Perforated glass substrate, glass substrate, method for producing perforated glass substrate, and method for producing glass substrate

Abstract

The present invention addresses the problem of providing: a glass substrate which is suitable for the formation of a hole that has a closely straight shape; and a method for producing a glass substrate. A glass substrate G1, G2 according to the present invention comprises: a first main surface G1a, G2a; a second main surface G1b, G2b that is on the reverse side from the first main surface G1a, G2a; and a hole 1, 2. The glass substrate G1, G2 is characterized in that: the hole 1, 2 comprises a non-through hole 2 that is formed in one main surface of the first main surface G1a, G2a and the second main surface G1b, G2b, and / or a through hole 1 that penetrates the glass substrate between the first main surface G1a, G2a and the second main surface G1b, G2b; and when ER is the HF etching rate of the glass substrate G1, G2 and ERa is the HF etching rate of the glass substrate G1, G2 after a heat treatment, ER / ERa is not less than 0.2 but less than 1.

Description

Perforated glass substrate, glass substrate, method for manufacturing a perforated glass substrate, and method for manufacturing a glass substrate

[0001] The present invention relates to a glass substrate for semiconductor packaging, a method for manufacturing a glass substrate for semiconductor packaging, a perforated glass substrate for semiconductor packaging, and a method for manufacturing a glass substrate for semiconductor packaging.

[0002] Development is underway for semiconductor package substrates that mount multiple semiconductor elements on a single electronic substrate (core substrate). Glass has excellent dimensional stability and low dielectric properties. Therefore, using glass as the material for the core substrate or the interposer that connects the semiconductor elements to the core substrate can improve the performance of the semiconductor package substrate. When using a glass substrate as a glass core substrate or glass interposer, it is necessary to form through electrodes to make the front and back surfaces of the glass substrate electrically conductive. These through electrodes are formed by creating fine through holes and filling the inside of the through holes with a conductive material.

[0003] A known method for accurately forming through-holes in a glass substrate involves irradiating the glass substrate with a pulsed laser to create a modified area where the through-hole is to be formed, and then etching the modified area off the glass substrate to form the through-hole. Through-holes formed by this method have a tapered shape, but for high-density semiconductor mounting, it is preferable that the diameter of the through-hole on the glass surface is small, that is, that the taper angle of the through-hole is small and it is close to a straight shape.

[0004] Patent Document 1 discloses that if the HF etching rate of the glass substrate before heat treatment is ER and the HF etching rate of the glass substrate after heat treatment is ERa, then if ER / ERa is 1.5 or less and the glass substrate is alkali-free glass, then when forming through holes in the glass substrate using the method described above, the taper angle of the through holes can be reduced.

[0005] International Publication No. 2022 / 196510

[0006] When using a glass substrate as a core substrate or interposer, a predetermined heat treatment such as annealing may be performed to reduce the difference between the maximum and minimum distances between the first and second main surfaces of the glass substrate (TTV = Total Thickness Variation) and warping. As disclosed in Patent Document 1, when forming through holes in alkali-free glass, the HF etching rate can be lowered by performing a predetermined heat treatment on the glass substrate, thereby reducing the taper angle of the through hole. On the other hand, depending on the glass composition, the HF etching rate may increase after heat treatment, making it impossible to reduce the taper angle of the through hole. In particular, borosilicate glass has a low HF etching rate, making it easy to form through holes that are close to straight, but it is also a composition that is prone to phase separation. For this reason, when a glass substrate using borosilicate glass is heat-treated, phase separation may progress, and the HF etching rate may increase.

[0007] In addition, non-through holes may be formed in the glass substrate instead of through holes. In this case as well, heat treatment of a glass substrate using borosilicate glass tends to increase the HF etching rate.

[0008] In view of the above issues, the present invention aims to form holes that are close to a straight shape even in a glass substrate made of borosilicate glass.

[0009] As a result of repeated experiments, the inventors of the present invention have found that the above technical problems can be solved by strictly controlling the glass composition of the glass substrate and by controlling the ratio of the etching rate before heat treatment to the etching rate after heat treatment to a predetermined range.

[0010] (1) The porous glass substrate for a semiconductor package of the present invention devised based on the above findings is a porous glass substrate including a first main surface, a second main surface opposite to the first main surface, and holes, where the holes include non-through holes formed on one of the first main surface and the second main surface, and / or through holes penetrating between the first main surface and the second main surface. When the HF etching rate of the porous glass substrate is ER and the HF etching rate after heat-treating the porous glass substrate is ERa, it is characterized in that ER / ERa is 0.2 or more and less than 1.

[0011] (2) In the configuration of (1) above, as the glass composition, in mol%, SiO ２ 65 to 85%, Al ２ O ３ 0 to 10%, B ２ O ３ 1 to 20%, Li ２ O 0 to 3%, Na ２ O 1 to 20%, K ２ O 0 to 5% is preferably contained.

[0012] (3) In the configuration of (1) or (2) above, the HF etching rate ER of the porous glass substrate is preferably 0.65 μm / min or less.

[0013] (4) In any of the configurations of (1) to (3) above, the average thermal expansion coefficient in the temperature range of 30 to 380°C is preferably 20×10 －７ to 80×10 －７ / °C.

[0014] (5) In any of the configurations of (1) to (4) above, the side surface of the hole is inclined with respect to the plate thickness direction, and the average taper angle of the side surface is preferably more than 0° and 4° or less.

[0015] (6) In any of the configurations of (1) to (5) above, the diameter of the hole on the main surface is preferably 5 μm or more and 200 μm or less.

[0016] (7) In any of the configurations (1) to (6) above, the hole is provided with the through hole, and the through hole has a constricted portion in the center of the thickness direction of the glass substrate, the constricted portion having a smaller diameter than the diameter of the through hole on the first main surface and the second main surface, and the diameter of the constricted portion is preferably 5% or more and 99% or less of the diameter of the through hole on the first main surface and the diameter of the through hole on the second main surface.

[0017] (8) In any of the configurations (1) to (7) above, it is preferable that the side surface of the hole is an etched surface.

[0018] (9) The semiconductor package glass substrate of the present invention, which was devised based on the above findings, is a semiconductor package glass substrate used in the manufacture of a perforated glass substrate for semiconductor packaging, and is characterized in that when the HF etching rate of the glass substrate is ER and the HF etching rate after heat treatment of the glass substrate is ERa, ER / ERa is 0.2 or more and less than 1.

[0019] (10) In the configuration of (9) above, the glass composition is SiO in mol% ２ 65-85%, Al ２ O ３ 0-10%, B ２ O ３ 1-20%, Li ２ O 0-3%, Na ２ O 1-20%, K ２ It is preferable that it contains 0-5% of O.

[0020] (11) A method for manufacturing a perforated glass substrate for semiconductor packaging, devised based on the above findings, is characterized by comprising: a preparation step of preparing a glass substrate having the configuration of (9) or (10) above; a laser irradiation step of irradiating the portion of the glass substrate where holes are to be formed with laser light to form a modified portion; and an etching step of etching the glass substrate having the modified portion to form holes.

[0021] (12) Another aspect of the method for manufacturing a perforated glass substrate for semiconductor packaging of the present invention, which was devised based on the above findings, is a method for manufacturing a perforated glass substrate for semiconductor packaging, comprising: a preparation step of preparing a glass substrate; a laser irradiation step of irradiating the portion of the glass substrate where holes are to be formed with laser light to form a modified portion; and an etching step of etching the glass substrate having the modified portion to form holes, wherein the preparation step comprises a molding step of forming the glass substrate from molten glass; and a cooling step of cooling the molded glass substrate, characterized in that the average cooling rate in the temperature range of (strain point Ps - 10°C) to (slow cooling point Ta + 200°C) is 1°C / second or more.

[0022] (13) Another aspect of the method for manufacturing a perforated glass substrate for semiconductor packaging of the present invention, which was devised based on the above findings, is a method for manufacturing a glass substrate for semiconductor packaging comprising a molding step of forming a glass substrate from molten glass and a cooling step of cooling the molded glass substrate, wherein in the cooling step, the average cooling rate in the temperature range of (strain point Ps - 10°C) to (slow cooling point Ta + 200°C) is 1°C / second or more.

[0023] According to the present invention, even with a glass substrate made of borosilicate glass, it is possible to form holes that are close to a straight shape.

[0024] Figure 1 is a schematic diagram showing the temperature profile when heat-treating a glass substrate according to one embodiment of the present invention. Figure 2 is a flow diagram showing a method for manufacturing a glass substrate according to one embodiment of the present invention. Figure 3 is a top view showing a glass substrate with through holes according to one embodiment of the present invention. Figure 4 is a cross-sectional view taken along line A-A of the glass substrate in Figure 3. Figure 5 is a schematic cross-sectional view showing a first example of a through hole formed in a glass substrate according to one embodiment of the present invention. Figure 6 is a schematic cross-sectional view showing a second example of a through hole formed in a glass substrate according to one embodiment of the present invention. Figure 7 is a top view showing a glass substrate with non-through holes according to one embodiment of the present invention. Figure 8 is a cross-sectional view taken along line B-B of the glass substrate in Figure 7. Figure 9 is a schematic cross-sectional view showing a non-through hole formed in a glass substrate according to one embodiment of the present invention. Figure 10 is a flow diagram showing a method for manufacturing a glass substrate according to one embodiment of the present invention. Figure 11 is a perspective view showing a laser irradiation process according to one embodiment of the present invention. Figure 12 is a schematic diagram for comparing a glass substrate before and after through hole formation according to one embodiment of the present invention.

[0025] Embodiments of the present invention will be described below with reference to the drawings.

[0026] [First Embodiment] First, the glass composition, properties, and manufacturing method of the glass substrate for semiconductor packaging (hereinafter referred to as "glass substrate") according to the first embodiment of the present invention will be described. The glass substrate according to this embodiment is used in the manufacture of a glass substrate having holes (through holes or non-through holes), and is a glass substrate in the state before holes are formed (non-porous glass substrate).

[0027] The glass substrate according to the first embodiment has a glass composition of SiO in mol%. ２ 65-85%, Al ２ O ３ 0-10%, B ２ O ３ 1-20%, Li ２ O 0-3%, Na ２ O 1-20%, K ２It is preferable that it contains 0-5% of O. The reasons for limiting the content of each component as described above are shown below. In the description of the content of each component, the percentages represent mole percent unless otherwise specified.

[0028] SiO ２ SiO is a component that forms the framework of glass. ２ If the content is too low, chemical resistance decreases. In particular, the HF etching rate increases, which increases the rate of hole diameter expansion when forming holes, and the taper angle of the holes becomes larger. In other words, it becomes difficult to form holes that are close to a straight shape. Therefore, SiO ２ The lower limit is preferably 65% ​​or more, more preferably 68% or more, more preferably 69% or more, more preferably 70% or more, more preferably 71% or more, more preferably 72% or more, more preferably 73% or more, more preferably 74% or more, more preferably 75% or more, more preferably 76% or more, more preferably 77% or more, more preferably 78% or more, more preferably 79% or more, and particularly preferably 80% or more. On the other hand, SiO ２ If the content is too high, the high-temperature viscosity increases, requiring more heat for melting, which raises the melting cost, and also increases the SiO content. ２ Undissolved raw materials may remain, potentially leading to a decrease in yield. Furthermore, cristobalite is more likely to precipitate during molding. Also, SiO ２ If the content of SiO is too high, the glass is more likely to split into phases. When the glass splits into phases, the glass substrate becomes cloudy, the transmittance of the glass substrate decreases, and the etching rate increases. When the transmittance of the glass substrate decreases, when a laser is irradiated onto the glass substrate, the laser light is scattered, making it difficult to form modified areas. Also, when the etching rate increases, it becomes difficult to form holes that are close to a straight shape. Therefore, SiO ２ The upper limit is preferably 85% or less, more preferably 84% or less, more preferably 83.5% or less, more preferably 83% or less, more preferably 82.5% or less, and particularly preferably 82% or less.

[0029] Al ２ O ３ Al is a component that forms the framework of glass.２ O ３ If the content is too low, chemical resistance will decrease. In particular, the HF etching rate will increase, which will increase the rate at which the hole diameter expands when forming holes, and the taper angle of the holes will increase. In other words, it will become difficult to form holes that are close to a straight shape. Also, Al ２ O ３ If the content is too low, the glass will easily split into phases. When the glass splits into phases, the glass substrate becomes cloudy, the transmittance of the glass substrate decreases, and the etching rate increases. When the transmittance of the glass substrate decreases, when a laser is irradiated onto the glass substrate, the laser light is scattered, making it difficult to form modified areas. Therefore, Al ２ O ３ The lower limit of is preferably 0% or more, more preferably 0.1% or more, more preferably 0.5% or more, more preferably 0.7% or more, more preferably 0.8% or more, more preferably 0.9% or more, more preferably 1% or more, more preferably 1.1% or more, more preferably 1.2% or more, more preferably 1.3% or more, more preferably 1.4% or more, more preferably 1.5% or more, more preferably 1.6% or more, more preferably 1.7% or more, more preferably 1.8% or more, more preferably 1.9% or more, more preferably 2% or more, more preferably 2.1% or more, more preferably 2.2% or more, more preferably 2.3% or more, more preferably 2.4% or more, more preferably 2.5% or more, more preferably 2.6% or more, more preferably 2.7% or more, more preferably 2.8% or more, and particularly preferably 3% or more. On the other hand, Al ２ O ３ If the content is too high, the high-temperature viscosity increases, and meltability and moldability tend to decrease. Also, it becomes difficult to form a suitable modified area with a laser. Therefore, Al ２ O ３ The upper limit of the amount is preferably 10% or less, more preferably 9% or less, more preferably 8% or less, more preferably 7.5% or less, more preferably 7% or less, more preferably 6.5% or less, more preferably 6% or less, more preferably 5.5% or less, and particularly preferably 5% or less.

[0030] B ２ O ３This component forms the framework of the glass and also reduces its high-temperature viscosity. ２ O ３ If the content is too low, the high-temperature viscosity will increase, and meltability and moldability will easily decrease. Therefore, B ２ O ３ The lower limit is preferably 0% or more, more preferably 1% or more, more preferably 2% or more, more preferably 3% or more, more preferably 4% or more, more preferably 5% or more, more preferably 6% or more, more preferably 7% or more, more preferably 8% or more, more preferably 9% or more, more preferably 10% or more, more preferably 11% or more, more preferably 11.5% or more, more preferably 11.6% or more, more preferably 11.7% or more, more preferably 11.8% or more, more preferably 11.9% or more, and particularly preferably 12% or more. On the other hand, B ２ O ３ If the content is too high, the chemical resistance decreases. In particular, the HF etching rate increases, so the taper angle when holes are formed becomes larger. Also, B ２ O ３ If the content is too high, the glass will easily undergo phase separation. When the glass undergoes phase separation, the glass substrate becomes cloudy, the transmittance of the glass substrate decreases, and the etching rate increases. When the transmittance of the glass substrate decreases, when the glass substrate is irradiated with a laser, the laser light scatters, making it difficult to form modified areas. Also, when the etching rate increases, it becomes difficult to form holes that are close to a straight shape. Therefore, B ２ O ３ The upper limit of the amount is preferably 20% or less, more preferably 18% or less, more preferably 17% or less, more preferably 16% or less, more preferably 15% or less, more preferably 14% or less, more preferably 13.5% or less, more preferably 13.4% or less, more preferably 13.3% or less, more preferably 13.2% or less, more preferably 13.1% or less, and particularly preferably 13% or less.

[0031] Li ２ O is an optional component that reduces the high-temperature viscosity of the glass and increases its meltability, and its content may be 0%. Li ２If the oxygen content is too low, the high-temperature viscosity will increase, and meltability and moldability will easily decrease. Therefore, Li ２ The lower limit of O is preferably 0% or more, more preferably 0.001% or more, more preferably 0.005% or more, and particularly preferably 0.01% or more. On the other hand, Li ２ If the O content is too high, batch costs will increase, and manufacturing costs will rise. Also, Li ２ If the oxygen content is too high, the glass becomes more prone to phase separation, which can reduce the transmittance of the glass substrate and increase the etching rate. When the transmittance of the glass substrate decreases, the laser light scatters when the glass substrate is irradiated with a laser, making it difficult to form modified areas. Also, when the etching rate increases, it becomes difficult to form holes that are close to a straight shape. Therefore, Li ２ The upper limit of O is preferably 3% or less, more preferably 2% or less, more preferably 1% or less, more preferably 0.5% or less, more preferably 0.3% or less, more preferably 0.2% or less, and particularly preferably 0.1% or less.

[0032] Na ２ O is a component that reduces the high-temperature viscosity of glass and increases its meltability. Na ２ If the O content is too low, the high-temperature viscosity will increase, and meltability and moldability will easily decrease. Therefore, Na ２ The lower limit of O is preferably 1% or more, more preferably 2% or more, more preferably 3% or more, more preferably 3.5% or more, and particularly preferably 4% or more. On the other hand, Na ２ If the O content is too high, the coefficient of thermal expansion will increase, leading to greater deformation of the glass substrate during semiconductor device mounting, and potentially causing the glass substrate to break. Also, Na ２ If the O content is too high, the glass becomes more prone to phase separation, leading to a decrease in the transmittance of the glass substrate and an increase in the etching rate. When the transmittance of the glass substrate decreases, the laser light is scattered when the glass substrate is irradiated with a laser, making it difficult to form modified areas. Also, when the etching rate increases, it becomes difficult to form holes that are close to a straight shape. Therefore, Na ２The upper limit of O is preferably 20% or less, more preferably 18% or less, more preferably 15% or less, more preferably 14% or less, more preferably 13% or less, more preferably 12% or less, more preferably 11% or less, more preferably 10% or less, more preferably 9% or less, more preferably 8% or less, more preferably 7% or less, more preferably 6% or less, more preferably 5.5% or less, more preferably 5.4% or less, more preferably 5.3% or less, more preferably 5.2% or less, more preferably 5.1% or less, and particularly preferably 5% or less.

[0033] K ２ O is an optional component that reduces the high-temperature viscosity of the glass and increases its meltability, and its content may be 0%. K ２ If the O content is too low, the high-temperature viscosity will increase, and meltability and moldability will easily decrease. Therefore, K ２ The lower limit of O is preferably 0% or more, more preferably 0.001% or more, more preferably 0.003% or more, more preferably 0.005% or more, more preferably 0.008% or more, and particularly preferably 0.01% or more. On the other hand, K ２ If the O content is too high, the coefficient of thermal expansion will increase, leading to greater deformation of the glass substrate during semiconductor device mounting, and potentially causing the glass substrate to break. Also, K ２ If the O content is too high, dielectric loss increases, and the device characteristics of the glass substrate tend to deteriorate. Therefore, K ２ The upper limit of O is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1% or less, more preferably 0.9% or less, more preferably 0.8% or less, more preferably 0.7% or less, more preferably 0.6% or less, and particularly preferably 0.5% or less.

[0034] MgO is an optional component that enhances HF resistance and also reduces the high-temperature viscosity of the glass, thereby improving meltability. Its content may be as low as 0%. If the MgO content is too low, the HF etching rate increases, and the taper angle of the holes tends to become larger. Also, if the MgO content is too low, the high-temperature viscosity increases, and meltability and moldability tend to decrease. Therefore, the lower limit of MgO is preferably 0% or more, more preferably 0.01% or more, more preferably 0.1% or more, more preferably 0.2% or more, more preferably 0.3% or more, more preferably 0.4% or more, and particularly preferably 0.5% or more. On the other hand, if the MgO content is too high, the glass tends to separate into phases, and the transmittance of the glass substrate decreases. As a result, when a laser is irradiated onto the glass substrate, the laser light is scattered, and it becomes difficult to form modified areas. Also, if the MgO content is too high, the mass of the residue generated when etching the glass substrate to form holes increases. This makes the etching apparatus more prone to residue clogging, increasing the frequency of residue removal and raising the manufacturing cost of the glass substrate. Furthermore, an increase in the mass of residue can cause residue to adhere to the inside of holes when etching the glass substrate to form holes, hindering the supply of etching solution to the inside of the holes. This can lead to a larger taper angle of the holes (i.e., difficulty in forming straight-shaped holes) or a larger variation in the diameter of the holes. Therefore, the upper limit of MgO is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1.5% or less, and particularly preferably 1% or less.

[0035] CaO is an optional component used to reduce the high-temperature viscosity of the glass and improve its meltability, and its content may be as low as 0%. If the CaO content is too low, the high-temperature viscosity will increase, and meltability and moldability will tend to decrease. Therefore, the lower limit of CaO is preferably 0% or more, more preferably 0.01% or more, more preferably 0.1% or more, more preferably 0.2% or more, more preferably 0.3% or more, more preferably 0.4% or more, and particularly preferably 0.5% or more. Also, if the CaO content is too high, the mass of residue generated when etching holes in the glass substrate will increase. This makes it easier for residue to clog the etching apparatus, increasing the frequency of residue removal and raising the manufacturing cost of the glass substrate. Furthermore, when the mass of residue increases, when etching holes in the glass substrate, the residue adheres to the inside of the holes, hindering the supply of etching solution to the inside of the holes. As a result, the taper angle of the holes may increase (i.e., it may become difficult to form straight-shaped holes), or the variation in hole diameter may increase. Therefore, the upper limit of CaO is preferably 8% or less, more preferably 7% or less, more preferably 6% or less, more preferably 5% or less, more preferably 4% or less, more preferably 3.8% or less, more preferably 3.5% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1.5% or less, and particularly preferably 1% or less.

[0036] SrO is an optional component used to reduce the high-temperature viscosity of the glass and improve its meltability, and its content may be as low as 0%. If the SrO content is too low, the high-temperature viscosity will increase, and meltability and moldability will tend to decrease. Therefore, the lower limit of SrO is preferably 0% or more, more preferably 0.01% or more, more preferably 0.1% or more, more preferably 0.2% or more, more preferably 0.3% or more, more preferably 0.4% or more, and particularly preferably 0.5% or more. On the other hand, if the SrO content is too high, the coefficient of thermal expansion will increase, leading to greater deformation of the glass substrate during semiconductor device mounting, and there is a risk of the glass substrate breaking. Also, if the SrO content is too high, the mass of residue generated when etching the glass substrate to form holes will increase. This makes it easier for residue to clog the etching equipment, increasing the frequency of residue removal and raising the manufacturing cost of the glass substrate. Furthermore, as the mass of the residue increases, when etching the glass substrate to form holes, the residue adheres to the inside of the holes, hindering the supply of etching solution to the inside of the holes. This can lead to an increase in the taper angle of the holes (i.e., difficulty in forming straight-shaped holes) or an increase in the variation in hole diameter. Therefore, the upper limit of SrO is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1.5% or less, and particularly preferably 1% or less.

[0037] BaO is an optional component that reduces the high-temperature viscosity of the glass and increases its meltability, and its content may be as low as 0%. It is also a component that enhances resistance to devitrification. If the BaO content is too low, it becomes difficult to enjoy the above effects. Therefore, the lower limit of the BaO content is preferably 0% or more, more preferably 0.01% or more, more preferably 0.1% or more, more preferably 0.2% or more, and particularly preferably 0.3% or more. On the other hand, if the BaO content is too high, the coefficient of thermal expansion increases, which can lead to greater deformation of the glass substrate during semiconductor device mounting and the risk of the glass substrate breaking. Also, if the BaO content is too high, the mass of residue generated when etching the glass substrate to form holes increases. This makes it easier for residue to clog the etching equipment, increasing the frequency of residue removal and raising the manufacturing cost of the glass substrate. Furthermore, if the mass of residue increases, when etching the glass substrate to form holes, the residue adheres to the inside of the holes, hindering the supply of etching solution to the inside of the holes. Therefore, the taper angle of the holes becomes larger (i.e., it becomes difficult to form straight-shaped holes), and the variation in hole diameter increases. Accordingly, the upper limit of BaO is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1.5% or less, more preferably 1% or less, more preferably 0.9% or less, more preferably 0.8% or less, more preferably 0.7% or less, more preferably 0.6% or less, and particularly preferably 0.5% or less.

[0038] If the total content of MgO, CaO, SrO, and BaO is too low, the high-temperature viscosity will increase, and meltability and moldability will tend to decrease. Therefore, the lower limit range for the total content of MgO, CaO, SrO, and BaO is preferably 0% or more, more preferably 0.01% or more, more preferably 0.1% or more, more preferably 0.2% or more, more preferably 0.3% or more, more preferably 0.4% or more, and particularly preferably 0.5% or more. On the other hand, if the total content of MgO, CaO, SrO, and BaO is too high, the coefficient of thermal expansion will increase, causing greater deformation of the glass substrate during semiconductor device mounting, and there is a risk of the glass substrate breaking. In addition, if the total content of MgO, CaO, SrO, and BaO is too high, the mass of residue generated when etching holes in the glass substrate will increase. This makes residue clogging more likely in the etching apparatus, increases the frequency of residue removal, and raises the manufacturing cost of the glass substrate. Furthermore, as the mass of the residue increases, when etching the glass substrate to form holes, the residue adheres to the inside of the holes, hindering the supply of etching solution to the inside of the holes. This can lead to an increase in the taper angle of the holes (i.e., difficulty in forming straight-shaped holes) or an increase in the variation in hole diameter. Therefore, the upper limit range for the total content of MgO, CaO, SrO, and BaO is preferably 8% or less, more preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, more preferably 1.5% or less, and particularly preferably 1% or less.

[0039] SnO ２ SnO is a component that has good clarifying properties in the high-temperature range, and is also an optional component that reduces high-temperature viscosity and improves meltability. Therefore, in order to produce glass substrates with good yield, SnO ２ It is preferable to include SnO ２ The content of may be 0%. Also, when forming wiring on the main surface of a glass substrate, if bubbles are exposed on the main surface, there is a risk of the wiring breaking. In particular, in recent years, wiring has become smaller and smaller, and even minute bubbles that are difficult to detect by image inspection machines, etc., may cause the wiring to break. For this reason, the glass substrate according to this embodiment is SnO ２It is preferable to increase the content, enhance the clarification effect, and reduce the amount of foam. Therefore, for SnO ２ The lower limit amount is preferably 0% or more, more preferably 0.01% or more, still more preferably 0.05% or more, and particularly preferably 0.08% or more. On the other hand, if the content of SnO ２ is too high, devitrification crystals of SnO ２ are likely to precipitate, which may cause a decrease in yield. Therefore, the upper limit amount of SnO ２ is preferably 1% or less, more preferably 0.8% or less, and particularly preferably 0.5% or less.

[0040] As described above, SnO ２ is suitable as a clarifying agent. As long as the glass properties are not impaired, as a clarifying agent, instead of SnO ２ or together with SnO ２ , F, SO ３ , C, or metal powders such as Al and Si can be added up to 1% each (preferably up to 0.8%, particularly preferably up to 0.5%). Also, as a clarifying agent, CeO ２ can also be added. However, if the content of CeO ２ is too high, the glass will be colored, and when laser irradiation is performed on the glass substrate to form a modified portion, the heat generation at the irradiated location of the laser will increase, and defects such as cracks are likely to occur. For this reason, the upper limit of the content of CeO ２ is preferably 0.1% or less, more preferably 0.05% or less, and particularly preferably 0.01% or less.

[0041] Cl is an optional component for promoting the initial melting of the glass batch. Also, if Cl is added, the action of the fining agent can be promoted. As a result of these, while reducing the melting cost, the long life of the glass manufacturing furnace can be achieved, but the Cl content may be 0%. Therefore, the lower limit of Cl is preferably 0% or more, more preferably 0.001% or more, more preferably 0.01% or more, more preferably 0.05% or more, more preferably 0.08% or more, and particularly preferably 0.1% or more. On the other hand, if the Cl content is too high, the strain point tends to decrease, and there is a risk of reducing the peel strength and deforming the glass substrate during the heat treatment step in the plating process. Therefore, the upper limit of Cl is preferably 3% or less, more preferably 2% or less, more preferably 1% or less, more preferably 0.8% or less, and particularly preferably 0.5% or less. As a raw material for introducing Cl, for example, raw materials such as NaCl can be used. Also, since Cl is a component that volatilizes during melting, the Cl content in the batch may be appropriately adjusted during production so that the Cl amount in the formed glass substrate satisfies the above range.

[0042] As a fining agent, As ２ O ３ and Sb ２ O ３ are also effective. However, As ２ O ３ and Sb ２ O ３ are components that increase the environmental load. Therefore, the glass substrate according to the present embodiment preferably does not substantially contain these components, and the content is preferably 0 to 0.05%.

[0043] The glass substrate according to the present embodiment preferably contains at least one of SnO ２ and Cl as a fining agent in order to promote the fining action and reduce the melting cost.

[0044] In addition to the above components, for example, as optional components, the following components may be added. The content of other components other than the above components is preferably 5% or less, more preferably 1% or less, from the viewpoint of accurately enjoying the effects of the present invention.

[0045] TiO ２ This is an optional component that lowers high-temperature viscosity and increases meltability, and its content may be 0%. Therefore, TiO ２ The lower limit of TiO is preferably 0% or more, more preferably 0.0001% or more, more preferably 0.0005% or more, and particularly preferably 0.0006% or more. ２ If a large amount of TiO is included, the glass substrate will become discolored, and when the glass substrate is irradiated with a laser to form a modified area, the heat generated at the laser irradiation area will increase, making it easier for defects such as cracks to occur. Therefore, TiO ２ The upper limit is preferably 0.01% or less, more preferably 0.009% or less, more preferably 0.008% or less, and particularly preferably 0.006% or less.

[0046] ZnO is an optional component used to lower high-temperature viscosity and improve meltability, and its content may be 0%. Therefore, the lower limit of ZnO is preferably 0% or more, more preferably 0.1% or more, more preferably 0.3% or more, and more preferably 0.6% or more. On the other hand, if a large amount of ZnO is included, the glass substrate will become discolored, and when the glass substrate is irradiated with a laser to form a modified area, the heat generated in the laser-irradiated area will increase, making it easier for defects such as cracks to occur. Therefore, the upper limit of ZnO is preferably 1% or less, more preferably 0.9% or less, more preferably 0.85% or less, and particularly preferably 0.8% or less.

[0047] P ２ O ５ This is an optional component that enhances HF resistance and facilitates the formation of holes in the glass substrate that are close to a straight shape, and its content may be 0%. Therefore, P ２ O ５ The lower limit of P is preferably 0% or more, more preferably 0.01% or more, and particularly preferably 0.05% or more. On the other hand, P ２ O ５ When a large amount of is included, the glass becomes more prone to phase separation. When the glass separates, the glass substrate becomes cloudy and the transmittance of the glass substrate decreases. As a result, when a laser is irradiated onto the glass substrate, the laser light is scattered, making it difficult to form a modified area. Therefore, P ２O ５ The upper limit of the amount is preferably 1% or less, more preferably 0.5% or less, more preferably 0.3% or less, and particularly preferably 0.2% or less.

[0048] CuO is a component that colors glass. If the CuO content is too high, the glass substrate will become colored, and when the glass substrate is irradiated with a laser to form holes, the heat generated at the laser irradiation site will increase, making it easier for defects such as cracks to occur. Therefore, it is desirable to have a low CuO content, and the upper limit is preferably 1% or less, more preferably 0.5% or less, and particularly preferably 0.2% or less. The lower limit of CuO may be, for example, 0.01% or more.

[0049] Y ２ O ３ Nb ２ O ５ La ２ O ３ These are components that enhance mechanical properties such as Young's modulus, but if the combined amount and individual content of these components are too high, raw material costs tend to increase. Therefore, Y ２ O ３ Nb ２ O ５ La ２ O ３ The upper limits of the combined amount and individual content are preferably 1% or less, more preferably 0.5% or less, more preferably 0.3% or less, and particularly preferably 0.1% or less. ２ O ３ Nb ２ O ５ La ２ O ３ The lower limit range for the combined amount and individual content may be, for example, 0.01% or more.

[0050] Fe ２ O ３ Fe is a component that is inevitably mixed in from the glass raw materials, and is also a component that colors the glass. ２ O ３ If the content is too low, raw material costs tend to rise. On the other hand, Fe ２ O ３If the content is too high, the glass substrate will become discolored, and when the glass substrate is irradiated with a laser to form holes, the heat generated at the laser irradiation site will be excessive, making it easier for defects such as cracks to occur. Therefore, Fe ２ O ３ The content is preferably 0 to 200 ppm, more preferably 1 to 150 ppm, and particularly preferably 30 to 100 ppm.

[0051] ZrO ２ ZrO is a component that inevitably gets mixed in from the refractory materials used in glass manufacturing furnaces. ２ If the content is too high, devitrified crystals are more likely to precipitate. On the other hand, ZrO ２ To reduce the content of ZrO, the melting temperature must be lowered, which makes it difficult to melt the glass. Therefore, ZrO ２ The upper limit of the amount is preferably 1% or less, more preferably 0.05% or less, more preferably 0.03% or less, and particularly preferably 0.01% or less.

[0052] The glass substrate according to this embodiment preferably has the following characteristics.

[0053] When the HF etching rate of the glass substrate before heat treatment is ER and the HF etching rate of the glass substrate after heat treatment is ERa, the value of ER / ERa is less than 1. In other words, ER < ERa. The value of ER / ERa is preferably 0.95 or less, more preferably 0.9 or less, more preferably 0.85 or less, more preferably 0.8 or less, more preferably 0.75 or less, more preferably 0.7 or less, more preferably 0.65 or less, more preferably 0.6 or less, more preferably 0.55 or less, and particularly preferably 0.5 or less. This makes it possible to lower the HF etching rate ER of the glass substrate before heat treatment, and to reduce the taper angle of the holes, that is, to form holes that are close to a straight shape. Also, the value of ER / ERa is 0.2 or more, preferably 0.25 or more, more preferably 0.3 or more, more preferably 0.35 or more, and particularly preferably 0.4 or more. This makes it difficult for the HF etching rate to increase even when the glass substrate is heat-treated, and it is possible to suppress the increase in the taper angle of the holes due to heat treatment.

[0054] (Method for measuring HF etching rate) Here, the HF etching rate ER before heat treatment refers to the value measured by the following procedures (1), (3) to (5), and the HF etching rate ERa after heat treatment refers to the value measured by the following procedures (1) to (5). In other words, when measuring the HF etching rate ER before heat treatment, the heat treatment procedure in (2) is omitted compared to when measuring the HF etching rate ERa after heat treatment. (1) Optically polish both sides of a glass substrate sample with a thickness of 1 mm and dimensions of 20 mm x 35 mm. (2) Heat treatment is performed from room temperature (25°C) according to the temperature profile shown in Figure 1. That is, the glass substrate sample is heated from 25°C to (Ta + 30°C) at a rate of 5°C / min, held at (Ta + 30°C) for 60 minutes, then cooled from (Ta + 30°C) to 300°C at a rate of 0.7°C / min, and then cooled from 300°C to 25°C at a rate of 10°C / min. Here, Ta represents the annealing point. (3) Mask a portion of the main surface of the glass substrate sample. (4) Immerse the glass substrate sample in the etching solution for 10 minutes to perform etching. Use 300 mL of a 2.5 mol / L HF aqueous solution as the etching solution. When etching, set the water bath stirrer to 30°C and stir at approximately 600 rpm. (5) Remove the mask, wash the glass substrate sample, and measure the step difference between the masked area and the eroded area using a surfcorder (ET4000A: manufactured by Kosaka Laboratory Co., Ltd.). Calculate the HF etching rate by dividing the step difference value by the immersion time.

[0055] To reduce the ER / ERa value, it is effective to suppress phase separation of the glass during molding by rapidly cooling the glass substrate when it is formed from molten glass. Methods for rapid cooling during molding include press molding and increasing the cooling rate during slow cooling in overflow molding, as described later.

[0056] The HF etching rate ER of the glass substrate before heat treatment is preferably 0.01 μm / min or more and 0.65 μm / min or less. The HF etching rate ER of the glass substrate before heat treatment is preferably 0.65 μm / min or less, more preferably 0.6 μm / min or less, more preferably 0.55 μm / min or less, more preferably 0.5 μm / min or less, more preferably 0.45 μm / min or less, more preferably 0.4 μm / min or less, more preferably 0.35 μm / min or less, more preferably 0.3 μm / min or less, more preferably 0.25 μm / min or less, and particularly preferably 0.2 μm / min or less. This allows the diffusion rate of the etching solution to be higher than the etching rate, which promotes the supply of the etching solution into the inside of the pores and makes it easier to reduce the taper angle. Furthermore, the ER is preferably 0.03 μm / min or more, more preferably 0.05 μm / min or more, more preferably 0.07 μm / min or more, more preferably 0.09 μm / min or more, more preferably 0.1 μm / min or more, more preferably 0.11 μm / min or more, more preferably 0.12 μm / min or more, more preferably 0.13 μm / min or more, more preferably 0.14 μm / min or more, and particularly preferably 0.15 μm / min or more. This makes it possible to shorten the time required for the etching process.

[0057] The HF etching rate ERa of the glass substrate after heat treatment is preferably 0.1 μm / min or more and 0.7 μm / min or less. The HF etching rate ERa of the glass substrate after heat treatment is preferably 0.65 μm / min or less, more preferably 0.6 μm / min or less, more preferably 0.55 μm / min or less, more preferably 0.5 μm / min or less, more preferably 0.45 μm / min or less, and particularly preferably 0.4 μm / min or less. This allows the diffusion rate of the etching solution to be increased compared to the etching rate, which promotes the supply of the etching solution to the inside of the pores and makes it easier to reduce the taper angle. Furthermore, ERa is preferably 0.15 μm / min or more, more preferably 0.2 μm / min or more, more preferably 0.25 μm / min or more, more preferably 0.3 μm / min or more, and particularly preferably 0.35 μm / min or more. This makes it possible to shorten the time required for the etching process.

[0058] The average thermal expansion coefficient CTE in the temperature range of 30 to 380°C is preferably 20 × 10⁻⁶. －７ / ℃ or higher, more preferably 25 × 10 －７ / ℃ or higher, more preferably 30 × 10 －７ / ℃ or higher, more preferably 32 × 10 －７ / ℃ or higher, more preferably 33 × 10 －７ / ℃ or higher, particularly preferably 34 × 10 －７ It is above / °C. Furthermore, the average coefficient of thermal expansion CTE in the temperature range of 30 to 380°C is preferably 80 × 10 －７ / ℃ or lower, more preferably 75 × 10 －７ / ℃ or lower, more preferably 70 × 10 －７ / ℃ or lower, more preferably 60 × 10 －７ / ℃ or lower, more preferably 50 × 10 －７ / ℃ or lower, more preferably 45 × 10 －７ / ℃ or lower, more preferably 40 × 10 －７ / ℃ or lower, more preferably 38 × 10 －７ / ℃ or lower, particularly preferably 36 × 10 －７ The temperature is below / °C. This makes it easier to match the thermal expansion coefficient of Si when mounting semiconductor elements, and reduces deformation of the glass substrate.

[0059] The Young's modulus is preferably 50 GPa or higher, more preferably 53 GPa or higher, more preferably 55 GPa or higher, more preferably 57 GPa or higher, and particularly preferably 60 GPa or higher. This suppresses the occurrence of defects caused by deformation of the glass substrate during the mounting of semiconductor elements. The Young's modulus may also be, for example, 70 GPa or lower.

[0060] The strain point is preferably 400°C or higher, more preferably 430°C or higher, more preferably 460°C or higher, more preferably 470°C or higher, more preferably 480°C or higher, and particularly preferably 490°C or higher. This allows for increased peel strength by raising the heat treatment temperature in the plating process for the glass substrate, and also suppresses deformation of the substrate during heat treatment.

[0061] The softening point is preferably 815°C or lower, more preferably 810°C or lower, and particularly preferably 805°C or lower. This allows for a lower process temperature during heat treatment to improve the plate quality and phase separation state of the glass substrate, thereby reducing manufacturing costs.

[0062] The liquidus temperature is preferably 1300°C or lower, more preferably less than 1200°C, more preferably 1150°C or lower, and particularly preferably 1100°C or lower. This makes it easier to prevent the formation of devitrified crystals during molding, which can reduce productivity. Furthermore, it makes molding easier using the overflow down-draw method, which improves the surface quality of the glass substrate and reduces the manufacturing cost of the glass substrate. The liquidus temperature is an indicator of devitrification resistance; the lower the liquidus temperature, the better the devitrification resistance.

[0063] The liquid-phase viscosity is preferably 10 ４．０ dPa·s or higher, more preferably 10 ４．２ dPa·s or higher, more preferably 10 ４．４ dPa·s or higher, more preferably 10 ４．６ dPa·s or higher, particularly preferably 10 ４．８ The viscosity is dPa·s or higher. This makes devitrification less likely to occur during molding and reduces the manufacturing cost of the glass substrate. Liquid-phase viscosity is an indicator of devitrification resistance and moldability; the higher the liquid-phase viscosity, the better the devitrification resistance and moldability.

[0064] High temperature viscosity 10 ２．５ The temperature at dPa·s is preferably 1700°C or lower, more preferably 1680°C or lower, more preferably 1650°C or lower, more preferably 1640°C or lower, and particularly preferably 1630°C or lower. This makes it easier to melt the glass batch and reduces the manufacturing cost of the glass substrate. Also, B from the molten glass ２ O ３ or Na ２ The amount of volatilization of oxygen is reduced, making it difficult for a foreign layer to form on the molten glass surface, thus improving the homogeneity of the glass. ２．５ The temperature in dPa·s corresponds to the melting temperature, and the lower this temperature, the better the meltability.

[0065] The thickness of the glass substrate in this embodiment is not particularly limited, but is preferably 0.03 mm or more, more preferably 0.05 mm or more, more preferably 0.1 mm or more, more preferably 0.2 mm or more, more preferably 0.3 mm or more, more preferably 0.35 mm or more, more preferably 0.4 mm or more, more preferably 0.45 mm or more, and particularly preferably 0.5 mm or more. This makes the glass substrate less prone to deformation, and can suppress damage to the glass substrate and semiconductor elements when mounting semiconductor elements. Furthermore, the thickness of the glass substrate is preferably 2 mm or less, more preferably 1.8 mm or less, more preferably 1.6 mm or less, more preferably 1.4 mm or less, more preferably 1.3 mm or less, more preferably 1.2 mm or less, more preferably 1.1 mm or less, more preferably 1 mm or less, more preferably 0.9 mm or less, more preferably 0.8 mm or less, and particularly preferably 0.7 mm or less. This makes it possible to reduce the diameter of the holes when holes are formed. By reducing the diameter of the holes, it is possible to increase the mounting density of semiconductor elements on the glass substrate or to form fine wiring. The thickness of the glass substrate can be adjusted by controlling the flow rate and drawing speed during molding. Furthermore, processes such as slimming may be performed to adjust the thickness of the glass substrate.

[0066] The difference between the maximum and minimum distances between the first and second main surfaces of the glass substrate (TTV = Total Thickness Variation) is preferably 20 μm or less, more preferably 15 μm or less, more preferably 10 μm or less, more preferably 8 μm or less, more preferably 5 μm or less, more preferably 3 μm or less, more preferably 2 μm or less, and particularly preferably 1 μm or less. This results in high surface accuracy and makes it easier to improve the accuracy of the processing. In particular, it is possible to improve wiring accuracy, making high-density wiring possible. TTV can be measured, for example, by the Bow / Warp measuring device SBW-331ML / d manufactured by Kobelco Research Institute.

[0067] The amount of warpage of the glass substrate is preferably 60 μm or less, more preferably 55 μm or less, more preferably 50 μm or less, more preferably 45 μm or less, and particularly preferably 40 μm or less. The lower limit of the amount of warpage is not particularly limited, but may be, for example, 1 μm or more, or 5 μm or more. This makes it easier to improve the accuracy of the processing. In particular, it is possible to improve the wiring accuracy, making high-density wiring possible. Here, "amount of warpage" refers to the sum of the absolute value of the maximum distance between the highest point and the least squares focal plane and the absolute value of the distance between the lowest point and the least squares focal plane, and can be measured, for example, by a Bow / Warp measuring device SBW-331ML / d manufactured by Kobelco Research Institute.

[0068] The relative permittivity of the glass substrate at 25°C and a frequency of 10 GHz is preferably 5 or less, more preferably 4.9 or less, more preferably 4.8 or less, more preferably 4.7 or less, more preferably 4.6 or less, and particularly preferably 4.5 or less. This reduces the transmission loss when an electrical signal is transmitted to the glass substrate when the glass substrate is used in a high-frequency device.

[0069] The dielectric loss tangent of the glass substrate at 25°C and a frequency of 10 GHz is preferably 0.01 or less, more preferably 0.009 or less, more preferably 0.008 or less, more preferably 0.007 or less, more preferably 0.006 or less, more preferably 0.005 or less, more preferably 0.004 or less, and particularly preferably 0.003 or less. This reduces the transmission loss when an electrical signal is transmitted to the glass substrate when the glass substrate is used in a high-frequency device.

[0070] The linear transmittance of the glass substrate with a thickness of 0.5 mm according to this embodiment at wavelengths of 400 nm to 1100 nm is preferably 80% or more, more preferably 85% or more, and particularly preferably 90% or more. If the influence of coloring components in the glass is small and the absorption coefficient is small in this wavelength range, the heat generated at the laser irradiation site when laser light is irradiated to form a modified portion on the glass substrate will be small, and defects such as cracks will be less likely to occur. Alternatively, if there is little phase separation in the glass and the scattering coefficient is small in this wavelength range, the scattering of laser light can be suppressed, and the formation of a modified portion on the glass substrate is promoted.

[0071] Next, a method for manufacturing a glass substrate according to this embodiment will be described. As shown in Figure 2, the method for manufacturing a glass substrate according to this embodiment comprises a molding step S1 for molding a glass substrate from molten glass, and a cooling step S2 for cooling the molded glass substrate. In the cooling step S2, it is preferable to rapidly cool the glass substrate. More specifically, it is preferable to rapidly cool it so that the average cooling rate in the temperature range of (strain point -10°C) to (annealing point +200°C) is 1°C / second or more. The average cooling rate in the temperature range of (strain point -10°C) to (annealing point +200°C) is more preferably 3°C / second or more, more preferably 5°C / second or more, more preferably 7°C / second or more, more preferably 8°C / second or more, more preferably 10°C / second or more, more preferably 15°C / second or more, and particularly preferably 20°C / second or more. Note that an average cooling rate of "1°C / second or more" means that the average cooling rate is 1°C / second or faster than 1°C / second. By rapidly cooling at this average cooling rate, the glass substrate can be formed while suppressing the phase separation of the glass. If the phase separation of the glass substrate is progressing, the HF etching rate will increase. When the HF etching rate increases, the rate at which glass is removed by etching becomes faster than the rate at which residue generated inside the hole is discharged, so the amount of residue adhering to the inside of the hole increases. As a result, the circulation of the etching solution inside and outside the hole is hindered, the removal rate in the center of the glass substrate in the thickness direction decreases, and the taper angle of the inner wall of the hole increases. In this embodiment, by suppressing the phase separation of the glass, the HF etching rate can be reduced and a hole that is close to a straight shape can be formed.

[0072] For example, molding methods such as overflow downdraw, slot downdraw, rollout, and press molding can be used.

[0073] In the overflow downdraw method, a heat-resistant structure is used, which has a groove at its top, two sides extending along the groove and located on both sides of the groove, and a lower end where the lower parts of these two sides intersect. Molten glass is supplied to the groove at the top of such a heat-resistant structure and allowed to overflow from both sides. The overflowed molten glass is then allowed to flow down both sides of the heat-resistant structure and then merge at the lower end of the heat-resistant structure. The resulting glass ribbon is then pulled downwards to stretch it, a glass plate is cut from the glass ribbon, and then processed with cutting, edge finishing, cleaning, inspection, and packaging to manufacture a glass substrate. In the overflow downdraw method, the surface that will become the surface of the glass substrate does not come into contact with the heat-resistant structure and is formed in a free surface state, resulting in a forged surface. Therefore, it is possible to manufacture glass substrates with good surface quality without polishing at low cost, and thinning is also easy. Glass substrates formed by the overflow downdraw method have a mating surface in the middle of the thickness direction.

[0074] The glass substrate according to this embodiment is used in semiconductor packages, specifically in package substrates used for mounting semiconductor elements. Preferably, the glass substrate according to this embodiment is used to manufacture a perforated glass substrate. The perforated glass substrate manufactured using the glass substrate according to the present invention is particularly preferred for use as an interposer or core substrate in semiconductor package substrates. The glass substrate according to this embodiment is suitable for forming holes that are close to straight in shape, offers excellent productivity, and is less prone to deformation during semiconductor mounting, making it suitable for applications such as interposers and core substrates.

[0075] [Second Embodiment] Next, a perforated glass substrate for semiconductor packaging (hereinafter referred to as "perforated glass substrate") according to the second embodiment of the present invention will be described. The perforated glass substrate according to this embodiment has through holes and is manufactured by forming through holes in the glass substrate (non-perforated glass substrate) according to the first embodiment. Therefore, the perforated glass substrate according to the second embodiment has the same glass composition and properties as the glass substrate according to the first embodiment.

[0076] Figure 3 is a top view showing a perforated glass substrate G1 according to this embodiment, and Figure 4 is a cross-sectional view of the perforated glass substrate of Figure 3 taken along line A-A. As shown in Figures 3 and 4, the perforated glass substrate G1 according to this embodiment comprises a first main surface G1a, a second main surface G1b which is the opposite surface of the first main surface G1a, and a through hole 1 that penetrates between the first main surface G1a and the second main surface G1b. A first example of the through hole 1 is a constricted portion 1b in the center of the perforated glass substrate G1 in the thickness direction Z, with a diameter smaller than the diameter of the through hole 1 on the first main surface G1a and the second main surface G1b. In other words, the side surface 1a of the through hole 1 is inclined with respect to the thickness direction Z.

[0077] Figure 5 is a schematic cross-sectional view showing a first example of a through-hole 1 formed in a perforated glass substrate G1 according to this embodiment. The diameter D1 of the through-hole 1 on the first main surface G1a and the diameter D2 of the through-hole 1 on the second main surface G1b can be measured, for example, by observing the surface of the perforated glass substrate G1 with a transmission optical microscope and measuring the length from the image. The diameter D3 of the constricted portion 1b of the through-hole 1, the distance t1 between the first main surface G1a and the constricted portion 1b, and the distance t2 between the second main surface G1b and the constricted portion 1b can be measured by scribing the perforated glass substrate G1 so that the inner surface of the through-hole 1 is not exposed, observing the inside of the through-hole 1 with a transmission optical microscope from a direction perpendicular to the cross-section with the focus on the inside of the through-hole 1, and measuring the length from the image. As a transmission optical microscope, for example, a Nikon ECLIPSE LV100ND can be used.

[0078] The diameters D1 and D2 of the through-holes 1 are preferably 200 μm or less, more preferably 180 μm or less, more preferably 160 μm or less, more preferably 150 μm or less, more preferably 130 μm or less, more preferably 100 μm or less, more preferably 90 μm or less, more preferably 80 μm or less, more preferably 70 μm or less, more preferably 60 μm or less, and particularly preferably 50 μm or less. This allows for the formation of high-density through-holes 1, and when the glass substrate G1 is used in the manufacture of core substrates or interposers, the wiring density can be increased. Furthermore, the diameters D1 and D2 of the through-holes 1 are preferably 5 μm or more, more preferably 10 μm or more, more preferably 15 μm or more, more preferably 20 μm or more, more preferably 25 μm or more, and particularly preferably 30 μm or more. This makes it difficult for voids to form in the conductive material when a conductive part is formed inside the through-holes 1 by plating, and suppresses the problem of non-conductivity between the first main surface G1a and the second main surface G1b.

[0079] The ratio of the diameter D3 of the constricted portion 1b to the diameters D1 and D2 of the through-hole 1 in the first main surface G1a and the second main surface G1b (D3 / D1, D3 / D2) is preferably 99% or less, more preferably 95% or less, more preferably 90% or less, more preferably 85% or less, and particularly preferably 80% or less. This makes it easier to form a seed layer inside the hole by sputtering when forming a conductive portion inside the through-hole 1 by plating, and makes it easier to ensure adhesion of the plating. Also, the ratio (D3 / D1, D3 / D2) is preferably 5% or more, more preferably 10% or more, more preferably 15% or more, more preferably 20% or more, more preferably 25% or more, more preferably 30% or more, more preferably 35% or more, more preferably 40% or more, more preferably 45% or more, and particularly preferably 50% or more. This makes it easier to fill the conductive material when forming a conductive portion inside the through-hole 1 by plating, and can suppress the problem of no conductivity between the first main surface G1a and the second main surface G1b.

[0080] The average taper angle θ1 of the through hole 1 in the first example can be evaluated as follows. First, the taper angle θ1a of the side surface on the first main surface G1a side of the through hole 1, and the taper angle θ1b of the side surface on the second main surface G1b side of the through hole 1 are calculated using the following equations 1 and 2. θ1a = arctan((D1 - D3) / (2 × t1)) Equation 1 θ1b = arctan((D2 - D3) / (2 × t2)) Equation 2

[0081] Next, the average taper angle θ1 of the through hole 1 is calculated using the following equation 3: θ1 = (θ1a + θ1b) / 2 Equation 3

[0082] The average taper angle θ1 of the through-hole 1 is preferably 4° or less, more preferably 3.8° or less, more preferably 3.5° or less, more preferably 3.3° or less, more preferably 3° or less, more preferably 2.8° or less, more preferably 2.5° or less, and particularly preferably 2.3° or less. This allows for the formation of high-density through-holes 1, and when the glass substrate G1 is used in the manufacture of core substrates or interposers, the wiring density can be increased. Furthermore, the average taper angle θ1 is preferably greater than 0°, more preferably 0.2° or more, more preferably 0.4° or more, more preferably 0.6° or more, more preferably 0.8° or more, more preferably 1° or more, more preferably 1.2° or more, more preferably 1.4° or more, and particularly preferably 1.6° or more. This makes it easier to fill the conductive material when forming a conductive part inside the through-hole 1 by plating, and suppresses the problem of non-conductivity between the first main surface G1a and the second main surface G1b.

[0083] Figure 6 is a schematic cross-sectional view showing a second example of a through-hole 1 formed in a perforated glass substrate G1 according to one embodiment of the present invention. As shown in Figure 6, the through-hole 1 of the second example does not have a constricted portion in the center of the thickness direction Z of the perforated glass substrate G1. Furthermore, in the through-hole 1 of the second example, the diameter D1 of the through-hole 1 on the first main surface G1a is different from the diameter D2 of the through-hole 1 on the second main surface G1b, and the side surface 1a of the through-hole 1 is inclined with respect to the thickness direction Z.

[0084] The taper angle θ3 of the through hole in the second example, which does not have a constricted section, is calculated by the following equation 4: θ3 = arctan((D1 - D2) / (2 × t)) Equation 4

[0085] In the second example, the diameters D1 and D2 and the taper angle θ3 of the through hole 1 are preferably within the same numerical range as the diameters D1 and D2 and the mean taper angle θ1 of the through hole 1 in the first example.

[0086] [Third Embodiment] Next, a glass substrate for semiconductor packaging (hereinafter referred to as "perforated glass substrate") according to the third embodiment of the present invention will be described with reference to Figures 7 to 9. The perforated glass substrate according to this embodiment is a perforated glass substrate having non-through holes, and is manufactured by forming non-through holes in the glass substrate (non-perforated glass substrate) according to the first embodiment. Therefore, the perforated glass substrate according to the third embodiment has the same glass composition and properties as the glass substrate according to the first embodiment.

[0087] Figure 7 is a top view showing a perforated glass substrate G2 according to this embodiment, and Figure 8 is a cross-sectional view of the perforated glass substrate G2 of Figure 7 taken along line B-B. As shown in Figures 7 and 8, the glass substrate G2 according to this embodiment comprises a first main surface G2a, a second main surface G2b which is the opposite surface of the first main surface G2a, and non-through holes 2 provided on the first main surface G2a and the second main surface G2b. The diameter of the non-through holes 2 decreases as they move inward in the thickness direction from the first main surface G2a and the second main surface G2b towards the interior of the perforated glass substrate G2, and the bottom portion 2b of the non-through hole is provided at the point where the diameter is smallest. In other words, the side surface 2a of the non-through hole 2 is inclined with respect to the thickness direction Z. In this embodiment, non-through holes 2 are formed on both the first main surface G2a and the second main surface G2b, but non-through holes 2 may be formed on either the first main surface G2a or the second main surface G2b.

[0088] Figure 9 is a schematic cross-sectional view showing a non-through hole 2 formed in a perforated glass substrate G2 according to this embodiment. The diameter D4 of the non-through hole 2 on the first main surface G2a and the diameter D5 of the non-through hole 2 on the second main surface G2b can be measured in the same way as the diameters D1 and D2 of the through hole 1 in the second embodiment. The distance t3 between the first main surface G2a and the bottom 2b of the non-through hole, and the distance t4 between the second main surface G2b and the bottom 2b of the non-through hole can be measured in the same way as the distances t1 and t2 in the second embodiment.

[0089] The average taper angle θ2 of the non-through hole 2 can be evaluated as follows. First, the taper angle θ2a of the side surface on the first main surface G2a side of the non-through hole 2, and the taper angle θ2b of the side surface on the second main surface G2b side of the non-through hole 2 are calculated using the following equations 5 and 6. θ2a = arctan(D4 / (2×t3)) Equation 5 θ2b = arctan(D5 / (2×t4)) Equation 6

[0090] Next, the average taper angle θ2 of the non-through hole 2 is calculated using the following equation 7: θ2 = (θ2a + θ2b) / 2 Equation 7

[0091] [Fourth Embodiment] Next, a method for manufacturing a perforated glass substrate for semiconductor packaging according to the fourth embodiment of the present invention will be described with reference to Figures 10 to 10. As shown in Figure 10, the method for manufacturing a perforated glass substrate according to this embodiment comprises a preparation step S11 for preparing a glass substrate G0, a laser irradiation step S12 for irradiating the areas of the glass substrate G0 where holes (through holes or non-through holes) are to be formed with laser light to form modified areas, and an etching step S13 for etching the glass substrate G0 having modified areas to form perforated glass substrates G1 and G2 having holes.

[0092] In preparation step S11, a glass substrate G0 according to the first embodiment of the present invention is prepared. The glass substrate G0 may be prepared, for example, by cutting a glass plate formed by the overflow down-draw method to a predetermined size. Alternatively, a glass plate formed by other methods such as the slot down-draw method, roll-out method, or press molding may be cut to a predetermined size. When forming the glass plate, rapid cooling is preferable, as described above.

[0093] In the laser irradiation process S12, as shown in Figure 11, the glass substrate G0 is placed flat with the second main surface G0b facing downwards. The glass substrate G0 may be placed on a surface plate, for example (not shown). The irradiation unit of the laser irradiation device 3 is positioned away from the first main surface G0a so as to face the first main surface G0a of the glass substrate G0. The irradiation unit of the laser irradiation device 3 is configured to be movable in three dimensions by a drive device (not shown).

[0094] Next, the laser irradiation device 3 irradiates the first main surface G0a of the glass substrate G0 with laser light 3a perpendicular to it. It is preferable that the laser irradiation device 3 irradiates with a pulsed laser. With a pulsed laser, the glass substrate G0 can be heated efficiently by increasing the energy per pulse, and the glass substrate G0 can be prevented from being damaged by heat diffusion by shortening the pulse duration. It is preferable that the laser light 3a is a picosecond laser or a femtosecond laser, and the pulse width is preferably, for example, 50 fs or more and 100 ps or less. It is also preferable that the energy per pulse of the laser light 3a is, for example, 10 μJ or more and 300 μJ or less.

[0095] It is preferable to use a wavelength of laser light 3a between 400 nm and 1100 nm. For example, the wavelength of laser light 3a is 515 nm or 1030 nm.

[0096] The laser irradiation device 3 preferably shapes the laser beam 3a into a Gaussian beam shape or a Bessel beam shape using an optical system (not shown) including, for example, an axicon lens, and more preferably a Bessel beam shape. By shaping the laser beam 3a into a Bessel beam shape, a single laser pulse can form a modified portion Gm over the entire thickness direction of the glass plate G0, thereby shortening the time required to form the modified portion Gm. In this embodiment, the focal length of the laser beam 3a is, for example, 0.1 mm or more and 10 mm or less. The spot diameter of the laser beam 3a is, for example, 0.1 μm or more and 10 μm or less.

[0097] When the laser irradiation device 3 irradiates the glass substrate G0 with laser light 3a toward the first main surface G0a, modified portions Gm are formed on the glass substrate G0. By repeatedly moving the irradiation position of the laser light 3a relative to the glass substrate G0 and irradiating with the laser light 3a, multiple modified portions Gm are formed on the glass substrate G0. In this embodiment, each time the laser irradiation device 3 irradiates with one pulse of laser light 3a, the irradiation position of the laser light 3a relative to the glass substrate G0 is moved. In other words, each of the multiple modified portions Gm is formed by a single pulse of laser light 3a.

[0098] In etching step S13, the glass substrate G0, on which the modified portion Gm was formed in the laser irradiation step S12, is immersed in an etching solution to remove the modified portion Gm and form holes (through-holes 1 or non-through-holes 2). The type of etching solution is not particularly limited as long as the etching rate of the modified portion Gm is higher than the etching rate of the unmodified portion. For example, an aqueous HF solution (HF-based etching solution), an aqueous NaOH solution, or an aqueous KOH solution (alkaline etching solution) can be used. Note that HF-based etching solutions have a higher etching rate than alkaline etching solutions. Therefore, from the viewpoint of shortening the time required to form holes in the glass substrate, it is preferable to use an HF-based etching solution. When using an HF-based etching solution, HCl and H are added to the aqueous HF solution. ２ SO ４ HNO ３ One or more acids may be added to the etching solution to form a mixed aqueous solution. A surfactant may also be added to the etching solution. In etching step S13, after the modified portion Gm is removed to form through-holes 1 or non-through-holes 2, the non-modified portion around the modified portion Gm may be removed by etching to widen the diameter of through-holes 1 or non-through-holes 2 until the diameter of through-holes 1 or non-through-holes 2 reaches a desired value.

[0099] The temperature of the etching solution is not particularly limited, but it is preferable to lower the temperature of the etching solution in order to reduce the average taper angles θ1 and θ2. When using an etching solution containing HF, the upper limit of the etching solution temperature is preferably 30°C or lower, more preferably 20°C or lower, more preferably 10°C or lower, and particularly preferably 5°C or lower. Lowering the temperature of the etching solution lowers the etching rate, which reduces the amount of residue generated in the etching process S13, and makes it easier to scrape out the residue from inside the hole. As a result, etching of the hole tip is less likely to be hindered by residue during the formation of the through hole 1 or non-through hole 2, and the average taper angles θ1 and θ2 tend to become smaller. Also, when using an etching solution containing HF, the temperature of the etching solution may be above 0°C. When using an alkaline etching solution such as an aqueous NaOH solution or an aqueous KOH solution, the temperature of the etching solution is preferably 80°C or higher, more preferably 90°C or higher, more preferably 100°C or higher, and particularly preferably 110°C or higher. This allows for a higher etching rate and shortens the time required for the etching process S13. Furthermore, when using alkaline etching solutions such as NaOH aqueous solution or KOH aqueous solution, the temperature of the etching solution is preferably 130°C or lower, and particularly preferably 120°C or lower. This allows for a lower etching rate and reduces the average taper angles θ1 and θ2.

[0100] The concentration of the etching solution is not particularly limited and may be changed as appropriate to obtain the desired shape of the through-hole 1 or non-through-hole 2. For example, the concentration of the etching solution may be changed during the formation of the through-hole 1 or non-through-hole 2. During the etching process S13, the concentration of the etching solution changes, so it is preferable to circulate or replace the etching solution to maintain a constant concentration.

[0101] In etching step S13, it is preferable to stir the etching solution or apply ultrasonic waves to the etching solution. Alternatively, the glass substrate G0 may be agitated in the etching solution. This makes it easier to scrape out residue from inside the holes, and the average taper angles θ1 and θ2 tend to decrease.

[0102] Figure 12 is a schematic diagram for comparing the glass substrate G0 before etching process S13 and the perforated glass substrate G1 after etching process S13. As shown in Figure 12, in etching process S13, at least one of the first main surface G0a and the second main surface G0b is removed by etching, so the thickness t of the perforated glass substrate G1 after the through-hole 1 is formed is smaller than the thickness t0 of the glass substrate G0 before the through-hole is formed. In Figure 12, the perforated glass substrate G1 after the through-hole is formed is shown by a solid line, and the glass substrate G0 before the through-hole is formed is shown by a dashed line. Similarly, when forming a perforated glass plate G2 with non-through-holes, the plate thickness is also reduced.

[0103] Furthermore, in the perforated glass substrates G1 and G2 according to this embodiment, through holes 1 or non-through holes 2 are formed by the etching process S13. Therefore, at least the side surface 1a of the through hole 1 (inside the through hole 1), the side surface 2a of the non-through hole (inside the non-through hole 2), and one of the main surfaces are etched surfaces. As a result, the inside of the through hole 1, the inside of the non-through hole 2, and one of the main surfaces have excellent surface properties, are free from fine cracks, and have high strength. Therefore, by using the perforated glass substrates G1 and G2 according to this embodiment as core substrates or interposers, a package substrate that is resistant to damage can be obtained. On the other hand, if through holes 1 or non-through holes 2 are formed in the glass substrate G0 by methods such as laser ablation, the surface properties inside the through hole 1 or non-through hole 2 are poor, fine cracks are more likely to occur, and the strength is reduced.

[0104] In etching step S13, if etching is performed from both the first main surface G0a and the second main surface G0b of the glass substrate G0, the through hole 1 of the first example described above, that is, the through hole 1 having a constricted portion 1b, is formed. On the other hand, if etching step S13 is performed with a protective film attached to either the first main surface G0a or the second main surface G0b, etching is performed only from the main surface without the protective film, and the through hole 1 of the second example described above, that is, the through hole 1 without a constricted portion 1b, is formed.

[0105] Furthermore, the present invention is not limited to the configuration of the above embodiments, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the spirit of the invention.

[0106] In the above embodiment, multiple modified portions Gm are formed in the glass substrate G0, and one non-through hole 2 is formed for each modified portion Gm, but the embodiment is not limited to this. Multiple modified portions Gm may be formed and fused together by etching to form a non-through hole with a large opening area relative to the depth dimension of the hole. Such a non-through hole is called a cavity, and when mounting semiconductor elements or the like on a glass substrate, semiconductor elements or the like can be housed in the cavity.

[0107] The present invention will be described below based on examples. Note that the following examples are merely illustrative. The present invention is not limited in any way to the following examples.

[0108] Table 1 shows the glass composition and glass properties of Example 1 (Sample No. 1) and Comparative Example 1 (Sample No. 2) of the present invention. Table 2 shows the glass composition and glass properties of Examples 2 to 9 (Sample Nos. 3 to 10) of the present invention. Table 3 shows Examples 10 to 14 (Sample Nos. 11 to 15), Comparative Examples 2 and 3 (Sample Nos. 16 and 17) of the present invention.

[0109] First, glass batches prepared with glass raw materials to match the glass composition shown in the table were placed in a platinum crucible and melted at 1600-1650°C for 8 hours. During the melting of the glass batches, a platinum stirrer was used to stir and homogenize them. Next, for glasses No. 1 and 3-15, the molten glass was rapidly cooled by press molding to form a circular shape. The average cooling rate in the temperature range from (strain point Ps -10°C) to (annealing point Ta +200°C) was approximately 15°C / second. For glasses No. 2, 16, and 17, the molten glass was poured onto a carbon plate, formed into a plate shape, and then slowly cooled at a temperature near the annealing point for 30 minutes. For each glass substrate sample obtained in this way, the density, average thermal expansion coefficient CTE in the temperature range of 30-380°C, Young's modulus, strain point Ps, annealing point Ta, softening point Ts, and high-temperature viscosity 10 were measured. ４．０Temperature and high-temperature viscosity at dPa·s 10 ３．０ Temperature and high-temperature viscosity at dPa·s 10 ２．５ The temperature in dPa·s was evaluated.

[0110]

[0111]

[0112]

[0113] The density was measured using the well-known Archimedes method.

[0114] The average thermal expansion coefficient CTE in the temperature range of 30 to 380°C is the value measured using a dilatometer.

[0115] Young's modulus is a value measured using a well-known resonance method.

[0116] The strain point Ps, annealing point Ta, and softening point Ts were measured according to the ASTM C336 and C338 methods.

[0117] High temperature viscosity 10 ４．０ dPa·s, 10 ３．０ dPa·s, 10 ２．５ The temperature in dPa·s was measured using the platinum ball pulling method.

[0118] Next, the HF etching rate (ER) of the glass substrate samples before heat treatment for Examples 1 to 14 (samples No. 1, and 3 to 16) and Comparative Examples 1 to 3 (samples No. 2, 16, and 17) was measured according to the procedures (1), (3) to (5) of the above-mentioned (Method for Measuring HF Etching Rate). Furthermore, the HF etching rate (ERa) of the glass substrate samples after heat treatment for Examples 1 to 14 (samples No. 1, and 3 to 15) and Comparative Examples 1 to 3 (samples No. 2, 16, and 17) was measured according to the procedures (1) to (5) of the above-mentioned (Method for Measuring HF Etching Rate). The HF etching rate ER before heat treatment, the HF etching rate ERa after heat treatment, and the ratio ER / ERa of the HF etching rate ER before heat treatment to the HF etching rate ERa after heat treatment are shown in Tables 4 to 6.

[0119]

[0120]

[0121]

[0122] In the glass substrate samples of Examples 1 to 14 (Samples No. 1 and 3 to 15), the ER / ERa ratio was 0.44 to 0.98, which was within the range of 0.2 or more and less than 1. On the other hand, in the glass substrate samples of Comparative Examples 1 to 3 (Samples No. 2, 16, and 17), the ER / ERa ratio was 1.06 to 1.12, which was 1 or more.

[0123] Next, non-through holes were formed in the glass substrate samples of Example 1 (Sample No. 1) and Comparative Example 1 (Sample No. 2) using the following method. A picosecond pulsed laser, shaped into a vessel beam, was irradiated onto the glass substrate sample, which had been cut into a rectangular shape of 40 mm x 20 mm, from the first main surface side with an irradiation position spacing of approximately 200 μm, thereby forming approximately 8,000 modified areas on the glass substrate.

[0124] Next, glass substrate samples No. 1-2 and 1-3 were prepared by performing a preliminary heat treatment on the glass substrate sample No. 1. Specifically, glass substrate samples No. 1-2 were prepared by raising the temperature of glass substrate sample No. 1 from 25°C to 600°C (i.e., Ta+50°C) at a rate of 5°C / min, holding it at 600°C for 240 minutes, then cooling it from 600°C to 300°C at a rate of 0.7°C / min, and then cooling it from 300°C to 25°C at a rate of 10°C / min. Glass substrate samples No. 1-3 were prepared by... The glass substrate sample 1 was prepared by raising the temperature from 25°C to 580°C (i.e., Ta+30°C) at a rate of 5°C / min, holding it at 580°C for 30 minutes, then lowering the temperature from 580°C to 300°C at a rate of 0.7°C / min, and finally lowering the temperature from 300°C to 25°C at a rate of 10°C / min.

[0125] Then, following the procedures (1), (3) to (5) of the aforementioned (Method for Measuring HF Etching Rate), the HF etching rate (ER) of glass substrate samples No. 1-2 and 1-3 before heat treatment was measured. In addition, following the procedures (1) to (5) of the aforementioned (Method for Measuring HF Etching Rate), the HF etching rate (ERa) of glass substrate samples No. 1-2 and 1-3 after heat treatment was measured. Table 7 shows the HF etching rate ER before heat treatment, the HF etching rate ERa after heat treatment, and the ratio ER / ERa between the HF etching rate ER before heat treatment and the HF etching rate ERa after heat treatment. For comparison, Table 7 also shows the ER, ERa, and ratio ER / ERa of glass substrate sample No. 1.

[0126]

[0127] The specific ER / ERa ratios of the heat-treated glass substrate samples No. 1-2 and 1-3 were greater than those of the untreated glass substrate sample No. 1, and were closer to 1. Furthermore, comparing samples No. 1-2 and No. 1-3, sample No. 1-2, which underwent a higher heat treatment temperature and longer heat treatment time, had a higher specific ER / ERa ratio, closer to 1, than sample No. 1-2. The glass substrate samples No. 1-2 and 1-3, which underwent the aforementioned preliminary heat treatment, showed more advanced phase separation compared to sample No. 1, which did not undergo preliminary heat treatment. Additionally, the glass substrate sample No. 1-2, which underwent a higher preliminary heat treatment temperature and longer heat treatment time, showed more advanced phase separation than the glass substrate sample No. 1-3. From the above, it can be seen that the more advanced the phase separation in the glass substrate sample, the larger the ER / ERa value becomes and the closer it approaches 1.

[0128] Next, the glass substrate sample was etched under the following conditions. The glass substrate sample was placed in a polypropylene test tube containing the etching solution, and etching was performed by applying ultrasound to the etching solution. At this time, a PTFE jig was used to fix the glass substrate sample at a distance of 10 mm from the bottom of the test tube. An aqueous solution containing 2.5 mol / L of HF and 1.0 mol / L of HCl was used as the etching solution. The temperature of the etching solution was set to 10°C. To prevent the temperature from rising during ultrasound application, a chiller was used to circulate the water in the ultrasonic device and maintain the water temperature at 10°C. An ultrasonic cleaner (VS-100III: manufactured by AS ONE Corporation) was used to apply ultrasonic vibrations, and 28 kHz ultrasound was applied to the etching solution.

[0129] Non-through holes were formed in the glass substrate samples obtained by this method. The average taper angle θ2 of these non-through holes was determined by the method described above.

[0130] Tables 8 and 9 show the etching time, the thickness of the glass substrate sample before etching, the thickness of the glass substrate sample after etching, and the shape of the non-through holes.

[0131] In the table, "Presence or Absence of Heat Treatment" indicates whether the heat treatment described in (2) of the aforementioned (Method for Measuring HF Etching Rate) was performed before forming the modified area, and whether the holes were formed without performing the heat treatment described in (2).

[0132]

[0133]

[0134] Table 8 shows that the glass substrate samples before heat treatment (experimental conditions 1-3) manufactured using glass substrate sample No. 1 of the example have a smaller average taper angle θ2 for non-through holes and form non-through holes that are closer to a straight shape than the glass substrate samples before heat treatment (experimental conditions 4-6). Furthermore, as mentioned above, Table 4 shows that the HF etching rate ER of the glass substrate sample before heat treatment manufactured using glass substrate sample No. 1 of the example is smaller than the HF etching rate ERa of the glass substrate sample after heat treatment. In other words, glass substrate samples with a small HF etching rate have a smaller average taper angle θ2 for non-through holes and form non-through holes that are closer to a straight shape than glass substrate samples with a large HF etching rate.

[0135] Table 9 shows the average taper angle θ2 of the glass substrate samples before heat treatment (experimental conditions 7-9) manufactured using comparative example glass substrate sample No. 2. The average taper angle θ2 of the glass substrate samples after heat treatment (experimental conditions 10-12) has not been measured. However, from Table 4, the HF etching rate ER of the glass substrate samples before heat treatment manufactured using comparative example glass substrate sample No. 2 is greater than the HF etching rate ERa of the glass substrate samples after heat treatment. Therefore, it is considered that the average taper angle θ2 of the glass substrate samples before heat treatment is greater than the average taper angle θ2 of the glass substrate samples after heat treatment.

[0136] Furthermore, even when the etching time was extended to 15 minutes, 30 minutes, and 45 minutes for both glass substrate samples No. 1 and 2, the average taper angle θ2 remained approximately the same. Therefore, it can be inferred that even when through holes are formed by further extending the etching time, the average taper angle θ1 of the through holes will be approximately the same angle as the average taper angle θ2 of the non-through holes. Consequently, the glass substrate samples of this embodiment can form through holes that are close to a straight shape and can be suitably used as core substrates or interposers for package substrates used in the mounting of semiconductor devices.

[0137] G0 Non-perforated glass substrate G0a First main surface G0b Second main surface G1 Perforated glass substrate G1a First main surface G1b Second main surface G2 Perforated glass substrate G2a First main surface G2b Second main surface Gm Modified area Z Thickness direction 1 Through hole 1a Side of through hole 1b Narrowed area 2 Non-through hole 2a Side of non-through hole 2b Bottom of non-through hole 3a Laser beam D1 Diameter of through hole on the first main surface D2 Diameter of through hole on the second main surface D3 Diameter of through hole in the narrowed area D4 Diameter of non-through hole on the first main surface D5 Diameter of non-through hole on the second main surface θ1 Average taper angle of through hole θ2 Taper angle of non-through hole

Claims

1. A perforated glass substrate for semiconductor packaging comprising a first main surface, a second main surface which is the opposite surface of the first main surface, and holes, wherein the holes include non-through holes formed on one of the main surfaces of the first main surface and the second main surface, and / or through holes that penetrate between the first main surface and the second main surface, and the ratio ER / ERa is 0.2 or more and less than 1 when ER is the HF etching rate of the perforated glass substrate and ERa is the HF etching rate after heat treatment of the perforated glass substrate.

2. As for the glass composition, in mol%, SiO ２ 65-85%, Al ２ O ３ 0-10%, B ２ O ３ 1-20%, Li ２ O 0-3%, Na ２ O 1-20%, K ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0-5% of O.

3. The perforated glass substrate for semiconductor packaging according to claim 1 or 2, wherein the HF etching rate ER of the perforated glass substrate is 0.65 μm / min or less.

4. The porous glass substrate for a semiconductor package according to claim 1 or 2, having an average thermal expansion coefficient in the temperature range of 30 to 380 °C of 20×10 －７ to 80×10 －７ / °C.

5. The perforated glass substrate for semiconductor packaging according to claim 1 or 2, wherein the side surface of the hole is inclined with respect to the thickness direction of the plate, and the average taper angle of the side surface is greater than 0° and 4° or less.

6. The perforated glass substrate for semiconductor packaging according to claim 1 or 2, wherein the diameter of the holes on the main surface is 5 μm or more and 200 μm or less.

7. The perforated glass substrate for semiconductor packaging according to claim 1 or 2, wherein the hole comprises the through hole, and the through hole has a constricted portion in the center of the thickness direction of the glass substrate, the constricted portion having a smaller diameter than the diameter of the through hole on the first main surface and the second main surface, and the diameter of the constricted portion is 5% or more and 99% or less of the diameter of the through hole on the first main surface and the diameter of the through hole on the second main surface.

8. The perforated glass substrate for semiconductor packaging according to claim 1 or 2, wherein the side surface of the hole is an etched surface.

9. A glass substrate for semiconductor packaging used in the manufacture of perforated glass substrates for semiconductor packaging, characterized in that, when the HF etching rate of the glass substrate is ER and the HF etching rate after heat treatment of the glass substrate is ERa, ER / ERa is 0.2 or more and less than 1.

10. As for the glass composition, in mol%, SiO ２ 65-85%, Al ２ O ３ 0-10%, B ２ O ３ 1-20%, Li ２ O 0-3%, Na ２ O 1-20%, K ２ A glass substrate for semiconductor packaging according to claim 9, containing 0-5% of O.

11. A method for manufacturing a perforated glass substrate for semiconductor packaging, comprising: a preparation step of preparing a glass substrate for semiconductor packaging according to claim 9 or 10; a laser irradiation step of irradiating a portion of the glass substrate where holes are to be formed with laser light to form a modified portion; and an etching step of etching the glass substrate having the modified portion to form holes.

12. A method for manufacturing a perforated glass substrate for semiconductor packaging, comprising: a preparation step of preparing a glass substrate; a laser irradiation step of irradiating a portion of the glass substrate where holes are to be formed with laser light to form a modified portion; and an etching step of etching the glass substrate having the modified portion to form holes, wherein the preparation step comprises a molding step of forming the glass substrate from molten glass and a cooling step of cooling the molded glass substrate, characterized in that the average cooling rate in the temperature range of (strain point Ps - 10°C) to (slow cooling point Ta + 200°C) is 1°C / second or more.

13. A method for manufacturing a glass substrate for semiconductor packaging, comprising a molding step of forming a glass substrate from molten glass, and a cooling step of cooling the molded glass substrate, wherein in the cooling step, the average cooling rate in the temperature range of (strain point Ps - 10°C) to (slow cooling point Ta + 200°C) is 1°C / second or more.

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