Method for manufacturing glass substrate for semiconductor and glass substrate for semiconductor

Abstract

Disclosed are a method for manufacturing a glass substrate for a semiconductor and a glass substrate for a semiconductor. The disclosed method for manufacturing a multilayer glass substrate for a semiconductor comprises: a preparation step of preparing a glass core; an etching step of forming a trench in the glass core in a thickness direction; a bonding metal layer forming step of forming a bonding metal layer on a surface defining the trench; and an electrode forming step of forming an electrode by filling the trench, in which the bonding metal layer is formed, with a conductive paste containing conductive particles, wherein the electrode forming step includes: a paste filling step of filling the inside of the bonding metal layer with the conductive paste; and a firing step of forming a solidified electrode by applying heat to the bonding metal layer and the conductive paste, and bonding the electrode to the bonding metal layer.

Description

Manufacturing method of glass substrate for semiconductor and glass substrate for semiconductor

[0001] The present invention relates to a method for manufacturing a glass substrate, and more particularly, to a method for manufacturing a glass substrate for semiconductors and a glass substrate for semiconductors.

[0002] In the manufacturing of electronic components, implementing circuits on semiconductor wafers is called the Front-End (FE) process. Assembling the wafers into a usable state for actual products is called the Back-End (BE) process. This Back-End (BE) process includes the packaging (Multi-Chip Package) process, which assembles multiple semiconductors produced in wafer form into a bundle suitable for device integration.

[0003] Semiconductor technology is advancing in diverse forms, including sub-micron nanometer line widths, cell counts exceeding 10 million, high-speed operation, and high heat dissipation. However, the technology to perfectly package these devices remains relatively lacking. Consequently, the electrical performance of semiconductors is often determined more by packaging technology and the resulting electrical connections than by the semiconductor technology itself.

[0004] Ceramic or resin is typically used as the packaging substrate material. However, ceramic substrates have high resistance and dielectric constants, making it difficult to mount high-performance, high-frequency semiconductor devices on them. Resin substrates, while relatively easy to mount high-performance, high-frequency semiconductor devices on, have limitations in reducing wiring pitch, and their uneven surface makes them particularly unsuitable for use in high-performance semiconductor packaging, which is undergoing continuous miniaturization.

[0005] A method using smooth-surfaced silicon as an alternative packaging substrate has been developed, but this method has the disadvantages of being expensive and difficult to manufacture on a large scale. In particular, silicon packaging substrates have a high coefficient of thermal expansion (CTE), making them unsuitable for use in die packaging applications with high-density micro-sized bumps, such as those used in high-bandwidth memory (HBM).

[0006] Glass substrates are recently gaining attention as a potential replacement for silicon substrates. Glass substrates are more cost-effective than silicon substrates and can be designed and manufactured on larger surfaces, enabling the production of a greater number of chips. Furthermore, the extremely smooth and flat surface of glass allows for precise circuit design, making them advantageous for implementing high-performance, high-density circuits.

[0007] However, when forming electrodes (or electrical wiring) on ​​a glass substrate using a conductive metal that functions as an electrical connection medium, problems with adhesion reliability and yield are continuously being raised, such as the adhesive strength of the conductive metal being low due to the surface characteristics of the glass substrate, causing easy peel-off from the glass substrate.

[0008] The matters described in the background art above are intended to help understand the background of the invention and may include matters that are not publicly disclosed prior art.

[0009] The technical problem to be solved by the present invention is to provide a method for manufacturing a semiconductor glass substrate and a semiconductor glass substrate capable of improving the adhesion of conductive particles to the glass substrate and thereby improving the electrode peel-off problem.

[0010] According to one aspect of the present invention as a means for solving the problem, a method for manufacturing a glass substrate for semiconductors is provided, including a preparation step of preparing a glass core, an etching step of forming a trench in the thickness direction in the glass core, a bonding metal layer forming step of forming a bonding metal layer on a surface defining the trench, and an electrode forming step of filling a trench in which the bonding metal layer is formed with a conductive paste containing conductive particles to form an electrode.

[0011] In a method for manufacturing a glass substrate for semiconductors according to one aspect of the present invention, the electrode forming step may include a paste filling step of filling the conductive paste inside the bonding metal layer, and a firing step of applying heat to the bonding metal layer and the conductive paste to form a solidified electrode and bonding the bonding metal layer and the electrode.

[0012] In the paste filling step of the method for manufacturing a semiconductor glass substrate according to one aspect of the present invention, a screen mask having an open pattern corresponding to the trench is placed on the upper surface of the glass core, and a conductive paste is applied on the screen mask, and then a squeegee moving from one side to the other is used to pass the conductive paste through the open pattern portion of the screen mask, thereby filling the trench with the conductive paste.

[0013] In the firing step of the method for manufacturing a semiconductor glass substrate according to one aspect of the present invention, an electrode may be formed by firing at a temperature lower than the softening point of the glass core, and the electrode and the bonding metal layer may be reacted to form a mutual eutectic bond.

[0014] In a method for manufacturing a glass substrate for semiconductors according to one aspect of the present invention, the conductive particles may be silver (Ag), and the bonding metal layer may include one of molybdenum (Mo), titanium (Ti), a titanium-tungsten alloy (TiW alloy), chromium (Cr), and a nickel-chromium alloy (NiCr alloy).

[0015] In a method for manufacturing a semiconductor glass substrate according to one aspect of the present invention, the conductive paste includes 70 to 90 wt% of silver (Ag) powder, 5 to 10 wt% of a binder, 4 to 15 wt% of an organic solvent, and 1 to 5 wt% of an additive, wherein the organic solvent may be any one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, and isopropyl alcohol, or a combination thereof, the binder may be an acrylic binder or a nitrocellulose binder, and the additive may be any one selected from the group consisting of glycerin, polyethylene glycol (PEG), and glass powder, or a combination thereof.

[0016] In the preparation step of the method for manufacturing a semiconductor glass substrate according to one aspect of the present invention, the glass core may be an oxide-reinforced glass having a thickness of 20 to 30 μm and having high strength, corrosion resistance, transparency, and hardness at room temperature.

[0017] In a method for manufacturing a semiconductor glass substrate according to one aspect of the present invention, the glass core may be borosilicate glass or aluminosilicate glass.

[0018] In a method for manufacturing a glass substrate for semiconductors according to one aspect of the present invention, the bonding metal layer forming step may include a cover layer forming step of forming a cover layer on the glass core with a pattern hole formed in a shape corresponding to the trench, a deposition step of forming a bonding metal layer in the trench exposed through the pattern hole by spraying metal particles at high pressure toward the cover layer, and a cover layer removing step of removing the cover layer.

[0019] Here, the cover layer forming step may be comprised of a first step of forming a photosensitive layer on the glass core, a second step of placing a mask covering the remaining portion except for the trench on the photosensitive layer and then exposing it, and a third step of developing the exposed portion to form a cover layer having a pattern hole.

[0020] According to another aspect of the present invention as a means for solving the problem, a semiconductor glass substrate is provided, which includes a glass core, a trench formed in the thickness direction of the glass core, a bonding metal layer formed on a surface dividing the trench, and an electrode bonded to the bonding metal layer within the trench except for a surface aligned on the same plane as the surface of the glass core.

[0021] In a semiconductor glass substrate according to another aspect of the present invention, the electrode may be formed by filling a conductive paste containing conductive particles into a trench in which a bonding metal layer is formed and then firing the trench.

[0022] In a semiconductor glass substrate according to another aspect of the present invention, the conductive particles may be silver (Ag), and the bonding metal layer may include one of molybdenum (Mo), titanium (Ti), titanium-tungsten alloy (TiW alloy), chromium (Cr), and nickel-chromium alloy (NiCr alloy).

[0023] In another aspect of the present invention, in a semiconductor glass substrate, the conductive paste comprises 70 to 90 wt% of silver (Ag) powder, 5 to 10 wt% of a binder, 4 to 15 wt% of an organic solvent, and 1 to 5 wt% of an additive, wherein the organic solvent may be any one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, and isopropyl alcohol, or a combination thereof, the binder may be an acrylic binder or a nitrocellulose binder, and the additive may be any one selected from the group consisting of glycerin, polyethylene glycol (PEG), and glass powder, or a combination thereof.

[0024] In a semiconductor glass substrate according to another aspect of the present invention, the electrode can react with the bonding metal layer to form a eutectic bond.

[0025] In a semiconductor glass substrate according to another aspect of the present invention, the glass core may be an oxide-reinforced glass having a thickness of 20 to 30 μm and having high strength, corrosion resistance, transparency, and hardness at room temperature.

[0026] In a semiconductor glass substrate according to another aspect of the present invention, the glass core may be borosilicate glass or aluminosilicate glass.

[0027] According to the present invention, by depositing a bonding metal layer in a trench (a groove or hole in which an electrode or electrical wiring will be formed) and filling it with a conductive paste and then firing, a high-density electrode in which conductive particles are strongly fused to each other can be formed, and during the firing process, the metal particles of the bonding metal layer and the conductive particles react with each other to form a strong bond, so that the adhesive strength of the electrode can be greatly increased.

[0028] Furthermore, since the electrode is formed in a structure in which at least three sides are in contact with the glass substrate, the adhesive strength of the electrode is further enhanced, which has the effect of significantly improving the electrode peel-off that occurs in conventional glass substrates, and thus, a highly reliable semiconductor glass substrate with uniform and strong electrode bonding can be provided. Furthermore, when silver is used as the electrode material, firing in an air atmosphere is possible, which can reduce process costs.

[0029] FIG. 1 is a flowchart illustrating a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0030] FIG. 2 is a process schematic diagram schematically illustrating a manufacturing process of a semiconductor glass substrate according to an embodiment of the present invention.

[0031] FIG. 3 is a process schematic diagram schematically illustrating a process of forming a bonding metal layer in a trench in a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0032] FIG. 4 is a drawing schematically illustrating a conductive paste filling step in a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0033] FIG. 5 is a cross-sectional configuration diagram of a semiconductor glass substrate manufactured by a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0034] FIG. 6 is an enlarged view of the main part of the semiconductor glass substrate illustrated in FIG. 5, and is an enlarged view of the main part of the present invention, showing part 'A' of FIG. 5 in an enlarged manner.

[0035] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0036] In describing embodiments of the present invention, identical or similar components will be assigned the same reference numbers, and redundant descriptions thereof will be omitted. Furthermore, if a detailed description of a related known technology is deemed to obscure the gist of the embodiments disclosed herein, such detailed description will be omitted.

[0037] In addition, the attached drawings are only intended to facilitate easy understanding of the embodiments disclosed in this specification, and the technical ideas disclosed in this specification are not limited by the attached drawings, and it is to be understood that all modifications, equivalents, or substitutes included in the spirit and technical scope of the present invention are included.

[0038] Additionally, when a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may also be other components in between.

[0039] On the other hand, when it is said that a component is "directly connected" or "directly connected" to another component, it should be understood that there are no other components in between.

[0040] In addition, it should be understood that terms such as “include,” “have,” and “have” used in describing embodiments of the present invention are intended to specify the presence of a feature, number, step, operation, component, part, or combination thereof of the invention, and do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0041] The drawings are intended solely to facilitate understanding of the invention and should not be construed as limiting the scope of the invention. Furthermore, it should be noted that relative thicknesses, lengths, and sizes in the drawings may be exaggerated for convenience and clarity of explanation.

[0042] FIG. 1 is a flowchart for explaining a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention, and FIG. 2 is a process schematic diagram schematically illustrating a process for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0043] FIG. 1 is a flowchart for explaining a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention, and FIG. 2 is a process schematic diagram schematically illustrating a process for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0044] Referring to FIGS. 1 and 2, a method for manufacturing a semiconductor glass substrate according to an embodiment includes a preparation step (S100) of preparing a glass core (10), an etching step (S200) of forming a trench (20) in the thickness direction in the glass core (10), a bonding metal layer forming step (S300) of forming a bonding metal layer (25) on a surface defining the trench (20), and an electrode forming step (S400) of filling a trench (20) in which the bonding metal layer (25) is formed with a conductive paste (32) and firing the trench to form an electrode.

[0045] In the method for manufacturing a semiconductor glass substrate according to an embodiment, the glass core (Glass core), which is the main material, i.e., the glass core (10) prepared in the preparation step (S100), may be an oxide-tempered glass. In the method for manufacturing a semiconductor glass substrate according to an embodiment, the glass core (10), which is the main material, may be a tempered glass whose main component is an oxide, which has a thickness of 20 to 30 ㎛, high strength and corrosion resistance at room temperature, and transparency and hardness.

[0046] As a preferred example, the glass core (10) that is the main material in the method for manufacturing a semiconductor glass substrate according to the embodiment may be borosilicate glass that is a glass that mainly contains boric acid instead of silicic acid, contains at least 5% of boric acid, has chemical acid resistance and weather resistance due to a low coefficient of expansion, and has excellent thermal shock resistance.

[0047] As another preferred example, the glass core (10) that is a main material in the method for manufacturing a semiconductor glass substrate according to the embodiment may be an aluminosilicate glass that is made of alumina and boron oxide and has similar properties to borosilicate glass, but has superior heat resistance and high chemical resistance compared to borosilicate glass.

[0048] In the etching step (S200), a process of forming a trench (20) in the thickness direction in the glass core (10) through etching can be performed. In the etching step (S200), a predetermined pattern is formed on the glass core (10) using a photosensitive agent through a known photolithography process for drawing a semiconductor circuit on a wafer, and an etching process is performed using the photosensitive agent with the pattern formed thereon as a mask, thereby forming the trench (20).

[0049] For reference, the term 'trench (20)' used in describing the present invention means a fine hole (Via) or groove formed in the thickness direction in the glass core (10) through an etching process.

[0050] In the etching step (S200), a trench (20) can be formed in the glass core (10) through dry etching using plasma or laser or wet etching using an etchant. In the case of wet etching, HF or NaOH can be used as the etchant. HF has the advantage of being able to etch at room temperature and having a fast etching speed, and NaOH has the advantage of being able to etch precisely, although its etching conditions are more demanding than those of HF.

[0051] Depending on the embodiment, a LIDE (Laser induced Deep Etching) method may be applied, which performs pre-processing with a laser and then completes the trench (20) through post-processing using chemical etching. For reference, the LIDE method is a technology that induces a selective chemical phase change in glass using a laser and then selectively etches only the area deformed by the laser through a chemical etching process to form a trench.

[0052] Among the trenches (20, microscopic holes and grooves) formed in the glass core (10) in the etching step (S200), the groove (20a) can be formed with a specific depth and width. Considering that the thickness of the glass core (10) is 20 to 30 ㎛, the depth (d) of the groove (20a) among the trenches (20) (microscopic holes and grooves) formed in the glass core (10) in the etching step (S200) is preferably 0.8 to 1.2 ㎛, and its width (groove width, w) is preferably 1.8 to 2.2 ㎛.

[0053] The bonding metal layer forming step (S300) is a step of forming a bonding metal layer (25) with a constant thickness on the wall surface or the wall surface and the bottom surface of the trench (20) formed in the glass core (10). In the bonding metal layer forming step (S300), the bonding metal layer (25) can be formed by depositing metal particles capable of forming a strong bond with glass with a constant thickness on the wall surface or the wall surface and the bottom surface that divides the trench (20).

[0054] In the bonding metal layer forming step (S300), the bonding metal layer (25) may be composed of a metal that can be well attached to glass and has good matching properties with the particles (conductive particles) of the electrode formed in the electrode forming step (S400) described below. For example, if the conductive particles constituting the electrode are silver (Ag), the bonding metal layer (25) may be composed of one of molybdenum (Mo), titanium (Ti), titanium-tungsten alloy (TiW alloy), chromium (Cr), and nickel-chromium alloy (NiCr alloy).

[0055] In the bonding metal layer forming step (S300), the bonding metal layer (25) can be formed with a constant thickness (t1) on the surface defining the trench (20) through sputtering, which sprays and deposits the mentioned metal particles (Mo, Ti, TiW alloy, Cr, NiCr alloy, etc.) under strong pressure in a vacuum atmosphere. As a preferred example, the bonding metal layer (25) formed in the trench (20) can be formed with a single layer structure having a thickness of 50 nm.

[0056] The process of forming a bonding metal layer in a trench in the bonding metal layer formation step will be examined in more detail with reference to Fig. 3.

[0057] FIG. 3 is a process schematic diagram schematically illustrating a process of forming a bonding metal layer in a trench in a method for manufacturing a semiconductor glass substrate according to an embodiment of the present invention.

[0058] Referring to Fig. 3, the bonding metal layer forming step (S300) includes a cover layer forming step (S302), a deposition step (S304), and a cover layer removing step (S306). In the cover layer forming step (S302), a cover layer (70) having a pattern hole (72) formed in a shape corresponding to a trench (20) on a glass core (10) is formed, and in the deposition step (S304), a process may be performed to form a bonding metal layer (25) in the trench (20) exposed through the pattern hole (72) by spraying metal particles at high pressure toward the cover layer (70).

[0059] The cover layer forming step (S302) includes a first step (S302-1) of forming a photosensitive layer (50) by applying a photosensitive agent to a certain thickness on a glass core (10). The cover layer forming step (S302) also includes a second step (S302-2) of placing a mask (60) covering the remaining portion except for the trench (20) on the photosensitive layer (50) formed in the first step (S302-1) and then exposing it, and a third step (S302-3) of forming a cover layer (70) having a pattern hole (72) by developing the exposed portion.

[0060] In the cover layer removal step (S306), a process may be performed to remove the cover layer (70) and unnecessary deposits on the cover layer (70) at once, for example, through dry ashing using plasma. In some cases, the cover layer (70) and unnecessary deposits may be removed through a CMP (Chemical Mechanical Polishing) process that flattens the surface of the glass core (10) while removing the cover layer (70) and unnecessary deposits.

[0061] The electrode forming step (S400) is a step of forming an electrode (30) by filling a trench (20) in which a bonding metal layer (25) is formed to a constant thickness with a conductive paste (32) containing conductive particles. The electrode forming step (S400) includes a paste filling step (S402) of filling the inside of the bonding metal layer (25) with a conductive paste (32), and a firing step (S404) of applying heat to the bonding metal layer (25) and the conductive paste (32) to form a solidified electrode and bonding the bonding metal layer (25) and the electrode.

[0062] In the paste filling step (S402), as shown in FIG. 4, a screen mask (M) having an open pattern (P) corresponding to a trench (20) is placed on the upper surface of the glass core (10), and a conductive paste (32) is applied on the screen mask (M), and then a squeegee (S) that moves from one side to the other (see the direction of the arrow) is used to pass the conductive paste (32) through the open pattern (P) portion, a type of screen printing method may be used.

[0063] In an embodiment, the conductive particles, which are the main material constituting the conductive paste (32), may be silver (Ag). Silver (Ag) has an electrical conductivity of about 63.01X10 6 It is the highest among all metals in S / m (Siemens / meter). In particular, when silver (Ag) is used as the main base material of conductive paste (32), sintering is possible in an air atmosphere, which can reduce the process and process costs. This is due to the characteristic of silver that it is less sensitive to oxidation than other metals.

[0064] In an embodiment, the conductive paste (32) may include silver powder, a binder that helps to bind the silver powder to each other and adhere to a substrate, an organic solvent for uniform dispersion of the silver powder, and an additive for controlling sintering temperature, paste viscosity, and oxidation prevention. In an embodiment, a preferred composition of the conductive paste (32) may be 70 to 90 wt% of silver powder, 5 to 10 wt% of binder, 4 to 15 wt% of organic solvent, and 1 to 5 wt% of additive.

[0065] In an embodiment, the organic solvent may be one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, and isopropyl alcohol, or a combination thereof. The binder may be an acrylic binder or a nitrocellulose binder. And the additive may be one selected from the group consisting of glycerin, polyethylene glycol (PEG), and glass powder, or a combination thereof.

[0066] The firing step (S404) is a process of forming a solidified electrode by applying heat to the conductive paste (32) filled in the trench (20) to remove organic solvents, binders, additives, etc. In the firing step (S404), a solidified electrode can be formed by performing firing under specific temperature conditions. In the firing step (S404), a solidified electrode (30) can be formed by performing firing at a temperature lower than the softening point of the glass core (10).

[0067] In the process of forming a solidified electrode (30) by sintering, the conductive particles constituting the electrode (30) and the bonding metal layer (25) can react with each other to the applied heat and form a eutectic bond. As a result, the electrode (30) and the bonding metal layer (25) can be firmly bonded to each other while forming a eutectic bonding layer (27, see FIG. 6).

[0068] That is, in the firing step (S404) according to the embodiment, the processing of forming an electrode (30) by solidifying the conductive paste (32) through a single firing treatment and the processing of bonding the electrode (30) and the bonding metal layer (25) can be performed simultaneously.

[0069] When using borosilicate tempered glass with a softening point of approximately 820°C as the glass core (10), the firing temperature is preferably approximately 450°C or higher and 600°C or lower.

[0070] As mentioned, silver (Ag) is less susceptible to oxidation than other conductive metals, allowing for sintering in air. However, at temperatures exceeding 700°C, the surface of silver (Ag) can oxidize. Therefore, it is recommended to use the lowest possible temperature during sintering to prevent oxidation. However, below 450°C, the adhesion between silver particles deteriorates, and organic solvents or binders may remain. Therefore, the sintering temperature is preferably between 450°C and 600°C.

[0071] The firing step (S404) may include a drying process (not shown). By performing an additional drying process after the firing process, the organic solvent remaining within the conductive paste (32) can be more reliably removed. It is preferable to perform the drying process at a temperature and time that allows the organic solvent to be vaporized and removed while also allowing the temperature of the electrode to be gradually cooled.

[0072] According to the manufacturing method according to the embodiment of the present invention, by depositing a bonding metal layer in a trench (a groove or hole in which an electrode or electrical wiring will be formed) and filling it with a conductive paste and then firing, a high-density electrode in which conductive particles are strongly fused to each other can be formed, and during the firing process, the metal particles of the bonding metal layer and the conductive particles react with each other to form a strong bond, so that the adhesive strength of the electrode can be greatly increased.

[0073] Furthermore, since the electrode is formed in a structure in which at least three sides are in contact with the glass substrate, the adhesive strength of the electrode is further enhanced, which has the effect of significantly improving the electrode peel-off that occurs in conventional glass substrates, and thus, a highly reliable semiconductor glass substrate with uniform and strong electrode bonding can be provided. Furthermore, when silver is used as the electrode material, firing in an air atmosphere is possible, which can reduce process costs.

[0074] FIG. 5 is a cross-sectional view of a semiconductor glass substrate manufactured by the aforementioned method for manufacturing a semiconductor glass substrate, and FIG. 6 is an enlarged view of the main part of the present invention, which enlarges the 'A' portion of FIG. 5.

[0075] Referring to FIGS. 5 and 6, a semiconductor glass substrate (1) includes a glass core (10). A trench (20) is formed in the glass core (10), and a bonding metal layer (25) and an electrode (30) may be formed in the trench (20). The trench (20) may be a groove (20a) or a microscopic hole formed in the thickness direction of the glass core (10), and the electrode (30) may be formed in the trench (20) so as to have a surface aligned on the same plane as the surface of the glass core (10).

[0076] The glass core (10) may be a tempered glass having a thickness of 20 to 30 ㎛ and a first surface (12, upper surface in the drawing) that is even and a second surface (14, lower surface in the drawing) that is parallel to the first surface, and the trench (20) may be formed by forming a predetermined pattern on the glass core (10) with a photosensitive agent through a photolithography process and performing an etching process using the photosensitive agent with the pattern formed thereon as a mask.

[0077] For reference, the drawing (Fig. 5) illustrates an example of a configuration in which a groove-shaped trench (20a) is formed on the first side (12) of the glass core (10), but is not limited thereto. Depending on the embodiment, a groove-shaped trench (20a) may be formed on the second side (14) of the glass core (10), or a groove-shaped trench (20a) may be formed on both the first side (12) and the second side (14).

[0078] The glass core (10) may be tempered glass having a thickness of 20 to 30 μm. In an embodiment, the glass core (10) may be tempered glass whose main component is oxide, having high strength, corrosion resistance, transparency, and hardness at room temperature. As a preferred example, the glass core (10) may be borosilicate tempered glass. Depending on the embodiment, it may also be aluminosilicate tempered glass.

[0079] Borosilicate tempered glass is a glass that uses boric acid as its main ingredient instead of silica, and contains at least 5% boric acid. It has a low coefficient of expansion, chemical resistance to acid and weather resistance, and excellent thermal shock resistance, making it suitable for semiconductor glass substrates. Aluminum silicate tempered glass is made of alumina and boron oxide, and has similar properties to borosilicate glass, but has superior heat resistance and high chemical resistance compared to borosilicate glass, making it suitable for semiconductor glass substrates.

[0080] Among the trenches (fine holes and grooves) formed in the glass core (10), the groove (20a) can be formed with a specific depth and width. Considering that the thickness of the glass core (10) is 20 to 30 ㎛, among the trenches (fine holes and grooves) formed in the glass core (10), the groove (20a) can be formed with a depth (d) of approximately 0.8 to 1.2 ㎛ and a width (width of the groove, w) of approximately 1.8 to 2.2 ㎛.

[0081] The bonding metal layer (25) mediates a strong bond between the electrode (30) and the glass core (10). The bonding metal layer (25) can be formed with a constant thickness on all surfaces that define the trench (20). For example, when the trench (20) is formed in a groove shape with a rectangular cross-section (see shape 20a in FIG. 5), the bonding metal layer (25) can be formed with a constant thickness on all surfaces that define the trench (20), i.e., the vertical walls facing each other and the flat bottom surface that interconnects the bottoms of these walls.

[0082] The bonding metal layer (25) can be formed by depositing metal particles capable of forming a strong bond with glass to a certain thickness on the surface that defines the trench (20). The bonding metal layer (25) can be composed of a metal that can adhere well to glass and has good matching properties with the particles (conductive particles) of the electrode. For example, when the electrode is composed of silver (Ag), the bonding metal layer (25) can be composed of one of the metals Mo, Ti, TiW alloy, Cr, and NiCr alloy.

[0083] The bonding metal layer (25) can be formed with a constant thickness (t1) on the surface defining the trench (20) through a sputtering process in which the aforementioned metal particles (Mo, Ti, TiW alloy, Cr, NiCr alloy, etc.) are sprayed and deposited on the surface of the glass core (10) under strong pressure in a vacuum atmosphere. As a preferred example, the bonding metal layer (25) formed in the trench (20) can be formed with a single layer structure having a thickness of 50 nm.

[0084] The bonding metal layer (25) can be formed, for example, by forming a cover layer (see the preceding FIG. 3) on the glass core (10) in which a pattern hole is formed in a shape corresponding to the trench (20), spraying metal particles at high pressure toward the cover layer to deposit and form the bonding metal layer (25) on the surface of the trench (20) exposed through the pattern hole (the surface that divides the trench), and then removing the cover layer on the glass core together with unnecessary deposits through dry ashing or the like.

[0085] The electrode (30) can be formed from a conductive paste (32) filled in a trench (20). The electrode (30) can be formed by filling the trench (20) with the conductive paste (32) and firing at a temperature lower than the softening point of the glass core (10). For example, when borosilicate tempered glass having a softening point of approximately 820°C is used as the glass core (10), the firing temperature can be in a range of 450°C or more and 600°C or less.

[0086] The electrode (30) can be bonded to the bonding metal layer (25) within the trench (20) while forming a firm bond, except for the surface aligned on the same plane as the surface of the glass core (the surface exposed to the outside). This is because, in the process of forming the electrode (30) solidified from the conductive paste (32) by firing, the conductive particles constituting the electrode (30) and the metal particles of the bonding metal layer (25) react with each other in response to the applied heat, so that the interface region of the conductive paste (32) and the bonding metal layer (25) is eutectically bonded to form a eutectic bonding layer (27).

[0087] The conductive paste (32) constituting the electrode (30) includes conductive particles. In an embodiment, the conductive particles may be silver (Ag). Silver (Ag) has an electrical conductivity of about 63.01X10 6It is the highest among all metals in S / m (Siemens / meter), and especially when silver (Ag) is used as the main base material of conductive paste (32), it is possible to perform sintering treatment in an air atmosphere, which can reduce the process and process cost. This is due to the characteristic of silver that it is less sensitive to oxidation than other metals.

[0088] In an embodiment, the conductive paste (32) may include silver powder as a main material, a binder that helps to bind the silver powder to each other and adhere to the substrate, an organic solvent for uniform dispersion of the silver powder, and an additive for controlling the sintering temperature, paste viscosity, and oxidation prevention. In an embodiment, a preferred composition of the conductive paste (32) may be 70 to 90 wt% of silver powder, 5 to 10 wt% of binder, 4 to 15 wt% of organic solvent, and 1 to 5 wt% of additive.

[0089] In an embodiment, the organic solvent may be one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, and isopropyl alcohol, or a combination thereof. The binder may be an acrylic binder or a nitrocellulose binder, and the additive may be one selected from the group consisting of glycerin, polyethylene glycol (PEG), and glass powder, or a combination thereof.

[0090] As mentioned, silver (Ag) is less susceptible to oxidation than other conductive metals. Therefore, sintering is possible in air. However, because the surface of silver (Ag) can oxidize at high temperatures, it is recommended to use the lowest possible temperature during sintering to prevent oxidation. However, if the heating temperature is insufficient, the fusion between silver particles will deteriorate and organic solvents or binders may remain. Therefore, the sintering temperature is preferably around 450°C to 600°C.

[0091] Semiconductor glass substrates with this configuration have electrodes formed in a trench electrode configuration where at least three sides are bonded to the glass substrate. This significantly enhances the adhesion of the electrodes to the glass substrate, thereby significantly improving problems of prior art, such as electrode peel-off. Consequently, a highly reliable product with robust and uniform electrode adhesion quality can be provided.

[0092] The above description is merely an example of the technical idea of ​​the present invention, and those skilled in the art will appreciate that various modifications and variations can be made without departing from the essential characteristics of the present invention.

[0093] Accordingly, the embodiments disclosed in the present invention are intended to illustrate, rather than limit, the technical concept of the present invention, and the scope of the technical concept of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical concepts within the scope equivalent thereto should be construed as being included within the scope of the present invention.

Claims

Preparatory steps for preparing the glass core; An etching step for forming a trench in the thickness direction in the above glass core; A bonding metal layer forming step of forming a bonding metal layer on a surface that divides the trench; and A method for manufacturing a glass substrate for semiconductors, comprising: an electrode forming step of forming an electrode by filling a trench in which the bonding metal layer is formed with a conductive paste containing conductive particles. In the first paragraph, The above electrode forming step is, A paste filling step of filling the conductive paste inside the above bonding metal layer; and A method for manufacturing a glass substrate for semiconductors, comprising a step of applying heat to the bonding metal layer and conductive paste to form a solidified electrode and a sintering step of bonding the bonding metal layer and the electrode. In the second paragraph, In the above paste filling step, A method for manufacturing a glass substrate for semiconductors, wherein a screen mask having an open pattern corresponding to the trench is placed on the upper surface of a glass core, a conductive paste is applied on the screen mask, and then a squeegee moving from one side to the other is used to pass the conductive paste through the open pattern portion of the screen mask to fill the trench with the conductive paste. In the second paragraph, In the above firing step, A method for manufacturing a glass substrate for semiconductors, comprising forming an electrode by firing at a temperature lower than the softening point of the glass core and reacting the electrode with a bonding metal layer to form a eutectic bond. In the first paragraph, The above conductive particles are silver (Ag), A method for manufacturing an organic film for a semiconductor, wherein the bonding metal layer comprises one of molybdenum (Mo), titanium (Ti), titanium-tungsten alloy (TiW alloy), chromium (Cr), and nickel-chromium alloy (NiCr alloy). In the first paragraph, The above conductive paste, 70 to 90 wt% silver (Ag) powder, 5 to 10 wt% binder, 4 to 15 wt% of organic solvent, Contains 1 to 5 wt% of additives, The above organic solvent is one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, isopropyl alcohol, or a combination thereof, The above binder is an acrylic binder or a nitrocellulose binder, A method for manufacturing a glass substrate for semiconductors, wherein the additive is one selected from the group consisting of glycerin, polyethylene glycol (PEG), glass powder, or a combination thereof. In the first paragraph, A method for manufacturing a semiconductor glass substrate, wherein the glass core in the above preparation step is an oxide-reinforced glass having a thickness of 20 to 30 ㎛ and high strength, corrosion resistance, transparency, and hardness at room temperature. In paragraph 7, A method for manufacturing a glass substrate for semiconductors, wherein the above glass core is borosilicate glass or aluminosilicate glass. In the first paragraph, The above bonding metal layer forming step is, A cover layer forming step of forming a cover layer having a pattern hole formed in a shape corresponding to the trench on the glass core; A deposition step of forming a bonding metal layer in a trench exposed through the pattern hole by spraying metal particles at high pressure toward the cover layer; and A method for manufacturing a glass substrate for semiconductors, comprising a cover layer removing step of removing the cover layer. In paragraph 9, The above cover layer forming step is: A first step of forming a photosensitive layer on the glass core; A second step of placing a mask covering the remaining portion except for the trench on the photosensitive layer and then exposing it; and A method for manufacturing a semiconductor glass substrate, comprising a third step of developing an exposed portion to form a cover layer having a pattern hole. Glass core; A trench formed in the thickness direction of the above glass core; A bonding metal layer formed on a surface that divides the trench; and A semiconductor glass substrate, comprising an electrode bonded to the bonding metal layer within the trench, except for a surface aligned on the same plane as the surface of the glass core. In paragraph 11, A semiconductor glass substrate, wherein the electrode is formed by filling a conductive paste containing conductive particles into a trench in which a bonding metal layer is formed and then firing the same. In paragraph 12, The above conductive particles are silver (Ag), An organic film for semiconductors, wherein the bonding metal layer comprises one of molybdenum (Mo), titanium (Ti), titanium-tungsten alloy (TiW alloy), chromium (Cr), and nickel-chromium alloy (NiCr alloy). In paragraph 12, The above conductive paste, 70 to 90 wt% silver (Ag) powder, 5 to 10 wt% binder, 4 to 15 wt% of organic solvent, Contains 1 to 5 wt% of additives, The above organic solvent is one selected from the group consisting of butyl acetate, terpineol, turpentine, butyl carbitol, isopropyl alcohol, or a combination thereof, The above binder is an acrylic binder or a nitrocellulose binder, A glass substrate for semiconductors, wherein the additive is one selected from the group consisting of glycerin, polyethylene glycol (PEG), glass powder, or a combination thereof. In paragraph 11, A semiconductor glass substrate, wherein the electrode reacts with the bonding metal layer to form a eutectic bond. In paragraph 11, The above glass core, A semiconductor glass substrate made of oxide-reinforced glass with a thickness of 20 to 30 μm and high strength, corrosion resistance, transparency, and hardness at room temperature. In paragraph 16, The above glass core is a semiconductor glass substrate made of borosilicate glass or aluminosilicate glass.

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