Conductive guide hole and manufacturing method thereof

Abstract

The invention provides a conductive via and a manufacturing method thereof. The electrical component is provided by a plated-through hole extending through the glass substrate. The electrical component may be manufactured by forcing a suspension of conductive particles suspended in a liquid medium through the aperture. The suspension may be forced into the bore under pressure differences, centrifugal forces, or electrostatic forces, etc. The liquid medium in the pores may be dried, and the particles may be sintered. The particles may be further encapsulated in the pores. Alternatively or additionally, the particles may be pressed against the outer surface of the substrate to create a raised structure.

Description

[0001] This application is a divisional application of the application patent application with the application date of September 30, 2020, application number 202080082585.X (international application number PCT / US2020 / 053363), and the invention name of “Conductive vias and methods of making the same”. Cross Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application Serial No. 62 / 908,496, filed September 30, 2019, U.S. Patent Application Serial No. 62 / 923,737, filed October 21, 2019, and U.S. Patent Application Serial No. 63 / 038,496, filed June 12, 2020, the disclosures of which are incorporated by reference herein in their entireties. BACKGROUND

[0003] 2.5-D and 3-D packaging are new implementations of an established concept previously known as multichip modules (MCMs). Thin glass, silicon or other dielectric substrate material is formed with multiple holes or vias that are metallized to form electrical paths. The integrated circuit packaging industry refers to these interconnect substrates as interposers. The holes made in the interposers are typically very small, e.g., 5 microns to 100 microns in diameter and 50 microns to 500 microns in depth. The number of holes per square centimeter can be in the hundreds or even thousands. After the processes required to make these holes, the next step is to metalize the holes to provide conductive pathways from one circuit plane or substrate to another.

[0004] Methods in the prior art that are “copper electroplating” methods for metallizing interposers and blind vias are very expensive and typically lack manufacturing scalability. The metallization methods include a combination of physical vapor deposition (PVD) or evaporation or sputter deposition to form an adhesion / barrier / or seed layer followed by electroplating, typically copper plating. The equipment required to operate these processes is expensive and difficult to manufacture in large scale. For example, depending on the substrate size, hole diameter and aspect ratio, the copper electroplating process can typically take 1 to 8 hours for each substrate. The electroplating process requires electroplating in a single processing unit with complex analytical and dispensing control and precise chemical element and electrical field distribution across the substrate for each substrate.

[0005] Electroplated copper deposits that extend beyond the surface of a substrate are referred to in the art as "overplating." In order to planarize or level copper electroplated deposits with the surface of a substrate, chemical mechanical polishing (CMP) is typically required. The maintenance and operation of the CMP process requires highly skilled technicians to monitor and control in order to achieve consistent results. Copper is a relatively soft metal and methods to mechanically remove excess copper are limited to loading the softer copper into abrasives.

[0006] A second method of depositing copper or other conductive material into a via in an interposer substrate utilizes a metal ink. Metal inks are typically formulated using metal powders dispersed in a binding resin or other polymer to facilitate hole filling and a capping agent to prevent oxidation of the metal powders. After filling the hole with the metal ink along with the resin or capping agent, it is necessary to volatilize and remove all of the organic materials from the metal powders to achieve the required electrical conductivity. The temperatures required to volatilize these organic compounds can reach 400 °C to 800 °C. The carbon ash left behind after volatilizing the organic compounds can negatively impact the optimized electrical conductivity and leave serious discontinuities in the filling of the hole, and the potential for discontinuities or open electrical areas in the hole or via is unacceptable.

[0007] Most of these processes are only applicable to very limited hole length / width, and narrow or ultra-wide holes are difficult to manufacture in a consistent manner. SUMMARY

[0008] According to one example of the present disclosure, an electrical component can include a substrate defining a first surface and a second surface opposite the first surface, and a conductive via extending from the first surface to the second surface such that the first and second surfaces define respective first and second openings of the via. The electrical component can also include a conductive fill extending in the via from the first surface to the second surface, wherein the conductive fill defines a conductive path from the first surface to the second surface. BRIEF DESCRIPTION OF DRAWINGS

[0009] The foregoing summary, as well as the following detailed description of illustrative embodiments of the present application, will be better understood when read in conjunction with the accompanying drawings, in which:

[0010] FIG. 1A is a perspective view of a substrate having a plurality of hole arrays each defining a respective plurality of holes;

[0011] FIG. IB is a schematic cross-sectional side view of a portion of the substrate shown in FIG. 1A, showing a via and a blind hole;

[0012] Figure 2A is a schematic cross-sectional side view similar to Figure 1, but showing the holes filled with electrically conductive fill to define electrically conductive vias, and an electrically conductive redistribution layer over the vias;

[0013] Figure 2B is an SEM micrograph of one of the vias shown in Figure 2A;

[0014] Figure 3 is a flowchart showing method steps of a method for electrically conductively filling the holes shown in Figure IB to make the electrically conductive vias shown in Figure 2A;

[0015] Figure 4A is a perspective view of a suspension of electrically conductive particles in a liquid medium;

[0016] Figure 4B is a perspective view of the suspension after agitation;

[0017] Figure 4C is a perspective view of a second suspension;

[0018] Figure 5 is a schematic cross-sectional view of a vacuum filling apparatus arranged to drive the suspension into the holes of a substrate;

[0019] Figure 6A is a schematic side view of a portion of the substrate shown in Figure IB, showing a first electrically conductive fill made in one of the holes after a first filling operation using the vacuum filling apparatus shown in Figure 5;

[0020] Figure 6B is a schematic side view of the portion of the substrate shown in Figure 6A after a compaction operation has increased the packing density of the first electrically conductive fill;

[0021] Figure 7A is a schematic view of the particles of the suspension shown in Figures 4A-4B, showing a substantially monosized distribution of electrically conductive particles;

[0022] Figure 7B is a schematic cross-sectional view of the particles of the suspension shown in Figures 4A-4B, showing a bimodal distribution of small and large particles, according to an alternative embodiment;

[0023] Figure 7C is a schematic cross-sectional view of the particles of the suspension shown in Figures 4A-4B, showing a trimodal distribution of small, large, and medium-sized particles;

[0024] Figure 8A is a schematic cross-sectional view of a substrate arranged in an envelope arranged to compress the particles and remove the liquid medium after a filling operation;

[0025] Figure 8B is a schematic cross-sectional view of the substrate arranged in the envelope shown in Figure 8A, showing the envelope in contact with the surface of the substrate;

[0026] Figure 8C is a schematic cross-sectional view of the substrate disposed in the envelope as shown in Figure 8B, but showing the envelope under pressure during an extrusion operation to densely pack the particles in the wells of the substrate;

[0027] Figure 9A is a schematic side view of a portion of the substrate shown in Figure 6A, showing after a subsequent fill operation using the vacuum fill apparatus shown in Figure 5;

[0028] FIG. 9B Figure 9B is a schematic side view of the portion of the substrate shown in Figure 9A, showing after extrusion of the subsequent fill, and addition of a third fill operation using the vacuum fill apparatus shown in Figure 5;

[0029] Figure 9C is a schematic side view of the portion of the substrate shown in Figure 9A, showing after the second and third fill operations;

[0030] Figure 10 is a schematic cross-sectional view of a hanging vacuum fill apparatus similar to Figure 5, but configured to hang the substrate;

[0031] Figure 11 is a schematic cross-sectional side view of the substrate shown in Figure 9C, with the substrate filled by the vacuum fill apparatus;

[0032] Figure 12A is a schematic cross-sectional side view of the substrate shown in Figure 11, showing after a sequence of fill\dry and press operations, and showing the wells filled with a port fill suspension of small particles;

[0033] Figure 12B is an enlarged schematic cross-sectional side view of the substrate shown in Figure 12A, showing after extrusion of the small particles;

[0034] Figure 12C is an enlarged schematic cross-sectional side view of the substrate shown in Figure 12A, showing a fill well according to another example;

[0035] Figures 13A-C illustrate a method of delivering a suspension to wells of a substrate during a fill operation in one example, whereby;

[0036] Figure 13A illustrates the substrate in an initial angular orientation;

[0037] Figure 13B illustrates the substrate in a first angular orientation different from the initial angular orientation;

[0038] Figure 13C illustrates the substrate in a second angular orientation opposite the first angular orientation;

[0039] Figure 13D illustrates a method of delivering a suspension to wells of a substrate during a fill operation in another example;

[0040] FIG. 14 is a schematic cross-sectional side view of method steps for sintering a substrate;

[0041] FIG. 15A is a schematic side view of adjacent ones of the particles in the particles in the hole after pressing and before sintering;

[0042] FIG. 15B is a schematic side view of adjacent ones of the particles in the hole after sintering;

[0043] FIG. 16A is a schematic side view of the substrate shown in FIG. 14, but after sintering, showing a surface finishing operation;

[0044] FIG. 16B is a schematic side view of the substrate shown in FIG. 16A, showing hermetic sealing after the surface finishing operation;

[0045] FIG. 17 is a schematic view of the substrate of FIG. 16A, showing a conductive redistribution layer applied to the substrate, according to one example;

[0046] FIG. 18A is a schematic view of the substrate of FIG. 16A, showing a trench formed in an outer surface thereof;

[0047] FIG. 18B is a schematic view of the substrate of FIG. 18A, showing a conductive redistribution layer applied to the substrate in the trench;

[0048] FIG. 18C is a schematic view of a substrate having a conductive redistribution layer constructed according to another embodiment;

[0049] FIG. 18D is a schematic view of a substrate having a conductive redistribution layer constructed according to yet another embodiment;

[0050] FIG. 18E is a schematic view of a substrate having a conductive redistribution layer constructed according to yet another embodiment;

[0051] FIG. 19A is a schematic top plan view of a centrifuge for filling a hole according to an optional embodiment, showing a plurality of rotatable hoppers;

[0052] FIG. 19B is a schematic side view of the substrate shown in FIG. 1A, shown as being placed into one of the hoppers and covered with a suspension of conductive particles;

[0053] FIG. 19C is a schematic side view of the hopper shown in FIG. 19B, showing the hopper oriented during rotation of the centrifuge;

[0054] FIG. 19D is a schematic side view of the hopper shown in FIG. 19C, showing that the centrifugal force has forced the conductive particles into the hole of the substrate;

[0055] FIG. 19E is a schematic side view of the hopper shown in FIG. 19D, showing removal of the suspension from the outer surface of the substrate;

[0056] FIG. 20A is a schematic view of a substrate showing a weakened region after ablation;

[0057] FIG. 20B is a schematic view of the substrate shown in FIG. 20A, but showing a conductive layer applied to the inner surface of the substrate;

[0058] FIG. 20C is a schematic view of the substrate shown in FIG. 20B, but showing the weakened region removed to expose a hole, and including a mask applied to the conductive layer;

[0059] FIG. 20D is a schematic view of the substrate shown in FIG. 20C, but showing conductive particles driven into the hole;

[0060] FIG. 20E is a schematic view of the substrate shown in FIG. 20C, but showing conductive particles packed in the hole and extending along the entire length of the hole;

[0061] FIG. 20F is a schematic view of the substrate shown in FIG. 20E, but showing removal of the conductive layer in one example;

[0062] FIG. 20G is a schematic view similar to FIG. 20D, but showing application of an electrostatic force to the suspension to fill the hole of the substrate according to another example;

[0063] FIG. 21A is a schematic view of a substrate having an inner surface defining a hole containing conductive particles, the substrate including a conductive coating that bonds the conductive particles to the inner surface;

[0064] FIG. 21B is an enlarged schematic view of a portion of the substrate shown in FIG. 21A, showing a portion of the coating;

[0065] FIG. 22A is a schematic view of a hard press applied to an overfilled substrate according to another example;

[0066] FIG. 22B is a schematic view of the hard press of FIG. 22A, but including a squeezing component in another embodiment;

[0067] FIG. 22C is a schematic view of the substrate after a hard press operation;

[0068] FIG. 23A is a schematic view of a uniaxial pressing step, in which a substrate is disposed between first and second squeezing components in a vacuum envelope;

[0069] FIG. 23B is a schematic view of the uniaxial pressing step of FIG. 23A, showing a uniaxial force applied to the substrate;

[0070] FIG. 24A is a schematic illustration of an isostatic pressing step in which a substrate is disposed in a vacuum envelope and is configured to be pressed by first and second opposing structures of the envelope;

[0071] FIG. 24B is a schematic illustration of an isostatic pressing step in which a substrate is disposed in a vacuum envelope and is configured to be pressed by first and second layers disposed between opposing first and second structures of the substrate and the envelope, respectively;

[0072] FIG. 25 is a perspective view of platelets between a plurality of platelets deposited at one or both of external assist devices of a port fill;

[0073] FIG. 26 is a schematic overview of an assembly configured to be mounted to components of an interposer of the type described herein;

[0074] FIG. 27 is a schematic cross-sectional elevation view of a hybrid filled via in another example; and

[0075] FIG. 28 is a schematic cross-sectional view of a metallized via including a hole filled with a conductive material and a polymer at least partially filled with a conductive material. DETAILED DESCRIPTION

[0076] This application can describe one or more different disclosures. Moreover, for one or more of the disclosures described herein, a number of alternative embodiments can be described; it should be understood that these are presented for illustrative purposes only and do not limit the disclosures contained herein or the claims presented in any way. One or more of the present disclosures can be widely applied to many embodiments, as is apparent from the present disclosure, embodiments are described in sufficient detail to enable one of ordinary skill in the art to practice one or more of the present disclosures, and it will be appreciated that other embodiments can be utilized and structural, logical, software, electrical, and other changes can be made without departing from the scope of a particular disclosure. Accordingly, those skilled in the art will realize that one or more of the particular features of the one or more disclosures described herein can be and are susceptible to

[0077] The description of embodiments having several components joined together does not imply that all of these components are necessary. Rather, various optional components may be described to illustrate various possible embodiments of one or more of this disclosure, and to illustrate one or more aspects of this disclosure more fully. Similarly, although process steps, method steps, algorithms, etc., may be described in sequential order, such processes, methods, and algorithms may generally be configured to operate in an alternative order unless explicitly stated otherwise. In other words, any order or sequence of steps that may be described in this patent application does not itself indicate that the steps are performed in that order. The steps of the described process can be performed in any order. Furthermore, although described or implied to occur non-simultaneously (e.g., because a step is described after another step), some steps may be performed concurrently. Furthermore, some steps shown in a method may be omitted. Moreover, the process depicted with reference to the accompanying drawings does not imply that the process shown does not include other variations and modifications thereof, and does not imply that any step of the process shown or its steps is necessary for one or more of the disclosures, and does not imply that the process shown is preferred. Furthermore, each embodiment generally describes one step, but this does not mean that they must occur once, or that they may occur only once each time a process, method, or algorithm is performed. In some embodiments or cases, certain steps may be omitted, or in a given embodiment or occurrence, some steps may be performed more than once. Furthermore, in some embodiments, certain steps may be removed. Additionally, other steps may be added as needed.

[0078] For clarity, the technologies and institutions described or referenced herein will sometimes be described in the singular. However, it should be understood that, unless otherwise stated, a particular embodiment may include multiple iterations of the technology or multiple instantiations of the institution. Descriptions of processes or diagrams shown in the figures should be understood as representing modules, segments, or portions of code including one or more executable instructions for implementing a particular logical function or step in the process. Alternative implementations are included within the scope of embodiments of this disclosure, wherein, for example, functionality may be performed from the order shown or discussed, including substantially simultaneous or reverse order, depending on the functionality involved, as will be understood by those skilled in the art.

[0079] Referring first to Figures 1A-1B, substrate 20 defines opposing outer surfaces, including a first surface 22 and a second surface 24 opposite to the first surface. Substrate 20 also includes a plurality of inner surfaces 29 defining corresponding plurality of holes 26. The holes 26 extend along a central axis from the first surface 22 toward the second surface 24. For example, the holes may extend along a central axis from the first surface 22 to the second surface 24. Substrate 20 may be cut into wafers with diameters of 150 mm, 200 mm, or 300 mm; however, it should be recognized that substrate 20 may be set to any suitable diameter or other maximum size as needed. Therefore, unless otherwise stated, the term "diameter" may be used interchangeably with the term "maximum cross-sectional size" to indicate that the reference structure does not necessarily need to be circular.

[0080] Hole 26 can have any suitable diameter as needed. For example, hole 26 can have a diameter or other cross-sectional dimensions from 10 micrometers to 25 micrometers. Hole 26 can have a depth ranging from 100 micrometers to 500 micrometers along its respective central axis. There is no upper limit to the diameter requirement. For this method, the diameter-to-depth ratio between the hole diameter and the hole depth is unrestricted. In addition, multiple different hole diameters can be placed in the same substrate. Hole 26 can be conical, cylindrical, hourglass-shaped, or can be set to any suitable shape along their length. Hole 26 can be arranged in one or more hole arrays 27 as needed. Thus, substrate 20 can define one or more arrays 27, which are spaced apart from each other at any suitable distance suitable for cutting glass, and separate the arrays into discrete components 27 of substrate 20. While glass substrates may have particular suitability for certain end-use applications, it should be understood that substrate 20 can be a glass substrate, a silicon substrate, a ceramic substrate, a sapphire substrate, or any other substrate of any organic substrate or any suitable alternative material. In one example, when substrate 20 is a glass substrate, the glass may be substantially lead-free, including lead-free. In other examples, the glass may include lead.

[0081] The term “lead-free” as used herein, and its derivatives and similar phrases, may refer to the amount of lead contained as restricted under the Hazardous Substances Directive (RoHS). In one instance, the terms “lead-free,” “lead-free,” and their derivatives may mean a lead content of less than 0.1% by weight, including 0% by weight. Optionally or additionally, as used herein, the term “lead-free,” its derivatives, and similar phrases may mean a lead content of less than 0.1% by volume. In another instance, the term “lead-free,” its derivatives, and similar phrases as used herein may mean a lead content of less than one part per million (ppm).

[0082] At least one or more holes 26 can be configured as through-holes 28 extending from the first surface 22 through the substrate 20 to the second surface 24, such that the first surface 22 defines a first opening 23 of the through-hole 28, and the second surface 24 defines a second opening 25 of the through-hole 28. In other words, the through-hole 28 defines a first end at the first opening 23 and a second end at the second opening 25. Therefore, both the first and second ends of the through-hole 28 lead to the outer periphery of the substrate 20. The through-hole 28 can be straight and linear from the first opening 23 to the second opening 25. Alternatively, one or more portions of the through-hole 28 can be angled, curved, or define any suitable alternative non-linear shape.

[0083] Alternatively or additionally, at least one or more of the holes 26 may be configured as blind holes 30, which extend from one of the first surface 22 and the second surface 24 toward the other. Furthermore, the blind hole may terminate at a location spaced apart from the other of the first surface 22 and the second surface 24. Thus, the blind hole 30 opens at a first end onto one surface of the substrate 20 and is closed by the interior of the substrate 20 at a second end opposite the first end. In other words, the first terminal end of the blind hole 30 extends to one of the first opening 23 and the second opening 25 at the first surface 22 and the second surface 24, respectively, and the second end of the blind hole 30 is disposed between the first surface 22 and the second surface 24. However, it should be appreciated that the second terminal of the blind hole 30 may terminate at another hole 26 and thus be in fluid communication with both the first opening 23 and the second opening 25. Furthermore, the blind hole 30 may be linear or may have one or more segments angled relative to each other. One or more of the segments may include lateral components. The substrate 20 may include a sacrificial via extending from the blind via 30 to the outer surface of the substrate 20. For example, when the blind via 30 is directly on the first surface 22 of the substrate 20 or through another hole opening, the sacrificial via may extend from the closed end of the blind via 30 to the second surface 24.

[0084] Referring now to Figures 2A-2B, according to one example, one or more, or all, of the holes 26 may contain conductive material, thereby defining a conductive via 34. In one example, the conductive material may include a conductive filler 35 disposed in the respective one or more holes 26, thus the conductive filler 35 may at least partially define the conductive via 34. It will be understood from the following description that additional conductive material may be disposed in the holes 26 to further define the conductive via 34. An array 27 of holes including the conductive material shown in Figures 2A and 2B may thus define an array of vias. In this respect, it should be understood that a substrate 20 having conductive vias 34 may be referred to as an electrical component.

[0085] Specifically, a through-hole 28 containing conductive filler 35 can be described as defining a through-hole 36. A buried via 30 containing conductive filler 35 can be described as defining a buried via 39. Thus, the term "through-hole" and its derivatives as used herein can refer to one or both of through-holes 36 and buried vias 39. The conductive filler 35 can extend continuously from a first end of a via 34 to a second end of a through-hole 34. Thus, the conductive filler 35 can define a conductive path along the via 34 in the direction extending between the first end and the second end of the via. For example, the conductive path can be defined from the first end of the via 34 to the second end of the via 34. In this respect, it should be understood that when the via 34 is a through-hole 36, the first and second ends of the via 34 can be defined by a first opening 23 and a second opening 25. As will be understood from the following description, in some examples, the filler 35 may consist only of conductive material and air 41. Air 41 may include one or both of ambient air and an inert gas. For example, air 41 may be partially argon or pure argon. In another example, air 41 may be pure nitrogen.

[0086] Furthermore, in some examples, at least 50% of the via volume may consist solely of filler 35. For example, in some examples, 50% to 100% of the via volume may consist solely of filler 35. In particular, in some examples, 75% to 100% of the via volume may consist solely of filler 35. For example, 90% to 100% of the via volume may consist solely of filler 35. In particular, 95% to 100% of the via volume may consist solely of filler 35.

[0087] The substrate 20 may include at least one or more conductive redistribution layers 37. The redistribution layers may be applied to one or both of the first surface 22 and the second surface 24. The redistribution layers 37 extend over at least one of the conductive vias 34 and are thus electrically connected to the conductive filler 35. In one example, the substrate 20 may be configured as an electrical insertion layer, configured to electrically connect electrical contacts at each of the first surface 22 and the second surface 24, the electrical contacts being electrically connected to each other through the conductive vias 34.

[0088] The conductive filler 35 can be defined as any suitable highly conductive material to form the conductive via 34, as needed. As will be described in more detail below, the conductive material can be defined as sintered particles of a conductive material. In one example, the conductive material can be metallic. For example, the conductive material can be copper, gold, silver, aluminum, or any suitable alternative metal or alloy thereof, or other combinations thereof. Thus, the conductive material can include a copper alloy. Optionally or additionally, the conductive material can include a silver alloy. Optionally or additionally, the conductive material can include a gold alloy. Thus, in some examples, the conductive via 34 can be referred to as a metallized via 34. Similarly, the substrate 20 can be referred to as a metallized substrate. In one example, the conductive material can include silver-plated copper.

[0089] Alternatively, the conductive material can be non-metallic, such as a conductive polymer. The conductive material can also include any metal, or any suitable metal or conductive polymer coated on any suitable metal or non-metal particles, which can be conductive or non-conductive. As will be understood from the following description, the conductive via 34 can be adapted to conduct both direct current (DC) and radio frequency (RF) current. A conductive filler 35 can extend within the via 34 from a first end to a second end, such that the conductive material defines a conductive path from the first end to the second end. Therefore, when the via 34 is a through-hole 36, the conductive filler 35 can define a conductive path substantially from the first surface 22 to the second surface 24 of the substrate 20.

[0090] Referring now to FIG3, a method 40 is provided for conductively filling a hole 26 with a conductive filler 35 to form a conductive via 34. The method begins in step 42, wherein a substrate 20 and at least one suspension 60 of particles 62 suspended in a liquid medium are pre-set. Subsequently, in step 44, the at least one suspension may be stirred as needed to disperse the particles in the liquid medium.

[0091] Subsequently, in step 46, the orifice 26 may be filled with one or both of the particles and liquid medium of at least one suspension 60. It should be understood that, unless otherwise stated, the term "filling" as used herein with respect to suspension 60 includes at least partial filling or complete filling. The filling step can be achieved by performing a filling operation that forces the suspension into the orifice 26 under one or more pressures, which can be positive or negative pressure, centrifugal force, and electrostatic force. Filling step 46 may include one or more filling operations. In step 50, the particles are aggregated to increase the packing density of the particles in the orifice. Filling and compaction steps 46 and 50 define a filling and compaction sequence 55, which may be repeated as needed until the orifice 26 receives the desired amount of particles 62. However, in some examples, compaction step 50 may be omitted, as will be described in more detail below. In one example, the desired amount of particles 62 may substantially extend from a first end of the orifice 26 to a second end of the orifice 26. When the hole 26 is a through hole, the particle 62 can extend to one or both of the first surface 22 and the second surface 24 of the substrate 20. In some examples, the hole 26 can be overfilled by the particle 62, such that the particle 62 is filled beyond one or both of the first surface 22 and the second surface 24.

[0092] In step 52, the metal particles 62 are sintered to define a metal structure or a metal via. In some examples, method 40 may proceed from filling step 46 to sintering step 52 without performing the step of increasing the fill density 50. In step 53, the metal structure may undergo a compression step, whereby the metal structure is compressed at one or both of the first surface 22 and the second surface 24 of the substrate 20, thereby sealing the interface between the particles 62 and the substrate 20. As will be described in more detail below, the compression step may be an isostatic pressing step or a uniaxial or hard pressing step. In step 54, the via may be sealed if necessary. In some examples, step 54 may be omitted. Thus, the method may proceed from step 52 to step 565. As can be understood from the description below, the particles 62 may define an hermetically sealed seal together with themselves and the substrate 20, and the combination of sintered particles 62 and air may define a conductive fill. Finally, in step 56, at least one or more redistribution layers 37 are applied to one or both of the first surface 22 and the second surface 24 of the substrate 20. The steps of method 40 will now be described in more detail.

[0093] Referring now to Figures 1A-4A, method 40 begins at step 42, whereby substrate 20 is prepared together with at least one suspension of conductive particles 62 disposed in liquid medium 64. Step 42 may include manufacturing substrate 20 having the holes 26 shown in Figure 1, or preparing substrate 20 having holes 26. Furthermore, step 42 may include suspending the particles 62 in liquid medium 64, or preparing suspension 60.

[0094] As described above, the conductive particles 62 can be defined by any suitable conductive material as needed. For example, the conductive material can be a metal, such as copper, silver, or gold. Alternatively, the conductive material can be a combination of more than one metal. For example, one metal can be coated onto another metal. Optionally or additionally, the conductive material can be a conductive polymer. In one example, a metal can be coated with a conductive polymer. Alternatively, a conductive polymer can be coated onto one of the metals. It should be understood that one or more of the conductive metals and conductive polymers can be coated with any suitable material as needed. In one example, the conductive particles 62 can be silver particles. Optionally or additionally, the conductive particles 62 can be configured to include copper particles coated with silver. Optionally or additionally, the conductive particles 62 can be configured as copper particles without a coating layer.

[0095] In this regard, it is recognized that silver is a highly conductive metal. Furthermore, silver is a highly ductile metal, which can be useful during sintering. In particular, the inventors have discovered that the process of sintering silver does not cause the glass substrate with silver particles filling its vias to crack. Without being bound by theory, it is believed that the ductility of the silver particles allows the substrate 20 to expand and contract during and after sintering without compromising the structural integrity of the substrate 20. Simultaneously, silver exhibits sufficient strength properties. Furthermore, silver is a substantially non-porous metal, thereby enhancing the conductivity of the resulting conductive filler 35 in the vias 34. Optionally or additionally, as described above, particles 62 may be gold particles or particles of any suitable alternative material. Alternatively, as described above, particles 62 may be copper particles. While copper particles can be subjected to oxidation, it is believed that the oxide layer can be removed from the copper particles during the process described herein. For example, it is believed that at least a portion of the oxide layer of the copper particles can be removed under vacuum or centrifugal force, as described in more detail below. Furthermore, at least a portion until substantially all of the remaining oxide layer can be removed during sintering operations of the type described below. Therefore, it may be desirable to sinter copper under reducing conditions used for copper oxide in step 52.

[0096] As shown in Figure 7A, it may be desirable for the particles 62 to be substantially spherical, such that when they are filled, the particles 62 in the orifice 26 define respective gaps 66 between them (see, for example, Figure 7A), which can be combined to define at least one liquid flow path for draining the liquid medium 64 from the orifice 26, thereby leaving the particles 62 in the orifice 26. Thus, the term "substantially spherical" is used to recognize that the particles 62 may not be perfectly spherical, but they can approximate a spherical shape to the extent that the resulting gaps 66 define a reliable flow path. Therefore, the particles 62 can be any shape capable of defining the gaps 66 described herein. Thus, the particles 62 can have at least partially or completely arcuate, circular surfaces, or may alternatively or additionally include straight edges. Furthermore, it should be understood that when the orifice 26 is at least partially or completely filled with particles 62, the filler 35 may include orifices defined by the gaps 66. It should be understood that the gaps may define internal pores of the conductive material in the die orifice 26. In some examples, substantially all the holes of the conductive filler 35 may be defined by gaps. Unless otherwise stated, the terms “substantially,” “approximately,” and their derivatives, as well as words with similar meanings used herein with respect to value, size, shape, orientation, or location, may include said value, size, shape, orientation, and location, and a tolerance not exceeding 10% of said value or shape, or including tolerances of 8%, 5%, 3%, 2%, and 1%.

[0097] Furthermore, as described in more detail below, it is desirable that the conductive particles 62 be microcrystal-controlled, allowing the particles 62 to be sintered without substantial densification. While it may be desirable that the silver or copper be as pure as possible, thus free of organic material, it should be recognized that the methods used to produce substantially spherical silver or copper and microcrystal particles 62 can produce particles with traceable amounts of organic material. Therefore, substantially pure material used relative to the material of particles 62 can mean a pure material with a purity greater than 90% by weight. In one example, particles 62 can be a pure material with a purity greater than 95% by weight. For example, particles 62 can be a pure material with a purity greater than 98% by weight. That is, particles 62 may be free of more than 2% by weight of organic impurities. For example, the particles can be a pure material of about 98.3% by weight. Otherwise, in one example, substantially pure particles 62 can mean containing 10% or less organic material by weight, such as less than 5% organic material, and in one example less than 2% organic material; for example, the particles may have an organic material content of about 1.7% by weight. In one example, solid particles 62 have a porosity of no more than about 5% by volume.

[0098] Therefore, although the conductive material may include a small amount of organic material as described above, it can be said that the resulting via 34 may consist only of conductive material and air. It can also be said that the resulting via 34 may consist essentially of conductive material and air. As described above, in some examples, the conductive material may be a metal such as silver or copper, but may also be other materials as contemplated herein. Alternatively, silver or copper may be mixed with a conductive polymer to achieve greater conductivity in the air gap. Furthermore, the particles 62 may be substantially non-porous, thereby providing a highly conductive path from the first end of the via to the second end of the via in the sintered matrix produced after sintering. In one example, the via can conduct both direct current and radio frequency (RF) current at desired rates.

[0099] For example, the conductive via 34 can conduct radio frequency signals along its entire length, wherein the insertion loss at an operating frequency of approximately 20 GHz does not exceed approximately -0.15 dB. For example, in some examples, the insertion loss at an operating frequency of approximately 20 GHz may not exceed approximately -1 dB. For example, in some examples, the insertion loss at an operating frequency of approximately 20 GHz may not exceed approximately -0.5 dB. For example, in some examples, the insertion loss at an operating frequency of approximately 20 GHz may not exceed approximately -0.3 dB. For example, in some examples, the insertion loss at an operating frequency of approximately 20 GHz may not exceed approximately -0.1 dB. The term "not greater than" in this context is used to indicate a negative value not less than the stated decibel.

[0100] In one example, the liquid medium can be any suitable liquid medium that can suspend the conductive particles 62. In one example, the liquid medium 64 can be an alcohol. In particular, the alcohol can be one of isopropanol, ethanol, and methanol. In this respect, it should be appreciated that metals such as silver and copper can have a zeta potential or surface charge. Therefore, the metal particles can potentially agglomerate with each other. Furthermore, the particles can interact with a substrate that can be electrostatically charged, for example, when the substrate is a glass substrate, and interact with each other. The alcohol can be slightly polar and can therefore be configured to neutralize the zeta potential of the particles 62. Further, the particles 62 can be coated with an organic anti-caking agent to prevent the particles from agglomerating in the liquid medium 64. The anti-caking agent can be defined as a fatty acid. For example, the fatty acid can be oleic acid. Alternatively, the fatty acid can be stearic acid.

[0101] The size of particle 62 can be determined as needed. It should be understood that the size of particle 62 is large enough that the void 66 defines a reliable liquid flow path to drain liquid from the hole 26 of the substrate 20, leaving conductive material in the hole 26. However, it may be desirable that the size of particle 62 be small enough that the resulting via 34 contains a suitable amount of conductive material from the particle to define a reliable electrical path from the first end of the via to the second end. In one example, particle 62 may have an average size in the range of about 1 micrometer to about 10 micrometers, for example, about 2 micrometers to about 10 micrometers. In one example, the average size of particle 62 may be in the range of about 2 micrometers to about 4 micrometers. In another example, the average size of particle 62 may be in the range of about 2.5 micrometers to about 3.5 micrometers.

[0102] However, it is recognized that auxiliary conductive material can be added to the gaps 66 of the particles 62 as part of the conductive filler after the liquid medium 64 has been emptied. In particular, it is conceivable that the auxiliary conductive material can be added prior to sintering. Alternatively or additionally, it is conceivable that the auxiliary conductive material can be added after sintering. A reliable electrical path can be configured to reliably conduct one or both of the DC current and the RF current as described above. In one example, the particles 62 of the suspension 60 may have an average size ranging from about 1 micrometer to about 10 micrometers, such as from about 2 micrometers to about 10 micrometers. In one example, the average size of the particles 62 may range from about 2 micrometers to about 4 micrometers. In another example, the average size of the particles 62 may range from about 2.5 micrometers to about 3.5 micrometers.

[0103] In one example, the conductive filler 35 may comprise molten particles of different sizes. In one example, the particles may be fused together during a sintering operation. For example, at least one suspension 60 may comprise a first suspension 60a and a second suspension 60b. The first suspension 60a may comprise a plurality of first particles 62a suspended in a liquid medium 64, as shown in FIG4b. The second suspension 60b may comprise a plurality of second particles 62b suspended in a liquid medium 64, as shown in FIG4c. The first particles 62a may comprise any suitable conductive material described herein. Similarly, the second particles 62b may comprise any suitable conductive material described herein. In one example, the first particles 62a and the second particles 62b are defined by corresponding materials that may be the same material. In another example, the first particles 62a and the second particles 62b are defined by corresponding materials that may be different materials. As will be understood below, in some examples, the conductive filler may comprise a body portion filling of the first particles 62a and port filling of the second particles 62b extending from the body portion filling to the first and second ends of the through-hole. The main body filler can extend along a central region of the through-hole, extending from a first end to a second end of the through-hole, including the center of the through-hole. Furthermore, the main body filler can extend along most of the through-hole.

[0104] When the first particle 62a and the second particle 62b are made of the same material, the material can be a single homogeneous material from the first end of the hole 26 to the second end of the hole 26. When the hole 26 is a through hole, the material can be said to be a single homogeneous material substantially from the first surface 22 of the substrate 20 to the second surface 24 of the substrate 20. When the material is metal, the metal can be said to be a single homogeneous metal substantially from the first surface to the second surface. Alternatively, the respective materials of the first and second particles 62a and 62b can be different materials. Furthermore, the liquid medium 64 of the first and second suspensions 60a and 60b can be any suitable liquid medium as described herein. The liquid medium 64 of the first suspension 60a can be the same liquid medium as or a different liquid medium from the liquid medium of the second suspension 60b.

[0105] In one example, the first particle 62a may have a first average particle size in the range of about 1 micrometer to about 10 micrometers, such as about 1.2 micrometers. In one example, the average size of particle 62 may be in the range of about 2 micrometers to about 4 micrometers. In another example, the average size of particle 62 may be in the range of about 2.5 micrometers to about 3.5 micrometers.

[0106] The second particle 62b may have an average particle size smaller than that of the first particle 62a. Therefore, it can be said that the first particle 62a has a first average particle size, the second particle 62b has a second average particle size, and the first average particle size is greater than the first average particle size. In one example, unless otherwise stated, the first average particle size may be in the range of about 5 to about 120 times the second average particle size. In one example, the first average particle size may be in the range of about 5 to about 20 times the second average particle size. For example, the first average particle size may be in the range of about 10 to about 15 times the second average particle size.

[0107] In one example, unless otherwise specified, the second average particle size may range from about 0.01 micrometers to about 1 micrometer. For example, the second average particle size may range from about 0.05 micrometers to about 0.05 micrometers. Specifically, the second average particle size may range from about 0.15 to about 0.75 micrometers. Specifically, the second average particle size may range from about 0.15 micrometers to about 0.5 micrometers. In one example, the second average particle size may range from about 0.15 micrometers to about 0.3 micrometers. For example, the second average particle size may be about 0.22 micrometers.

[0108] Unless otherwise stated, references to particle 62a and particle 62b herein are intended to apply to each of the first particle 62a and the second particle 62b. Similarly, unless otherwise stated, references to liquid medium 60 herein are intended to apply to the liquid medium of each of the first suspension 60a and the second suspension 60b. Likewise, references to suspension 60 herein are intended to apply to each of the first suspension 60a and the second suspension 60b, unless otherwise stated.

[0109] The viscosity of one or both of the first and second suspensions 60a and 60b may be less than the viscosity of conventional pastes used to metallize vias in glass substrates. The viscosity of one or both of the first and second suspensions 60a and 60b may be in the range of about 1 centipoise to about 1000 centipoise. For example, this range may be from about 1.5 centipoise to about 50 centipoise. In another example, this range may be from about 1.8 centipoise to about 15 centipoise. For example, this range may be between about 1.9 centipoise and about 5 centipoise.

[0110] The first suspension 60a may have a solid concentration of first particles 62a ranging from about 0.1% to about 20% by weight. In one example, this range may be from about 1% to about 15%. For example, this range may be from about 1% to about 10%. In one instance, the solid concentration may be about 5%. In another example, the solid concentration may be about 10%. Optionally, the first suspension 60a may have any suitable alternative solid concentration as needed. The second suspension 60b may have a solid concentration of second particles 62b ranging from about 0.1% to about 10% by weight. In one example, this range may be from about 1% to about 5%. For example, this range may be from about 1% to about 4%. In one example, the solid concentration of the second suspension 60b may be about 2%. In another example, the solid concentration may be about 10%. Optionally, the second suspension 60b may have any suitable alternative solid concentration as needed. In this regard, it should be understood that any concentration of solid particles above zero may allow the corresponding liquid medium to allow the particles to flow into the orifice 2626.

[0111] It should be recognized that one or both of the first suspension 60a and the second suspension 60b may include an anti-caking agent to reduce the agglomeration of the first particles 62a and the second particles 62b, respectively. The reduction of agglomerates can lead to an increase in particle density in the pore 26, allowing particles to fill the pore 26 at a faster rate than without an anti-caking agent. In a non-limiting example, the anti-caking agent may be oleic acid added during sintering. Although a traceable amount of residual material remains after sintering, it is considered that the residual material is not in sufficient quantity to meaningfully affect the electrical properties of the through-hole 34. Therefore, when an anti-caking agent is added to one or both of the suspensions 60a and 60b, the through-hole 34 can still be considered to consist essentially only of conductive material and air, as shown in Figure 2b; it can also be said that the through-hole 34 is essentially composed of conductive material and air.

[0112] Referring to Figure 7A, particle 62 can define a monomodal distribution 70. Not intended to be limiting, unless otherwise stated herein, in a monomodal distribution 70, particle 62 can be within ±100% of the average particle size. For example, this range could be ±50% of the average particle size.

[0113] In one instance, unless otherwise specified in the claims, the first particle 62a may define a unimodal distribution 70, which may have an average size in the range of about 1 micrometer to about 10 micrometers, for example, about 1.2 micrometers. For example, the average particle size of the first particle 62a may be in the range of about 1 micrometer to about 6 micrometers, for example, about 1.4 micrometers. Unless otherwise specified, the terms “approximately” and “substantially” used herein with respect to size and shape may be interpreted as indicating a range of variation of up to 10% of the value or shape. In one example, the average size of the first particle 62a may be in the range of about 2 micrometers to about 4 micrometers. In another example, the average size of particle 62a may be in the range of about 2.5 micrometers to about 3.5 micrometers.

[0114] Furthermore, unless otherwise specified in the claims, the second particle 62b may define a single-mode distribution 70 having an average particle size smaller than that of the first particle 62a. Thus, it can be said that the first particle 62a has a first average particle size, the second particle 62b has a second average particle size, and the first average particle size is greater than the second average particle size. In one instance, unless otherwise stated, the first average particle size may be in the range of about 1.5 times to about 120 times the second average particle size. In some embodiments, in one example, the first average particle size may be in the range of about 5 times to about 20 times the second average particle size. For example, the first average particle size may be in the range of about 10 times to about 15 times the second average particle size.

[0115] Referring now to Figure 7B, the first particle 62a of the first suspension 60a can alternatively be defined as a bimodal distribution 72, the bimodal distribution of the first particle 62a having a greater filling density of conductive particles in the via 34 than the single-modal distribution. The filling density can be defined as the density of particles in the via 34. Therefore, it is conceivable that, in some examples, the via 34 generated by the bimodal distribution can have a greater conductivity than the via 34 generated from the single-modal distribution.

[0116] The first particle 62a may include a plurality of first bimodal particles 74 and a plurality of second bimodal particles 76. The first bimodal particles 74 may have a first bimodal average particle size as described above with respect to the first particle 62a with a single-mode distribution. Therefore, the first bimodal particles 74 may define the aforementioned gap 66. The second bimodal particles 76 may have a second bimodal average particle size smaller than the first bimodal average particle size of the first bimodal particles 74. As shown, the size of the second bimodal particles 76 may be configured to fit within corresponding gaps in the gaps 66 defined by the first bimodal particles 74. In one example, the second average particle size of the bimodal particles 76 may be in the range of about 0.3 micrometers to about 1 micrometer; for example, the second average particle size may be about 0.6 micrometers.

[0117] In some examples, it may be desirable to maximize the size of the second bimodal particles 76 such that they fit into the corresponding voids in the void 66 without expanding the void 66. However, it should be understood that the second bimodal particles 76 can expand the void 66, while simultaneously increasing the density of the first particles relative to the monomodal distribution. In any case, the first bimodal particles 74 and the second bimodal particles 76 can be said to constitute a combination to define a second bimodal void 75, which is smaller than the void 66 that may be referred to as the first bimodal void. Furthermore, the second bimodal void 75 may be disposed within the first bimodal void 66.

[0118] Unless otherwise stated, and not intended to be limiting, the ratio of the first bimodal particle size to the second bimodal average particle size may be defined in the range of about 4:1 to about 10:1. For example, this ratio may be about 7:1. In other examples, this ratio may be in the range of about 1.5:1 to about 12:1, for example, in the range of about 1.5:1 to about 3.5:1. The size of the gap 66 containing the bimodal particles 74 is kept large enough to define a liquid flow path together with the bimodal void 66 to drain the liquid medium 64 from the hole 26 of the substrate 20, while the bimodal void 66 is small enough that the resulting orifice 34 contains a suitable amount of conductive material of the particles to define a reliable electrical path. It should be understood that, if desired, the second particles 62b of the second suspension 60b may also define a bimodal distribution. In particular, one or both of the first particles 62a and the second particles 62b may include a bimodal distribution. The amount of the second bimodal particle 76 can be in the range of about 5% to about 20% of the pore volume. For example, this amount can be about 10 percent of the pore volume. It should be understood that including the second bimodal particle 76 can reduce the viscosity of the suspension during filling step 46 and can result in a higher green density at the filling.

[0119] It should be understood that a bimodal distribution can achieve a higher fill density than a single bulk filler before sintering. Therefore, the resulting conductive filler can have a higher density. The second bimodal particle 76 can be a different metal than the first bimodal particle 74. The second bimodal particle can be any suitable metal. In one example, the second bimodal particle 76 can have a melting point lower than that of the first bimodal particle. In one example, the second bimodal particle 76 can include indium. In another example, the second bimodal particle 76 can include tin. The bimodal particle 76 can form an intermetallic compound or alloy with the first bimodal particle 74 for transient liquid phase sintering. Furthermore, transient liquid phase sintering can result in template / shape retainer cavity configuration remnants left from the second bimodal particle 76. The resulting cavity structure and associated porosity can be adjusted to achieve desired RF and DC conductivity in the resulting vias. Specifically, the pore structure can be at least partially based on the amount of the second bimodal particles 76 and the tunable average particle size of the second bimodal particles 76. Alternatively, if desired, one or both of the volume and average particle size of the second bimodal particles 76 can be controlled to eliminate continuous porosity from the first end to the second end. Furthermore, the transient liquid phase can result in less organic contamination, better wall adhesion of the pore filling, and more controllable pore geometry.

[0120] It was further recognized that the alloy could be temperature stable during the subsequent RDL step. In particular, the sintering step caused the second bimodal particle 76 to melt and liquefy within the first bimodal particle 74, resulting in an alloy with a melting point higher than the melting point at which the RDL layer temperature was applied.

[0121] In one example, during the compaction step, the holes can be filled with bimodal particles 60a. Furthermore, bimodal particles 60a are less compressible than single-mode fillers. Therefore, it is conceivable that a coating can be applied to the ends of the vias and the outer surface of the substrate. Additionally, a redistribution layer can be applied with or without a coating.

[0122] It should be understood that the bimodal particles 60a can be filled to the level outside the outer surface of the substrate. Specifically, a sacrificial layer can be applied to the outer surface of holes aligned with the holes in the board. Thus, the sacrificial layer extends along a length that effectively increases the length of the holes. Therefore, the holes in the substrate can be filled, and the holes in the sacrificial layer can be filled at least partially or completely. The sacrificial layer can be removed before or after filling. It is conceivable that, after the sintering step, the pressed filler can be substantially coplanar with the outer surface of the substrate. Therefore, a redistribution layer, alone or in combination with plating, can be applied to the sintered filler 35 without performing port filling. Optionally, port filling can be performed if desired, as described in more detail below.

[0123] Alternatively, the conductive layer can be applied to one or both outer surfaces of the substrate prior to filling the vias. The conductive layer can also extend along the inner walls of the vias. For example, the conductive layer can extend along one or both outer regions of the inner walls. In one example, the conductive layer could be titanium. It is conceivable that the filler 35 can be bonded to the conductive layer during the sintering step to form a hermetically sealed layer.

[0124] Referring now to Figure 7C, the first particles 62a of the first suspension 60a can alternatively be defined as a trimodal distribution 73, which may have a greater density of conductive particles in the vias 34 than the bimodal distribution, and therefore also greater than the unimodal distribution. Thus, it is conceivable that, in some examples, the vias 34 generated by the trimodal distribution 73 may have a higher conductivity than the vias 34 generated from each of the bimodal and unimodal distributions.

[0125] The first particle 62a may include a plurality of first bimodal particles 74 defining the first trimodal particle as described above, a plurality of second bimodal particles 76 defining the second trimodal particle as described above, and a plurality of third trimodal particles 78, and the first trimodal particle 74 may have a first trimodal average particle size as described above with respect to the first particle 62a with a single-modal distribution. Therefore, the first trimodal particle 74 may define the aforementioned gap 66. The gap 66 of the trimodal distribution 73 may be referred to as the first trimodal gap. The second trimodal particle 76 may have a second trimodal average particle size smaller than the first bimodal average particle size of the first trimodal particle 74, as described above with respect to the first bimodal particle and the second bimodal particle. Therefore, the size of the second trimodal particle 76 may be set to fit within the first trimodal gap 66 to define the second trimodal gap 75 as described above.

[0126] Furthermore, third trimodal particles 78 can be filled in the holes 26 to be arranged in the second trimodal gaps 75. As shown, the size of the third trimodal particles 78 can be configured to fit into the corresponding three modal gaps 75 defined by the first trimodal particles 74 and the second trimodal particles 76 in the second trimodal gaps 75. In some examples, it may be desirable to maximize the size of the third trimodal particles 78 so that they fit into the corresponding one of the second trimodal gaps 75 without expanding the gap 75. However, it should be understood that the third bimodal particles 78 can expand the second trimodal gap 75 while increasing the density of the first particles 62a relative to the bimodal distribution. In any case, the first and second and third bimodal particles 76 and 78 can be configured to form a combination to define a third trimodal gap 69 smaller than the second trimodal gap 75.

[0127] The third trimodal particle 78 may have a third trimodal average particle size smaller than the second trimodal average particle size. Although, unless otherwise stated, the second trimodal average particle size and the third trimodal average particle size may be defined in a ratio ranging from about 4:1 to about 10:1, for example, this ratio may be about 7:1. It should be understood that, if desired, the second particle 62b of the second suspension 60b may also define a trimodal distribution. Therefore, one or both of the first and second particles 62a and 62b may define a trimodal distribution. Alternatively, if desired, a trimodal distribution may exist in a single solution.

[0128] When the second particle 62b defines a multimodal distribution, such as a bimodal or trimodal distribution, and the second particle 62b defines port filling, the bimodal distribution can create an hermetically sealed area at one or both of the first and second additives of the conductive filler 35, as described below.

[0129] In one example, the third trimodal particle 78 can be made of any suitable conductive material. For example, the third trimodal particle 78 can be made of the same material as the first trimodal particle 74; therefore, in one example, the third trimodal particle 78 can be made of silver. During the sintering step, the second trimodal particle 76 can transport the third trimodal particle 78 during the transient liquid phase.

[0130] Referring again to Figures 1A through 4C, it is conceivable that filler 35 may have a porosity between about 10% and about 60% by volume. For example, the porosity may be between about 20% and about 50%. The porosity may depend on several factors, including particle size, the nature of the particle size distribution (e.g., single-mode, dual-mode, or tri-mode), and any conductive additives that may be added to the conductive material before or after sintering. In other examples, it should be appreciated that particle 62 may be provided as a four-mode distribution. In other examples, it should be appreciated that particle 62 may be provided as a five-mode distribution. Thus, particle 62 comprising either or both of the first particle 62a and the second particle 62b may be provided as any suitable multimodal distribution of particles.

[0131] It should be understood that the hole 26 may include a body portion filler and a port filler. The body portion filler may be defined at least partially or entirely by the first particle 62a described above. The port filler may be defined at least partially or entirely by the second particle 62b described above. The body portion filler may occupy a first portion of the hole 26 or through-hole, and the port filler may occupy a second portion of the hole 26 or through-hole that is different from the first portion. For example, the body portion filler may occupy an inner portion of the hole 26 or through-hole, and the port filler may occupy an opposite outer region of the hole 26 or through-hole. Thus, the port filler may extend from the body portion filler to each of the opposite ends of the hole 26 or through-hole. For example, when the hole or through-hole is a through-hole or a through-through-hole, the port filler may extend from each of the first surface 22 and the second surface 24 of the substrate 20 to each of the first surface 22 and the second surface 24 of the substrate 20. Therefore, it can be said that the conductive filler 35 may include one or both of the body portion filler and the port filler. In one example, the body portion filler may be defined by a first particle 62a. In another example, the port filler may be defined by a second particle 62b. Alternatively, both the body portion filler and the port filler may be defined by the first particle 62a as needed. In this regard, it should be appreciated that method 40 may include multiple steps of filling the body portion holes. One or more steps of batch filling may be performed using a first particle 62a of one of the single-mode, dual-mode, and tri-mode distributions, and one or more other steps of body portion filling may be performed using first particles of different single-mode distributions among the single-mode, dual-mode, and tri-mode distributions. Alternatively, all body portion filling steps may be performed using a first particle of the same one of the single-mode, dual-mode, and tri-mode distributions.

[0132] The body portion of the filler may occupy the length of the hole 26 or the guide hole, the length of which is approximately 50% to 100% of the total length of the hole 26 or the guide hole. For example, the body portion of the filler may occupy the length of the hole 26 or the guide hole, the length of which is approximately 80% to approximately 100% of the total length of the hole 26 or the guide hole. Specifically, the body portion of the filler may occupy the length of the hole 26 or the guide hole, the length of which is approximately 90% to approximately 99% of the total length of the hole. In one example, the body portion of the filler may occupy the length of the hole or the guide hole, the length of which is approximately 94% to approximately 99% of the total length of the hole 26 or the guide hole 34. In a specific example, the body portion of the filler may occupy the length of the hole or the guide hole, the length of which is approximately 96% to approximately 98% of the total length of the hole 26 or the guide hole. A port filler may extend from the body portion of the filler to a first end of the hole 26 or the guide hole. Furthermore, the port filler may extend from the body portion of the filler to a second end of the hole 26 or the through hole. Furthermore, in one example, the portion of the hole occupied by the port filler is not occupied by the body portion filler. In a specific example, the port filler may occupy a length ranging from approximately 1% to approximately 4% of the total length of the guide hole 34 at each of the first and second ends.

[0133] The inventors recognize that conductive particles 62 may tend to settle in the liquid medium 64, especially if stored for a long period of time, as shown in FIG4A. Therefore, in step 44, and as shown in FIG4B-4C, the suspension 60 may be agitated to disperse particles 62 in the liquid medium 64. For example, in one example, the suspension may be sonicated to disperse particles 62 in the liquid medium 64. Thus, it is understood that the liquid medium 64 is configured to support particles 62 as a dispersion 68. Therefore, it should be understood that the liquid medium can be any liquid suitable for supporting particles 62 to fill at least one aperture 26 of the substrate with particles 62 according to the method described herein.

[0134] Subsequently, in step 46, the hole 26 can be filled with at least one suspension 60. As will be understood from the description below, the suspension 60, and therefore the particles 62, can be propelled into the hole 26 under a force defined by the pressure difference on the substrate 20 as shown in Figures 5 and 10. The pressure difference can be defined by a fluid pressure difference. The fluid pressure difference can be a gas pressure difference. In one example, the gas can be air, so the gas pressure difference is an atmospheric pressure difference. For example, the atmospheric pressure difference can be defined by a vacuum force. Thus, a vacuum device can be used to propel the particles 62 into the hole 26 under vacuum pressure. Alternatively, the atmospheric pressure difference can be defined by positive pressure. Optionally or additionally, the force propelling the particles 62 into the hole 26 can be a centrifugal force, for example using a centrifuge as described below with respect to Figures 19A to 19E, or additionally, the force propelling the particles 62 into the hole 26 can be an electrostatic force as described below with reference to Figures 20A-20F.

[0135] Step 46 of filling orifice 26 under air pressure in one example will now be described with reference to Figures 5 to 6B. Specifically, a fluid pressure filling device 82 is configured to apply a pressure differential over the suspension 60, which forces the suspension 60 into orifice 26. For example, the fluid pressure filling device 82 can be configured as an air pressure filling device, which is configured to apply a pressure differential over the suspension 60 that forces the suspension 60 to flow into orifice 26. In one example, the air pressure filling device 82 can be configured as a vacuum filling device 84, which is configured to apply a vacuum pressure to the suspension 60 that generates the pressure differential. In another example, the vacuum filling device 82 can be modified to apply forced air to the suspension 60 that generates the pressure differential under positive pressure. It will be understood that the suspension will be forced to flow in a direction from higher pressure to lower pressure.

[0136] As shown in Figure 5, the vacuum filling device 84 may include a frame 86 that defines at least partially an inner cavity 88 of a vacuum chamber 90. The frame 86 includes a frame body 87 that defines an opening 92 leading to the inner cavity 88. At least a portion of the substrate 20, particularly the orifice 26, is in fluid communication with the vacuum chamber 90. Furthermore, the substrate 20 is sealed to the frame 86 such that a vacuum pressure is applied to the substrate 20 without drawing any significant amount of air through the interface between the substrate 20 and the frame 86 into the inner cavity, and further, the orifice 26 is provided. The vacuum filling device 84 may include a gasket 94 that seals the substrate 20 to the frame 86 against airflow at the interface between the substrate 20 and the frame 86. For example, the gasket 94 may extend through the interface between the substrate 20 and the frame 86. The gasket 94 may be made of any suitable material as needed. For example, the gasket 94 may be made of rubber. In one example, gasket 94 can be vulcanized rubber. In particular, gasket 94 can be room temperature vulcanized silicone (RTV silicone).

[0137] Frame 86 may include a frame body 87 and a shelf 96, the shelf 96 being attached to the frame body 87 to directly or indirectly support at least a portion of the substrate 20. Shelf 96 may close a portion of the opening end 92. For example, shelf 96 may close the outer periphery of the opening end 92. Vacuum filling device 84 may include a sealing member 98. Sealing member 98 may define a non-porous interface relative to the airflow between shelf 96 and frame body 87 when vacuum chamber 90 is under negative pressure. It should be understood that shelf 96 may be integral with frame body 87. Frame body 87 may define an outlet 91 configured to connect to a vacuum source to generate negative pressure in vacuum chamber 90, whereby frame body 87 and shelf 96 may be substantially non-porous relative to the airflow passing through them when vacuum chamber 90 is under negative pressure.

[0138] The vacuum filling device 84 may further include a filter medium 100 positioned between at least a portion of the substrate 20 and the vacuum chamber 90. For example, the filter medium 100 may be aligned with an opening receiving the suspension 60, and may be porous relative to the air and liquid medium 64, but non-porous relative to the particles 62. Thus, both the air and liquid medium 64 can pass through the filter medium, while the particles 62 are retained in the pores 26. A gasket 94 may further seal the substrate 20 to the filter medium 100 relative to airflow at the interface between the substrate 20 and the filter medium 100. Thus, a first interface 102 between the substrate 20 and the filter medium 100 is sealed relative to the airflow therebetween, and a second interface 104 between the filter medium 100 and the frame 86 is sealed relative to the airflow therebetween. It should be understood that the same gasket 94 may seal each of the first interface 102 and the second interface 104. Optionally, the first gasket can seal the first interface 102, and the second gasket, which is separate from the first gasket, can seal the second interface 104. Therefore, it can be said that at least one gasket seals the first interface 102 and the second interface 104.

[0139] The filter media 100 can be made of any suitable material suitable for allowing liquid media 64 and air to pass through while preventing particles 62 from passing through. Filter media include glass microfibers, cellulose, mixed cellulose esters (MCE), cellulose acetate, cellulose nitrate, polytetrafluoroethylene (PTFE), polyamide, polyimide-imide, polyethersulfone, polyvinylidene fluoride, polyacrylonitrile polyvinyl difluoride, phenol-formaldehyde, WPP, WLP, HVLP, and many commercially available filter membrane types, such as those sold by companies like Millipore, Membrane Solutions, Whatman, and Ahlstrom, and under trade names such as Durapore, Expressplus, Isopure, etc.

[0140] Since the first interface 102 and the second interface 104 are sealed, all or all of the vacuum pressure in the vacuum chamber 90 can be applied to the hole 26 of the substrate 20. It should be understood that the gasket 94 prevents airflow through the substrate 20 at the exclusion region 106 covered by the gasket 94; therefore, it may be desirable to manufacture the substrate 20 without openings at the exclusion region 106. In one example, the exclusion region 106 may be located at the outer periphery of the substrate 20, but it should be understood that the exclusion region 106 can be defined anywhere on the substrate 20 covered by at least one gasket 94.

[0141] The vacuum filling apparatus 84 may further include a support member 108 configured to directly or indirectly support at least a portion of the substrate 20. Specifically, the support member 108 may be aligned with an aperture 26 of the substrate 20 that will receive the suspension 60 under induced pressure differential. The support member 108 may be supported by a frame 86 extending across at least a portion of the opening end 92 to the entire opening end 92. Specifically, the support member 108 may be supported by a shelf 96. Furthermore, since the filter medium 100 is aligned with the aperture 26, the filter medium 100 is similarly aligned with the support member 108. In one example, the filter medium 100 may be disposed between the substrate 20 and the support member 108. Specifically, the filter medium 100 may rest on the support member 108, and the substrate 20 may rest on the filter medium 100.

[0142] Each of the substrate 20, filter medium 100, and support member 108 defines an inner surface 97 facing the vacuum chamber 90 and an outer surface 99 opposite to the inner surface 97. The outer surface 99 of the substrate 20 may be defined by one of the first surface 22 and the second surface 24. The inner surface 97 of the substrate 20 may be defined by the other of the first surface 22 and the second surface 24. At least a portion of the inner surface of the support member 108 may open into the vacuum chamber 90. At least a portion of the inner surface of the filter member 100 may rest on at least a portion of the outer surface of the support member 108. At least a portion of the inner surface 97 of the substrate 20 may rest on at least a portion of the outer surface of the filter member 100. A gasket 94 may rest on the outer surface 99 of the substrate at the exclusion zone 106. Therefore, each hole 26 receiving the suspension 60 can be aligned with each of the filter member 100 and the support member 108 with respect to the length of the hole 26, the length of which is aligned with the direction of the hole 26 defining the pressure difference.

[0143] The support member 108 can be made of any suitable material that is porous relative to the air and the filter medium 100. In particular, the support member 108 can have a porosity greater than that of the filter medium 100. Therefore, both air and the filter medium can pass through the support member 108. In a non-limiting example, the support member 108 can be defined as sintered glass (also known as glass frit). Therefore, the support member 108 can be a rigid support member.

[0144] During operation, a volume of suspension 60 is applied to the outer surface 99 of substrate 20 such that the suspension covers at least a portion of the outer surface 99. For example, suspension 60 may be coated onto the outer surface 99. During batch filling operations, suspension 60 may be defined by a first suspension 60a. As will be understood from the following description, during port filling operations, suspension 60 may be defined by a second suspension 60b; however, it should be understood that particles of other sizes may be sufficient for port filling. For example, first suspension 60a may be used for port filling.

[0145] Specifically, the suspension 60 is applied to a filling area of ​​the substrate 20, which may be defined by holes 26 aligned with the filter medium and support member 108, so that the suspension 60 can cover the holes 26 to be filled. For example, the suspension 60 may extend over and through the holes 26. Optionally or additionally, as described in more detail below, the suspension 60 may be guided to flow along the holes 26 along the outer surface 99 of the substrate 20.

[0146] The filling step 46 may include applying the suspension 60 to the outer surface 99 of the substrate 20. A vacuum source may be activated to apply negative pressure to the vacuum chamber 90. It should be understood that the vacuum source may be activated during or after the suspension 60 has been applied to the substrate 20, or before the suspension 60 is applied to the substrate 20.

[0147] Referring now to FIG. 6A, negative pressure pushes the suspension 60 from the outer surface 99 of the substrate 20 into the corresponding hole 26 leading to the outer surface 99 of the substrate. As described above, the filter medium 100 extends across the inner surface 97 of the substrate 20 and through the hole 26. Since the filter medium 100 and the support member 108 are porous relative to air, the negative pressure in the vacuum chamber 90 creates a pressure difference across the hole 26, which can be set as a negative pressure that draws the suspension 60 into the hole 26. Therefore, both the liquid medium and the particles 62 suspended in the liquid medium 64 flow into the hole 26 under the pressure difference. Since the filter medium 100 is porous relative to the liquid medium 64 but non-porous relative to the particles 62, the pressure difference causes the liquid medium 64 to flow through the filter medium 100. Since particles 62 cannot flow through the filter medium 100, they remain in the holes 26, and thus are collected in the holes 26 when the liquid medium 64 flows through them. Furthermore, because the filter medium 100 can plane against the inner surface 97 of the substrate 20, particles 62 can accumulate against the filter medium 100 and therefore can be substantially flush with the inner surface 97 of the substrate 20. Additionally, when all filling steps are completed, the particles can be substantially flush with the outer surface 99, or the particles 62 can fill beyond the outer surface 99 of the substrate 20. Particles 62 disposed beyond the outer surface 99 can be removed from the outer surface by driving a rod, for example, on the outer surface 99 of the substrate 20.

[0148] As described above, depending on the nature of the particle size distribution, the hole 26 can be a through hole, such that one or both of the negative pressure from the outer surface 99 of the substrate 20 to the inner surface 97 of the substrate 20 and the liquid medium 64 cause the particles 62 to stack on top of each other, thereby defining the above reference. FIGS. 7A-7COne or more voids of the type described herein. Specifically, a vacuum force applied to the inner surface 97 of the substrate 20 can draw the suspension from the outer surface into the hole 26. Optionally, a positive pressure applied to the outer surface 99 can cause the suspension to flow toward the inner surface 97 into the hole 26, and the liquid medium of the suspension can be drained from the through hole 26. Alternatively, if the hole 26 is a blind hole of the type described above, a sacrificial hole can extend from the blind hole to the outer surface of the substrate 20 to form a through hole. Thus, conductive particles 62 can be forced into the blind hole and the sacrificial hole under the action of one or more of pressure difference, centrifugal force, and electrostatic force. To prevent the sacrificial hole from acting as a conductive via, an electrically insulating cap can be used to cover the sacrificial hole at a location adjacent to the second surface 24. Therefore, the redistribution layer will not be electrically connected to the metal in the sacrificial hole. As described herein, the electrically insulating cap can seal the sacrificial hole to provide hermeticity to the sacrificial hole. Alternatively or additionally, at least some or all of the metal can be removed from the sacrificial hole. For example, a laser can ablate the metal in the sacrificial hole without removing metal from the blind hole. Alternatively or additionally, sacrificial vias can be etched to remove metal from the sacrificial vias without removing metal from the blind vias. Alternatively or additionally, the redistribution layer can avoid contact with the metal in the sacrificial vias at, for example, the second surface 24.

[0149] It should be recognized that in practice, particles 62 may not necessarily be as highly packed as those schematically shown in Figures 7A to 7C. Therefore, the resulting void size can be larger than that shown in Figures 7A to 7C. This allows the liquid medium 64 to flow through particles 62 at a greater flow rate. Furthermore, as mentioned above, the voids filling particles 62 can define a flow path that allows the liquid medium 64 to flow through orifices 26 and be drained through the filter medium 100. Therefore, the liquid medium 64 that has entered orifices 26 is also removed from orifices 26. As the suspension 60 continues to flow into orifices 26, particles 62 accumulate within orifices 26 until filling step 46 is completed.

[0150] Furthermore, since the support member 108 is porous relative to the liquid medium 64, the liquid medium 64 can be drawn into the vacuum chamber 90 under vacuum pressure. The vacuum pressure can be any pressure below atmospheric pressure, depending on the desired rate of the filling process. In a non-limiting example, the negative pressure can be in the range of any pressure from below atmospheric pressure to approximately 120 kPa (such as approximately 80 kPa below atmospheric pressure).

[0151] Frame 86 may define a discharge port 114 extending through frame body 87 and in fluid communication with vacuum chamber 90. Therefore, discharge port 114 may provide an outlet for liquid medium 64 to flow out of vacuum chamber 90 as a discharge of liquid medium 64. The discharged liquid medium 64 may be discarded. Alternatively, the discharged liquid medium 64 may be reused. In one example, a quantity of particles 62 may be fed into a quantity of discharged liquid medium 64 to generate a suspension 60 for use in subsequent filling operations of substrate 20, or for filling operations of different substrates 20. In one example, the discharged liquid medium 64 may be circulated as a stream through a hopper of dried particles 62, such that the hopper may release a quantity of dried particles 62 into the stream to generate a suspension.

[0152] It is understood that while the filter medium 100 may be non-porous relative to the particles 62 as described above, it should be recognized that the filter medium 100 may be porous relative to a smaller number of particles 62 than all the particles 62 entering the pores 26. Regardless of whether the filter medium 100 is non-porous relative to all or some of the particles 62, particles 62 that do not pass through the filter medium 100 may accumulate in the pores 26 in the manner described above.

[0153] Referring again to Figure 6A, it is understood that the pressure difference causes the alignment of the suspension 60, which is disposed on the outer surface 99 of the alignment 110 region, thereby aligning the suspension with the corresponding hole 26. Thus, the suspension 60 in the alignment region can be forced into the corresponding hole 26 below. Furthermore, the pressure difference pushes the suspension 60 disposed on the outer surface 99 of the substrate 20 at an offset position, which flows into the corresponding hole 26 within the influence region 112 disposed on the outer surface 99 of the substrate 20. The influence region 112 may have a circular shape on the outer surface 99 of the substrate 20, or any suitable alternative shape as required. The suspension disposed at the offset position in the influence region 112 is laterally offset from the corresponding hole 26 along a transverse direction perpendicular to the length of the hole 26. The influence region is positioned sufficiently close to the corresponding hole 26 to be drawn into the hole 26 under the force generated by the pressure difference. It has been found that the affected region 112 is substantially spherical. However, it is conceivable that the shape of the affected region 112 may also depend on several factors, including the dispersion gradient of the particles 62 in the liquid medium. It should be understood that the suspension 60 disposed on the outer surface 99 of the substrate 20 can be agitated during the filling step 46 to maintain the dispersion of the particles 62 in the liquid medium 64. For example, the substrate 20 may be vibrated, shaken, or otherwise moved to agitate the suspension 60 and cause the suspension to travel to the corresponding hole 26 or the affected region 112, thereby forcing it into the corresponding hole 26.

[0154] Depending on the amount of suspension 60 applied to the outer surface 99 of substrate 20, the amount of suspension 60 in the aligned portion and the amount of suspension 60 in the offset portion may be sufficient to fill the hole 26. Therefore, in one example, filling step 46 can be completed when substantially all of the hole 26 is filled with particles 62. Alternatively, it should be appreciated that in some examples, the amount of suspension 60 in the aligned portion and the amount of suspension 60 in the offset portion may be insufficient to fill the hole 26 in a filling operation. In this case, the vacuum pressure cannot draw additional amount of suspension 60 into the hole 26, resulting in leaving an amount of particles 62 in the hole 26 less than sufficient to fill most of the hole 26 from the first end to the second end. Therefore, it should be understood that step 46 of filling the hole 26 may include partially filling the hole 26 as well as filling substantially all of the hole 26.

[0155] Once the liquid medium 64 has been drawn into the orifice 26 from the alignment region 110 and influence 112 under vacuum pressure, and no other liquid medium 64 can be drawn into the orifice 26 under pressure differential, the continuously applied pressure differential draws air into the orifice 26. The drawn-in air forces the liquid medium 64 in the orifice to exit from the orifice 26 through a flow path defined by the gap. Because the conductive material is at least substantially non-porous, the liquid medium 64 does not enter the conductive material. Instead, the liquid medium 64 exits from the orifice 26 under pressure differential. Therefore, the pressure differential applied during the filling step results in the filling particles 62 in the orifice being at least substantially dry or completely dry relative to the liquid medium 64.

[0156] It should be understood that once the liquid medium has emptied the orifice 26, the resulting filled conductive particles 62 can come into contact with each other to define the first or initial filled powder 63 of the first filler 65. The first or initial filled powder 63 can be configured as the body portion filler as described herein. It should be recognized that when the liquid medium 64 has emptied the orifice, the surface charge of the particles 62 is no longer neutralized by the liquid medium 64, and therefore the particles 62 can aggregate with each other such that the particles 62 in the orifice 26 define the amount of filled particles.

[0157] In one example, filling step 46 may include the step of bringing additional suspension 60 into one or both of alignment region 110 and influence region 112. Additional suspension 60 may increase the amount of particles 62 filled in orifice 26. For example, additional suspension 60 may cause orifice 26 to be substantially filled along with particles 62. Alternatively, additional suspension 60 may increase the amount of particles 62 in orifice to less than the amount of particles 62 sufficient to substantially fill orifice, but greater than the amount of particles 62 filled in orifice 26 without the step of bringing additional suspension 60 into alignment region 110 and influence region 112.

[0158] For example, referring now to Figures 6A and 13A-13C, the step of bringing the additional suspension 60 into the alignment region 110 and the affected region 112 may include the step of rocking the substrate 20 to reciprocate it in one or more angled planes. Specifically, the step of bringing the additional suspension 60 into the alignment region 110 and the affected region 112 may include the step of reciprocating the rocking of the fluid pressure filling device 82 including the substrate 20. The rocking step may cause the suspension 60 on the outer surface 99 of the substrate 20 to flow across the outer surface 99. Therefore, the amount of suspension may flow into one or both of the alignment region 110 and the affected region 112 of the hole 26. When the substrate 20 is continuously rocked, the additional amount of suspension 60 may replace the amount of suspension flowing into the hole 26 from one or both of the alignment region 110 and the affected region 112. The rocker arm member 209 may be actuated to apply the rocking step. It is understood that the substrate 20 can be manually agitated by manually activating the rocker arm member. Optionally, the vacuum filling device 84 may define a rocking platform that directly or indirectly supports the substrate 20 and is configured to automatically process the substrate 20. It is understood that the fluid pressure filling device 82 may include a baffle 116 that blocks the suspension 60 and prevents the suspension 60 from flowing out of the substrate 20 when the substrate 20 is rocked. In one example, the baffle 116 may be defined by at least one gasket 94. For example, at least one gasket 94 may be defined by at least one gasket sealing the first interface 102, as described above with reference to FIG. 5. The baffle 116 may extend upward relative to the substrate 20 at a sufficient height to prevent the suspension from overflowing from the baffle 116 during the rocking step of the substrate 20.

[0159] Alternatively, referring now to FIG13D, the step of bringing the additional suspension 60 into the alignment region 110 and the influence region 112 may include the step of causing the suspension to flow across and fill the holes 26. Specifically, the suspension 60 may be applied to the outer surface 99 of the substrate 20 at a location laterally spaced from the holes 26. The substrate 20 may then be tilted, causing the suspension 60 to flow across the outer surface 99 and sequentially through the plurality of holes 26. As the suspension 60 flows through the first hole 26, a certain amount of the suspension 60 may flow into the first hole 26. The suspension 60 then flows through a second hole 26 adjacent to the first hole 26, thereby causing a certain amount of the suspension 60 to flow into the second hole 26. Thus, the tilting of the substrate 20 allows the suspension to flow into the plurality of holes 26 under the influence of gravity. In this respect, when the substrate 20 is shaken as described above with reference to FIG13A-13C, the suspension can flow into the plurality of holes 26 under the action of gravity. Alternatively, tilting the substrate 20 can allow the suspension to enter the affected area and be drawn into the holes in this area. For example, when the suspension 60 flows through a specific hole 26, the hole can be filled with the suspension 60 in the manner described above under the force applied to the suspension caused by the pressure difference. Furthermore, as described above, in FIGS. 13A-13D After the step of bringing the additional suspension 60 into the alignment region 110 and the influence region 112 is completed, the vacuum pressure applied to the orifice 26 continues to draw air into the orifice 26, thereby at least substantially drying the orifice.

[0160] As shown in Figure 3, once the liquid medium is removed from the orifice 26 during the filling step, the packing density of the particles 62 drawn into the orifice 26 in the preceding filling step 46 can be increased in the compaction step 50. Therefore, the step of compacting the particles 26 in the orifice can be performed. Referring now to Figures 8A-8B, in one example, the substrate 20 can be placed in a sleeve 118. The sleeve 118 includes a first laminate 119a and a second laminate 119b spaced apart from the first laminate 119a to define and configure an internal space 124 for receiving the substrate 20.

[0161] Specifically, the first laminator 119a may include a first outer sheet 120a and a first inner layer 122a. The second laminator 119b may include a second outer sheet 120b and a second inner layer 122b. The first inner layer 122a and the second inner layer 122b face each other and thus face the substrate 20 when the substrate 20 is arranged in the internal space. As will be understood from the following description, the first and second inner layers 122a and 122b may be referred to as the first and second compaction members, respectively, which are configured to apply pressure to the dry, initially filled powder 63, which further compresses the dry, initially filled powder 63 into a highly filled powder 77, the particles 62 of which are more compressed together after the filling and defilling step 46 and before the compaction step 50. In particular, the first inner layer 122a and the second inner layer 122b may be sufficiently flexible to extend into the corresponding holes 26 to compress the particles 62. In this respect, the envelope 118 may be referred to as a soft-pack enclosure. Similarly, compaction step 50 can be referred to as a soft compaction step. It should be understood that the density of particles 62 in the holes 26 after compaction step 50 can be greater than the density after filling step 46 and before compaction step 50; in this respect, compaction step 50 can also be referred to as a densification step.

[0162] The internal space 124 is sized and configured to receive the substrate 20 after the step of removing the liquid medium 64 from the hole 26. Therefore, the inner layer 122 faces the corresponding opposing surface of the substrate 20. The outer sheet 120 is airtight and can surround the inner layer 122. Therefore, when the first lamination 119a and the second lamination 119b are fused together such that the internal space 124 is completely surrounded to define the outer shell 126, air cannot enter the outer shell 126.

[0163] In one example, corresponding portions of the first laminate 119a and the second laminate 119b can be sealed to each other to partially define the housing 126. The substrate 20 can then be placed in the interior space 124 prior to forming the housing 126, such that the inner surface 97 faces one of the first inner layer 122a and the second inner layer 122b, and the outer surface 99 faces the other of the first and second inner layers 122a and 122b. Subsequently, a vacuum is applied to the interior space 124 of the housing 126 to remove air from the interior space 124, and the first and second laminates 119a and 119b can be sealed, for example, by heat sealing, to define the housing 126 under vacuum. When the housing 118 is placed under vacuum, the inner layers 122a and 122b can lie flat and abut against one of the inner surface 97 and the outer surface 99 of the substrate 20, and can extend over the aperture 26. Furthermore, the first inner layer 122a and the second inner layer 122b can abut against any overfilled particles 62 that are filled in more than one or both of surfaces 97 and 99.

[0164] Therefore, referring now to Figure 8C, the envelope 118 can be placed in a press 128 configured to apply sufficient external pressure to the envelope 118 to densify the particles 62 of the initially filled powder 632. For example, the press 128 can be an isostatic press that applies isostatic pressure to the laminate. Therefore, the compaction step 50 can be referred to as an isostatic pressing step. Isostatic pressure can be applied to the outer sheets 120a and 122a, which in turn apply isostatic pressure to the inner layers 122a and 122b. The isostatic pressure can range from about 5000 pounds per square inch (PSI) to about 60000 PSI. For example, the isostatic pressure can range from about 20000 PSI to about 50000 PSI. In one instance, isostatic pressure can range from approximately 25,000 PSI to approximately 40,000 PSI.

[0165] The pressure applied to the isostatic press of the sleeve 118 can drive the inner layers 122a and 122b into the opposite ends of the orifice 26 under isostatic pressure, thereby further compacting the particles 62 of the initially filled powder 63 achieved in the filling step 46 into a high-density filled powder 77, whose particles 62 are more tightly packed than the filling particles 62. Therefore, it can be said that the pressure densifies the particles 62 in the orifice 26. Specifically, the isostatic pressure driving the inner layers 122a and 122b to densify the filling powder 63 means that, as the initially filled powder is further filled into the high-density powder, the distance along the length of the orifice 26 decreases relative to the distance occupied by the particles of the initially filled powder. That is, the particles 62 can be longitudinally compressed within the orifice 26.

[0166] Isostatic pressing can be applied at room temperature. In this respect, the isostatic press can be referred to as a cold isostatic press (CIP). Alternatively, the isostatic press can be configured as a warm isostatic press (WIP), which can be configured to apply isostatic pressing at a temperature of approximately 120 °C to approximately 250 °C for a period of time sufficient to deform and further densify the particles 62. That is, the substrate 20 and the conductive particles 62 can be heated during the compaction step. The compaction step under WIP can displace the aforementioned anti-caking agent to promote metal-to-metal contact between adjacent particles 62 in the body portion filling and adjacent particles 62 in the port filling when the body portion filling and port filling are compacted.

[0167] Without being bound by theory, it is believed that the inner layers 122a and 122b can densify the outer ends of the initially filled powder 63 more than the middle portion of the initially filled powder 63 extending between the outer ends. Furthermore, referring also to FIG. 6B, the inner layers 122a and 122b can drive the initially filled powder 63 of the first filling step 46 to move towards the center of the hole 26 within the hole 26, thus the initially filled powder 63 can be driven relative to the total length of the hole 26 to substantially the center of the hole 26, as shown in FIG. 6B. The subsequent filling compaction step can drive the resulting subsequent filled powder 79 against the powder drawn into the hole 26 during the previous filling step 46, i.e., the previous powder. The previous powder can be defined by one or both of the first filling steps 46, and, if desired, by one or both of the subsequent filling steps 46, and, if desired, by the subsequent compaction step 50.

[0168] In one example, as the inner layers 122a and 122b extend into the opposite ends of the hole 26, the inner layers 122a and 122b can apply substantially equal amounts of pressure to each end of the hole 26. Therefore, the initially filled powder 63, offset from the center relative to the length of the hole 26, can contact and be driven to the center of the hole 26 in one of the inner layers 122a and 122b, and pressed between the inner layers 122a and 122b. The initially filled powder is then pressed against the previously compressed high-fill powder. Thus, one of the inner layers 122a and 122b contacts the outer end of the previously compressed high-fill powder, and the other of the inner layers 122a and 122b contacts the outer end of the subsequently initially filled powder, thereby highly compacting the subsequently initially filled powder into a high-fill powder. When the initially filled powder is longitudinally filled by the inner layers 122a and 122b, it should be understood that the initially filled powder may expand radially as it is filled into the high-fill powder, thereby pressing the corresponding particles 62 against the inner wall of the fixed hole 26 of the substrate 20.

[0169] The inner layers 122a and 122b can be made of any suitable material as needed. In one example, the inner layers 122a and 122b can be made of a viscoelastic material and are therefore configured to enter the hole 26 to compress the particles 62 disposed therein. For example, the inner layers 122a and 122b can be uniformly distributed with the isostatic pressure applied to the substrate, such that the inner layers 122a and 122b conform to the outer surfaces 22 and 24 of the substrate 20 and extend into the hole 26. Thus, the inner layers 122a and 122b can mechanically fill the initially filled powder 63 into a highly filled powder. Therefore, it is desirable that the inner layers 122a and 122b be made of a material that does not adhere to the particles 62, such that when the isostatic pressure is removed, the inner layers 122a and 122b can be removed from the hole 26 without pulling the particles 62 out of the hole 26. In one example, the inner layers 122a and 122b can be made of polyester film (Mylar). In another example, the inner layers 122a and 122b can be made of polytetrafluoroethylene (PTFE). The outer sheets 120a and 120b can be made of any suitable non-porous material. For example, the outer sheets 120a and 120b can be made of a flexible metal such as aluminum.

[0170] In one example, if desired, the outer sheets 120a and 120b may include a molten material 121, for example, a mylar polyester film coated onto their respective inner surfaces. The molten material 121 may self-melt to form a vacuum shell 126. The inner layers 122a and 122b may be separable from the outer sheets 120a and 120b and placed between the outer sheets and the substrate 20, or, if desired, the inner layers 122a and 122b may cover the inner surfaces of the outer sheets 120a and 120b.

[0171] Therefore, it should be understood that the vacuum in the housing 126 is sufficient to allow the inner layers 122a and 122b to lie flat on the inner surface 97 and outer surface 99, either alone or in combination with overfill. Thus, it will be appreciated that any suitable means for allowing the inner layers 122a and 122b to lie flat on the inner surface 97 and outer surface 99, either alone or in combination with overfill, can be contemplated before applying isouniform hydrostatic pressure directly or indirectly to them. Therefore, the inner layer can be referred to as a compaction member, which is configured to be driven into the hole 26 of the substrate 20 to highly fill the initially filled powder 63 as a highly filled powder disposed therein.

[0172] Now for reference FIG. 3 As shown in Figure 6B, the step of increasing the fill density 50 is completed once the isostatic pressing has been removed from the compaction member. Once the step of increasing the fill density is completed, the first filling and compaction sequence 55 is also completed. However, it should be understood that in some examples, step 50 may be omitted. Instead, as described in more detail below, the step of pressing the substrate 20 to encapsulate the particles 62 may be performed at step 53. Furthermore, in other examples, both steps 50 and 53 may be performed during method 40. Further, it should be understood that in step 46, the step of isostatically pressing the particles 62 may be performed separately between multiple instances between multiple sequential iterations.

[0173] Referring to Figures 6B through 7C, it will be recognized that in some examples, the particle 62, following the first filling step 46 and optionally the first compaction step 50, can define a body portion fill extending only a portion of the hole 26. In other examples, the body portion fill can extend along most of the hole 26. When the body portion fill extends only a portion of the hole, the particle 62 can occupy a length of the hole 26 less than the entire length of the hole 26, thereby defining a longitudinal distance measured from each of the first surface 22 and the second surface 24 of the substrate 20 for the body portion fill. If each of these distances is greater than a predetermined distance, a subsequent sequence 55 is performed to fill the hole 26 with additional body portion fill until the distance reaches the predetermined distance. If each of these distances is less than or equal to the predetermined distance, a port fill can be introduced between the body portion fill and the first and second ends of the hole 26. The distance can be determined after performing the filling step 46. Alternatively, the distance can be determined after performing compaction step 50, which compacts the port filler and further presses the port filler against the main body filler that may have been compacted during the previous compaction step.

[0174] Alternatively, it can be appreciated that in some examples, the particles 62 of the body portion filler may extend from the first end of the hole 26 to the second end of the hole after the first compaction step 50. Thus, the body portion filler may extend substantially from the first surface 22 of the substrate 20 to the second surface 24 of the substrate 20. For example, the body portion filler may extend from the hole 26 beyond one or both of the first surface 22 and the second surface 24 of the substrate 20, so that a single filling step 46 may fill the hole 26 such that the conductive particles 62 continuously extend through the hole and may extend from the hole 26 beyond each of the first surface 22 and the second surface 24 of the substrate 20. As will be understood from the description below, the particles 62 may then be compacted within the hole 26 and abut against one or both of the first surface 22 and the second surface 24 during the pressing step 53, which is described in more detail below.

[0175] In one example, the predetermined distance can range from approximately 1 micrometer to approximately 30 micrometers. In another example, the range can be from approximately 1 micrometer to approximately 20 micrometers. For example, the range can be from approximately 1 micrometer to approximately 10 micrometers. For example, the range can be from approximately 2 micrometers to approximately 6 micrometers. In one example, the predetermined distance can range from approximately 0.5% to 25% of the total length of the aperture 26. For example, the range can be from approximately 0.5% to approximately 20% of the total length of the aperture 26. For example, the range can be from approximately 0.5% to approximately 15% of the total length of the aperture 26. For example, the range can be from approximately 0.5% to 10% of the total length of the aperture 26. For example, the range can be from approximately 0.5% to approximately 5% of the total length of the aperture 26. For example, the range can be from approximately 1% to approximately 4% of the total length of the aperture 26.

[0176] When the distance reaches a predetermined size or size range, at least one final sequence 55 of filling and pressing steps can be performed. Therefore, the particles 62 entering the hole 26 during the port filling step 46 of the final sequence 55 can be referred to as port filling as shown in FIG. 9B. The port filling is intended to occupy a portion of the hole 26 extending from the body portion filler to the first and second end portions of the hole 26. When the hole 26 is a through hole, the port filling is intended to extend from the body portion filler to each of the first surface 22 and the second surface 24 of the substrate 20, and the particles 62 of the body portion filler can be defined by a first particle 62a, which is constructed and intended to extend along a substantial length of the hole 26. The particles 62 of the port filling can be defined by a second particle 62b, but it should be understood that particles of other sizes are conceivable for port filling. Thus, in one example, the hole 26 can be filled with both the body portion filler and the port filling.

[0177] As shown in Figure 9A, when each distance is greater than a predetermined distance, the subsequent filling step 46 is performed in the manner described above, so as to generate initially filled powder 63 from the subsequent filling 67 of the subsequent filling step 46. The subsequent filling step 46 may be a body portion filling step. As shown in Figure 9B, the subsequent compaction step 50 can generate highly filled powder 77 from the subsequent filling 67. More highly filled powder can be filled than after the first filling step, and optionally after the first compaction step 50. Therefore, as described above with reference to the first filling step, the subsequent filling step begins at step 46, thereby performing the subsequent filling step 46 in the manner described above with respect to the first filling step, as shown in Figure 9A. In particular, the inner surface 97 of the substrate 20 is placed against the filter medium 100 in the manner described above.

[0178] Reference FIG. 9A The highly packed powder 77 of the first filler 65 provides an embolus 95 that allows the gaseous, i.e., liquid medium 64 to pass through, but not the first particle 62a. Specifically, when the particle 62 in the orifice 26 defines the aforementioned unimodal distribution, the particle 62 defines a void 66. Alternatively, when the particle 62 of the first filler 65 defines a bimodal distribution 72, the particle 62 can define first and second bimodal voids 66 and 75, respectively, as described above. Furthermore, when the particle 62 of the first filler 65 defines a trimodal distribution 73, the particle can define first, second, and third trimodal voids 66, 75, and 69, respectively, as described above. For example, the size of the voids in the first filler 65 can be smaller than the first particle 62a. Therefore, it can be said that the embolus 95 defines an internal filter in the orifice 26 that is non-porous for the first particle 62a. The embolus 95 can be defined by the highly packed powder 77, or by the first particle 62a drawn into the orifice 26 during the first filling step 46. The pores of the internal filter are large enough to be porous relative to both fluid and air. Therefore, it is anticipated that particles 62 flowing into the orifice 26 in the subsequent filling step 46 will be prevented by the internal filter, defined by the first particle 62a, from passing through the orifice 26 and reaching the filter medium 100 located below the substrate 20. However, it is still desirable to include the filter medium 100 as a barrier to protect the support member 108 (see...). FIG. 5 This protects the filter media 100 from stray particles that may flow through the orifice 26. In some examples, the filter media 100 in the subsequent compaction step may have a coarser particle size than the filter media 100 in the first compaction step.

[0179] Referring now to FIG9A, during the first subsequent fill step 46, the inner surface 97 of the substrate may be defined by the same one of the first and second surfaces 22 and 24, which define the inner surface 97 during the immediately preceding fill step, which may be the first fill step as shown, or alternatively a subsequent fill step. Similarly, the outer surface 99 may be defined by the same one of the first surface 22 and the second surface 24 that define the outer surface 99 during the immediately preceding fill step. Alternatively, the substrate 20 may be flipped relative to the immediately preceding fill step such that the inner surface 97 is defined by the other of the first surface 22 and the second surface 24. Similarly, the substrate 20 may be flipped relative to the immediately preceding fill step such that the outer surface 99 is defined by the other of the first surface 22 and the second surface 24.

[0180] Therefore, during the first subsequent filling step, vacuum pressure can cause the suspension 60 to flow into the same one of the first and second ends of the hole 26 as in the immediate preceding filling step. Alternatively, the substrate 20 can be flipped so that vacuum pressure causes the suspension 60 to flow into the opposite end of the first and second ends of the hole 26.

[0181] As shown in Figure 9A, a first subsequent filling step 46 can be performed such that the subsequently filled powder 79 of the subsequent filling 67 of the first subsequent filling step 46 fills the hole 26. That is, the particles 62 of the subsequently filled powder 79 fill outside one of the first surface 22 and the second surface 24. However, it should be recognized that the subsequent compaction step 50, if performed, compacts the subsequently filled powder 79 into a subsequently high-fill powder. Therefore, after the subsequent filling step 46 but before the subsequent compaction step 50, the distance along the length of the hole 26 occupied by the subsequently high-fill powder is reduced relative to the distance occupied by the particles 62 of the subsequently filled powder 79. That is, if performed, the particles 62 can be longitudinally compressed during the subsequent compaction step 50. Therefore, even before compaction, if the particles 62 are overfilled (meaning they extend beyond one or both of the first surface 22 and the second surface 24), the subsequent height of the filled powder, defined by the subsequent filling 67 after the compaction step 50, can be recessed relative to the corresponding outer surface of the substrate 20, as shown in FIG9 B, thereby defining the aforementioned distance.

[0182] Once the first subsequent filling step 46 has been performed at one end of the hole 26 as shown in FIG. 9A to define the subsequent filling powder 79, subsequent filling powder 67 can then be filled into the highly filled powder 77 as shown in FIG. 9B in step 50, as desired. Thus, the conductive material may comprise regions of highly filled powder 77 spaced apart from each other along the hole and along the resulting via. Alternatively, the compaction step 50 may be omitted, such that particles 62 extending at least to (and potentially through) one end of the hole 26 can remain as the subsequently filled powder 79 without being highly filled. Next, as shown in FIG. 9B, the substrate 20 may be flipped relative to FIG. 9A. A second or opposite subsequent filling step 46 may be performed at the opposite ends of the hole 26 to define a second or opposite subsequent filling powder 81 that extends to and potentially through the opposite ends of the hole 26. Next, if necessary, a relative subsequent compaction step 50 can be performed to compact the relatively subsequently filled powder 81 into a highly filled powder 77, if desired. Therefore, the first or initial filled powder 63 of the first filler 65 can be positioned between the subsequently filled powder 79 and the relatively subsequently filled powder 81. Any one or more, or even all, of the first or initial filled powder 63, the subsequent filled powder 79, and the relatively subsequently filled powder 81 can define a highly filled powder 77, if desired. FIG. 9C As shown, the particles 62 of the first filler 65 and the subsequent filler 67 can be combined to define the main body filler 130.

[0183] Referring now to Figures 9C and 12A, when the aforementioned distance is within a predetermined distance, a port filling step 46 can be performed at each end of the hole 26. That is, a first port filling step 46 can be performed at the first end of the hole 26, such that the particles 62b of the second suspension extend from the main body filler to the first surface 22, and in some cases, exceed the first surface 22. Subsequently, as described in more detail below, the substrate 20 can be flipped to perform a second port filling step, whereby the particles 62b of the second suspension extend from the main body filler to the second surface 24, and in some cases, exceed the second surface 24.

[0184] At least one port filling step 46 may be included, comprising a first port filling step and a second port filling step, so a second suspension 60b may be used as needed. The particles 62b of the second suspension 60b may define the port filler. Optionally, the first suspension 60a may be used for the port filling step 46; therefore, although the port filling step 46 is described below in conjunction with the second suspension 60b, this description is equally applicable to the final filling step 46 of the first suspension 60a. The final filling step 46 may be performed after the first filling step 46 or after one or more subsequent filling steps 46, or the port filling step 46 may be omitted if the first filling step 46 causes the particles 62 to extend beyond the first surface 22 and the second surface 24 of the substrate 20 and the compaction step 50 is omitted.

[0185] The suspension 60 used during the port filling step can be defined by a second suspension 60b or any suitable alternative suspension as needed to produce the port-filling powder 132. During the first port filling step 46, a first final suspension 60 can be filled at one end of the hole 26 to define the first port fill. Vacuum force can be used to evacuate the liquid from the suspension 60 in the manner described above. During the second or opposite port filling step 46, a second or opposite suspension 60 can be filled at the opposite end of the hole 26 to define the second port filler, whereby vacuum force can evacuate the liquid from the suspension 60. The particles 62 of the port filler can be defined by the second suspension 60b, or alternatively, by the first suspension 60a as described above. The first port filler can be overfilled in the hole 26 to extend beyond the outer surface 99 of the substrate 20, which can be defined by a first outer surface 22 or a second outer surface 24. Then, if necessary, a first final compaction step 50 can be applied to the first port filler to compact the port-filled powder 132 into a height-filled powder 77 of the port filler 134, as shown in FIG12B. In this regard, it should be understood that the height-filled powder 77 of the port filler 134 may be overfilled relative to the hole 26 before and after the compaction step.

[0186] Next, substrate 20 can be flipped, and a second or opposite port filling step can be performed to fill the opposite ends of the holes with a second final suspension to produce opposite port filling powder or a second port fill at the opposite ends of the holes 26. The second final suspension can be filled in step 50 to produce a highly filled powder of port fill 134 as shown in FIG. 12B, substantially flush with and / or substantially flush with the first surface 22 and the second surface 24. In the context of planarity and flush with the first surface 22 and the second surface 24, the term “substantially” means that minor variations may exist in perfect planarity and perfect flush, but for future patterning and subsequent use purposes, those skilled in the art will understand that it means flush. Optionally, as described above, compaction step 50 can be omitted. Optionally, if the first port filler is not filled at the compaction step 50, the compaction step 50 can be performed after the second or opposite port filler step 46 to produce a highly filled powder from the port filler powder of the first and second port filler steps 46. The last filled relative filler powder 77 can also be overfilled in the hole 26 after the port filler step 46, and further after the desired compaction step.

[0187] It can be recognized that, regardless of whether filling occurs at step 50, the compacted body portion filler 130 and the compacted port filler 134 can be combined to define the filler 35 of the guide hole 34, and thus the filler 35 can be referred to as being defined by a conductive material.

[0188] Once the final compaction step has been performed, excess particles can be removed from the substrate 20. In this regard, the first port filler extends from the body portion filler to the first surface 22 of the substrate 20 and can be overfilled such that excess first port filler extends beyond the first surface 22. Optionally or additionally, the second port filler extends from the body portion filler to the second surface 22 of the substrate 20 and can be overfilled such that excess second port filler extends beyond the second surface 24. Therefore, one or both of the excess first and second port fillers can be removed after the final compaction step and before sintering the particles to substantially flush the first and second port fillers. For example, a rod can be driven onto the first surface 22 of the substrate 20 to remove excess first port filler and across the second surface 24 of the substrate to remove excess second port filler. The rod can have a hardness greater than that of the port filler and less than that of the substrate 20. In one example, the rod can be a rubber rod. In another example, the rod can be a Teflon rod. Next, the particles 62 in the hole 26 can be substantially non-densely sintered to create a conductive via 34, as described in more detail below.

[0189] It should be recognized that, if applicable, the density of particles 62 in the pores 26 of the first filler 65 is greater than the density of particles 62 in the pores of the initial filling powder 63 of the first filler 65. It is further recognized that, if applicable, the density of particles 62 in the pores 26 of the subsequently filled powder 77 is greater than the density of particles 62 in the pores of the subsequently filled powder 63. Similarly, it should be recognized that, if applicable, the density of particles 62 in the pores 26 of the highly filled powder 77 of the port filler 134 is greater than the density of particles 62 in the pores of the port filling powder 132.

[0190] Referring now to FIG10, it can be recognized that the subsequent filling step 46 can be performed by subsequently filling one side of the hole with particles 62, flipping the substrate 20, and then filling the opposite side of the hole with particles in step 50 after the first subsequent filling step 46, and then, in the case of execution, the compaction step 50 can simultaneously fill both ends of the hole 26 with the first and second subsequently filled particles 62.

[0191] In this respect, the vacuum device 84 can define a suspended vacuum device 85. Specifically, the suspended vacuum device can be constructed as described above with reference to FIG5 for the vacuum device 84. However, the gasket 94 of the suspended vacuum device 85 can extend through the interface between the shelf 96 and the support member 108. The gasket 94 can be spaced apart from the outer surface of the support member 108. Therefore, the substrate 20 can be placed on the outer surface of the gasket 94, and thus the alignment area of ​​the substrate 20 defining the hole 26 can be suspended above the support member 108. Therefore, an air gap 136 can be defined between the substrate 20 and the support member 108. Specifically, the substrate 20 and the support member 108 can be spaced apart from each other in the same direction as the extension of the hole 26.

[0192] Gap 136 is sufficient to accommodate overfilling of powder particles 62 generated during port filling step 46, such that overfilling facing support structure 108 does not contact support structure 108. As described above, when the liquid medium 64 in the orifice is evacuated, the remaining particles 62 can be referred to as dry-filled powder. Furthermore, because the surface charge of particles 62 is no longer neutralized by the liquid medium 64, particles 62 can agglomerate with each other. Therefore, the agglomerated particles will not fall out of orifice 26 and into gap 136 before being packaged into highly filled powder. If necessary, filter medium 100 can be placed above support member 108 to protect support member 108 from any stray particles 62 escaping through orifice 26 during filling step 46. Filter medium 100 can extend across support member 108 and into the interface between gasket 94 and support member 108 as needed.

[0193] During operation, referring to FIG11, at least one gasket seals the first interface 102 between the substrate 20 and the support member 108, or alternatively seals the airflow between the substrate 20 and the filter medium. At least one gasket may further seal the second interface between the support member 108 and the shelf 96 relative to the airflow therebetween. A gasket 94 may support the periphery of the substrate 20 at the aforementioned exclusion area. Furthermore, portions of the gasket 94 or other auxiliary support members may extend between the support member 108 and the substrate 20 to support a central region of the substrate 20 that may be subjected to increased forces from the applied negative pressure.

[0194] The suspension 60 is applied to the outer surface 99 of the substrate 20 until the corresponding additive in the hole 26 is filled with particles as described above. Liquid medium 64 is drained from the hole 26 in the manner described above. Next, the substrate is flipped so that the previously inner surface 97 now defines the outer surface 99, and the suspension is applied again to the outer surface 99, and the corresponding hole is filled with particles. If the subsequent filling process is a body portion filling process, the first and the opposite subsequent filling powders can be filled without performing the compaction step 50 between the steps of filling the first subsequently filled powder and filling the opposite subsequently filled powder. Next, if necessary, the substrate 20 can be encapsulated in step 50 as described above. The compaction step 50 can cause both the first subsequently filled powder and the opposite subsequently filled powder to be filled into the corresponding height-filled powder. Alternatively, the compaction step 50 of the subsequent filling process can be omitted. Alternatively, if the subsequent filling process is a port filling process, the first and the opposite last filling powder 132 can be filled without performing the compaction step 50 between the steps of filling the first port filling powder and filling the opposite last powder. After the final filling step 46, the substrate 20 can be packaged in step 50 above, so that both the powder filling the first port and the powder filling the opposite port are filled into the corresponding high-fill powder 77, as shown in Figure 12A.

[0195] Therefore, it can be recognized that the suspended vacuum device 85 can be used to fill the holes 26 with first and second or opposite subsequently filled powders before compacting the particles 62 in step 50. If compaction step 50 is performed, the first and opposite subsequently filled powders can be simultaneously filled into a highly filled powder. Alternatively, as described above, compaction step 50 can be omitted. Alternatively or additionally, the suspended vacuum device 85 can be used to fill the holes 26 with first and opposite last filled powders before performing the final compaction step 50. The final compaction step 50 can simultaneously package both the first and opposite last filled powders into a highly filled powder. Optionally, as described above, the final compaction step 50 can be omitted.

[0196] Alternatively, referring to Figure 12C, the compaction step 50 can be omitted after the final filling step 46 is completed. When the compaction step 50 is omitted from method 40, the particles 62 in the holes 26 can extend substantially from the first surface 22 to the second surface 24. In some examples, after one or more filling steps 46 have been completed, the particles 62 can extend beyond the first surface 22 and the second surface 24. Furthermore, after one or more filling steps are completed, and when the sintering step 52 (see Figure 3) is to be performed, the particles 62 in the holes 26 may not have areas of highly filled powder 77.

[0197] Referring now to Figure 19A, although the filling step 46 has been described as inducing air pressure in the example described above to drive the suspension 60 into the orifice, it should be recognized that the filling step 46 can be performed according to several other examples. For example, the centrifuge 150 can provide a force to drive or pull the suspension 60 into the orifice 26. In one example, the orifice 26 can be a through hole of the type described above. Therefore, the force causing the particles 62 to flow into the orifice 26 can be a centrifugal force. The centrifuge 150 can include a rotatable hub 152, at least one hopper 156 (such as a plurality of hoppers 156), and an arm 154 extending between the hub 152 and the hoppers 156.

[0198] As shown in Figure 19B, substrate 20 can be placed in hopper 156 such that substrate 20 is supported by the distal sidewall 158 of hopper 156. Therefore, the inner surface 97 of substrate 20 faces the distal sidewall 158 of hopper 156, and the outer surface 99 of substrate 20 faces away from the distal sidewall 158. The inner surface 97 can be defined by one of a first surface 22 and a second surface 24. The outer surface 99 can be defined by the other of the first surface 22 and the second surface 24. The inner surface 97 can be placed against a corresponding support surface 157 of the distal sidewall 158 within hopper 156. The support surface 157 of hopper 156 can be planar and made of a suitable material that will allow substrate 20 to be subsequently removed from the inner surface 157 without causing the pull-out of particles disposed in the holes. Optionally, an auxiliary support member 160 may be placed in a hopper 156 between the substrate 20 and the inner surface 157. The support member 160 may define a support surface such that the inner surface 97 of the substrate 20 rests against the support surface. The support member 160 may be made of any suitable material, such as glass, which may be coated as needed to prevent the support member 160 from adhering to the particles on the substrate 20. The inner surface 157 or the support member 160 may seal the inner surface 97 of the substrate 20 to prevent particles 62 from exiting the hole 26 at the interface between the inner surface 97 of the substrate 20 and the support surface. In some examples, it should be appreciated that the hole may be a blind hole, different from a through hole. Thus, the centrifuge 150 may allow particles to flow into the blind hole through the open end, thereby filling the blind hole in a manner described herein as relating to filling through holes.

[0199] As shown in Figure 19B, the suspension 60 can then be applied to the outer surface 99 of the substrate 20 in the hopper 156, such that the suspension covers at least a portion of the outer surface 99. As described above, the suspension 60 can be ultrasonically treated or otherwise agitated to disperse the particles 62 in the liquid medium 64 before the suspension is applied to the substrate 20 in the hopper 156.

[0200] The hopper 156 can be oriented in a first direction such that the inner surface 157 can be oriented substantially horizontally, preventing the suspension 60 from slipping off the outer surface of the substrate or otherwise spilling out of the hopper. Next, referring to FIG19C, the hopper 156 is pivotally attached to the arm 154, so that as the hopper 156 rotates about the hub 152, the hopper 156 can pivot from a first orientation to a second orientation, whereby the inner surface 157 is oriented substantially vertically or substantially perpendicular to the first orientation. The centrifuge 150 can rotate the hopper 156 about the hub 152 at any suitable speed as needed. For example, the centrifuge 150 can rotate at any suitable G-force applied as needed to drive the particles 62 into the orifice 26. For example, the G-force can be between approximately 100 and approximately 15,000 Gs. In one example, the G-force can be approximately 6,000 Gs.

[0201] As shown in Figure 19D, it should be recognized that the specific gravity of particles 62 is significantly higher than that of the liquid medium 64. Therefore, the centrifugal force applied to the suspension 60 causes the particles 62 to displace the liquid medium 64 from the hole 26 and flow into the hole 26. The particles 62 in the hole 26 abut against each other under the action of centrifugal force, thereby generating filler powder 162. However, because the liquid medium 64 is retained in the gaps between the particles of the filler powder 162, the filler powder 162 can be referred to as wet filler powder. After the centrifugation operation is completed, the volume of residual liquid medium 64 may be retained on the outer surface 99 of the substrate 20. As shown in Figure 19D, the solid content of the suspension 60 may be greater than the volume of solids filling the hole 26, such that the residual liquid medium 64 may include a certain amount of particles 62. However, the concentration of particles 62 in the residual liquid medium 64 outside the substrate 20 after the filling operation is less than the particle concentration of the suspension 60 before the operation of the centrifuge 150. Alternatively, the particle content of suspension 60 can be calculated to fill orifice 26 during centrifugation, such that substantially no particles 62 remain in residual liquid medium 64. Once orifice 26 has been filled with filler powder 162, centrifugation is stopped, and residual liquid medium can be dried from substrate 20 or otherwise removed from substrate 20.

[0202] The liquid medium 64 in the orifice 26 can then be removed. For example, the substrate 20 can then be placed in any suitable warm environment to allow the liquid medium to evaporate. Optionally or additionally, air can be forced through the orifice 26 to remove the liquid medium from the orifice 26. It should be understood that, in one example, when the filling process is performed using a centrifuge 150, the filling process 46 can be brushless. That is, method 40 can omit any step of brushing or otherwise carrying any structure along the outer surface of the substrate 20 to forcibly remove excess conductive material from the outer surface 99 of the substrate 20 after the filling step 46. Alternatively or additionally, referring to FIG19E, the step of removing residual liquid 64 from the outer surface 99 of the substrate 20 can be performed before or after the liquid medium 64 has been removed from the orifice 26. For example, any suitable rod 103 can be driven on the outer surface 99 of the substrate 20 to remove residual liquid 64 containing particles 62. The rod 103 can be made of any material that does not pull the conductive particles out of the orifice 26, as needed. For example, Teflon or nickel rods may be particularly suitable. Alternatively, if the remaining liquid medium 64 does not contain particles 62, the residual liquid medium 64 can be removed in the manner described above without using rod 103.

[0203] After performing filling step 46 using a centrifuge, compaction step 50 can be performed. In one example, compaction step 50 can be performed after removing residual liquid medium 64 and particles 62 from the outer surface 99 of substrate 20. Specifically, substrate 20 can be placed inside envelope 118, as described above. FIGS. 8A-8B The method described above removes air from the sleeve 118 and presses the substrate 20 into the press 128, as described above with reference to FIG8C. The compaction step 50 can further compact the particles 62 into the holes 26, thereby forming the main body filler of the dry, highly filled powder as described above.

[0204] Alternatively, compaction step 5 can be performed without first removing the residual liquid medium and particles 62 from the outer surface 99. Without being bound by theory, it is believed that if the residual liquid medium 64 and particles 62 are not removed first, most or substantially all of the remaining liquid medium 64 and particles 62 can be removed from the substrate by adhering to the inner layers 122a and 122b during removal from the outer shell after compaction step 50 is completed. Alternatively, as described above, compaction step 50 can be omitted after filling step 46 has been performed using a centrifuge.

[0205] In one example, after the filling step 46 using a centrifuge, it is recognized that at least one filler of the obtained particles 62 can extend along the entire length of the hole 26 from a first end of the hole to a second end of the hole 26. In one example, the body portion filler of particles 62a can extend along the entire length of the hole 26. Optionally, the first filling step 46 under centrifugal force can introduce a plurality of second particles 62b into the hole 26 to define a port filler entering the hole 26 from the outer surface 99. Thus, this step introduces a first port filler into the hole 26. Centrifugal force causes the particles to flow to the inner surface 97 and accumulate in the hole 26 toward the outer surface 99. Thus, the first port filler extends to the inner surface 97, which can be defined by the first surface 22 of the substrate 20. Next, the second filling step 46 under centrifugal force can introduce a plurality of first particles 62a from the outer surface into the hole 26 to define a body portion filler extending from the first port filler toward the second surface 24. Therefore, this step introduces the main body portion filler into the hole 26. A gap can be defined from the main body portion filler into the hole on the outer surface 99, which can be defined by the second surface 24 of the substrate 20. Therefore, after the second filling step, a third filling step under centrifugal force can introduce a plurality of second particles 62b into the hole as second port fillers. Therefore, the step introduces the second port fillers into the hole 26. The second port fillers can extend from the main body portion filler to the second surface 24. It is understood that the compaction step 50 can be applied to the particles in the hole 26 after the first filling step and before the second filling step. Alternatively or additionally, the compaction step 50 can be applied to the particles in the hole after the second filling step and before the third filling step. Optionally, a single filling step that substantially fills the hole with the second particles 62b can be performed.

[0206] In some examples, the first filling step may include introducing first particles 62a of the body portion filler into the aperture using a gas pressure differential of the type described above. Then, first and second port fillers may be introduced into the aperture under centrifugal force. For example, the first port filling step under centrifugal force may force the first particles 62a into the aperture such that they extend substantially from the bulk filler to a first surface of the substrate. The second port filling step under centrifugal force may force the first particles 62a into the aperture such that they extend from the body portion filler to a second surface of the substrate, for example, when the body portion filler in the aperture has been presented as substantially non-porous and therefore not suitable for gas pressure differential filling. As will be described in more detail below, one or more metals may be deposited into the voids of the body portion filler, which may reduce the porosity of the body portion filler.

[0207] The compaction step 50 extends the gap from the first particle 62a to the second surface 24. Optionally, the amount of the first particle 62a introduced into the hole can be predetermined to be less than the amount of the hole 26 not occupied by particles. Therefore, the second filling step can define the gap before or without performing the compaction step 50. Optionally or additionally, the compaction step 50 can be applied to the particles in the hole after the third filling step. The resulting hole includes a main portion filler in the hole, a first port filler extending from the main portion filler to the first surface 22 of the substrate 20, and a second port filler extending from the main portion filler to the second surface 24 of the substrate 20.

[0208] If necessary, the substrate 20 may be vibrated during the step of introducing at least one filler into the hole 26. For example, the substrate 20 may be vibrated during the application of centrifugal force in the first filling step to induce the second particle 62b into the hole 26. Optionally or additionally, the substrate 20 may be vibrated during the application of centrifugal force in the second filling step to induce the first particle 62a into the hole 26. Alternatively, the substrate 20 may be vibrated during the application of centrifugal force in the third filling step to induce the second particle 62b into the hole 26.

[0209] Furthermore, particles 62 may extend beyond one or both of the first surface 22 and the second surface 24 of the substrate 20. For example, before performing the filling step 46 under centrifugal force, the inner surface 97 of the support member 160 and one or both of the surfaces facing the inner surface 97 may be pre-coated with suspension 60, thereby creating overfill at the inner surface 97. The pre-coated suspension 60 may include second particles 62b. Thus, the first port filler including the second particles 62b can be overfilled in the hole 26 and can therefore extend relative to the inner surface 97 or the first surface 22. Alternatively, before performing the filling step 46 under centrifugal force, a support member may be provided between the support member 160 and the inner surface 97. The support member may define the gap between the inner surface 97 and the support member 160. Thus, particles may be forced into the gap between the inner surface 97 and the support member 160 under centrifugal force. Therefore, a single filling step 46 can fill the hole 26 such that the conductive particles 62 continuously extend through the hole and can be overfilled, exposing more than one or both of the first surface 22 and the second surface 24 of the substrate 20. In one example, the support can be defined by a sacrificial layer deposited on the substrate 20 and can be removed from the substrate after the filling process is complete. For example, the sacrificial layer can be defined by a photoresist or any suitable alternative sacrificial material.

[0210] Optionally, as shown in FIG18A, the substrate 20 may define a trench 170 on a first side defining the first surface 22. The trench has a base 171 defining a first portion of the first surface 22. The trench 170 is formed in a second portion of the first surface 22. Therefore, the base 171 is offset from the second portion of the first surface 22 toward the second surface 24. Therefore, the first auxiliary member of the hole 26 and the resulting guide hole may terminate at the trench 170, and specifically at the base 171 of the trench 170. Therefore, the hole 26 and the resulting guide hole open into the trench 170. The second portion of the first surface 22 may be placed against the aforementioned support surface. Therefore, the first portion of the first surface 22 may be spaced apart from the support surface, thereby defining a gap between the first portion of the first surface 22 and the support surface. The gap may be defined by the trench 170, thus the first filling step may allow the second particle 62b to enter the trench 170. For example, the second particle 62b may substantially fill the trench 170. The substrate 20 may include an electrical conductor in the trench 170 that is electrically connected to the resulting via.

[0211] It should be understood that trench 170 can be a first trench of substrate 20, and substrate 20 can define a second trench configured as described above with respect to the first trench, but on a second side opposite to substrate 20. The second trench can therefore have a second substrate defining a first portion of the second surface 24. The second trench is formed in a second portion of the second surface 24. Therefore, a second base is offset from the second portion of the second surface 24 toward the first surface 22. Therefore, the second end of hole 26 and the resulting via can terminate at the second trench, and specifically at the base of the second trench. Thus, hole 26 and the resulting via open into the second trench. During the third filling step described above, the second particle 62b can be driven from the second surface 24 into the second trench and hole 26. That is, the third filling step can allow the second particle 62b to enter the second trench and hole 26. For example, the second particle 62b can substantially fill the second trench. Therefore, substrate 20 can include an electrical conductor in the second trench electrically connected to the resulting via.

[0212] While the gap can be defined by the trench in the substrate 20 as described above, it should be understood that the trench can be alternatively or additionally defined in the support member. The trench in the support member can define a base that is recessed from the support surface and aligned with the first end of the hole 26 in the substrate 20; therefore, the gap can be defined by the first surface 22 of the substrate 20 and the base of the trench in the support member. As a result, during the first filling step, a portion of the first port filler extends from the hole 26 in the substrate 20 into the trench of the support structure.

[0213] Optionally or additionally, the substrate 20 can be flipped so that the original inner surface 97 becomes the current outer surface 99, and the original outer surface 99 becomes the current inner surface 97. Then, the filling step 46 under centrifugal force can be repeated as a subsequent filling step. Therefore, where the centrifugal force 150 substantially enters the hole 26 from the first surface 22 in the first filling step, the centrifugal force can now substantially drive the particles from the second surface 24 into the hole 26 during subsequent filling steps under centrifugal force.

[0214] After one or more filling steps 46 under centrifugal force are completed, the particles 62 can then be compacted into the holes 26 and abutted against one or both of the first surface 22 and the second surface 24 during the pressing step 53, which is described in more detail below.

[0215] If compaction step 50 is performed, the resulting highly filled powder may occupy a length of the hole 26 less than the entire length of the hole, thereby defining the longitudinal distance between the first surface 22 and the second surface 24 of the body filler substrate 26, as described above. If the distance is greater than the predetermined distance as described above, at least one subsequent body filling step 46 as described above may be performed using one or more of the vacuum device 84, the suspended vacuum device 85, and the centrifuge, as needed. It should be understood that the hole is filled with the first and the opposite subsequently filled powder using one or both of the vacuum device 84 and the centrifuge 150. This includes filling the first subsequently filled powder in step 46. The next subsequent sequence 55 includes filling the opposite subsequently filled powder in step 46, optionally, as described above, the suspended vacuum device 85 may be used to fill the first and the opposite powder in sequence. Compaction step 50 may be performed after one or more or even all filling steps 46 as needed. Alternatively, compaction step 50 may be omitted. Once each distance is equal to or less than the predetermined distance, port filling step 46 of the type described above is performed.

[0216] Referring now to Figures 20A to 20F, filling step 46 can be performed by applying an electrostatic force to the particles 62 to drive the particles 62 into the orifice 26. Specifically, the electrostatic filling device 200 is configured to apply an electrostatic force to the suspension 60 to drive the particles into the orifice 26.

[0217] As shown in Figure 20A, an area of ​​the substrate 20 can be ablated, for example by laser ablation, to define a weakened region 202, which can then be removed in a later step to define the aperture 26. As shown in Figure 20B, a conductive layer 204 can be applied to the inner surface 97 of the substrate 20. For example, layer 204 can be a metal layer. In one example, the metal layer can be sputtered onto the inner surface 97 of the substrate 20. Next, as shown in Figure 20C, a non-reactive mask 206 can be applied to the conductive layer 204; for example, the non-reactive mask 206 can be a photoresist or other suitable material. Next, the ablated region can be etched to form the aperture 26. In this respect, although the aperture is shown as tapered, it should be understood that all apertures 26 described herein, and thus the resulting vias 34, can be shaped in any manner as needed. For example, the aperture 26 can be substantially cylindrical. Alternatively, the aperture 26 can be tapered. For example, the hole may taper inward from the outer surface 99 to the inner surface 97. Alternatively, the hole may taper outward from the outer surface 99 to the inner surface 97. The hole 26 can be defined in any suitable alternative shape as needed. It should also be understood that the substrate 20, as described in all examples herein, can be manufactured according to any suitable available method, including laser ablation and subsequent etching to form the hole 26.

[0218] As shown in Figure 20D, the suspension 60 can be applied to the outer surface 99 of the substrate 20 to cover at least a portion of the outer surface 99 as described above. Layer 204 may have a charge opposite to that of the particles 62; for example, the charge of the particles 62 may be defined by the aforementioned zeta potential. Layer 204 may have a surface charge. Optionally, layer 204 may be electrically connected to an electrode to which a charge is applied; in one example, layer 204 may define a negative charge, and particles 62 may carry a positive charge. The liquid medium 64 may be any suitable liquid that does not neutralize the electrical surface charge of the particles 62 relative to the attractive force of the oppositely charged layer 204 outside the suspension 60. Alternatively, particles 62 may be disposed in a paste. Alternatively or additionally, a charge may be applied to the particles opposite to the charge of layer 204.

[0219] During operation, layer 204 can electrostatically pull particles 62 into the holes 26 and displace the liquid medium 64 disposed in the holes 26. Thus, particles 62 can define a wet-filled powder of the type described above. The holes 26 can then be allowed to dry. It should be appreciated that, in one example, a force associated with charge can fill the entire length of the hole 26, as shown in FIG20E, where the charge can further encapsulate the particles 62 within the holes 26. In another example, the particles 62 can be filled in the manner described above with respect to compaction step 50. Of course, as mentioned above, compaction step 50 can be omitted. It should be understood that particles 62, including one or both of the first particle 62a and the second particle 62b, disposed in the holes 26, can contact the inner surface of the substrate 20 extending from the first surface 22 to the second surface 24, to at least partially define the holes 26 after the filling step, whether the filling step is performed under pressure differential, centrifugal force, or electrostatic force.

[0220] If compaction step 50 is performed, it should be understood that only one of the inner layers 122a and 122b (see Figures 8a-8b) enters the hole 26 at the outer surface 99 of the substrate 20. Optionally, the other of the inner layers 122a and 122b may abut against layer 204. Alternatively, layer 204 may be removed, and the other of the inner layers 122a and 122b may enter the hole 26 at the inner surface 97. Once compaction step 50 is completed, or if compaction step 50 is omitted, the final fill step may be performed alone or in combination with one or more subsequent fill steps. One or more subsequent fill steps and port fill steps (if performed) may be performed in the manner described herein. It should be understood that layer 204 may define a sputtered layer for the redistribution layer (RDL), as described in more detail below. Optionally, as FIG. 20F As shown in Figure 20F, layer 204 can be removed. It should be understood that this method is intended for use with a large number of holes of the type typically present on substrate 20. Layer 204 may cover multiple or all of the holes 26, thereby drawing particles 62 into each hole 26 in the manner described herein.

[0221] As shown in Figure 20G, the second charge 205 can be adjacent to the outer surface 99 of the particle 62 with the same charge. Therefore, the second charge 205 can exert a force driving the particle 62 along the outer surface 99. The particle 62 can be suspended as described above. Alternatively, the particle 62 can be dry. For example, the second charge can be a positive charge that repels the suspension 60 away from the second charge. The second charge can be applied at a location outside the pore array 26 such that the second charge drives the suspension 60 to flow across the outer surface 99 and into the pores 26 in the manner described above.

[0222] In another example, layer 204 can be provided as a sacrificial oxide layer, and a carrier layer can be disposed on the oxide layer. The redistribution layer can be applied to the outer surface 99 of the substrate 20, and the oxide can then be etched so that the redistribution layer can be applied to the inner surface 99 of the substrate 20.

[0223] Therefore, it can be appreciated that particles 62 can be pushed into the hole by forces from air pressure difference, centrifugal force, electrostatic force, or a combination thereof. Furthermore, it should be appreciated that one or more body portion filling operations can be performed. In some examples, a port filling operation can be performed after one or more body portion filling operations. Particles during the port filling operation can have an average size smaller than the average particle size during the body portion filling operation. In one example, the filling step can include filling the hole at a first side of the first defined surface 22 of the substrate 20, flipping the substrate, and filling the hole on a second side of the defined opposing second surface 24 of the substrate 20. Alternatively, it should be appreciated that the first step of filling the substrate can include introducing port filler into the hole at the first side of the substrate according to any filling step described herein, such that the port filler accumulates at the second side of the substrate. Thus, the port filler can extend from the second surface of the substrate into the hole. Alternatively or additionally, the first port filler can extend from the hole onto the second surface in the manner described above to define the button after the hard-pressing step. Next, a body portion filler can be introduced into the hole at the first side of the substrate according to any filling step described herein, such that the body portion filler extends from the first port filler toward the first surface. Finally, the second port filler can be introduced into the hole on the first side of the substrate according to any of the filling steps described herein, such that the second port filler substantially extends from the body portion to the first surface of the substrate. The phrases “to the first surface,” “substantially to the first surface,” “to the second surface,” “substantially to the second surface,” and similar expressions are intended to include termination at or substantially at the respective surface, and unless otherwise indicated, are intended to terminate outward from the respective surface. Alternatively or additionally, the first port filler can extend from the hole to the second surface in the manner described above to define a bulge after the hardening step.

[0224] Refer again FIG. 3 Once the filling step or step 46 has been completed to fill the holes 26 alone or in combination with one or more compaction steps 50, the particles 62 can be sintered in sintering step 52. It should be understood that the particles 62 can be dried prior to sintering step 52. Specifically, referring now to FIG. 14, the substrate 20 can be placed in a furnace 164 for a period of time at a temperature sufficient to sinter the particles 62 under any suitable pressure. For example, the pressure in the oven 164 can be atmospheric pressure. Alternatively, the oven 164 can be defined as a vacuum. The furnace may also include any suitable gas environment as needed. In one example, the sintering process is essentially a non-densification sintering process. It should be recognized that densification during the sintering process can cause portions of adjacent particles in the particles 62 to flow toward each other, thereby shrinking the resulting conductive filler 35.

[0225] Referring now to Figures 15A-15B, it is recognized that deformation of particle 62 can occur during substantially non-densifying sintering step 62; however, the deformation is relatively minimal compared to densifying sintering. For example, FIG. 15A Significant dedensification is illustrated, in which multiple adjacent particles 62 are in contact with each other and define corresponding geometric centers 159 spaced apart from each other by a first distance D1. After the substantially dedensification sintering step, the geometric centers 159 of two adjacent particles 62 define a second distance 2 between their respective geometric centers, as shown in Figure 15B. In one example, the difference between the second distance D2 and the first distance D1 is no greater than approximately 30% of the first distance. For example, the difference is no more than approximately 20% of the first distance. For example, the difference is no greater than approximately 15% of the first distance. In another example, the difference is no greater than approximately 10% of the first distance. For example, in a specific example, the difference is no greater than approximately 5% of the first distance. In a particular example, the first distance D1 may be substantially equal to the second distance D2.

[0226] It should be recognized that sintering includes an initial stage, whereby a neck of the particle extends between adjacent sintered particles to define a particle boundary 149 at the corresponding interface between adjacent sintered particles 62. It should be understood that particles 62 can be defined as powders referred to as “body nanostructures.” Each particle 62 can comprise a packed array of nanoparticles. In one example, each particle 62 can comprise at least one thousand to one million nanoparticles. However, it is anticipated that each particle 62 may comprise fewer than one thousand nanoparticles, for example, when the average particle size is 0.22 μm. During the initial stage of sintering, the nanoparticles constituting the particles 62 can expand or grow. When this occurs, pores within the particles 62 can move to the outer surface of the particles 62 and be removed. In the second or intermediate stage of sintering, the gaps 66 between adjacent particles 62 can shrink during the densification process of the particles 62. However, the densification of the particles 62 can be tuned by determining the average particle size in the initially synthesized particles 62 of the aforementioned suspension 60. The densification of particles 62 can be further tuned by determining the modal distribution of particles 62. For example, as shown above with reference to Figures 7 to... FIG. 7C The particle 62 can be defined as having a single-mode, dual-mode, or tri-mode distribution. It should be understood that the modal distribution of particle 62 does not affect the grain growth characteristics of the nanoparticles in each of particle 62. Rather, during sintering, the multimodal distribution can affect the densification characteristics of particle-to-particle interactions (e.g., necking).

[0227] It has been found that smaller nanoparticles result in greater nanoparticle growth during the first stage of densification. This greater nanoparticle growth during the first stage of densification leads to densification of particles 62 during the second or intermediate stage of densification. Furthermore, a greater initial density of conductive particles 62 in the pores 26 prior to sintering can also result in less densification of particles 62 during the second or intermediate stage of densification. It is recognized that a trimodal distribution has a greater initial density than a bimodal distribution. Moreover, a bimodal distribution has a greater initial density than a unimodal distribution. Therefore, a trimodal distribution of particles has a greater initial density than a unimodal distribution.

[0228] Therefore, in order to reduce densification during the second or intermediate sintering stage, it may be desirable to reduce the size of the nanoparticles forming particle 62. Furthermore, in order to reduce densification during the second or intermediate sintering stage, it may be desirable to provide bimodal or trimodal particle distributions. However, it should be recognized that the particles can be substantially non-densified and sintered in a single-modal distribution.

[0229] Without being bound by theory, it is considered that reducing the nanoparticle size, alone or in combination with providing a bimodal or trimodal particle distribution, can lower the overall achievable densification transition point between the intermediate and final stages of sintering. Unless otherwise stated, the density of particle 62 during the intermediate stages of sintering can be reduced such that the resulting sintered particle 62 is substantially non-dense. During the final stage of sintering, nanoparticles can grow in addition to the growth achieved during the initial sintering stage, which can be a precursor for sealing pores within particle 62. The final result after sintering is a continuous metal network filler within the vias, which can substantially extend from the first surface 22 to the second surface 24 without altering the coplanarity of the metallized vias with the surrounding substrate 20 (see Figure 2A). Furthermore, the continuous metal network filler can contact the first and second surfaces 24 of the substrate 20 at one or more, or even all, locations within the vias. The continuous metal network filler can extend from the vias from one or both of the first and second surfaces 24 of the substrate 20.

[0230] Therefore, it should be understood that the method of adjusting the densification of particles 62 during step 52 may include step 46 of filling the pores with conductive powder of the main nanostructure, each of the particles comprising a packed array of nanoparticles. The method may also include step 52 of sintering the particles in the pores within a temperature range for a duration. The method may further include a step of determining at least one of an average grain size and a modal distribution prior to the filling step to determine the amount of densification during the sintering step. As described above, the filling step may include filling the pores with a suspension of particles in a liquid medium and draining the liquid medium from the pores prior to the sintering step 52.

[0231] As described above, a majority of the particles 62 in the aperture 26 may be substantially non-densified sintered as described above. In one example, at least about 60% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. In another example, at least about 70% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. In yet another example, at least about 80% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. In yet another example, at least about 90% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. For example, in a particular example, at least about 95% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. More specifically, in one example, about 100% of the total volume of the particles 62 in the aperture 26 is substantially non-densified sintered. It should be understood that at least a portion of the filler defined by the non-densified sintered particles 62 in the hole 26 can contact the inner surface that defines the hole, extending from the first surface 22 of the substrate 20 to the second surface 24.

[0232] Sintering step 52 can occur at a sintering temperature ranging from approximately 100 degrees Celsius to approximately 400 degrees Celsius. In one example, the temperature range could be from approximately 200 degrees Celsius to approximately 400 degrees Celsius. For example, the temperature range could be from approximately 300 degrees Celsius to approximately 400 degrees Celsius. For example, the temperature range could be from approximately 300 degrees Celsius to approximately 350 degrees Celsius. For example, the sintering temperature could be approximately 325 degrees Celsius.

[0233] Sintering step 52 can be carried out for any suitable duration within any of the above-described temperature range to sinter particles 62 without substantially densifying them, as described above. For example, the duration can range from approximately 15 minutes to approximately 4 hours. In one example, the duration can range from approximately 30 minutes to approximately 2 hours. For example, the duration can be approximately 1 hour.

[0234] Advantageously, as described above, particles 62 can be ductile and malleable. As a result, particles 62 can have a coefficient of thermal expansion (CTE) that is not compatible with the substrate 20 without damaging the substrate 20 during sintering. In particular, the malleability of the silver particles 62 allows for non-densification sintering while maintaining the structural integrity of the substrate. Therefore, it should be understood that no material intended to make the CTE of the resulting particles 62 closer to that of the substrate 20 is added to either of the suspensions 60a and 60b. Thus, the sintered particles 62 do not contain any residue after the combustion of any CTE matching agent. For example, each of the first and second suspensions 60 can be without glass frit, i.e., without glass frit. Furthermore, in the example where the conductive material in the particles 62 is metallic, the resulting vias 34 can substantially define a single homogeneous metal from the first surface 22 of the substrate 20 to the second surface 24. For example, the first particle 62a and the second particle 62b (and therefore the body portion filler and the port filler) can be the same metal. In one example, the same metal can be silver. In another example, the same metal can be copper. Of course, it should be understood that the first and second particles 62a and 62b (and therefore the body portion filler and the port filler) can alternatively be different metals.

[0235] Alternatively or additionally, sintering step 52 may include the step of applying radio frequency (RF) current to particle 62, which is sufficient to generate eddy currents that cause particle 62 to be substantially non-densely sintered.

[0236] Referring now to Figures 21A-21B, prior to sintering the conductive filler, at least a portion of the conductive filler may be bonded to the inner wall 29 of the substrate 20. For example, the substrate 20 may include a conductive coating 210 bonded to each of the inner wall 29 and the particles 62. For example, the coating 210 may be bonded to each of the inner wall 29 of the port filler and each of the second particles 62b.

[0237] The coating 210 may extend from the inner surface to one or both of the first surface 22 and the second surface 24. The coating 210 may include a first portion 210a coated at a first end of the inner surface 29 of the substrate 26, and a second portion 210b coated at a second end of the inner surface 29 of the substrate. The second portion 210b is coated at the second end of the inner surface 29 of the substrate along the same direction separating the first surface 22 and the second surface 24. In one example, the first portion 210a of the coating extends from the first end of the inner surface 29 to the first surface 22 of the substrate 20, and the second portion 210b extends from the second end of the inner surface 29 to the second surface 24 of the substrate. Alternatively, the coating 210 may be positioned on the inner surface 29 without extending to either or both of the first surface 22 and the second surface 24.

[0238] The first portion 210a and the second portion 210b are spaced apart from each other along the inner surface 29 in a direction separating the first surface 22 and the second surface 24. Specifically, the first portion 210a of the coating 210 may extend along the inner surface 29 at a location aligned with at least a portion of the port filler extending from the body portion filler toward the first surface 22. The second portion 210b of the coating 210 may extend along the inner surface 29 at a location aligned with at least a portion of the port filler. At least a portion of the port filler extends from the body portion filler toward the second surface 222. Therefore, the coating 210 can ultimately bond the port filler to the substrate 20, and particularly to the inner surface 29.

[0239] In one example, coating 210 does not extend along inner surface 29 into the intermediate region of the resulting via 34, where the main filler portion is disposed in the intermediate region. Alternatively, coating 210 may extend along the entire inner surface 29 if desired. The conductive coating may further extend from inner surface 29 onto either or both of the first surface 22 and the second surface 24. For example, a first portion 210a may extend from inner surface 29 onto the first surface 22. A second portion 210b may extend from inner surface 29 onto the second surface 24.

[0240] The conductive coating 210 may include at least one metal, which is vapor-deposited onto the substrate 20 to define a first metal layer 212. The first metal layer 212 is thus bonded to the substrate and, in particular, to the inner surface 29. The at least one metal may also include a second metal layer 214, which is bonded to both the first metal 212 and the port filler, thereby bonding the port filler to the substrate 20. For example, the second metal may be vapor-deposited onto the first metal layer 212. In this respect, the first layer 212 may be referred to as an adhesion layer. The first metal may be at least one of titanium, chromium, tantalum, tungsten, and alloys including titanium-tungsten alloys. The first layer 212 may have any suitable thickness as needed. In one example, the thickness of the first layer 212 is in the range of about 1 nanometer to about 100 nanometers. For example, the thickness of the first layer 212 may be in the range of about 1 nanometer to about 50 nanometers. In one example, the thickness may be in the range of about 5 nanometers to about 10 nanometers.

[0241] The second layer 214 may be referred to as a bonding layer, which is bonded to the conductive particles 62b of the port filler. In one example, the second metal of the second layer 214 is miscible with the metal of the conductive particles 62b. Therefore, when the conductive particles 62b are silver particles, the second metal of the second layer 214 may be miscible with the metal of the second conductive particles 62b, which may be silver as described above or any suitable alternative metal. Thus, in one example, the second metal of the second layer may be miscible. Furthermore, the second metal may be a transition metal. For example, the second metal may be at least one or more of silver, copper, aluminum, palladium, and alloys including silver-palladium alloys. Thus, in some examples, the coating comprising the first layer 212 and the second layer 214, and therefore the first metal and the second metal, may be defined by the same single metal. Unless otherwise stated, the coating may comprise a single metal bonded to the inner surface of the glass substrate using, for example, vapor deposition, and sintered to the second conductive particles 62b.

[0242] The second layer 214 can be thicker than the first layer 212; for example, the second layer can have a thickness in the range of approximately 200 nanometers to approximately 5 micrometers. For example, the thickness can range from approximately 0.5 micrometers to approximately 2 micrometers. In other examples, it is recognized that the first layer 212 can be directly sintered with the conductive particles 62b of the port filler.

[0243] As described above, coating 210, particularly the first layer 212, can be applied to either or both of the first surface 29 and the second surface 24 via a vapor deposition process. For example, the vapor deposition process can be physical vapor deposition. Therefore, the first layer 212 can be applied to the inner surface 29 via ionized physical vapor deposition (iPVD), magnetron sputtering, DC sputtering, and evaporation deposition. Similarly, the second layer 214 can be applied to the first layer 212 via a vapor deposition process. For example, the vapor deposition process can be physical vapor deposition (PVD). Therefore, the second layer 214 can be applied to the first layer via ionized physical vapor deposition (iPVD), magnetron sputtering, DC sputtering, and evaporation deposition.

[0244] Once coating 210 has been bonded to the inner surface 29, a conductive filler, such as a port filler, can be bonded to coating 210. In one example, the port filler can be sintered to the second layer 214 during the sintering of particles into the via 26. In one example, the port filler can be a single-mode or multi-mode filler as needed. In one example, the port filler can be a bi-mode or tri-mode filler. In this regard, it should be understood that coating 210 defines the interface between the port filler and the inner surface 29 of substrate 26. This interface can form a barrier against gases that may permeate into the via 34. Alternatively or additionally, this interface can form a barrier against liquids that may permeate into the via 34.

[0245] It should be understood that the conductive coating 210 can be applied to the substrate 20 before performing the step of filling the hole 26 with the second conductive particle 62b to form a port filler. For example, the conductive coating 210 can be applied to the substrate 20 before performing the step of filling the hole 26 with the first conductive particle 62a to form a port filler. Therefore, the conductive coating 210 can be applied to the inner surface 39 before any conductive particle 39 is filled into the hole 26.

[0246] Optionally, the method may include performing a first filling operation step that forces a plurality of first conductive particles 62a into the hole 26. This first filling step can be applied using any suitable filling technique described herein. Once the entire first conductive particle 62a has been forced into the hole using one or more first filling steps, and the particle 62a has the required filling, the coating 210 can be applied to the substrate 26 in the manner described above. Therefore, the coating application step can occur after a first filling step that includes a plurality of first filling steps. The coating 210 can thus be further applied to at least one of the opposing outer ends of the body portion filler. For example, a first portion 210a of the coating can be applied to a first outer end of the body portion filler. A second portion 210b of the coating can be applied to a second outer end of the body portion filler opposite the first outer end, the second outer end being opposite the first outer end along the same direction separating the first surface 22 and the second surface 24 of the substrate 20. Next, at least one port-filling operation can be performed, which forces the second conductive particle 62b into the hole to define the port filling extending from the first conductive particle toward each of the first surface 22 and the second surface 24. As described above, the final filling operation can be performed under a vacuum under centrifugal force as described above, under electrostatic force as described above, or using any suitable alternative method as required. Once the coating has been applied to the inner surface 29 and the first particle 62a and the second particle 62b have been filled into the hole 26, the particles can be de-densified and sintered in the manner described above.

[0247] It should be understood that coating 210 can be vapor-deposited onto inner surface 29 in a vapor deposition chamber. Furthermore, the conductive particles 62, including first particle 62a and second particle 62b, can be non-densified and sintered in the same common vapor deposition chamber. Therefore, heat can be applied to the vapor deposition chamber, increasing the temperature within the chamber to a sintering temperature sufficient to sinter the first and second conductive particles. The sintering temperature can be in the range of about 100 degrees Celsius to about 400 degrees Celsius. For example, the sintering temperature can be in the range of about 300 degrees Celsius to about 400 degrees Celsius. In particular, the sintering temperature can be in the range of about 300 degrees Celsius to about 350 degrees Celsius. In a specific example, the sintering temperature can be about 325 degrees Celsius. Heat can be applied to the vapor deposition chamber in any suitable manner as needed. For example, radiant heat, conductive heat, or convective heat can be applied to the outer surface of the vapor deposition chamber to increase the temperature within the chamber.

[0248] Since particle 62 is non-densified sintered, the second particle 62b of the port filler can be sintered and bonded to the coating 210. In addition, when particle 62 is non-densified sintered, the first particle 62a (e.g., at one or both ends of the body portion filler) can be sintered and bonded to the coating 210.

[0249] In one example, heat can be applied to the vapor deposition chamber while the coating is being applied to the inner surface 29 of the substrate 20, thus allowing heat to be applied to the chamber simultaneously with the application of the coating (e.g., vapor deposition). Alternatively, after sintering is complete in the vapor deposition chamber, the temperature within the chamber can be reduced, allowing the coating 210 to be vapor-deposited onto the inner wall. Specifically, a first layer 212 can be vapor-deposited onto the inner surface 29, and a second layer 214 can be vapor-deposited onto the first layer 212. The elevated temperature inside the vapor deposition chamber during vapor deposition can be sufficient to sinter the particles 62 onto the coating 210; for example, vapor deposition can occur at a high temperature in the range of approximately 80 degrees Celsius to approximately 250 degrees Celsius.

[0250] Alternatively, coating 210 can be vapor-deposited onto inner surface 29 before the temperature in the vapor deposition chamber is increased to the sintering temperature. For example, before sintering, the temperature in the vapor deposition chamber can be cooled and maintained such that the temperature at inner surface 29 of substrate 20 is maintained below about 100 degrees Celsius during vapor deposition. For example, during vapor deposition, the temperature at inner surface 29 can be maintained in the range of about 0 degrees Celsius to about 80 degrees Celsius. The vapor deposition chamber can be cooled using any suitable means and methods as needed. For example, helium back-side cooling can be applied to the vapor deposition chamber. Optionally or additionally, a water jet can be used to lower the temperature of the vapor deposition chamber. Alternatively or additionally, multiple internal heat exchange tubes can carry cooling fluid within the vapor deposition chamber.

[0251] Once vapor deposition is complete, heat can be applied to the vapor deposition chamber to raise the temperature in chamber 241 to the aforementioned non-densification sintering temperature.

[0252] It should be understood that coating 210 may be applied to the inner surface of any suitable hole in substrate 20, regardless of whether the hole is metallized. In this respect, substrate 20 may include holes that are not metallized or otherwise conductive. Coating 210 may be applied to the inner surface of these holes to contribute to hole sealing.

[0253] It should be recognized that the resulting via 34 substantially contains only conductive material and air, if applicable, as described herein, except for any metal introduced into the via. Furthermore, as will now be described, the resulting via 34 can be hermetically tight.

[0254] Referring now to FIG. 27, the via 34 can be defined as any suitable size and shape as needed. For example, the via 34 can be generally hourglass-shaped, having first and second different conductive materials extending from a first surface of the substrate 20 to a second surface of the substrate 20. The inner surface of the hourglass-shaped via 34 can be defined as a cone of at least one to three degrees. Alternatively or additionally, the via 34 can contain metal deposited therein using different deposition techniques. For example, the via 34 can include a coating 210 applied to the inner surface of the via. The coating 210 can extend along the entire inner surface of the via to obtain the via 34. Furthermore, the coating can extend along a portion of each of the first and second opposing surfaces of the substrate 20.

[0255] The first layer of coating 210 can be electrolessly plated onto the inner surface of the hole. Therefore, as described above, the first layer can be referred to as an adhesion layer. The first layer can be a first metal, such as titanium. The second layer can be an electrically conductive layer of a second metal. For example, the second metal can be copper or silver. The second layer can be applied using electrochemical deposition. The second layer can be applied substantially uniformly along the first layer. The second layer can have a thickness in the range of about 3 micrometers to about 7 micrometers. As shown, coating 210 can be configured to not completely fill the narrowest portion or neck of the hole. A conductive filler 35 can be introduced into the hole according to any suitable method described above, such that the filler 35 occupies the remaining portion of the hole not occupied by the coating. Therefore, coating 210 and filler 35 can be combined to completely fill the neck of the hole 26 and form a conductivity. For example, filler 35 can be introduced under fluid pressure, centrifugal force, electrostatic force, or some combination thereof. Filler 35 can be sintered to the second layer in the manner described above.

[0256] Referring now to Figures 12A through 12C, in one example, a particle-filled substrate 20 can be placed in a chamber, and an oxidizing gas can be introduced into the chamber and forced through holes 26 at an elevated temperature, allowing oxides of the particles to escape from the corresponding holes. In one example, the elevated temperature can be greater than about 50 degrees Celsius and less than about 400 degrees Celsius. The chamber can be a vacuum chamber. Optionally or additionally, the chamber can be a sintering furnace. Once the particles 62 are dried, either by evacuating the liquid during the vacuum filling process described above, or by drying the particles after filling under centrifugal force, or by filling the holes using any suitable alternative method or approach described herein, the substrate 20 can be placed in the chamber.

[0257] In one example, when the substrate is positioned in the chamber, a nitrogen and oxygen mixture can be forced to flow through the orifice at a high temperature above ambient temperature. Therefore, the substrate, including particles 62, can be substantially exposed to an elevated temperature. In one example, the elevated temperature can be in the range of approximately 40 degrees Celsius to approximately 75 degrees Celsius. For example, the elevated temperature can be approximately 50 degrees Celsius. The temperature in the chamber is then increased to a level that causes the organic matter in the orifice to form oxides. For example, the temperature in the chamber can be increased to a level in the range of approximately 75 degrees Celsius to approximately 150 degrees Celsius. In one example, the temperature can be increased to approximately 120 degrees Celsius. The flow of the nitrogen and oxygen mixture through the orifice causes the oxides to be evacuated from particles 62 and thus from the orifice. The weight of the substrate can be monitored throughout the process, and it can be recognized that as the substrate decreases or the weight stops, it can be concluded that all the organic matter of the substantially formed oxides has been evacuated from the orifice.

[0258] Next, the nitrogen and oxygen mixture can be discharged from the orifice. Specifically, a cleaning gas can then be introduced into the chamber and forced to flow through the orifice of the substrate. In one example, the cleaning gas can be nitrogen. The nitrogen can be pure nitrogen. The cleaning gas removes the nitrogen and oxygen mixture from the orifice to prevent the metal particles 62 from oxidizing in the presence of the nitrogen and oxygen mixture. The cleaning gas can be added at a pressure ranging from about 0 Torr to about 760 Torr. Furthermore, the cleaning gas can be added at a temperature ranging from about 120 degrees Celsius to about 180 degrees Celsius.

[0259] Next, subsequent steps can be performed to remove the metal oxides formed during the step of flowing the nitrogen and oxygen mixture through the holes. These subsequent steps may include flowing a nitrogen and hydrogen mixture through the holes to remove the metal oxides from the holes. Finally, the nitrogen and hydrogen mixture can be discharged from the holes. Specifically, a cleaning gas can then be introduced into the chamber and forced to flow through the holes in the substrate. In one example, the cleaning gas may be nitrogen. The nitrogen may be pure nitrogen. The cleaning gas removes the nitrogen and hydrogen mixture from the holes. The substrate can then be sintered in the manner described above. Specifically, the substrate can be moved to a sintering furnace. Optionally, the chamber may be defined by the sintering furnace, such that the temperature within the chamber is increased to the sintering temperature as described above.

[0260] Specifically, referring again to Figures 3 and 22A-22B, once the substrate 20 has been sintered in step 52, the substrate 20 can undergo a compression step 53 to seal the interface between the substrate 20 and the particles 62. The interface may include a first interface between the sintered conductive filler and either or both of the first surface 22 and the second surface 24. Alternatively or additionally, the interface may include a second interface located between the substrate 20 and the sintered conductive filler at a position along the inner surface 29 toward or to the first surface 22, and further located along the inner surface 29 toward or to the second surface 22.

[0261] In one example, referring to Figures 22A to 22B, the pressing step 53 can be performed in a hard press 140. Specifically, the hard press 140 may include first and second extrusion surfaces 142 capable of contacting and pressing against a first surface 22 and a second surface 24 of the substrate 20. When particles 62 are interference-filled into the holes 26 such that they extend beyond the first surface 22 and the second surface 24 at their first and second ends, respectively, and during sintering, the resulting sintered conductive filler extends through the holes 26 and forms a first portion extending beyond the first surface 22 of the substrate 20 and a second portion extending beyond the second surface 24 of the substrate 20. The first and second portions of the conductive filler define corresponding first and second ends disposed outside the first surface 22 and the second surface 24, respectively, along the central axis of the holes 26. During the pressing step 53, the extrusion surfaces 142 may contact the first and second ends of the conductive filler. Specifically, at least one or both of the first extrusion surface 142 and the second extrusion surface 142 can be moved axially toward the other of the first extrusion surface and the second extrusion surface, and thus toward the corresponding first surface 22 and second surface 24. The extrusion step 53 can be referred to as a uniaxial pressing step.

[0262] One or both of the pressure plates 141 may move toward each other until the extrusion surface 142 contacts portions of the metal structure extending from either or both of the first surface 22 and the second surface 24, also known as the interference-filled portions of the conductive filler, which may be the metal filler as described above. As the extrusion surfaces 142 continue toward each other and thus toward the substrate 20, the extrusion surfaces 142 abut against the first surface 22 and the second surface 24 respectively, and extrude and sinter the first and second portions of the interference-filled conductive filler, as shown in FIG22 C. In particular, the metal structure may be deformed to define an I-beam structure having a waist 144 extending into the first surface 22 and the second surface 24 within the hole 26, and an outer protrusion 146 pressing against the first surface 22 and the second surface 24 respectively. The first and second portions of the conductive filler may define the outer protrusion 146. The outer protrusion 146 may be a flat outer protrusion 146. The outer bump 146 has an outer surface substantially parallel to the corresponding first surface 22 and second surface 24 of the substrate 20. Furthermore, the bump 146 can extend relative to the hole 26, and thus extend in a direction perpendicular to the hole 26, and thus extend relative to the guide hole 34.

[0263] The flat protrusion 146, pressed against the first surface 22 and the second surface 24, can seal the ends of the vias 34 at the two surfaces 22 and 24 of the substrate 20, respectively. Furthermore, it should be understood that at least some of the conductive fillers formed from the non-densified sintered particles 62 can become densified during the pressing step 43. Additionally, the interference-filled portion of the conductive filler can contact the substrate 20 at one or both of the first surface 22 and the second surface 24. The pressing surface 142 can also apply axial compressive force to the portion of the conductive filler disposed within the hole 26 along the central axis of the hole 26. Compression of the conductive filler in the hole 26 can cause the sintered particles 62 to seal against the inner surface 29 of the hole 26. Compression of the conductive filler on the substrate 20 can result in the vias 34 being hermetically tight. Therefore, the metallic structure of the vias 34 can be substantially non-porous at substantially each of the first surface 22 and the second surface 24. Furthermore, the interference fit between the flat outer end and the substrate 20 can resist or prevent the migration of the conductive filler body 35 during operation. Although the vias described herein provide improved electrical properties and are not bound by theory, it is believed that further densification of the conductive material could further improve certain aspects of the electrical properties of the resulting vias.

[0264] In one example shown in Figure 22A, the extrusion surface 142 can be defined by a corresponding pressure plate 141 of a uniaxial press. It is desirable that the pressure plate 141 be sufficiently flat at the corresponding extrusion surface 142, such that the corresponding outer surface of the protrusion 146 is also flat after deformation. Alternatively, as shown in Figure 22B, the extrusion surface 142 can be defined by an extrusion member 143 disposed between the pressure plate 141 and the corresponding first surface 22 and second surface 24 of the substrate 20. In one example, the extrusion member 143 can be carried by a corresponding surface of the pressure plate 141 facing the substrate 20. Thus, when at least one or both of the pressure plates 141 move toward each other, the extrusion surface 142 of the extrusion member 143 contacts the first and second ends of the particle 162 and applies force to the particle 162, thereby deforming the particle 162 as described above. The force applied to the particles 162 can be as high as approximately 300,000 pounds per square inch (PSI), for example, up to approximately 150,000 PSI. The extrusion member 143 can be defined by any suitable rigid incompressible material (such as glass, tungsten, or any suitable alternative material with suitable hardness) to compress the particles 62 without undergoing its own deformation, and the extrusion surface 142 can be flat before it contacts the particles 62, during the pressing of the particles 62 against the substrate 20, and after the hard pressing step 53 is completed, without reacting with the particles 62. Specifically, the flat extrusion surface 142 can be parallel to the first surface 22 and the second surface 24 of the substrate 20, respectively.

[0265] It can be appreciated that bump 146 can be formed without adding additional layers to the substrate that are intended to extend beyond either or both of the first surface 22 and the second surface 24 of the via 26 and the via 34. For example, bump 146 can be formed without attaching a sacrificial layer (such as a dry film resist) to either or both of the first surface 22 and the second surface 24 of the substrate 20 to intentionally extend the via 26. In this respect, filling step 46 can be performed without first attaching a dry film resist to surfaces 22 and 24. Thus, in one example, the via 26 or the via 34 does not include any portion of the resist extending beyond either the first surface 22 or the second surface 24. Furthermore, the via 26 and thus the via 34 can be filled with particles 62 without depositing a conductive layer, such as gold or titanium, onto the first surface 22 and the second surface 24 to intentionally extend the via 26 beyond the first surface 22 and the second surface 24. Therefore, in one example, the hole 26 or the guide hole 34 does not include a titanium or gold layer extending from either the first surface 22 or the second surface 24.

[0266] In some examples, the hard pressing step can be performed at ambient temperature and a heated temperature, and the filled particles can have a pre-finished surface. In some examples, the heated temperature can be sufficient to sinter all the particles in the corresponding pores during the hard pressing step.

[0267] Furthermore, the pressing step 53 can be performed at atmospheric pressure. Optionally, the pressing step 53 can be performed under a vacuum. For example, referring to Figures 23A-23B, the first and second rigid extrusion members 143 can be disposed within any suitable envelope, such as the envelope 118 described above with reference to Figures 8A-8B. Therefore, the envelope may include a first laminated structure 119a and a second laminated structure 119b. The first laminated structure 119a and the second laminated structure 119b may be impermeable relative to any airflow that may pass through them. It should be understood that the laminated structure 119a may be replaced by a single layer as needed. The substrate 20 can be placed between the opposing extrusion members 143 within the envelope, such that a first surface 22 faces the first extrusion member and a second surface 24 faces the other extrusion member 143. Thus, the first extrusion member 143 is disposed between the first surface 22 and the first structure 119a, and the second extrusion member 143 is disposed between the second surface and the second structure 119b. The interior of the envelope can be set in a vacuum environment as described above. Next, pressure plate 141 can apply pressure to the envelope, and specifically, pressure is applied to the first structure 119a and the second structure 119b, and pressure is applied to the extrusion member 143 within the envelope. Therefore, the respective extrusion surfaces of the extrusion member 143 apply a compressive uniaxial force against the substrate 20 to the conductive filler in the manner described above. Optionally, the pressing step 253 can be performed in an isostatic press, whereby isostatic pressure can be applied to the first and second extrusion members 143, causing the extrusion member 143 to apply a uniaxial force to the extruded conductive filler.

[0268] The uniaxial force can be applied for any suitable duration, ranging from seconds to several hours. The uniaxial force can also be applied while the substrate 20 is at any suitable temperature, from approximately 0 degrees Celsius to the melting temperature of the substrate 20; therefore, in one example, the pressing step 53 can be a cold-pressing step at room temperature. Alternatively, the pressing step can be a warm or hot-pressing step at a temperature above room temperature up to the melting temperature of the substrate 20. For example, the temperature can be as high as approximately 1200 degrees Celsius. During the pressing step, the temperature of the pressure plate 141 can be sufficient to cause the conductive filler to soften and deform, but not to liquefy it. The pressure plate 141 can heat the conductive filler directly or through the extrusion member 143. Therefore, in some examples, the pressing step 53 can forge the conductive filler. The uniaxial force can be in the range of up to approximately 100,000 PSI.

[0269] Alternatively, referring now to FIG. 24a, isostatic pressing can be applied to the substrate 20, and the conductive filler is disposed within an envelope between the first opposing structure 119a and the second opposing structure 119b. In one example, isostatic pressing is applied to the envelope, and structures 119a and 119b are extendable, allowing isostatic pressing to be applied directly to the substrate 20 and the conductive filler body. When isostatic pressing is applied to the envelope, the first structure 119a is adapted to the first surface 22 and the first end of the conductive filler, and the second structure 119b is adapted to the second surface 24 and the second end of the conductive filler. Thus, the first structure 119a and the second structure 119b apply isostatic pressure to the interference-filled portion of the conductive filler extending beyond the first surface 22 and the second surface 24 of the substrate 20. The isostatic pressure can be applied to the interference-filled portion of the conductive filler in a direction substantially perpendicular to the outer surface of the interference-filled portion. The first and second portions of the resulting filled conductive filler can be compressed and densified, and after applying isostatic pressure, a substantially dome-shaped outer surface is defined.

[0270] Optionally, referring to FIG24B, any suitable stretchable layer 127 can be disposed in the envelope and configured to apply isostatic pressure to the two opposite ends of the substrate 20 and the sintered conductive filler. Thus, the stretchable layer 127 can define a corresponding extruded surface configured to abut against an interference-filled portion of the sintered conductive filler body. The stretchable layer 127 can be made of any suitable high-temperature polymer, such as polytetrafluoroethylene (PTFE), or alternatively, a metal foil. In this regard, it should be understood that the stretchable layer 127 resists melting or decomposition. The stretchable layer 127 also advantageously resists adhesion to the substrate 20 and the conductive filler, or resists changes in the material composition of the substrate 20 and the conductive filler. Isostatic pressure is applied to the envelope, such that the isostatic pressure applied to the first structure 119a and the second structure 119b is applied to the first and second stretchable layers 127, respectively. Therefore, when isostatic pressing is applied to the envelope, the first stretchable layer 127 is adapted to the first surface 22 and the first end of the conductive filler, and the second stretchable layer 127 is adapted to the second surface 24 and the second end of the conductive filler. Thus, the stretchable layer 127 applies isostatic pressure to the interference-filled portion of the conductive filler extending beyond the first surface 22 and the second surface 24 of the substrate 20. The isostatic pressure can be applied to the interference-filled portion of the conductive filler in a direction substantially perpendicular to the outer surface of the interference-filled portion. The resulting filled first and second portions of the conductive filler can be compressed and densified, and define a substantially dome-shaped outer surface after the isostatic pressure has been applied.

[0271] During pressing step 53, isostatic pressing can be applied at room temperature (also known as cold isostatic pressing). Alternatively, isostatic pressing can be applied at elevated temperatures, up to about 2200 degrees Celsius, for example in the range of about 45 degrees Celsius to about 500 degrees Celsius. Therefore, the temperatures of structures 119a and 199b, individually or in combination with the stretchable layer 127, can be elevated relative to room temperature when isostatic pressing is applied to the substrate and the conductive filler. When isostatic pressing is applied at elevated temperatures, it is desirable to construct the encapsulation such that the first structure 119a and the second structure 199b do not melt to the substrate or the conductive filler. Isostatic pressing can be applied up to about 100,000 PSI.

[0272] Referring now back to Figure 3, it is understood that a pressing step 53 can be performed after the sintering step 52 as described above. Furthermore, the pressing step 53 can be performed alone or in combination with one or more compaction steps 50. Alternatively, the pressing step 53 can be performed in method 40, thereby omitting the compaction step 50. Alternatively, method 40 can include one or more compaction steps 50, thereby omitting the pressing step 53. When the method includes the pressing step 53 but not the pressing step 50, the outer portion of the conductive filler has a greater density at its outer end than the portion of the conductive filler extending from the first outer portion of the conductive filler to the second portion of the conductive filler.

[0273] In other examples, the pressing step 53 can be performed before the sintering step 52. Specifically, one or more filling steps 46 can be performed until the conductive particles cover the holes 26, such that the particles extend beyond the first surface 22 and the second surface 24 as described above. Then, after the pressing step 53, the conductive particles can be sintered at step 52 as described above. Alternatively, the sintering step 52 and the pressing step 53 can be performed simultaneously. That is, the conductive particles can be sintered under isostatic pressure during the pressing step 53; therefore, the pressing step 53 can be performed on the sintered conductive filler, the unsintered conductive particles, or sintered onto the conductive particles during their sintering.

[0274] In some examples, method 40 may include a step 54 of sealing the via (see Figure 3). In one example, the sealing step may be performed by polishing or surface-trimming particles 62. In particular, as shown in Figures 16A-16B, the outward-facing surfaces of the sintered particles 62 at each of the first surface 22 and the second surface 24 may be polished to increase the planarity of the outward-facing surfaces of the sintered particles 62. It should be appreciated that the outward-facing surfaces of the sintered particles 62 may be defined by port filling. For example, the outward-facing surfaces of the sintered particles 62 at each of the first surface 22 and the second surface 24 may be pressed by rods 166 driven on the respective surfaces. The hardness of the rods 166 may be higher than the hardness of the conductive material and lower than the hardness of the substrate. For example, the hardness may be higher than one or both of silver and copper, and lower than glass. Therefore, the rods 166 may cause the sintered particles 62 at each of the first surface 22 and the second surface 24 to change shape without compromising the integrity of the substrate. Specifically, the rod 166 can modify the shape of the interference-filled portion of the sintered particles at each of the first and second surfaces to seal the opening at one or more interfaces between the conductive material and the substrate 20. For example, the interfaces can be respectively located at the first surface 22 and the second surface 24 of the substrate 20. In one example, the rod 166 can be made of nickel. It should be appreciated that the sintered particles 62 at the first surface 22 and surface 24 can be defined by the port filler as described above. Thus, it can be said that the port filler defines the end cap 161 of the via 34. Furthermore, the end cap can hermetically seal the via. The surface of the end cap 161 can be finished as described above.

[0275] The rod 166 can be pressed into and moved over the port filler to form multiple gaps at the first and second ends of the through-hole for sealing with a conductive material. The ductility of silver or copper port fillers is particularly suitable for this purpose. Furthermore, the port filler can be pressed against one or more interfaces with the opening of the hole 26 through openings at each of the first surface 22 and the second surface 24 of the substrate 20. In one example, the sealing step 54 can be performed in a vacuum, such that both the substrate 20 and the rod 166 are positioned in a vacuum environment during the surface finishing process of the conductive material. It should be understood that the surface finishing step of the conductive material can further flatten the conductive material. Alternatively or additionally, sealing step 54 may include the following steps: vacuum depositing conductive material into conductive material at the end of the through hole to 1) seal one or two of the plurality of gaps, and 2) fill the opening at the interface between the conductive material and the substrate 20. Alternatively or additionally, sealing step 54 may include vacuum melting of conductive material to 1) seal one or two of the plurality of gaps, and 2) fill the opening at the interface between the conductive material and the substrate 20.

[0276] Sealing step 54 can produce an airtightness of less than about 10. -7 For example, the airtightness can be less than about 10. -8 For example, the airtightness can be less than about 10. -9 For example, the airtightness can be less than about 10. -10 For example, the airtightness may be less than about 10. -11 .

[0277] However, it should be recognized that the pressing step 53 and subsequent steps can replace the sealing step 54. Therefore, method 40 may include the pressing step 53 and omit the sealing step 54. Alternatively, method 40 may include the sealing step 54 and omit the pressing step 53b. Alternatively, it is conceivable that the method may include both the sealing step 54 and the pressing step 53. The pressing step 53 may be performed before the sealing step 54. Alternatively, the pressing step 53 may be performed after the sealing step 542. As shown in Figures 16A to 16B, it can be understood that the sealing step 54 may seal the ends of the guide hole 34 at the first and second sides of the substrate defining the first surface 22 and the second surface 24, respectively. Therefore, the guide hole 34 may be hermetically sealed. Therefore, the conductive material of the sintered particles 62, and thus also the conductive material of the guide hole 34, may be substantially non-porous at each of the first surface 22 and the second surface 24. In particular, the rod may scrape the particles along the outer surface of the glass. Alternatively, as described above, sealing step 54 can be omitted from method 40.

[0278] In some examples, sealing step 54 may include a selective laser sintering step, performed alone or in combination with one or both of pressing steps 53 and the step of driving the rod on the port filler as described above, which sinters one or both of the outer ends of the port filler to define a substantially non-porous dense end cap and further seal the guide hole 34. Thus, at least one or both outer ends of the port filler can define a substantially non-porous laser-melted end cap at their outer ends. Specifically, after step 52 (see FIG. 3), a laser can be selectively directed toward at least one or both ends of the port filler sufficient to melt the port filler and define a dense end cap. The laser directing step can be performed with controlled pulse time and laser intensity to melt the outer ends of the port filler, thereby defining a dense end cap. As described above, the port filler can fill beyond the hole such that the interference-filled portion of the port filler extends beyond either or both of the first outer surface 22 and the second outer surface 24 of the substrate (see, for example, FIG. 12B to FIG. 12C). The laser can be directed to the interference-filled portion of the port filler. In some examples, the laser can be a green laser. The sealed end cap can be a barrier that blocks any one or both of the gas and liquid that may penetrate into the orifice. As described in more detail below, the sealed end cap can be defined at least in part by sintered flakes or flake particles 225 (see Figure 25).

[0279] In other examples, instead of surface finishing with rods, polishing or grinding methods can be used to surface polish the particles. Specifically, the particles can be interference-filled and sintered as described above, and subjected to hard pressing or isostatic pressing before or after sintering as needed. In some examples, the interference-filled particles can be polished using a polishing substrate constructed as required, and in some examples, the polishing substrate is made of CeO2.

[0280] Optionally or additionally, a conductive adapter coating may be applied to the ends of the vias after sintering step 53. In this regard, the adapter coating may be applied after pressing step 53b. Optionally, the adapter coating may be applied before performing pressing step 53b. Optionally, the adapter coating may be applied when method 40 does not include pressing step 53. For example, the adapter coating may be applied to one or both of the outer surfaces 22 and 24 of the substrate and into vias that may be substantially planar with surfaces 22 and 24 of the substrate 20. The adapter coating may be applied to the ends of the vias using any suitable deposition technique as required. In one example, if a port filling step is performed, the adapter coating may be applied to the port-filling particles 62 at the ends of the vias. Alternatively, the adapter coating may be applied to the body portion-filling particles 62 at the ends of the vias. In one example, the adapter coating may be electroplated onto particles 62. Alternatively, the adapter coating can be deposited using various techniques such as evaporation, physical vapor deposition (PVD), or chemical vapor deposition (CVD) (e.g., atomic layer deposition (ALD)). Alternatively, the adapter coating can be applied via an electroless plating step.

[0281] It should be recognized that, as described above with reference to Figures 7A to 7C, the adapter coating may occupy, and in some instances, the adapter coating may fill, the gap 66 defined between adjacent particles. In some instances, the port filler may include palladium. Palladium may be present in any suitable amount, for example, from about 0.5% to about 30% by weight of the port filler. For example, from about 10% to about 30% by weight of the port filler. For example, in the bimodal distribution of the second particle 62b, the second bimodal particle may be defined by palladium as described above. Alternatively, the second bimodal particle may be at least partially or entirely bismuth. Alternatively, the second bimodal particle may be at least partially or entirely aluminum. Alternatively, the second bimodal particle may be at least partially or entirely tin. Alternatively, the second bimodal particle may be at least partially or entirely copper.

[0282] Optionally or additionally, after the final compaction step, any suitable metal may be deposited in the gaps between particles 62, particularly in particles 62b of the port filler. It should be appreciated that it may also be desirable to deposit metal in the gaps defined by the first particles 62a of the first filler. For example, in one example, an electroplatable metal may be electroplated into the gaps between silver particles 62 disposed in the holes. Thus, the electroplatable metal may at least partially or substantially fill the gaps. The electroplating step may be performed before sintering step 52 or after sintering step 54. The electroplatable metal may be any one or more, or even all, of aluminum, copper, titanium, silver, or any suitable alternative metal or alloy thereof, as required.

[0283] In another example, metal can be deposited into the gaps using any suitable process, such as chemical vapor deposition (CVD). Specifically, the method can be metal-organic chemical vapor deposition (MOCVD). For example, the process can be atomic layer deposition (ALD). The deposition can be performed under vacuum. The metal deposited in the CVD can be at least one of indium, aluminum, bismuth, copper, titanium, silver, or any suitable alternative metal as desired. The metal deposited in the gaps reduces the porosity of the filler. Therefore, when metal is deposited in the voids of the body portion filler, the porosity of the body portion filler is reduced. Similarly, when metal is deposited in the gaps of the port filler, the metal disposed in the gaps can reduce the porosity of the end cap defined by the port filler. CVD can occur before the particles of the body and the port filler are sintered. Alternatively, CVD can occur after the particles of the body and the port filler are sintered, but before the surface-trimmed end caps described above.

[0284] In yet another example, metal can be sputtered onto one or both of the body portion filler and the port portion filler. For example, metal can be sputtered onto the body portion filler before the port filler particles 62b are introduced into the hole. The metal can be sputtered before the body portion filler has been compacted. Alternatively, the metal can be sputtered onto the body portion filler after it has been compacted but before the particles are sintered. Or, the metal can be sputtered onto the body portion filler after the particles have been sintered. For example, in some examples, the body portion filler can be sintered before filling and then the port filler can be sintered. In this regard, it should be appreciated that during downstream processes, such as applications of redistribution layers, the body portion filler and the sputtered metal can be heated to elevated temperatures, causing the sputtered material to melt. The molten sputtered material can then travel into the voids of the body portion filler. The metal can be aluminum, copper, titanium, silver, indium, bismuth, tin, or any suitable alternative metal or alloy thereof, as needed.

[0285] Optionally or additionally, metal can be sputtered onto the port filler. For example, metal can be sputtered onto the port filler. Metal can be sputtered onto the port filler before it is compacted. Optionally, metal can be sputtered onto the port filler after it is compacted but before the particles are sintered. Therefore, the sintering temperature can melt the sputtered metal and allow it to enter the gaps. Alternatively, metal can be sputtered onto the port filler after the particles are sintered. Furthermore, metal can be sputtered onto the port filler before the port filler surface is completed, allowing the sputtered metal to enter the gaps, for example, when a redistribution layer is applied. Alternatively, metal can be sputtered onto the port filler before the port filler surface is completed. When it is recognized that the obtained surface-finished port filler may lack porosity for sputtered metal to enter the gap, it is understood that if porosity is generated during the port filler formation process, and particularly in the end cap, the sputtered metal can melt and flow into the hole during the application of the redistribution layer, thereby reducing the porosity of the port filler including the end cap.

[0286] Therefore, the adaptor coating deposited into the gaps can further seal the first surface 22 and the second surface 24 of the substrate 20. The sealing step prevents one or both of the gaseous and liquid contaminants from entering the pores and into the voids between adjacent particles. Alternatively or additionally, the sealing step can prevent one or both of the gaseous and liquid contaminants from entering the pores of the conductive material.

[0287] Referring now to Figure 25, the conductive filler, particularly the port filler, may comprise a plurality of sheets 25. Specifically, the sheets 25 may be deposited on the port filler. For example, the sheets 25 may be deposited on particles 62b of the port filler. In particular, the sheets 25 may be deposited on any one or both of the opposite ends of the port filler. As will be understood below, the sheets may be hard-pressed and sintered to define a substantially non-porous layer that provides a barrier against any one or both of the liquid and gas that may enter the aperture 26.

[0288] The sheet 25 can be irregularly shaped and can have different sizes and shapes. The average specific surface area of ​​the sheet 25 is in the range of about 0.3 m² / g to about 1.5 m² / g. For example, the specific surface area can be in the range of about 0.3 m² / g to about 1 m² / g. In one example, the specific surface area can be about 0.76 m² / g. Of course, it should be appreciated that the sheet 25 can have any suitable specific surface area as needed. In addition, most sheets can have an average aspect ratio in the range of about 2:1 to about 10:1. In one example, the sheet can be ball-milled. Alternatively, the sheet can be ground. Or, the flaky particles can be planetarily ground. Or, the sheet can be ball-milled. In this respect, it should be understood that the sheet can be manufactured in any suitable manner as needed. The sheet 25 can be the same metal as the port filler. Or, the sheet 25 can be a different metal than the port filler. Therefore, the sheet can be made of copper, silver, gold, aluminum, silver-plated copper, aluminum, etc.

[0289] When sheet 25 is extruded, for example using either or both of the hard press and isostatic press described herein, the sheet can break into sheet-like particles and be compacted at one or both outer ends of the port filler, thereby defining a layer disposed at one or both outer ends of the port filler. The sheet-like particles may have a density of, for example, from about 80% to about 98%. The sheet-like particles can be sintered to define a dense, substantially non-porous coating extending along the outer ends of the port filler. For example, sheet 25 can be applied to the port filler prior to the sintering step 52 described above. Alternatively, sheet 25 can be applied after the sintering step 52. Thus, sheet 52 can be sintered in subsequent operations, such as the application of a redistribution layer. Alternatively, the sheet can be sintered using laser sintering as described herein.

[0290] Finally, a redistribution layer (RDL) can be applied to the substrate 20 as needed. For example, referring now to Figures 17-18B, the redistribution layer 37 can be applied to one or both of the first surface 22 and the second surface 24 of the substrate 20, thereby being electrically connected to the via 34 and thus to the conductive material in the via. For example, a sputtered layer can be applied, and a conductive metal plating can be applied to the sputtered layer in a conventional manner. As shown in Figure 18A, optionally, a trench 170 can be formed on at least one of the corresponding first surface 22 and the second surface 24. It should be understood that the trench 170 can lead to the hole 26 and the via. Therefore, methods used to allow particles to enter the hole, such as vacuum, centrifugal force, and electrostatic force, can also be used to allow particles to enter the trench. The particles can be dried, packaged, and sintered as described above to define the redistribution layer 37.

[0291] It should be understood that the redistribution layer 37 can be constructed according to any suitable alternative embodiment. Referring now to FIG18C, the redistribution layer 37 may be disposed on at least one of the first surface 22 of the substrate 20 and the second surface 24 of the substrate 26. Thus, although the redistribution layer 37 is described as extending along the first surface 22 of the substrate 20, it should be understood that this description applies to the same forces and effects of a redistribution layer extending along the second surface 24 of the substrate 20.

[0292] In one example, the redistribution layer 37 may include a conductive adapter overlay 420 deposited on the first surface 22 and thus electrically connected to the via 34. For example, the overlay 420 may be vapor-deposited on the first surface 222. In one example, the overlay 420 may include a first layer 422 bonded to the substrate 20. (As mentioned above...) FIGS. 21A-21BThe conductive coating 210 is deposited on the first surface 22 of the substrate 20. The conductive adapter coating 420, particularly the first layer 422, may extend over and be deposited on the coating 210. The first layer 422 may be referred to as an adhesion layer. The first layer 422 may be defined by any suitable first metal. For example, the first metal may be titanium, tantalum, or an alloy of chromium, palladium, aluminum, titanium, tungsten, silver, or palladium. The first layer 422 may be vapor-deposited onto the first surface 222. Vapor deposition may be physical vapor deposition (PVD). Therefore, the first layer 422 may be applied to the first surface 22 by any of ionized physical vapor deposition (iPVD), magnetron sputtering, DC sputtering, and evaporation deposition. The first layer 422 may have any suitable thickness as needed. For example, the thickness may range from approximately 1 nanometer to approximately 100 nanometers. Specifically, the thickness of the first layer 422 can range from about 1 nanometer to about 50 nanometers, and in one example, the thickness can range from about 5 nanometers to about 10 nanometers.

[0293] The cladding layer 420 may further include a second layer 424 bonded to the first layer 422 and extending away from the substrate 20. The first layer 424 may be defined by any suitable second metal. For example, the second layer 424 may be defined by a second metal. The second metal may be silver, copper, or an alloy thereof. The second layer 424 may be vapor-deposited onto the first layer 422. The vapor deposition may be physical vapor deposition (PVD). Therefore, the second layer 424 may be applied to the first layer 422 by any of ionization physical vapor deposition (iPVD), magnetron sputtering, DC sputtering, and evaporation deposition. The second layer 424 may have any suitable thickness as needed. In one example, the thickness of the second layer 424 may be greater than the thickness of the first layer 422. For example, the thickness of the second layer 424 may be in the range of approximately 0.5 micrometers to approximately 3 micrometers. Therefore, the second layer 424 may be thicker than the first layer 422.

[0294] The overlay 420 can be patterned as needed. For example, a photoresist can be applied to the outer surface of the second layer 424 to expose the exposed portions of the second layer 424. Then, an etching process can be applied to the second layer 424 to remove the exposed portions of the second layer 424 and the alignment portions of the underlying first layer 422 (see Figure 18D). The etching process can be a wet etching process, or any suitable alternative etching process as needed, such as a dry etching process.

[0295] Referring now to Figure 18D, a conductive third layer 426 can be electroplated or electrochemically deposited onto the second layer. Therefore, the second layer 424 and the third layer 426 can be defined by a common metal. In one example, the common metal could be copper. In another example, the common metal could be silver. In yet another example, the common metal could be aluminum. The third layer 426 can have any suitable thickness as needed. For example, the third layer 426 can be thicker than the first layer 422. For example, the thickness of the third layer 426 can range from approximately 2 micrometers to approximately 10 micrometers.

[0296] Optionally, referring to FIG18E, the redistribution layer 37 may include a third layer 428 deposited on the second layer 424, for example, the third layer 428 may be vapor-deposited onto the second layer 424. Vapor deposition may be physical vapor deposition (PVD). Therefore, the third layer 428 may be applied to the second layer 424 by any of ionized physical vapor deposition (iPVD), magnetron sputtering, DC sputtering, and evaporation deposition. The third layer 428 may be configured as an anti-reflective metal layer. This anti-reflective metal layer is disposed on the second layer 424 and is designed to assist in patterning the second layer 424 (and the underlying first layer 422). The third layer may be made of any of titanium, tantalum, chromium, palladium, aluminum, and alloys of titanium, tungsten, silver, and palladium. The third layer 428 may have any suitable thickness as needed, for example, in the range of about 5 nm to about 100 nm.

[0297] The third layer 428 can be patterned as needed. For example, a photoresist can be applied to the outer surface of the third layer 428 to expose the exposed portion of the third layer 428. Next, an etching process can be applied to the third layer 428, removing the exposed portion of the second layer 428 and the aligned portions of the underlying second first layer 424 and first layer 422. Thus, the second layer 428 and first layer 424 can be patterned similarly. The etching process can be a wet etching process, or any suitable alternative etching process as desired, such as a dry etching process. Next, a fourth metal layer 430 can be deposited on the patterned third layer 428; for example, the fourth layer can be electrochemically deposited on the third layer 428. The fourth layer 430 can be copper, silver, or aluminum, etc. For example, the fourth layer 430 can be the same material as the second layer 424. The fourth layer 430 can have any suitable thickness as needed. For example, the fourth layer can be thicker than the second layer. Specifically, the fourth layer 430 may have a thickness in the range of about 2 micrometers to about 10 micrometers.

[0298] Alternatively, after the third layer 428 is patterned, the remainder of the third layer 428 can be removed. Specifically, the remainder of the third layer 428 can be selectively etched without removing the second layer 4244. Next, a metal layer can be deposited directly onto the second layer 4244. For example, the metal layer can be electrochemically deposited onto the second layer 424. The metal layer can be copper, silver, aluminum, or any suitable alternative metal. Therefore, the metal layer can be the same metal as the second layer 424. The metal layer can have any suitable thickness as needed. For example, the metal layer can have a thickness in the range of about 2 micrometers to about 10 micrometers.

[0299] Referring again to Figures 1A through 4, the resulting via 34 defines the conductive material of particle 62, which may be a metal and is defined by voids (also referred to as pores) between adjacent particles in a solid material, defined by the voids not filled in process 40. If applied as described above, the resulting via can further define an adapting coating. The conductive material of particle 62 can define a support frame designed to have internal gas voids or pores. These internal gas voids or pores are arranged substantially from the first surface 22 to the second surface 24 along a substantial portion of the via's length. The sintered conductive material defines a conductive path substantially from the first surface to the second surface. In some examples, the pores may define at least 25% of the total volume of the via. However, it should be understood that in other examples, the pores may define less than 25% of the total volume of the via. Furthermore, the pores may be arranged substantially uniformly along a substantial portion of the via's length. The resulting via can substantially define a non-linear conductive path substantially from the first surface 22 to the second surface 24. The resulting conductive web matrix, defined by sintered particles, can define at least one airflow path. This at least one airflow path extends from a first terminal end of the web matrix to a second terminal end. The first and second terminal ends can be defined by non-porous end caps.

[0300] Therefore, the mesh frame may include a conductive material comprising sintered and surface-finished particles that define a continuous conductive interconnect network substantially from the first surface 22 to the second surface 24 along most of the length of the via 26, wherein the conductive material is not fused to the substrate in the via 26 and wherein the conductive material defines a conductive path along the entire length of the via.

[0301] The conductive filler 35 of the via 34 can be defined by a framework of multiple conductive particles, which are packaged and subsequently sintered to bond adjacent particles to each other. As will be understood from the following description, the conductive path can be defined in any shape as needed. It is conceivable that at least a portion of the conductive path is non-linear.

[0302] It is desirable to fill the pores with non-gaseous materials to confine or eliminate expandable gases in subsequent processes, such as by applying a redistribution layer to substrate 20. In one example, the conductive filler may include silver or copper particles that may be mixed with other conductive materials to create a particle distribution whereby the other conductive materials may occupy some of the gaps defined by the silver or copper particles. Other conductive materials may include one or more of conductive polymers, conductive metals, conductive ceramics, conductive compounds, etc., such as graphene, conductive carbides, and intermetallic composites. Optionally or additionally, supercritical fluids have extremely low surface tension and can be used to deposit metals. It is conceivable that they can at least partially fill the gaps in the vias after a sintering step. Supercritical fluids carry metals with low surface tension, thus allowing the metal to enter compact spaces. Therefore, the metal can be deposited in the pores 26. Another option is to supercritically deposit nanoparticles in the pores, thereby occupying at least a portion of the gaps.

[0303] In one example, metal can be electroplated into the gaps of the port filler. The metal can be at least one or more of tungsten, copper, titanium, aluminum, silver, and alloys thereof. Alternatively or additionally, metal can be deposited into the gaps of the port filler (see Figures 7A to 7C). The metal can be at least one or more of tungsten, copper, titanium, silver, and alloys thereof. In one example, the metal can be deposited using a chemical vapor deposition process, for example, a metal-organic chemical vapor deposition process, a plasma-enhanced chemical vapor deposition process, or an atomic layer deposition process. Deposition can be performed under vacuum. Deposition can be performed after filling the port filler. Alternatively, deposition can be performed before sintering the filler. Or, deposition can be performed after sintering.

[0304] It should be recognized that methods for cleaning substrate 20 are provided as needed. For example, residual suspension can be removed from the first surface 22 and the second surface 24 as needed, including before the compaction step, before the sintering step, and before the surface finishing step. For example, residual suspension can be removed by using any suitable rod, driven along one or both surfaces 22 and 24 of substrate 20 in the manner described above. The rod may have a hardness higher than that of the residual suspension but lower than that of substrate 20. For example, the rod may be a Teflon rod or a rubber rod. Alternatively or additionally, an alcohol such as IPA may be placed alone or in combination with a soft semi-abrasive material on one or both of the first surface 22 and the second surface 24, and the rod may be driven along surfaces 22 and 24 in the manner described above to remove residual powder.

[0305] In another example, referring to FIG28, and as described above, the conductive via 34 may include a hole 26 extending at least into or through the substrate 20, and a sintered conductive material 135 establishing an electrical path from a first surface 22 of the substrate 20 to a second surface 24 of the substrate 20. The conductive material 135 may be defined by a sintered conductive filler 35 of conductive particles 62 as described herein. The sintered conductive filler 35 may at least partially define at least one pore, such as a plurality of pores. The pores may be arranged between the first surface 22 and the second surface 24 of the substrate 20. The at least one pore may be defined at least partially by the conductive particles 62 of the conductive filler body 35. For example, the pore may be defined by the void. The void is further defined by the conductive particles 62 as described above. Optionally or additionally, one or more holes may be defined between the conductive particles 62 of the conductive filler 35 and the inner surface of the substrate 20 defining the hole 26. If the conductive coating 210 is applied to the inner surface of the substrate 20, as described above with reference to FIG27, one or more holes can be defined between the coating 210 and the conductive particles 62 of the conductive filler 35.

[0306] In other examples, the conductive material 135 may be defined by a conductive paste containing conductive particles. An example of such a thick-film lead-free paste is described in PCT Publication No. WO 2018 / 094162A1, the disclosure of which is incorporated herein by reference. It should be appreciated that some conductive pastes may become porous after sintering. Sintered conductive paste may define at least one pore, such as multiple pores, at least partially. For example, shrinkage of the paste during sintering may create pores disposed between the inner surface of the substrate 20 and the sintered paste. If a coating is applied to the inner surface of the substrate 20, pores may be defined between the coating and the sintered paste. In other examples, the pores may be defined by the sintered paste itself. At least one pore defined by the paste may be disposed between the first surface 22 and the second surface 24 of the substrate 20.

[0307] It is desirable to fill the pores with a non-gaseous material to remove other gases occupying the pores from the vias. Gas removal limits or prevents gas expansion within the vias during subsequent processing, such as in the application of redistribution layers at high temperatures. The non-gaseous material can be a flowable viscous polymer 137 that hardens upon curing. Polymer 137 can be a conductive polymer. For example, the polymer can include multiple suspended metal particles. The metal particles can be silver, copper, gold, or any suitable conductive metal. Alternatively, the polymer can be a conductive polymer, recognizing that the conductive filler 35 can establish a conductive path from the first surface 22 to the second surface 24 of the substrate 20, regardless of whether the polymer is conductive or non-conductive. When the resulting conductive via 34 includes a capping layer 210, the capping layer 210 and polymer 137 can be combined to form a barrier to prevent possible penetration of one or both of the gas and liquid into the via 34.

[0308] When the conductive material 135 is defined by the conductive particles 62 of the filler 35, the filler 35 may include a body portion filler and a port filler extending from the body portion filler to either or both of the first surface 22 and the second surface 24, as described above. The pores of the filler 35 may form a network to establish a path from a first end of a via to a second end of a via. Similarly, when the conductive material 135 is a paste, the pores of the paste may form a network to establish a path from a first end of a via to a second end of a via. In such an example, a polymer can be introduced into the hole 26 under a pressure differential. For example, the polymer may be applied to one of the first surface 22 and the second surface 24 of the substrate 20, including the first and second ends of the via, and a negative pressure or vacuum may be applied to the other of the first and second surfaces. The first and second surfaces draw the polymer into the hole 26 through the pores. In other examples, it is recognized that the pores may not establish a path from the first end of the via to the second end of the via. Therefore, a vacuum will not be sufficient to draw the polymer into the orifice 26. In such an example, the polymer can be applied to either or both of the first surface 22 and the second surface 24, including the first and second ends of the guide hole, and pressed into the orifice 26. For example, a force from isostatic pressure or hard pressure can cause the polymer to be introduced into the orifice. When the polymer is introduced into the orifice, it flows into the orifice.

[0309] In some examples, both the bulk filler and the port filler are introduced into the holes and sintered. Then, polymer 137 can be introduced into the holes 26. In other examples, polymer 137 can be introduced into the holes 26 after the bulk bulk filler is introduced and before the port filler is introduced. At this point, the bulk filler can be sintered before the polymer 137 is introduced into the holes 26. Next, polymer 137 can be cured. Because the polymer reduces or substantially eliminates the porosity of the bulk filler, a vacuum may not be sufficient to draw the suspension including the port filler into the holes 26. Therefore, it may be desirable to introduce the port filler into the holes 26 under centrifugal or electrostatic force as described above. The port filler can then be sintered as described above. Before and / or after the port filler is sintered as described above, the port filler can be planarized at the first surface 22 and the second surface 24. If desired, the polymer can be introduced into the holes of the port filler under isostatic or hard pressure as described above. Alternatively, the metal can be introduced into the pores of the port filler in any of the suitable methods described above. For example, the metal can be electroplated onto the port filler to occupy at least one pore defined at least partially by the port filler. In this respect, in some examples, the conductive material 135 may refer to the body portion filler rather than the port filler.

[0310] Referring again to FIG. 28, the polymer 137 can be introduced into the hole 26 before or after the conductive material 135 is planarized on either or both of the first surface 22 and the second surface 24. In the example where the conductive material 135 is planarized after sintering, the planarization can substantially eliminate the voids at the first outer surface 22 and the second outer surface 24, thereby creating the hermetically tight via as described above. In these examples, the polymer 137 is introduced into the hole 26 before planarization. As shown in FIG. 28, the conductive material 135 has been planarized on the first surface 22 and the second surface 24 before sintering.

[0311] After polymer 137 is introduced into orifice 26, polymer 137 can be cured at any suitable temperature to harden polymer 137. In some examples, polymer 137 can be cured at approximately 300 degrees Celsius. Alternatively, the polymer can be cured at temperatures above or below approximately 300 degrees Celsius. In some examples, polymer 137 can be an adhesive. Polymer 137 can be a resin, or any suitable alternative form may be taken as needed. In some examples, polymer 137 can be a thermosetting polymer. In some examples, polymer 137 can be an epoxy resin. In other examples, polymer 137 can be a thermoplastic material. In some examples, polymer 137 can be a siloxane. In other examples, polymer 137 can be an ester. In other examples, polymer 137 can be a polyimide. In one specific embodiment, polymer 137 may be Ablebond® JM 7000 die-attach adhesive, which is commercially available from Ablestik Laboratories located at Rancho Dominguez, California, USA.

[0312] Once the polymer has cured, it is understood that residual polymer 137 may remain on either or both of the first surface 22 and the second surface 24. Therefore, residual polymer 137 may cover the conductive material 135 at the first and second additives of the through-hole. It may be desirable to remove the residual polymer 137 from either or both of the first surface 22 and the second surface 24, thereby exposing the conductive material 135 at either or both of the first and second ends of the through-hole 34. In some examples, residual suspension or residual polymer 137 can be removed by performing a chemical mechanical polishing (CMP) step on either or both of the first and second surfaces. For example, as... FIG. 28 As shown, after the polymer 137 is introduced into the holes 26 of the substrate 20 and cured, a certain amount of polymer 137 can be disposed on the conductive material 135, which, as described above, can be defined by the conductive filler 35. Optionally, as will be described in more detail below, the conductive material 135 can be defined by a thick film paste. A chemical mechanical polishing step can remove residual polymer 137 to expose the underlying conductive material 135 at each of the first and second ends of the substrate 20. Any suitable paste can be selected for selective CMP removal of the polymer 137.

[0313] Because the polymer 137 occupies at least a portion of all the holes defined by the conductive material 135, the resulting via 34 can be hermetically sealed. Alternatively or additionally, planarizing the conductive material 135 at the first and second ends of the via 34 can also seal the resulting via 34. Thus, the combination of introducing a polymer into the hole and planarizing the conductive material 135 can produce a hermetically sealed through-hole before and after subsequent processing (such as RDL processing).

[0314] Figure 26 illustrates an overview of an exemplary component 500 described above and throughout one aspect of the systems and methods disclosed herein. In this example, multiple devices may be mounted on interposer 21, with additional devices at the bottom. Interposer 21 may have several sections of through-glass vias or through-silicon vias of the type described above. Additional interposers or other types of layers are shown as part of the assembly structure of the devices. These layers may be used for additional interconnects. Some interconnects may be made at the top or bottom of interposer 21. In one example, an application-specific integrated circuit (ASIC) may be mounted to substrate 20 to at least partially define a die package. In another example, a silicon photonics chip may be mounted on the substrate to optically communicate with substrate 20. In yet another example, a transceiver may be mounted on a glass substrate to electrically communicate with a conductive material.

[0315] It should be understood that the illustrations and discussions of the embodiments shown in the accompanying drawings are for illustrative purposes only and should not be construed as limiting this disclosure. Those skilled in the art will understand that various embodiments are contemplated in this disclosure. Furthermore, it should be understood that the concepts described above having the above embodiments can be used alone or in combination with any other embodiments described above. It should also be understood that, unless otherwise stated, the various alternative embodiments described above with respect to one illustrated embodiment can be applied to all embodiments described herein.

Claims

1. An electrical component, comprising: A glass or sapphire substrate, the substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending from the first surface to the second surface; A conductive coating extending along the inner surface of the substrate, the conductive coating comprising a metal adhesion layer bonded to the inner surface and a second metal layer bonded to the adhesion layer; A hardened, non-conductive polymer placed in the pore; and An airtight end cap without holes at one end of the hole.

2. The electrical component according to claim 1, comprising an end cap without holes at the first and second ends opposite to the hole.

3. The electrical component of claim 2, wherein the non-conductive polymer extends between the end caps between the first and second ends of the hole.

4. The electrical component according to claim 3, wherein the non-conductive polymer comprises a resin.

5. The electrical component according to claim 3, wherein the non-conductive polymer comprises epoxy resin.

6. The electrical component according to any one of claims 1 to 2, wherein the adhesive layer comprises a transition metal.

7. The electrical component according to any one of claims 1 to 2, wherein the adhesive layer comprises titanium, tantalum, chromium, or an alloy thereof.

8. The electrical component according to any one of claims 1 to 2, wherein the adhesive layer comprises a titanium-tungsten alloy.

9. The electrical component according to any one of claims 1 to 2, wherein the first metal has a thickness ranging from 1 nanometer to 50 nanometers.

10. The electrical component of claim 9, wherein the thickness ranges from 5 nanometers to 50 nanometers.

11. The electrical component according to any one of claims 1 to 2, wherein the second metal layer comprises copper, silver, or aluminum.

12. The electrical component according to claim 11, wherein, The second metal layer has a thickness ranging from 200 nanometers to 5 micrometers.

13. The electrical component of claim 11, wherein the thickness of the second metal layer ranges from 0.5 micrometers to 5 micrometers.

14. The electrical component according to any one of claims 1 to 2, wherein the conductive coating is applied to the inner surface by a vapor deposition process.

15. The electrical component of claim 14, wherein the vapor deposition is physical vapor deposition.

16. The electrical component according to any one of claims 1 to 2, wherein the conductive coating is applied by any one of ionization physical vapor deposition, magnetron sputtering, DC sputtering, and evaporation deposition.

17. The electrical component according to any one of claims 1 to 2, further comprising a redistribution layer disposed on at least one of the first surface and the second surface of the substrate.

18. The electrical component of claim 17, wherein the redistribution layer comprises a vapor-deposited conductive coating.

19. The electrical component according to any one of claims 1 to 2, wherein the adhesive layer and the electrical conductor extend substantially throughout the inner surface.

20. The electrical component according to any one of claims 1 to 2, wherein the non-conductive polymer comprises a resin.

21. The electrical component according to any one of claims 1 to 2, wherein the non-conductive polymer comprises epoxy resin.

22. The electrical component according to any one of claims 1 to 2, wherein the hole extends linearly from the first surface to the second surface along a central axis.

23. An electrical component, comprising: A glass or sapphire substrate, the substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending from the first surface to the second surface; The hole has a first end near the first surface and a second end near the second surface; A conductive coating extending along the inner surface of the substrate, the conductive coating comprising a metal adhesion layer bonded to the inner surface and a second metal layer bonded to the adhesion layer; and The hardened non-conductive polymer placed in the pore The non-conductive polymer extends continuously from the first end of the pore to the second end of the pore.

24. The electrical component of claim 23, wherein the non-conductive polymer comprises a resin.

25. The electrical component of claim 23, wherein the non-conductive polymer comprises epoxy resin.

26. The electrical component according to any one of claims 23 to 25, wherein the adhesive layer comprises a transition metal.

27. The electrical component according to any one of claims 23 to 25, wherein the adhesive layer comprises titanium, tantalum, chromium, or an alloy thereof.

28. The electrical component according to any one of claims 23 to 25, wherein the adhesive layer comprises a titanium-tungsten alloy.

29. The electrical component according to any one of claims 23 to 25, wherein the first metal has a thickness ranging from 1 nanometer to 50 nanometers.

30. The electrical component of claim 29, wherein the thickness ranges from 5 nanometers to 50 nanometers.

31. The electrical component according to any one of claims 23 to 24, wherein the second metal layer comprises copper, silver, or aluminum.

32. The electrical component according to claim 31, wherein, The second metal layer has a thickness ranging from 200 nanometers to 5 micrometers.

33. The electrical component of claim 31, wherein the thickness of the second metal layer ranges from 0.5 micrometers to 5 micrometers.

34. The electrical component according to any one of claims 23 to 25, wherein the conductive coating is applied to the inner surface by a vapor deposition process.

35. The electrical component of claim 34, wherein the vapor deposition is physical vapor deposition.

36. The electrical component according to any one of claims 23 to 25, wherein the conductive coating is applied by any one of ionization physical vapor deposition, magnetron sputtering, DC sputtering, and evaporation deposition.

37. The electrical component according to any one of claims 23 to 25, further comprising a redistribution layer disposed on at least one of the first surface and the second surface of the substrate.

38. The electrical component of claim 37, wherein the redistribution layer comprises a vapor-deposited conductive coating.

39. The electrical component according to any one of claims 23 to 25, wherein the adhesive layer and the electrical conductor extend substantially throughout the inner surface.

40. The electrical component according to any one of claims 23 to 25, wherein the non-conductive polymer comprises a resin.

41. The electrical component according to any one of claims 23 to 25, wherein the non-conductive polymer comprises epoxy resin.

42. An electrical component, comprising: A glass or sapphire substrate, the substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending linearly from the first surface along a central axis to the second surface; A conductive coating extending along the inner surface of the substrate from the first surface to the second surface, the conductive coating comprising a metal adhesion layer bonded to the inner surface and a second metal layer bonded to the adhesion layer; and A hardened, non-conductive polymer placed in the pore.

43. The electrical component of claim 42, comprising a holeless end cap at the opposite first and second ends of the hole.

44. The electrical component of claim 43, wherein the non-conductive polymer extends between the end caps between the first and second ends of the aperture.

45. The electrical component of claim 44, wherein the non-conductive polymer comprises a resin.

46. ​​The electrical component of claim 44, wherein the non-conductive polymer comprises epoxy resin.

47. The electrical component according to any one of claims 42 to 43, wherein the adhesive layer comprises a transition metal.

48. The electrical component according to any one of claims 42 to 43, wherein the adhesive layer comprises titanium, tantalum, chromium, or an alloy thereof.

49. The electrical component according to any one of claims 42 to 43, wherein the adhesive layer comprises a titanium-tungsten alloy.

50. The electrical component according to any one of claims 42 to 43, wherein the first metal has a thickness ranging from 1 nanometer to 50 nanometers.

51. The electrical component of claim 50, wherein the thickness ranges from 5 nanometers to 50 nanometers.

52. The electrical component according to any one of claims 42 to 43, wherein the second metal layer comprises copper, silver, or aluminum.

53. The electrical component according to claim 52, wherein, The second metal layer has a thickness ranging from 200 nanometers to 5 micrometers.

54. The electrical component of claim 52, wherein the thickness of the second metal layer ranges from 0.5 micrometers to 5 micrometers.

55. The electrical component according to any one of claims 42 to 43, wherein the conductive coating is applied to the inner surface by a vapor deposition process.

56. The electrical component of claim 55, wherein the vapor deposition is physical vapor deposition.

57. The electrical component according to any one of claims 42 to 43, wherein the conductive coating is applied by any one of ionization physical vapor deposition, magnetron sputtering, DC sputtering, and evaporation deposition.

58. The electrical component according to any one of claims 42 to 43, further comprising a redistribution layer disposed on at least one of the first surface and the second surface of the substrate.

59. The electrical component of claim 58, wherein the redistribution layer comprises a vapor-deposited conductive coating.

60. The electrical component according to any one of claims 42 to 43, wherein the adhesive layer and the electrical conductor extend substantially throughout the inner surface.

61. The electrical component according to any one of claims 42 to 43, wherein the non-conductive polymer comprises a resin.

62. The electrical component according to any one of claims 42 to 43, wherein the non-conductive polymer comprises epoxy resin.

63. The electrical component according to any one of claims 42 to 43, wherein the non-conductive polymer extends continuously from the first end of the aperture to the second end of the aperture.

64. An electrical component, comprising: A glass substrate, the glass substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending from the first surface to the second surface; as well as A conductive filler is disposed in the hole to at least partially define a conductive via, wherein the conductive via defines a conductive path from the first surface to the second surface, wherein the conductive filler comprises a plurality of sintered conductive sheet-like particles.

65. An electrical component, comprising: A substrate, the substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending from the first surface to the second surface; And a conductive filler comprising conductive particles that substantially extend from the first surface to the second surface to at least partially define a conductive via, wherein the conductive via defines a conductive path substantially from the first surface to the second surface; as well as A conductive coating that bonds at least a portion of the conductive filler to the inner surface.

66. A method for metallizing a hole in a substrate extending from a first surface to an opposing second surface, the method comprising the steps of: The substrate is placed on a support member such that a first surface of a first side of the substrate faces the support member, and a second surface of a second side of the substrate opposite the first surface is exposed, wherein a portion of the first surface is spaced apart from at least a portion of the support surface of the support member. Under the action of centrifugal force, at least one filler is introduced into a hole on the first side of the substrate, such that at least one filler extends outward beyond the first surface.

67. A method for filling a hole defined by an inner surface of a glass substrate, the glass substrate extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of first conductive particles into the hole to define the body portion filling; Apply a conductive coating to the inner surface; After the application step, at least one port filling operation is performed, which forces a plurality of second conductive particles into the hole to define a port filling extending from the first conductive particle toward each of the first surface and the second surface; as well as The first conductive particle and the second conductive particle are sintered to create a conductive via, the conductive via defining a conductive path along the direction.

68. A method for filling a hole defined by an inner surface of a glass substrate, the glass substrate extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of conductive particles into the hole to define a conductive filler that defines opposite ends; after performing the step, apply a conductive sheet to at least one of the opposite ends of the conductive filler; as well as Following the application step, the conductive particles and the conductive sheet are sintered to at least partially define conductive vias, wherein the conductive vias are conductive paths from the first surface to the second surface.

69. A method of filling a hole defined by an inner surface of a glass substrate, the glass substrate extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of first conductive particles into the hole to define the body portion filling; After the execution step, at least one port filling operation is performed, which forces a plurality of second conductive particles into the hole to define a port filling extending from the first conductive particle toward each of the first surface and the second surface, wherein the port filling defines a plurality of gaps between the second conductive particles; as well as After the final filling step, metal is introduced into the voids.

70. A method for filling a hole defined by an inner surface of a glass substrate, the glass substrate extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of first conductive particles into the hole to define the body portion filling; After the execution step, at least one port filling operation is performed, which forces a plurality of second conductive particles into the hole to define a port filling extending from the first conductive particle toward each of the first surface and the second surface, wherein the port filling defines a plurality of gaps between the second conductive particles; as well as When the substrate is placed in the chamber, a mixture of nitrogen and oxygen flows through the holes.

71. A method of filling a hole defined by an inner surface of a glass substrate, the glass substrate extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of first conductive particles into the hole to define the body portion filling; After the execution step, at least one port filling operation is performed, which forces a plurality of second conductive particles into the hole to define a port filling extending from the first conductive particle toward each of the first surface and the second surface; Sintered body filling and port filling to at least partially define conductive vias; as well as After the sintering step, a laser is directed to at least one end of the port filler sufficient to melt the end of the port filler and define a substantially non-porous end cap.

72. A method of manufacturing a conductive component, the conductive component comprising a glass substrate having a first surface and a second surface opposite to the first surface, and a hole extending from the first surface to the second surface, the method comprising the steps of: Perform at least one filling step, which forces a plurality of first conductive particles into the hole to define the body portion filler; Perform at least one port filling operation, which forces a plurality of second conductive particles into the hole to define a port filling extending from the first conductive particle toward at least one of the first surface and the second surface; The sintered body portion filler and port filler at least partially define conductive vias; A conductive coating vapor is deposited onto at least one of the first surface and the second surface that are electrically connected to the via; as well as The conductive coating is patterned.

73. A method of manufacturing a conductive component, the conductive component comprising a glass substrate having a first surface and a second surface opposite to the first surface, and a hole extending from the first surface to the second surface, the method comprising the steps of: Perform at least one main portion filling step, which forces a plurality of first conductive particles into the hole to define the main portion filler; Perform at least one port filling operation, which forces a plurality of second conductive particles into the hole to define a port fill extending from the first conductive particle toward at least one of the first surface and the second surface; Prior to the second execution step, at least one of the body portion fillers is compacted at a temperature ranging from about 120 degrees Celsius to about 250 degrees Celsius before the second execution step and the port filling. At least one of the first conductive particles and the second conductive particles is coated with an anti-caking agent.

74. A method for manufacturing an electrical component, comprising the following steps: A suspension of copper particles in a liquid medium is introduced into a hole, which extends laterally from the first surface of the glass substrate to the second surface of the glass substrate opposite to the first surface. The liquid medium is extracted from the orifice to form a conductive filler, wherein the extraction step removes a portion of the copper oxide from the copper particles; as well as The copper particles are sintered to define a conductive framework having a first end and a second end opposite to each other along the transverse direction, wherein the conductive framework defines a conductive path from the first end to the second end.

75. A method for manufacturing an electrical component, comprising the following steps: A suspension of copper particles in a liquid medium is introduced into a hole, which extends laterally from the first surface of the glass substrate to the second surface of the glass substrate opposite to the first surface. The liquid medium is discharged from the orifice; as well as The copper particles are sintered to define a conductive frame having a first end and a second end opposite each other along the transverse direction, wherein the conductive frame defines a conductive path from the first end to the second end, and wherein the sintering step substantially removes copper oxide from the copper particles.

76. A method for manufacturing an electrical component, comprising the following steps: At least one suspension is introduced into a hole extending through a glass substrate from a first surface to a second surface of the glass substrate, wherein the at least one suspension comprises a first bimodal particle and a second bimodal particle, wherein the first bimodal particle and the second bimodal particle comprise different metals, and the second bimodal particle has a lower melting point than the first bimodal particle. The liquid medium is discharged from the orifice, such that the second bimodal particle is disposed in the void defined by the first bimodal particle; as well as The first bimodal particle and the second bimodal particle are sintered in the hole to define a conductive frame having a first end and a second end opposite to each other along the lateral direction, wherein the conductive frame defines at least a portion of a conductive path from the first end to the second end.

77. A method for manufacturing an electrical component, comprising the following steps: At least one suspension is introduced into a hole extending laterally from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, wherein the at least one suspension comprises a first bimodal particle and a second bimodal particle. The liquid medium is discharged from the orifice, such that the second bimodal particle is disposed in the void defined by the first bimodal particle; as well as The first bimodal particle and the second bimodal particle are sintered in the hole to define a conductive frame having a first end and a second end opposite to each other along the lateral direction, wherein the conductive frame defines a conductive path from the first end to the second end.

78. An electrical component, comprising: A substrate, the substrate defining a first surface and a second surface opposite to the first surface, and an inner surface defining a hole extending from the first surface to the second surface; A sintered conductive material, the sintered conductive material substantially extending from the first surface to the second surface to define a conductive via, wherein the sintered conductive material defines a conductive path substantially from the first surface to the second surface; as well as A polymer disposed in at least one pore defined by the sintered conductive material.

79. A method for filling a substrate hole, the hole being defined by an inner surface of the substrate, the inner surface substrate extending from a first surface of the substrate in one direction toward a second surface of the substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step to introduce conductive material into the hole; The conductive material is sintered to create at least one pore, the at least one pore being defined at least partially by the conductive material; After the sintering step, a polymer is introduced into the pores to at least partially fill the at least one pore.

80. A method for filling a hole defined by an inner surface of a glass substrate, the inner surface extending from a first surface of the glass substrate to a second surface of the glass substrate opposite the first surface, the method comprising the steps of: Perform at least one filling step to overfill the hole with a plurality of conductive particles such that the particles extend beyond the first surface and the second surface of the substrate; After the at least one filling step, the conductive particles are sintered to produce a sintered conductive fill extending through the hole, and having a first portion extending beyond the first surface of the substrate and a second portion extending beyond the second surface of the substrate. After the sintering step, a compressive force is applied to the first and second portions of the conductive filler to seal the interface between the sintered conductive filler and the glass substrate.

81. A method for filling a hole defined by an inner surface of a glass substrate, the inner surface extending from a first surface of the glass substrate to a second surface of the glass substrate opposite to the first surface, the method comprising the steps of: Perform at least one filling step to overfill the hole with a plurality of conductive particles such that the particles extend beyond the first surface and the second surface of the substrate; Following the at least one filling step, a compressive force is applied to the first and second portions of the conductive filler to seal the interface between the sintered conductive filler and the glass substrate. The step of applying the compressive force is performed at a temperature suitable for sintering the particles.

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