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

Abstract

Disclosed are a method for manufacturing a multilayer glass substrate for a semiconductor and a multilayer glass substrate for a semiconductor. The disclosed method for manufacturing a multilayer glass substrate for a semiconductor comprises the steps of: forming a bonding glass layer by applying a glass frit paste to the surface of a glass core and then performing primary pre-sintering; disposing another glass core on the glass core so as to face each other with the bonding glass layer interposed therebetween; and hermetically bond two stacked glass cores by performing secondary main sintering of the bonding glass layer in a vacuum atmosphere.

Description

Method for manufacturing a multilayer glass substrate for semiconductors and a multilayer glass substrate for semiconductors

[0001] The present invention relates to a method for manufacturing a glass substrate, and more particularly, to a method for manufacturing a multilayer glass substrate for semiconductors in which two or more glass substrates are laminated and bonded, and a multilayer 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, in the case of glass substrates, due to the material properties, there is a disadvantage that interlayer bonding is not easy when manufacturing in the form of a multilayer glass substrate using two or more layers, and when general bonding materials are used for interlayer bonding of glass substrates, interlayer separation occurs due to differences in coefficients of thermal expansion between the bonding material and the glass, causing problems with bonding reliability.

[0008] The technical problem to be solved by the present invention is to provide a method for manufacturing a multilayer glass substrate for semiconductors and a multilayer glass substrate for semiconductors that can resolve the problem of interlayer separation due to a difference in thermal expansion coefficient between a bonding material and glass during the manufacturing of a multilayer glass substrate.

[0009] According to one aspect of the present invention as a means of solving the problem,

[0010] (a) A step of forming a bonding glass layer by applying glass frit paste to the surface of a glass core and then performing a first pre-sintering;

[0011] (b) placing another glass core on top of the glass core so that they face each other with a bonding glass layer therebetween; and

[0012] (c) A method for manufacturing a multilayer glass substrate for semiconductors is provided, including a step of sealing and bonding two glass cores arranged in a laminate by performing secondary sintering (main-sintering) of the bonding glass layer in a vacuum atmosphere.

[0013] In a method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention, the bonding glass layer may include glass frit having a melting point lower than that of the glass core.

[0014] In a method for manufacturing a multilayer glass substrate for semiconductors 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 high strength, corrosion resistance, transparency, and hardness at room temperature.

[0015] In a method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention, the glass core may be borosilicate glass or aluminosilicate glass.

[0016] In the step (a) of the method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention, the glass frit paste can be applied to the surface of the glass core at a uniform thickness using screen printing.

[0017] A method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention also comprises:

[0018] (a') The method may further include a step of forming a trench electrode in the glass core prior to the step (a).

[0019] The step (a') of the method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention may include the steps of (a'-1) forming a trench in the glass core through etching, (a'-2) forming a brazing adhesive layer with a specific thickness on an inner wall surface of the trench using a brazing alloy having a lower melting point than the glass core, (a'-3) filling the trench in which the brazing adhesive layer is formed with a conductive metal having a higher melting point than the brazing alloy to form an electrode, and (a'-4) performing a heat treatment under specific conditions so that the brazing adhesive layer mediates mutual bonding between the glass core and the electrode.

[0020] In the method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention, in (a'-4), heat treatment may be performed in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range that is higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core.

[0021] Here, the first temperature range may be 577°C or more and less than 600°C.

[0022] In a method for manufacturing a multilayer glass substrate for semiconductors according to one aspect of the present invention, the brazing alloy may be an aluminum-silicon (Al-Si) alloy in which the silicon (Si) content is 12.5 to 12.6 parts by weight (%) based on 100 parts by weight (%) of the total alloy and the remainder is aluminum.

[0023] According to another aspect of the present invention as a means of solving the problem,

[0024] Two or more glass cores arranged in a laminated manner; and

[0025] A bonding glass layer mediating a hermetic bond between two adjacent glass cores;

[0026] The above bonding glass layer provides a multilayer glass substrate for semiconductors, which includes a glass frit having a lower melting point than the glass core.

[0027] In a multilayer organic semiconductor substrate according to another aspect of the present invention, the glass core may include a trench electrode.

[0028] In another aspect of the present invention, in a multilayer organic substrate for semiconductors, a brazing bonding layer made of a brazing alloy is formed with a specific thickness between the inner wall surface of a trench constituting the trench electrode and a conductive metal, and the brazing bonding layer can form a fusion brazing interface that mediates mutual bonding between the inner wall surface of the trench and the conductive metal during heat treatment.

[0029] In a multilayer organic plate for semiconductors according to another aspect of the present invention, the brazing alloy is an aluminum-silicon (Al-Si) alloy in which the silicon (Si) content is 12.5 to 12.6 parts by weight (%) and the remainder is aluminum, based on 100 parts by weight (%) of the total alloy, and the conductive metal may be copper (Cu).

[0030] Here, the fusion brazing interface can be formed by heat treatment performed in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range that is higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core, and at this time, the first temperature range can be 577°C or more and less than 600°C.

[0031] In a multilayer glass substrate for semiconductors 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.

[0032] In a multilayer glass substrate for semiconductors according to another aspect of the present invention, the glass core may be borosilicate glass or aluminosilicate glass.

[0033] In a multilayer glass substrate for semiconductors according to another aspect of the present invention, the bonding glass layer can be formed by pre-sintering performed after applying glass frit paste to the surface of a glass core.

[0034] According to the present invention, when manufacturing a multilayer glass substrate, a glass material having a lower melting point than the glass core, which is the core substrate, is used to implement multilayer bonding, thereby enabling the coefficients of thermal expansion (CTE) of the glass core and the bonding layer to be matched. As a result, the problem of interlayer separation due to differences in the coefficients of thermal expansion can be clearly resolved, and a highly reliable multilayer glass substrate with further improved bonding reliability between glass cores (glass substrates) can be provided.

[0035] In addition, by forming a brazing adhesive layer in a trench of a glass core and filling it with a conductive metal to form an electrode and then performing heat treatment under specific conditions, the fusion brazing interface caused by the phase change (solid -> liquid) of the brazing adhesive layer occurring during the heat treatment process can mediate a strong bond between the glass core and the electrode, thereby significantly improving or enhancing the adhesive strength (bonding strength) and adhesive properties of the electrode.

[0036] FIG. 1 is a flowchart illustrating a method for manufacturing a multilayer glass substrate for semiconductors according to an embodiment of the present invention.

[0037] FIG. 2 is a process schematic diagram schematically illustrating the overall manufacturing process of a multilayer glass substrate for semiconductors according to an embodiment of the present invention.

[0038] Figure 3 is a flowchart sequentially illustrating the process of forming a trench electrode in a glass core.

[0039] Figure 4 is a process schematic diagram schematically illustrating the trench electrode formation process of Figure 3.

[0040] FIG. 5 is a cross-sectional configuration diagram of a multilayer glass substrate for semiconductors manufactured by a method for manufacturing a multilayer glass substrate for semiconductors according to an embodiment of the present invention.

[0041] FIG. 6 is an enlarged view of the main part of the multilayer glass substrate for semiconductors 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.

[0042] Fig. 7 is a cross-sectional view showing another preferred embodiment of a multilayer glass substrate for semiconductors.

[0043] Fig. 8 is a cross-sectional view showing another preferred embodiment of a multilayer glass substrate for semiconductors.

[0044] Hereinafter, preferred embodiments of the present invention will be described in detail.

[0045] 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.

[0046] 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.

[0047] Additionally, terms including ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by the terms. The terms are used only for the purpose of distinguishing one component from another.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] And when a component is said to be “in front”, “behind”, “above” or “below” another component, unless there are special circumstances, it includes not only being placed “in front”, “behind”, “above” or “below” the other component in direct contact with it, but also cases where another component is placed in between.

[0052] 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.

[0053] FIG. 1 is a flowchart for explaining a method for manufacturing a multilayer glass substrate for semiconductors according to an embodiment of the present invention, and FIG. 2 is a process schematic diagram schematically illustrating the entire manufacturing process of a multilayer glass substrate for semiconductors according to an embodiment of the present invention.

[0054] Referring to FIGS. 1 and 2, a manufacturing method according to an embodiment is a method for manufacturing a semiconductor multilayer glass substrate that can significantly improve interlayer bonding when manufacturing a multilayer glass substrate, including a step of forming a bonding glass layer on a surface of a glass core (S200), a step of stacking and arranging another glass core on a glass core on which a bonding glass layer has been formed (S300), and a step of sealing and bonding the two stacked glass cores (S300).

[0055] In the step (S100) of forming a bonding glass layer on the surface of the glass core, glass frit paste is applied to the surface (upper surface or lower surface or upper surface and lower surface) of the glass core (10). Afterwards, a bonding glass layer (20) can be formed by performing a first pre-sintering. In the step (S100) of forming a bonding glass layer on the surface of the glass core, the bonding glass layer (20) includes glass frit having a melting point about 100°C lower than that of the glass core (10).

[0056] In the step (S100) of forming a bonding glass layer on the surface of the glass core, the glass frit paste can be formed with a uniform film thickness on the surface of the glass core (10). If the film thickness of the glass frit paste applied to the surface of the glass core (10) is not uniform, when a pair of glass cores (10a, 10b) are overlapped, the contact uniformity between the bonding glass layer (20) and the glass cores (10a, 10b) may deteriorate, and the bonding quality between the glass cores (10a, 10b) may be significantly deteriorated.

[0057] Therefore, in the step (S100) of forming a bonding glass layer on the surface of the glass core, when applying the glass frit paste to the surface of the glass core (10), it is important and required to apply the glass frit paste so that it has a uniform film thickness on the glass core (10). The uniform film thickness application of the glass frit paste can be achieved, for example, by screen printing.

[0058] In the step (S100) of forming a bonding glass layer on the surface of the glass core, the glass frit paste applied to the glass core (10) may have a composition that includes glass frit having a melting point about 100°C lower than the melting point of the glass core (10) as a main substrate and an organic solvent and a binder, and the bonding glass layer (20) may be formed by removing the organic solvent or binder included in the glass frit paste during the first pre-sintering process.

[0059] Glass frit can be, for example, a mixture of silica sand, aluminum oxide (Al2O3), and calcium carbonate (CaCO3) in a specific ratio, melted at high temperature, then rapidly cooled and ground into a fine powder. The organic solvent can be, for example, butyl acetate or terpineol, or a combination thereof, and an acrylic binder or nitrocellulose binder can be used as a binder.

[0060] If the heating of the glass frit paste is not sufficient during the first pre-sintering process, the binder may remain within the bonding glass layer (20), which may result in poor bonding performance or easy cracking. Therefore, during the first pre-sintering process, it is preferable to perform the pre-sintering under temperature and pressure conditions that can sufficiently heat the glass frit paste while preventing deterioration of the glass core (10).

[0061] A drying step (not shown) may be added after the first preliminary sintering step to dry the glass frit paste. By performing an additional drying step after the first preliminary sintering step, any organic solvent remaining within the glass frit paste can be more reliably removed. In the drying step, it is preferable to perform the drying step at a temperature and time that allows the organic solvent to be vaporized and removed while also allowing the high-temperature glass frit paste to be slowly cooled.

[0062] In the step (S200) of stacking and arranging glass cores, two glass cores (10a, 10b) of the same material are arranged in a stacked structure so that they face each other and come into contact with each other with a bonding glass layer (20) therebetween. Considering that the alignment of the stacking direction of the glass cores (10a, 10b) during the stacking process has a significant influence on the bonding quality in the subsequent sealing and bonding step, it is preferable to use a dedicated stacking device including a sensor, an alignment unit, a jig, etc. to enable accurate and precise stacking.

[0063] In the step (S300) of sealing and bonding the laminated glass cores, a process of implementing laminated bonding can be performed through secondary sintering (main-sinter) of the bonding glass layer (20). In the step (S300) of sealing and bonding the laminated glass cores, preferably, the sealing and bonding of the glass cores (10a, 10b) can be implemented by heating and compressing the bonding glass layer (20) while exhausting the gas between the two laminated glass cores (10a, 10b) in a vacuum atmosphere.

[0064] In the secondary sintering (main sinter) of heating and pressing the bonding glass layer (20), sintering can be performed at a temperature lower than the melting point and higher than the softening point of the glass frit, which is the main material of the bonding glass layer (20). In the embodiment, the secondary sintering temperature for implementing a sealing bond of the glass cores (10a, 10b) may vary depending on the composition of the glass frit, but may be between about 500°C and 700°C.

[0065] In the method for manufacturing a semiconductor multilayer glass substrate according to an embodiment, the glass core (10) that is the main material may be oxide-tempered glass. In the method for manufacturing a semiconductor multilayer glass substrate according to an embodiment, the glass core (10) that is the main material may be tempered glass whose main component is oxide, having a thickness of 20 to 30 ㎛, and having high strength and corrosion resistance at room temperature, as well as transparency and hardness.

[0066] As a preferred example, the glass core (10) that is the main material in the method for manufacturing a semiconductor multilayer glass substrate according to the embodiment may be borosilicate glass, which 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.

[0067] As another preferred example, the glass core (10) that is the main material in the method for manufacturing a semiconductor multilayer 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.

[0068] The method for manufacturing a multilayer glass substrate for semiconductors according to an embodiment may further include a step (S100) of forming a trench electrode in a glass core (10) before the step S200 described above. In the step (S100) of forming a trench electrode in a glass core, the trench electrode (30) may be formed by etching the glass core (10) to form a trench (Trench, 32) in a desired pattern and filling it with a conductive metal, for example, copper (Cu).

[0069] Let us look more specifically at the process of forming electrodes on a glass core with reference to FIGS. 3 and 4.

[0070] Fig. 3 is a flowchart sequentially illustrating a process for forming a trench electrode in a glass core, and Fig. 4 is a process schematic diagram schematically illustrating the trench electrode forming process of Fig. 3.

[0071] For reference, the term 'trench' used in describing the electrode formation process hereafter refers to a microscopic hole (Via) or groove formed in the glass core through an etching process to form an electrode.

[0072] Referring to FIGS. 3 and 4, the trench electrode forming step (100) includes a step (S102) of forming a trench (32) in a glass core (10) through an etching process, a step (S104) of forming a brazing adhesive layer (34) with a specific thickness on the inner wall surface of the trench (32) using a brazing alloy having a lower melting point than the glass core (10), a step (S106) of filling the trench (32) in which the brazing adhesive layer (34) is formed with a conductive metal (36) to form an electrode, and a step (S108) of performing heat treatment for brazing.

[0073] In the step (S102) of forming a trench in a glass core, a pattern is formed on the glass core (10) using a photoresist through a known photolithography process for drawing a semiconductor circuit on a wafer, and an etching process is performed using the patterned photoresist as a mask to form a trench (32). Dry etching using plasma or a laser or wet etching using an etchant can be applied as the etching process for forming the trench.

[0074] The step (S104) of forming a brazing adhesive layer (34) is a step of forming a brazing adhesive layer (34) on the inner wall surface of the trench (32) using a brazing alloy. In the step (S104) of forming a brazing adhesive layer (34), the brazing adhesive layer (34) is a portion that mediates a strong bond between the glass core (10) and the conductive metal (36), and can be formed by depositing a brazing alloy to a specific thickness in the trench (32) formed in the glass core (10).

[0075] In the step (S104) of forming a brazing bonding layer (34), the brazing alloy constituting the brazing bonding layer (34) may be an alloy having a lower melting point than the glass core (10). The brazing alloy constituting the brazing bonding layer (34) may preferably be an aluminum-silicon (Al-Si) alloy having a silicon (Si) content of 12.5 to 12.6 parts by weight (%) based on 100 parts by weight (%) of the total alloy and the remainder being aluminum.

[0076] Aluminum-silicon (Al-Si) alloys are characterized by their light weight, high ductility, and high malleability. They also possess a low melting point and shrinkage, excellent corrosion resistance, and good fluidity in a molten state. Therefore, they readily melt at relatively low temperatures, forming a fusion brazing interface between glass and metal, mediating a strong bond between them.

[0077] In the step (S104) of forming a brazing adhesive layer (34), the brazing adhesive layer (34) can be formed to a specific thickness in the trench of the glass core (10) through vacuum deposition. In the step (S104) of forming a brazing adhesive layer (34), the brazing adhesive layer (34) can be formed to a specific thickness (t1) in the trench of the glass core (10) through a sputtering process, which is a type of vacuum deposition method.

[0078] In the step (S104) of forming a brazing adhesive layer (34), the brazing adhesive layer (34) may be formed on the inner wall surface of the trench to a thickness of 25 to 100 nm. If the thickness of the brazing adhesive layer (34) is too thin, less than 25 nm, it cannot properly function as an adhesive. In addition, if the thickness of the brazing adhesive layer (34) exceeds 100 nm, an increase in cost may occur due to the input of unnecessary materials, and the electrode formation space may be reduced.

[0079] In the step of forming an electrode (S106), the electrode may be composed of a conductive metal (36) having a higher melting point than the brazing alloy constituting the brazing adhesive layer (34). In the step of forming an electrode (S106), the electrode may be formed by filling a trench (32) on the inner wall of which a brazing adhesive layer (34) is formed with a conductive metal (36) through an electroplating process or a sputtering process, which is a type of vacuum deposition.

[0080] In the step of forming an electrode (S106), the conductive metal (36) constituting the electrode may be, for example, copper (Cu). In the step of forming an electrode (S106), the conductive metal (36) constituting the electrode may be a conductive material other than copper. In the step of forming an electrode (S106), the conductive metal constituting the electrode (36) may be, for example, one of aluminum (Al), titanium (Ti), and tungsten (W).

[0081] The heat treatment step (S108) is the final step of the trench electrode formation process, and is a step of brazing and joining the electrode by heat treating the glass core (10) on which the electrode is formed under predetermined conditions. In the heat treatment step (S108), the heat treatment is performed at a temperature higher than the melting point of the aforementioned brazing alloy and lower than the melting point of the glass core (10), thereby allowing the brazing adhesive layer (34) to mediate a strong bond between the glass core (10) and the electrode composed of the conductive metal (36).

[0082] In the heat treatment step (S108) for brazing, the heat treatment may be performed in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range that is higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core (10). In the embodiment, the first temperature range is preferably 577°C or more and less than 600°C, considering that the eutectic temperature of an aluminum-silicon alloy having a silicon (Si) content of 12.5% ​​is 577°C.

[0083] The phase change (solid -> liquid) of the brazing adhesive layer (34) occurs by the above heat treatment performed above the eutectic point of the brazing alloy, and a fusion brazing interface that mediates a strong bond between the glass core (10) and the electrode is formed according to the phase change of the brazing adhesive layer (34), so that the electrode made of the conductive metal (36) and the trench (32) formed in the glass core (10) can form a strong bond with each other.

[0084] Meanwhile, in the case of a glass core (10) having a trench electrode (30), when forming a bonding glass layer (20) on the surface of the glass core (10) (e.g., the upper surface, lower surface, or both surfaces of the glass core (10)) in the above-described step S200, it is preferable to form the bonding glass layer (20) only in an area excluding the portion of the trench electrode (30a) where the fine hole is formed so that the trench electrode (through electrode, 30a) formed in the fine hole among the trench electrodes (30) mediates electrical connection between layers when bonding the glass core (10).

[0085] According to the manufacturing method discussed above, when manufacturing a multilayer glass substrate, a glass material having a lower melting point than the glass core, which is the core substrate, can be used to achieve multilayer bonding, thereby matching the coefficients of thermal expansion (CTE) of the glass core and the bonding layer. Accordingly, the problem of interlayer separation due to differences in thermal expansion coefficients can be clearly resolved, and a highly reliable multilayer glass substrate with improved interlayer bonding characteristics between glass cores (glass substrates) can be provided.

[0086] In addition, by forming a brazing adhesive layer in a trench of a glass core and filling it with a conductive metal to form an electrode and then performing heat treatment under specific conditions, the fusion brazing interface caused by the phase change (solid -> liquid) of the brazing adhesive layer occurring during the heat treatment process can mediate a strong bond between the glass core and the electrode, thereby significantly improving or enhancing the adhesive strength (bonding strength) and adhesive properties of the electrode.

[0087] FIG. 5 is a cross-sectional view of a multilayer glass substrate for semiconductors manufactured by the method for manufacturing a multilayer glass substrate for semiconductors described above, and FIG. 6 is an enlarged view of the main part of the multilayer glass substrate for semiconductors shown in FIG. 5, and is an enlarged view of the main part of the present invention showing part 'A' of FIG. 5.

[0088] Referring to FIGS. 5 and 6, a multilayer glass substrate (1) for semiconductors includes two or more glass cores (10a, 10b) arranged in a stacked manner and a bonding glass layer (20) that mediates a sealing bond between two adjacent glass cores (10a, 10b). A trench electrode (30) may be formed in the glass cores (10a, 10b), and the bonding glass layer (20) may be formed on at least one of the upper and lower surfaces of the glass cores (10a, 10b) for sealing the bonding between the glass cores (10a, 10b).

[0089] 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.

[0090] 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.

[0091] A trench electrode (30) can be formed by filling a trench (32) formed in the shape of a groove or hole in a glass core (10) through an etching process with a conductive metal (36). To ensure strong bonding between the trench (32) and the conductive (36) metal, a brazing adhesive layer (34) made of a brazing alloy can be formed with a specific thickness (t1) between the inner wall surface of the trench (32) and the conductive metal (36). The brazing adhesive layer (34) can preferably be formed with a thickness of 25 to 100 nm.

[0092] The brazing adhesive layer (34) can form a fusion brazing interface that mediates a strong bond between the inner wall surface of the trench (32) formed in the glass core (10) during heat treatment for brazing bonding and the conductive metal (36) filled in the trench (32). The brazing adhesive layer (34) can be formed on the inner wall surface of the trench, for example, through a sputtering process, which is a type of vacuum deposition method.

[0093] The brazing alloy constituting the brazing bonding layer (34) may be an alloy having a lower melting point than the glass core (10). The brazing alloy constituting the brazing bonding layer (34) may preferably be an aluminum-silicon (Al-Si) alloy having a silicon (Si) content of 12.5 to 12.6 parts by weight (%) based on 100 parts by weight (%) of the total alloy and the remainder being aluminum (Al), but is not limited thereto.

[0094] Aluminum-silicon (Al-Si) alloys are characterized by their light weight, high ductility, and high malleability. They also possess a low melting point and shrinkage, excellent corrosion resistance, and good fluidity in a molten state. Therefore, they readily melt at relatively low temperatures, forming a fusion brazing interface between glass and metal, mediating a strong bond between them.

[0095] The fusion brazing interface can be formed by performing a heat treatment in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range that is higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core (10). In an embodiment, the first temperature range may be 577°C or more and less than 600°C, considering that the eutectic temperature of an aluminum-silicon alloy having a silicon (Si) content of 12.5% ​​is 577°C.

[0096] The conductive metal (36) constituting the trench electrode (30) may be a conductive material having a higher melting point than the glass core (10). The conductive metal (36) constituting the trench electrode (30) may preferably be copper (Cu). The conductive metal (36) constituting the trench electrode (30) may be a conductive material other than copper. For example, aluminum (Al), titanium (Ti), tungsten (W), etc. may be used as the conductive metal constituting the trench electrode (30).

[0097] The bonding glass layer (20) can be formed on the surface (upper surface, lower surface, or upper surface and lower surface) of the glass core (10) by applying glass frit paste and then pre-sintering. The bonding glass layer (20) includes glass frit having a melting point about 100°C lower than that of the glass core (10), and can be formed with a uniform film thickness on the surface of the glass core (10). For example, it can be formed with a uniform film thickness on the surface of the glass core (10) through screen printing.

[0098] The glass frit paste applied to the glass core (10) to form the bonding glass layer (20) may be composed of the glass frit having a melting point about 100°C lower than the melting point of the glass core (10) as a main substrate and including an organic solvent and a binder, and the bonding glass layer (20) may be formed by removing the organic solvent or binder included in the glass frit paste during the pre-sintering process.

[0099] Glass frit can be, for example, a mixture of silica sand, aluminum oxide (Al2O3), and calcium carbonate (CaCO3) in a specific ratio, melted at high temperature, then rapidly cooled and ground into a fine powder. The organic solvent can be, for example, butyl acetate or terpineol, or a combination thereof, and an acrylic binder or nitrocellulose binder can be used as a binder.

[0100] Meanwhile, the electrode may be formed in a relief shape on one or both sides of the glass core, in addition to the trench electrode shape described above. For example, as in another embodiment illustrated in FIG. 7, it may be formed in relief on the upper surface of the glass core (10'). The relief protruding electrode (30') may be formed by a method such as brazing a metal foil to the upper surface of the glass core (10') and then removing unnecessary metal foil portions through an etching process or the like.

[0101] When forming a protruding electrode (30') on the upper surface of the glass core (10'), the bonding glass layer (20') can be formed with a predetermined thickness on the upper surface of the glass core (10') in a form that covers both the upper surface of the glass core (10') and the protruding electrode (30'), as shown in FIG. 7.

[0102] However, in this case, in order to electrically connect the two glass cores (10a', 10b') when bonding the glass cores, the bonding glass layer (20) may be formed with a predetermined thickness only in the area excluding the electrode (through electrode, 30a') formed in the micro-hole.

[0103] In some cases, as in another embodiment of FIG. 8, a bonding glass layer (20") may be first formed on the upper surface of a glass core (10"), and an electrode may be formed in the form of a raised protruding electrode (30") on the bonding glass layer (20"). In this case, the raised protruding electrode (30") may be formed, for example, by brazing a metal foil to the upper surface of the bonding glass layer (20"), and then removing an unnecessary portion of the metal foil through an etching process or the like.

[0104] According to the multilayer glass substrate for semiconductors according to the above embodiment, the glass-based bonding layer having a lower melting point than the glass core, which is the core substrate, mediates bonding between the two glass cores to be bonded, thereby matching the coefficients of thermal expansion (CTE) of the glass core and the bonding layer. Accordingly, the problem of interlayer separation due to differences in thermal expansion coefficients can be clearly resolved, and the bonding reliability between glass cores (glass substrates) can be further improved.

[0105] 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.

[0106] 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

1. (a) A step of forming a bonding glass layer by applying glass frit paste to the surface of a glass core and then performing a first pre-sintering; (b) placing another glass core on top of the glass core so that they face each other with a bonding glass layer therebetween; and (c) A method for manufacturing a multilayer glass substrate for semiconductors, comprising a step of sealing and bonding two glass cores arranged in a laminate by performing secondary sintering (main-sintering) of the bonding glass layer in a vacuum atmosphere.

2. In paragraph 1, A method for manufacturing a multilayer glass substrate for semiconductors, wherein the bonding glass layer includes glass frit having a lower melting point than the glass core.

3. In paragraph 1, The above glass core, A method for manufacturing a multilayer glass substrate for semiconductors, which is an oxide-reinforced glass having a thickness of 20 to 30 μm and high strength, corrosion resistance, transparency, and hardness at room temperature.

4. In paragraph 3, The above glass core, A method for manufacturing a multilayer glass substrate for semiconductors, which is made of borosilicate glass or aluminosilicate glass.

5. In paragraph 1, In the above step (a), A method for manufacturing a multilayer glass substrate for semiconductors, wherein the glass frit paste is applied to the surface of the glass core with a uniform thickness by screen printing.

6. In paragraph 1, (a') A method for manufacturing a multilayer glass substrate for semiconductors, further comprising a step of forming a trench electrode in the glass core prior to step (a).

7. In paragraph 6, The above step (a') is, (a'-1) A step of forming a trench in the glass core through etching; (a'-2) A step of forming a brazing adhesive layer with a specific thickness on the inner wall surface of the trench using a brazing alloy having a lower melting point than the glass core; (a'-3) a step of forming an electrode by filling a conductive metal having a higher melting point than the brazing alloy in the trench where the brazing adhesive layer is formed; and (a'-4) A method for manufacturing a multilayer glass substrate for semiconductors, comprising: a step of performing heat treatment under specific conditions so that the brazing adhesive layer mediates mutual bonding between the glass core and the electrode.

8. In paragraph 7, In the above step (a'-4), A method for manufacturing a multilayer glass substrate for semiconductors, wherein heat treatment is performed in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core.

9. In paragraph 7, A method for manufacturing a multilayer glass substrate for semiconductors, wherein the first temperature range is 577°C or more and less than 600°C.

10. In paragraph 7 or 8, A method for manufacturing a multilayer glass substrate for semiconductors, wherein the brazing alloy is an aluminum-silicon (Al-Si) alloy having a silicon (Si) content of 12.5 to 12.6 parts by weight (%) based on 100 parts by weight (%) of the total alloy and the remainder being aluminum.

11. Two or more glass cores arranged in a laminated manner; and A bonding glass layer mediating a hermetic bond between two adjacent glass cores; A multilayer glass substrate for semiconductors, wherein the bonding glass layer includes glass frit having a lower melting point than the glass core.

12. In paragraph 11, The above glass core is a multilayer glass substrate for semiconductors, including a trench electrode.

13. In paragraph 12, A brazing bonding layer made of a brazing alloy is formed with a specific thickness between the inner wall surface of the trench constituting the trench electrode and the conductive metal, A multilayer glass substrate for semiconductors, wherein the brazing adhesive layer forms a fusion brazing interface that mediates mutual bonding between the inner wall surface of the trench and the conductive metal during heat treatment.

14. In paragraph 13, A multilayer glass substrate for semiconductors, wherein the brazing alloy is an aluminum-silicon (Al-Si) alloy in which the silicon (Si) content is 12.5 to 12.6 parts by weight (%) based on 100 parts by weight (%) of the total alloy and the remainder is aluminum, and the conductive metal is copper (Cu).

15. In paragraph 13, A multilayer glass substrate for semiconductors, wherein the fusion brazing interface is formed by heat treatment performed in a reducing atmosphere or nitrogen atmosphere maintained at a first temperature range higher than the eutectic point of the brazing alloy and lower than the melting point of the glass core.

16. In paragraph 15, A multilayer glass substrate for semiconductors, wherein the first temperature range is 577°C or more and less than 600°C.

17. 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.

18. In paragraph 17, The above glass core, A multilayer glass substrate for semiconductors, made of borosilicate glass or aluminosilicate glass.

19. In paragraph 11, The above bonding glass layer, A multilayer glass substrate for semiconductors formed by applying glass frit paste to the surface of a glass core and then pre-sintering.

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