Glass insert and method of manufacturing a glass article

Abstract

A method of making a glass article, comprising: (A) forming a first layer of catalytic metal on a glass substrate; (B) heating the glass substrate; (C) forming a second layer of an alloy of a first metal and a second metal on the first layer; (D) heating the glass substrate, thereby forming a glass article, the glass article comprising: (i) the glass substrate; (ii) an oxide of the first metal covalently bound to the glass substrate; and (iii) a metal region bound to the oxide, the metal region comprising the catalytic metal, the first metal, and the second metal. In embodiments, the method further comprises: (E) forming a third layer of a primary metal on the metal region; and (F) heating the glass article, thereby forming a glass article, the glass article comprising: (i) the oxide of the first metal covalently bound to the glass substrate; and (ii) a new metal region bound to the oxide, the new metal region comprising the catalyst, the first metal, the second metal, and the primary metal.

Description

Background Technology

[0001] This application claims priority to U.S. Provisional Application No. 63 / 009,708, filed April 14, 2020, in accordance with the Patent Act, the entire contents of which are incorporated herein by reference.

[0002] Semiconductor packaging technology has been developing rapidly for many years. In the early days, methods for packaging more complex semiconductor circuits (and thus achieving higher functionality and performance in a given package) increased the two-dimensional size of the semiconductor chip within the package. In practice, it is not possible to expand laterally in two dimensions without limitation, because the final design will encounter difficulties such as power signal routing complexity, power consumption issues, performance issues, and manufacturing yield issues.

[0003] Therefore, efforts have been made to vertically extend semiconductor chips. These efforts have resulted in so-called 2.5D and 3D integrated circuits, which interconnect two or more semiconductor chips within a single package using interposers. As used herein, the term "interposer" generally refers to any structure that extends or completes an electrical connection between two or more electronic devices. The primary function of an interposer is to provide interconnectivity, allowing two or more semiconductor chips to utilize high terminal spacing and avoiding the need for through-vias through the semiconductor chip itself. The technique involves flipping the semiconductor chip from its conventional configuration, orienting the chip substrate upwards and the chip side downwards. High-pitch microbump terminals are provided to the chip, which are then connected to corresponding terminals on the top side of the interposer. The bottom side of the reversed interposer is connected to the (typically organic) package substrate via suitable terminals, which are typically Controlled Collapse Chip Connection (C4) solder joints. The insert is provided with through-vias through the substrate, so that an electrical connection can be made from the semiconductor chip terminal on the top side of the insert to the package substrate terminal on the bottom side of the insert.

[0004] To date, the bottom substrate of the interposer has typically been silicon. Metallized vias provide a path for electrical signals to pass through the interposer, between opposite sides. While silicon interposers are a promising and effective technology for achieving vertical integration of semiconductor chips, they present challenges, particularly regarding coefficient of thermal expansion (CTE) mismatch throughout the stack, including CTE mismatch between the silicon interposer and the organic packaging substrate. Undesirable CTE mismatch can lead to interconnect failures between the semiconductor chip and the silicon interposer, and / or between the silicon interposer and the packaging substrate. Furthermore, silicon interposers are relatively expensive and suffer from high dielectric losses due to the semiconductor properties of silicon.

[0005] Organic inserts have been introduced (e.g., Flame Retardant 4; FR4). However, organic inserts present problems with dimensional stability.

[0006] Glass, as a substrate for inserts, solves many of the problems associated with silicon and organic inserts. Glass is a substrate material that is highly advantageous for electrical signal transmission because it has good dimensional stability, a tunable coefficient of thermal expansion (“CTE”), low power loss at high frequencies, high thermal stability, and can be formed in thicknesses and large panel sizes.

[0007] However, metallizing through-holes in glass substrates to provide conductive paths has proven problematic and difficult. Some conductive metals (particularly copper) do not adhere well to glass, including both the main planar surface and the sidewall surfaces of the through-holes. It is suspected, without being theoretically limited, that poor adhesion of conductive metals to glass is a result of the difference in the type of adhesion used—fixing the metal together on one side and the glass together on the other. Simply put, glass is a network of covalently bonded oxide molecules (e.g., silicon dioxide, aluminum oxide, and boron oxide). Metals are composed of an electron "sea" that moves freely within a lattice of fixed cation nuclei. The glass adhesion mechanism is fundamentally different from the metal adhesion mechanism, thus limiting the adhesion between metal and glass. This problem can be mitigated by roughening the glass surface to which the metal is to be bonded, which provides a mechanical interlock between the metal and glass. However, roughening the glass surface introduces additional problems and is not ideal in terms of methodology. Accordingly, new methods are needed to address the following issues: metallizing through-holes in glass substrates intended for use as inserts; and adhering the metal to the glass substrate. Summary of the Invention

[0008] This disclosure addresses these two problems by electroless plating of a glass substrate surface in a solution comprising a salt of a first metal that readily forms oxides at the surface (forming covalent bonds with the oxide-rich glass substrate) and a salt of a second metal (e.g., copper) that is less prone to forming such oxides. After heat treatment, the glass article is formed from an oxide of the first metal and metal regions, the oxide of which is covalently bonded to the glass substrate surface, and the metal regions (including the first and second metals in metallic form) bonded to the oxide of the first metal. A thicker layer of the second metal (or some other metal) can then be electroplated over the metal regions of the glass article. After another heat treatment, the glass article is formed from an oxide of the first metal and metal regions, the oxide of which remains covalently bonded to the glass substrate surface, the metal regions comprising the first and second metals in metallic form bonded to the oxide of the first metal. The first metal, readily forming oxides at the surface, serves as an adhesive bridge between the oxide-rich glass substrate and the second metal to be bonded to the glass substrate. As an example, the first metal is manganese, and the second metal is copper. First, a nanolayer of metal (e.g., silver) can be applied to the surface of a glass substrate using a solution-based process (e.g., spin coating) to catalyze the electroless deposition of the first and second metals.

[0009] According to a first aspect of this disclosure, a method for manufacturing a glass article includes: (A) forming a first layer of a catalytic metal on a glass substrate surface; (B) subjecting the glass substrate having the first layer of the catalytic metal to a temperature of 150°C to 600°C for at least 2 minutes; (C) forming a second layer of an alloy of a first metal and a second metal on the first layer; and (D) subjecting the glass substrate having the second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal to a temperature of 250°C to 600°C for at least 30 minutes, thereby forming a glass article comprising: (i) a glass substrate; (ii) an oxide of a first metal covalently bonded to the glass substrate; and (iii) a metal region bonded to the oxide of the first metal, the metal region comprising the catalytic metal in elemental form, the first metal in elemental form, and the second metal in elemental form.

[0010] According to a second aspect of this disclosure, the method of the first aspect further includes: forming a third layer of a primary metal on a metal region of the glass article.

[0011] According to a third aspect of this disclosure, the method of the first aspect further includes: subjecting a glass article having a third layer of a primary metal to a temperature of 250°C to 600°C for at least 30 minutes in an inert environment to form a glass article comprising: (i) a glass substrate; (ii) an oxide of a first metal covalently bonded to the glass substrate; and (iii) a new metal region comprising a catalytic metal, a first metal in elemental form, a second metal in elemental form, and a primary metal in elemental form.

[0012] According to the fourth aspect of this disclosure, or any one of the first to third aspects, the catalytic metal includes one or more of the following: silver, gold, cobalt, cobalt phosphorus, nickel, or nickel phosphorus, palladium, and platinum.

[0013] According to a fifth aspect of this disclosure, or any one of the first to fourth aspects, forming a first layer of catalytic metal on a surface comprises: contacting the surface with a suspension comprising nanoparticles of catalytic metal dispersed in a liquid carrier; and evaporating the liquid carrier.

[0014] According to the sixth and fifth aspects of this disclosure, contacting the surface with the suspension includes spin-coating the suspension onto the surface.

[0015] According to the seventh aspect of this disclosure, or any one of the first to sixth aspects, the glass substrate includes a first surface and a second surface as the main surface of the glass substrate, and a sidewall surface defining a through hole, the through hole opening at the first surface and the second surface and extending through the glass substrate; and an oxide of the first metal is covalently bonded to the sidewall surface of the through hole.

[0016] According to the eighth aspect, third aspect of this disclosure, the glass substrate includes a first surface and a second surface as the main surfaces of the glass substrate, and a sidewall surface defining a through hole, the through hole opening at the first surface and the second surface and extending through the glass substrate; an oxide of a first metal is covalently bonded to the sidewall surface of the through hole; and a new metal region forms a conductive path through the through hole.

[0017] According to the ninth aspect of this disclosure, or any one of the first to sixth aspects, the glass substrate includes a first surface and a second surface as the main surface of the glass substrate, and a sidewall surface defining a blind hole, the blind hole opening at one of the first surface or the second surface and extending partially through the glass substrate; and an oxide of the first metal is covalently bonded to the sidewall surface of the blind hole.

[0018] According to the tenth aspect of this disclosure, or any one of the first to ninth aspects, the first metal of the second layer includes one or more of the following: tantalum, niobium, aluminum, manganese, rhenium, hafnium, chromium, zirconium, titanium, indium, tungsten, magnesium, molybdenum, nickel, and zinc; and the second metal of the second layer includes one or more of the following: silver, palladium, and copper.

[0019] According to the eleventh aspect of this disclosure, or any one of the first to tenth aspects, wherein the oxide of the first metal does not contain the second metal.

[0020] According to the twelfth aspect of this disclosure, or any one of the first to tenth aspects, the second metal of the second layer is copper.

[0021] According to aspect thirteen of this disclosure, or any one of aspects one through twelfth, the first metal of the second layer is manganese or zinc.

[0022] According to the fourteenth aspect of this disclosure, or any one of the first to thirteenth aspects, the oxide of the first metal of the alloy has an enthalpy of formation, the absolute value of which is greater than 600 kJ per mole; and the oxide of the second metal of the alloy has an enthalpy of formation, the absolute value of which is less than 600 kJ per mole.

[0023] According to the fifteenth aspect of this disclosure, or any one of the first to fourteenth aspects, the step of forming a second layer of the alloy includes electroless plating of a second layer on the first layer using a solution comprising a salt of a first metal dissolved in the solution and a salt of a second metal dissolved in the solution.

[0024] According to the sixteenth and fifteenth aspects of this disclosure, the solution further comprises formaldehyde and has a pH greater than 11.

[0025] According to the seventeenth and fifteenth aspects of this disclosure, the solution further comprises dimethylamine borane and has a pH of 6 to 8.

[0026] According to the eighteenth aspect of this disclosure, or any one of the first to seventeenth aspects, subjecting a glass substrate having a second layer of an alloy of a first metal and a second metal on a first layer of catalytic metal to a temperature of 250°C to 600°C includes increasing the temperature at a rate of 1°C or less per minute.

[0027] According to the nineteenth aspect of this disclosure, or any one of the first to eighteenth aspects, the step of subjecting a glass substrate having a second layer of an alloy of a first metal and a second metal on a first layer of catalytic metal to a temperature of 250°C to 600°C is performed with the glass substrate in the presence of air; and the method further includes: subjecting a glass article to a temperature of 375°C to 425°C, and then subjecting the glass article to a temperature of 225°C to 275°C for at least 30 minutes in the presence of a forming gas.

[0028] According to the twentieth aspect of this disclosure, the second aspect, the principal metals include one or more of the following: silver, gold, cadmium, chromium, copper, nickel, lead, platinum and tin.

[0029] According to aspect 21 of this disclosure, the second aspect, the principal metals include one or more of the following: silver, gold, cadmium, chromium, copper, nickel, lead, platinum and tin.

[0030] According to any one of the twenty-second, twenty-third, and twenty-first aspects of this disclosure, the third layer has a thickness of 2 µm to 5 µm.

[0031] According to aspect 23, the second, and any of aspects 20 to 22 of this disclosure, forming a third layer of primary metal on a metal region of a glass article includes electroplating the third layer of primary metal onto the metal region of the glass article.

[0032] According to aspects 24 and 23 of this disclosure, electroplating utilizes an electroplating solution comprising copper sulfate.

[0033] According to the twenty-fifth aspect of this disclosure, and any one of the first to twenty-fourth aspects, the step of subjecting a glass substrate having a first layer of catalytic metal to a temperature of 150°C to 600°C for at least 2 minutes includes: subjecting the glass substrate having a first layer of catalytic metal to a temperature of 325°C to 375°C for at least 2 minutes; and the step of subjecting a glass substrate having a second layer of an alloy of a first metal and a second metal on the first layer of catalytic metal to a temperature of 250°C to 600°C for at least 30 minutes includes: subjecting the glass substrate having a second layer of an alloy of a first metal and a second metal on the first layer of catalytic metal to a temperature of 300°C to 425°C for at least 30 minutes.

[0034] According to the twenty-sixth aspect, the third aspect of this disclosure, the step of subjecting a glass substrate having a first layer of catalytic metal to a temperature of 150°C to 600°C for at least 2 minutes includes: subjecting the glass substrate having a first layer of catalytic metal to a temperature of 325°C to 375°C for at least 2 minutes; the step of subjecting a glass substrate having a second layer of an alloy of a first metal and a second metal on the first layer of catalytic metal to a temperature of 250°C to 600°C for at least 30 minutes includes: subjecting the glass substrate having a second layer of an alloy of a first metal and a second metal on the first layer of catalytic metal to a temperature of 300°C to 425°C for at least 30 minutes; and the step of subjecting a glass article having a third layer of a main metal to a temperature of 250°C to 600°C for at least 30 minutes in an inert environment includes: subjecting the glass article having a third layer of a main metal to a temperature of 300°C to 400°C in an inert environment for at least 30 minutes.

[0035] According to aspect 27, 3 or 26 of this disclosure, an inert environment is a decompression environment.

[0036] According to the twenty-eighth aspect of this disclosure, the glass insert includes: a glass substrate including a first surface and a second surface as principal surfaces of the glass substrate and a through hole extending from the first surface through the thickness of the glass substrate to the second surface, the through hole having sidewall surfaces and a central axis; a metal region disposed inside the through hole around the central axis; and an oxide of a first metal covalently bonded to the sidewall surface of the through hole, the oxide of the first metal being disposed between the sidewall surface and the metal region, the metal region comprising a first metal in elemental form and a second metal in elemental form.

[0037] According to aspects 29 and 28 of this disclosure, the first metal includes one or more of the following: tantalum, niobium, aluminum, manganese, rhenium, hafnium, chromium, zirconium, titanium, indium, tungsten, magnesium, molybdenum, nickel, and zinc; and the second metal includes one or more of the following: silver, palladium, and copper.

[0038] According to the thirtieth and twenty-eighth aspects of this disclosure, the oxide of the first metal has an enthalpy of formation, the absolute value of which is greater than 325 kJ per mole; and the oxide of the second metal has an enthalpy of formation, the absolute value of which is less than 175 kJ per mole.

[0039] According to aspects thirty-one and twenty-eight of this disclosure, the first metal is manganese and the second metal is copper.

[0040] According to aspect thirty-two, or any one of aspects twenty-eight to thirty-one of this disclosure, wherein the metallic region further includes silver.

[0041] Additional features and advantages will be set forth in the detailed description below, and such description will be apparent to those skilled in the art, or appreciated by practicing the embodiments described herein, including the detailed description and claims.

[0042] It should be understood that the above overview and the following details are examples, and are intended to provide a summary or framework to understand the nature and characteristics of the claims. Attached Figure Description

[0043] Figure 1 A perspective view of a glass substrate used as an insert shows a through hole extending from a first surface through the thickness of the glass substrate to a second surface.

[0044] Figure 2 To intercept Figure 1 Line II-II Figure 1 A cross-sectional view of a glass substrate shows each of the through holes having a central axis perpendicular to the first and second surfaces, and the through holes defined by the sidewall surfaces.

[0045] Figure 3 A flowchart of a method for manufacturing a glass article, such as an insert, showing the various steps of forming a metal layer and heat-treating these metal layers;

[0046] Figure 4 In order to be in Figure 3 After the steps of the method, extract Figure 1 Line IV-IV Figure 1 A cross-sectional view of a glass substrate, showing the formation of a first layer of catalytic metal on the surface of the through-hole sidewall;

[0047] Figure 5 In order to be in Figure 3 The other steps of the method follow, but with Figure 4 The same figure shows a second layer of an alloy of a first metal and a second metal formed on a first layer of catalytic metal;

[0048] Figure 6 In order to be in Figure 3 Another step of the method, but with Figure 5 The same figure shows an oxide of the first metal formed from a second layer bonded to the sidewall surface of the glass substrate, and a metal region comprising a first metal, a second metal, and a catalytic metal, all in elemental form, disposed above the oxide of the first metal;

[0049] Figure 7 In order to be in Figure 3 Another step of the method, but with Figure 6The same figure shows a third layer of the main metal deposited over the metal area to fill the remainder of the through-hole, thus fully metallizing the through-hole;

[0050] Figure 8 In order to be in Figure 3 Another step of the method, but with Figure 7 The same figure shows the formation of a new metal region and an oxide of a first metal, the new metal region comprising a first metal, a second metal, a catalytic metal, and a main metal, all in elemental form, the oxide of the first metal disposed between the sidewall surface and the new metal region, and bonded to the sidewall surface and the new metal region;

[0051] Figure 9 According to Figure 3 The photographs of the tape pull test results on the sample glass articles manufactured by the method show that the tape did not pull out many new metal areas from the first surface of the glass substrate, thus implying high adhesion;

[0052] Figure 10 According to Figure 3 A photograph of the tape pull test results of another sample glass article manufactured by the method shows that the tape did not pull out many new metal areas from the first surface of the glass substrate, thus implying high adhesion.

[0053] Figure 11 According to Figure 3 A photograph of the tape pull test results of another sample glass article manufactured by the method shows that the tape did not pull out many new metal areas from the first surface of the glass substrate, thus implying high adhesion.

[0054] Figure 12 Unfounded Figure 3 A photograph of the tape pull test results of a sample glass article manufactured by the method shows that the tape pulls out a significant amount of deposited metal from the first surface of the glass substrate, thus suggesting low adhesion; and

[0055] Figure 13 Unfounded Figure 3 A photograph of the tape pull test results of another sample glass article manufactured by the method shows that the tape pulled a lot of deposited metal from the first surface of the glass substrate, thus suggesting low adhesion. Detailed Implementation

[0056] The preferred embodiments of this invention will now be described in detail, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numerals will be used throughout the drawings to denote the same or similar parts.

[0057] glass substrate

[0058] Now refer to Figure 1 and Figure 2 The image shows a glass substrate 100 in the form of an insert. The glass substrate 100 includes a first surface 102 and a second surface 104. In an embodiment, the first surface 102 and the second surface 104 are the main surfaces of the glass substrate 100, are at least approximately parallel, and generally face opposite directions.

[0059] In one embodiment, the glass substrate 100 is an alkaline earth metal aluminum borosilicate glass substrate, an alkali metal aluminum borosilicate glass substrate, an alkali metal aluminum borosilicate glass substrate, or fused silica (including high-purity fused silica). In other embodiments, the glass substrate 100 is alkali-free, such as an alkali-free aluminum borosilicate glass substrate or an alkali-free aluminum borosilicate glass substrate. "Alkali-free" means that the glass substrate 100 does not contain a target amount of alkali metal, such that any alkali metal in the glass substrate 100 exists as an impurity. In one embodiment, the glass substrate 100 has a composition comprising (molar percentage based on oxides): SiO2 – 60 to 78; Al2O3 – 6 to 15.

[0060] For example, in some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 64.0 to 71.0 – SiO2; 9.0 to 12.0 – Al2O3; 7.0 to 12.0 – B2O3; 1.0 to 3.0 – MgO; 6.0 to 11.5 – CaO; 0 to 2.0 – SrO; 0 to 0.1 – BaO; and at least 0.01 – SnO2; wherein 1.00 ≦ Σ[RO] / [Al2O3] ≦ 1.25, where [Al2O3] is the molar percentage of Al2O3, and Σ[RO] is equal to the sum of the molar percentages of MgO, CaO, SrO, and BaO. In such embodiments, the glass substrate 100 may have a 20 x 10⁻⁶ ohm diameter at room temperature. -7 / °C to 50x10 -7 / °C, for example 28x10 -7 / °C to 34x10 -7 / °C, for example, about 31.7 x 10 -7 The coefficient of thermal expansion (CTE) per °C. Terms such as "CTE," "coefficient of thermal expansion," etc., refer to how the dimensions of an article change with temperature. The CTE measures the fraction of a dimension change per degree of temperature change at constant pressure; dimensions can refer to volume, area, or linear quantities.

[0061] In some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 61 to 75 – SiO2; 7 to 15 – Al2O3; 0 to 12 – B2O3; 9 to 21 – Na2O; 0 to 4 – K2O; 0 to 7 – MgO; and 0 to 3 – CaO.

[0062] In some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 60 to 70 – SiO2; 6 to 14 – Al2O3; 0 to 15 – B2O3; 0 to 15 – Li2O; 0 to 20 – Na2O; 0 to 10 – K2O; 0 to 8 – MgO; 0 to 10 – CaO; 0 to 5 – ZrO2; 0 to 1 – SnO2; 0 to 1 – CeO2; less than 50 ppm As2O3; and less than 50 ppm Sb2O3; wherein 12 mol% ≦ Li2O + Na2O + K2O ≦ 20 mol%; and 0 mol% ≦ MgO + CaO ≦ 10 mol%.

[0063] In some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 64 to 68 – SiO2; 12 to 16 – Na2O; 8 to 12 – Al2O3; 0 to 3 – B2O3; 2 to 5 – K2O; 4 to 6 – MgO; and 0 to 5 – CaO, wherein: 66 mol% ≦ SiO2 + B2O3 + CaO ≦ 69 mol%; Na2O + K2O + B2O3 + MgO + CaO + SrO > 10 mol%; 5 mol% ≦ MgO + CaO + SrO ≦ 8 mol%; (Na2O + B2O3) – Al2O3 ≦ 2 mol%; 2 mol% ≦ Na2O – Al2O3 ≦ 6 mol%; and 4 mol% ≦ (Na2O + K2O) – Al2O3 ≦ 10 mol%.

[0064] In some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 66 to 78–SiO2; 4 to 11–Al2O3; 4 to 11–B2O3; 0 to 2–Li2O; 4 to 12–Na2O; 0 to 2–K2O; 0 to 2–ZnO; 0 to 5–MgO; 0 to 2–CaO; 0 to 5–SrO; 0 to 2–BaO; and 0 to 2–SnO2.

[0065] In some embodiments, the glass substrate 100 comprises (in molar percentages based on oxides): 69.49–SiO2; 8.45–Al2O3; 14.01–Na2O; 1.16–K2O; 0.185–SnO2; 0.507–CaO; 6.2–MgO; 0.01–ZrO2; and 0.008–Fe2O3.

[0066] In one embodiment, the glass substrate 100 is fabricated using a glass manufacturing system employing a melting process to produce a glass sheet, which is then cut into the desired shape for the glass substrate 100. The melting process forms a glass substrate 100 with a uniform thickness, for example, having a total thickness variation (TTV) of less than 1.0 µm. Therefore, grinding or other finishing steps are not required before using the glass substrate 100 as an insert. If the melting process produces a glass sheet that is thicker than the required thickness 106 of the glass substrate 100, the thickness 106 of the glass substrate 100 can be thinned by known means such as etching or grinding. In other embodiments, the glass substrate 100 is fabricated using a non-melting process and then ground or etched to have the desired thickness 106. After the glass substrate 100 is fabricated, it can be annealed to reduce residual stress present in the glass substrate 100.

[0067] In the illustrative embodiments, the thickness 106 of the glass substrate 100 extends from the first surface 102 and the second surface 104. In these embodiments, while larger or smaller values ​​for the thickness 106 are anticipated, the thickness 106 ranges from about 25 µm to about 1 mm. For example, for the embodiments described herein, the thickness 106 of the glass substrate 100 is about 50 µm, about 100 µm, about 200 µm, about 300 µm, about 400 µm, about 500 µm, about 600 µm, about 700 µm, about 800 µm, about 900 µm, about 1 mm, and any range using these values, such as in the range of 50 µm to 300 µm, etc. In these embodiments, the thickness 106 is in the range of 50 µm to 100 µm. The glass substrate 100 may have any desired shape. In these embodiments, the glass substrate 100 is circular. In these embodiments, the glass substrate 100 may have a diameter in the range of 200 mm to 300 mm. In other embodiments, the glass substrate 100 has a square or rectangular shape.

[0068] The glass substrate 100 further includes one or more through holes 108. In one embodiment, the glass substrate 100 includes a plurality of through holes 108. In one embodiment, some or all of the one or more through holes 108 extend from the first surface 102 through the thickness 106 of the glass substrate 100 to the second surface 104. Such through holes 108 herein may refer to “through-holes”. The through holes 108 open at both the first surface 102 and the second surface 104. In other embodiments, some or all of the one or more through holes 108 open to the first surface 102 but only partially extend through the thickness 106, not extending all the way through the thickness 106 to the second surface 104. Such through holes 108 herein may refer to “blind holes”. In one embodiment, the glass substrate 100 includes both a plurality of through holes 108 and blind holes 108. The sidewall surface 110 defines each through hole 108 within the thickness 106 of the glass substrate 100.

[0069] The through-hole 108 has a diameter 112. Although the diameter 112 of each through-hole 108 is shown to be the same, this is not necessary, meaning that the diameter 112 of the through-hole 108 is variable within the same glass substrate 100. In embodiments, the diameter 112 is in the range of 5 micrometers to 150 micrometers. In embodiments, such as the one shown, the through-hole 108 has an hourglass shape with a waist 114, where the diameter 112 of the through-hole 108 at the waist 114 is smaller than the diameter 112 of the through-hole 108 at the first surface 102 and / or the second surface 104 of the glass substrate 100. The hourglass shape is advantageous for electroplating, as further explained below. In other embodiments, the through-hole 108 has a substantially cylindrical or substantially conical shape.

[0070] Each through-hole 108 has a central axis 116. The central axis 116 of one through-hole 108 is spaced apart from the central axis 116 of adjacent through-holes 108 by a spacing 118. Depending on the desired application, the spacing 118 can be any value, for example, not by limitation, from about 10 µm to about 2000 µm, including about 10 µm, about 25 µm, about 50 µm, about 100 µm, about 250 µm, about 500 µm, about 1000 µm, about 2000 µm, or any value or range between any two of these values ​​(including endpoints). For example, the spacing 118 can be in the following ranges: 10 µm to 100 µm; 25 µm to 500 µm; 10 µm to 1000 µm; or 250 µm to 2000 µm. The spacing 118 on the same glass substrate 100 can be variable or constant. For example, depending on the design and application of the insert, the spacing 118 may have 1 to 20 through holes 108 per square millimeter. In one embodiment, the through holes 108 are patterned throughout the entire glass substrate 100. In other embodiments, the through holes 108 are not patterned.

[0071] Through-hole 108 is formed within glass substrate 100 using one of various forming techniques. For example, through-hole 108 can be formed by mechanical drilling, etching, laser ablation, laser-assisted processing, laser destruction and etching processes, sandblasting, abrasive waterjet processing, concentrated electron thermal energy, or any other suitable forming technique. In a laser destruction and etching process, a destruction path is initially formed in glass substrate 100 using a laser to modify glass substrate 100 along the destruction path. An etching solution is then applied to glass substrate 100. The glass substrate 100 is thinned by the etching solution. Because the etching rate of glass substrate 100 is faster at the destruction path, the destruction path is preferentially etched, thus creating an opening 108 through glass substrate 100.

[0072] Method 200 for metallized glass substrate 100, for example, through-hole 108

[0073] Please refer to now. Figures 3-6 According to the novel method 200 described herein, the through-hole 108 of the glass substrate 100 is metallized. While method 200 describes the glass substrate 100 as an insert and aims to metallize the through-hole 108, it should be understood that method 200 relates to placing metal on the glass substrate 100 for any purpose, and to metallizing surfaces other than the sidewall surface 110 of the through-hole 108, such as the first surface 102, the second surface 104, and / or other holes in the glass substrate 100. In the context of the glass substrate 100 as an insert, as mentioned in the prior art, the metallized through-hole 108 provides a conductive path for electrical signals to travel from the first surface 102 to the second surface 104 through the insert.

[0074] A first layer 120 of catalytic metal is formed. In step 202, method 200 includes forming a first layer 120 of catalytic metal on the surface of glass substrate 100 (see specific reference). Figure 4In one embodiment, the first layer 120 of the catalytic metal may cover all or substantially all of the glass substrate 100. In one embodiment, such as an illustrative embodiment, step 202 includes forming the first layer 120 of the catalytic metal on the sidewall surface 110 of the through-hole 108 of the glass substrate 100. In other embodiments, step 202 includes forming the first layer 120 of the catalytic metal on the first surface 102 or the second surface 104, or on both the first surface 102 and the second surface 104. Alternatively, the first layer 120 of the catalytic metal may be patterned to cover a portion of the glass substrate 100, such as a portion of the first surface 102, a portion of the second surface 104, a portion or all of the sidewall surface 110 of the through-hole 108, or some combination thereof. Patterning may be accomplished by selectively masking areas of the glass substrate 100 during the deposition of the first layer 120 of the catalytic metal on the glass substrate 100, for example with blocking tape or photoresist.

[0075] The catalytic metal acts as a catalyst, promoting the deposition of subsequent metal layers on top of the catalytic metal via electroless deposition or other methods. In embodiments, the catalytic metal includes one or more of the following: silver, gold, cobalt, cobalt phosphorus, nickel, nickel phosphorus, palladium, and platinum. In embodiments, the catalytic metal is silver or palladium, or is substantially composed of silver or palladium. In embodiments, the first layer 120 of the catalytic metal is a nanolayer with a thickness 122 in the range of 5 nm to approximately 10,000 nm, for example, in the range of 5 nm to 100 nm.

[0076] In an embodiment, the first layer 120 of the catalytic metal is silver or is substantially composed of silver, and step 202 of method 200 includes forming the first layer 120 of silver as the catalytic metal on the sidewall surface 110 of the through hole 108 of the glass substrate 100.

[0077] In an embodiment, the step of forming a first layer 120 of catalytic metal on the sidewall surface 110 of the through-hole 108 of the glass substrate 100 (or any other desired surface of the glass substrate 100) includes: (i) contacting the sidewall surface 110 of the glass substrate 100 with a suspension of nanoparticles of catalytic metal dispersed in a liquid carrier; and (ii) evaporating the liquid carrier. The liquid carrier may be water-based or solvent-based. Solvent-based liquid carriers may be single solvents, solvent mixtures, or solvents having other non-solvent components (single solvents or solvent mixtures). Examples of usable solvents include, but are not limited to, hydrocarbons, halogenated hydrocarbons, alcohols, ethers, ketones, etc., or mixtures thereof, such as 2-propanol (also known as isopropanol, IPA, or isopropyl alcohol), tetrahydrofuran (THF), ethanol, chloroform, acetone, butanol, octanol, pentane, hexane, heptane, cyclohexane, and mixtures thereof. Example suspensions are nanoparticles of a catalytic metal in cyclohexane at concentrations ranging from 10% (w / v)% to 30% (w / v). The catalytic metal nanoparticles are left on the sidewall surface 110 of the through-hole 108 of the glass substrate 100 after the liquid carrier evaporates.

[0078] The term "nanoparticle" refers to a particle / component having an average diameter (or cross-sectional size) along its shortest axis between about 1 nm and about 10,000 nm. It should be understood that the particle size of a nanoparticle can be a distribution characteristic. Furthermore, in some embodiments, nanoparticles may have different sizes or distributions or more than one size or distribution. Therefore, particle size can refer to the average particle diameter associated with an individual particle size distribution. In some embodiments, the nanoparticles have wavelengths ranging from about 5 nm to about 10000 nm, from about 5 nm to about 7500 nm, from about 5 nm to about 5000 nm, from about 5 nm to about 2500 nm, from about 5 nm to about 2000 nm, from about 5 nm to about 1500 nm, from about 5 nm to about 1250 nm, from about 5 nm to about 1000 nm, from about 5 nm to about 750 nm, from about 5 nm to about 500 nm, from about 5 nm to about 250 nm, from about 5 nm to about 200 nm, from about 5 nm to about 150 nm, from about 5 nm to about 125 nm, from about 5 nm to about 100 nm, from about 5 nm to about 75 nm, from about 5 nm to about 50 nm, from about 5 nm to about 25 nm, and from about 5 nm to about 20 nm, as well as from 8 nm to 15 nm, such as about 5 nm, 10 nm, 20 nm, 25 nm, 50 nm, 75 nm, 100 nm, 125 nm. The average diameter can be 150 nm, 175 nm, 200 nm, 250 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 750 nm, 800 nm, 900 nm, 1000 nm, 1250 nm, 1500 nm, 2000 nm, 2500 nm, 5000 nm, 7500 nm, or 10000 nm. Nanoparticle sizes can be measured using methods such as dynamic light scattering techniques or transmission electron microscopy (TEM). For example, as is known in the art, particle size distribution is often calculated through TEM image analysis of samples composed of hundreds of different nanoparticles.

[0079] Nanoparticles can have any shape and surface features. The structure and geometry of nanoparticles can be varied, and this disclosure is not intended to limit any particular geometry and / or structure. Embodiments herein include multiple nanoparticles, and individual nanoparticles or groups of nanoparticles may have the same or different structures and / or geometries as other nanoparticles. For example, in some embodiments, nanoparticles may be spherical, elongated elliptical, polyhedral, plate-like, or have a crystalline structure. In some embodiments, the surface of the nanoparticles may be smooth, rough, regular, irregular, or patterned.

[0080] In some embodiments, the metal nanoparticles are silver nanoparticles. In some embodiments, the silver nanoparticles have an average diameter of 10 nm to 13 nm and are dispersed in cyclohexane (purchased from Cerion Ltd., Rochester, NY, USA) at a concentration of 20 percent (w / v).

[0081] Optionally, the suspension of nanoparticles can be ultrasonically treated before the glass substrate 100 is brought into contact with the suspension of nanoparticles to promote dispersion of the nanoparticles throughout the liquid carrier. For example, the suspension of nanoparticles can be ultrasonically treated for a period of time ranging from 15 to 45 minutes, such as about 30 minutes.

[0082] As mentioned, the first layer 120 of the catalytic metal is a nanolayer having a thickness in the range of 5 nm to about 10,000 nm, for example, in the range of 5 nm to 100 nm. The first layer 120 may include less than a single layer, a single layer, or multiple single layers of nanoparticles. In an embodiment, the first layer 120 of the catalytic metal is not uniform, but rather consists of single particles or clusters of particles on the sidewall surface 110 (or, as appropriate, a first surface 102, a second surface 104) of the through-hole 108 of the glass substrate 100, accompanied by the remaining exposed portion of the sidewall surface 110.

[0083] In an embodiment, the step of contacting the desired surface of the glass substrate 100 (e.g., first surface 102, second surface 104, sidewall surface 110) with the suspension of catalytic metal nanoparticles includes spin-coating the suspension onto the surface of the glass substrate 100. Spin-coating can be performed at any speed and for any time period sufficient to form the desired nanoparticle layer of catalytic metal nanoparticles on the glass substrate 100. For example, the nanoparticle suspension can be deposited on the glass substrate 100 rotating at 1000 to 5000 rpm (e.g., 1000, 2000, 3000, 4000, or 5000 rpm) for a period of about 30 seconds, or less, or more than 30 seconds.

[0084] In an embodiment, the step of contacting a desired surface of the glass substrate 100 (e.g., first surface 102, second surface 104, sidewall surface 110) with a suspension of catalytic metal nanoparticles includes immersing the desired surface of the glass substrate 100 into the nanoparticle suspension or spraying the surface of the glass substrate 100 with the nanoparticle suspension. The immersion coating can be performed at a pull-out rate (sometimes referred to as the pull rate) (e.g., 30 mm to 35 mm per minute) suitable for forming the first layer 120 of the catalytic metal on the surface of the glass substrate 100.

[0085] This type of solution-based process for forming a first layer 120 of catalytic metal on the surface of the glass substrate 100 (e.g., the first surface 102, the second surface 104, and the sidewall surface 110) is an improvement over non-solution-based processes such as vacuum deposition. The aforementioned suspension and dip-coating solution-based processes are less expensive than vacuum deposition. Furthermore, as the aspect ratio of the through-hole 108 increases, these solution-based processes can form the first layer 120 of catalytic metal on the sidewall surface 110 of the through-hole 108; however, vacuum deposition is unlikely to completely cover the sidewall surface 110 of the through-hole 108 with the first layer 120.

[0086] The glass substrate 100 having a first layer 120 of catalytic metal is heat-treated. In step 204, method 200 further includes subjecting the glass substrate 100 having the first layer 120 of catalytic metal to a temperature of 150°C to 600°C for a period of at least 2 minutes. In embodiments, the temperature is 250°C to 400°C, for example, about 325°C to 375°C, for example, about 350°C or 350°C. In embodiments, the time period is 2 to 5 minutes. Step 204 herein may refer to “heat-treating” the glass substrate 100 having the deposited first layer 120 of catalytic metal. If the first layer 120 of catalytic metal is susceptible to oxidation, step 204 may then be performed in an inert atmosphere (e.g., a nitrogen atmosphere), or if it is not susceptible to oxidation, subsequent heat treatment in a reducing atmosphere (e.g., a hydrogen atmosphere) may be performed to reduce the oxidized catalytic metal back to its elemental form. The oxidized first layer 120 of catalytic metal inhibits the subsequent application of a second metal layer in method 200 (discussed below). In embodiments where the first catalytic metal layer 120 is silver, silver is not easily oxidized in the presence of air during the heat treatment step 204 of method 200. In one embodiment, the glass substrate 100 is brought to room temperature and then heated at a specific ramp rate (e.g., a ramp rate in the range of 0.5°C to 10°C per minute). In other embodiments, the glass substrate 100 having the first catalytic metal layer 120 is placed directly into a preheating furnace set to a predetermined temperature within the operating range of step 204. Step 204 can be performed by placing the glass substrate 100 having the first catalytic metal layer 120 into a vertical furnace, a tube furnace, a rapid thermal annealing (RTA) furnace, on a hot plate, etc. In embodiments using palladium as the catalytic metal layer 120, step 204 can be omitted – that is, method 200 need not include step 204.

[0087] A second alloy layer 124 is formed on the first layer 120. In step 206, method 200 further includes forming a second alloy layer 124 of the first metal and the second metal on the first layer 120. In embodiments where the first layer 120 is not uniform and the remaining exposed portion of the sidewall surface 110 is present, the second alloy layer 124 of the first metal and the second metal is formed on the first layer 120 and the exposed sidewall surface 110. In embodiments, such as the illustrative embodiment where the first layer 120 is formed on the sidewall surface 110, the formed second layer 124 is closer to the central axis 116 than the first layer 120 but does not close the through-hole 108. Step 206 occurs after the heat treatment step 204. The first metal has a greater tendency to form oxides than the second metal, which form covalent bonds with desired surfaces of the glass substrate 100 (e.g., the sidewall surface 110 of the through-hole 108, etc.). The enthalpy of formation of such oxides is a quantification of this tendency. In one embodiment, the absolute value of the enthalpy of formation of the first metal oxide is greater than the absolute value of the enthalpy of formation of the second metal oxide. In another embodiment, the absolute value of the enthalpy of formation of the first metal oxide is greater than 600 kJ per mole, while the absolute value of the enthalpy of formation of the second metal oxide is less than 600 kJ per mole. In yet another embodiment, the absolute value of the enthalpy of formation of the first metal oxide is greater than 325 kJ per mole, while the absolute value of the enthalpy of formation of the second metal oxide is less than 175 kJ per mole. In yet another embodiment, the absolute value of the enthalpy of formation of the first metal oxide is greater than 900 kJ per mole, while the absolute value of the enthalpy of formation of the second metal oxide is less than 175 kJ per mole. In yet another embodiment, the first metal of the second layer 124 includes one or more of the following: tantalum, niobium, aluminum, manganese, rhenium, hafnium, chromium, zirconium, titanium, indium, tungsten, magnesium, molybdenum, nickel, and zinc; and the second metal of the second layer 124 includes one or more of the following: silver, palladium, and copper. In this embodiment, the first metal of the second layer 124 is manganese or zinc; and the second metal of the second layer 124 is copper. Table 1 below lists the enthalpy of formation of various oxides of various metals.

[0088]

[0089] In one embodiment, step 206 of forming a second layer 124 of an alloy of a first metal and a second metal on the first layer 120 includes electrolessly electroplating the second layer 124 onto the first layer 120 using a solution comprising (i) a salt of the first metal dissolved in the solution and (ii) a salt of the second metal dissolved in the solution. In the electroless electroplating, an ionic compound of anions with first metal cations and an ionic compound of anions with second metal cations are reduced to the elemental forms of the first and second metals by a chemical reducing agent. A typical electroless electroplating process requires: (a) an electroplating solution comprising ionic compounds of first and second metal cations; (b) a reducing agent; (c) a pH adjuster; (d) a miscible agent to dissolve the ionic compounds; and (e) special additives to control solution stability and electroplating rate. These solutions are deposited on a glass article having a catalytically active surface provided by a catalytic metal first layer 120. This catalytically active surface catalyzes the reduction of metal cations in ionic compounds, and simultaneously deposits the first and second metals in elemental form onto the first layer 120 of the glass article (e.g., within the perforation 108), thus forming an alloy of the first and second metals as the second layer 124. The second layer 124 is autocatalytic, thus catalyzing further reactions and deposition of additional elemental forms of the first and second metals on the second layer 124, thereby increasing its thickness.

[0090] As mentioned, electroless plating processes include plating solutions containing ionic compounds of a first metal and a second metal dissolved in a solvent. Suitable ionic compounds include nitrates, sulfates, chlorides, acetates, and cyanides of the first and second metals. Example plating solutions include manganese sulfate monohydrate as the first metal ionic compound and copper sulfate pentahydrate as the second metal ionic compound. Another example plating solution includes zinc chloride as the first metal ionic compound and copper sulfate pentahydrate as the second metal ionic compound. Typically, the ionic compounds are present in the solution at concentrations ranging from about 0.001 mM to about 25 mM. In embodiments, the ratio of the concentration of the first metal ionic compound to the concentration of the second metal ionic compound is in the range of 1:20000 to 1:1, for example, 1:20 to 1:3, including about 1:4 or 1:4. The solvent may be aqueous, or may be an organic liquid suitable for the ionic compounds. For example, such organic liquids may include alcohols, ethers, ketones, alkanes, etc.

[0091] As mentioned, the electroless plating process includes a reducing agent, a pH adjuster, and a misalignment agent. The reducing agent reduces metal cations present on the first layer 120 of the glass substrate 100. Specific examples of reducing agents include NaBH4, KBH4, NaH2PO2, hydrazine, formalin, formaldehyde, dimethylamine borane (“DMAB”), and polysaccharides (e.g., glucose). The pH adjuster adjusts the pH of the plating solution and can be an acidic or basic compound. In embodiments using formaldehyde as a reducing agent, the pH of the solution can be adjusted to 11 or greater using a pH adjuster. In embodiments using DMAB as a reducing agent, the pH of the solution can be adjusted to approximately neutral (pH about 7, for example, 6 to 8) using a pH adjuster.

[0092] Chelating agents help prevent the precipitation of hydroxides in alkaline solutions and control the concentration of cations in the first and second metals, thereby preventing the decomposition of ionic compounds and regulating the electroplating rate. Specific examples of chelating agents include ammonia solutions, acetic acid, guanylic acid, tartaric acid, chelating agents (such as ethylenediaminetetraacetic acid (EDTA)), Rocehelle salt (sodium potassium tartrate tetrahydrate), and organic amine compounds.

[0093] In one embodiment, the electroplating solution has a temperature in the range of 30°C to 70°C, for example, about 60°C. In another embodiment, the glass substrate 100 is subjected to an electroless electroplating process in the range of 20 seconds to 30 minutes, for example, about 20 minutes. In another embodiment, the second metal layer 124 formed by the electroless electroplating has a thickness 126 in the range of 10 nm to 100 nm, for example, about 50 nm. The second metal layer 124 should be thick enough to ensure sufficient conductivity, making it feasible to apply a subsequent third metal layer as described below.

[0094] The glass substrate 100 having a second layer 124 is heat-treated. In step 208, method 200 further includes subjecting the glass substrate 100 having a second layer 124 of an alloy of a first metal and a second metal on a first catalytic metal layer 120 to a temperature of 250°C to 600°C for at least 30 minutes. In embodiments, the temperature is 300°C to 450°C, for example 375°C to 425°C, for example about 400°C or 400°C. The heat treatment forms a glass article 128 (see...). Figure 6The glass article 128 includes: (i) a glass substrate 100; (ii) an oxide 130 of a first metal covalently bonded to the glass substrate 100; and (iii) a metal region 132 bonded to the oxide 130 of the first metal. In an embodiment, the oxide 130 of the first metal does not contain a second metal. The metal region 132 includes a catalytic metal in elemental form, the first metal in elemental form, and the second metal in elemental form. During the heat treatment of step 208, the first metal from the second layer 124 forms an oxide 130 bonded to the surface of the glass substrate 100, replacing the catalytic metal first layer 120.

[0095] In one embodiment, step 208 increases the ambient temperature near the glass substrate 100 at a rate of 5°C or less per minute, for example, 1°C or less per minute.

[0096] In one embodiment, heat treatment step 208 is performed with the glass substrate 100 in the presence of air. The presence of air facilitates the formation of oxide 130 of the first metal bonded to the sidewall surface 110 of the glass substrate 100. In this embodiment, method 200 further includes a heat treatment reduction step 210, in which the glass article 128 produced in step 208 is subjected to a temperature of 225°C to 275°C for 30 minutes (e.g., 30 to 90 minutes) in the presence of a forming gas (a mixture of H2 and N2). The reduction step 210 restores the conductivity of the metal region 132, making it feasible to subsequently apply a third metal layer over the metal region 132 as described below.

[0097] A third layer 134 of the main metal is formed on the glass article 128. In step 212, method 200 further includes forming a third layer 134 of the main metal on the metal region 132 of the glass article 128 (see...). Figure 7 The term "primary" in "primary metal" refers in a sense to the metal that is dominant in terms of the thickness of the glass article 128 – that is, the thickness 136 of the third layer 134 is greater than the thicknesses 122 and 126 of the first layer 120 and the second layer 124, respectively. In the example where the glass article 128 is an insert, the primary metal is the metal intended to perform the conductive function of the through-hole 108, and is the dominant metal within the through-hole 108 after metallization according to method 200. In an embodiment, the primary metal is copper or includes copper. In an embodiment, the primary metal is or includes one or more of the following: silver, gold, cadmium, chromium, copper, nickel, lead, platinum, and tin. In an embodiment, the thickness 136 of the primary metal third layer 134 is 2 µm or greater, for example, 2 µm to 5 µm.

[0098] In one embodiment, the step of forming a third layer 134 of a primary metal on the metal region 132 of the glass article 128 includes electroplating the third layer 134 of the primary metal onto the metal region 132 of the glass article 128. During electroplating, the glass article 128 is placed in an electroplating solution and an electric current is applied. This electroplating solution contains anions and ionic compounds having primary metal cations for forming the third layer 134. Therefore, the primary metal in elemental form is applied over the metal region 132 of the glass article 128 as the third layer 134. Anions of the ionic compounds containing the primary metal cations to be deposited include sulfate, nitrate, and chloride anions. An example anionic compound used in the electroplating solution is copper sulfate. An example electroplating solution includes copper sulfate pentahydrate (CuSO4∙5H2O), potassium pyrophosphate (K4P2O7), and citric acid in distilled water. Another example electroplating solution includes copper sulfate pentahydrate (CuSO4∙5H2O), manganese sulfate monohydrate (MnSO4∙H2O), potassium sodium tartrate tetrahydrate (Rochelle salt), and formaldehyde. In this embodiment, the concentration of the ionic compound in the electroplating solution is 0.001 M or greater. The ionic compound is soluble in a liquid medium, such as deionized water. Electrodes made of any conductive material, except for glass article 128, are also disposed in the electroplating solution. In this embodiment, the electroplating solution has a temperature between 10°C and 50°C, such as room temperature or 40°C.

[0099] A current, voltage, or a combination thereof is applied between the electrode and the glass article 128 to provide a negative constant current to the glass article 128. In one embodiment, approximately 0.001 mA / cm² is provided. 2 Approximately 1 A / cm 2 The current density range and voltage range are from approximately −0.001 V to approximately −20 V. Therefore, the main metal cation to be used as the third layer 134 is reduced to its elemental form above the metal region 132 of the glass article 128. The current density controls the rate of this reduction reaction. Therefore, the deposition rate can be increased or decreased by increasing or decreasing the applied current. However, it should be noted that excessively high applied current will cause filling of voids and gaps, and too low applied current will make the process too long and impractical. After the third layer 134 of the main metal is applied to the glass article 128 above the metal region 132, the current is stopped, the glass article 128 is removed from the electroplating solution, and the glass article 128 can be washed with deionized water. The glass article 128 can now be dried as needed, for example by blowing a nitrogen stream onto the glass article 128.

[0100] In embodiments where the glass article 128 is intended as an insert, a third layer 134 of the primary metal fills the opening left by the through-hole 108. When the third layer 134 of the primary metal is added by electroplating, the glass article 128 is placed in an electroplating solution such that the electroplating solution fills all or part of the through-hole 108. The third layer 134 of the primary metal is deposited on the metal region 132 of the glass article 128 and continuously accumulated until the through-hole 108 is sealed shut, thus completely metallizing the through-hole 108. In embodiments where the through-hole 108 is hourglass-shaped, the narrow waist 114 provides a metallic “bridge” for the conductive third layer 134 of the primary metal to be initially deposited. The third layer 134 of the primary metal is continuously deposited on both sides of this bridge until the through-hole 108 is filled. The “bridge” helps prevent the deposition of the third layer 134 of the primary metal near the first surface 102 or the second surface 104, thus preventing the opening to the interior of the through-hole 108 from closing before the through-hole 108 is filled with the third layer 134 of the primary metal. The closure of such openings into the interior of the through-hole 108 creates voids within the through-hole 108, which reduce conductivity. When the through-hole 108 is filled and fully metallized with the metal region 132 and the third layer 134 of the main metal, the through-hole 108 can electrically connect to the electrical traces of electronic components disposed on or adjacent to the first surface 102 and the second surface 104 of the glass article 128. Once the third layer 134 of the main metal fills the through-hole 108 of the glass article 128, the current stops and the plating solution is separated from the glass article 128.

[0101] The glass article 128 having a third layer 134 of a primary metal is heat-treated. In step 214, method 200 further includes subjecting the glass article 128 having the third layer 134 of a primary metal to a temperature of 250°C to 600°C, for example 300°C to 400°C, for example 325°C to 375°C, for example about 350°C or 350°C for at least 30 minutes in an inert environment (e.g., reduced pressure, nitrogen, or a forming gas environment). The heat treatment step 214 forms the glass article 128, which includes: (i) a glass substrate 100; (ii) an oxide 130 of a first metal covalently bonded to the glass substrate 100; and (iii) a new metal region 138 comprising a catalytic metal, a first metal, a second metal, and a primary metal, all in elemental form (see [link to relevant documentation]). Figure 8 In other words, heat treatment step 214 transforms the metal region 132 produced in step 208 into a new metal region 138, which further comprises the main metal in elemental form.

[0102] One objective of step 214 is to mix the metal region 132 from step 208 with the third layer 134 of the main metal added in step 212. While temperatures below 325°C can achieve this objective, such temperatures would require an impractical length of time for practical purposes. In other words, a temperature below 325°C in step 214 would result in such mixing, but could take too long to be commercially viable. Temperatures of 375°C or lower in step 214 would be compatible with most glass substrates 100. Another objective of step 214 is to alleviate stress that may have developed in the glass article 128. For example, the laser process used to form through-holes 108 in the glass substrate 100 intended as inserts can generate thermal stress within the glass substrate 100. Annealing the subsequent glass article 128 formed after the metallization of the through-holes 108 alleviates residual stress that may exist in the glass substrate 100.

[0103] In the embodiment where the glass article 128 is used as an insert, the through-hole 108 is now fully metallized, and the through-hole 108 includes an oxide 130 of a first metal covalently bonded to the sidewall surface 110 of the through-hole 108 and a new metal region 138 bonded to the oxide 130 of the first metal. Thus, the oxide 130 of the first metal is disposed between the sidewall surface 110 of the through-hole 108 and the new metal region 138. The new metal region 138 forms a conductive path through the through-hole 108. The new metal region 138 is disposed within the through-hole 108 around a central axis 116. The new metal region 138 comprises a first metal in elemental form, which is bonded to the oxide 130 of the first metal. In this embodiment, a portion of the glass substrate 100 is metallized with an oxide 130 of a first metal covalently bonded to the first surface 102 and the second surface 104, and a new metal region 138 comprising a catalytic metal, a first metal, a second metal, and a predominant metal, all in elemental form, is bonded to the oxide 130 of the first metal. It is anticipated that the new metal region 138 is substantially predominantly metal at or near the central axis 116.

[0104] The formation and incorporation of the oxide 130 of the first metal enhances the effective adhesion of the primary metal (e.g., copper) to the glass substrate 100. Therefore, the second layer 124 of the alloy of the first and second metals performs the following functions: (i) assists the subsequent application of metal by forming the oxide 130 of the first metal to adhere to the glass substrate 100; and (ii) assists in the application of the third layer 134 of the primary metal, because the second metal of the alloy second layer 124 is less prone to oxide formation and ensures that the metal region 132 generated in step 208 is sufficiently conductive to participate in the formation of the third layer 134 of the primary metal in step 212 (e.g., through-hole plating). The combination of the oxide 130 of the first metal covalently bonded to the sidewall surface 110 of the glass substrate 100 with the metal bonding and mixing of the catalytic metal, the first metal, the second metal, and the primary metal at the new metal region 138 results in strong adhesion of the primary metal to the glass substrate 100. Furthermore, all steps 202, 206, and 212 that form the first layer 120, the second layer 124, and the third layer 134 are solution-based, which enables those through-holes 108, even those with high aspect ratios, to be thoroughly metallized in a cost-effective manner without noticeable voids (e.g., pinholes).

[0105] Example

[0106] Example 1. According to step 202 of method 200, a first layer 120 of silver, serving as a catalytic metal, is formed on the first surface 102 of a glass substrate 100 sample. The glass substrate 100 of this sample, as well as all other samples described below, is an alkaline earth metal aluminum borosilicate glass substrate. More specifically, silver nanoparticles are dispersed in a liquid carrier. The nanoparticles have an average size of 10 nm to 13 nm. The liquid carrier is cyclohexane. The concentration of the silver nanoparticles is 20% (w / v) of the cyclohexane. The suspension is ultrasonically treated for 30 minutes to aid in the separation of aggregated silver nanoparticles. The suspension is then spin-coated onto the first surface 102 of the glass substrate 100 at 1000 RPM. The liquid carrier is evaporable. Next, according to step 204 of method 200, the glass substrate 100 sample having a first layer 120 of catalytic metal (silver) is subjected to 350°C for 2 minutes in an air environment, thereby forming a glass substrate 100 having a catalytic metal disposed on the first surface 102 as the first layer 120.

[0107] Next, according to step 206 of method 200, a second alloy layer 124 is formed on the catalytic metal by electroless deposition. The bath used in the electroless deposition has the composition listed in Table 2 below, having a ratio of the concentration of manganese ion compound as the first metal to the concentration of copper ion compound as the second metal of 1:4.

[0108]

[0109] The pH of the bath without electricity was adjusted to 12.5. The temperature of the bath without electricity was maintained at 60°C. The glass substrate 100 with the silver catalyst metal was immersed in the bath for 20 minutes. The glass substrate 100 was then removed from the bath, rinsed with water, and dried in a nitrogen environment. The resulting second layer 124 is an alloy of manganese as the first metal and copper as the second metal.

[0110] Next, according to step 208 of method 200, the glass substrate 100 having the alloy second layer 124 is subjected to a temperature of 400°C for 30 minutes in an air environment. The temperature is increased to 400°C at a rate of 1°C per minute. The elemental composition of the resulting glass article 128 having the metallic region 132 is determined using X-ray photoelectron spectroscopy (XPS). The results are listed in Table 3 below.

[0111]

[0112] The results confirmed that steps 202–208 did indeed produce a metallic region 132 containing manganese and copper from the non-electrostatic bath, as well as silver from spin coating. The presence of carbon may have originated from the non-electrostatic bath or from the atmosphere.

[0113] Next, according to step 212 of method 200, a third layer 134 of the main metal (copper) is applied over the metal region 132 via an electroplating process. The electroplating process utilizes a non-acidic electroplating solution of copper sulfate dissolved in deionized water. A copper plate is used as the anode. A constant current of 50 mA is applied for 1 hour to generate a third copper layer 134 with a thickness of 2.5 µm. The glass article 128 is then removed from the electroplating solution and rinsed.

[0114] Next, according to step 214 of method 200, the glass article 128 having a third layer 134 of the main metal (copper) is subjected to a temperature of 350°C for a period of 30 minutes under reduced pressure. The heating rate to 350°C is controlled at 5°C per minute.

[0115] Now refer to Figure 9According to ASTM D3359-09 (Standard Test Methods for Measuring Adhesion by Tape Test), a cross-hatch tape test was performed on the obtained glass article 128 to test the adhesion of the new metal area 138 to the glass substrate 100. For the tape test, the new metal area 138 was made into a 11-slice grid pattern in each direction. Pressure-sensitive tape 140 was then applied over the grid pattern. The tape 140 was then peeled off. The amount and type of removal were then compared with the description and illustration in the ASTM document. Less than 5% of the new metal area 138 was removed from the glass article 128 by the removal of tape 140. According to ASTM standards, the test result is 4B or 5B. This indicates that the new metal area 138, including copper, manganese, and silver, is highly adhered to the glass substrate 100.

[0116] Example 2. According to steps 202 and 204 of method 200, a first layer 120 of silver as a catalytic metal is formed on the first surface 102 of the glass substrate 100 sample in the same manner as in Example 1 and then heat-treated.

[0117] Then, according to step 206 of method 200, the second layer 124 of the alloy is formed on the catalytic metal by electroless deposition. The bath used for electroless deposition has the composition listed in Table 4 below.

[0118]

[0119] The pH of the bath without electricity was adjusted to 12.5. The temperature of the bath without electricity was maintained at 60°C. The glass substrate 100 with the silver catalytic metal was immersed in the bath for 20 minutes. The glass substrate 100 was then removed from the bath, rinsed with water, and dried in a nitrogen environment. The resulting second layer 124 is an alloy of zinc as the first metal and copper as the second metal.

[0120] Next, according to step 208 of method 200, the glass substrate 100 having the alloy second layer 124 is subjected to a temperature of 400°C for 30 minutes in an air environment. The temperature is increased to 400°C at a rate of 1°C per minute. X-ray photoelectron spectroscopy (XPS) is used to determine the elemental composition of the metal region 132 after heat treatment step 208. The results are listed in Table 5 below.

[0121]

[0122] The results confirmed that steps 202–208 did indeed produce a metallic region 132 consisting of zinc and copper from a non-electrostatic bath and silver from spin coating.

[0123] Next, according to steps 212 and 214 of method 200, a third layer 134 of the main metal (copper) is applied over the metal region 132 via an electroplating process in the same manner as in Example 1, followed by heat treatment.

[0124] Now refer to Figure 10 According to ASTM D3359-09, a cross-hatching tape test was performed on the resulting glass article 128 to test the adhesion of the resulting new metal areas 138 to the glass substrate 100. For the tape test, the new metal areas 138 were made into a 10-slice grid pattern in each direction. Pressure-sensitive tape 140 was then applied over the grid pattern. The tape 140 was then peeled off. The amount and type of removal were then compared with the description and illustration in the ASTM document. Less than 5% of the new metal areas 138 were removed from the glass article 128 by the tape 140. The test result was 4B according to ASTM standards. This indicates that the new metal areas 138, including copper, zinc, and silver, are highly adhered to the glass substrate 100.

[0125] Example 3. According to steps 202 and 204 of method 200, in the same manner as in Example 1, a first layer 120 of palladium as a catalytic metal is formed on the first surface 102 of the glass substrate 100 sample and then heat-treated.

[0126] Then, according to step 206 of method 200, the second layer 124 of the alloy is formed on the first layer 120 of the catalytic metal by electroless deposition. The composition of the electroless deposition is listed in Table 6 below.

[0127]

[0128] The temperature without an electric bath is maintained at 43°C. Therefore, the second layer 124 is an alloy of manganese as the first metal and copper as the second metal. According to step 208 of method 200, after a controlled temperature increase of 1°C per minute, the glass substrate 100 having the second layer 124 of the manganese-copper alloy is subjected to 400°C for 30 minutes in an air environment. Then, according to step 210 of method 200, the resulting glass article 128 is subjected to a temperature of 250°C for 30 minutes in a forming gas to reduce any oxidized copper produced in step 208 in the air environment.

[0129] Then, according to step 212 of method 200, a third layer 134 of the main metal (copper) is applied over the metal region 132 via an electroplating process. The third layer 134 has a thickness of 2.5 µm.

[0130] Then, according to step 214 of method 200, the glass article 128 having a third layer 134 of the main metal (copper) is subjected to a temperature of 350°C and a reduced pressure for 30 minutes.

[0131] Now refer to Figure 11 According to ASTM D3359-09, a cross-hatching tape test was performed on the resulting glass article 128 to test the adhesion of the resulting new metal regions 138 to the glass substrate 100. For the tape test, a 10-slice grid pattern was made to form the new metal regions 138 in each direction. Pressure-sensitive tape 140 was then applied over the grid pattern. The tape 140 was then peeled off. The amount and type of removal were then compared with the description and illustration in the ASTM document. The tape 140 removed less than 5% of the new metal regions 138 from the glass article 128. The test result was 4B according to ASTM standards. This shows that the new metal regions 138, including copper, manganese, and silver, adhered highly to the glass substrate 100, even though the manganese concentration in the no-bath was lower than that in Example 1.

[0132] Comparative Example 1. In Comparative Example 1, a first layer 120 of catalytic metal (silver) was added to the first surface 102 of the glass substrate 100, and a glass substrate 100 having the catalytic metal was produced at high temperature. No second layer 124 of the first metal (which readily forms oxide 130) and the second metal alloy was deposited on the first layer 120. Alternatively, a 2.5 µm thick copper layer was electroplated onto the first layer 120 of the catalytic metal and subjected to heating and depressurization for a certain period of time.

[0133] Now refer to Figure 12 A cross-hatching tape test was performed according to ASTM D3359-09 to test the adhesion of electroplated copper and silver to glass substrate 100. For the tape test, an eleven-slice grid pattern was made of metal in each direction. Pressure-sensitive tape 140 was then applied over the grid pattern. The tape 140 was then peeled off. The amount and type of removal were then compared with the description and illustration in the ASTM document. The removal of tape 140 from glass substrate 100 removed substantially all of the electroplated copper and spin-coated silver. According to ASTM standards, the test result was 0B. This shows that the electroplated copper and spin-coated silver have low adhesion to glass substrate 100. This illustrates that the step of applying an alloy including a first metal in method 200 is quite important for bonding the main metal to the first surface 102 of glass substrate 100, which forms an oxide 130 bonded to the first surface 102 of glass substrate 100.

[0134] Comparative Example 2. For Comparative Example 2, a first layer 120 of catalytic metal (silver) was added to the first surface 102 of the glass substrate 100 and subjected to high temperature. Then, instead of electroless deposition of a second layer 124, which is an alloy of the first metal (easily forming oxide 130) and the second metal, on the catalytic metal, only copper (not easily forming oxide 130) was electroless deposited on the first layer 120. Then, after a controlled temperature ramp-up rate of 1°C per minute in an air environment, the glass substrate 100 having the first silver layer 120 and the electroless deposited copper layer was subjected to 400°C for 30 minutes. The sample was then subjected to 250°C for 30 minutes in a gas environment. A 2.5 µm thick copper layer was electroplated over the electroless deposited copper layer. The sample was then subjected to 350°C for 30 minutes under reduced pressure.

[0135] Now refer to Figure 13 According to ASTM D3359-09, a cross-hatching strip test was performed on the obtained glass article to test the adhesion of electroplated copper, electroless deposited copper, and spin-coated silver to the glass substrate 100. For the strip test, a new metal area was created by cutting a 10-square pattern in each direction. Then, pressure-sensitive adhesive tape 140 was applied over the square pattern. The tape 140 was then peeled off. The amount and type of removal were then compared with the description and illustration in the ASTM document. The removal of tape 140 from the glass substrate 100 removed approximately 100% of the deposited metal. According to ASTM standards, the test result was 0B. This shows that the deposited metal adheres very little to the glass substrate 100. This illustrates that step 206 of method 200, which applies an alloy including a first metal, is quite important for the adhesion of the primary metal (e.g., copper) and other metals to the first surface 102 of the glass substrate 100, which forms an oxide 130 that bonds to the first surface 102 of the glass substrate 100.

[0136] Various modifications and variations that may be made without departing from the spirit and scope of the claims will be apparent to those skilled in the art.

Claims

1. A method for manufacturing glass articles, comprising: A first layer of catalytic metal is formed on the surface of a glass substrate, comprising: The surface is brought into contact with a suspension comprising nanoparticles of the catalytic metal dispersed in a liquid carrier; and Evaporation of liquid carrier; The glass substrate having the first layer of the catalytic metal is subjected to a temperature of 150°C to 600°C for at least 2 minutes; A second layer of an alloy of the first metal and the second metal is formed on the first layer; and A glass substrate having a second layer of the alloy of the first metal and the second metal on a first layer of the catalytic metal is subjected to a temperature of 250°C to 600°C for at least 30 minutes to form the glass article, the glass article comprising: (i) the glass substrate; (ii) an oxide of the first metal covalently bonded to the glass substrate; and (iii) a metal region bonded to the oxide of the first metal, the metal region comprising the catalytic metal in elemental form, the first metal in elemental form, and the second metal in elemental form.

2. The method of claim 1, further comprising: A third layer of the main metal is formed on the metal region of the glass article.

3. The method of claim 2, further comprising: The glass article having the third layer of the primary metal is subjected to a temperature of 250°C to 600°C for at least 30 minutes in an inert environment to form the glass article, the glass article comprising: (i) the glass substrate; (ii) an oxide of the first metal covalently bonded to the glass substrate; and (iii) a new metal region comprising the catalytic metal, the first metal in elemental form, the second metal in elemental form, and the primary metal in elemental form.

4. The method of claim 1, wherein The catalytic metal includes one or more of the following: silver, gold, cobalt, nickel, palladium, and platinum.

5. The method of claim 1, wherein The glass substrate includes a first surface and a second surface as the main surfaces of the glass substrate, and a sidewall surface defining a through hole, the through hole opening at the first surface and the second surface and extending through the glass substrate; and The oxide of the first metal is covalently bonded to the sidewall surface of the through hole.

6. The method of claim 3, wherein The glass substrate includes a first surface and a second surface as the main surface of the glass substrate, and a sidewall surface defining a through hole, the through hole opening at the first surface and the second surface and extending through the glass substrate. The oxide of the first metal is covalently bonded to the sidewall surface of the through hole; and The new metal region forms a conductive path through the through hole.

7. The method of claim 1, wherein The glass substrate includes a first surface and a second surface as the main surfaces of the glass substrate, and a sidewall surface defining a blind hole, the blind hole opening being located on one of the first surface or the second surface and extending partially through the glass substrate; and The oxide of the first metal is covalently bonded to the sidewall surface of the blind hole.

8. The method of claim 1, wherein The first metal of the second layer includes one or more of the following: tantalum, niobium, aluminum, manganese, rhenium, hafnium, chromium, zirconium, titanium, indium, tungsten, magnesium, molybdenum, nickel, and zinc; and The second metal of the second layer includes one or more of the following: silver, palladium, and copper.

9. The method of claim 1, wherein The second metal in the second layer is copper.

10. The method of claim 1, wherein The first metal in the second layer is manganese or zinc.

11. The method of claim 1, wherein Forming the second layer of the alloy includes electrolessly plating the second layer onto the first layer using a solution comprising a salt of the first metal dissolved in the solution and a salt of the second metal dissolved in the solution.

12. The method of claim 11, wherein The solution further comprises formaldehyde and has a pH greater than 11.

13. The method of claim 11, wherein The solution further comprises dimethylamine borane and has a pH of 6 to 8.

14. The method of claim 1, wherein The glass substrate having a second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal is subjected to a temperature of 250°C to 600°C in the presence of air; and The method further includes: After the glass article is subjected to a temperature of 375°C to 425°C, it is subjected to a temperature of 225°C to 275°C for at least 30 minutes in the presence of a forming gas.

15. The method of claim 2, wherein The primary metals include one or more of the following: silver, gold, cadmium, chromium, copper, nickel, lead, platinum, and tin.

16. The method of claim 1, wherein Exposing the glass substrate having the first layer of the catalytic metal to a temperature of 150°C to 600°C for at least 2 minutes includes: The glass substrate having the first layer of the catalytic metal is subjected to a temperature of 325°C to 375°C for at least 2 minutes; and Exposing a glass substrate having a second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal to a temperature of 250°C to 600°C for at least 30 minutes includes: exposing the glass substrate having a second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal to a temperature of 300°C to 425°C for at least 30 minutes.

17. The method of claim 3, wherein Exposing the glass substrate having the first layer of the catalytic metal to a temperature of 150°C to 600°C for at least 2 minutes includes: The glass substrate having the first layer of the catalytic metal is subjected to a temperature of 325°C to 375°C for at least 2 minutes; Exposing a glass substrate having a second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal to a temperature of 250°C to 600°C for at least 30 minutes includes: exposing the glass substrate having a second layer of the alloy of the first metal and the second metal on the first layer of the catalytic metal to a temperature of 300°C to 425°C for at least 30 minutes; and Exposing the glass article having the third layer of the main metal to a temperature of 250°C to 600°C for at least 30 minutes in an inert environment includes: exposing the glass article having the third layer of the main metal to a temperature of 300°C to 400°C for at least 30 minutes in an inert environment.

18. A glass insert, comprising: A glass substrate, the glass substrate comprising: a first surface and a second surface serving as the main surfaces of the glass substrate; and a through hole extending from the first surface through the thickness of the glass substrate to the second surface, the through hole having sidewall surfaces and a central axis; Metal region, the metal region being disposed within the through hole around the central axis; and An oxide of a first metal, the oxide of the first metal being covalently bonded to the sidewall surface of the through hole, the oxide of the first metal being disposed between the sidewall surface and the metal region, the metal region comprising the first metal in elemental form and the second metal in elemental form.

19. The glass insert of claim 18, wherein... The first metal is one or more of the following: tantalum, niobium, aluminum, manganese, rhenium, hafnium, chromium, zirconium, titanium, indium, tungsten, magnesium, molybdenum, nickel, and zinc; and The second metal is one or more of the following: silver, palladium, and copper.

20. The glass insert of claim 18, wherein... The oxide of the first metal has an enthalpy of formation, the absolute value of which is greater than 325 kJ per mole; and The oxide of the second metal has a formation enthalpy, the absolute value of which is less than 175 kJ per mole.

21. The glass insert of claim 18, wherein... The first metal is manganese, and the second metal is copper.

22. The glass insert of claim 18, wherein... The metallic region further includes silver.

Images