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

Abstract

The present invention addresses the problem of providing a perforated glass substrate for a semiconductor package, the perforated glass substrate having a small taper angle and being able to be provided with a through-hole having a shape that is close to a straight shape even when the perforated glass substrate contains a large amount of an alkali metal component. A perforated glass substrate G1 for a semiconductor package according to the present invention is provided with a first main surface G1a, a second main surface G1b that is on the reverse side from the first main surface G1a, and a through-hole 1 that penetrates the glass substrate between the first main surface G1a and the second main surface G1b. The perforated glass substrate G1 for a semiconductor package has a glass composition that contains, in mol%, 55-75% of SiO2, 0-20% of Al2O3, 0-15% of B2O3, 0-10% of Li2O, 5-20% of Na2O, 0-10% of K2O, 0-10% of MgO, 0-10% of CaO, 0-10% of SrO, and 0-10% of BaO.

Description

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

[0001] This invention relates to a perforated glass substrate for semiconductor packaging, a glass substrate for semiconductor packaging, and a method for manufacturing a perforated 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] To form through holes that are close to a straight shape, the SiO of the glass substrate ２ Increasing the content, Al ２ O ３ , B ２ O ３ Such SiO ２ It is known to be effective to regulate the content of glass skeleton-forming components other than (see, for example, Patent Documents 1 and 2).

[0005] Japanese Patent Publication No. 2023-018034 Japanese Special Publication No. 2022-531500

[0006] Incidentally, in order to facilitate the formation of through-holes that are close to a straight shape in a glass substrate, increasing the content of SiO in the glass deteriorates the melting property and formability, and raises the manufacturing cost. However, Patent Document 1 and Patent Document 2 do not describe the composition range of glass that can form through-holes close to a straight shape and has excellent melting property. ２ When designing glass with excellent melting property, increasing the alkali metal component may enhance the melting property. However, when etching glass containing a large amount of alkali metal component with a hydrofluoric acid-based chemical solution commonly used in the technical field of the present invention, the taper angle becomes very large, making it difficult to form through-holes close to a straight shape.

[0007] In view of the above problems, an object of the present invention is to provide a perforated glass substrate for a semiconductor package, a glass substrate for a semiconductor package, and a method for manufacturing a perforated glass substrate for a semiconductor package, which can form through-holes with a small taper angle and close to a straight shape even in glass containing a large amount of alkali metal component.

[0008] As a result of repeating various experiments, the inventor of the present invention has found that by strictly regulating the glass composition of the glass substrate, the above technical problems can be solved, and the present invention is proposed.

[0009] The perforated glass substrate for a semiconductor package of the present invention, which was created to solve the above problems, comprises a first main surface, a second main surface opposite to the first main surface, and a through-hole penetrating between the first main surface and the second main surface. The glass composition contains, in mol%, 55 - 75% of SiO, 0 - 20% of AlO, 0 - 15% of BO, 0 - 10% of LiO, 5 - 20% of NaO, 0 - 10% of KO, 0 - 10% of MgO, 0 - 10% of CaO, 0 - 10% of SrO, and 0 - 10% of BaO.

[0010] (1) A perforated glass substrate for a semiconductor package of the present invention, which was created to solve the above problems, comprises a first main surface, a second main surface opposite to the first main surface, and a through-hole penetrating between the first main surface and the second main surface. The glass composition contains, in mol%, 55 - 75% of SiO, 0 - 20% of AlO, 0 - 15% of BO, 0 - 10% of LiO, 5 - 20% of NaO, 0 - 10% of KO, 0 - 10% of MgO, 0 - 10% of CaO, 0 - 10% of SrO, and 0 - 10% of BaO. ２ 55 - 75%, Al ２ O ３ 0 - 20%, B ２ O ３ 0 - 15%, Li ２ O 0 - 10%, Na ２ O 5 - 20%, K ２ O 0 - 10%, MgO 0 - 10%, CaO 0 - 10%, SrO 0 - 10%, BaO

[0011] (2) In the configuration of (1) above, the glass composition is SiO in mol% ２ 55-75%, Al ２ O ３ 1-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ It is preferable that the mixture contains 0-10% O, 0-10% MgO, 0-10% CaO, 0-10% SrO, and 0-10% BaO.

[0012] (3) In the configuration of (1) above, the glass composition is SiO in mol% ２ 55-75%, Al ２ O ３ 1-20%, B ２ O ３ 0.1-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ O 0-10%, MgO 0-10%, CaO 0-10%, SrO 0-10%, BaO 0-10%, TiO ２ It is preferable that it contains 0 to 10%.

[0013] (4) In the configuration of (1) above, the glass composition is SiO in mol% ２ 55-70%, Al ２ O ３ 10-20%, B ２ O ３ 0-5%, Li ２ O 5-10%, Na ２ O 5-20%, K ２ It is preferable that the mixture contains 0-5% O, 0-5% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

[0014] (5) In the configuration of (1) above, the glass composition is SiO in mol% ２ 65-75%, Al ２ O ３ 0-10%, B ２ O ３ 0-15%, Li２ O 0-5%, Na ２ O 10-20%, K ２ It is preferable that the mixture contains 0-5% O, 0-5% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

[0015] (6) In the configuration of (1) above, the glass composition is SiO in mol% ２ 55-75%, Al ２ O ３ 5-15%, B ２ O ３ 0-5%, Li ２ O 0-5%, Na ２ O 10-20%, K ２ It is preferable that the mixture contains 0-5% O, 0-10% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

[0016] (7) In the configuration of (1) above, the glass composition is SiO in mol% ２ 55-75%, Al ２ O ３ 1-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ O 0-10%, MgO 0-10%, CaO 0-10%, SrO 0-10%, BaO 0-10%, Zr ２ It is preferable that it contains 0.1 to 5% of O.

[0017] (8) In any of the above configurations (1) to (7), the average coefficient of thermal expansion in the temperature range of 30 to 380°C is 6 × 10 －６ ~14 x 10 －６ It is preferable that the temperature is / ℃.

[0018] (9) In any of the above configurations (1) to (8), it is preferable that the Young's modulus is 60 GPa or more.

[0019] (10) In any of the configurations (1) to (9) above, it is preferable that the plate thickness is 0.03 mm or more and 2 mm or less, the TTV is 20 μm or less, and the amount of warpage is 60 μm or less.

[0020] (11) In any of the configurations (1) to (10) above, it is preferable that the side surface of the through hole is inclined with respect to the plate thickness direction and the average taper angle of the side surface is greater than 0° and 4° or less.

[0021] (12) In any of the configurations (1) to (11) above, the through hole preferably has a constricted portion in the center of the thickness direction of the glass substrate, with a diameter smaller than the diameter of the through hole in 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 in the first main surface and the diameter of the through hole in the second main surface.

[0022] (13) In any of the configurations (1) to (12) above, it is preferable that the diameter of the first main surface of the through hole is 5 μm or more and 200 μm or less, and the diameter of the second main surface of the through hole is 5 μm or more and 200 μm or less.

[0023] (14) In any of the above configurations (1) to (13), it is preferable that at least the inner surface of the through hole is an etched surface.

[0024] (15) The semiconductor package glass substrate of the present invention, which was devised to solve the above problems, is a semiconductor package glass substrate used in the manufacture of a glass substrate having through holes, and the glass composition is SiO in mol% ２ 55-75%, Al ２ O ３ 0-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ It is characterized by containing 0-10% O, 0-10% MgO, 0-10% CaO, 0-10% SrO, and 0-10% BaO.

[0025] (16) The present invention, which was devised to solve the above problems, is characterized by comprising: a preparation step of preparing a glass substrate for semiconductor packaging having the configuration of (15) above; a laser irradiation step of irradiating the portion of the glass substrate for semiconductor packaging where through holes are to be formed with laser light to form a modified portion; and an etching step of etching the glass substrate for semiconductor packaging having a modified portion to form a glass substrate having through holes.

[0026] (17) In the configuration of (16) above, it is preferable to use an alkaline etching solution in the etching process.

[0027] According to the present invention, even with glass containing a large amount of alkali metal components, it is possible to form through-holes with a small taper angle and a shape close to a straight hole.

[0028] Figure 1 is a top view showing a glass substrate according to one embodiment of the present invention. Figure 2 is a cross-sectional view taken along line A-A of the glass substrate in Figure 1. Figure 3 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 4 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 5 is a flow chart showing a method for manufacturing a glass substrate according to one embodiment of the present invention. Figure 6 is a perspective view showing a laser irradiation process according to one embodiment of the present invention. Figure 7 is a schematic diagram for comparing a glass substrate before and after through hole formation according to one embodiment of the present invention.

[0029] Embodiments of the present invention will be described below with reference to the drawings.

[0030] [First Embodiment] First, the glass composition and properties 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 perforated glass substrate having through holes, and is a glass substrate (non-perforated glass substrate) in the state before the through holes are formed.

[0031] The glass substrate according to the first embodiment has a glass composition of SiO in mol%. ２ 55-75%, Al２ O ３ 0 to 20%, B ２ O ３ 0 to 15%, Li ２ O 0 to 10%, Na ２ O 5 to 20%, K ２ O 0 to 10%, MgO 0 to 10%, CaO 0 to 10%, SrO 0 to 10%, BaO 0 to 10%. It is characterized by containing the above. 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 % indication represents mol% unless otherwise specified.

[0032] SiO ２ is a component that forms the skeleton of the glass. SiO ２ If the content of is too small, the glass composition becomes unstable, devitrification problems occur during glass forming, and productivity is significantly reduced. Also, when the glass devitrifies, the glass substrate becomes cloudy and the transmittance of the glass substrate decreases. As a result, when the glass substrate is irradiated with a laser to form a modified portion, the laser light is scattered, and it becomes difficult to form a modified portion particularly in the central portion in the plate thickness direction. Then, when removing the modified portion by etching, the central portion in the plate thickness direction is more difficult to remove compared to the vicinity of the main surface of the glass substrate, the taper angle of the through hole or non-through hole becomes large, and it becomes difficult to form a through hole or non-through hole close to a straight shape. Therefore, the lower limit of SiO ２ is 55% or more, preferably 57% or more, more preferably 58% or more, more preferably 63% or more, particularly preferably 65% or more. On the other hand, if the content of SiO ２ is too large, the high-temperature viscosity increases, the amount of heat required during melting increases, the melting cost rises, and there is a risk of residue of the introduced raw material of SiO ２ occurring, which may cause a decrease in yield. Also, cristobalite is likely to precipitate during forming. Therefore, the upper limit of SiO ２ is 75% or less, preferably 73% or less, more preferably 71% or less, more preferably 70% or less, particularly preferably 67% or less.

[0033] Al ２ O ３ is a component that forms the skeleton of the glass. Al２ O ３ If the content of O is too low, the rigidity of the substrate will decrease. Especially when used as the core substrate of a package, the rigidity of the substrate is one of the important properties. Therefore, Al ２ O ３ The lower limit amount of O is 0% or more, preferably 1% or more, more preferably 4% or more, more preferably 7% or more, more preferably 10% or more, and particularly preferably 11% or more. On the other hand, if the content of Al ２ O ３ is too high, the high-temperature viscosity will increase, and the melting property and formability will be likely to decrease. Therefore, the upper limit amount of Al ２ O ３ is 20% or less, preferably 18% or less, more preferably 15% or less, and more preferably 13% or less. Also, from the viewpoint of particularly emphasizing the melting property of the glass, the upper limit amount of Al ２ O ３ is preferably 12% or less, more preferably 11% or less, and particularly preferably 10% or less.

[0034] B ２ O ３ is a component that forms the skeleton of the glass and is also a component that reduces the high-temperature viscosity. If the content of B ２ O ３ is too low, the high-temperature viscosity will increase, and the melting property and formability will be likely to decrease. Therefore, the lower limit amount of B ２ O ３ is 0% or more, preferably 0.1% or more, more preferably 0.3% or more, more preferably 0.6% or more, more preferably 2% or more, and particularly preferably 4% or more. On the other hand, B ２ O ３If the content is too high, the rigidity of the substrate decreases, and the glass becomes more prone to phase separation. As mentioned above, when used as a core substrate for a package, the rigidity of the substrate is one of the important characteristics. Also, when the glass phases separate, 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 to form the modified area, the laser light is scattered, making it difficult to form the modified area. Consequently, when removing the modified area by etching, the central part in the thickness direction of the glass substrate is more difficult to remove than the vicinity of the main surface, the taper angle of the through-hole or non-through-hole becomes larger, and it becomes difficult to form through-hole or non-through-hole that are close to a straight shape. Therefore, B ２ O ３ The upper limit of the amount is 15% or less, preferably 13% or less, more preferably 10% or less, more preferably 9% or less, more preferably 7% or less, more preferably 6% or less, and particularly preferably 5% or less.

[0035] Li ２ O is a component that reduces the high-temperature viscosity of glass and increases its meltability. Li ２ If 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 the amount of O is 0% or more, preferably 0.01% or more, more preferably 0.05% or more, more preferably 0.1% or more, and particularly preferably 1% or more. Furthermore, from the viewpoint of particularly emphasizing meltability, LiO ２ The lower limit of is 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, and particularly preferably 7% or more. On the other hand, Li ２ If the O content is too high, batch costs increase, and manufacturing costs rise. Also, the glass becomes more prone to phase separation, and the transmittance of the glass substrate decreases. As a result, when a laser is irradiated onto the glass substrate to form the modified area, the laser light scatters, making it difficult to form the modified area. Consequently, when removing the modified area by etching, the central part in the thickness direction of the glass substrate is more difficult to remove than the vicinity of the main surface, the taper angle of the through-holes or non-through-holes becomes larger, and it becomes difficult to form through-holes or non-through-holes that are close to a straight shape. Therefore, Li ２The upper limit of O is 10% or less, preferably 9% or less, more preferably 8% or less, more preferably 7.5% or less, more preferably 7.3% or less, more preferably 7% or less, more preferably 6% or less, and particularly preferably 5% or less.

[0036] 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 5% or more, preferably 6% or more, more preferably 7% or more, more preferably 10% or more, and particularly preferably 12% or more. On the other hand, Na ２ If the O content is too high, the coefficient of thermal expansion will increase, which may lead to excessive deformation of the glass substrate during semiconductor device mounting and potentially cause the glass substrate to break. Therefore, Na ２ The upper limit of O is 20% or less, preferably 19% or less, more preferably 18% or less, more preferably 17% or less, and particularly preferably 16.5% or less.

[0037] K ２ O is a component that reduces the high-temperature viscosity of glass and increases its meltability. 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 0% or 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, K ２ If the O content is too high, the coefficient of thermal expansion increases, which can lead to excessive deformation of the glass substrate during semiconductor device mounting and potentially cause the glass substrate to break. Furthermore, dielectric loss increases, making it easier for the device characteristics of the glass substrate to deteriorate. Therefore, K ２ The upper limit of O is 10% or less, preferably 9% or less, more preferably 8% or less, more preferably 6% or less, more preferably 5% or less, and particularly preferably 3% or less.

[0038] MgO is an optional component that increases rigidity, reduces the high-temperature viscosity of the glass, and improves meltability; its content may be 0%. If the MgO content is too low, rigidity tends to decrease. Also, the high-temperature viscosity increases, which tends to decrease meltability and moldability. Therefore, the lower limit of MgO is 0% or more, preferably 0.1% or more, more preferably 0.2% or more, more preferably 0.5% or more, and particularly preferably 0.9% 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 to form the modified area, the laser light is scattered, making it difficult to form the modified area. Consequently, when the modified area is removed by etching, the central part in the thickness direction of the glass substrate is more difficult to remove than the vicinity of the main surface, the taper angle of the through-holes or non-through-holes becomes larger, and it becomes difficult to form through-holes or non-through-holes that are close to a straight shape. Therefore, the upper limit of MgO is 10% or less, preferably 9% or less, more preferably 7% or less, and particularly preferably 5% or less.

[0039] CaO is an optional component used to reduce the high-temperature viscosity of the glass and improve its meltability, and its content may be 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 the CaO content is 0% or more, preferably 0.1% or more, more preferably 0.8% or more, and particularly preferably 1.7% or more. On the other hand, if the CaO content is too high, the balance of the composition will be disrupted, devitrification will increase, productivity will decrease, and the coefficient of thermal expansion may increase. Therefore, the upper limit of the CaO content is 10% or less, preferably 9% or less, more preferably 6% or less, more preferably 5% or less, and particularly preferably 4% or less.

[0040] SrO is an optional component that reduces the high-temperature viscosity of the glass and improves its meltability, and its content may be 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 0% or more, preferably 0.01% or more, more preferably 0.08% or more, and more preferably 0.15% or more. On the other hand, if the SrO content is too high, the coefficient of thermal expansion will increase, which may lead to greater deformation of the glass substrate during semiconductor device mounting and potentially cause the glass substrate to break. Therefore, the upper limit of SrO is preferably 10% or less, more preferably 5% or less, more preferably 4% or less, and particularly preferably 2% or less.

[0041] BaO is an optional component that reduces the high-temperature viscosity of the glass and improves its meltability, and its content may be as low as 0%. It is also a component that improves 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 0% or more, preferably 0.1% or more, more preferably 0.9% or more, and particularly preferably 1.8% or more. On the other hand, if the BaO content is too high, the coefficient of thermal expansion increases, which may lead to greater deformation of the glass substrate during semiconductor device mounting and potentially cause the glass substrate to break. Therefore, the upper limit of the BaO content is 10% or less, preferably 6% or less, more preferably 5% or less, and particularly preferably 3% or less.

[0042] 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 0.2% or more, more preferably 0.5% or more, and particularly preferably 1% 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, which may lead to greater deformation of the glass substrate during semiconductor device mounting and potentially cause the glass substrate to break. Therefore, the upper limit range for the total content of MgO, CaO, SrO, and BaO is preferably 10% or less, more preferably 8% or less, more preferably 7% or less, and more preferably 6% or less.

[0043] SnO ２SnO 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 ２ It is preferable to increase the content of SnO to enhance the clarification effect and reduce the amount of foam. ２ The lower limit of the amount is preferably 0% or more, more preferably 0.02% or more, more preferably 0.05% or more, and particularly preferably 0.07% or more. On the other hand, SnO ２ If the content is too high, SnO ２ Devitrified crystals are more likely to precipitate, which may lead to a decrease in yield. Therefore, SnO ２ The upper limit of the amount is preferably 1% or less, more preferably 0.9% or less, more preferably 0.7% or less, and particularly preferably 0.5% or less.

[0044] As described above, SnO ２ While is suitable as a clarifying agent, as long as the glass properties are not impaired, SnO ２ Instead, or SnO ２ Along with F, SO ３ Metal powders such as C, Al, or Si can be added in amounts up to 0.5% each (preferably up to 0.4%, particularly preferably up to 0.3%). In addition, CeO can be used as a clarifying agent. ２ It can also be added, but CeO ２ If the content is too high, the glass will become discolored, and when the glass substrate is irradiated with a laser to form the modified area, the heat generated at the laser irradiation area will be excessive, making it easier for defects such as cracks to occur. For this reason, CeO ２ The upper limit is preferably 0.5% or less, more preferably 0.4% or less, and particularly preferably 0.3% or less.

[0045] Cl is an optional component used to promote the initial melting of the glass batch, and its content may be as low as 0%. Adding Cl can also enhance the action of the clarifying agent. As a result, the melting cost can be reduced while extending the lifespan of the glass manufacturing furnace. Therefore, the lower limit of Cl is preferably 0% or more, more preferably 0.001% or more, more preferably 0.002% or more, more preferably 0.003% or more, and particularly preferably 0.0035% or more. On the other hand, if the Cl content is too high, the strain point tends to decrease, which may lead to a decrease in peel strength and deformation of the glass substrate during the heat treatment process in the plating process. Therefore, the upper limit of Cl is preferably 0.01% or less, more preferably 0.009% or less, more preferably 0.008% or less, and particularly preferably 0.007% or less. For example, NaCl can be used as a raw material for introducing Cl. Furthermore, since Cl is a volatile component during melting, the Cl content in the batch may be appropriately adjusted during manufacturing so that the amount of Cl in the molded glass substrate satisfies the above range.

[0046] As a clarifying agent, ２ O ３ Sb ２ O ３ This is also effective. However, As ２ O ３ Sb ２ O ３ These are components that increase the environmental burden. Therefore, it is preferable that the glass substrate according to this embodiment substantially does not contain these components, and the range is preferably 0 to 0.1%.

[0047] In this embodiment, the glass substrate uses SnO as a clarifying agent to promote clarification and reduce melting costs. ２ Preferably, the mixture contains at least one of the following: , and chlorine.

[0048] In addition to the above components, the following components may be added as optional components. From the viewpoint of effectively enjoying the effects of the present invention, the total amount of other components is preferably 5% or less, and particularly preferably 4% or less.

[0049] 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 of the amount is preferably 10% or less, more preferably 5% or less, more preferably 1% or less, more preferably 0.5% or less, more preferably 0.1% or less, more preferably 0.05% or less, more preferably 0.03% or less, more preferably 0.02% or less, more preferably 0.01% or less, more preferably 0.009% or less, more preferably 0.008% or less, more preferably 0.007% or less, and particularly preferably 0.006% or less.

[0050] 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 0.2% or more, and particularly preferably 0.3% 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 portion, 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 0.81% or less.

[0051] P ２ O ５ This is an optional component that has the effect of improving the productivity of glass by suppressing Al-based devitrification crystals, and its content may be 0%. Therefore, P ２ O ５ The lower limit of P is preferably 0% or more, more preferably 0.1% or more, and particularly preferably 0.2% or more. On the other hand, P ２ O ５When 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 to form the modified area, the laser light is scattered, making it difficult to form the modified area. Therefore, P ２ O ５ The upper limit is preferably 5% or less, more preferably 4.9% or less, more preferably 4.8% or less, and particularly preferably 4.5% or less.

[0052] CuO is an optional component for coloring the glass, and its content may be 0%. If the CuO content is too high, the glass substrate will be colored, and when the glass substrate is irradiated with a laser to form the modified area, the heat generated at the laser irradiation area will be large, making it easier for defects such as cracks to occur. Therefore, it is desirable to have a low CuO content, and its upper limit is preferably 1% or less, more preferably less than 0.5%, and more preferably 0.2% or less. The lower limit of CuO may be, for example, 0.01% or more.

[0053] 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 total 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 for the total amount and individual content are preferably 1% or less, more preferably 0.5% or less, more preferably 0.3% or less, and more preferably less than 0.1%. ２ O ３ , Nb ２ O ５ La ２ O ３ The lower limit range for the total amount and individual content may be, for example, 0.01% or more.

[0054] Fe ２ O ３Fe 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 ３ If the content is too high, 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 be large, 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.

[0055] ZrO ２ This is an optional component that has the effect of improving alkali resistance, and its content may be 0%. If it is necessary to obtain a pore shape close to straight, ZrO ２ By including a large amount of ZrO, it becomes easier to obtain a straighter pore shape. ２ The lower limit of is preferably 0% or more, more preferably 0.01% or more, more preferably 0.05% or more, and particularly preferably 0.1% or more. On the other hand, it is also a component that is inevitably mixed in from the refractories used in glass manufacturing furnaces, and ZrO ２ If the content is too high, devitrified crystals are more likely to precipitate. Therefore, ZrO ２ The upper limit of the amount is preferably 5% or less, more preferably 4% or less, more preferably 3% or less, more preferably 2% or less, and particularly preferably 1% or less.

[0056] The lower limit of the average thermal expansion coefficient CTE in the temperature range of 30 to 380°C is preferably 6 × 10⁻⁶ －６ / ℃ or higher, more preferably 6.3 × 10 －６ / ℃ or higher, more preferably 6.4 × 10 －６ / ℃ or higher, particularly preferably 6.5 × 10 －６ It is above / °C. Furthermore, the average coefficient of thermal expansion CTE in the temperature range of 30 to 380°C is preferably 14 × 10⁻⁶. －６ / ℃ or lower, more preferably 10 × 10 －６ / ℃ or lower, more preferably 9.5 × 10 －６ / °C or lower, particularly preferably 8 x 10 －６ The temperature is below / °C. This makes it easier to match the thermal expansion coefficient of the build-up layer of the printed circuit board when mounting semiconductor elements, and reduces the likelihood of deformation of the glass substrate.

[0057] The lower limit of Young's modulus is preferably 60 GPa or higher, more preferably 63 GPa or higher, more preferably 69 GPa or higher, and particularly preferably 71 GPa or higher. This suppresses the occurrence of defects caused by deformation of the glass substrate during the mounting of semiconductor elements.

[0058] The lower limit of the strain point is preferably 500°C or higher, more preferably 510°C or higher, more preferably 520°C or higher, and particularly preferably 550°C or higher. With such a strain point, the peel strength can be increased by raising the heat treatment temperature in the plating process on the glass substrate, and deformation of the substrate during heat treatment can be suppressed.

[0059] The lower limit of the softening point is preferably 1000°C or lower, more preferably 950°C or lower, more preferably 800°C or lower, and particularly preferably 750°C or lower. With such a softening point, the process temperature when performing heat treatment to improve the plate quality and phase separation state of the glass substrate can be lowered, thereby reducing manufacturing costs.

[0060] The upper limit of the liquidus temperature is preferably 1200°C or less, more preferably less than 1150°C, more preferably 1100°C or less, and particularly preferably 900°C or less. 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. Note that the liquidus temperature is an indicator of devitrification resistance; the lower the liquidus temperature, the better the devitrification resistance.

[0061] The lower limit of 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, particularly preferably 10 ４．６The viscosity is dPa·s or higher. This reduces the likelihood of devitrification during molding and lowers 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.

[0062] High temperature viscosity 10 ２．５ The upper limit of the temperature in dPa·s is preferably 1620°C or lower, more preferably 1600°C or lower, more preferably 1500°C or lower, and particularly preferably 1400°C or lower. This makes it easier to melt the glass batch and reduces the manufacturing cost of the glass substrate. Also, B from molten glass ２ O ３ or Na ２ The amount of O evaporated is reduced, making it less likely for a heterogeneous layer to form on the molten glass surface, thus improving the homogeneity of the glass. Note that the high-temperature viscosity is 10 ２．５ The temperature in dPa·s corresponds to the melting temperature, and the lower this temperature, the better the meltability.

[0063] In this embodiment, the glass substrate is preferably formed by the overflow downdraw method. 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 the 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, and the overflowed molten glass is allowed to flow down both sides of the heat-resistant structure and then merge at the lower end of the heat-resistant structure. The glass ribbon obtained in this way is pulled downward and stretched, a glass plate is cut from the glass ribbon, and a glass substrate is manufactured by processing such as cutting, edge processing, cleaning, inspection, and packaging. 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, so it becomes a forged surface. For this reason, a glass substrate with good surface quality without polishing can be manufactured inexpensively, and thinning is also easy. Glass substrates formed by the overflow downdraw method have a mating surface in the middle of the thickness direction.

[0064] In addition to the overflow downdraw method, glass substrates can also be formed using other methods such as the slot downdraw method, float method, and rollout method.

[0065] The lower limit of 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. The thicker the substrate, the less likely the glass substrate is to deform, and the less likely problems are to occur when mounting semiconductor elements. The upper limit of 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. The thinner the substrate, the smaller the diameter of the through-holes can be made. By making the diameter of the through-holes smaller, the mounting density of semiconductor elements on the glass substrate can be increased, and fine wiring can be formed. The thickness of the glass substrate can be adjusted by controlling the flow rate and traction speed during molding. Furthermore, processes such as slimming may be performed to adjust the thickness of the glass substrate.

[0066] The upper limit of 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. The smaller the TTV, the higher the surface accuracy and the easier it is to improve the accuracy of the processing. In particular, it is possible to improve the 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 upper limit of the warp 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 warp is not particularly limited, but may be, for example, 1 μm or more, or 5 μm or more. The smaller the warp, the easier it is to improve the accuracy of the processing. In particular, it is possible to improve the accuracy of the wiring, making high-density wiring possible. Here, "warp" refers to the sum of the absolute value of the maximum distance between the highest point and the least-squares focal plane on the entire glass substrate 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 upper limit of the relative permittivity of the glass substrate at 25°C and a frequency of 10 GHz is preferably 9.9 or less, more preferably 8.5 or less, more preferably 8.0 or less, and particularly preferably 7.5 or less. This reduces the transmission loss when an electrical signal is transmitted to the glass substrate when it is used in a high-frequency device.

[0069] The upper limit of the dielectric loss tangent of the glass substrate at 25°C and a frequency of 10 GHz is preferably 0.1 or less, more preferably 0.09 or less, more preferably 0.08 or less, and particularly preferably 0.07 or less. This reduces the transmission loss when an electrical signal is transmitted to the glass substrate when it is used in a high-frequency device.

[0070] The lower limit of the linear transmittance of the glass substrate in the wavelength range of 400 nm to 1100 nm according to this embodiment is preferably 80% or higher, more preferably 85% or higher, and particularly preferably 90% or higher. 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, making it less likely for defects such as cracks to occur. Alternatively, if the influence of phase separation of the glass is small 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. It is not necessary for the above preferred range of transmittance to be satisfied for the entire wavelength range of 400 nm to 1100 nm; it is sufficient if the above preferred range of transmittance is satisfied for the wavelength of the laser light used. If the wavelength of the laser light used changes, it is preferable that the above preferred range of transmittance be satisfied for the entire wavelength range of 400 nm to 1100 nm.

[0071] The glass substrate according to this embodiment is used in semiconductor packages, specifically in package substrates used for mounting semiconductor elements. It is preferable to use it to manufacture glass substrates having through holes (perforated glass substrates). Perforated glass substrates manufactured using the glass substrate according to this embodiment are particularly preferable for use as interposers or core substrates in semiconductor package substrates. The glass substrate according to this embodiment is suitable for forming through holes that are close to a straight shape, has excellent productivity, and is less prone to deformation of the substrate when semiconductor elements are mounted, making it suitable for applications such as interposers and core substrates.

[0072] [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 is a glass substrate having 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.

[0073] Figure 1 is a top view showing a perforated glass substrate G1 according to this embodiment, and Figure 2 is a cross-sectional view of the perforated glass substrate G1 of Figure 1 taken along line A-A. As shown in Figures 1 and 2, 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.

[0074] Figure 3 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 perforated through-hole 1 on the first main surface G1a and the diameter D2 of the through-hole 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 it from the cross-sectional direction with a transmission optical microscope while focusing 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.

[0075] The upper limits of the diameters D1 and D2 of the through holes 1 in the first main surface G1a and the second main surface G1b 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 through holes 1 at high density, and when the perforated glass substrate G1 is used in the manufacture of core substrates or interposers, the wiring density can be increased. On the other hand, if the diameters D1 and D2 of the through holes 1 are too small, voids may be formed in the conductive material when a conductive part is formed inside the through holes 1 by plating, which may cause a problem in which there is no electrical connection between the first main surface G1a and the second main surface G1b of the perforated glass substrate G1. Therefore, the lower limit values ​​of the diameters D1 and D2 of the through hole 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 21 μm or more, more preferably 22 μm or more, more preferably 23 μm or more, more preferably 24 μm or more, more preferably 25 μm or more, and particularly preferably 30 μm or more. This ensures that the above-mentioned problems are reliably prevented.

[0076] The upper limit of the ratio of the diameter D3 of the constricted portion 1b to the diameters D1 and D2 of the through hole 1 (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. The lower limit of 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, more preferably 50% or more, more preferably 55% or more, more preferably 60% or more, more preferably 65% ​​or more, more preferably 70% or more, more preferably 75% or more, and particularly preferably 80% 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 of the perforated glass substrate G1.

[0077] 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

[0078] Next, the average taper angle θ1 of the through hole 1 is calculated using the following equation 3: θ1 = (θ1a + θ1b) / 2 Equation 3

[0079] The upper limit of 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, more preferably 2.3° or less, more preferably 2° or less, more preferably 1.8° or less, more preferably 1.5° or less, more preferably 1.3° or less, more preferably 1° or less, and particularly preferably 0.8° or less. This allows for the formation of high-density through-holes 1, and when the perforated 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 0.1° or more, more preferably 0.2° or more, more preferably 0.3° or more, more preferably 0.4° or more, more preferably 0.5° or more, more preferably 0.6° or more, and particularly preferably 0.7° 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 of the perforated glass substrate G1.

[0080] Figure 4 is a schematic cross-sectional view showing a second example of a through-hole 1 formed in a perforated glass substrate G1 according to this embodiment. As shown in Figure 4, 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.

[0081] The taper angle θ3 of the through hole 1 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

[0082] 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.

[0083] [Third Embodiment] Next, a method for manufacturing a perforated glass substrate according to the third embodiment of the present invention will be described with reference to Figures 5 to 8. As shown in Figure 5, the method for manufacturing a perforated glass substrate according to this embodiment comprises a preparation step S1 for preparing a glass substrate (non-perforated glass substrate) G0, a laser irradiation step S2 for irradiating the portion of the glass substrate G0 where through holes are to be formed with laser light to form a modified portion Gm, and an etching step S3 for etching the glass substrate G0 having the modified portion Gm to form a glass substrate having through holes.

[0084] In preparation step S1, 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 downdraw method to a predetermined size. Alternatively, a glass plate formed by other methods such as the slot downdraw method, float method, or rollout method may be cut to a predetermined size.

[0085] In the laser irradiation process S2, as shown in Figure 6, 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).

[0086] 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.

[0087] 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.

[0088] 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 it is particularly preferable to use a Bessel beam shape. By shaping the laser beam 3a into a Bessel beam shape, a modified portion Gm can be formed over the entire thickness direction of the glass substrate G0 with a single laser irradiation, 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.

[0089] 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.

[0090] In etching step S3, the glass substrate G0 on which the modified portion Gm was formed in the laser irradiation step S2 is immersed in an etching solution to remove the modified portion Gm and form a through hole 1. In this embodiment, an alkaline etching solution such as an aqueous NaOH solution or an aqueous KOH solution is used as the etching solution. A surfactant may also be added to the etching solution. In etching step S3, after the modified portion Gm is removed and the through hole 1 is formed, the diameter of the through hole 1 may be widened by etching away the unmodified portion around the modified portion Gm until the diameter of the through hole 1 reaches a desired value.

[0091] The temperature of the etching solution is not particularly limited, but to improve productivity, it is preferable to raise the temperature of the alkaline etching solution as much as possible. When using an aqueous NaOH solution as the etching solution, the lower limit of the etching solution temperature is preferably 70°C or higher, more preferably 80°C or higher, more preferably 90°C or higher, more preferably 100°C or higher, more preferably 110°C or higher, and particularly preferably 120°C or higher. Raising the temperature of the etching solution increases the etching rate, enabling efficient production. The upper limit of the etching solution temperature is preferably 140°C or lower, more preferably 135°C or lower, and particularly preferably 130°C or lower. By setting the temperature in this way, temperature unevenness in the etching solution can be reduced, and the TTV of the glass substrate after etching can be lowered. Furthermore, by increasing the pressure inside the etching container, the boiling point of the etching solution can be raised, and the glass substrate can be etched at a temperature above the boiling point of the etching solution under atmospheric pressure.

[0092] Furthermore, an alkaline chemical solution may be used as the etching solution to create a through-hole 1 that is close to a straight shape; for example, an aqueous solution of NaOH or an aqueous solution of KOH can be used. The etching solution may also be a mixed aqueous solution by adding one or more alkali metal hydroxides such as NaOH and KOH, or a surfactant may be added. The concentration of the etching solution in this case is not particularly limited and may be changed as appropriate to obtain the desired shape of the through-hole 1, but it is preferable to increase the concentration of alkali metal hydroxide in the etching solution in order to shorten the etching time required to form the through-hole. For example, in the case of an aqueous solution of NaOH, it is preferable to use an aqueous solution containing 30% by mass or more of NaOH, and it is more preferable to use an aqueous solution containing 40% by mass or more of NaOH. Furthermore, the concentration of the etching solution may be changed during the formation of the through-hole 1. Note that since the concentration of the etching solution changes during the execution of etching step S3, it is preferable to circulate or replace the etching solution to keep the concentration of the etching solution constant.

[0093] In etching step S3, 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 angle θ1 of the through-hole 1 tends to decrease.

[0094] Figure 7 is a schematic diagram for comparing the glass substrate G0 before etching process S3 and the perforated glass substrate G1 after etching process S3. In Figure 7, the glass substrate G0 before etching process S3 is shown by a dashed line. As shown in Figure 7, in etching process S3, the first main surface G0a, the second main surface G0b, or both the first main surface G0a and the second main surface G0b are etched, so the thickness t of the perforated glass substrate G1 after through-hole formation is smaller than the thickness t0 of the glass substrate G0 before through-hole formation.

[0095] Furthermore, in this embodiment, since the through-holes 1 are formed in the glass substrate G1 by the etching process S3, at least the side surface 1a of the through-hole 1 (inside the through-hole 1) and one of the main surfaces are etched surfaces. As a result, the inside of the through-hole 1 and one of the main surfaces have excellent surface properties, are free of fine cracks, and have high strength. Therefore, by using the perforated glass substrate G1 according to this embodiment as a core substrate or interposer, a package substrate that is resistant to damage can be obtained. On the other hand, when through-holes are formed in a glass substrate by methods such as laser abrasion, the surface properties inside the through-holes are poor, and fine cracks are more likely to occur, resulting in lower strength.

[0096] In etching step S3, 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 S3 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.

[0097] 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.

[0098] Tables 1 and 2 show the glass composition and glass properties of the examples of the present invention (samples No. 1-4, No. 6-8) and comparative example (sample No. 5).

[0099] First, glass batches prepared with glass raw materials to achieve the glass composition shown in the table were placed in a platinum crucible and melted at 1400-1600°C for 24 hours. During the melting of the glass batches, a platinum stirrer was used to stir and homogenize them. Next, 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 obtained sample, 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. ４．０ Temperature and high-temperature viscosity at dPa·s 10 ３．０ Temperature and high-temperature viscosity at dPa·s 10 ２．５ Temperature, liquidus temperature TL, and viscosity log at dPa·s １０ The ηTL and linear transmittance at wavelengths of 400 nm to 800 nm were evaluated.

[0100]

[0101]

[0102] The density was measured using the well-known Archimedes method.

[0103] The average thermal expansion coefficient CTE in the temperature range of 30 to 380°C is the value measured using a dilatometer.

[0104] Young's modulus is a value measured using a well-known resonance method.

[0105] The strain point Ps, annealing point Ta, and softening point Ts were measured according to the ASTM C336 and C338 methods.

[0106] High temperature viscosity 10 ４．０ dPa·s, 10 ３．０ dPa·s, 10 ２．５The temperature in dPa·s was measured using the platinum ball pulling method.

[0107] The liquidus temperature TL is the temperature at which crystals precipitate after the glass powder that passes through a standard 30-mesh (500 μm) sieve and remains in a 50-mesh (300 μm) sieve is placed in a platinum boat and held in a temperature gradient furnace for 24 hours.

[0108] liquidus viscosity log １０ ηTL is the viscosity of the glass at the liquidus temperature TL, measured using the platinum ball pulling method.

[0109] The linear transmittance in the wavelength range of 400 nm to 800 nm was obtained by preparing a 0.5 mm thick plate sample with both sides mirror-polished, and measuring the linear transmittance of this sample using an ultraviolet-visible-near-infrared spectrophotometer (JASCO V-670).

[0110] Next, through-holes were formed in glass substrate samples No. 4 and 5 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 the irradiation positions spaced approximately 200 μm apart, thereby forming approximately 8,000 modified areas on the glass substrate.

[0111] Next, the glass substrate sample was etched under the following conditions. The glass substrate sample was placed in a stainless steel container containing the etching solution, and etching was performed. A 48% by mass aqueous solution of NaOH was used as the etching solution at 100°C.

[0112] The glass substrate samples obtained by this method had through-holes with constricted sections formed inside. The average taper angle θ of these through-holes was determined by the method described above.

[0113] Table 3 shows the etching time, the thickness t0 of the glass substrate sample before etching, the thickness t of the glass substrate sample after etching, the thickness reduction Δt(t0-t), the shape of the through-hole, and the etching rate.

[0114] The etching rate was calculated by dividing the reduction in plate thickness due to etching (plate thickness of the glass substrate before etching - plate thickness of the glass substrate after etching) by the etching time.

[0115]

[0116] Next, through-holes were formed in glass substrate samples No. 1-5, 7, and 8 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. Etching was then performed on this glass substrate using an aqueous solution containing 30% by mass of NaOH as the etching solution, at an etching solution temperature of 80°C.

[0117] The perforated glass substrate samples obtained by this method had through-holes with constricted sections inside. The average taper angle θ1 of the through-holes was determined by the method described above.

[0118] Table 4 shows the etching time, the thickness t0 of the glass substrate sample before etching, the thickness t of the glass substrate sample after etching, the thickness reduction Δt(t0-t), the shape of the through-hole, and the etching rate.

[0119]

[0120] Tables 1 and 2 show that glass substrate samples No. 1-4 and 6-8 of the examples have strain points, slow cooling points, softening points, and high-temperature viscosity 10. ４．０ It was confirmed that the temperature at dPa·s was low and productivity was excellent. Furthermore, glass substrate samples No. 2 and 3 of the example had a high-temperature viscosity of 10 ３．０ dPa·s, 10 ２．５ The temperature at dPa·s was also low, and it was confirmed that it had superior productivity. On the other hand, comparative example glass substrate sample No. 5 showed a strain point, slow cooling point, softening point, and high-temperature viscosity of 10. ４．０ dPa·s, 10 ３．０ dPa·s, 10 ２．５It was confirmed that the temperature at dPa·s was high, resulting in poor productivity. Furthermore, as shown in Tables 3 and 4, the glass substrate samples with through holes manufactured using glass substrate samples No. 1-4 and 7-8 of this embodiment had a small average taper angle and formed through holes that were close to straight. On the other hand, the glass substrate sample with through holes manufactured using glass substrate sample No. 5 of the comparative example had a large average taper angle and did not form through holes that were close to straight. Therefore, it was confirmed that the glass substrate samples of this embodiment are suitable for use as core substrates and interposers for package substrates used in the mounting of semiconductor devices.

[0121] G0 Non-porous glass substrate G0a First main surface G0b Second main surface G1 Perforated glass substrate G1a First main surface G1b Second main surface Gm Modified area Z Thickness direction 1 Through hole 1a Side surface of through hole 1b Narrowed area 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 θ1 Average taper angle of the 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 a through hole penetrating between the first main surface and the second main surface, wherein the glass composition is SiO2 in mol%. ２ 55-75%, Al ２ O ３ 0-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ A perforated glass substrate for semiconductor packaging, characterized by containing 0-10% O, 0-10% MgO, 0-10% CaO, 0-10% SrO, and 0-10% BaO.

2. As a glass composition, in mol%, SiO ２ 55 to 75%, Al ２ O ３ 1 to 20%, B ２ O ３ 0 to 15%, Li ２ O 0 to 10%, Na ２ O 5 to 20%, K ２ O 0 to 10%, MgO 0 to 10%, CaO 0 to 10%, SrO 0 to 10%, BaO 0 to 10%, the porous glass substrate for a semiconductor package according to claim 1.

3. As for the glass composition, in mol%, SiO ２ 55-75%, Al ２ O ３ 1-20%, B ２ O ３ 0.1-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ O 0-10%, MgO 0-10%, CaO 0-10%, SrO 0-10%, BaO 0-10%, TiO ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0 to 10%.

4. As for the glass composition, in mol%, SiO ２ 55-70%, Al ２ O ３ 10-20%, B ２ O ３ 0-5%, Li ２ O 5-10%, Na ２ O 5-20%, K ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0-5% O, 0-5% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

5. As for the glass composition, in mol%, SiO ２ 65-75%, Al ２ O ３ 0-10%, B ２ O ３ 0-15%, Li ２ O 0-5%, Na ２ O 10-20%, K ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0-5% O, 0-5% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

6. As for the glass composition, in mol%, SiO ２ 55-75%, Al ２ O ３ 5-15%, B ２ O ３ 0-5%, Li ２ O 0-5%, Na ２ O 10-20%, K ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0-5% O, 0-10% MgO, 0-5% CaO, 0-5% SrO, and 0-5% BaO.

7. As for the glass composition, in mol%, SiO ２ 55-75%, Al ２ O ３ 1-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ O 0-10%, MgO 0-10%, CaO 0-10%, SrO 0-10%, BaO 0-10%, Zr ２ A perforated glass substrate for semiconductor packaging according to claim 1, containing 0.1 to 5% of O.

8. The average coefficient of thermal expansion in the temperature range of 30 to 380°C is 6 × 10⁻⁶. －６ ~14 x 10 －６ A perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the temperature is / °C.

9. A perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the Young's modulus is 60 GPa or higher.

10. A perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the plate thickness is 0.03 mm or more and 2 mm or less, the TTV is 20 μm or less, and the warpage is 60 μm or less.

11. The perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the side surface of the through 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.

12. The perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the through-hole has a constricted portion in the center of the thickness direction of the perforated glass substrate for semiconductor packaging, 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.

13. The perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein the diameter of the through hole on the first main surface is 5 μm or more and 200 μm or less, and the diameter of the through hole on the second main surface is 5 μm or more and 200 μm or less.

14. The perforated glass substrate for semiconductor packaging according to any one of claims 1 to 7, wherein at least the inner surface of the through-hole is an etched surface.

15. A glass substrate for semiconductor packaging used in the manufacture of glass substrates having through holes, wherein the glass composition is SiO2 in mol%. ２ 55-75%, Al ２ O ３ 0-20%, B ２ O ３ 0-15%, Li ２ O 0-10%, Na ２ O 5-20%, K ２ A glass substrate for semiconductor packaging, characterized by containing 0-10% O, 0-10% MgO, 0-10% CaO, 0-10% SrO, and 0-10% BaO.

16. A method for manufacturing a perforated glass substrate for semiconductor packaging, comprising: a preparation step of preparing the glass substrate described in claim 15; a laser irradiation step of irradiating the portion of the glass substrate where through 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 a glass substrate having through holes.

17. The method for manufacturing a perforated glass substrate for semiconductor packaging according to claim 16, wherein an alkaline etching solution is used in the etching step.

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