Method for producing glass plate, glass plate, etching device, and device for producing glass plate

Abstract

The present invention addresses the problem of increasing the taper angle of a through hole formed in a glass plate.　A method for producing a glass plate comprises: a modification step S1 for modifying, through exposure to laser light L, a portion Ge of a glass plate G in which a through hole 16 is intended to be formed; and an etching step S2 for forming the through hole 16 in the intended-formation portion Ge by etching the glass plate G after the modification step S1. In the etching step S2, an etching liquid EL is sprayed onto at least one of the first main surface Ga and the second main surface Gb of the vertically oriented glass plate G.

Description

Method for manufacturing a glass plate, glass plate, etching apparatus, and manufacturing apparatus for a glass plate

[0008] ,

[0007] ,

[0001] The present invention relates to a method for manufacturing a glass plate, a glass plate, an etching apparatus, and a manufacturing apparatus for a glass plate.

[0002] In glass substrates used in displays such as tiling displays and borderless displays, and electronic devices such as glass interposers, fine through-holes (TGV: Through Glass Via) are formed for wiring such as through electrodes. In recent years, it has been studied to use a glass plate having such fine through-holes as a core substrate or an interposer for semiconductor packaging.

[0003] As a method for manufacturing a glass plate having this type of through-hole, for example, a modification step of modifying a portion where a through-hole is to be formed in the glass plate by irradiating with a laser beam, and an etching step of forming a through-hole in the portion where the through-hole is to be formed by etching after the modification step (see, for example, Patent Document 1).

[0004] In the etching step, the glass plate is immersed in an etching solution stored in an etching tank. Thereby, etching simultaneously proceeds from both sides of the first main surface and the second main surface of the glass plate, and a through-hole is formed in the portion where the through-hole is to be formed (see paragraph 0031 of the same document).

[0005] The through-hole has a large hole diameter on the first main surface side and the second main surface side, and a small hole diameter at the central portion in the thickness direction of the glass plate. Therefore, the inner surface of the through-hole is formed as an inclined tapered surface. That is, the inner surface of the through-hole has an inclination angle (taper angle) with respect to a direction orthogonal to the plate thickness direction (see paragraph 0039 and FIG. 7 of the same document).

[0006] International Publication No. 2023 / 157625

[0007] When using a glass plate for manufacturing a core substrate or an interposer, in order to improve the number density of through-holes and the wiring density, it is preferable to form through-holes having a large taper angle, that is, a shape close to a straight shape.

[0008] Therefore, the technical problem of the present invention is to increase the taper angle of the through hole formed in the glass plate.

[0009] (1) The present invention is for solving the above problems and is a method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, comprising a modification step of modifying the portion to be formed of the through hole by irradiation with laser light, and an etching step of forming the through hole in the portion to be formed by etching the glass plate after the modification step, wherein in the etching step, an etching solution is sprayed onto at least one of the first main surface and the second main surface of the glass plate in a vertical position.

[0010] With this configuration, in the etching process, since the glass plate is in a vertical position, the etching solution sprayed onto the glass plate flows down along the plate. Therefore, etching is promoted by constantly supplying fresh etching solution to the modified areas formed on the glass plate by the modification process. As etching of the modified areas progresses, recesses are formed in the areas where the modified areas are located. When etching solution is sprayed into these recesses, the etching solution that has entered the recesses is quickly discharged to the outside, making it easier for fresh etching solution to be supplied into the recesses. In the etching process, even after the depth of the recesses increases and through holes are formed, the diameter of the through holes is enlarged by spraying etching solution.

[0011] As described above, by accelerating the replacement of the etching solution, the time required to form through holes can be shortened, and the taper angle of the through holes can be greatly improved.

[0012] Furthermore, because the etching solution is sprayed onto the glass plate, the pressure and impact when the etching solution comes into contact with the glass plate make it easier to remove poorly soluble etching precipitates from inside recesses and through holes, thereby shortening the time required to form through holes and improving the taper angle of the through holes.

[0013] (2) In the method for manufacturing a glass plate described in (1) above, the etching step may involve continuously spraying the etching solution onto the glass plate.

[0014] This configuration allows for a reduction in the time required for the etching process.

[0015] (3) In the method for manufacturing a glass plate described in (1) above, the etching step may involve intermittently spraying the etching solution onto the glass plate.

[0016] With this configuration, while the etching solution is being sprayed, it enters the recesses or through-holes in the glass plate, and when the spraying stops, the etching solution is discharged from the recesses or through-holes. By repeating this operation, the replacement of the etching solution in the recesses or through-holes can be further accelerated.

[0017] (4) In the method for manufacturing a glass plate described in any one of the above items (1) to (3), the etching step may involve spraying the etching solution onto the first main surface and the second main surface of the glass plate.

[0018] With this configuration, etching is performed from both sides of the glass plate, allowing for the formation of through holes from both sides, which shortens the etching process time and increases the hole diameter in the center of the glass plate in the thickness direction. Furthermore, because the glass plate is in a vertical position, it is easier to maintain uniform etching speeds for the first and second main surfaces of the glass plate compared to when the glass plate is laid flat. Specifically, when etching solution is sprayed onto both sides of a glass plate in a flat position, the etching solution is easily discharged from the recesses or through holes on the lower side of the glass plate, facilitating the replacement of the etching solution. On the other hand, the etching solution is difficult to discharge from the recesses or through holes on the upper side of the glass plate, making it difficult to facilitate the replacement of the etching solution. Therefore, by spraying etching solution from both sides of a vertically positioned glass plate, it becomes easier to form through holes with uniform diameters for the first main surface and the second main surface.

[0019] (5) In the method for manufacturing a glass plate described in any one of (1) to (4) above, the etching step is performed with the glass plate housed in a vertical position within an etching apparatus, and the etching apparatus may include a processing unit comprising a holding unit for holding the glass plate in a vertical position and an injection unit for spraying the etching solution onto the glass plate, a storage unit disposed below the processing unit for storing the etching solution sprayed onto the glass plate, a piping unit connecting the storage unit and the injection unit, and a pump for supplying the etching solution stored in the storage unit to the injection unit.

[0020] With this configuration, by placing the storage unit below the processing unit, the installation area of ​​the etching apparatus can be reduced as much as possible. Furthermore, by circulating the etching solution, the etching process can be carried out efficiently.

[0021] (6) In the method for manufacturing a glass plate described in (5) above, the injection unit may be positioned at a distance of 60 mm or more and 110 mm or less from the glass plate.

[0022] With this configuration, the etching solution can be sprayed over the entire glass plate, and the etching solution can be sprayed at an appropriate pressure.

[0023] (7) In the method for manufacturing a glass plate described in (5) or (6) above, the etching apparatus may be equipped with a filter for filtering the etching solution.

[0024] With this configuration, filtering the etching solution with a filter makes it possible to remove poorly soluble etching precipitates, thus preventing a decrease in etching rate and large variations in the diameter of through-holes.

[0025] (8) In the method for manufacturing a glass plate described in any of (5) to (7) above, the glass plate comprises an effective region in which the through hole is formed and an ineffective region in which the through hole is not formed, and the holding portion may hold the ineffective region.

[0026] With this configuration, the non-effective region where through holes are not formed is held by the holding portion, preventing the holding portion from contacting the effective region, and ensuring that etching is performed reliably in the effective region.

[0027] (9) In the method for manufacturing a glass plate described in (8) above, the glass plate is rectangular in shape, the non-effective area includes the edges of the glass plate, and the holding portion may hold at least two side edges and the bottom edge of the glass plate.

[0028] With this configuration, the side and bottom edges of the glass plate are held by the holding parts, thereby preventing the glass plate from shifting position during the etching process.

[0029] (10) In the method for manufacturing a glass plate described in (9) above, the holding portion is provided with a groove that is wider than the thickness of the glass plate, and in the etching step, the etching solution may be sprayed with the side and bottom edges of the glass plate inserted into the groove.

[0030] With this configuration, the glass plate can be easily held by inserting it into the groove of the holding part. As a result, even when etching solution is sprayed onto both sides of the glass plate during the etching process, the glass plate can be held in a stable position.

[0031] (11) In the method for manufacturing a glass plate described in any of (5) to (10) above, the injection unit includes a first injection unit that injects the etching solution onto the first main surface of the glass plate, and a second injection unit that injects the etching solution onto the second main surface of the glass plate, wherein the flow rate of the etching solution injected from the first injection unit is the same as the flow rate of the etching solution injected from the second injection unit.

[0032] With this configuration, by making the injection flow rate of the etching solution from the first injection unit the same as the injection flow rate of the etching solution from the second injection unit, the first and second main surfaces of the glass plate can be etched in a balanced manner, and uniform through-holes can be formed.

[0033] (12) In the method for manufacturing a glass plate described in (12) above, the etching solution may contain at least one of the following: hydrofluoric acid in an amount of 5.0% by mass or more and 20.0% by mass or less; hydrochloric acid in an amount of 3.0% by mass or more and 10.0% by mass or less; sulfuric acid in an amount of 18.0% by mass or more and 28.0% by mass or less; and ammonium hydrofluoric acid in an amount of 1.0% by mass or more and 6.0% by mass or less.

[0034] With this configuration, the etching solution containing sulfuric acid or hydrochloric acid can reduce the amount of poorly soluble fluoride salts precipitated by etching. Furthermore, even if poorly soluble fluoride salts do precipitate, they can be easily dissolved and removed.

[0035] (13) The present invention is for solving the above problems and is an etching apparatus for etching a glass plate having a first main surface, a second main surface, and a modified portion extending between the first main surface and the second main surface, comprising a processing unit for etching the glass plate, wherein the processing unit comprises a holding unit for holding the glass plate in a vertical position and an injection unit for spraying an etching solution onto at least one of the first main surface and the second main surface of the glass plate.

[0036] With this configuration, the glass plate is held in a vertical position by the holding part, and an etching solution is sprayed onto the glass plate from the spraying part, etching the modified part of the glass plate, thereby making the taper angle in the through hole larger than in conventional methods.

[0037] In other words, the etching solution sprayed onto the vertically positioned glass plate flows down the plate. Therefore, by continuously supplying fresh etching solution to the modified area, etching is accelerated.

[0038] As etching of the modified area progresses, recesses are formed in the modified area. When etching solution is sprayed into these recesses, the etching solution that has entered the recesses is quickly discharged out, and new etching solution is easily supplied to the inside of the recesses. Etching increases the depth of the recesses, forming through holes. Subsequently, the diameter of the through holes can be enlarged by spraying etching solution.

[0039] By promoting the replacement of the etching solution as described above, the time required for forming the through hole can be shortened, and the taper angle of the through hole can be greatly improved.

[0040] Further, since the etching solution is sprayed onto the glass plate, it becomes easier to remove the hardly soluble etching precipitate from the inside of the concave portion and the through hole due to the pressure and impact when the etching solution contacts the glass plate, and the time required for forming the through hole can be shortened, and the taper angle of the through hole can be improved.

[0041] (14) In the etching apparatus according to (13) above, a storage portion that is disposed below the processing portion and stores the etching solution sprayed onto the glass plate, a piping portion that connects the storage portion and the spraying portion, and a pump that feeds the etching solution stored in the storage portion to the spraying portion may be provided.

[0042] According to such a configuration, by providing the storage portion below the processing portion, it is possible to make the installation area of the etching apparatus as small as possible.

[0043] (15) The glass plate manufacturing apparatus according to the present invention is for solving the above problems, and is characterized by including the etching apparatus according to (13) or (14) above and a reforming apparatus that forms the reformed portion by irradiating the glass plate with laser light.

[0044] According to such a configuration, by etching the reformed portion formed on the glass plate by the reforming apparatus with the above etching apparatus, a through hole having a large taper angle can be formed in the glass plate.

[0045] (16) The present invention is for solving the above problems, and is a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, wherein the inner surface of the through hole is inclined with respect to the first main surface and the second main surface, and the taper angle formed between the first main surface and the inner surface and the taper angle formed between the second main surface and the inner surface are both 80° or more.

[0046] When the etching time when the etching solution is sprayed onto the glass plate in a vertical posture is the same as the etching time when the glass plate is immersed in the etching solution stored in the etching tank, according to the present invention, a through-hole with a larger taper angle (a through-hole closer to being straight) can be obtained as compared with the method of immersing in the etching solution. In other words, when obtaining a through-hole with the same taper angle, the present invention can etch the glass plate in a shorter time as compared with the method of immersing in the etching solution.

[0047] According to the present invention, the taper angle of the through-hole formed in the glass plate can be increased.

[0048] It is a flowchart showing a method for manufacturing a glass plate. It is a front view of a glass plate in a vertical posture. It is a side view showing a modification step. It is a side view showing an etching step and an etching apparatus. It is a cross-sectional view showing a part of the etching apparatus. It is a cross-sectional view taken along the line VI-VI of FIG. 5. It is a cross-sectional view taken along the line VII-VII of FIG. 5. It is a cross-sectional view of a glass plate showing an etching step. It is a cross-sectional view of a glass plate showing an etching step. It is a cross-sectional view of a glass plate showing an etching step.

[0049] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. FIGS. 1 to 10 show an embodiment of a method and an apparatus for manufacturing a glass plate according to the present invention.

[0050] As shown in FIG. 1, the method for manufacturing a glass plate includes a modification step S1, an etching step S2, and a cleaning step S3. Further, as shown in FIGS. 3 and 4, the apparatus for manufacturing a glass plate includes a laser irradiation apparatus 1 as a modification apparatus for modifying the glass plate G by irradiating the laser light L, an etching apparatus 2 for subjecting the glass plate G to an etching treatment, and a cleaning apparatus (not shown).

[0051] Figure 2 is a front view showing the glass plate in a vertical orientation before the modification process S1 is carried out. This glass plate G is configured as a rectangle with four sides in a front view, but is not limited to this shape. The material of the glass plate G can be soda glass, quartz glass, alkali-free glass, borosilicate glass, aluminosilicate glass, crystallized glass, etc., but when the glass plate G is used as a substrate for electronic equipment, it is preferable that it be quartz glass, alkali-free glass, borosilicate glass, or alkali aluminosilicate glass.

[0052] As shown in Figures 2 and 3, the glass plate G has a first main surface Ga and a second main surface Gb located on the opposite side of the first main surface Ga. The glass plate G also has end faces on all four sides that connect the first main surface Ga and the second main surface Gb. Furthermore, a region Gc in which through holes are formed (hereinafter referred to as the "effective region") is virtually defined in the glass plate G. Within the effective region Gc, wiring such as electrodes will be formed through the through holes during the manufacturing process of displays and electronic devices.

[0053] As shown in Figure 2, the effective area Gc is set inside the four sides of the glass plate G. Therefore, outside the effective area Gc, that is, between the effective area Gc and the four sides of the glass plate G, there is a region Gd in which through holes are not formed (hereinafter referred to as the "non-effective area"). The non-effective area Gd is the outer periphery of the glass plate G and includes the four sides of the glass plate G (top side U, side sides S, and bottom side B). Multiple hypothetical formation areas Ge for forming through holes are set within the effective area Gc of the glass plate G.

[0054] As shown in Figure 3, in the modification step S1, the glass plate G is irradiated with laser light L by the laser irradiation device 1, thereby modifying the area Ge in the glass plate G where through holes are to be formed. As a result, a modified area Gf is formed in the area Ge where holes are to be formed.

[0055] In the modification step S1, laser light L is irradiated from the laser irradiation unit of the laser irradiation device 1 toward the first main surface Ga of the glass plate G. The glass plate G is supported in a horizontal position (flat position) on a support member such as a surface plate (not shown). The laser irradiation unit of the laser irradiation device 1 is configured to be movable relative to the glass plate G, and can irradiate laser light L to a plurality of planned formation areas Ge set in the effective area Gc of the glass plate G. The configuration is not limited to this, however, the support member that supports the glass plate G may be configured to be movable, and the laser light may be irradiated to the planned formation areas Ge of the glass plate G by moving the support member.

[0056] The type and irradiation conditions of the laser light L are not particularly limited, as long as it can form a modified portion Gf in the portion Ge to be formed. In this embodiment, the laser light L is a short-pulse laser light (picosecond laser light, nanosecond laser light, femtosecond laser light).

[0057] The wavelength of the laser light L may be, for example, between 400 nm and 1100 nm.

[0058] The laser irradiation device 1 preferably shapes the laser beam L 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 L into a Bessel beam shape, a modified portion Gf can be formed over the entire thickness direction of the glass plate G with a single laser irradiation, thereby shortening the time required to form the modified portion Gf. In this embodiment, the focal length of the laser beam L is, for example, 0.1 mm or more and 10 mm or less. The spot diameter of the laser beam L is, for example, 0.1 μm or more and 10 μm or less.

[0059] As shown in Figure 3, the modified portion Gf is a linear (e.g., cylindrical) portion extending between the first main surface Ga and the second main surface Gb. The diameter of the modified portion Gf can be adjusted by the spot diameter of the laser beam L, etc.

[0060] The etching apparatus 2 is a shower etching apparatus that sprays etching solution EL onto a vertically positioned glass plate G. As shown in Figures 4 and 5, the etching apparatus 2 comprises an etching tank 3, piping sections 4a and 4b, and a pump 5.

[0061] The etching tank 3 comprises a processing section 6, a storage section 7 located below the processing section 6, and a lid member 8. The processing section 6 is located at the top of the etching tank 3, and the storage section 7 is located at the bottom of the etching tank 3.

[0062] As shown in Figure 4, the processing unit 6 includes holding units 9a and 9b for holding the glass plate G in a vertical position, and spraying units 10a and 10b for spraying etching solution EL onto the glass plate G. The upper part of the processing unit 6 is open upwards. This allows the glass plate G to be inserted into and removed from the etching tank 3 from the upper part of the processing unit 6.

[0063] As shown in Figures 5 to 7, the holding parts 9a and 9b include a first holding part 9a that holds the two side edges S of the glass plate G, and a second holding part 9b that holds the bottom edge B of the glass plate G.

[0064] The first holding portion 9a includes two holding portions so as to hold the two side edges S of the glass plate G. The first holding portion 9a has a groove 11 into which the side edges S of the glass plate G are inserted. The second holding portion 9b is provided below the two first holding portions 9a so as to connect to them. The second holding portion 9b has a groove 11 into which the bottom edge B of the glass plate G is inserted. The groove 11 of the second holding portion 9b is in communication with the groove 11 of the first holding portion 9a. With this configuration, the first holding portion 9a and the second holding portion 9b can simultaneously hold the side edges S and bottom edge B of the glass plate G.

[0065] As shown in Figures 6 and 7, the groove width W of the groove 11 in the first holding portion 9a and the groove width W of the groove 11 in the second holding portion 9b are greater than the thickness T of the glass plate G.

[0066] As shown in Figure 4, the spraying units 10a and 10b include a first spraying unit 10a that sprays etching solution EL onto the first main surface Ga of the glass plate G, and a second spraying unit 10b that sprays etching solution EL onto the second main surface Gb of the glass plate G. Each spraying unit 10a and 10b has nozzles 10a1 and 10b1 at their tips that spray etching solution EL. The nozzles 10a1 and 10b1 spray the etching solution EL at a wide angle, allowing the etching solution EL to be sprayed over the entire effective area Gc on the glass plate G.

[0067] The first injection unit 10a is located at a position away from the first main surface Ga of the glass plate G, which is held in a vertical position, and is facing the first main surface Ga. The second injection unit 10b is located at a position away from the second main surface Gb of the glass plate G, and is facing the second main surface Gb.

[0068] It is preferable that each injection part 10a, 10b is positioned at a distance of 60 mm to 110 mm from the glass plate G. It is preferable that the distance D1 between the first injection part 10a and the first main surface Ga of the glass plate G and the distance D2 between the second injection part 10b and the second main surface Gb of the glass plate G are the same (equal). However, the distances D1 and D2 may be different.

[0069] In this embodiment, it is preferable that the flow rate of the etching solution EL injected from the first injection unit 10a is the same as (equal to) the flow rate of the etching solution EL injected from the second injection unit 10b. In the present invention, the same flow rate is not limited to the case where the ratio Q1 / Q2 of the flow rate Q1 of the etching solution EL injected from the first injection unit 10a and the flow rate Q2 of the etching solution EL injected from the second injection unit 10b is 1, but also includes the case where Q1 / Q2 is 0.9 or more and 1.1 or less.

[0070] The storage section 7 is for storing the etching solution EL sprayed onto the glass plate G. The storage section 7 in this embodiment also has the function of recovering the etching solution EL sprayed onto the glass plate G. The storage section 7 has an outlet 12 for discharging the etching solution EL to the outside, and a filter 13 attached to the side wall of the storage section 7 so as to cover the outlet 12. The outlet 12 is connected to the pump 5 via piping sections 4a and 4b. The filter 13 is for filtering the etching solution EL and collecting foreign matter (slowly soluble precipitates produced by etching) contained in the etching solution EL.

[0071] The cover member 8 is detachably attached to the upper part of the processing unit 6. In the etching process S2, the cover member 8 closes the upper part of the processing unit 6.

[0072] The piping sections 4a and 4b are for connecting the storage section 7 and the injection sections 10a and 10b. The pump 5 is for sending the etching solution EL stored in the storage section 7 to the injection sections 10a and 10b via the piping sections 4a and 4b.

[0073] The piping sections 4a and 4b include a first piping section 4a that connects the discharge port 12 of the storage section 7 to the pump 5, and a second piping section 4b that connects the pump 5 to the injection sections 10a and 10b.

[0074] One end of the first piping section 4a is connected to the discharge port 12 in the storage section 7 of the etching tank 3, and the other end of the first piping section 4a is connected to the pump 5.

[0075] The second piping section 4b includes a first branch pipe 4b1 connected to the first injection section 10a and a second branch pipe 4b2 connected to the second injection section 10b. The first branch pipe 4b1 has an on-off valve (hereinafter referred to as the "first on-off valve") 14a in its middle section. The second branch pipe 4b2 has an on-off valve (hereinafter referred to as the "second on-off valve") 14b in its middle section.

[0076] In etching step S2, first, the glass plate G to be etched is attached to the processing unit 6 of the etching apparatus 2. Specifically, with the lid member 8 removed, the glass plate G is placed in a vertical position and inserted into the processing unit 6 from above the etching tank 3. Furthermore, the lower end of the side edge S of the glass plate G is inserted into the groove 11 of the pair of first holding parts 9a.

[0077] A pair of first holding parts 9a guide the glass plate G downward. As a result, the lower edge B of the glass plate G is inserted into the groove 11 of the second holding part 9b. The glass plate G is supported in a vertical position inside the processing unit 6 by the lower edge B of the non-effective region Gd being held by the second holding part 9b and the pair of side edges S of the non-effective region Gd being held by the first holding part 9a. Here, the inclination angle of the main surfaces Ga and Gb of the glass plate G with respect to the vertical is preferably 15° or less, more preferably 10° or less, and even more preferably 5° or less. If the inclination angle of the main surfaces Ga and Gb of the glass plate G with respect to the vertical is within this range, the difference between the diameter of the through hole in the first main surface Ga and the diameter of the through hole in the second main surface Gb can be reduced. After that, the upper part of the processing unit 6 related to the etching tank 3 is closed by the lid member 8.

[0078] Next, as shown in Figure 4, in etching step S2, the first injection unit 10a sprays the etching solution EL toward the first main surface Ga of the glass plate G, and the second injection unit 10b sprays the etching solution EL toward the second main surface Gb of the glass plate G. In etching step S2, each injection unit 10a and 10b continues to spray the etching solution EL continuously until through holes 16 are formed in the modified portion Gf of the glass plate G.

[0079] In addition to this, each injection unit 10a, 10b can also intermittently inject the etching solution EL. In this case, each injection unit 10a, 10b injects the etching solution EL for a certain period of time and then stops for a certain period of time. In this way, each injection unit 10a, 10b repeats the cycle of injecting the etching solution EL for a certain period of time and then stopping. In this case, the time for injecting the etching solution EL may be, for example, 0.1 seconds or more and 10 seconds or less, and the time for stopping the injection of the etching solution EL may be, for example, 0.1 seconds or more and 10 seconds or less.

[0080] It is preferable to use an aqueous solution EL containing at least one of the following in the etching process S2: hydrofluoric acid in an amount of 5.0% to 20.0% by mass, hydrochloric acid in an amount of 3.0% to 10.0% by mass, sulfuric acid in an amount of 18.0% to 28.0% by mass, and ammonium hydrofluoric acid in an amount of 1.0% to 6.0% by mass.

[0081] The etching solution EL irradiated onto the glass plate G flows downward along the glass plate G and falls downward from the second holding section 9b. The fallen etching solution EL is collected in the storage section 7. The pump 5 supplies the etching solution EL contained in the storage section 7 to the injection sections 10a and 10b through the piping sections 4a and 4b.

[0082] The etching solution EL in the storage section 7 is supplied from the first piping section 4a to the second piping section 4b via the pump 5. The first on-off valve 14a and the second on-off valve 14b of the second piping section 4b are in the open state. The etching solution EL supplied to the second piping section 4b is supplied to the first injection section 10a via the first branch pipe 4b1, and then supplied to the second injection section 10b via the second branch pipe 4b2. By circulating the etching solution EL in this way, the etching process S2 can be performed efficiently.

[0083] The process by which through holes are formed in the glass plate G by etching process S2 will be explained below with reference to Figures 8 to 10.

[0084] The first main surface Ga of the glass plate G is gradually etched as the etching solution EL sprayed from the first spraying section 10a adheres to it and flows. Similarly, the second main surface Gb of the glass plate G is gradually etched as the etching solution EL sprayed from the second spraying section 10b adheres to it and flows. In etching step S2, when the glass plate G is held in a vertical position by the holding sections 9a and 9b, the modified section Gf extends in the horizontal direction. In this case, the portion where the modified section Gf is formed has a higher etching rate compared to other portions, and is therefore etched faster than other portions.

[0085] Therefore, as shown in Figure 8, recesses 15a and 15b are formed by etching in the areas where the modified portion Gf is formed on the first main surface Ga and the second main surface Gb. Hereinafter, the recess 15a formed on the first main surface Ga side will be referred to as the "first recess," and the recess 15b formed on the second main surface Gb side will be referred to as the "second recess."

[0086] The etching solution EL sprayed from the first injection section 10a and the second injection section 10b enters the interior of each recess 15a and 15b and then quickly flows out of each recess 15a and 15b. In detail, each recess 15a and 15b extends horizontally, and the inner surface of each recess 15a and 15b is tapered, widening toward the main surfaces Ga and Gb of the glass plate G. Therefore, the etching solution EL that enters the interior of each recess 15a and 15b quickly flows out of each recess 15a and 15b due to the action of gravity. Then, new etching solution EL enters the interior of each recess 15a and 15b. In this way, the etching solution EL is replaced frequently inside the recesses 15a and 15b, so the time required for the etching process can be shortened as much as possible.

[0087] As the etching process S2 progresses, the depth of each recess 15a and 15b gradually increases along the modified portion Gf. The rate at which the depth of the first recess 15a on the first main surface Ga increases is approximately equal to the rate at which the depth of the second recess 15b on the second main surface Gb increases.

[0088] As the first recess 15a of the first main surface Ga increases in depth, and the second recess 15b of the second main surface Gb increases in depth, the bottom of the first recess 15a and the bottom of the second recess 15b connect, as shown in Figure 9. As a result, a through hole 16 is formed in the area where the modified portion Gf was formed, penetrating between the first main surface Ga and the second main surface Gb.

[0089] As shown in Figure 9, the through hole 16 has a first portion 17a formed by a first recess 15a, a second portion 17b formed by a second recess 15b, and a central portion 17c formed between the first portion 17a and the second portion 17b. The diameter of the first portion 17a at the position of the first main surface Ga (the opening of the through hole 16) is approximately equal to the diameter of the second portion 17b at the position of the second main surface Gb (the opening of the through hole 16). The diameters of the first portion 17a and the second portion 17b are larger than the diameter of the central portion 17c.

[0090] The first portion 17a of the through hole 16 has a tapered shape in which the diameter gradually decreases from the first main surface Ga toward the central portion 17c. Similarly, the second portion 17b of the through hole 16 has a tapered shape in which the diameter gradually decreases from the second main surface Gb toward the central portion 17c.

[0091] As shown in Figures 9 and 10, the diameter of the through-hole 16 gradually increases as the etching process S2 progresses. As shown in Figure 10, the inner surface of the first portion 17a of the through-hole 16 is inclined at an angle θ1 (hereinafter referred to as the "first taper angle") with respect to the first main surface Ga. The inner surface of the second portion 17b of the through-hole 16 is inclined at an angle θ2 (hereinafter referred to as the "second taper angle") with respect to the second main surface Gb.

[0092] The first taper angle θ1 formed by the first main surface Ga and the inner surface of the first portion 17a of the through hole 16 is preferably 80° or more and less than 90°. Similarly, the second taper angle θ2 formed by the second main surface Gb and the inner surface of the second portion 17b of the through hole 16 is preferably 80° or more and less than 90°. The first taper angle θ1 and the second taper angle θ2 are preferably the same. However, they are not limited to this and may be different.

[0093] In Figure 10, the first taper angle θ1 is shown as the angle between the direction Y, which is perpendicular to the thickness direction X of the glass plate G, and the inner surface of the first portion 17a of the through hole 16. The second taper angle θ2 is shown as the angle between the direction Y, which is perpendicular to the thickness direction X of the glass plate G, and the inner surface of the second portion 17b of the through hole 16. The first main surface Ga and the second main surface Gb of the glass plate G are configured to be parallel to the above-mentioned direction Y.

[0094] Once etching process S2 is complete, the glass plate G is removed from the etching apparatus 2. In cleaning process S3, the glass plate G removed from the etching apparatus 2 is placed in a cleaning apparatus. The cleaning apparatus cleans the glass plate G by spraying a cleaning solution (e.g., pure water) through a nozzle.

[0095] According to the manufacturing method and apparatus for the glass plate G of this embodiment described above, in the etching step S2, the etching solution EL is sprayed from the spraying parts 10a and 10b onto the glass plate G, which is housed vertically in the processing section 6 of the etching tank 3, thereby making the taper angles θ1 and θ2 of the through holes 16 as large as possible.

[0096] In other words, in etching step S2, as described above, the etching of the through-holes 16 can be accelerated by improving the exchangeability of the etching solution EL to the recesses 15a, 15b and through-holes 16 of the glass plate G. Specifically, because the etching solution EL is sprayed onto the glass plate G, the pressure and impact when the etching solution EL contacts the glass plate G make it easier to remove poorly soluble etching precipitates from inside the recesses 15a, 15b or through-holes 16, thereby shortening the time required to form the through-holes 16 and allowing the taper angles θ1 and θ2 of the through-holes 16 to be larger than in the conventional method.

[0097] 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.

[0098] In the above embodiment, an etching step S2 was illustrated in which etching solution EL is sprayed onto both the first main surface Ga and the second main surface Gb of the glass plate G by the first spraying unit 10a and the second spraying unit 10b. However, the present invention is not limited to this configuration. That is, in etching step S2, etching solution EL can be sprayed onto at least one of the first main surface Ga and the second main surface Gb.

[0099] For example, through holes 16 may be formed in the glass plate G by bringing the etching solution EL sprayed from the first injection unit 10a into contact only with the first main surface Ga.

[0100] Specifically, by opening the first on-off valve 14a and closing the second on-off valve 14b in the second piping section 4b of the etching apparatus 2, the etching solution EL can be adhered only to the first main surface Ga of the glass plate G. In this case, it is preferable to attach a protective film to the second main surface Gb of the glass plate G. This reliably prevents the etching solution EL from adhering to the second main surface Gb.

[0101] In the above embodiment, an etching apparatus 2 is illustrated in which etching solution EL is supplied to both the first injection section 10a and the second injection section 10b by a single pump 5. However, the present invention is not limited to this configuration. For example, two pumps 5 may be used, with one pump 5 supplying etching solution EL to the first injection section 10a and the other pump 5 supplying etching solution EL to the second injection section 10b.

[0102] In this case, it is preferable to make the amount of etching solution EL sprayed from the first injection unit 10a the same as the amount of etching solution EL sprayed from the second injection unit 10b by adjusting the supply amount of etching solution EL from one pump 5 and the supply amount of etching solution EL from the other pump 5.

[0103] In the above embodiment, the etching apparatus 2 had a first holding part 9a and a second holding part 9b, but the present invention is not limited to this configuration. The holding part of the etching apparatus 2 may be configured to hold only the lower edge B of the vertically positioned glass plate G, or it may be configured to hold only a pair of side edges S.

[0104] In the above embodiment, the etching apparatus 2 was equipped with holding parts 9a and 9b having grooves 11 into which the side edges S and bottom edge B of the glass plate G were inserted, but the present invention is not limited to this configuration. The holding part may be composed of a chuck that holds at least one of the side edges S, bottom edge B, and top edge U of the glass plate G.

[0105] In the above embodiment, both the first retaining portion 9a and the second retaining portion 9b had grooves 11, but the present invention is not limited to this configuration. Only the first retaining portion 9a may have grooves 11, and the second retaining portion 9b may not have grooves 11. In this case, it is possible to prevent the etching solution EL from accumulating in the grooves 11 of the second retaining portion 9b.

[0106] In the above embodiment, the filter 13 was installed so as to cover the discharge port 12 of the storage section 7, but the present invention is not limited to this configuration. The filter 13 may be installed at either position of the piping section 4a or 4b. From the viewpoint of improving workability when replacing the filter, it is preferable to install the filter 13 so as to cover the discharge port 12 of the storage section 7.

[0107] In the above embodiment, an aqueous solution containing hydrofluoric acid was used as the etching solution EL, but the present invention is not limited thereto. Instead of an aqueous solution containing hydrofluoric acid, an aqueous solution containing sodium hydroxide or potassium hydroxide may be used.

[0108] In the above embodiment, the glass plate G was maintained in the same position during the etching process S2, but this is not limited to this. During the etching process S2, a swapping process may be performed to swap the upper edge U and the lower edge B of the glass plate G. When etching is performed by spraying etching solution EL onto a vertically oriented glass plate G, the etching solution EL flows from the upper edge U side to the lower edge B side on the main surfaces Ga and Gb of the glass plate G, so the diameter of the through holes 16 formed in the glass plate G may be uneven between the upper edge U side and the lower edge B side of the glass plate G. By performing a swapping process during the etching process S2, the diameter of the through holes 16 formed in the glass plate G can be made more uniform. The swapping process may be performed multiple times during the etching process S2. In addition, in the swapping process, the upper edge U and the side edge S of the glass plate G may be swapped, as well as the lower edge B and the side edge S.

[0109] Furthermore, in etching step S2, the glass plate G may be rotated along a rotation axis perpendicular to the main surfaces Ga and Gb. This makes the diameter of the through holes 16 formed in the glass plate G more uniform. The rotation speed of the glass plate G is, for example, 10 rpm to 100 rpm.

[0110] The following describes examples of the present invention, but the present invention is not limited to these examples.

[0111] The inventors conducted tests to confirm the effects of the present invention. In these tests, multiple glass plates were prepared as samples, and each glass plate was irradiated with short-pulse laser light to form a modified area. Subsequently, each glass plate was subjected to etching under different conditions. Alkali-free glass (manufactured by Nippon Electric Glass Co., Ltd.: OA-11) was used as the glass plate. The glass plate was square with sides of 50 mm and a thickness of 0.7 mm. Multiple types of aqueous solutions (A to D) having the compositions shown in Table 1 below were used as etching solutions for the etching process.

[0112] Regarding the etching method, two methods were employed: etching the glass plate using the etching apparatus (shower etching apparatus) shown in the above embodiment (spraying), and immersing the glass plate in etching solution stored in an etching tank, as in the conventional method (immersion). In the method of etching the glass plate using the etching apparatus shown in the above embodiment, the etching solution was continuously sprayed onto both main surfaces of the glass plate. The flow rate of the etching solution sprayed from the nozzle was 4 L / min. After the etching process, the taper angle of the through-holes formed in each sample was measured using the following method. First, with the focus on one main surface of the glass plate, the diameter φ1 of the through-hole on that main surface was measured using a digital microscope. Next, with the focus on the center in the thickness direction of the glass plate, the diameter φ2 of the through-hole at the center in the thickness direction of the glass plate was measured using a digital microscope. Then, the thickness T of the glass plate was measured using a micrometer. The taper angle θ of the through-hole was calculated using the formula θ = arctan((φ1 - φ2) / T). In this example, 16 through-holes were formed in one sample, and the average taper angle of the 16 through-holes was calculated.

[0113] The test results are shown in Table 2.

[0114] As shown in Table 2, regardless of the etching solution composition A to D, samples No. 1 to No. 4, in which the etching solution was sprayed onto the glass plate, were able to form through-holes with a taper angle greater than 80°, resulting in a shape close to a straight hole. On the other hand, samples No. 5 to No. 8, in which the glass plate was immersed in the etching solution, had a taper angle smaller than 80°, and were unable to form through-holes close to a straight shape.

[0115] 1 Laser irradiation device (modification device) 2 Etching device 4a First piping section 4b Second piping section 5 Pump 6 Processing section 7 Storage section 9a First holding section 9b Second holding section 10a First injection section 10b Second injection section 11 Groove section 13 Filter 16 Through hole 17a First part (inner surface of through hole) 17b Second part (inner surface of through hole) B Lower edge of glass plate D1 Distance between first injection section and glass plate D2 Distance between second injection section and glass plate EL Etching solution G Glass plate Ga First main surface of glass plate Gb Second main surface of glass plate Gc Effective area Gd Non-effective area Ge Area to be formed Gf Modification section L Laser light S Side edge of glass plate S1 Modification process S2 Etching process T Thickness of glass plate θ1 First taper angle θ² Second taper angle

Claims

1. A method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, comprising: a modification step of modifying the portion to be formed of the through hole by irradiation with laser light; and an etching step of forming the through hole in the portion to be formed by etching the glass plate after the modification step, wherein in the etching step, an etching solution is sprayed onto at least one of the first main surface and the second main surface of the glass plate in a vertical position.

2. The method for manufacturing a glass plate according to claim 1, wherein in the etching step, the etching solution is continuously sprayed onto the glass plate.

3. The method for manufacturing a glass plate according to claim 1, wherein in the etching step, the etching solution is intermittently sprayed onto the glass plate.

4. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein in the etching step, the etching solution is sprayed onto the first main surface and the second main surface of the glass plate.

5. The etching process is performed with the glass plate housed in a vertical position within the etching apparatus, and the etching apparatus comprises a processing unit comprising: a holding unit for holding the glass plate in a vertical position; and an injection unit for spraying the etching solution onto the glass plate; a storage unit disposed below the processing unit for storing the etching solution sprayed onto the glass plate; a piping unit connecting the storage unit and the injection unit; and a pump for supplying the etching solution stored in the storage unit to the injection unit, as described in any one of claims 1 to 3.

6. The method for manufacturing a glass plate according to claim 5, wherein the injection unit is positioned at a distance of 60 mm or more and 110 mm or less from the glass plate.

7. The method for manufacturing a glass plate according to claim 5, wherein the etching apparatus is provided with a filter for filtering the etching solution.

8. The method for manufacturing a glass plate according to claim 5, wherein the glass plate comprises an effective region in which the through-hole is formed and an ineffective region in which the through-hole is not formed, and the holding portion holds the ineffective region.

9. The method for manufacturing a glass plate according to claim 8, wherein the glass plate is rectangular in shape, the non-effective area includes the edges of the glass plate, and the holding portion holds at least two side edges and the bottom edge of the glass plate.

10. The method for manufacturing a glass plate according to claim 9, wherein the holding portion is provided with a groove that is wider than the thickness of the glass plate, and in the etching step, the etching solution is sprayed while the side and bottom edges of the glass plate are inserted into the groove.

11. The method for manufacturing a glass plate according to claim 5, wherein the injection unit includes a first injection unit for injecting the etching solution onto the first main surface of the glass plate and a second injection unit for injecting the etching solution onto the second main surface of the glass plate, and the flow rate of the etching solution injected from the first injection unit is the same as the flow rate of the etching solution injected from the second injection unit.

12. The method for producing a glass plate according to any one of claims 1 to 3, wherein the etching solution comprises at least one of 5.0% to 20.0% by mass of hydrofluoric acid, 3.0% to 10.0% by mass of hydrochloric acid, 18.0% to 28.0% by mass of sulfuric acid, and 1.0% to 6.0% by mass of ammonium hydrofluoric acid.

13. An etching apparatus for etching a glass plate having a first main surface, a second main surface, and a modified portion extending between the first main surface and the second main surface, comprising a processing unit for etching the glass plate, wherein the processing unit comprises a holding unit for holding the glass plate in a vertical position and an injection unit for spraying an etching solution onto at least one of the first main surface and the second main surface of the glass plate.

14. The etching apparatus according to claim 13, comprising: a storage unit located below the processing unit for storing the etching solution sprayed onto the glass plate; a piping unit connecting the storage unit and the spraying unit; and a pump for supplying the etching solution stored in the storage unit to the spraying unit.

15. A glass plate manufacturing apparatus comprising an etching apparatus according to claim 13 or 14, and a modification apparatus for forming the modified portion by irradiating the glass plate with laser light.

16. A glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, wherein the inner surface of the through hole is inclined with respect to the first main surface and the second main surface, and the taper angle between the first main surface and the inner surface, and the taper angle between the second main surface and the inner surface are both 80° or more.

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