Method of manufacturing glass plates

Abstract

To increase an inclination angle of an inner wall surface of a through hole.SOLUTION: A method for manufacturing a glass plate includes: a modification step S1 of modifying a formation scheduled part 3 of a through hole 9 by irradiation with a laser beam L; and an etching step S2 of immersing a glass plate 2 in an etching liquid 6 and etching a first main surface 2a and a second main surface 2b after the modification step S1, and thereby forming the through hole 9 in the formation scheduled part 3. The etching step S2 includes: a first etching step S2a of etching the glass plate 2 through which the formation scheduled part 3 does not penetrate; and a second etching step S2b of etching the glass plate 2 through which the formation scheduled part 3 penetrates after the first etching step S2a. Average relative speed of the etching liquid 6 to the glass plate 2 in the second etching step S2b is higher than that in the first etching step S2a.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a glass plate having through holes.

Background Art

[0002] For example, as substrates such as a tiling display (micro LED, etc.), a borderless display, and a glass interposer, a glass plate having fine through holes for wiring (through electrodes, etc.) is used.

[0003] As a method for manufacturing this type of glass plate having through holes, for example, a modification step of modifying a planned formation position of a through hole in a glass plate by irradiating laser light to form a modified portion, and an etching step of etching a planned formation portion including the modified portion to form a through hole (see, for example, Patent Documents 1 and 2).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the above manufacturing method, since the modified portion formed in the modification step has a larger etching rate than the unmodified portion, it is selectively removed in the etching step. Therefore, by forming the modified portion from the first main surface to the second main surface along the plate thickness direction of the glass plate, a through hole can be formed by etching.

[0006] When through-holes are formed in this way, the portion of the glass plate closer to the main surface is more easily etched due to prolonged contact with the etching solution. As a result, the diameter of the through-hole becomes larger in the portion closer to the main surface than in the center in the thickness direction of the plate, and the inner wall surface of the through-hole becomes tapered. When the diameter of the holes on the main surface of the glass plate becomes large in this way, problems may arise, such as the inability to form high-resolution patterns on the main surface of the glass plate.

[0007] The inclination angle of the inner wall surface of the through hole with respect to the direction perpendicular to the plate thickness direction (the angle made between the direction perpendicular to the plate thickness direction and the inner wall surface of the through hole; hereinafter simply referred to as the "inclination angle of the inner wall surface") changes depending on the etching conditions.

[0008] The present invention aims to increase the inclination angle of the inner wall surface of a through hole. [Means for solving the problem]

[0009] (1) The present invention, devised to solve the above problems, is a method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, comprising a modification step of modifying the portion to be formed of the through hole by irradiation with laser light, and an etching step after the modification step of forming a through hole in the portion to be formed by immersing the glass plate in an etching solution and etching it, wherein the etching step comprises a first etching step of etching the glass plate in which the portion to be formed has not been penetrated, and a second etching step performed after the first etching step of etching the glass plate in which the portion to be formed has been penetrated, characterized in 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.

[0010] As a result of diligent research, the inventors have found that the inclination angle of the inner wall surface of the final through-hole is determined by (a) the magnitude of the inclination angle of the inner wall surface of the planned part when the planned part penetrates, and (b) the rate of change of the inclination angle of the inner wall surface of the planned part after the planned part penetrates. In other words, in order to increase the inclination angle of the final through-hole, it is important to (a') increase the inclination angle of the inner wall surface of the planned part when the planned part penetrates (approaching 90°) and (b') change the rate of change of the inclination angle of the inner wall surface of the planned part after the planned part penetrates in the positive direction.

[0011] The area to be formed, modified by laser irradiation, is in a state where it is easily etched. However, when the area to be formed is not penetrated, that is, when the area to be formed is a bottomed recess, the etching solution cannot move through the inside of the area in the thickness direction of the plate. Therefore, even if the average relative velocity of the etching solution to the glass plate is increased in this state, the efficiency of etching solution exchange within the recess of the area to be formed does not increase compared to the efficiency of etching solution exchange on the main surface of the glass plate. In other words, even if the average relative velocity of the etching solution is increased, the time required for etching solution exchange does not decrease within the recess of the area to be formed compared to the main surface of the glass plate. As a result, etching is only promoted near the main surface of the glass plate, and the pore diameter on the main surface preferentially expands. This reduces the inclination angle of the inner wall surface of the area to be formed when it is penetrated. On the other hand, when the area to be formed is penetrated, the etching solution can move through the inside of the area in the thickness direction of the plate. Therefore, if the average relative velocity of the etching solution to the glass plate is increased in this state, the efficiency of etching solution exchange within the area to be formed will increase, similar to the efficiency of etching solution exchange on the main surface of the glass plate. As a result, the rate of change in the inclination angle of the inner wall surface of the area to be formed after penetration can be changed in the positive direction. Thus, as in the above configuration, if the average relative velocity of the etching solution to the glass plate is increased in the second etching step compared to the first etching step, the inclination angle of the inner wall surface of the area to be formed when it is penetrated can be increased, and the rate of change in the inclination angle of the inner wall surface of the area to be formed after penetration can be changed in the positive direction. This makes it possible to increase the inclination angle of the inner wall surface of the through hole.

[0012] (2) In the configuration of (1) above, it is preferable that the second etching process is started when the part to be formed has been penetrated.

[0013] In this way, the etching rate within the target area can be increased from the moment the target area is penetrated. Therefore, the rate of change in the inclination angle of the inner wall surface of the target area after penetration can be changed more positively. This makes it possible to increase the inclination angle of the inner wall surface of the through hole.

[0014] (3) In the configuration of (1) or (2) above, the etching solution may be stirred in the etching step, and the average stirring speed of the etching solution may be faster in the second etching step than in the first etching step.

[0015] In this way, the average relative rate of the etching solution to the glass plate can be made faster in the second etching step than in the first etching step.

[0016] (4) In the configurations of (1) to (3) above, in the etching process, the glass plate is moved in the etching solution, and the average moving speed of the glass plate may be faster in the second etching process than in the first etching process.

[0017] In this way, the average relative rate of the etching solution to the glass plate can be made faster in the second etching step than in the first etching step.

[0018] (5) The present invention, devised to solve the above problems, is a method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, comprising a modification step of modifying the area to be formed of the through hole by irradiation with laser light, and an etching step after the modification step of forming a through hole in the area to be formed by spraying an etching solution onto the first main surface and the second main surface and etching, wherein the etching step comprises a first etching step of etching the glass plate in which the area to be formed has not been penetrated, and a second etching step performed after the first etching step of etching the glass plate in which the area to be formed has been penetrated, characterized in that the average spray pressure of the etching solution onto the glass plate is higher in the second etching step than in the first etching step.

[0019] By doing so, for the same reasons as described above, if the average injection pressure of the etching solution onto the glass plate by injection is increased in the second etching step more than in the first etching step, the inclination angle of the inner wall surface of the planned formation portion when the planned formation portion penetrates can be increased, and the rate of change of the inclination angle of the inner wall surface of the planned formation portion after the planned formation portion penetrates can be changed in the positive direction. As a result, the inclination angle of the inner wall surface of the through-hole can be increased.

[0020] (6) In the configuration of (5) above, it is preferable that the second etching step is started when the planned formation portion penetrates.

[0021] By doing so, the inclination angle of the inner wall surface of the through-hole can be more reliably increased.

Effect of the Invention

[0022] According to the present invention, the inclination angle of the inner wall surface of the through-hole can be increased.

Brief Description of the Drawings

[0023] [Figure 1] It is a flowchart showing a method for manufacturing a glass plate according to the first embodiment. [Figure 2] It is a cross-sectional view showing a modification step included in the method for manufacturing a glass plate according to the first embodiment. [Figure 3] It is a cross-sectional view showing the first etching step included in the method for manufacturing a glass plate according to the first embodiment. [Figure 4] It is a cross-sectional view showing the second etching step included in the method for manufacturing a glass plate according to the first embodiment. [Figure 5] It is a cross-sectional view of the glass plate in the first etching step included in the method for manufacturing a glass plate according to the first embodiment. [Figure 6] It is a cross-sectional view of the glass plate in the second etching step included in the method for manufacturing a glass plate according to the first embodiment, showing the state when the planned formation portion of the glass plate penetrates. [ [Figure 7]This is a cross-sectional view of a glass plate having through holes, manufactured by the glass plate manufacturing method according to the first embodiment. [Figure 8] This is a cross-sectional view showing the first etching step and the second etching step included in the manufacturing method of a glass plate according to the second embodiment. [Figure 9] This is a side view showing the first etching step included in the manufacturing method of a glass plate according to the third embodiment. [Figure 10] This is a side view showing the second etching step included in the manufacturing method of the glass plate according to the third embodiment. [Figure 11] This is a side view showing the first etching step and the second etching step included in the manufacturing method of a glass plate according to the fourth embodiment. [Figure 12] This graph shows the relationship between the taper angle of the area to be formed and the etching time before penetration of the area to be formed. [Figure 13] This graph shows the relationship between the etching rate of the main surface and the stirring speed before penetration of the area to be formed. [Figure 14] This graph shows the relationship between the etching rate of the area to be formed and the stirring speed before penetration of the area to be formed. [Figure 15] This graph shows the relationship between the taper angle of the planned formation area and the stirring speed when the area is penetrated. [Figure 16] This graph shows the relationship between the rate of change in the taper angle of the target area after penetration and the stirring speed. [Modes for carrying out the invention]

[0024] Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In each embodiment, corresponding components will be denoted by the same reference numerals, and redundant explanations may be omitted. If only a part of the configuration is described in each embodiment, the configuration of other embodiments described earlier can be applied to the other parts of that configuration. Not only are the combinations of configurations explicitly stated in the description of each embodiment possible, but configurations from multiple embodiments can also be partially combined, even if not explicitly stated, as long as there are no particular problems with the combination.

[0025] (First Embodiment) As shown in Figure 1, the method for manufacturing a glass plate according to the first embodiment comprises, in this order, a modification step S1 and an etching step S2 including a first etching step S2a and a second etching step S2b.

[0026] As shown in Figure 2, modification step S1 is a step in which the portion 3 in the glass plate 2 where through holes are to be formed is modified by laser light L irradiated from the laser device 1. The modified portion 3 includes a modified portion 4 that extends in the thickness direction of the plate. The modified portion 4 has the property of being easily etched and has a higher etching rate than the unmodified portion. It is preferable that the modified portion 4 is formed continuously in the thickness direction of the plate, but it may also be formed intermittently in the thickness direction of the plate. When multiple through holes are formed in the glass plate 2, multiple portions 3 including the modified portion 4 are also formed.

[0027] The type and irradiation conditions of the laser beam L are not particularly limited, as long as it can form a modified portion 4 in the area 3 where the through-hole is to be formed in the glass plate 2. In this embodiment, the laser beam L is a short-pulse laser beam (picosecond laser beam, nanosecond laser beam, femtosecond laser beam). The diameter W of the modified portion 4 can be adjusted by the spot diameter of the laser beam L, etc.

[0028] As shown in Figures 3 and 4, etching step S2 is a process in which the glass plate 2 is etched to form through holes in the planned formation area 3, which includes the modified area 4, that penetrate between the first main surface 2a and the second main surface 2b of the glass plate 2 in the thickness direction. In etching step S2, the glass plate 2 is immersed in the etching solution 6 stored in the etching container 5, and etching is carried out simultaneously from both sides of the first main surface 2a and the second main surface 2b of the glass plate 2.

[0029] In detail, etching step S2 comprises a first etching step S2a (see Figure 3) for etching the glass plate 2 that is not penetrated by the portion to be formed 3, and a second etching step S2b (see Figure 4) performed after the first etching step S2a for etching the glass plate 2 that is penetrated by the portion to be formed 3. The same etching container 5 containing the etching solution 6 is used in both the first etching step S2a and the second etching step S2b. Note that the etching container used in the first etching step S2a may be different from the etching container used in the second etching step S2b.

[0030] The average relative velocity V2 of the etching solution 6 to the glass plate 2 in the second etching process S2b (hereinafter referred to as the second average relative velocity) is faster than the average relative velocity V1 of the etching solution 6 to the glass plate 2 in the first etching process S2a (hereinafter referred to as the first average relative velocity).

[0031] Methods for making the second mean relative velocity V2 faster than the first mean relative velocity V1 include, for example, stirring the etching solution 6 or moving the glass plate 2 in the etching solution 6. Furthermore, to make the second mean relative velocity V2 faster than the first mean relative velocity V1, the stirring of the etching solution 6 and the moving of the glass plate 2 in the etching solution 6 may be used in combination.

[0032] Methods for stirring the etching solution 6 include, for example, oscillating a louver or vibrating the etching solution 6 with ultrasonic waves. In this embodiment, however, a method of rotating a stirring member (including screw rotation) 7 is employed. In the illustrated example, 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 may be positioned below the glass plate 2 or above the glass plate. When stirring the etching solution 6, in order to make the second mean relative velocity V2 faster than the first mean relative velocity V1, it is preferable to make the average stirring speed of the etching solution 6 in the second etching step S2b (referred to as the second mean stirring speed) faster than the average stirring speed of the etching solution 6 in the first etching step S2a (referred to as the first mean stirring speed). Here, the average stirring speed refers to the average rotational speed of the stirring member 7 when the stirring member 7 is used. The position of the stirring member 7 is not particularly limited.

[0033] 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 or rotating the glass plate 2 in the etching solution 6. When moving the glass plate 2 in the etching solution 6, 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) in order to make the second average relative velocity V2 faster than the first average relative velocity V1.

[0034] The second etching process S2b is started when the area to be formed 3 penetrates in the thickness direction of the plate. In other words, when the area to be formed 3 penetrates in the thickness direction of the plate, the average relative velocity of the etching solution 6 with respect to the glass plate 2 is switched from the first average relative velocity V1 to the second average relative velocity V2.

[0035] In this embodiment, the etching time required to penetrate the target area 3 under the same etching conditions is measured in advance. When this measured time has elapsed, it is assumed that the target area 3 has been penetrated, and the second etching process S2b is started. Alternatively, the moment when the target area 3 is penetrated may be observed in real time using a camera or the like, and the second etching process S2b may be started when the penetration of the target area 3 is observed.

[0036] The reason for making the second average relative velocity V2 of the second etching process S2b faster than the first average relative velocity V1 of the first etching process S2a is as follows. In Figures 5 to 7, the symbols 2aо and 2bо indicate the positions of the main surfaces 2a and 2b before etching.

[0037] As shown in Figure 5, in the first etching step S2a, the planned formation portion 3, including the modified portion 4, is gradually removed by etching. However, in the first etching step S2a, the planned formation portion 3 is not penetrated, but forms a bottomed recess 8. In this state, the etching solution 6 cannot move through the inside of the planned formation portion 3 in the thickness direction of the plate. Therefore, even if the first average relative velocity V1 is increased, the exchange efficiency of the etching solution 6 within the recess 8 of the planned formation portion 3 does not increase. When the exchange efficiency of the etching solution 6 is poor in this way, the etching solution 6 within the recess 8 of the planned formation portion 3 is gradually contaminated by reaction products (sludge). Therefore, when the etching rate of the planned formation portion 3 is R1 and the etching rates of the main surfaces 2a and 2b are R2, the ratio of R1 / R2 decreases. As a result, etching is only promoted near the main surfaces 2a and 2b of the glass plate 2, and the inclination angle (also called the taper angle) θ1 (see Figure 6) of the inner wall surface 3a of the planned formation portion 3 at the time of penetration becomes smaller.

[0038] On the other hand, as shown in Figure 6, in the second etching step S2b, the area to be formed 3 is penetrated. In this state, the etching solution 6 can freely move within the area to be formed 3 in the thickness direction. Therefore, increasing the second average relative velocity V2 increases the exchange efficiency of the etching solution 6 inside the area to be formed 3, 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, etching of the area to be formed 3 is also promoted, similar to etching near the main surfaces 2a and 2b of the glass plate 2. This makes it possible to reduce the change in the inclination angle θ1 of the inner wall surface 3a of the area to be formed 3 after penetration, while shortening the etching time until the desired hole diameter is achieved.

[0039] For these reasons, the second average relative velocity V2 in the second etching process S2b is set to be faster than the first average relative velocity V1 in the first etching process S2a. By doing so, (1) the inclination angle θ1 of the inner wall surface 3a of the planned formation part 3 when it penetrates is increased, and (2) the rate of change of the inclination angle θ1 of the inner wall surface 3a of the planned formation part 3 after it has penetrated is changed in the positive direction. As a result, as shown in Figure 7, the inclination angle (also called the taper angle) θ2 of the inner wall surface 9a of the through hole 9 that is finally formed in the glass plate 2 can be increased.

[0040] The hole diameter at the center of the through hole 9 in the thickness direction is the minimum hole diameter D1, and the hole diameter at the main surfaces 2a and 2b of the through hole 9 is the maximum hole diameter D2.

[0041] (Second embodiment) As shown in Figure 8, the difference between the glass plate manufacturing method according to the second embodiment and the glass plate manufacturing method according to the first embodiment is that in the etching step S2, the glass plate 2 immersed in the etching solution 6 is transported.

[0042] In this embodiment, the etching solution 6 is stored in an etching container 10 that is long in the direction of transport of the glass plate 2. The glass plate 2 is transported by a transport device 11 such as rollers while immersed in the etching solution 6. In the transport path of the glass plate 2, the first etching process S2a is performed in the first area 12 upstream in the transport direction from the position through which the planned formation portion 3 penetrates, and the second etching process S2b is performed in the second area 13, which includes the position through which the planned formation portion 3 penetrates and the downstream side in the transport direction thereof. In other words, the average relative velocity of the etching solution 6 with respect to the glass plate 2 is set to a relatively small first average relative velocity V1 in the first area 12, and to a relatively large second average relative velocity V2 in the second area 13.

[0043] In this case, the average stirring speed of the stirring member 7b in the second area 13 may be faster than the average stirring speed of the stirring member 7a in the first area 12. Also, the average moving speed of the glass plate 2 by the conveying device 11 in the second area 13 may be faster than the average moving speed of the glass plate 2 by the conveying device 11 in the first area 12. In addition, other methods described in the first embodiment can also be applied to adjust the average relative speed of the etching solution 6 to the glass plate 2 in each area 12 and 13.

[0044] In this embodiment, a partition wall 14 is provided between the first area 12 and the second area 13 to suppress the movement of the etching solution 6 between the two areas. In this way, since each area 12 and 13 is separated by the partition wall 14, it becomes easier to individually adjust the average relative velocity of the etching solution 6 with respect to the glass plate 2 in each area 12 and 13. Note that the partition wall 14 may be omitted.

[0045] (Third embodiment) As shown in Figures 9 and 10, the difference between the glass plate manufacturing method according to the third embodiment and the glass plate manufacturing methods according to the first and second embodiments is that in the etching step S2, instead of immersing the glass plate 2 in the etching solution 6, the etching solution 6 is sprayed onto the first main surface 2a and the second main surface 2b of the glass plate 2.

[0046] In this embodiment, the etching process S2 includes a first etching process S2a (see Figure 9) in which etching solution 6 is sprayed from a nozzle 15 onto the first main surface 2a and the second main surface 2b of the glass plate 2 that are not penetrated by the portion to be formed 3, and a second etching process S2b (see Figure 10) which is performed after the first etching process S2a in which etching solution 6 is sprayed from a nozzle 15 onto the first main surface 2a and the second main surface 2b of the glass plate 2 that are penetrated by the portion to be formed 3.

[0047] The average injection pressure Q2 of the etching solution 6 onto the glass plate 2 in the second etching process S2b (hereinafter referred to as the second average injection pressure) is higher than the average injection pressure Q1 of the etching solution 6 onto the glass plate 2 in the first etching process S2a (hereinafter referred to as the first average injection pressure).

[0048] The second etching process S2b is started when the area to be formed 3 penetrates in the thickness direction of the plate. In other words, when the area to be formed 3 penetrates in the thickness direction of the plate, the average injection pressure of the etching solution 6 against the glass plate 2 is switched from the first average injection pressure Q1 to the second average injection pressure Q2.

[0049] (Fourth embodiment) As shown in Figure 11, the difference between the glass plate manufacturing method according to the fourth embodiment and the glass plate manufacturing method according to the third embodiment is that in the etching step S2, the etching solution 6 is sprayed onto the glass plate 2 being transported.

[0050] In this embodiment, the glass plate 2 is transported downstream in the transport direction by the transport device 16. Along the transport 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, respectively. Along the transport path of the glass plate 2, the first etching process S2a is performed in the first area 17 upstream of the position where the planned formation portion 3 penetrates, and the second etching process S2b is performed in the second area 18, which includes the position where the planned formation portion 3 penetrates and the area downstream thereof. In other words, the average spray pressure of the etching solution 6 onto the glass plate 2 is set to a relatively low first average spray pressure Q1 in the first area 17, and to a relatively high second average spray pressure Q2 in the second area 18.

[0051] In this case, the amount of etching solution 6 sprayed per unit time from the nozzle 15b in the second area 18 may be greater than the amount of etching solution 6 sprayed per unit time from the nozzle 15a in the first area 17. Alternatively, the number of nozzles 15b in the second area 18 may be relatively increased compared to the number of nozzles 15a in the first area 17.

[0052] Furthermore, the present invention is not limited to the configuration of the above embodiments, nor is it limited to the effects described above. The present invention can be modified in various ways without departing from the spirit of the invention.

[0053] The second etching step S2b may be started before the penetration of the planned portion 3 (for example, a few minutes before penetration). Alternatively, the second etching step S2b may be started after the penetration of the planned portion 3 (for example, a few minutes after penetration). In other words, the starting timing of the second etching step S2b is not particularly limited, as long as it includes a step of etching the glass plate 2 through which the planned portion 3 has penetrated. However, from the viewpoint of maximizing the inclination angle θ2 of the inner wall surface 9a of the final through hole 9, it is preferable that the second etching step S2b be started when the planned portion 3 has penetrated.

[0054] In etching step S2, the glass plates 2 may be etched one by one, or multiple glass plates 2 may be etched simultaneously. Furthermore, when etching while transporting the glass plates 2 in etching step S2, the transport path of the glass plates 2 is not limited to a straight line, but may be curved, such as a circular or annular shape. [Examples]

[0055] The present invention will be described in detail below based on examples, but the present invention is not limited to these examples.

[0056] First, we measured how the inclination angle (taper angle) of the inner wall surface of the through-hole ultimately formed in the glass plate changes with etching time. The results are shown in Figure 12.

[0057] The point indicated by the symbol P in the figure represents the taper angle of the target area when the target area penetrates through. This taper angle at the time of penetration changes according to the rate of change of the taper angle (in the example shown, -0.07° / min) and the etching time until the through hole is finally formed. In other words, the taper angle of the through hole is determined by (1) the taper angle of the target area when the target area penetrates through, (2) the rate of change of the taper angle of the target area after the target area penetrates through, and (3) the etching time.

[0058] Next, we evaluated how the average relative velocity of the etching solution to the glass plate affected the taper angle of the through-holes formed in the glass plate. The results are shown in Figures 13 to 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 stirring bar and stir liquids such as etching solutions.

[0059] As shown in Figure 13, before the area to be formed is penetrated, the etching rate of the main surface of the glass plate increases as the stirring speed of the etching solution increases. In contrast, as shown in Figure 14, before the area to be formed is penetrated, the etching rate of the area to be formed remains almost unchanged even if the stirring speed of the etching solution increases. Also, as shown in Figure 15, the taper angle of the area to be formed when it is penetrated decreases as the stirring speed of the etching solution increases. From these results, it can be seen that if the stirring speed of the etching solution is increased before the area to be formed is penetrated, etching is promoted only near the main surface of the glass plate, and the taper angle of the area to be formed when it is penetrated decreases. Therefore, it is preferable to slow down the average relative velocity of the etching solution to the glass plate before the area to be formed is penetrated.

[0060] As shown in Figure 16, the rate of change in the taper angle of the target area after penetration changes in the positive direction as the stirring speed of the etching solution increases. From this result, it can be seen that increasing the stirring speed of the etching solution after penetration can change the angle change of the target area from the taper angle at the time of penetration in the positive direction. Therefore, it is preferable to increase the average relative speed of the etching solution to the glass plate after penetration of the target area.

[0061] From the above, it can be seen that by slowing down the average relative rate of the etching solution to the glass plate before the area to be formed is penetrated, and then increasing the average relative rate of the etching solution to the glass plate after the area to be formed is penetrated, the taper angle of the final through-hole can be increased. [Explanation of symbols]

[0062] 1. Laser device 2 glass plates 2a First principal surface 2b Second principal surface 3. Planned Formation 3a Inner wall surface 4. Modification section 5 Etching container 6 Etching solution 7. Stirring member 8 recesses 9 Through hole 10 Etching containers 11. Conveying device 12 First Area 13 Second Area 14 Partition Wall 15 nozzles 16 Conveying device 17 First Area 18 Second Area L Laser light S1 Modification Process S2 Etching process S2a First Etching Process S2b Second Etching Process θ1 Inclination angle (taper angle) of the inner wall surface of the area to be formed θ2 Inclination angle (taper angle) of the inner wall surface of the through hole

Claims

1. A method for manufacturing a glass plate having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, A modification step in which the portion where the through hole is to be formed is modified by irradiation with laser light, The process includes, after the modification step, an etching step in which the glass plate is immersed in an etching solution and etched to form the through-hole in the area to be formed, The etching process includes a first etching step of etching the glass plate in which the portion to be formed does not penetrate, and a second etching step performed after the first etching step of etching the glass plate in which the portion to be formed penetrates. The average relative rate of the etching solution to the glass plate is made faster in the second etching step than in the first etching step. A method for manufacturing a glass plate, characterized in that the same etching container in which the etching solution is stored is used in the first etching step and the second etching step.

2. The method for manufacturing a glass plate according to claim 1, wherein the second etching step is started when the portion to be formed is penetrated.

3. In the etching step, the etching solution is stirred, The method for manufacturing a glass plate according to claim 1 or 2, wherein the average stirring speed of the etching solution is faster in the second etching step than in the first etching step.

4. In the etching process, the glass plate is moved in the etching solution. A method for manufacturing a glass plate according to any one of claims 1 to 3, wherein 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 having a first main surface, a second main surface, and a through hole penetrating between the first main surface and the second main surface, A modification step in which the portion where the through hole is to be formed is modified by irradiation with laser light, The process includes, after the modification step, an etching step in which an etching solution is sprayed onto the first main surface and the second main surface to etch them, thereby forming the through-holes in the area to be formed, The etching process comprises a first etching step of etching the glass plate in which the portion to be formed has not been penetrated, and a second etching step performed after the first etching step of etching the glass plate in which the portion to be formed has been penetrated. The average injection pressure of the etching solution onto the glass plate is increased in the second etching step compared to the first etching step. A method for manufacturing a glass plate, characterized in that the etching solution is sprayed from the same nozzle in the first etching step and the second etching step.

6. The method for manufacturing a glass plate according to claim 5, wherein the second etching step is started when the portion to be formed is penetrated.

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