Manufacturing method of glass plate

Abstract

The present invention includes: a modification step S1, wherein the predetermined portion 3 for forming a through hole 9 is modified by irradiation with laser light L; and an etching step S2, wherein, after the modification step S1, a glass plate 2 is immersed in an etching solution 6 to etch the first main surface 2a and the second main surface 2b, thereby forming the through hole 9 in the predetermined portion 3. The etching step S2 includes: a first etching step S2a, which etches the glass plate 2 in which the predetermined portion 3 is not formed; and a second etching step S2b, performed after the first etching step S2a, which etches the glass plate 2 in which the predetermined portion 3 is formed. The average relative velocity of the etching solution 6 to the glass plate 2 is faster in the second etching step S2b than in the first etching step S2a.

Description

Technical Field

[0001] This invention relates to a method for manufacturing a glass plate having a through hole. Prior Technology

[0002] For example, as a substrate for tiling displays (such as miniature light-emitting diodes, LEDs), bezel-less displays, and glass interposers, a glass plate with micro-through holes for wiring (such as through electrodes) is used.

[0003] A method for manufacturing a glass plate having such a through hole may include, for example, a modification step in which a predetermined location for forming the through hole in the glass plate is modified by irradiating with laser light to form a modified portion; and an etching step in which the predetermined location for forming the through hole, including the modified portion, is etched to form the through hole (see, for example, Patent Document 1 and Patent Document 2). [Existing Technical Documents] [Patent Literature]

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-199605 Patent Document 2: Japanese Patent Application Publication No. 2020-66551 Summary of the Invention

[0005] [The problem that the invention aims to solve]

[0006] In the manufacturing method described above, the modified portion formed in the modification step is selectively removed in the etching step because its etching rate is greater than that of the unmodified portion. Therefore, by forming the modified portion along the thickness direction of the glass plate from the first main surface to the second main surface, a through hole can be formed by etching.

[0007] In the case of a through-hole, the portion closer to the main surface of the glass plate is more easily etched due to prolonged contact with the etching solution. Regarding the diameter of the through-hole, the portion closer to the main surface is larger than the central portion in the thickness direction, and the inner wall of the through-hole becomes conical. If the diameter of the through-hole on the main surface of the glass plate becomes larger, it may lead to defects such as the inability to form highly detailed patterns on the main surface of the glass plate.

[0008] The inclination angle of the inner wall surface of the through hole relative to the direction orthogonal to the plate thickness direction (the angle between the direction orthogonal to the plate thickness direction and the inner wall surface of the through hole, hereinafter referred to as the "inclination angle of the inner wall surface") varies depending on the etching conditions.

[0009] The objective of this invention is to increase the inclination angle of the inner wall surface of the through hole. [Methods for solving problems]

[0010] (1) The present invention, created to solve the aforementioned problem, is a method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface. The method for manufacturing the glass plate is characterized by comprising: a modification step, wherein a predetermined portion for forming the through hole is modified by irradiating with laser light; and an etching step, wherein after the modification step, the glass plate is immersed in an etching solution for etching, thereby forming the through hole in the predetermined portion. The etching step comprises: a first etching step, wherein the glass plate in which the predetermined portion is not penetrated is etched; and a second etching step, performed after the first etching step, wherein the glass plate in which the predetermined portion is penetrated is etched, such that the average relative velocity of the etching solution to the glass plate is faster in the second etching step than in the first etching step.

[0011] The inventors conducted extensive research and discovered that the inclination angle of the inner wall surface of the ultimately formed through hole is determined by (a) the magnitude of the inclination angle of the inner wall surface of the formed portion when the predetermined portion penetrates, and (b) the rate of change of the inclination angle of the inner wall surface of the formed portion after the predetermined portion has penetrated. That is, in order to increase the inclination angle of the ultimately formed through hole, it is important to (a') increase the inclination angle of the inner wall surface of the formed portion when the predetermined portion penetrates (to close to 90°) and (b') make the rate of change of the inclination angle of the inner wall surface of the formed portion after the predetermined portion has penetrated change in the positive direction.

[0012] The pre-formed portion modified by laser irradiation is in a state where it is easily etched. However, in the state where the pre-formed portion is not penetrated, i.e., when the pre-formed portion is a recessed portion with a bottom, the etchant cannot travel back and forth along the thickness direction inside the pre-formed portion. Therefore, even if the average relative velocity of the etchant to the glass plate is increased in this state, the exchange efficiency of the etchant in the recess of the pre-formed portion is not improved compared to the etchant exchange efficiency on the main surface of the glass plate. In other words, even if the average relative velocity of the etchant is increased, the time required for etchant exchange is not shorter in the recess of the pre-formed portion compared to the main surface of the glass plate. As a result, etching is promoted only near the main surface of the glass plate, and the aperture of the main surface is preferentially enlarged. As a result, the inclination angle of the inner wall surface of the pre-formed portion when it penetrates is smaller. On the other hand, when the pre-formed portion is penetrated, the etchant can travel back and forth along the thickness direction inside the pre-formed portion. Therefore, if the average relative velocity of the etchant to the glass plate is increased in this state, the exchange efficiency of the etchant inside the pre-formed portion is also increased, just like the etchant exchange efficiency on the main surface of the glass plate. As a result, the rate of change of the inclination angle of the inner wall surface of the formed predetermined portion after penetration can be directed in the positive direction. Therefore, as described in the structure, if the average relative velocity of the etching solution to the glass plate is made faster in the second etching step than in the first etching step, the inclination angle of the inner wall surface of the formed predetermined portion during penetration can be increased, and the rate of change of the inclination angle of the inner wall surface of the formed predetermined portion after penetration can be directed in the positive direction. This increases the inclination angle of the inner wall surface of the through hole.

[0013] (2) In the structure described in (1), it is preferable that the second etching step begins when the predetermined portion has been formed.

[0014] If this is done, the etching speed within the predetermined portion can be increased starting from when the predetermined portion has been penetrated. Therefore, the rate of change of the inclination angle of the inner wall surface of the predetermined portion after penetration can be further positively changed. This allows for an increase in the inclination angle of the inner wall surface of the through hole.

[0015] (3) In the structure of (1) or (2), the etching solution is stirred in the etching step so that the average stirring speed of the etching solution is faster in the second etching step than in the first etching step.

[0016] If so, the average relative velocity of the etching solution to the glass plate can be faster in the second etching step than in the first etching step.

[0017] (4) In the structures described in (1) to (3), the glass plate is moved in the etching solution during the etching step, and the average moving speed of the glass plate is faster in the second etching step than in the first etching step.

[0018] If so, the average relative velocity of the etching solution to the glass plate can be faster in the second etching step than in the first etching step.

[0019] (5) The present invention, created to solve the aforementioned problem, is a method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface. The method for manufacturing the glass plate is characterized by comprising: a modification step, wherein a predetermined portion for forming the through hole is modified by irradiating with laser light; and an etching step, wherein after the modification step, an etching solution is sprayed onto each of the first main surface and the second main surface to etch, thereby forming the through hole in the predetermined portion. The etching step comprises: a first etching step, wherein the glass plate in which the predetermined portion is not penetrated is etched; and a second etching step, performed after the first etching step, wherein the glass plate in which the predetermined portion is penetrated is etched, such that the average spray pressure of the etching solution relative to the glass plate is higher in the second etching step than in the first etching step.

[0020] If so, for the same reasons already stated, if the average spray pressure of the etching solution relative to the glass plate is greater in the second etching step than in the first etching step, the inclination angle of the inner wall surface of the predetermined portion when it penetrates can be increased, and the rate of change of the inclination angle of the inner wall surface of the predetermined portion after penetration can be made to change in the positive direction. This allows for an increase in the inclination angle of the inner wall surface of the through hole.

[0021] (6) In the structure of (5), it is preferable that the second etching step begins when the predetermined portion has been formed.

[0022] If so, the inclination angle of the inner wall surface of the through hole can be increased more reliably. [The effects of the invention]

[0023] According to the present invention, the inclination angle of the inner wall surface of the through hole can be increased. Simple Explanation of the Diagram

[0024] Figure 1 is a flowchart illustrating a method for manufacturing a glass plate according to the first embodiment. Figure 2 is a cross-sectional view showing the modification step included in the manufacturing method of the glass plate according to the first embodiment. Figure 3 is a cross-sectional view showing the first etching step included in the manufacturing method of the glass plate according to the first embodiment. Figure 4 is a cross-sectional view showing the second etching step included in the manufacturing method of the glass plate according to the first embodiment. Figure 5 is a cross-sectional view of the glass plate in the first etching step included in the glass plate manufacturing method of the first embodiment. Figure 6 is a cross-sectional view of the glass plate in the second etching step included in the glass plate manufacturing method of the first embodiment, showing the state when the glass plate formation predetermined portion penetrates. Figure 7 is a cross-sectional view of a glass plate with a through hole manufactured by the glass plate manufacturing method of the first embodiment. Figure 8 is a cross-sectional view showing the first etching step and the second etching step included in the glass plate manufacturing method of the second embodiment. Figure 9 is a side view showing the first etching step included in the glass plate manufacturing method of the third embodiment. Figure 10 is a side view showing the second etching step included in the glass plate manufacturing method of the third embodiment. Figure 11 is a side view showing the first etching step and the second etching step included in the glass plate manufacturing method of the fourth embodiment. Figure 12 is a graph showing the relationship between the taper angle of the pre-formed portion before it penetrates and the etching time. Figure 13 is a graph showing the relationship between the etching rate and the stirring speed of the main surface before the predetermined part is formed. Figure 14 is a graph showing the relationship between the etching rate and stirring speed of the pre-formed portion before it penetrates the pre-formed portion. Figure 15 is a graph showing the relationship between the cone angle of the pre-formed section and the stirring speed when the pre-formed section is penetrated. Figure 16 is a graph showing the relationship between the rate of change of the cone angle of the pre-formed section after it has been penetrated and the stirring speed. Implementation

[0025] Hereinafter, the forms in which the present invention is implemented will be described with reference to the drawings. Furthermore, corresponding constituent elements in each embodiment are labeled with the same symbols, thereby omitting sometimes repeated descriptions. Where only a part of the structure is described in each embodiment, the structures of other embodiments described earlier can be applied to the other parts of the structure. Not only combinations of structures already explained in the descriptions of each embodiment, but also combinations of structures from multiple embodiments can be partially combined with each other, even if not explicitly stated, as long as such combinations do not pose a particular obstacle.

[0026] (First Implementation) As shown in Figure 1, the glass plate manufacturing method of the first embodiment includes a modification step S1 and an etching step S2 in sequence. The etching step S2 includes a first etching step S2a and a second etching step S2b.

[0027] As shown in Figure 2, the modification step S1 is a step of modifying the predetermined portion 3 for forming through holes in the glass plate 2 by using laser light L irradiated from the laser device 1. The modified predetermined portion 3 includes a modified portion 4 extending along the thickness direction of the plate. The modified portion 4 is easily etched, and the etching rate is greater than that of the unmodified portion. The modified portion 4 is preferably formed continuously in the thickness direction, but it can also be formed intermittently in the thickness direction. When multiple through holes are formed in the glass plate 2, multiple predetermined portions 3 including the modified portion 4 are also formed.

[0028] The type and irradiation conditions of the laser light L are not particularly limited as long as the modified part 4 can be formed in the predetermined part 3 of the through hole in the glass plate 2. In this embodiment, the laser light L is a short-pulse laser light (picosecond laser light, nanosecond laser light, femtosecond laser light). The diameter W of the modified part 4 can be adjusted by the dot diameter of the laser light L, etc.

[0029] As shown in Figures 3 and 4, etching step S2 is a step of forming a through hole in the pre-formation section 3, including the modified section 4, between the first main surface 2a and the second main surface 2b of the glass plate 2 by etching the glass plate 2. In etching step S2, the glass plate 2 is immersed in the etching solution 6 stored in the etching container 5, so that etching is performed simultaneously from both sides of the first main surface 2a and the second main surface 2b of the glass plate 2.

[0030] In detail, etching step S2 includes: a first etching step S2a, etching the glass plate 2 through which the predetermined portion 3 is not formed (see Figure 3); and a second etching step S2b, performed after the first etching step S2a, etching the glass plate 2 through which the predetermined portion 3 is formed (see Figure 4). In both the first etching step S2a and the second etching step S2b, the same etching container 5 storing the etching solution 6 is used. Furthermore, the etching container used in the first etching step S2a may be different from the etching container used in the second etching step S2b.

[0031] The average relative velocity (hereinafter referred to as the second average relative velocity) V2 of the etchant 6 relative to the glass plate 2 in the second etching step S2b is faster than the average relative velocity (hereinafter referred to as the first average relative velocity) V1 of the etchant 6 relative to the glass plate 2 in the first etching step S2a.

[0032] Methods for making the second average relative velocity V2 faster than the first average relative velocity V1 include, for example, stirring the etching solution 6 and moving the glass plate 2 in the etching solution 6. Furthermore, in order to make the second average relative velocity V2 faster than the first average relative velocity V1, the methods of stirring the etching solution 6 and moving the glass plate 2 in the etching solution 6 can also be used together.

[0033] Methods for stirring the etching solution 6 include, for example, oscillating a louver or vibrating the etching solution 6 using ultrasound. In this embodiment, a method of rotating the stirring member (including a rotating screw) 7 is used. In the example shown, the stirring member 7 is positioned to the side of the glass plate 2, but the position of the stirring member 7 is not particularly limited. The stirring member 7 can be positioned below or above the glass plate 2. When stirring the etching solution 6, in order to make the second average relative velocity V2 faster than the first average relative velocity V1, it is preferable that the average stirring speed of the etching solution 6 in the second etching step S2b (referred to as the second average stirring speed) is faster than the average stirring speed of the etching solution 6 in the first etching step S2a (referred to as the first average stirring speed). Here, the average stirring speed, when using the stirring member 7, refers to the average rotational speed of the stirring member 7. Furthermore, the position of the stirring member 7 is not particularly limited.

[0034] Methods for moving the glass plate 2 in the etching solution 6 include, for example, oscillating the glass plate 2 in the etching solution 6 and rotating the glass plate 2 in the etching solution 6. When moving the glass plate 2 in the etching solution 6, in order to make the second average relative speed V2 faster than the first average relative speed V1, it is preferable to make the average moving speed of the glass plate 2 in the second etching step S2b (referred to as the second average moving speed) faster than the average moving speed of the glass plate 2 in the first etching step S2a (referred to as the first average moving speed).

[0035] The second etching step S2b begins when the predetermined portion 3 has penetrated along the thickness direction of the plate. That is, at the point when the predetermined portion 3 has penetrated along the thickness direction, the average relative velocity of the etching solution 6 relative to the glass plate 2 changes from the first average relative velocity V1 to the second average relative velocity V2.

[0036] In this embodiment, the etching time for the predetermined portion 3 to penetrate under the same etching conditions is predetermined, and the second etching step S2b is started when the predetermined portion 3 is considered to have penetrated after the predetermined time has elapsed. Alternatively, the time for the predetermined portion 3 to penetrate can be observed in real time using a camera or the like, and the second etching step S2b is started when the penetration of the predetermined portion 3 is observed.

[0037] The reason why the second average relative velocity V2 of the second etching step S2b is faster than the first average relative velocity V1 of the first etching step S2a is as follows. Furthermore, in Figures 5 to 7, the symbol 2ao represents the position of the main surface 2a before etching, and the symbol 2bo represents the position of the main surface 2b before etching.

[0038] As shown in Figure 5, in the first etching step S2a, the predetermined forming portion 3, including the modified portion 4, is slowly removed by etching. However, in the first etching step S2a, the predetermined forming portion 3 is not penetrated, forming a recessed portion 8 with a bottom. In this state, the etching solution 6 cannot travel back and forth along the thickness direction inside the predetermined forming portion 3. Therefore, even if the first average relative velocity V1 is increased, the exchange efficiency of the etching solution 6 in the recessed portion 8 of the predetermined forming portion 3 does not improve. If the exchange efficiency of the etching solution 6 is poor, the etching solution 6 in the recessed portion 8 of the predetermined forming portion 3 will be slowly contaminated by reaction products (sludge). Therefore, when the etching rate of the predetermined forming portion 3 is set to R1 and the etching rate of the main surface 2a and the main surface 2b is set to R2, the ratio of R1 / R2 decreases. As a result, etching is only promoted near the main surface 2a and the main surface 2b of the glass plate 2, and the tilt angle (also called the cone angle) θ1 (see Figure 6) of the inner wall surface 3a of the predetermined forming portion 3 when penetrating becomes smaller.

[0039] On the other hand, as shown in FIG6, in the second etching step S2b, the predetermined portion 3 is formed through the entire surface. In this state, the etching solution 6 can freely travel back and forth along the thickness direction inside the predetermined portion 3. Therefore, if the second average relative velocity V2 is increased, the exchange efficiency of the etching solution 6 inside the predetermined portion 3 is also improved, similar to the exchange efficiency of the etching solution 6 on the main surfaces 2a and 2b of the glass plate 2. As a result, the etching of the predetermined portion 3 is also promoted, similar to the etching near the main surfaces 2a and 2b of the glass plate 2. In this way, the change in the tilt angle θ1 of the inner wall surface 3a of the predetermined portion 3 after penetration can be reduced, and the etching time until the desired aperture is achieved is shortened.

[0040] For this reason, the second average relative velocity V2 in the second etching step S2b is made faster than the first average relative velocity V1 in the first etching step S2a. Furthermore, if this is the case, (1) the inclination angle θ1 of the inner wall surface 3a of the predetermined portion 3 when the predetermined portion 3 penetrates can be increased, and (2) the rate of change of the inclination angle θ1 of the inner wall surface 3a of the predetermined portion 3 after the predetermined portion 3 penetrates can be made to change in the positive direction. Therefore, as shown in FIG7, the inclination angle (also called the cone angle) θ2 of the inner wall surface 9a of the through hole 9 finally formed in the glass plate 2 can be increased.

[0041] The diameter of the hole at the center of the through hole 9 in the thickness direction is the minimum diameter D1, and the diameters at the main surfaces 2a and 2b of the through hole 9 are the maximum diameter D2.

[0042] (Second Implementation) As shown in Figure 8, the difference between the glass plate manufacturing method of the second embodiment and the glass plate manufacturing method of the first embodiment is that, in the etching step S2, the glass plate 2 immersed in the etching solution 6 is transported.

[0043] In this embodiment, an etching solution 6 is stored in an elongated etching container 10 along the conveying direction of the glass plate 2. The glass plate 2 is conveyed by a conveying device 11 such as a roller while immersed in the etching solution 6. Along the conveying path of the glass plate 2, a first etching step S2a is performed in a first region 12 upstream of the position through which the predetermined portion 3 is formed, and a second etching step S2b is performed in a second region 13 downstream of the position through which the predetermined portion 3 is formed and the conveying direction of that position. That is, the average relative velocity of the etching solution 6 relative to the glass plate 2 is set to a relatively small first average relative velocity V1 in the first region 12 and a relatively large second average relative velocity V2 in the second region 13.

[0044] In this case, the average stirring speed of the stirring member 7b in the second region 13 can also be faster than the average stirring speed of the stirring member 7a in the first region 12. Furthermore, the average moving speed of the glass plate 2 using the conveying device 11 in the second region 13 can also be faster than the average moving speed of the glass plate 2 using the conveying device 11 in the first region 12. Moreover, other methods described in the first embodiment can also be applied similarly as methods for adjusting the average relative speed of the etching solution 6 with respect to the glass plate 2 in each region 12 and 13.

[0045] In this embodiment, a partition wall 14 is provided between the first region 12 and the second region 13, which inhibits the back-and-forth movement of the etching solution 6 between the two regions. If this is done, each region 12, 13 is divided by the partition wall 14, thus making it easy to adjust the average relative velocity of the etching solution 6 with respect to the glass plate 2 in each region 12, 13. Alternatively, the partition wall 14 can be omitted.

[0046] (Third Implementation) As shown in Figures 9 and 10, the glass plate manufacturing method of the third embodiment differs from that of the glass plate manufacturing methods of the first and second embodiments in that, in the etching step S2, etching solution 6 is sprayed onto the first main surface 2a and the second main surface 2b of the glass plate 2 instead of immersing the glass plate 2 in the etching solution 6.

[0047] In this embodiment, the etching step S2 includes: a first etching step S2a, in which etching liquid 6 is sprayed from the nozzle 15 onto the first main surface 2a and the second main surface 2b of the glass plate 2 through which the predetermined portion 3 is not penetrated, to perform etching (see FIG9); and a second etching step S2b, which is performed after the first etching step S2a, in which etching liquid 6 is sprayed from the nozzle 15 onto the first main surface 2a and the second main surface 2b of the glass plate 2 through which the predetermined portion 3 is penetrated, to perform etching (see FIG10).

[0048] The average spray pressure of the etchant 6 relative to the glass plate 2 in the second etching step S2b (hereinafter referred to as the second average spray pressure) Q2 is higher than the average spray pressure of the etchant 6 relative to the glass plate 2 in the first etching step S2a (hereinafter referred to as the first average spray pressure) Q1.

[0049] The second etching step S2b begins when the predetermined portion 3 has penetrated through the plate thickness direction. That is, when the predetermined portion 3 has penetrated through the plate thickness direction, the average spray pressure of the etching solution 6 relative to the glass plate 2 switches from the first average spray pressure Q1 to the second average spray pressure Q2.

[0050] (Fourth Implementation) As shown in Figure 11, the difference between the glass plate manufacturing method of the fourth embodiment and the glass plate manufacturing method of the third embodiment is that, in the etching step S2, the glass plate 2 being transported is sprayed with etching solution 6.

[0051] In this embodiment, the glass plate 2 is conveyed downstream in the conveying direction by the conveying device 16. Along the conveying path of the glass plate 2, etching solution 6 is sprayed from nozzles 15a and 15b onto the first main surface 2a and the second main surface 2b of the glass plate 2. Along the conveying path of the glass plate 2, a first etching step S2a is performed in a first region 17 upstream of the location where the predetermined portion 3 penetrates, and a second etching step S2b is performed in a second region 18 downstream of the location where the predetermined portion 3 penetrates. That is, the average spray pressure of the etching solution 6 relative to the glass plate 2 is set to a relatively low first average spray pressure Q1 in the first region 17 and a relatively high second average spray pressure Q2 in the second region 18.

[0052] In this case, the amount of etching solution 6 sprayed per unit time from the nozzle 15b in the second region 18 can also be greater than the amount of etching solution 6 sprayed per unit time from the nozzle 15a in the first region 17. In addition, the number of nozzles 15b in the second region 18 can also be relatively increased compared to the number of nozzles 15a in the first region 17.

[0053] Furthermore, the present invention is not limited to the structure of the described embodiments, nor to the described effects. Various modifications can be made to the present invention without departing from its spirit.

[0054] The second etching step S2b may also begin sometime before the penetration of the predetermined portion 3 (e.g., several minutes before penetration). Alternatively, the second etching step S2b may begin sometime after the penetration of the predetermined portion 3 (e.g., several minutes after penetration). That is, as long as the second etching step S2b includes the step of etching the glass plate 2 through which the predetermined portion 3 is formed, the starting time of the second etching step S2b is not particularly limited. However, from the viewpoint of maximizing the inclination angle θ2 of the inner wall surface 9a of the ultimately formed through hole 9, the second etching step S2b is preferably started when the predetermined portion 3 has been formed.

[0055] In etching step S2, glass plates 2 can be etched one by one, or multiple glass plates 2 can be etched simultaneously. In addition, in etching step S2, when etching is performed while the glass plates 2 are being transported, the transport path of the glass plates 2 is not limited to a straight line, but can also be a curved path such as a circle. [Example]

[0056] The present invention will now be described in detail based on the embodiments, but the present invention is not limited to these embodiments.

[0057] First, the tilt angle (cone angle) of the inner wall surface of the through hole ultimately formed in the glass plate was measured to see how it varied with etching time. The measurement results are shown in Figure 12.

[0058] The point indicated by symbol P in the figure is the taper angle of the pre-formed portion when it penetrates the hole. This taper angle varies with the rate of change of the taper angle (-0.07° / min in the example) and the etching time before the final through hole is formed. That is, the taper angle of the through hole is determined by (1) the taper angle of the pre-formed portion when it penetrates the hole, (2) the rate of change of the taper angle of the pre-formed portion after it penetrates the hole, and (3) the etching time.

[0059] Next, we evaluated how the average relative velocity of the etching solution to the glass plate affected the taper angle of the through-hole formed in the glass plate. The evaluation results are shown in Figures 13-16. The average relative velocity of the etching solution to the glass plate was adjusted by stirring the etching solution using a water bath stirrer. A water bath stirrer is a device that uses magnetic force to rotate a stir bar to stir liquids such as etching solutions.

[0060] As shown in Figure 13, before the predetermined portion penetrates, the etching rate of the main surface of the glass plate increases with the increase of the stirring speed of the etching solution. In contrast, as shown in Figure 14, even if the stirring speed of the etching solution increases before the predetermined portion penetrates, the etching rate of the predetermined portion remains almost unchanged. Furthermore, as shown in Figure 15, if the stirring speed of the etching solution is increased, the cone angle of the predetermined portion at the time of penetration decreases. Based on these results, it can be seen that if the stirring speed of the etching solution is increased before the predetermined portion penetrates, etching is only promoted near the main surface of the glass plate, and the cone angle of the predetermined portion at the time of penetration decreases. Therefore, it is preferable to reduce the average relative velocity of the etching solution to the glass plate before the predetermined portion penetrates.

[0061] As shown in Figure 16, the rate of change of the cone angle of the pre-formed portion after penetration changes positively as the stirring speed of the etching solution increases. Based on this result, it can be concluded that increasing the stirring speed of the etching solution after penetration can positively change the angle change from the cone angle of the pre-formed portion at the time of penetration. Therefore, it is preferable to increase the average relative velocity of the etching solution to the glass plate after penetration.

[0062] Based on the above, it can be seen that if the average relative velocity of the etching solution to the glass plate is slowed down before the predetermined penetration is formed, and the average relative velocity of the etching solution to the glass plate is accelerated after the predetermined penetration is formed, the tapered angle of the final through hole can be increased.

[0063] 1: Laser device 2: Glass plate 2a: First primary surface 2ao: Position of the first primary surface before etching 2b: Second primary surface 2bo: Position of the second primary surface before etching 3: Formation of a pre-planned department 3a: Inner wall surface 4: Quality Modification Department 5, 10: Etched containers 6: Etching solution 7, 7a, 7b: Mixing components 8: concave part 9: Through hole 9a: Inner wall surface of the through hole 11, 16: Transport device 12, 17: First Area 13, 18: Second Zone 14: Spacer 15, 15a, 15b: Nozzles D1: Minimum aperture D2: Maximum aperture L: Laser light S1: Modification Steps S2: Etching Step S2a: First etching step S2b: Second etching step W: Diameter θ1: Inclination angle (cone angle) of the inner wall surface forming the predetermined part θ2: Inclination angle (conical angle) of the inner wall surface of the through hole.

Claims

1. A method for manufacturing a glass plate, the glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, the method for manufacturing the glass plate being characterized by comprising: The modification step involves modifying the predetermined portion of the through hole by irradiating it with laser light; The etching step involves immersing the glass plate in an etching solution after the modification step to form the through hole in the predetermined portion. The etching step includes a first etching step, in which the glass plate in which the predetermined portion is not formed is etched. The second etching step, performed after the first etching step, etches the glass plate through which the predetermined portion is formed, such that the average relative velocity of the etching solution with respect to the glass plate is faster in the second etching step than in the first etching step. In both the first and second etching steps, the same etching container storing the etching solution is used.

2. The method of manufacturing a glass plate as claimed in claim 1, wherein the second etching step begins when the predetermined portion has been formed.

3. A method for manufacturing a glass plate as claimed in claim 1 or claim 2, wherein in the etching step, the etching solution is stirred such that the average stirring speed of the etching solution is faster in the second etching step than in the first etching step.

4. A method for manufacturing a glass plate as claimed in claim 1 or claim 2, wherein in the etching step, the glass plate is moved in the etching solution such that the average moving speed of the glass plate is faster in the second etching step than in the first etching step.

5. A method for manufacturing a glass plate, the glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, the method for manufacturing the glass plate being characterized by comprising: The modification step involves modifying the predetermined portion of the through hole by irradiating it with laser light; The etching step includes an etching step in which, after the modification step, etching solution is sprayed onto each of the first main surface and the second main surface to form the through hole in the predetermined part. The etching step includes a first etching step in which the glass plate in which the predetermined part is not penetrated is etched. The second etching step, performed after the first etching step, etches the glass plate through which the predetermined portion is formed, such that the average jet pressure of the etching solution relative to the glass plate is higher in the second etching step than in the first etching step, and the etching solution is jetted from the same nozzle in both the first and second etching steps.

6. A method for manufacturing a glass plate as claimed in claim 5, wherein the second etching step begins when the predetermined portion has been formed.

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