processing resin.

[0033] Clause 7: A slurry according to any of Clauses 1 to 6, having a viscosity of approximately 1,000 to 30,000 cps at temperatures in the range of 20 to 50°C.

[0034] Clause 8: A slurry according to any of Clauses 1 to 7, wherein the dispersant provides a light transmission depth of approximately 25 μm or more.

[0035] Clause 9: A method for producing a ceramic component from a photocurable slurry, comprising: placing a photocurable slurry into a photocurable resin tank; irradiating the slurry with light to react a portion of the slurry and form a preform ceramic component; and bonding the preform ceramic component by reaction to obtain a ceramic component. The photocurable slurry may contain: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0036] Clause 10: The method of Clause 9, carried out using a digital optical processing 3D printer.

[0037] Clause 11: Irradiating the slurry with light: The method of Clause 9 or 10, comprising using an ultraviolet (UV) light source to provide UV light to a portion of the slurry in a photocuring resin tank, wherein the UV light is provided at a wavelength of approximately 300-450 nm.

[0038] Clause 12: Any method of Clauses 9 to 11, further comprising: projecting a two-dimensional image of each layer of the preformed ceramic component; and curing each layer of the preformed ceramic component using an ultraviolet light source to form the preformed ceramic component.

[0039] Clause 13: Any method of Clauses 9 to 12 wherein one or more layers of the preformed ceramic component include a surface shape including channels or grooves.

[0040] Clause 14: Any method of Clauses 9-13, wherein the size of the channel or groove is in the range of approximately 0.2-5 mm in length, width, and / or depth.

[0041] Clause 15: Any method of Clauses 9-14, further comprising removing any unreacted slurry from the preform ceramic component.

[0042] Clause 16: Any method of Clauses 9-15, further comprising thermally decomposing a preformed ceramic component to convert any resin into carbon.

[0043] Clause 17: Any method of Clauses 9 to 16, wherein the bonding by reaction includes Si penetration.

[0044] Clause 18: Any method of Clauses 9 to 17, wherein the ceramic components bonded by reaction include silicon carbide, boron carbide, pure carbon, silicon nitride, and / or titanium diboride.

[0045] Clause 19: A vacuum wafer chuck comprising a body and a separation pin for supporting a semiconductor wafer, the separation pin being at least partially located within the body, wherein the body and the pin are formed from a photocurable ceramic slurry comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0046] Clause 20: A thermal control device comprising a ceramic body and a network structure of channels defined on the surface of the ceramic body, wherein the ceramic body is formed from a photocurable ceramic slurry comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0047] Clause 21: A thermal control device according to Clause 20, wherein the ceramic body contains silicon carbide and / or boron carbide.

[0048] Clause 22: A thermal control device comprising a ceramic body and a mesh structure of internal channels and / or chambers within the ceramic body, wherein the ceramic body is formed from a photocurable ceramic slurry comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0049] Clause 23: The thermal control device of Clause 20, wherein the ceramic body contains silicon carbide and is formed by digital photoprocessing 3D printing.

[0050] Clause 24: In some non-limiting embodiments or aspects, the thermal control device of Clause 20, wherein the size of the channel or chamber is in the range of about 0.2 to 5 mm in length, width, and / or depth.

[0051] These and other features and characteristics of the subject matter of this disclosure, as well as the methods and functions of the operation of the relevant elements of the structure, and the economics of the combination and manufacture of the components, will become more apparent by considering the following description and appended claims with reference to the accompanying drawings, all of which form part of this specification, and similar reference numbers represent corresponding components in various drawings. However, it should be clearly understood that the drawings are for illustrative and explanatory purposes only and are not intended to define limitations of the subject matter of this disclosure. Where used herein and in the claims, the singular forms "a," "an," and "the" refer to plural subjects unless the context makes it clearer otherwise.

[0052] Additional advantages and details of the subject matter of this disclosure are described in more detail below with reference to exemplary embodiments or aspects shown in the accompanying figures. [Brief explanation of the drawing]

[0053] [Figure 1A-1C] This diagram shows a conventional process for manufacturing parts with their final shape, bonded by reaction. Figure 1A shows an untreated preform, Figure 1B shows a green processed product that is close to the final shape, and Figure 1C shows a part bonded by reaction.

[0054] [Figure 2] This is a schematic diagram of a digital photoprocessing (DLP) printer configured according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0055] [Figure 3A-3B] This figure shows a solid component fabricated via DLP according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0056] [Figure 4] This figure shows viscosity profiles for certain slurry compositions without dispersants, according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0057] [Figure 5] This figure shows viscosity profiles for certain slurry compositions with dispersants, according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0058] [Figure 6A-6C] This figure shows a component having a channel fabricated via DLP, according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0059] [Figures 7A-7B] Schematic diagrams of preforms (Figure 7A) and reaction-bonded materials (Figure 7B) are shown in some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0060] [Figure 8A-8B] Schematic diagrams of preforms (Figure 8A) and reaction-bonded materials (Figure 8B) are shown in some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0061] [Figure 9] This figure shows a cross-sectional micrograph of a reaction-bonded DLP SiC preform manufactured according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0062] [Figure 10] This is a perspective view of a ceramic body formed as a microcooler temperature control device according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0063] [Figure 11A-11C] These are various figures of a ceramic body formed as a microcooler temperature control device, according to some non-limiting embodiments or aspects of the subject matter of this disclosure.

[0064] [Figures 12A-12B] This is a top view of a ceramic body formed as a microcooler temperature control device, as a preform (Figure 12A) and as a reaction-bound compound (Figure 12B), according to some non-limiting embodiments or aspects of the subject matter of this disclosure. [Modes for carrying out the invention]

[0065] For the purposes described below, the terms “end,” “top,” “bottom,” “right,” “left,” “vertical,” “horizontal,” “top,” “bottom,” “lateral,” “longitudinal,” and their derivatives refer to the subject matter of this disclosure as oriented in the drawings. However, it should be understood that the subject matter of this disclosure may be subject to various alternative modifications and process sequences unless it is clearly indicated otherwise. It should also be understood that the specific apparatus and processes illustrated in the accompanying drawings and described in the following specification are also merely illustrative embodiments or aspects of the subject matter of this disclosure. Accordingly, specific dimensions and other physical features relating to the embodiments or aspects disclosed herein should not be considered restrictive unless otherwise indicated.

[0066] Any aspects, parts, elements, structures, actions, processes, functions, instructions, and / or similar descriptions used herein should not be construed as material or essential unless expressly stated otherwise. Furthermore, as used herein, the articles “a” and “an” are intended to include one or more items and may be used interchangeably with “one or more” and “at least one.” Additionally, as used herein, the term “set” is intended to include one or more items (e.g., related items, unrelated items, combinations of related and unrelated items, and / or similar) and may be used interchangeably with “one or more” or “at least one.” If only one item is intended, the term “one” or similar phrase is used. Furthermore, as used herein, the terms “has,” “have,” “having,” or similar are intended to be non-restrictive terms. Additionally, as used herein, the phrase “based on” is intended to mean “based at least partially” unless otherwise specified.

[0067] Looking first at Figure 1, a conventional set of processes for forming reaction-bonded components is provided. Figure 1A shows untreated SiC and carbon preforms. These untreated SiC and carbon preforms can be formed by conventional methods known in the art. Once the untreated preforms are formed, they can be green-processed to produce a near-final shape, as shown in Figure 1B. This green-processing may also be carried out by conventional methods known in the art. Once a near-final shape is formed, it can be bonded by reaction using known methods such as Si penetration, as shown in Figure 1C.

[0068] There are many problems associated with the process shown in Figure 1. For example, it is quite expensive in terms of labor and equipment. Each step contributes to a long cycle time. Green processing results in high raw material waste. In addition, it is difficult to create internal channels and cavities in the manufactured parts.

[0069] Therefore, there is a need for new methods for fabricating ceramic components in which the internal chamber can be reliably constructed. One such method involves digital light processing (DLP) three-dimensional (3D) printing.

[0070] Turning to Figure 2, a schematic example of a DLP printer is provided. In DLP, patterned light is used to cure the material layer in a single step within the resin chamber. In Figure 2, the DLP system 200 includes a high-resolution or digital light projector 210 containing a light source 215, a lens 220, a resin chamber 230 filled with liquid photopolymer, a mirror 240, and a build platform 250. As shown, the mirror 240 is a digital micromirror device (DMD) 245.

[0071] Only photopolymers that are irradiated and in physical contact with a solid surface (e.g., the build platform 250 or the previous layer) are cured. After each layer, the DLP printer performs a peeling action across the bottom 237 of the resin tank 230 to remove the cured resin at the bottom 237 of the tank. Once one layer is complete, the build platform 250 rises by the thickness of that layer (e.g., upward along the z-axis), and this process is repeated until the component 260 is complete.

[0072] DLP (Deep Layer Plating) processes are fast, low-cost, offer high durability, and can fabricate components with internal cavities and channels. DLP is commonly used for fabricating plastic components using UV-curing resins, as well as polymer / ceramic composites using UV-transparent ceramic particles such as porcelain, quartz, and aluminum oxide. However, DLP is not well-suited for fabricating polymer / UV-opaque ceramic composites if the ceramic particles are dark or opaque, not allowing sufficient light penetration to cure the polymer resin.

[0073] Looking at Figure 3A, a typical polymer / SiC composite part fabricated from resin is shown. The slurry for the part in Figure 3A contains SiC ceramic particles mixed with a photocurable polymer resin. SiC is an "opaque" ceramic with low UV light transmittance. In contrast, Figure 3B shows a polymer / SiC composite part fabricated with an additive that allows light to penetrate the resin. The slurry for the part in Figure 3B contains SiC ceramic particles and a dispersant mixed with a photocurable polymer resin. From the comparison of Figure 3A and Figure 3B, it should be understood that the composite part fabricated in Figure 3A is poorly printed and collapses, while the composite part fabricated in Figure 3B is well printed and robust.

[0074] Non-limiting embodiments or aspects of the subject matter of this disclosure relate to a photocurable ceramic slurry comprising 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant, wherein the dispersant facilitates light penetration and curing of the photocurable slurry. In some non-limiting embodiments or aspects, the photocurable slurry comprises 55% or more by weight of opaque ceramic particles, with an increasing percentage of ceramic particles preferred as an indicator of good particle filling. As used herein, opaque means particles having low UV transmittance.

[0075] In some non-limiting embodiments or aspects, the opaque ceramic particles may be selected from the group including silicon carbide, boron carbide, silicon nitride, titanium diboride, and combinations thereof. In some non-limiting embodiments or aspects, the opaque ceramic particles may have an average particle size of 5 to 30 μm. Such a ceramic particle size may promote reactive bonding in post-treatment steps.

[0076] In some non-limiting embodiments or aspects, the slurry may contain additional components. For example, the slurry may contain elemental silicon and / or boron. The slurry may also contain a photoinitiator, such as those commonly used in DLP printing, in a suitable amount, such as 0 to 5% by weight of photoinitiator.

[0077] The ceramic slurries prepared based on this disclosure generally contain a dispersant or dispersing agent. Although the dispersant is described as being 1% by weight or less in the slurry, there may be slurry compositions in which a larger amount of dispersant, such as up to 2% by weight or more, is beneficial.

[0078] Suitable dispersants include commercially available dispersants such as Tamol 963® from Dow Chemical. In some non-limiting embodiments or aspects, the dispersant causes the slurry to have a light transmission depth of 25 μm or more. In some non-limiting embodiments or aspects, the dispersant causes the slurry to have a light transmission depth of 50 μm or more. For example, the dispersant can separate particles at a fine level, creating spaces for light to penetrate. Having a greater light transmission depth that extends to two or more layers in DLP print depth can be advantageous in ensuring that light penetrates sufficiently through the slurry and that the resulting part is sufficiently cured.

[0079] In some non-limiting embodiments or aspects, the photocurable resin may be any ultraviolet digital photocurable resin suitable for use in DLP printers. Suitable photocurable resins include commercially available resins such as Anycubic standard UV resins. These photocurable resins are illustrative only, and it should be understood that any suitable photocurable resin may be used.

[0080] Turning to Figure 4 first, the viscosity profiles of 12 μm SiC powder blended with UV resin slip are shown. The UV resin used is the standard Anycubic UV polymer resin for DLP 3D printing. The viscosity profiles include numerous related profiles, including the profile for UV resin alone, as well as the profiles for UV resin with SiC, with 60, 67, and 70 wt% SiC.

[0081] In Figure 4, viscosity is shown along the y-axis and expressed in centipoise (cps). Velocity is shown along the x-axis and expressed in revolutions per minute (rpm). Liquids with low centipoise flow easily and move quickly. Higher centipoise scores indicate slower flow. In Figure 4, the viscosity scale is shown in increments of 10,000 cps, ranging from 0 to 60,000 cps. The velocity scale is shown in increments of 20 rpm, ranging from 0 to 100 rpm.

[0082] As seen in Figure 4, the profile with only UV resin is expected to have the lowest viscosity, making it easy and fast to flow and move. It is not surprising that the profile with the smallest amount of SiC and resin, which has the least amount of UV resin, is the most viscous and appears to be able to flow only up to 20 rpm. What is interesting is how small changes in the amount of resin result in such a large decrease in viscosity for the 67 wt% SiC and 60 wt% SiC profiles, allowing these resin slips to behave similarly to the UV resin-only profile.

[0083] Now, looking at Figure 5, the viscosity profiles of 12 μm SiC powder blended with UV resin slip are shown. The UV resin used is standard Anycubic UV polymer resin for DLP 3D printing. The viscosity profiles include numerous related profiles, including the profile for 60 wt% SiC and UV resin, the profile for 60 wt% SiC and UV resin with 1 wt% dispersant, the profile for 60 wt% SiC and UV resin with 2 wt% dispersant, and the profile for 60 wt% SiC and UV resin with 3 wt% dispersant. The dispersant used is the commercially available dispersant Tamol 963®.

[0084] In Figure 5, the viscosity scale is shown in 1,000 cps increments, ranging from 0 to 8,000 cps. The velocity scale is shown in 20 rpm increments, ranging from 0 to 100 rpm. A comparison of Figures 4 and 5 clearly shows that the profiles of 60 wt% SiC and UV resin are the same 60 wt% SiC and UV resin profiles, shown on different scales. This illustrates the effect of adding a dispersant to the profile in Figure 5.

[0085] The profiles of 60 wt% SiC and UV resin with 1 wt% dispersant, 2 wt% dispersant, and 3 wt% dispersant are found to have nearly identical performance. Note that adding even a small amount of dispersant reduces the viscosity of the prepared slip by approximately 500 cps at 100 rpm compared to the 60 wt% SiC and UV resin profile. Lower viscosity in the prepared slip or slurry is preferred to allow for a higher content of added ceramic particles (e.g., SiC).

[0086] Generally, slurries with a higher ceramic content allow for DLP printing of preforms with a higher ceramic content. Preforms with a higher ceramic content are better for ceramic processing, for example, by reducing part shrinkage after penetration and improving dimensional accuracy.

[0087] In some non-limiting embodiments or aspects, the slurry may have a viscosity of 1,000 to 30,000 cps at temperatures in the range of 20 to 50°C. These temperatures may be measured in the resin bath and may be referred to as the "bath temperature" for the printer.

[0088] Returning to Figures 3A and 3B, the parts were fabricated via DLP using slips (Figure 3A) with 60 wt% 12 μm SiC powder blended with Anycubic Basic UV resin and 1 wt% Tamol 963®. While we do not wish to be bound by any particular theory, DLP printing of SiC powder and UV resin slurries is considered difficult because SiC is a "UV dark particle," meaning that UV light cannot penetrate the slurry sufficiently and cannot cure it deeply. This is illustrated by the poorly printed part in Figure 3A.

[0089] In contrast, in Figure 3B, the print quality is significantly improved by adding a dispersant. This is thought to be due to the fine-scale particle separation provided by the dispersant, which allows light to penetrate deeply into the resin. Therefore, UV light was able to penetrate the slurry containing the dispersed particles, making it possible to fabricate the part shown in Figure 3B.

[0090] Referring to Figures 6A-6C, an example of a pinned wafer chuck component fabricated via DLP using a SiC slurry with a dispersant is shown. As provided above, DLP is suitable for fabricating components with small channel shapes. Because DLP is a liquid-based process, it allows for the removal of channels after the printing process, which is difficult to achieve with other 3D printing methods such as powder-bed 3D printing.

[0091] Figure 6A shows a polymer preform component close to the final shape printed from DLP. Figure 6B shows the preform component from Figure 6A after sample evacuation. Figure 6C shows the evacuated preform component with a clearly visible channel.

[0092] Non-limiting embodiments or aspects of the subject matter of this disclosure relate to a method for producing a ceramic component from a photocurable slurry, the method comprising: placing a photocurable slurry into a photocurable resin tank; irradiating the slurry with light to react a portion of the slurry to form a preform ceramic component; and bonding the preform ceramic components by reaction to obtain a ceramic component. The photocurable slurry may comprise: 50-70% by weight of opaque ceramic particles; 30-50% by weight of a photocurable resin; and 0.3-1% by weight of a dispersant.

[0093] In some non-limiting embodiments or aspects, the method may be carried out using a DLP 3D printer. As used herein, the terms digital photoprocessing 3D printer, DLP printer, and DLP 3D printer may be used interchangeably to refer to the same type of printer. It should be understood that the schematic assembly provided in Figure 2 includes numerous parts, but is not exhaustive. For example, any suitable DLP 3D printer may be used to fabricate ceramic parts from the slurry disclosed herein.

[0094] In some non-limiting embodiments or aspects, the light source is preferably a UV light source, such as those typically found in DLP printers. In some non-limiting embodiments or aspects, the UV light has a wavelength of about 300 to 450 nm and a power of about 1 to 50 mW / cm². 2 It is provided at a light intensity.

[0095] In some non-limiting embodiments or aspects, irradiating the slurry with light may include using an ultraviolet (UV) light source to provide UV light to a portion of the slurry in a photocuring resin tank, the UV light being provided at a wavelength of approximately 300–450 nm. The light intensity may vary, but is generally about 1–50 mW / cm². 2 That is the case.

[0096] In some non-limiting embodiments or aspects, the DLP printer includes a projector configured to project a two-dimensional image of each layer of the preformed ceramic component. When projected onto the bottom surface of the resin tank, each layer of the preformed ceramic component is cured using a UV light source. The aggregate of layers forms a preformed ceramic component as shown in Figure 6.

[0097] In some non-limiting embodiments or aspects, one or more layers of the preform ceramic component may include a surface shape with channels or grooves, as shown in Figures 3B and 6C. The size of the channels or grooves may range from about 0.2 to 5 mm in length, width, and / or depth. In some non-limiting embodiments or aspects, the size of the channels or grooves may range from about 0.6 to 2 mm in length, width, and / or depth.

[0098] As shown in Figure 6B, after the preform ceramic component is formed, the unreacted slurry can be discharged from the preform ceramic component.

[0099] After 3D DLP printing a slurry of SiC particles and resin (polymer) into a shape close to the final form, as shown in Figures 6A-6C, the SiC / polymer preform is carbonized or thermally decomposed to convert the polymer into carbon (e.g., thermal decomposition). For example, the carbonization or thermal decomposition process may be carried out using N2 at 600°C or using other preferred parameters to thermally decompose the polymer in the preform and convert it into carbon. The resulting SiC and carbon preform is preferred for a reaction-bonding (Si infiltration) process.

[0100] Once the SiC preform is formed, it can be bonded by reaction, as shown in the conventionally fabricated preform component in Figure 1. For example, although not shown, with respect to the preform component in Figure 6C, subsequent reaction bonding can yield a sufficiently dense SiSiC ceramic component with internal channels.

[0101] Referring here to Figures 7 and 8, schematic diagrams of preforms (Figures 7A and 8A) and reaction-bonded materials (Figures 7B and 8B) are shown in some non-limiting embodiments or aspects of the subject matter of this disclosure. Figure 7 shows the reaction-bonding process of SiC, and Figure 8 shows the reaction-bonding process of boron carbide (B4C).

[0102] Figure 7A shows the preform material 708. The preform material 708 may include ceramic particles 732 and carbon particles 736. As shown, the ceramic particles 732 are silicon carbide 742. In some non-limiting embodiments or aspects, the ceramic particles may include silicon nitride and titanium diboride.

[0103] The preform material 708 may further contain residual elemental silicon and / or boron. In some non-limiting embodiments or aspects, the preform material 708 includes voids 720.

[0104] Figure 7B shows a ceramic material 710 bonded by reaction. Material 710 can be formed by applying an infiltration process of silicon (or an alloy of silicon with aluminum, boron, titanium, and / or similar). In the non-limiting example shown in Figure 7B, molten silicon 738 may infiltrate the preform material 708 from Figure 7A to form material 710 in Figure 7B. The molten silicon 738 may react with carbon particles 736 to form reaction-formed SiC particles 740, in addition to unreacted SiC particles 744. Material 710 may further contain residual elemental silicon and / or silicon alloys. In some non-limiting embodiments or aspects, material 710 contains residual Si 750.

[0105] Similarly, Figure 8A shows the preform material 808. The preform material 808 may contain boron carbide ceramic particles or boron carbide and silicon carbide particles 832 and carbon particles 836. The preform material 808 may further contain residual elemental silicon and / or boron. In some non-limiting embodiments or aspects, the preform material 808 includes voids 820.

[0106] Figure 8B shows a ceramic material 810 bonded by reaction. Material 810 can be formed by applying an infiltration process of silicon (or an alloy of silicon with aluminum, boron, titanium, and / or similar). In the non-limiting example shown in Figure 8B, molten silicon 838 may infiltrate the preform material 808 from Figure 8A to form material 810 in Figure 8B. The molten silicon 838 may react with carbon particles 836 to form reaction-formed SiC particles 840, in addition to unreacted boron carbide and / or silicon carbide particles. Material 810 may further contain residual elemental silicon and / or silicon alloys. In some non-limiting embodiments or aspects, material 810 contains residual Si 850.

[0107] The formed materials 710 and 810 may exhibit beneficial properties such as low thermal expansion, high thermal conductivity, high hardness, high wear resistance, high rigidity, high temperature capacity, and / or a low coefficient of friction.

[0108] In some non-limiting embodiments, Al may be incorporated into the Si infiltration. Reinforcement from SiC bonded by the Al-modified reaction includes a CTE adapted to the purpose, higher thermal conductivity, and higher fracture toughness.

[0109] Referring here to Figure 9, a cross-sectional micrograph of a reaction-bonded DLP SiC preform manufactured according to some non-limiting embodiments or aspects of the subject matter of this disclosure is shown. This reaction-bonded preform was fabricated via 3D DLP using a SiC slurry with a dispersant. Microstructure evaluation at 700x magnification in Figure 9 shows that the impregnated preform has a SiC content of approximately 60 vol% and that 12 μm SiC particles are uniformly distributed in the matrix and surrounded by residual Si.

[0110] Of particular interest are the ceramic components fabricated by the slurries and processes disclosed herein. For example, a vacuum wafer chuck, as shown in Figure 6, may be fabricated using the photocurable ceramic slurry of the present disclosure. Such a wafer chuck may include a body and separation pins for supporting a semiconductor wafer, the pins being at least partially located within the body.

[0111] Additionally, thermal management or micro-channel cooling devices, such as heat sink devices, can be fabricated. Such micro-channel cooling devices may be used for high-power microelectronic cooling applications (e.g., server farms, AI devices, etc.). In some non-limiting embodiments, the thermal management device comprises a ceramic body fabricated using a photocurable ceramic slurry of the present disclosure, having a network structure of channels defined on the surface of the ceramic body.

[0112] An example of a micro-channel cooling device 1000 is shown in Figure 10. The micro-channel cooling device includes a ceramic body 1010, which may be modified to form a heat sink 1040 by defining a channel 1060 on the surface of the ceramic body 1010 and / or by attaching an extension (not shown) to the ceramic body 1010. The ceramic body 1010 is shown to have a square top surface, but it will be understood that any preferred shape of the ceramic body 1010 may be used. Non-limiting examples of ceramic materials on which the ceramic body 1010 may be formed include silicon carbide (SiC), boron carbide (B4C), or any combination thereof.

[0113] As shown in Figure 10, the mesh structure of the channel 1060 may be defined on the surface of the ceramic body 1010. The arrangement and dimensions of the mesh structure of the channel 1060 are not limiting, and it will be understood that other arrangements and dimensions of the channel 1060 may be used in connection with this disclosure. The arrangement of the channel 1060 may refer to the direction in which a number of channels 1060 and / or channels 1060 are defined and / or the shape of the channels 1060 and / or the general selection of the location of the channels 1060 in the ceramic body 1010. The dimensions of the channel 1060 may refer to the length and / or width and / or depth of the channels 1060. The arrangement and dimensions of the channel 1060 in the ceramic body 1010 may be selected to optimize thermal management capabilities.

[0114] For example, the dimensions of the channel or groove may range from approximately 0.2 to 5 mm in length, width, and / or depth. Additionally, it is understood that although the channel or groove is shown on the surface of the ceramic body 1010, it may also be located inside the ceramic body 1010. This can be achieved during the DLP printing process, where individual layers may contain voids or gaps in material (resin) where the channel or groove is desired. Examples showing internal grooves and / or channels are provided in Figures 11-12.

[0115] Based on the principles of this disclosure, the arrangement of the ceramic body 1010 and channel 1060 is fabricated via DLP printing using a ceramic slurry containing a dispersant. The fabricated polymer preform is then ejected as shown in Figure 6B and may subsequently be carbonized. As shown in Figures 7-8, the carbonized preform material can be bonded reactively (e.g., by a reactive penetration process of silicon or boron) to form a reactively bonded ceramic component. In some non-limiting embodiments, the reactively bonded ceramic component comprises silicon carbide and / or boron carbide bodies.

[0116] Now, looking at Figure 11, an example of a micro-channel cooling device 1100 is shown. Figure 11A shows a top perspective view of the device 1100, Figure 11B shows a front cross-sectional perspective view of the device 1100, showing multiple internal channels 1160, and Figure 11C shows a top cross-sectional view of the device 1100, showing multiple chambers formed from the channels 1160.

[0117] The micro-channel cooling device includes a ceramic body 1110, which may be modified to form a heat sink 1140 by defining a channel 1160 on the inner surface of the ceramic body 1110. Although the ceramic body 1110 is shown to have a square top surface, it will be understood that any preferred shape of the ceramic body 1110 may be used. Non-limiting examples of ceramic materials on which the ceramic body 1110 may be formed include silicon carbide (SiC), boron carbide (B4C), or any combination thereof.

[0118] As shown in Figure 11, the mesh structure of the internal channels 1160 may be defined on the inner surface of the ceramic body 1110. The arrangement and dimensions of the mesh structure of the channels 1160 are not limiting, and it will be understood that other arrangements and dimensions of the channels 1160 may be used in connection with this disclosure. The arrangement of the channels 1160 may refer to a general selection of the orientation in which a number of channels 1160 and / or channels 1160 are defined and / or the shape of the channels 1160 and / or the location of the channels 1160 in the ceramic body 1110. The dimensions of the channels 1160 may refer to the length and / or width and / or depth of the channels 1160. The arrangement and dimensions of the channels 1160 in the ceramic body 1110 may be selected to optimize thermal management capabilities.

[0119] For example, the dimensions of the channel or groove may be in the range of approximately 0.2 to 5 mm in length, width, and / or depth. Additionally, it is understood that the channel or groove may be shown on the surface of the ceramic body 1110, but may also be located inside the ceramic body 1110. This can be achieved during the DLP printing process, where individual layers may contain voids or gaps in material (resin) where the channel or groove is desired.

[0120] Now, looking at Figures 12A and 12B, we see top views of the ceramic body formed as a microcooler temperature control device, both as a preform (Figure 12A) and as a composite formed by reaction (Figure 12B).

[0121] In Figure 12A, the micro-channel cooler 1200a may be a heatsink 1240a having a mesh structure of internal channels 1260a defined on the inner surface of the ceramic body 1210a. It can be understood that Figure 12A corresponds to a SiC preform with the inlet and outlet ports removed, based on the example shown in Figure 11.

[0122] Similarly, in Figure 12B, the micro-channel cooling device 1200b may be a heat sink 1240b having a mesh structure of internal channels 1260b defined on the inner surface of the ceramic body 1210b. In Figure 12, the micro-channel cooling device 1200b is identical to the micro-cooling device 1200a, except that the device 1200b is subjected to a carbonization or thermal decomposition process (e.g., Si infiltration) to produce a ceramic component bonded by reaction.

[0123] It should be noted that apparatus 1200a is slightly larger than apparatus 1200b (width of 1200b is 29.3 mm compared to width of 1200a is 32.1 mm). This corresponds to a shrinkage of approximately 9%, which can be expected from reaction bonding or the Si infiltration process. In some non-limiting embodiments or aspects, the total shrinkage from this process is preferably less than about 15%, more preferably less than about 10%, and most preferably less than about 5%.

[0124] The subject matter of this disclosure has been described in detail for illustrative purposes based on what is currently considered to be the most practical and preferred embodiment or aspect; however, such details are for illustrative purposes only and should be understood as not limiting the subject matter of this disclosure to the embodiments or aspects of this disclosure, but rather intended to encompass modifications and equivalent procedures that are in the spirit and scope of the appended claims. For example, it should be understood that, to the extent possible, the subject matter of this disclosure is intended to allow one or more features of any embodiment or aspect to be combined with one or more features of any other embodiment or aspect. [Explanation of Symbols]

[0125] 200 DLP system 210 Projector 215 Light source 220 Lens 230 Resin tank 235 (No matching words found) 237 Bottom 240 Mirror 245 Digital Micromirror Device (DMD) 250 build platforms 260 components 708 Preform Materials 710 Ceramic materials bonded by reaction 720 void 732 Ceramic particles 736 carbon particles 738 Molten silicon 740 SiC particles formed by the reaction 742 Silicon Carbide 744 Unreacted SiC particles 750 Residual Si 808 Preform Materials 810 Ceramic materials bonded by reaction 820 void 832 Boron carbide ceramic particles or boron carbide and silicon carbide particles 834 (No matching words found) 836 carbon particles 838 Molten silicon 840 SiC particles formed by the reaction 850 residual Si 1000 Micro-Channel Cooling System 1010 Ceramic body 1040 Heatsink 1060 channels 1100 Micro-Channel Cooling System 1110 Ceramic body 1140 Heatsink 1160 internal channels 1200A Micro-Channel Cooling System 1210A Ceramic body 1240A Heatsink 1260A Internal Channel 1200B Micro-Channel Cooling System 1210B Ceramic Body 1240B Heatsink 1260B internal channel

Claims

1. 50-70% by weight of opaque ceramic particles; 30-50% by weight of photocurable resin; and 0.3 to 1% by weight of dispersant A photocurable ceramic slurry comprising; the dispersant facilitates light penetration and curing of the photocurable slurry.

2. The slurry according to claim 1, further comprising 0 to 5% by weight of a photoinitiator.

3. The slurry according to claim 1, wherein the opaque ceramic particles are selected from the group consisting of silicon carbide, boron carbide, silicon nitride, and titanium diboride.

4. The slurry according to claim 3, wherein the opaque ceramic particles have an average particle size of 5 to 30 μm.

5. The slurry according to claim 3, further comprising elemental silicon.

6. The slurry according to claim 1, wherein the photocurable resin includes an ultraviolet digital light-treated resin.

7. The slurry according to claim 1, having a viscosity of 1,000 to 30,000 cps at a temperature in the range of 20 to 50°C.

8. The slurry according to claim 1, wherein the dispersant provides a light transmission depth of 25 μm or more.

9. A method for fabricating ceramic parts from a photocurable slurry: 50-70% by weight of opaque ceramic particles; 30-50% by weight of photocurable resin; and 0.3 to 1% by weight of dispersant The process involves placing a photocurable slurry containing the following into a photocurable resin tank, The slurry is irradiated with light to cause a portion of the slurry to react and form a preformed ceramic component; The aforementioned preform ceramic components are bonded together by reaction to obtain a ceramic component. Methods that include...

10. The method according to claim 9, which is carried out using a digital optical processing 3D printer.

11. Irradiating the slurry with light: The method according to claim 9, comprising using an ultraviolet (UV) light source to provide UV light to a portion of a slurry in a photocuring resin tank, wherein the UV light is provided at a wavelength of approximately 300 to 450 nm.

12. Projecting a two-dimensional image of each layer of the aforementioned preform ceramic component; Using an ultraviolet light source, each layer of the preform ceramic component is cured to form the preform ceramic component. The method according to claim 9, further comprising:

13. The method according to claim 12, wherein one or more layers of the preform ceramic component include a surface shape that includes channels or grooves.

14. The method according to claim 13, wherein the size of the channel or groove is in the range of about 0.2 to 5 mm in length, width, and / or depth.

15. The method according to claim 9, further comprising removing any unreacted slurry from the preform ceramic component.

16. The method according to claim 9, further comprising thermally decomposing the preform ceramic component to thermally decompose any residual resin into carbon.

17. The method according to claim 9, wherein the bonding by reaction includes Si penetration.

18. The method according to claim 9, wherein the ceramic component bonded by the reaction comprises silicon carbide, boron carbide, pure carbon, silicon nitride, and / or titanium diboride.

19. The main body and A separation pin for supporting a semiconductor wafer, and at least partially located within the main body, and A vacuum wafer chuck comprising the following: 50-70% by weight of opaque ceramic particles; 30-50% by weight of photocurable resin; and 0.3 to 1% by weight of dispersant A vacuum wafer chuck formed from a photocurable ceramic slurry containing [a specific substance].

20. Ceramic body and; The ceramic body has a network structure of channels defined on its surface and A thermal control device comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of photocurable resin; and 0.3 to 1% by weight of dispersant A thermal control device formed from a photocurable ceramic slurry containing [a specific substance].

21. The thermal control apparatus according to claim 20, wherein the ceramic body comprises silicon carbide and / or boron carbide.

22. Ceramic body and; The network structure of the internal channels and / or chambers in the ceramic body A thermal control device comprising: 50-70% by weight of opaque ceramic particles; 30-50% by weight of photocurable resin; and 0.3 to 1% by weight of dispersant A thermal control device formed from a photocurable ceramic slurry containing [a specific substance].

23. The thermal management device according to claim 22, wherein the ceramic body contains silicon carbide and is formed by digital photoprocessing 3D printing.

24. The thermal control apparatus according to claim 22, wherein the size of the channel or chamber is in the range of about 0.2 to 5 mm in length, width, and / or depth.

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