Glass plate and method for manufacturing same
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- NIPPON ELECTRIC GLASS CO LTD
- Filing Date
- 2026-01-20
- Publication Date
- 2026-08-06
Smart Images
Figure JP2026001592_06082026_PF_FP_ABST
Abstract
Description
Glass plate and method for manufacturing the same
[0001] The present invention relates to a method for manufacturing a glass plate having through-holes and a glass plate.
[0002] Conventionally, as substrates such as core substrates and interposer substrates used in electronic components, the development of glass plates having fine through-holes for wiring has been in progress. Further, a glass plate having through-holes can also be used as a filter used in inspection devices and analytical devices.
[0003] As a method for manufacturing a glass plate having through-holes, for example, a method of forming a modified portion by irradiating a laser beam to a position where a through-hole is to be formed in a glass plate and removing the formed modified portion by etching to form a through-hole is known (for example, Patent Document 1 and Patent Document 2). In these methods, the diameter of the through-hole is not uniform in the thickness direction of the glass plate, and a constricted portion having a small hole diameter may be locally formed.
[0004] Japanese Patent No. 7213852, Japanese Unexamined Patent Application Publication No. 2023-179101
[0005] When forming a through-electrode on a glass plate or using the glass plate as a filter, the performance as a through-electrode or a filter is affected by the hole diameter (hereinafter referred to as the minimum hole diameter) at the location where the hole diameter is the smallest in the plate thickness direction of the glass plate. Therefore, in the manufacturing process of a glass plate having through-holes, it is necessary to measure and manage the minimum hole diameter of the glass plate. However, in the method described in Patent Document 1, since etching progresses uniformly from both main surfaces of the glass plate in the modified portion, a constricted portion occurs at the center in the plate thickness direction of the glass plate, and the diameter in the constricted portion becomes the minimum hole diameter. Since it becomes difficult to measure the diameter of the constricted portion as the constricted portion is farther from both main surfaces, it is difficult to manage the minimum hole diameter of the glass plate by the method described in Patent Document 1.
[0006] Furthermore, in the method described in Patent Document 2, a protective film is attached to the glass plate throughout the entire etching process, so etching proceeds only from one main surface side of the glass plate, forming an isosceles trapezoidal through-hole in cross-section. In this case, the position of the constriction coincides with the position of the main surface of the glass plate, so the minimum hole diameter can be easily measured. However, when the position of the constriction coincides with the position of the main surface, the constriction becomes acute, which can easily lead to stress concentration and the risk of the glass plate breaking.
[0007] The object of the present invention is to provide a method for manufacturing glass plates and a glass plate that can increase the productivity of glass plates having through holes and prevent glass plates from being damaged.
[0008] A method for manufacturing a glass plate and various forms of the glass plate that solve the above problems will be described below.
[0009] A method for manufacturing a glass plate according to Embodiment 1 of the present invention is a method for manufacturing a glass plate having through holes, and is characterized by comprising: a glass plate preparation step of preparing a glass plate having a first main surface and a second main surface which is the opposite surface of the first main surface; a laser light irradiation step of irradiating the first main surface of the glass plate with laser light at a position where through holes are to be formed to form a modified portion; a film application step of applying a protective film to the second main surface of the glass plate before or after the laser light irradiation step; a single-sided etching step of applying an etching treatment to the glass plate with the protective film applied to the second main surface of the glass plate; a film peeling step of peeling the protective film from the second main surface of the glass plate; and a double-sided etching step of applying an etching treatment to the glass plate with the protective film peeled from the second main surface of the glass plate to form through holes in the glass plate. In the glass plate manufacturing method according to Embodiment 1, a recess is formed in a single-sided etching step such that the diameter increases from the second main surface side to the first main surface side of the glass plate. Then, in a double-sided etching step, the portion between the bottom of the recess and the second main surface of the glass plate is etched from both sides. As a result, in the resulting glass plate, the diameter of the through-holes in the first main surface is larger than the diameter of the through-holes in the second main surface, and in the thickness direction of the glass plate, a locally narrowed portion with a small hole diameter or a straight portion with a uniform hole diameter is formed between the intermediate surface between the first and second main surfaces and the second main surface. In this way, in the thickness direction of the glass plate, the position of the narrowed portion approaches the second main surface, or a straight portion is formed, making it easier to measure the minimum hole diameter of the through-holes. Furthermore, in the thickness direction of the glass plate, if the constricted portion is located inside the first main surface and the second main surface, or if a straight portion is formed, it is possible to prevent the formation of sharp angles on the glass plate at the points where the through hole intersects with the first main surface and at the points where the through hole intersects with the second main surface, thereby preventing the glass plate from breaking.
[0010] In the glass plate manufacturing method according to Embodiment 2, it is preferable that the etching rate in the double-sided etching process of Embodiment 1 is lower than the etching rate in the single-sided etching process. In this case, when the through-hole portion formed in the single-sided etching process is designated as the first through-hole portion, and the through-hole portion formed in the double-sided etching process is designated as the second through-hole portion, the second through-hole portion can be made to be close to a straight shape, or can be made to be a straight shape. Furthermore, when the second through-hole portion is a straight shape, the diameter of the through-hole on the second main surface becomes the minimum hole diameter, so the minimum hole diameter can be controlled simply by measuring the diameter of the through-hole on the second main surface.
[0011] In the glass plate manufacturing method according to Embodiment 3, it is preferable to etch the glass plate using an etching solution containing hydrofluoric acid aqueous solution in the single-sided etching step of Embodiment 1 or Embodiment 2, and to etch the glass plate using an etching solution containing sodium hydroxide aqueous solution or potassium hydroxide aqueous solution in the double-sided etching step. In this case, it becomes easier to make the etching rate in the double-sided etching step lower than the etching rate in the single-sided etching step.
[0012] In the glass plate manufacturing method according to Embodiment 4, in any one embodiment from Embodiments 1 to 3, the protective film comprises a base material and an adhesive layer provided on one main surface of the base material, wherein the base material is made of a polyolefin resin and the adhesive layer is made of an acrylic resin. In this case, the second main surface of the glass plate can be protected more reliably in the single-sided etching process.
[0013] In the glass plate manufacturing method according to Embodiment 5, in the single-sided etching step of any one of Embodiments 1 to 4, it is preferable to apply an etching treatment to the glass plate to form a recess in the modified portion on the first main surface side of the glass plate, and in the film peeling step, to peel the protective film from the second main surface of the glass plate before the bottom of the recess on the glass plate reaches the second main surface. In this case, the total time required for the single-sided etching step and the double-sided etching step can be shortened.
[0014] In the glass plate manufacturing method according to Embodiment 6, it is preferable that the thickness of the glass plate is 200 μm or less in any one embodiment from Embodiment 1 to Embodiment 5. In this case, the effects of the present invention can be exhibited even more effectively.
[0015] A glass plate according to embodiment 7 of the present invention is a glass plate having a first main surface and a second main surface which is the opposite surface of the first main surface, and a through hole provided so as to extend from the first main surface to the second main surface, wherein the diameter of the through hole on the first main surface of the glass plate is larger than the diameter of the through hole on the second main surface, the first taper angle θ1 which is the taper angle of the inner surface of the through hole on the first main surface is 90° or more, and the second taper angle θ2 which is the taper angle of the inner surface of the through hole on the second main surface is 90° or more. In the glass plate according to embodiment 7, it is possible to prevent the formation of sharp angles on the glass plate at the positions where the through hole and the first main surface intersect, and at the positions where the through hole and the second main surface intersect, thereby preventing the glass plate from breaking.
[0016] In the glass plate according to embodiment 8, in embodiment 7, the through hole of the glass plate may have a hole diameter expansion portion in which the diameter of the through hole increases from the second main surface side to the first main surface side of the glass plate. In this case, the first taper angle θ1 can be made to be larger than 90° more reliably.
[0017] In the glass plate according to embodiment 9, in embodiment 8, the hole diameter enlargement portion in the through hole of the glass plate may be provided on the first main surface side of the center in the thickness direction of the glass plate. In this case, the diameter of the through hole on the first main surface can be made smaller, and the through hole can be formed at a higher density.
[0018] In the glass plate according to embodiment 10, in any one embodiment from embodiment 7 to embodiment 9, the first taper angle θ1 may be larger than the second taper angle θ2. In this case, the diameter of the through hole in the first main surface is larger than the diameter of the through hole in the second main surface, and furthermore, since the first taper angle θ1 is larger than the second taper angle θ2, it becomes easier to form the hole diameter enlargement portion on the first main surface side of the center in the thickness direction of the glass plate. As a result, the diameter of the through hole in the first main surface can be made smaller, and through holes can be formed at a higher density.
[0019] In the glass plate according to embodiment 11, in any one embodiment from embodiment 7 to embodiment 10, the shape of the through hole in a cross section along the thickness direction of the glass plate may have a locally narrowed portion with a smaller hole diameter, and the narrowed portion may be located on the second main surface side of the center in the thickness direction of the glass plate. In this case, when a conductive material is filled into the through hole to provide a through electrode, the through electrode becomes less likely to detach from the through hole.
[0020] In the glass plate according to embodiment 12, in any one embodiment from embodiment 7 to embodiment 10, the shape of the through hole may have a straight section with a uniform hole diameter in a cross section along the thickness direction of the glass plate. In this case, the presence of a straight section in the through hole makes it less likely for the hole diameter to become narrower. Furthermore, if the straight section reaches the first main surface or the second main surface, the minimum hole diameter can be controlled simply by measuring the hole diameter of the straight section.
[0021] In the glass plate according to embodiment 13, it is preferable that the first main surface and the second main surface of the glass plate are etched surfaces in any one embodiment from embodiment 7 to embodiment 12. When the first main surface and the second main surface of the glass plate are etched surfaces, cracks are removed, and the strength of the glass plate can be further increased.
[0022] According to the present invention, it is possible to provide a method for manufacturing glass plates and a glass plate that can increase the productivity of glass plates having through holes and prevent the glass plates from breaking.
[0023] Figures 1(a) to 1(e) are schematic cross-sectional views illustrating a method for manufacturing a glass plate according to one embodiment of the present invention. Figure 2 is a schematic plan view showing a glass plate according to one embodiment of the present invention. Figure 3 is a schematic cross-sectional view of the portion along line A-A in Figure 2. Figure 4 is a photograph showing a through-hole in a glass plate manufactured in the embodiment. Figure 5 is a graph for confirming the change in hole diameter along the thickness direction in a through-hole in a glass plate manufactured in the embodiment.
[0024] Preferred embodiments are described below. However, the following embodiments are merely illustrative, and the present invention is not limited to these embodiments. In each drawing, components having substantially the same function may be referred to by the same reference numerals.
[0025] [Method for Manufacturing Glass Plates] The method for manufacturing glass plates according to the present invention is a method for manufacturing glass plates having through holes. The method for manufacturing glass plates according to the present invention comprises a glass plate preparation step, a laser light irradiation step, a film application step, a single-sided etching step, a film peeling step, and a double-sided etching step. The details of each step of the method for manufacturing glass plates according to one embodiment of the present invention will be described below with reference to Figures 1(a) to (e).
[0026] (Glass plate preparation process) In the glass plate preparation process, a glass plate 1 is prepared as shown in Figure 1(a). As the glass plate 1, the original glass plate before the through hole is formed is prepared. As the glass plate 1, a glass plate 1 is prepared having a first main surface 1a and a second main surface 1b which is the opposite surface of the first main surface 1a.
[0027] The glass plate 1 can be prepared by forming the glass material using known forming methods such as the down-draw method, float method, or roll-out method. Examples of down-draw methods include the overflow down-draw method and the slot down-draw method. Among these, the overflow down-draw method is preferred for forming the glass material. In the overflow down-draw method, the surface that will become the surface of the glass plate is formed in a free surface state, and thus becomes a forged surface. Therefore, the smoothness of the first main surface 1a and the second main surface 1b of the resulting glass plate 1 can be further improved.
[0028] Examples of materials for the glass plate 1 include alkali-free glass, soda-lime glass, quartz glass, borosilicate glass, aluminosilicate glass, and crystallized glass.
[0029] The thickness of the glass plate 1 is not particularly limited, but is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. Alternatively, the thickness of the glass plate 1 is preferably 200 μm or less, more preferably 180 μm or less, and even more preferably 150 μm or less. The thickness of the glass plate 1 may be achieved by performing a slimming or other treatment on the glass plate formed by the molding method described above.
[0030] (Laser Irradiation Process) In the laser irradiation process, as shown in Figure 1(b), laser light X is irradiated onto the planned through-hole formation position 2 on the first main surface 1a of the glass plate 1 to form a modified portion 3. In the modified portion 3, the etching rate can be faster than in the portion not irradiated by laser light X. Therefore, through-holes can be formed at the position where the modified portion 3 is provided by the single-sided etching process and double-sided etching process described later. In the modified portion 3, at least one of the properties among stress, density, and optical properties has changed, or minute cracks or voids have been formed. On the other hand, in the unmodified portion (the part excluding the modified portion 3), at least one of the properties among stress, density, and optical properties has not changed, or only a substantially negligible change has occurred. Furthermore, no minute cracks or voids have been formed in the unmodified portion.
[0031] The type of laser light X and irradiation conditions are not particularly limited, as long as a modified portion 3 can be formed at the planned through-hole formation position 2. As the laser light X, for example, pulsed laser light with a pulse width of picoseconds to femtoseconds can be used. The pulse width is preferably, for example, 50 fs or more and 100 ps or less. The energy per pulse of the laser light X is preferably 80 μJ or less. The energy per pulse of the laser light X is preferably 35 μJ or more, more preferably 40 μJ or more, even more preferably 45 μJ or more, even more preferably 50 μJ or more, particularly preferably 55 μJ or more, preferably 80 μJ or less, more preferably 75 μJ or less, even more preferably 70 μJ or less, even more preferably 65 μJ or less, particularly preferably 60 μJ or less. The wavelength of the laser light X is preferably 400 nm or more, more preferably 500 nm or more. The wavelength of the laser light X is preferably 1050 nm or less, more preferably 850 nm or less. The laser beam X may be irradiated after fixing the glass plate 1 to a support substrate or the like.
[0032] Preferably, the laser beam X is formed into a Bessel beam by an optical system including an axicon lens, etc., provided in an irradiation device (not shown). This allows the modified portion 3 to be formed over the entire thickness of the glass plate 1 with just one pulse of laser irradiation, thus reducing the time required to form the modified portion 3. In this embodiment, the focal length of the laser beam X is, for example, 0.1 mm or more and 10 mm or less. The spot diameter of the laser beam X is, for example, 0.1 μm or more and 10 μm or less. The size of the modified portion 3 in plan view can be adjusted by the irradiation conditions of the laser beam X, for example, by changing the spot diameter, focal position, etc.
[0033] In this embodiment, the modification section 3 is provided so as to extend from the first main surface 1a to the second main surface 1b of the glass plate 1. However, the modification section 3 does not necessarily have to extend to the second main surface 1b of the glass plate 1. The ratio of the depth d1 of the modification section 3 to the distance L1 from the first main surface 1a to the second main surface 1b of the glass plate 1 (d1 / L1) is preferably 0.5 or more, more preferably 0.6 or more. The ratio of the depth d1 to the distance L1 (d1 / L1) is preferably 1 or less, more preferably 0.9 or less.
[0034] (Film application process) In the film application process, as shown in Figure 1(c), a protective film 4 is applied to the second main surface 1b of the glass plate 1. In this embodiment, the film application process is performed after the laser irradiation process. From the viewpoint of more reliably preventing the protective film 4 from deteriorating due to the laser irradiation process, it is preferable to perform the film application process after the laser irradiation process. However, in the present invention, the film application process may be performed before the laser irradiation process. From the viewpoint of improving workability when performing the laser irradiation process, it is preferable to perform the film application process before the laser irradiation process. For example, if the glass plate 1 is thin and flexible, applying the protective film 4 to the glass plate 1 provides the glass plate 1 with appropriate rigidity, improving workability when moving the glass plate 1, etc.
[0035] As the protective film 4, for example, an adhesive film can be used, which comprises a base material 5 and an adhesive layer 6 provided on the main surface 5a of one side of the base material.
[0036] As the material for the base material 5, for example, polyolefin resins such as polyethylene or polypropylene, polyester resins such as polyethylene terephthalate (PET), polyimide, aromatic polyether ketones such as polyether ether ketone (PEEK), polyvinyl chloride, etc. can be used. In this case, the chemical resistance and flexibility of the base material 5 can be further improved.
[0037] Acrylic adhesives, silicone adhesives, polyolefin adhesives, ethylene vinyl acetate adhesives, etc., can be used as the material for the adhesive layer 6. In this case, the chemical resistance and flexibility of the adhesive layer 6 can be further improved.
[0038] The adhesive layer 6 is preferably composed of a resin whose adhesive strength changes between the time of fixing and the time of peeling due to a predetermined treatment. Examples of resins that constitute such an adhesive layer 6 include ultraviolet-curable resins that harden when exposed to ultraviolet light, and thermosetting resins that harden when heated. Examples of such ultraviolet-curable resins or thermosetting resins include acrylic resins and styrene resins. The protective film 4 may be a self-adhesive film that can be peeled off without any predetermined treatment.
[0039] In the protective film 4, it is preferable that the base material 5 is made of a polyolefin resin and the adhesive layer 6 is made of an acrylic resin. In this case, the second main surface 1b of the glass plate 1 can be protected more reliably in the single-sided etching process described later.
[0040] The adhesive strength of the protective film 4 when fixed is preferably stronger than the adhesive strength when peeled off. The adhesive strength of the protective film 4 when fixed is preferably 2 N / 20 mm or more, more preferably 5 N / 20 mm or more. The adhesive strength of the protective film 4 when fixed is preferably 40 N / 20 mm or less, more preferably 20 N / 20 mm or less. The adhesive strength of the protective film 4 when peeled off is preferably 0.01 N / 20 mm or more, more preferably 0.05 N / 20 mm or more. The adhesive strength of the protective film 4 when peeled off is preferably 1 N / 20 mm or less, more preferably 0.5 N / 20 mm or less. The adhesive strength can be measured, for example, in accordance with JIS Z 0237:2022.
[0041] The thickness of the protective film 4 is, for example, 60 μm or more and 200 μm or less. In this case, the rigidity and flexibility of the protective film 4 can be improved in a more balanced manner. The thickness of the base material 5 is, for example, 50 μm or more and 150 μm or less. The thickness of the adhesive layer 6 is, for example, 10 μm or more and 30 μm or less.
[0042] The protective film 4 is preferably larger than the glass plate 1 in a plan view. In this case, the handling property of the glass plate 1 (and the protective film 4) can be further improved. Also, even when the glass plate 1 is thin, the glass plate 1 can be processed more simply and reliably.
[0043] (One-sided etching step) In the one-sided etching step, an etching treatment is performed on the glass plate 1 in a state where the protective film 4 is attached to the second main surface 1b of the glass plate 1. The etching treatment can be performed, for example, by immersing the glass plate 1 in an etching solution and etching the modified portion 3 of the glass plate 1. In the one-sided etching step, by etching the modified portion 3 of the glass plate 1, a concave portion 7 can be formed on the glass plate 1 as shown in FIG. 1(d).
[0044] In the one-sided etching step, the etching treatment of the modified portion 3 of the glass plate 1 proceeds from the first main surface 1a side where the protective film 4 is not attached. Therefore, the concave portion 7 is etched for a longer time at a location closer to the first main surface 1a. Also, compared with the location of the bottom portion 7a of the concave portion 7 closer to the first main surface 1a, it is difficult for the etching solution to be exchanged and for hardly soluble by-products to be discharged. Therefore, the concave portion 7 is formed so that its diameter increases from the second main surface 1b side to the first main surface 1a side of the glass plate 1.
[0045] In the one-sided etching step, the etching treatment is terminated before the bottom portion 7a of the concave portion 7 formed on the glass plate 1 reaches the second main surface 1b. At this time, the processing conditions of the etching treatment are adjusted so that the etching treatment is terminated before the bottom portion 7a of the concave portion 7 formed on the glass plate 1 reaches the second main surface 1b.
[0046] In the single-sided etching process, it is preferable that the etching solution contains an acid, and it is more preferable that the etching solution contains an aqueous hydrofluoric acid solution. In this case, the etching solution may be a single acid of hydrofluoric acid or a mixed acid of hydrofluoric acid and other acids such as hydrochloric acid, nitric acid, sulfuric acid, phosphoric acid, and acetic acid. The other acids may be inorganic acids or organic acids. Further, the etching solution may contain a surfactant.
[0047] In the single-sided etching process, when the etching solution is an aqueous solution, the concentration of hydrofluoric acid in the etching solution is preferably 0.5 mol / L or more, and more preferably 1.0 mol / L or more. The concentration of hydrofluoric acid in the etching solution is preferably 4.0 mol / L or less, and more preferably 3.0 mol / L or less. When the etching solution contains other acids, the concentration of the other acids in the etching solution can be, for example, 0.1 mol / L or more and 1.0 mol / L or less.
[0048] In the single-sided etching process, the processing temperature of the etching treatment is preferably 5°C or more, and more preferably 10°C or more. The processing temperature is preferably 40°C or less, and more preferably 30°C or less. Further, the processing time of the etching treatment is preferably 1 minute or more, more preferably 2 minutes or more, and even more preferably 3 minutes or more. The processing time is preferably 20 minutes or less, more preferably 15 minutes or less, and even more preferably 10 minutes or less.
[0049] The etching rate v1 in the single-sided etching process is preferably 0.1 μm / min or more, and more preferably 0.2 μm / min or more. The etching rate v1 is preferably 2 μm / min or less, and more preferably 1 μm / min or less.
[0050] In the single-sided etching process, the glass plate 1 may be immersed in the etching solution for etching treatment, or the etching solution may be applied or sprayed on the first main surface 1a side of the glass plate 1 for etching treatment.
[0051] The ratio (d2 / L1) of the depth d2 of the recess 7 formed in the glass plate 1 to the distance L1 from the first main surface 1a to the second main surface 1b of the glass plate 1 is preferably 0.1 or more, more preferably 0.2 or more. The ratio (d2 / L1) of the depth d2 to the distance L1 is preferably 0.4 or less, more preferably 0.3 or less. The depth d2 of the recess 7 formed in the glass plate 1 corresponds to the distance from the first main surface 1a of the glass plate 1 to the bottom 7a of the recess 7.
[0052] (Film peeling process) In the film peeling process, the protective film 4 is peeled off from the second main surface 1b of the glass plate 1. In particular, in the film peeling process, the protective film 4 is peeled off from the second main surface 1b of the glass plate 1 before the bottom 7a of the recess 7 of the glass plate 1 reaches the second main surface 1b.
[0053] When peeling the protective film 4 from the second main surface 1b of the glass plate 1, the adhesive strength of the protective film 4 may be reduced before peeling it off. For example, if the adhesive layer 6 constituting the protective film 4 is made of an ultraviolet-curable resin, the adhesive layer 6 may be cured by irradiating it with ultraviolet light, thereby reducing the adhesive strength of the protective film 4 (adhesive layer 6). Alternatively, if the adhesive layer 6 constituting the protective film 4 is made of a thermosetting resin, the adhesive layer 6 may be cured by heating it with a heater or the like, thereby reducing the adhesive strength of the protective film 4 (adhesive layer 6).
[0054] Furthermore, in order to facilitate the removal of the protective film 4, the protective film 4 may be provided so as to be larger than the glass plate 1 in a plan view. In this case, the excess portion of the protective film 4 can be supported and removed in a plan view, which further reduces damage to the glass plate 1 and allows for smoother removal of the protective film 4.
[0055] (Double-sided etching process) In the double-sided etching process, with the protective film 4 peeled off from the second main surface 1b of the glass plate 1, the glass plate 1 is subjected to etching to form through holes 12 as shown in Figure 1(e). This makes it possible to obtain a glass plate 11 having through holes 12.
[0056] The etching process can be carried out, for example, by immersing the glass plate 1 in an etching solution after peeling off the protective film 4 from the second main surface 1b of the glass plate 1, and etching the portion between the bottom 7a of the recess 7 of the glass plate 1 and the second main surface 1b from both sides.
[0057] In the double-sided etching process, the protective film 4 is peeled off from the second main surface 1b of the glass plate 1, and the etching process is performed from both sides of the glass plate 1. This allows the etching process to be completed in a shorter time than the single-sided etching process. Therefore, the manufacturing method of this embodiment can increase the productivity of glass plates 11 having through holes 12. Furthermore, in this embodiment, as described above, the single-sided etching process is completed before the bottom 7a of the recess 7 formed in the glass plate 1 reaches the second main surface 1b, and then the film peeling process and the double-sided etching process are performed. This makes it possible to shorten the total processing time of the single-sided etching process and the double-sided etching process.
[0058] The etching rate v2 in the double-sided etching process is preferably 0.01 μm / min or more, more preferably 0.02 μm / min or more. The etching rate v2 is preferably 0.05 μm / min or less, more preferably 0.04 μm / min or less.
[0059] The etching rate v2 in the double-sided etching process is preferably lower than the etching rate v1 in the single-sided etching process. The ratio of the etching rate v1 in the single-sided etching process to the etching rate v2 in the double-sided etching process (v1 / v2) is preferably 2 or more, more preferably 5 or more. The ratio of the etching rate v1 to the etching rate v2 (v1 / v2) is preferably 20 or less, more preferably 15 or less.
[0060] By making the etching rate v2 in the double-sided etching process lower than the etching rate v1 in the single-sided etching process, the second through-hole portion 12b between the first through-hole portion 12a corresponding to the recess 7 of the glass plate 1 and the second main surface 1b can be made to be closer to a straight shape, or even a straight shape (straight portion). In this case, not only the first through-hole portion 12a corresponding to the recess 7 of the glass plate 1 formed in the single-sided etching process, but also the second through-hole portion 12b, is less likely to form a constricted portion in the cross-sectional shape along the thickness direction of the glass plate 1.
[0061] In the double-sided etching process, it is preferable that the etching solution contains an alkali, and more preferably that the etching solution contains an aqueous solution of sodium hydroxide or an aqueous solution of potassium hydroxide.
[0062] By using an etching solution containing hydrofluoric acid aqueous solution in the single-sided etching process and an etching solution containing sodium hydroxide aqueous solution or potassium hydroxide aqueous solution in the double-sided etching process, the etching rate v2 in the double-sided etching process can be made lower than the etching rate v1 in the single-sided etching process. Note that etching rates v1 and v2 may be adjusted by other etching treatment conditions such as the concentration and temperature of the etching solution. For example, if the same type of etching solution is used in both the single-sided and double-sided etching processes, the etching rate v2 can be made lower than the etching rate v1 by using an etching solution with a lower concentration or lower temperature in the double-sided etching process than in the single-sided etching process.
[0063] In the double-sided etching process, when the etching solution is an aqueous solution, the concentration of sodium hydroxide or potassium hydroxide contained in the etching solution is preferably 10 mol / L or more, more preferably 15 mol / L or more. The concentration of sodium hydroxide or potassium hydroxide is preferably 25 mol / L or less, more preferably 19 mol / L or less.
[0064] In the double-sided etching process, the etching temperature is preferably 70°C or higher, more preferably 80°C or higher. The etching temperature is preferably 130°C or lower, more preferably 110°C or lower. The etching time is preferably 1 hour or more, more preferably 2 hours or more. The etching time is preferably 7 hours or less, more preferably 6 hours or less.
[0065] In the double-sided etching process, the glass plate 1 may be immersed in an etching solution to perform the etching process, or the etching solution may be applied or sprayed onto both the first main surface 1a and the second main surface 1b of the glass plate 1 to perform the etching process.
[0066] The manufacturing method of this embodiment may further include a cleaning step to clean the glass plate 11 after the double-sided etching step, and an inspection step to confirm the structure of the formed through-holes 12.
[0067] In the manufacturing method of this embodiment, in the single-sided etching process, a recess 7 is formed such that its diameter increases from the second main surface 1b side to the first main surface 1a side of the glass plate 1. Then, in the double-sided etching process, the portion between the bottom 7a of the recess 7 and the second main surface 1b of the glass plate 1 is etched from both sides. As a result, in the resulting glass plate 11, the hole diameter D1 of the through hole 12 in the first main surface 11a is larger than the hole diameter D2 of the through hole 12 in the second main surface 11b. Furthermore, in the thickness direction of the glass plate 11, a locally narrowed portion with a smaller hole diameter or a straight portion with a uniform hole diameter is formed between the intermediate surface of the first main surface 11a and the second main surface 11b and the second main surface 11b, that is, in the second through hole portion 12b. In this way, in the thickness direction of the glass plate 11, the position of the constricted portion approaches the second main surface 11b, and a straight portion is formed in the second through-hole portion 12b, making it easier to measure the minimum hole diameter. Furthermore, in the thickness direction of the glass plate 11, the position of the constricted portion approaches the second main surface 11b, and a straight portion is formed in the second through-hole portion 12b, which prevents the formation of sharp angles on the glass plate 11 at the intersection of the through-hole 12 and the first main surface 11a, and at the intersection of the through-hole 12 and the second main surface 11b, thus preventing the glass plate 11 from being damaged. In addition, in the manufacturing method of the glass plate 11 of this embodiment, the protective film 4 only needs to be attached to the second main surface 1b of the glass plate 1 during the single-sided etching process, and in particular, the double-sided etching process is not performed with the protective film 4 attached, thus shortening the time required to manufacture the glass plate 11. Accordingly, the manufacturing method of this embodiment can increase the productivity of the glass plate 11.
[0068] [Glass Plate] Figure 2 is a schematic plan view showing a glass plate according to one embodiment of the present invention. Figure 3 is a schematic cross-sectional view of the portion along line A-A in Figure 2.
[0069] As shown in Figure 2, the glass plate 11 has multiple through holes 12. However, the glass plate 11 may have only one through hole 12, and the number of through holes 12 is not particularly limited. The number of through holes 12 can be, for example, one or more and up to 25 million.
[0070] As shown in Figure 3, the glass plate 11 has a first main surface 11a and a second main surface 11b which is the opposite surface to the first main surface 11a. The glass plate 11 is provided with a through hole 12 that extends from the first main surface 11a to the second main surface 11b.
[0071] The diameter D1 of the through-hole 12 in the first main surface 11a of the glass plate 11 is larger than the diameter D2 of the through-hole 12 in the second main surface 11b. Such through-holes 12 in the glass plate 11 can be formed, for example, according to the glass plate 11 manufacturing method described above. Furthermore, since the glass plate 11 manufacturing method described above includes a double-sided etching process, the first main surface 11a, the second main surface 11b, and the inner surface of the through-hole 12 in the resulting glass plate 11 become etched surfaces. In this case, even if cracks are formed in the glass plate 1, the cracks are removed by etching, thereby further increasing the strength of the resulting glass plate 11.
[0072] The ratio of the hole diameter D1 of the through hole 12 to the hole diameter D2 (D1 / D2) is preferably 1 or more, more preferably 1.2 or more, and even more preferably 1.3 or more. The ratio of the hole diameter D1 to the hole diameter D2 (D1 / D2) is preferably 2.5 or less, more preferably 2 or less, and even more preferably 1.6 or less. The hole diameter D1 of the through hole 12 can be, for example, 8 μm or more and 20 μm or less. The hole diameter D2 of the through hole 12 can be, for example, 5 μm or more and 17 μm or less.
[0073] The difference between the hole diameter D1 and hole diameter D2 of the through hole 12 (D1-D2) is preferably 1 μm or more, more preferably 2 μm or more, more preferably 3 μm or more, even more preferably more than 3 μm, and particularly preferably 3.5 μm or more. The difference between the hole diameter D1 and hole diameter D2 (D1-D2) is preferably 10 μm or less, more preferably 8 μm or less, even more preferably 6 μm or less, and particularly preferably 4 μm or less.
[0074] On the first main surface 11a of the glass plate 11, the pitch of the through holes 12 can be, for example, 10 μm or more and 1 mm or less. Similarly, on the second main surface 11b of the glass plate 11, the pitch of the through holes 12 can be, for example, 10 μm or more and 1 mm or less. The pitch is determined from the distance between the centers of adjacent through holes 12.
[0075] In this embodiment, the through hole 12 of the glass plate 11 has a hole diameter enlargement portion 13. The hole diameter enlargement portion 13 is a portion of the through hole 12 where the hole diameter increases from the second main surface 11b side to the first main surface 11a side of the glass plate 11. A through hole 12 having such a hole diameter enlargement portion 13 can also be formed according to the glass plate 11 manufacturing method described above.
[0076] In this embodiment, the hole diameter enlargement portion 13 is provided on the first main surface 11a side of the center in the thickness direction of the glass plate 11. However, the hole diameter enlargement portion 13 may also be provided on the second main surface 11b side of the center in the thickness direction of the glass plate 11, and its position can be appropriately determined according to the desired shape of the through hole 12.
[0077] The ratio of the distance d3 between the first main surface 11a of the glass plate 11 and the hole diameter enlargement portion 13 to the distance L2 from the first main surface 11a to the second main surface 11b of the glass plate 11 (d3 / L2) is preferably 0.1 or more, more preferably 0.2 or more. The ratio of distance d3 to distance L2 (d3 / L2) is preferably 0.4 or less, more preferably 0.3 or less.
[0078] The through-hole 12 of the glass plate 11 in this embodiment has a first through-hole portion 12a and a second through-hole portion 12b. The first through-hole portion 12a is the portion of the through-hole 12 from the first main surface 11a to the hole diameter enlargement portion 13. The second through-hole portion 12b is the portion of the through-hole 12 from the hole diameter enlargement portion 13 to the second main surface 11b.
[0079] The taper angle θ1 of the inner surface of the through hole 12 in the first main surface 11a (first taper angle) can be determined from the angle between the straight line connecting the hole diameter enlargement portion 13 on the inner surface of the through hole 12 and the intersection point of the first main surface 11a and the inner surface of the through hole 12, and the direction along the first main surface 11a, in a cross-sectional view. The first taper angle θ1 is preferably 90° or more, more preferably 95° or more, and even more preferably 98° or more. The first taper angle θ1 is preferably 110° or less, more preferably 105° or less, and even more preferably 103° or less. Note that by having a hole diameter enlargement portion 13 in the through hole 12, the first taper angle θ1 can be made to be larger than 90° more reliably. On the other hand, by positioning the hole diameter enlargement portion 13 closer to the first main surface 11a than the center in the thickness direction of the glass plate 11, it is possible to prevent the diameter of the through-hole 12 on the first main surface 11a from becoming unnecessarily large, and to form the through-hole 12 at high density.
[0080] The taper angle θ2 of the inner surface of the through hole 12 on the second main surface 11b (second taper angle) can be determined from the angle between the straight line connecting the inner surface of the through hole 12 at a distance d3 from the second main surface 11b to the first main surface 11a and the hole diameter enlargement portion 13, and the direction along the second main surface 11b, in a cross-sectional view. The second taper angle θ2 is preferably 90° or more. The second taper angle θ2 is preferably 95° or less, more preferably 93° or less, and even more preferably 91° or less. Furthermore, it is preferable that the first taper angle θ1 is larger than the second taper angle θ2.
[0081] Furthermore, in this embodiment, the shape of the through hole 12 may have a locally narrowed portion (constriction) in the cross-section along the thickness direction of the glass plate 11. In this case, it is desirable that the narrowed portion be located on the second main surface 11b side of the center in the thickness direction of the glass plate 11. Such a through hole 12 having a narrowed portion can be formed, for example, according to the manufacturing method of the glass plate 11 described above. If the through hole 12 has a narrowed portion, when a conductive material is filled into the through hole 12 to provide a through electrode, the through electrode will be less likely to detach from the through hole 12. Also, when a conductive material is filled into the through hole 12 by plating or sputtering, the conductive material is more likely to accumulate in the narrowed portion, allowing for efficient formation of the through electrode.
[0082] In this embodiment, in a cross-section along the thickness direction of the glass plate 11, the shape of the through hole 12 may have a straight section with a uniform diameter in the second through hole portion 12b. In other words, the through hole 12 does not have to have a constricted portion (neck). Such a through hole 12 without a constricted portion can be manufactured, for example, by lowering the etching rate v2 in the double-sided etching process in the glass plate 11 manufacturing method described above. Having a straight section in the second through hole portion 12b of the through hole 12 prevents the minimum hole diameter from becoming unnecessarily small. Furthermore, since the straight section reaches the second main surface 11b, the minimum hole diameter can be controlled simply by measuring the hole diameter of the straight section.
[0083] As the glass constituting the glass plate 11, for example, the glass described in the glass plate 1 (original glass plate) used in the manufacturing method of the glass plate 11 described above can be used. In addition, in the manufacturing method of the glass plate 11 described above, since the glass plate 1 as the original glass plate is subjected to a single-sided etching process and a double-sided etching process, the etching rate of the parts other than the modified part 3 is lower than the etching rate of the modified part 3, but the parts other than the modified part 3 are also etched. For this reason, the thickness of the resulting glass plate 11 will be thinner than that of the glass plate 1.
[0084] The thickness of the glass plate 11 is preferably 1 μm or more, more preferably 10 μm or more, and even more preferably 20 μm or more. The thickness of the glass plate 11 is preferably 200 μm or less, more preferably 180 μm or less, and even more preferably 150 μm or less.
[0085] The glass plate 11 of this embodiment can be used, for example, as a glass plate having fine through-holes for wiring. For example, the glass plate 11 can be used as a substrate for electronic components such as core substrates and interposer substrates. In this case, a conductive material is filled inside the through-holes 12 to form through-electrodes. Also, for example, the glass plate 11 can be used as a filter used in inspection equipment and analysis equipment.
[0086] The present invention will be described in more detail below based on specific examples. The present invention is not limited in any way to the following examples, and can be implemented with appropriate modifications without changing its essence.
[0087] (Example) First, an alkali-free glass plate (manufactured by Nippon Electric Glass Co., Ltd., "OA-10G", 65 mm long x 80 mm wide x 50 μm thick) was prepared as the base glass plate. As the protective film, an ultraviolet curing sheet (manufactured by Nitto Denko Corporation, "ELPBM03", base material: polyolefin resin, adhesive layer: acrylic resin, 230 mm long x 10 mm wide x 135 μm thick) was prepared. For single-sided etching, an aqueous solution with a hydrofluoric acid concentration of 1.5 mol / L and a hydrochloric acid concentration of 0.2 mol / L was prepared. In addition, for double-sided etching, an aqueous solution with a sodium hydroxide concentration of 18 mol / L was prepared.
[0088] Next, a laser beam (Yb:YAG laser (wavelength: 515 nm)) was irradiated onto the planned through-hole formation location on the first main surface of the original glass plate to form a modified area extending from the first main surface to the second main surface of the original glass plate. At this time, one pulse was irradiated onto each planned through-hole formation location. The pulse width of the laser beam was approximately 10 picoseconds.
[0089] Next, a protective film was attached to the second main surface of the original glass plate. Then, with the protective film attached to the second main surface of the original glass plate, the original glass plate was immersed in an etching solution for single-sided etching, and the original glass plate was subjected to etching (single-sided etching), forming recesses in the modified parts of the original glass plate. For the single-sided etching, the temperature of the etching solution was set to 30°C, and the immersion time in the etching solution was set to 5 minutes.
[0090] Next, the adhesive layer of the protective film is irradiated with ultraviolet light (irradiation conditions: UV irradiation dose: 300 mJ / cm²). ２ The adhesive strength of the protective film was reduced by ) . After reducing the adhesive strength of the protective film, the protective film was peeled off from the second main surface of the original glass plate.
[0091] Next, with the protective film removed from the second main surface of the original glass plate, the original glass plate was immersed in an etching solution for double-sided etching, and the original glass plate was subjected to etching (double-sided etching) to produce a glass plate with through holes. During the double-sided etching process, the temperature of the etching solution was set to 90°C, and the immersion time in the etching solution was 2.5 hours. In this embodiment, a glass plate was produced with approximately 500,000 through holes and a pitch (distance between the centers of adjacent through holes) of approximately 20 μm. Furthermore, the average value of the hole diameter D1 of the through holes on the first main surface of the obtained glass plate was 10.57 μm, and the average value of the hole diameter D2 of the through holes on the second main surface was 6.89 μm.
[0092] Furthermore, the taper angle θ1 of the inner surface of the through hole 12 on the first main surface 11a (first taper angle) was 101.0°, and the taper angle θ2 of the inner surface of the through hole 12 on the second main surface 11b (second taper angle) was 90.0°.
[0093] Figure 4 is a photograph showing the through-hole in the glass plate fabricated in the embodiment. The photograph of the through-hole was obtained by taking a cross-sectional image along the thickness direction of the glass plate using an X-ray CT scanner. From the photograph in Figure 4, it can be seen that in the glass plate fabricated in the embodiment, a hole diameter expansion portion is formed in the through-hole, where the hole diameter increases from the second main surface side to the first main surface side. Notably, in the glass plate fabricated in the embodiment, no constriction (neck) was formed in the through-hole.
[0094] Figure 5 is a graph showing the change in hole diameter along the thickness direction in the through-holes of the glass plate fabricated in the embodiment. In Figure 5, the horizontal axis represents the distance (position) from the second main surface in the thickness direction of the glass plate, and the vertical axis represents the hole diameter at each position. The hole diameter at each position was determined from the average value of the hole diameters of the five through-holes.
[0095] Figure 5 shows that in the glass plate fabricated in the embodiment, there is a hole-diameter enlargement portion at a position 33.2 μm from the second main surface towards the first main surface, where the hole diameter in the through hole is larger. The distance d3 between the first main surface of the glass plate and the hole-diameter enlargement portion is 8.3 μm, and the distance L2 (thickness of the glass plate) from the first main surface to the second main surface of the glass plate is 41.5 μm. The ratio (d3 / L2) obtained from these values is 0.2.
[0096] As described above, in the glass plate manufactured by the manufacturing method of the embodiment, the hole diameter D1 of the through hole in the first main surface was larger than the hole diameter D2 of the through hole in the second main surface, and both the first taper angle θ1 and the second taper angle θ2 were 90° or more. Therefore, it was possible to manufacture a glass plate in which sharp angles are less likely to be formed on the glass plate at the intersection of the through hole and the first main surface, and at the intersection of the through hole and the second main surface, thus preventing the glass plate from breaking. Furthermore, in the manufacturing method of the embodiment, a protective film is attached to the second main surface of the original glass plate only during the single-sided etching process, and no protective film is attached during the double-sided etching process. Therefore, the time required to manufacture the glass plate can be shortened. Accordingly, the manufacturing method of the glass plate of the embodiment can increase the productivity of glass plates.
[0097] 1, 11…Glass plate 1a, 11a…First main surface 1b, 11b…Second main surface 2…Planned location for through-hole formation 3…Modified section 4…Protective film 5…Base material 5a…Main surface 6…Adhesive layer 7…Recess 7a…Bottom 12…Through-hole 12a…First through-hole section 12b…Second through-hole section 13…Hole diameter enlargement section θ1…First taper angle θ2…Second taper angle
Claims
1. A method for manufacturing a glass plate having through holes, comprising: a glass plate preparation step of preparing a glass plate having a first main surface and a second main surface which is the opposite surface of the first main surface; a laser light irradiation step of irradiating the first main surface of the glass plate with laser light at a position where through holes are to be formed to form a modified portion; a film application step of applying a protective film to the second main surface of the glass plate before or after the laser light irradiation step; a single-sided etching step of applying an etching treatment to the glass plate with the protective film applied to the second main surface of the glass plate; a film peeling step of peeling the protective film from the second main surface of the glass plate; and a double-sided etching step of applying an etching treatment to the glass plate with the protective film peeled from the second main surface of the glass plate to form through holes in the glass plate.
2. The method for manufacturing a glass plate according to claim 1, wherein the etching rate in the double-sided etching step is lower than the etching rate in the single-sided etching step.
3. The method for manufacturing a glass plate according to claim 2, wherein in the single-sided etching step, the glass plate is etched using an etching solution containing an aqueous hydrofluoric acid solution, and in the double-sided etching step, the glass plate is etched using an etching solution containing an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution.
4. A method for manufacturing a glass plate according to any one of claims 1 to 3, wherein the protective film comprises a base material and an adhesive layer provided on the main surface of one side of the base material, the base material being made of a polyolefin resin, and the adhesive layer being made of an acrylic resin.
5. A method for manufacturing a glass plate according to any one of claims 1 to 3, wherein in the single-sided etching step, the glass plate is subjected to etching to form a recess in the modified portion on the first main surface side of the glass plate, and in the film peeling step, the protective film is peeled off from the second main surface of the glass plate before the bottom of the recess on the glass plate reaches the second main surface.
6. The method for manufacturing a glass plate according to any one of claims 1 to 3, wherein the thickness of the glass plate is 200 μm or less.
7. A glass plate having a first main surface and a second main surface which is the opposite surface of the first main surface, and a through hole provided so as to extend from the first main surface to the second main surface, wherein the diameter of the through hole on the first main surface of the glass plate is larger than the diameter of the through hole on the second main surface, the first taper angle θ1 which is the taper angle of the inner surface of the through hole on the first main surface is 90° or more, and the second taper angle θ2 which is the taper angle of the inner surface of the through hole on the second main surface is 90° or more.
8. The glass plate according to claim 7, wherein the through hole of the glass plate has a hole diameter expansion portion in which the hole diameter in the through hole increases from the second main surface side to the first main surface side of the glass plate.
9. The glass plate according to claim 8, wherein the hole diameter enlargement portion in the through hole of the glass plate is provided on the first main surface side of the center in the thickness direction of the glass plate.
10. The glass plate according to any one of claims 7 to 9, wherein the first taper angle θ1 is greater than the second taper angle θ2.
11. The glass plate according to any one of claims 7 to 9, wherein in a cross section along the thickness direction of the glass plate, the shape of the through hole has a locally narrowed portion with a smaller hole diameter, and the narrowed portion is provided on the second main surface side of the center in the thickness direction of the glass plate.
12. The glass plate according to any one of claims 7 to 9, wherein in a cross section along the thickness direction of the glass plate, the shape of the through hole has a straight portion with a uniform hole diameter.
13. The glass plate according to any one of claims 7 to 9, wherein the first main surface and the second main surface of the glass plate are etched surfaces.