Method for manufacturing glass substrate with through-hole, and glass substrate with through-hole

Abstract

This method comprises: a step for irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through-hole, the initial through-hole having a first initial opening on the first surface and a second initial opening on the second surface; a step for performing a first wet etching on the glass substrate at an etching rate in the range of 0.04 μm / min to 0.20 μm / min with a masking material installed so as to close the initial opening having the larger diameter in the initial through-hole, whereby a first through-hole is formed from the initial through-hole; and a step for performing a second wet etching on the glass substrate with the masking material removed.

Description

METHOD FOR PRODUCING GLASS SUBSTRATE WITH THRU-HOLE AND GLASS SUBSTRATE WITH THRU-HOLE

[0001] The present invention relates to a method for manufacturing a glass substrate with a through hole and a glass substrate with a through hole.

[0002] 2. Description of the Related Art Conventionally, a technique for forming a through hole in a glass substrate by irradiating the glass substrate with laser light has been known.

[0003] For example, Patent Document 1 discloses CO ２ A method for forming through holes in a glass substrate using a laser is disclosed.

[0004] Japanese Patent Application Laid-Open No. 2016-113358

[0005] In the above-mentioned techniques for forming through holes in glass substrates, a problem often arises in that through holes cannot be formed in the desired shape.

[0006] For example, in conventional methods, the through hole after processing may have a slope from one surface to the other (a so-called "tapered shape"), or may have "necks" and "bulges" (hereinafter collectively referred to as "non-straight portions") along the extension direction of the through hole.

[0007] When through holes that deviate from the predetermined shape are formed in a glass substrate, it may be difficult to properly fill the through holes with a conductive material in a subsequent process. Furthermore, when a current is applied to a glass substrate in which such conductive material is unevenly filled in the through holes, energy loss may occur.

[0008] The present invention has been made in view of the above background, and an object of the present invention is to provide a method for manufacturing a glass substrate with through holes that is capable of forming through holes having shapes closer to the desired shapes. Another object of the present invention is to provide a glass substrate having through holes having shapes closer to the desired shapes.

[0009] The present invention provides a method for manufacturing a glass substrate with a through hole, the method comprising the steps of: (1) irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through hole, the initial through hole having a first initial opening in the first surface and a second initial opening in the second surface; (2) performing first wet etching on the glass substrate at a first etching rate in a state in which a masking material is placed so as to cover the first initial opening or the second initial opening of the initial through hole, whichever has a larger diameter, the first etching rate being in a range of 0.04 μm / min to 0.20 μm / min, thereby forming a first through hole from the initial through hole; and (3) performing second wet etching on the glass substrate in a state in which the masking material is removed, thereby forming a second through hole from the first through hole.

[0010] The present invention also provides a glass substrate with a through hole, comprising: a glass substrate having a first surface and a second surface opposed to each other; and at least one through hole penetrating the glass substrate from the first surface to the second surface, wherein the glass substrate has a thickness in the range of 0.05 mm to 1.2 mm, and the through hole has a diameter φ １ and a first opening of diameter φ ２ a second opening having a diameter φ of the first opening; １ and the diameter φ of the second opening ２ The absolute value of the difference Δφ is 5 μm or less, and the position in the through hole where the dimension of the cross section perpendicular to the extension axis of the through hole is smallest is called a narrowed portion, and in the cross section along the extension axis of the through hole, one end of the first opening is called a first end P １Ａ and the other end is the second end P １Ｂ and the first end P of the second opening １Ａ The end on the same side as the third end P ２Ａ and the second end P of the second opening １Ｂ The end on the same side as２Ｂ and the first end P of the narrowed portion １Ａ The end on the same side as the fifth end P ｍＡ and the second end P of the narrowed portion １Ｂ The end on the same side as the sixth end P ｍＢ and the first end P １Ａ and the fifth end P ｍＡ The line segment connecting １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment connecting １Ｂ and the third end P ２Ａ and the fifth end P ｍＡ The line segment connecting ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment connecting ２Ｂ and the first end P １Ａ A perpendicular line is drawn from the line segment L １Ａ The angle between the first and second taper angles θ １ｆｕ and the second end P １Ｂ A perpendicular line is drawn from the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ and the third end P ２Ａ A perpendicular line is drawn from the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ and the fourth end P ２Ｂ A perpendicular line is drawn from the line segment L ２Ｂ The angle between the first and second taper angles is defined as the second downward taper angle θ ２ｆｄ and the θ １ｆｕ , θ ２ｆｕ , θ １ｆｄ , and θ ２ｆｄ The average of the taper angle θ ａｖｅ When the taper angle θ is ａｖｅ is less than 4°, and in the cross section along the extension axis of the second through hole, the first end P １Ａ and the fifth end P ｍＡThe side wall portion between the second end P １Ｂ and the sixth end P ｍＢ The side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ The side wall portion between the first side wall and the line segment L is defined as a fourth side wall. １Ａ The maximum distance between the two points is B. １ and the second side wall and the line segment L １Ｂ The maximum distance between the two points is B. ２ and the third side wall and the line segment L ２Ａ The maximum distance between the two points is B. ３ and the fourth side wall and the line segment L ２Ｂ The maximum distance between the two points is B. ４ and the bulge B １ ~B ４ The largest value among B ｍａｘ When called, the maximum bulge B ｍａｘ is 5 μm or less, and when the distance of the through hole from the first opening in the depth direction is x (μm) and the surface roughness (maximum height Rz) of the side wall of the through hole is Q (μm), the relationship between Q and x can be approximated by the following equation: Q=mx+b (1), where a slope m is in the range of: (a) -0.001 to -0.005, or (b) 0.001 to 0.005.

[0011] The present invention can provide a method for manufacturing a glass substrate with through holes, which can form through holes having shapes closer to the desired shape. Also, the present invention can provide a glass substrate having through holes having shapes closer to the desired shape.

[0012] FIG. 1 is a diagram schematically illustrating a flow of a method for manufacturing a glass substrate with through holes according to one embodiment of the present invention. FIG. 2 is a diagram schematically illustrating a cross section of a glass substrate in a process of the method according to one embodiment of the present invention. FIG. 3 is a diagram schematically illustrating a cross section of a glass substrate in a process of the method according to one embodiment of the present invention. FIG. 4 is a diagram schematically illustrating a cross section of a glass substrate in a process of the method according to one embodiment of the present invention. FIG. 5 is a diagram schematically illustrating a cross section of a glass substrate in a process of the method according to one embodiment of the present invention. FIG. 6 is a diagram schematically illustrating an enlarged view of a cross section along the extension axis L of a through hole after processing formed by a method according to one embodiment of the present invention. FIG. 7 is a diagram schematically illustrating an enlarged view of a cross section along the extension axis L of a through hole after processing formed by a method according to one embodiment of the present invention. FIG. 8 is a diagram schematically illustrating an example of a cross section of a glass substrate with through holes according to one embodiment of the present invention. FIG. 9 is a photograph showing an example of the cross-sectional shape of a first through hole obtained by one embodiment of the present invention (Example 1). FIG. 10 is a photograph showing an example of the cross-sectional shape of a first through hole obtained by another embodiment of the present invention (Example 2). 1 is a photograph showing an example of the cross-sectional shape of a first through hole obtained by yet another embodiment (Example 3) of the present invention. 2 is a photograph showing an example of the cross-sectional shape of a first through hole obtained by a comparative example (Example 21). 3 is a photograph showing an example of the cross-sectional shape of a first through hole obtained by a comparative example (Example 22). 4 is a photograph showing an example of the cross-sectional shape of a second through hole obtained by one embodiment of the present invention (Example 1). 5 is a photograph showing an example of the cross-sectional shape of a second through hole obtained by one embodiment of the present invention (Example 2). 6 is a graph showing the relationship between the depth position and surface roughness of the side wall of a through hole obtained in a glass substrate with a through hole according to one embodiment of the present invention (Sample 1). 7 is a graph showing the relationship between the depth position and surface roughness of the side wall of a through hole obtained in a conventional glass substrate with a through hole (Sample 23). 8 is a photograph showing an example of the cross section of a second through hole in a glass substrate with a through hole according to one embodiment of the present invention (Sample 1), taken with a laser microscope.10 is a photograph taken with a laser microscope showing an example of a cross section of a second through hole in a conventional glass substrate with a through hole (sample 23).

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0014] As described above, conventional glass substrates with through holes have through holes with a "tapered shape" and / or through holes with a "non-straight portion." When through holes that deviate from the predetermined shape are formed, it may be difficult to properly fill the through holes with a conductive material in a subsequent process. Furthermore, when a glass substrate with through holes unevenly filled with such conductive material is used to conduct electricity, energy loss may occur.

[0015] In contrast, one embodiment of the present invention provides a method for manufacturing a glass substrate with a through hole, the method comprising the steps of: (1) irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through hole, the initial through hole having a first initial opening in the first surface and a second initial opening in the second surface; (2) performing first wet etching on the glass substrate at a first etching rate in a state where a masking material is placed so as to cover the first initial opening or the second initial opening of the initial through hole, whichever has a larger diameter, the first etching rate being in a range of 0.04 μm / min to 0.20 μm / min, thereby forming a first through hole from the initial through hole; and (3) performing second wet etching on the glass substrate in a state where the masking material is removed, thereby forming a second through hole from the first through hole.

[0016] In a method according to an embodiment of the present invention, after the initial through hole is formed by laser processing, the glass substrate is subjected to a first wet etching process, and in this process, a masking material is placed on the larger diameter of the first initial opening or the second initial opening of the initial through hole (e.g., the first initial opening).

[0017] When the first wet etching is performed under these conditions, the etching solution is introduced into the through hole from the side of the initial opening having the smaller diameter. This increases the amount of etching on the side of the initial opening having the smaller diameter, thereby reducing the difference in diameter between the two openings in the resulting first through hole. This significantly reduces the "tapered shape" of the first through hole.

[0018] Furthermore, the first wet etching significantly reduces non-straight portions such as "necks" and "bulges."

[0019] If the etching rate in the first wet etching is too high, problems such as "non-straight portions" and a large taper angle may occur.

[0020] However, in one embodiment of the present invention, the etching rate of the first wet etching is adjusted to a relatively low etching rate in the range of 0.04 μm / min to 0.20 μm / min, thereby avoiding the occurrence of the above-mentioned problems.

[0021] Thereafter, a second wet etch is performed to globally adjust the dimensions of the first through-holes to form second through-holes.

[0022] As a result of the above-described effects, in one embodiment of the present invention, it is possible to form first through holes and second through holes having shapes closer to the desired shapes.

[0023] (Method for Manufacturing a Glass Substrate with Through Holes According to an Embodiment of the Present Invention) Hereinafter, a method for manufacturing a glass substrate with through holes according to an embodiment of the present invention will be described in more detail with reference to the drawings.

[0024] FIG. 1 is a schematic diagram showing the flow of a method for manufacturing a glass substrate with through holes according to one embodiment of the present invention.

[0025] As shown in FIG. 1 , a method for manufacturing a glass substrate with a through hole according to one embodiment of the present invention (hereinafter referred to as a “first method”) includes: (1) a step (S110) of irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through hole, the initial through hole having a first initial opening on the first surface and a second initial opening on the second surface; and (2) a step (S120) of performing a first wet etching on the glass substrate at a first etching rate in a state in which a masking material is placed so as to cover an initial opening having a larger diameter out of the first initial opening and the second initial opening of the initial through hole, the first etching rate being in a range of 0.04 μm / min to 0.20 μm / min, thereby forming a first through hole from the initial through hole. (3) A step (S130) of performing a second wet etching process on the glass substrate with the masking material removed, thereby forming a second through hole from the first through hole.

[0026] Each step will be described below.

[0027] (Step S110) First, a glass substrate having first and second surfaces facing each other is prepared.

[0028] The composition of the glass substrate is not particularly limited. The glass substrate may be made of, for example, soda-lime glass or alkali-free glass. The thickness of the glass substrate is not particularly limited. The glass substrate may have a thickness of, for example, 0.05 mm to 1.2 mm.

[0029] Next, the glass substrate is irradiated with laser light from the first surface side, and an initial through hole is formed in the glass substrate.

[0030] The laser beam to be irradiated is not particularly limited as long as it can form an initial through hole in the glass substrate. ２ It may also be a laser.

[0031] FIG. 2 is a schematic cross-sectional view of a glass substrate in which an initial through hole has been formed.

[0032] 2, the glass substrate 110 has a first surface 112 and a second surface 114 that face each other. The first surface 112 is the surface that is irradiated with the laser.

[0033] An initial through-hole 120 is formed in the glass substrate 110, penetrating from the first surface 112 to the second surface 114.

[0034] 2 shows a single initial through hole 120. However, the number of initial through holes 120 is not particularly limited. For example, when the glass substrate 110 is used for an application such as a glass interposer, a large number of initial through holes 120, such as more than 10,000, may be formed in the glass substrate 110.

[0035] The initial through hole 120 has a first initial opening 122 in the first surface 112 and a second initial opening 124 in the second surface 114 .

[0036] The diameter φ of the first initial opening 122 ｓ１ is the diameter φ of the second initial opening 124 ｓ２ is larger than φ ｓ１ >φ ｓ２ Alternatively, the diameter φ of the first initial opening 122 may be ｓ１ is the diameter φ of the second initial opening 124 ｓ２ is smaller than φ ｓ１ <φ ｓ２ may be.

[0037] φ ｓ１ >φ ｓ２ In this case, the diameter φ of the first initial opening 122 ｓ１ is not limited to this, but is in the range of 20 μm to 200 μm, for example. ｓ２ Although not limited to this, it is in the range of 10 μm to 150 μm, for example.

[0038] After step S110 and before the next step S120, a step of annealing the glass substrate 110 may be performed.

[0039] Annealing the glass substrate 110 can relieve stress that has accumulated in the glass substrate 110 due to laser processing, thereby reducing the risk of cracks occurring in the glass substrate 110 in subsequent steps.

[0040] The annealing temperature is not particularly limited, but is, for example, in the range of 300°C to 1500°C.

[0041] (Step S120) Next, a masking material is placed on the initial opening having the larger diameter out of the first initial opening 122 and the second initial opening 124 of the initial through hole 120.

[0042] Here, as an example, φ ｓ１ >φ ｓ２ Assuming that the masking material 130 is placed in the first initial opening 122, an example will be described.

[0043] FIG. 3 shows a schematic cross section of a glass substrate 110 with a masking material 130 provided on the first surface 112 side.

[0044] As shown in FIG. 3, the masking material 130 is placed so as to cover the first initial opening 122 .

[0045] The form of the masking material 130 is not particularly limited. The masking material 130 may be, for example, in the form of a film. Furthermore, the material of the masking material 130 is not particularly limited. The masking material 130 may be, for example, a resin film or a metal film. Furthermore, the thickness of the masking material 130 is not particularly limited, and a masking material 130 of a general thickness may be used.

[0046] 3, the masking material 130 is disposed so as to mask only the first initial opening 122 (and its periphery). However, this is merely an example, and the manner in which the masking material 130 is disposed is not particularly limited as long as it is capable of blocking the first initial opening 122. For example, the masking material 130 may be disposed over the entire first surface 112.

[0047] Next, in this state, a first wet etching is performed on the glass substrate 110. As a result, a first through hole is formed from the initial through hole 120.

[0048] The etching solution used in the first wet etching is not particularly limited as long as it can perform appropriate etching on the glass substrate 110 .

[0049] For example, a hydrofluoric acid solution may be used as the etching solution.

[0050] Furthermore, the conditions such as etching temperature and time are not particularly limited, and general conditions for wet etching of glass may be selected.

[0051] By carrying out the first wet etching in this manner, a larger amount of etching can be achieved on the side of the second initial opening 124 of the initial through hole 120 than on the side of the first initial opening 122.

[0052] As a result, the resulting first through hole has a significantly reduced "tapered shape" and a reduced "non-straight portion" such as a constriction / bulge.

[0053] The masking material 130 is then removed.

[0054] 4 shows a schematic cross section of the glass substrate 110 after the first wet etching has been performed. FIG. 4 also shows a cross section of the glass substrate 110 after the masking material 130 has been removed.

[0055] 4, the first through-hole 140 has a first opening 142 on the side of the first surface 112 of the glass substrate and a second opening 144 on the side of the second surface 114 of the glass substrate. The first opening 142 has a diameter φ ｍ１ and the second opening 144 has a diameter φ ｍ２ It has.

[0056] As described above, in the first wet etching, the etching rate is adjusted to be in the range of 0.04 μm / min to 0.20 μm / min.

[0057] Here, the diameter difference between the two openings, i.e., φ ｍ１ -φｍ２ The absolute value of is the difference in diameter between the two openings of the initial through hole 120, i.e., φ ｓ１ -φ ｓ２ It should be noted that the absolute value of is significantly smaller than that of

[0058] 3, the first surface 112 and the second surface 114 of the glass substrate 110 are also etched. Therefore, in the obtained glass substrate 100, both opposing surfaces become new surfaces that are different from the first surface 112 and the second surface 114 before the first wet etching is performed.

[0059] However, in this application, to avoid complicating the explanation, the opposing surfaces of the glass substrate 110 after the first wet etching are referred to as the "first surface" 112 and the "second surface" 114. The same applies to the surfaces after the second and subsequent etching processes.

[0060] On the other hand, when the first wet etching is performed with the masking material 130 applied to the entire first surface 112 of the glass substrate 110, the first surface 112 is the original surface.

[0061] (Step S130) Next, a second wet etching is performed on the glass substrate 110. As a result, a second through hole is formed from the first through hole 140.

[0062] The second wet etching is carried out to shape the final through-hole (i.e., the second through-hole).

[0063] The etching solution used in the second wet etching is not particularly limited as long as it can perform appropriate etching on the glass substrate 110 .

[0064] The etching solution used in the second wet etching may be the same as or different from the etching solution used in the first wet etching described above.

[0065] In the second wet etching, the conditions such as etching temperature and time are not particularly limited, and general conditions for wet etching of glass may be selected.

[0066] The etching rate of the second wet etching is, for example, in the range of 0.01 μm / min to 5 μm / min.

[0067] FIG. 5 shows a schematic cross section of the glass substrate 110 after the second wet etching has been performed.

[0068] 5, the second through-hole 150 has a first post-machining opening 152 on the side of the first surface 112 of the glass substrate, and a second post-machining opening 154 on the side of the second surface 114 of the glass substrate. The first post-machining opening 152 has a diameter φ ｆ１ and the second machined opening 154 has a diameter φ ｆ２ It has.

[0069] By the above steps, a glass substrate with a through hole can be manufactured.

[0070] In this first method, step S120 reduces the tapered shape and the non-straight portion, resulting in a more cylindrical first through hole 140. Therefore, even after the subsequent step S130, in which a second wet etching process is performed to evenly widen the shape of first through hole 140, the resulting second through hole 150 maintains a shape that is close to a cylindrical shape.

[0071] As a result of the above effects, in one embodiment of the present invention, the second through-hole 150 can be formed in a shape closer to the desired shape.

[0072] (Regarding the shape characteristics of the through holes obtained by the manufacturing method of a glass substrate with through holes according to one embodiment of the present invention) Next, with reference to Figures 6 to 8, the shape characteristics of the through holes (e.g., corresponding to the second through hole 150 in Figure 5) obtained by the manufacturing method of a glass substrate with through holes according to one embodiment of the present invention will be described in more detail.

[0073] FIG. 6 is a schematic enlarged view of a cross section along the stretching axis of a through hole (hereinafter referred to as a "processed through hole") obtained in a method for manufacturing a glass substrate with through holes according to one embodiment of the present invention.

[0074] It should be noted that the shape of the through hole after machining is exaggerated in Fig. 6 for the sake of clarity in the following explanation. It should be noted that the shape of the through hole after machining that is actually obtained will be closer to a "cylindrical" shape.

[0075] 6, the post-machining through-hole 250 has a first post-machining opening 252 on the side of the first surface 212 of the glass substrate 210 and a second post-machining opening 254 on the side of the second surface 214 of the glass substrate 210. The first post-machining opening 252 has a diameter φ ｆ１ and the second machined opening 254 has a diameter φ ｆ２ It has.

[0076] Furthermore, the through hole 250 after processing has a narrowed portion 260 .

[0077] Here, the narrowed portion 260 means a position (surface) in the through hole 250 after processing where the dimension of the cross section perpendicular to the stretching axis L is smallest. The narrowed portion 260 has a diameter φ ｆｍｉｎ It has.

[0078] In one embodiment of the present invention, the diameter φ of the first post-machining opening 252 in the post-machining through-hole 250 ｆ１ and the diameter φ of the second post-machining opening 254 ｆ２ The absolute value Δφ of the difference between the above values ​​may be 5 μm or less. In particular, Δφ is preferably, for example, 3.5 μm or less, or 3 μm or less, and more preferably 1 μm or less.

[0079] In one embodiment of the present invention, as in the first method described above, the first wet etching is performed with a masking material placed on the initial opening with the larger diameter. This reduces the difference in diameter between the first and second initial openings. Therefore, the through hole 250 obtained after the second wet etching can have a Δφ of 5 μm or less.

[0080] Next, Fig. 7 shows an enlarged schematic view of a cross section of the through-hole 250 after processing taken along the extension axis L, similar to Fig. 6. In Fig. 7, the shape of the through-hole 250 after processing is also shown exaggerated.

[0081] In one embodiment of the present invention, the through hole 250 after processing has a taper angle θ ａｖｅ " is significantly suppressed.

[0082] The taper angle θ ａｖｅ is defined as follows:

[0083] As shown in FIG. 7, one end of the first post-machining opening 252 is connected to the first end P １Ａ and the other end is the second end P １Ｂ Similarly, in the second processed opening 254, the first end P １Ａ The end on the same side as the third end P ２Ａ and the second end P １Ｂ The end on the same side as ２Ｂ Furthermore, in the narrowed portion 260, the first end P １Ａ The end on the same side as the fifth end P ｍＡ and the second end P １Ｂ The end on the same side as the sixth end P ｍＢ Let's say.

[0084] Next, the first end P １Ａ and the fifth end P ｍＡ The line segment obtained by connecting the above with a straight line is called line segment L. １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment obtained by connecting the above with a straight line is called line segment L. １B In addition, the third end P ２Ａ and the fifth end P ｍＡ The line segment obtained by connecting the above with a straight line is called line segment L. ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment obtained by connecting the above with a straight line is called line segment L. ２Ｂ Let's say.

[0085] Next, the first end P １Ａ A perpendicular line is drawn from the center of the glass substrate 210 toward the inside of the glass substrate 210, and the perpendicular line is connected to the line segment L １ＡThe angle between the first and second taper angles θ １ｆｕ Similarly, the second end P １Ｂ A perpendicular line is drawn from the center of the glass substrate 210 toward the inside of the glass substrate 210, and the perpendicular line is connected to the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ Let's say.

[0086] Similarly, the third end P ２Ａ A perpendicular line is drawn from the center of the glass substrate 210 toward the inside of the glass substrate 210, and the perpendicular line is connected to the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ Similarly, the fourth end P ２Ｂ A perpendicular line is drawn from the center of the glass substrate 210 toward the inside of the glass substrate 210, and the perpendicular line is connected to the line segment L ２Ｂ The angle between the first and second taper angles is defined as the second downward taper angle θ ２ｆｄ Let's say.

[0087] Four angles: a first upper taper angle θ １ｆｕ , second upper taper angle θ ２ｆｕ , first lower taper angle θ １ｆｄ , and a second lower taper angle θ ２ｆｄ The average of the taper angle θ ａｖｅ It is stipulated that:

[0088] In one embodiment of the present invention, for example, the taper angle θ ａｖｅ is less than 4°. ａｖｅ is preferably less than 3.5°, and more preferably less than 3.0°.

[0089] Depending on the cross-sectional shape of the through-hole 250 after machining, the diameter φ of the first opening 252 after machining may be ｆ１ or the diameter φ of the second post-machining opening 254 ｆ２ may correspond to the position where the dimension of the cross section perpendicular to the stretching axis L is smallest. In this case, the narrowed portion 260 coincides with the first post-processing opening 252 or the second post-processing opening 254.

[0090] In such a case, the above taper angle θ ａｖｅ In the method for determining １Ａ and the third end P ２Ａ The line segment connecting １ ', and the second end P １Ｂand the fourth end P ２B The line segment connecting ２ ' is sufficient.

[0091] That is, when the narrowed portion 260 coincides with the second post-machining opening 254, the line segment L １ ' and the first end P １Ａ A first upper taper angle θ obtained from a perpendicular line drawn from １ｆｕ and line segment L ２ ' and the second end P １Ｂ A second upper taper angle θ obtained from a perpendicular line drawn from ２ｆｕ Average the taper angle θ ａｖｅ is required.

[0092] Similarly, when the narrowed portion 260 coincides with the first post-machining opening 252, the line segment L １ ' and the third end P ２Ａ A first downward taper angle θ obtained from a perpendicular line drawn from １ｆｄ and line segment L ２ ' and the fourth end P ２Ｂ A second downward taper angle θ obtained from a perpendicular line drawn from ２ｆｄ Average the taper angle θ ａｖｅ is required.

[0093] Next, Fig. 8 shows an enlarged schematic view of a cross section of the through hole 250 after processing taken along the extension axis L, similar to Fig. 6. In Fig. 8, the shape of the through hole 250 after processing is also exaggerated.

[0094] In one embodiment of the present invention, the through-hole 250 after processing has a “bulge B ｍａｘ " is significantly suppressed.

[0095] In addition, bulge B ｍａｘ is defined as follows:

[0096] The aforementioned taper angle θ ａｖｅ Similarly to the case of finding the first end P １Ａ , second end P １Ｂ , third end P ２Ａ , the fourth end P ２Ｂ , fifth end P ｍＡ , and the sixth end P ｍＢ The following is established.

[0097] In addition, the aforementioned taper angle θ ａｖｅ As in the case of finding １Ａ , line segment L １Ｂ , line segment L ２Ａ , and the line segment L ２Ｂ get.

[0098] In addition, in the through hole 250 after processing, the first end P １Ａ and the fifth end P ｍＡ The side wall portion between the first end P １Ｂ and the sixth end P ｍＢ The side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ The side wall portion between these is defined as a fourth side wall 263d.

[0099] The first side wall 263a and the line segment L １Ａ The maximum distance between the two points is B. １ (position S １ ). Also, the second side wall 263b and the line segment L １Ｂ The maximum distance between the two points is B. ２ (position S ２ Similarly, the third side wall 263c and the line segment L ２Ａ The maximum distance between the two points is B. ３ (position S ３ ). The fourth side wall 263d and the line segment L ２Ｂ The maximum distance between the two points is B. ４ (position S ４ ).

[0100] Four bulges B １ ~B ４ The largest value among B ｍａｘ It is stipulated that:

[0101] In one embodiment of the present invention, the bulge B thus defined ｍａｘ is, for example, 5 μm or less. ｍａｘ is preferably 4 μm or less.

[0102] As described above, when the narrowed portion 260 coincides with the first post-machining opening 252 or the second post-machining opening 254, the bulge B ｍａｘ is the taper angle θ ａｖｅ It is evaluated in the same way as for

[0103] That is, the line segment L drawn as described above １ ' and the line segment L １ From the maximum distance between the line segment L′ and the corresponding side wall, one bulge B of the through hole 250 after processing can be obtained. ２ ' and the line segment L ２ Another bulge B is calculated from the maximum distance between the sidewall of the corresponding side and the bulge B of the through-hole 250 after machining. ｍａｘ It is defined as follows.

[0104] (Glass Substrate with Through Holes According to One Embodiment of the Present Invention) Next, with reference to FIG. 9, a glass substrate with through holes according to one embodiment of the present invention will be described.

[0105] Fig. 9 is a schematic diagram showing an example of a cross section of a glass substrate with through holes according to one embodiment of the present invention. Note that Fig. 9 shows the shape of the through holes in an exaggerated manner.

[0106] As shown in FIG. 9, a glass substrate with a through hole (hereinafter referred to as a "first substrate") 300 according to one embodiment of the present invention has a glass substrate 310 having a first surface 312 and a second surface 314 facing each other.

[0107] The glass substrate 310 has a thickness in the range of, for example, 0.05 mm to 1.2 mm.

[0108] The first substrate 300 also has at least one through-hole 350 that penetrates from the first surface 312 to the second surface 314 .

[0109] 9, the first substrate 300 has a single through-hole 350. However, the number of through-holes 350 is not particularly limited. For example, when the first substrate 300 is used in an application such as a glass interposer, a large number of through-holes 350, such as more than 10,000, may be formed in the first substrate 300.

[0110] Each through-hole 350 has a first opening 352 in the first surface 312 and a second opening 354 in the second surface 314. The through-holes 350 may also have a constriction 360.

[0111] The diameter of the first opening 352 is φ １ and the diameter of the second opening 354 is φ ２ and the diameter of the constriction 360 is φ ｍｉｎ is.

[0112] Here, in the first substrate 300, the "tapered shape" of the through-hole 350 is significantly reduced, and the "non-straight portion" is also significantly reduced.

[0113] Specifically, in the first substrate 300, each through-hole 350 has the following characteristics: (i) Δφ (absolute value) is 5 μm or less; (ii) the taper angle θ ａｖｅ is 4° or less; and (iii) bulge B ｍａｘ is typically 5 μm or less.

[0114] In addition, Δφ (absolute value) and taper angle θ ａｖｅ , and bulge B ｍａｘ is determined as defined in the above-mentioned FIGS.

[0115] In particular, Δφ (absolute value) is preferably 3.5 μm or less, or 3 μm or less, and more preferably 1 μm or less. ａｖｅ is preferably less than 3.5°, and more preferably less than 3.0°. ｍａｘ is preferably less than 4 μm, more preferably less than 3 μm.

[0116] By having the through-hole 350 have such a shape, the through-hole 350 can be properly filled with a conductive material in the first substrate 300. Furthermore, this makes it possible to significantly suppress the occurrence of energy loss when electricity is passed through the first substrate 300 in which the through-hole 350 is filled with a conductive material.

[0117] Furthermore, the first substrate 300 has a feature in that the surface roughness (maximum height Rz; the same applies below) of the sidewall 363 of the through-hole 350 varies along the extension axis L of the through-hole 350 .

[0118] Specifically, when the depth direction distance from the first opening 352 of the through hole 350 is x (μm) and the surface roughness (maximum height Rz) of the side wall 363 of the through hole 350 is Q (μm), the relationship between Q and x can be approximated by the following equation: Q = mx + b (1).

[0119] In equation (1), the slope m is: (a) in the range of 0.001 to 0.005, or (b) in the range of −0.001 to −0.005.

[0120] Due to these characteristics, the first substrate 300 allows the conductive material to be more uniformly deposited within the through-hole 350. That is, generally, the sidewall of a through-hole with a large surface roughness tends to have a conductive material adhere thereto more easily than the sidewall of a through-hole with a small surface roughness. Therefore, when depositing the conductive material within the through-hole 350, if the conductive material is introduced through the opening corresponding to the sidewall 363 with the small surface roughness, the conductive material can be sufficiently deposited up to the opening on the opposite side corresponding to the sidewall 363 with the large surface roughness.

[0121] The first substrate 300 having the above-described characteristics can be manufactured by a method according to one embodiment of the present invention, such as the first method described above.

[0122] That is, in the method according to the embodiment of the present invention, a masking material is applied to the larger opening of the initial through hole during the first etching process, so that the etching solution is more pronounced on the side of the smaller opening where the masking material is not applied, and the sidewall is etched by a larger amount.

[0123] As a result, the sidewall surface is smoother on the small opening side of the initial through hole than on the large opening side, resulting in a surface roughness (maximum height Rz) that is "graded" in the depth direction of the through hole.

[0124] Examples of the present invention will be described below. In the following description, Examples 1 to 3 are examples, and Examples 21 to 23 are comparative examples.

[0125] Example 1 A glass substrate with through holes was produced by the following method.

[0126] First, a glass substrate having a first surface and a second surface facing each other was prepared.

[0127] The glass substrate used was a non-alkali glass substrate having a length of 50 mm, a width of 50 mm and a thickness of 0.23 mm.

[0128] Next, the first surface of the glass substrate was irradiated with laser light to form three initial through holes.

[0129] The laser beam has a wavelength of 10.6 μm. ２ A laser was used, and the output was set to 100 W.

[0130] The resulting initial through hole had a first initial opening on a first surface of the glass substrate and a second initial opening on a second surface, the diameter of the first initial opening being larger than the diameter of the second initial opening.

[0131] Thereafter, the glass substrate was subjected to an annealing treatment in the atmosphere.

[0132] Next, a masking material was placed so as to cover the first initial opening of each initial through hole. Specifically, the masking material was placed over the entire first surface of the glass substrate. A resin film (331B-N; manufactured by 3M Company) was used as the masking material.

[0133] Next, a first etching process was performed on the glass substrate.

[0134] In the first etching process, a hydrofluoric acid solution was used as the etching solution. The etching rate was set to 0.073 μm / min. As a result, the initial through holes were transformed into first through holes.

[0135] The resulting first through-hole had a first opening on a first surface of the glass substrate and a second opening on a second surface thereof, the diameter of the first opening being larger than the diameter of the second opening.

[0136] Next, the masking material was removed from the glass substrate, and a second etching process was carried out.

[0137] In the second etching treatment, an alkaline solution was used as the etching solution, and the etching rate was set to 0.07 μm / min. As a result, the first through holes were transformed into second through holes.

[0138] The resulting second through-hole has a first post-processing opening on the first surface of the glass substrate and a second post-processing opening on the second surface.

[0139] Through the above steps, a glass substrate with through holes (hereinafter referred to as "Sample 1") was obtained.

[0140] Example 2 A glass substrate with a through hole was produced in the same manner as in Example 1.

[0141] However, in this Example 2, the concentration of the etching solution in the first etching process was changed, and the etching rate was set to 0.12 μm / min.

[0142] The obtained glass substrate with through holes is referred to as "Sample 2."

[0143] Example 3 A glass substrate with a through hole was produced in the same manner as in Example 1.

[0144] However, in this Example 3, the concentration of the etching solution in the first etching process was changed, and the etching rate was set to 0.18 μm / min.

[0145] The obtained glass substrate with through holes is referred to as "Sample 3."

[0146] Example 21 In the same manner as in Example 1, a glass substrate with a through hole was produced.

[0147] However, in this Example 21, the concentration of the etching solution in the first etching process was changed, and the etching rate was set to 0.03 μm / min.

[0148] The obtained glass substrate with through holes is referred to as "Sample 21."

[0149] Example 22 In the same manner as in Example 1, a glass substrate with a through hole was produced.

[0150] However, in this Example 22, the concentration of the etching solution in the first etching process was changed, and the etching rate was set to 0.31 μm / min.

[0151] The obtained glass substrate with through holes is referred to as "Sample 22."

[0152] Example 23 In the same manner as in Example 1, a glass substrate with a through hole was produced.

[0153] However, in this Example 23, only the second etching process was performed.

[0154] The obtained glass substrate with through holes is referred to as "Sample 23."

[0155] (Evaluation) The glass substrates formed in the above examples were subjected to the following evaluations.

[0156] (Measurement of Shape of Through Hole) In each example, the shape of the first through hole after the first etching treatment and the shape of the second through hole after the second etching treatment were evaluated.

[0157] Specifically, a cross section along the stretching axis was prepared for each of the first and second through holes (three for each). The cross sections of the obtained through holes were observed with an optical microscope to measure each dimension.

[0158] All dimensions below are the average of measurements taken on three through holes.

[0159] 10 to 14 show examples of cross-sectional shapes of the first through holes in Examples 1 to 3 and Examples 21 and 22, respectively. Also, FIGS. 15 to 17 show examples of cross-sectional shapes of the second through holes in Examples 1, 2, and 22, respectively.

[0160] Table 1 below shows the results of measuring the dimensions of the first through holes formed in each example.

[0161] Table 2 below shows the results of measuring the dimensions of the second through holes formed in each example.

[0162] In Example 22, the taper angle θ of the second through hole ａｖｅis 4.9°, and the bulge B ｍａｘ Therefore, it is understood that in Sample 22, the second through hole has a relatively large tapered shape and the non-straight portion is also noticeable.

[0163] In contrast, in Examples 1 and 2, the Δφ of the second through hole is 3.1 μm or less, and the taper angle θ ａｖｅ is 3.8° or less, and the bulge B ｍａｘ It was found that the thickness was suppressed to 3.6 μm or less.

[0164] Therefore, in Samples 1 and 2, the second through holes have a shape that is close to a straight shape with a less tapered shape.

[0165] (Measurement of Surface Roughness of Side Wall of Through Hole) Using Sample 1 and Sample 23, the surface roughness (maximum height Rz) of the side wall of the second through hole was measured.

[0166] For the measurement, a laser microscope (VK-X1000; manufactured by Keyence Corporation) was used.

[0167] Specifically, the surface roughness of the sidewall of the second through-hole was measured at positions 20 μm, 60 μm, 100 μm, 140 μm, 180 μm, and 200 μm deep from the first post-processing opening, with the measurement area being a 5 μm range along the horizontal direction of the sidewall.

[0168] Furthermore, the results obtained for each of the three second through holes were averaged to determine the average value of the maximum height Rz at each depth position.

[0169] 18 shows the relationship between the depth position and the surface roughness obtained for Sample 1. Also, FIG. 19 shows the relationship between the depth position and the surface roughness obtained for Sample 23.

[0170] It can be seen from FIG. 19 that in Sample 23, no difference in surface roughness is observed depending on the depth direction of the second through holes.

[0171] In contrast, it can be seen from FIG. 18 that in Sample 1, the surface roughness changes linearly along the depth direction of the second through-hole.

[0172] In FIG. 18, when the distance in the depth direction is x (μm) and the surface roughness of the inner wall is Q (μm), the relationship between Q and x is approximated by the following equation: Q = mx + b (1), and the slope m is -0.0019.

[0173] 20 and 21 show examples of cross-sectional photographs of the second through holes in Sample 1 and Sample 23, respectively, taken with a laser microscope.

[0174] As described above, in one embodiment of the present invention, it was found that the second through holes have a characteristic shape in which the surface roughness changes along the depth direction.

[0175] (Aspects of the Present Invention) The present invention has the following aspects.

[0176] (Aspect 1) A method for manufacturing a glass substrate with a through hole, the method comprising: (1) irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through hole, the initial through hole having a first initial opening in the first surface and a second initial opening in the second surface; (2) performing a first wet etching on the glass substrate at a first etching rate in a state where a masking material is placed so as to cover an initial opening having a larger diameter out of the first initial opening and the second initial opening of the initial through hole, the first etching rate being in a range of 0.04 μm / min to 0.20 μm / min, thereby forming a first through hole from the initial through hole; and (3) performing a second wet etching on the glass substrate in a state where the masking material is removed, thereby forming a second through hole from the first through hole.

[0177] (Aspect 2) The laser light is CO ２ 2. The method of claim 1, wherein the light is a laser.

[0178] (Aspect 3) The method according to aspect 1 or 2, further comprising: (4) a step of annealing the glass substrate between the step (1) and the step (2).

[0179] (Aspect 4) The method according to any one of aspects 1 to 3, wherein the etching rate during the second wet etching is between 0.07 μm / min and 2 μm / min.

[0180] (Aspect 5) The method according to any one of aspects 1 to 4, wherein the etching solution used in the first wet etching is the same as or different from the etching solution used in the second wet etching.

[0181] (Aspect 6) The second through hole has a first post-processing opening on the first surface of the glass substrate and a second post-processing opening on the second surface of the glass substrate, and the diameter φ of the first post-processing opening is ｆ１ and the diameter φ of the second processed opening ｆ２ Aspect 6. The method of any one of aspects 1 to 5, wherein the difference Δφ (absolute value) between the

[0182] (Aspect 7) In the second through hole, a position where a dimension of a cross section perpendicular to the extension axis of the second through hole is smallest is called a narrowed portion, and in a cross section along the extension axis of the second through hole, one end of the first post-processing opening is defined as a first end P １Ａ and the other end is the second end P １Ｂ The first end P of the second processed opening １Ａ The end on the same side as the third end P ２Ａ and the second end P of the second processed opening １Ｂ The end on the same side as ２Ｂ and the first end P of the narrowed portion １Ａ The end on the same side as the fifth end P ｍＡ and the second end P of the narrowed portion １Ｂ The end on the same side as the sixth end P ｍＢ and the first end P １Ａ and the fifth end P ｍＡ The line segment connecting １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment connecting １Ｂ and the third end P ２Ａ and the fifth end PｍＡ The line segment connecting ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment connecting ２Ｂ and the first end P １Ａ A perpendicular line is drawn from the line segment L １Ａ The angle between the first and second taper angles θ １ｆｕ and the second end P １Ｂ A perpendicular line is drawn from the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ and the third end P ２Ａ A perpendicular line is drawn from the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ and the fourth end P ２Ｂ A perpendicular line is drawn from the line segment L ２Ｂ The angle between the first and second taper angles is defined as the second downward taper angle θ ２ｆｄ and the θ １ｆｕ , θ ２ｆｕ , θ １ｆｄ , and θ ２ｆｄ The average of the taper angle θ ａｖｅ When the taper angle θ is ａｖｅ 7. The method of any one of aspects 1 to 6, wherein the angle .theta. is less than 4 degrees.

[0183] (Aspect 8) In the cross section along the extension axis of the second through hole, １Ａ and the fifth end P ｍＡ The side wall portion between the second end P １Ｂ and the sixth end P ｍＢ The side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ The side wall portion between the first side wall and the line segment L is defined as a fourth side wall. １Ａ The maximum distance between the two points is B.１ and the second side wall and the line segment L １Ｂ The maximum distance between the two points is B. ２ and the third side wall and the line segment L ２Ａ The maximum distance between the two points is B. ３ and the fourth side wall and the line segment L ２Ｂ The maximum distance between the two points is B. ４ and the bulge B １ ~B ４ The largest value among B ｍａｘ When called, the maximum bulge B ｍａｘ 8. The method of claim 7, wherein the thickness is 5 μm or less.

[0184] 9. The method of claim 1, wherein the glass substrate has a thickness in the range of 0.05 mm to 1.2 mm.

[0185] (Aspect 10) A glass substrate with a through hole, comprising: a glass substrate having a first surface and a second surface facing each other; and at least one through hole penetrating the glass substrate from the first surface to the second surface, wherein the glass substrate has a thickness in the range of 0.05 mm to 1.2 mm, and the through hole has a diameter φ １ and a first opening of diameter φ ２ a second opening having a diameter φ of the first opening; １ and the diameter φ of the second opening ２ The absolute value of the difference Δφ is 5 μm or less, and the position in the through hole where the dimension of the cross section perpendicular to the extension axis of the through hole is smallest is called a narrowed portion, and in the cross section along the extension axis of the through hole, one end of the first opening is called a first end P １Ａ and the other end is the second end P １Ｂ and the first end P of the second opening １Ａ The end on the same side as the third end P ２Ａ and the second end P of the second opening １Ｂ The end on the same side as ２Ｂ and the first end P of the narrowed portion １Ａ The end on the same side as the fifth end PｍＡ and the second end P of the narrowed portion １Ｂ The end on the same side as the sixth end P ｍＢ and the first end P １Ａ and the fifth end P ｍＡ The line segment connecting １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment connecting １Ｂ and the third end P ２Ａ and the fifth end P ｍＡ The line segment connecting ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment connecting ２Ｂ and the first end P １Ａ A perpendicular line is drawn from the line segment L １Ａ The angle between the first and second taper angles θ １ｆｕ and the second end P １Ｂ A perpendicular line is drawn from the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ and the third end P ２Ａ A perpendicular line is drawn from the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ and the fourth end P ２Ｂ A perpendicular line is drawn from the line segment L ２Ｂ The angle between the first and second taper angles is defined as the second downward taper angle θ ２ｆｄ and the θ １ｆｕ , θ ２ｆｕ , θ １ｆｄ , and θ ２ｆｄ The average of the taper angle θ ａｖｅ When the taper angle θ is ａｖｅ is less than 4°, and in the cross section along the extension axis of the through hole, the first end P １Ａ and the fifth end P ｍＡ The side wall portion between the second end P １Ｂ and the sixth end P ｍＢThe side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ The side wall portion between the first side wall and the line segment L is defined as a fourth side wall. １Ａ The maximum distance between the two points is B. １ and the second side wall and the line segment L １Ｂ The maximum distance between the two points is B. ２ and the third side wall and the line segment L ２Ａ The maximum distance between the two points is B. ３ and the fourth side wall and the line segment L ２Ｂ The maximum distance between the two points is B. ４ and the bulge B １ ~B ４ The largest value among B ｍａｘ When called, the maximum bulge B ｍａｘ is 5 μm or less, and when a distance of the through hole from the first opening in a depth direction is x (μm) and a surface roughness (maximum height Rz) of a side wall of the through hole is Q (μm), the relationship between Q and x can be approximated by the following equation: Q=mx+b (1), where a slope m is in the range of: (a) -0.001 to -0.005, or (b) 0.001 to 0.005.

[0186] This application claims priority based on Japanese Patent Application No. 2023-128955, filed on August 8, 2023, the entire contents of which are incorporated herein by reference.

[0187] DESCRIPTION OF SYMBOLS 110 Glass substrate 112 First surface 114 Second surface 120 Initial through hole 122 First initial opening 124 Second initial opening 130 Masking material 140 First through hole 142 First opening 144 Second opening 150 Second through hole 152 First post-processing opening 154 Second post-processing opening 210 Glass substrate 212 First surface 214 Second surface 250 Post-processing through hole 252 First post-processing opening 254 Second post-processing opening 260 Narrowed portion 263a First side wall 263b Second side wall 263c Third side wall 263d Fourth side wall 300 Glass substrate with through hole 310 Glass substrate 312 First surface 314 Second surface 350 Through hole 352 First opening 354 Second opening 360 Narrowed portion 363 Side wall L １Ａ , L １Ｂ , L ２Ａ , L ２Ｂ Line segment P １Ａ First end P １Ｂ Second end P ２Ａ Third end P ２Ｂ Fourth end P ｍＡ Fifth end P ｍＢ Sixth End

Claims

1. A method for manufacturing a glass substrate with a through hole, comprising: (1) a step of irradiating a glass substrate having a first surface and a second surface with laser light from the first surface side to form an initial through hole, the initial through hole having a first initial opening on the first surface and a second initial opening on the second surface; (2) a step of performing a first wet etching on the glass substrate at a first etching rate in a state in which a masking material is placed so as to cover an initial opening having a larger diameter out of the first and second initial openings of the initial through hole, the first etching rate being in a range of 0.04 μm / min to 0.20 μm / min, thereby forming a first through hole from the initial through hole; and (3) a step of performing a second wet etching on the glass substrate in a state in which the masking material is removed, thereby forming a second through hole from the first through hole.

2. The laser light is CO ２ The method of claim 1 , wherein the light is a laser light.

3. The method according to claim 2, further comprising: (4) a step of annealing said glass substrate between said steps (1) and (2).

4. The method of claim 2, wherein the etch rate during said second wet etch is between 0.07 μm / min and 2 μm / min.

5. The method of claim 2, wherein the etchant used in the first wet etch is the same as or different from the etchant used in the second wet etch.

6. The second through hole has a first post-processing opening on the first surface of the glass substrate and a second post-processing opening on the second surface of the glass substrate, and the diameter φ of the first post-processing opening is ｆ１ and the diameter φ of the second post-machining opening ｆ２ The method according to claim 2 , wherein the difference Δφ (absolute value) is 5 μm or less.

7. In the second through hole, the position where the dimension of the cross section perpendicular to the extension axis of the second through hole is the smallest is called a narrowed portion, and in the cross section along the extension axis of the second through hole, one end of the first post-machining opening is a first end P １Ａ and the other end is the second end P １Ｂ The first end P of the second processed opening １Ａ The end on the same side as the third end P ２Ａ and the second end P of the second processed opening １Ｂ The end on the same side as the fourth end P ２Ｂ and the first end P of the narrowed portion １Ａ The end on the same side as the fifth end P ｍＡ and the second end P of the narrowed portion １Ｂ The end on the same side as the sixth end P ｍＢ The first end P １Ａ and the fifth end P ｍＡ The line segment connecting １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment connecting １Ｂ and the third end P ２Ａ and the fifth end P ｍＡ The line segment connecting ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment connecting ２Ｂ The first end P １Ａ A perpendicular line is drawn from the line segment L １Ａ The angle between the first upper taper angle θ １ｆｕ The second end P １Ｂ A perpendicular line is drawn from the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ The third end P ２Ａ A perpendicular line is drawn from the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ The fourth end P ２Ｂ A perpendicular line is drawn from the line segment L ２Ｂ The angle between the first and second taper angles θ ２ｆｄ And, the θ １ｆｕ , θ ２ｆｕ , θ １ｆｄ , and θ ２ｆｄ The average of the taper angle θ ａｖｅ When the taper angle θ is ａｖｅ The method of claim 6, wherein is less than 4°.

8. In the cross section along the extension axis of the second through hole, the first end P １Ａ and the fifth end P ｍＡ The side wall portion between the second end P １Ｂ and the sixth end P ｍＢ The side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ A side wall portion between the first side wall and the line segment L is defined as a fourth side wall. １Ａ The maximum distance between the bulge and B １ and the second side wall and the line segment L １Ｂ The maximum distance between the bulge and B ２ and the third side wall and the line segment L ２Ａ The maximum distance between the bulge and B ３ and the fourth side wall and the line segment L ２Ｂ The maximum distance between the bulge and B ４ The bulge B １ ~B ４ The maximum value among B ｍａｘ When it is called, the maximum bulge B ｍａｘ The method of claim 7, wherein the thickness is 5 μm or less.

9. The method of claim 1 or 2, wherein the glass substrate has a thickness in the range of 0.05 mm to 1.2 mm.

10. A glass substrate with a through hole, comprising: a glass substrate having a first surface and a second surface opposed to each other; and at least one through hole penetrating from the first surface to the second surface of the glass substrate, the glass substrate having a thickness in the range of 0.05 mm to 1.2 mm, and the through hole having a diameter φ １ and a first opening having a diameter φ ２ and a second opening having a diameter φ of the first opening. １ and the diameter φ of the second opening ２ The absolute value of the difference Δφ between the first opening and the second opening is 5 μm or less, and the position where the dimension of the cross section perpendicular to the extension axis of the through hole is the smallest is called a narrowed portion, and in the cross section along the extension axis of the through hole, one end of the first opening is a first end P １Ａ and the other end is the second end P １Ｂ and the first end P of the second opening １Ａ The end on the same side as the third end P ２Ａ and the second end P of the second opening １Ｂ The end on the same side as the fourth end P ２Ｂ and the first end P of the narrowed portion １Ａ The end on the same side as the fifth end P ｍＡ and the second end P of the narrowed portion １Ｂ The end on the same side as the sixth end P ｍＢ The first end P １Ａ and the fifth end P ｍＡ The line segment connecting １Ａ and the second end P １Ｂ and the sixth end P ｍＢ The line segment connecting １Ｂ and the third end P ２Ａ and the fifth end P ｍＡ The line segment connecting ２Ａ and the fourth end P ２Ｂ and the sixth end P ｍＢ The line segment connecting ２Ｂ The first end P １Ａ A perpendicular line is drawn from the line segment L １Ａ The angle between the first upper taper angle θ １ｆｕ and the second end P １Ｂ A perpendicular line is drawn from the line segment L １Ｂ The angle between the first and second upper taper angles θ ２ｆｕ and the third end P ２Ａ A perpendicular line is drawn from the line segment L ２Ａ The angle between the first and second taper angles θ １ｆｄ and the fourth end P ２Ｂ A perpendicular line is drawn from the line segment L ２Ｂ The angle between the first and second taper angles θ ２ｆｄ And, the θ １ｆｕ , θ ２ｆｕ , θ １ｆｄ , and θ ２ｆｄ The average of the taper angle θ ａｖｅ When the taper angle θ is ａｖｅ is less than 4°, and in the cross section along the extension axis of the through hole, the first end P １Ａ and the fifth end P ｍＡ The side wall portion between the second end P １Ｂ and the sixth end P ｍＢ The side wall portion between the third end P ２Ａ and the fifth end P ｍＡ The side wall portion between the fourth end P ２Ｂ and the sixth end P ｍＢ A side wall portion between the first side wall and the line segment L is defined as a fourth side wall. １Ａ The maximum distance between the bulge and B １ and the second side wall and the line segment L １Ｂ The maximum distance between the bulge and B ２ and the third side wall and the line segment L ２Ａ The maximum distance between the bulge and B ３ and the fourth side wall and the line segment L ２Ｂ The maximum distance between the bulge and B ４ The bulge B １ ~B ４ The maximum value among B ｍａｘ When it is called, the maximum bulge B ｍａｘ is 5 μm or less, and when a distance in a depth direction of the through hole from the first opening is x (μm) and a surface roughness (maximum height Rz) of a side wall of the through hole is Q (μm), a relationship between Q and x can be approximated by the following equation: Q = mx + b (1), where a slope m is in the range of: (a) -0.001 to -0.005, or (b) 0.001 to 0.005.

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