JP2013010673A - Method for manufacturing glass substrates - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing glass substrates such that it is possible to obtain multiple glass substrates stably from a large glass matrix on which a strong strengthening treatment has been performed.SOLUTION: A method for manufacturing glass substrates comprises a first chemical polishing step and a second chemical polishing step. In the first chemical polishing step, a chemical polishing treatment is performed on only the first major surface of a glass matrix 10 by a predetermined amount of single-side polishing. In the second chemical polishing step, a chemical polishing treatment is performed on each of the first major surface and the second major surface. Subsequently, first partitioning grooves 102 formed in the first major surface and second partitioning grooves 104 formed in the second major surface are connected to each other at a position shifted from the center line 110 in the thickness direction of the glass matrix 10 by an amount of shift 114 which corresponds to the amount of single-side polishing.

Description

  The present invention relates to a glass base material that has been subjected to a tempering treatment, wherein a resist layer is formed on the first main surface and the second main surface so as to straddle a partition line that is a position to be cut. It is related with the manufacturing method of the glass substrate which obtains a some glass substrate by cut-separating by a chemical polishing process.

  A glass substrate is often used for a cover glass or a touch panel applied to a screen of a display device such as a mobile phone because of its transparency. Such a glass substrate is required to be thin from the viewpoint of improving the portability of the apparatus, but is required to have high strength from the viewpoint of safety and the like. For this reason, conventionally, attempts have been made to use tempered glass that has been tempered by a wind-cooling tempering method, a chemical tempering method, or the like for a glass substrate. In particular, chemical strengthening treatment has been widely used for glass substrates for display devices that are required to be thin.

切断等の加工ができない場合には、大型の強化処理済みガラス母材からガラス基板を複数枚採りをすることができなくなるため、単個のガラス基板に対して化学強化処理やチップ領域形成処理等を行うことが余儀なくされる。このため、強化ガラスを用いたガラス基板の生産性の向上を図ることができず、ガラス基板の生産コストが増大するという問題があった。 However, tempered glass subjected to a tempering treatment such as a chemical tempering treatment tends to be difficult to process such as cutting. Generally, when σ _c is a compressive stress [MPa], DOL is a thickness of a chemically strengthened layer [μm], T is a plate thickness [μm], and σ _T is a CT value (Calculated Tensile Stress) [MPa]. Furthermore, it is said that processing such as cutting of chemically strengthened glass becomes more difficult as the CT value, which is the value of σ _T calculated by the following equation, increases.

When processing such as cutting is not possible, it is not possible to take multiple glass substrates from a large tempered glass base material, so chemical strengthening processing or chip area formation processing etc. for a single glass substrate Will be forced to do. For this reason, the improvement of the productivity of the glass substrate using tempered glass cannot be aimed at, but there existed a problem that the production cost of a glass substrate increased.

Therefore, in the prior art, the thickness of the compressive stress layer (corresponding to the DOL) is 10 μm or more and 30 μm or less, and the value of the compressive stress (corresponding to the σ _c ) is 30 kgf / mm ² or more and 60 kgf / mm ² or less. There exists a chemically strengthened glass whose cutting property is improved by setting it to (294 MPa or more and 588 MPa or less) (for example, see Patent Document 1). According to this technology, it is said that the chemically tempered glass that satisfies the market needs can be stably cut.

JP 2004-83378 A

  However, the technique according to Patent Document 1 described above has a disadvantage that only the thickness of the compressive stress layer (chemical strengthening layer) and the value of the compressive stress can be cut. Actually, if the above CT value is about 15, it can be cut, but if the CT value becomes about 20, there are cases where it cannot be divided along the scribe line, or if the cutting pressure is increased, the glass is broken. An inconvenience has occurred. On the other hand, since there is a market need for a thinner and stronger glass substrate, it can be said that there is a demand for a technique that can stably cut even a CT value exceeding 20.

  An object of the present invention is to provide a method for producing a glass substrate capable of stably collecting a plurality of glass substrates from a large glass base material subjected to a strong strengthening treatment.

The method for producing a glass substrate according to the present invention is a glass base material that has been subjected to a tempering treatment, and the resist layer has a first main surface and a second main surface so as to straddle a partition line that is a position to be cut. A plurality of glass substrates are obtained by cutting and separating the glass base material formed by the chemical polishing process. Here, the main surface means two planes on the front side and the back side excluding the four end surfaces of the six surrounding surfaces of the glass base material. The glass substrate manufacturing method includes a first chemical polishing step and a second chemical polishing step. In the first chemical polishing step, a chemical polishing process is performed only on the first main surface of the glass base material by a predetermined single-side polishing amount. In the second chemical polishing step, chemical polishing is performed on both the first main surface and the second main surface.
Before or after performing the second chemical polishing treatment, by performing the first chemical polishing treatment, the first partition groove formed on the first main surface and the second partition formed on the second main surface The partition groove penetrates at a position shifted from the center in the thickness direction of the glass base material by an amount corresponding to the single-side polishing amount.
The first chemical polishing process (single-sided chemical polishing process) and the second chemical polishing process (double-sided chemical polishing process) may be performed in this order, or the same effects can be obtained even when the order is changed. can do.

Usually, when the CT value described above exceeds about 20, it becomes difficult to cut the glass base material by a physical method such as a scribe break method, and it is generated by etching even when it is cut by chemical polishing treatment. There is a tendency that the glass substrate breaks simultaneously with the penetration of the partition groove. However, as described above, by passing through the first partition groove and the second partition groove at a position shifted from the center in the thickness direction of the glass base material by an amount corresponding to the single-side polishing amount, simultaneously with the penetration. Changes in internal stress generated in the glass substrate are reduced, and the glass substrate can be prevented from cracking.
Moreover, after the 1st division groove and the 2nd division groove penetrate, it is preferable to perform the end surface process which further deform | transforms the end surface of a glass substrate into a cross-sectional arc shape. By performing this end surface treatment, it is expected that the deviation from the center in the thickness direction of the protruding portion of the end surface of the glass substrate is corrected and the appearance and strength are improved. Here, the circular arc shape does not mean only a part of a circle whose curvature radii completely coincide with each other, and a plurality of different arcs are continuous within a range where the curvature radii are about ± 5% of each other. Including various shapes.

  According to the present invention, it is possible to stably take a plurality of glass substrates from a large glass base material that has been subjected to a strong strengthening treatment.

It is a figure which shows the outline of the glass base material with which the manufacturing method of the glass substrate which concerns on embodiment of this invention is given. It is a figure which shows the state which set the glass base material vertically to the glass support. It is a figure explaining the state in which a partition groove | channel is formed in a glass base material by a chemical polishing process. It is a figure which shows the state which set the glass base material horizontally on the glass support. It is a figure which shows the state of the glass member of the state which the partition groove penetrated. It is a figure which shows the state which performs a chemical polishing process with respect to the end surface of a glass substrate. It is a figure which shows other embodiment of this invention. It is a figure which shows the other example of the glass base material to which this invention is applied.

  1 (A) and 1 (B) show an outline of a glass base material 10 to which the manufacturing method according to the present invention is applied. The glass base material 10 is, for example, a glass made of aluminosilicate glass having an area of about 400 × 500 mm and reduced in thickness to about 0.5 mm to 1.2 mm (in this embodiment, about 0.7 mm). A base material 10 is used. The glass base material 10 is chemically strengthened in, for example, a potassium nitrate molten salt at about 350 to 450 ° C. After the glass base material 10 is subjected to the chemical strengthening treatment, a plurality of chip regions (use regions) having sensor elements for a touch panel and an overcoat layer for protecting the chip regions are formed on the first main surface side, Thereafter, an acid-resistant resist layer 14 is further formed on the first main surface and the second main surface.

  The resist layer 14 is formed so as to straddle a partition region having a line width of about 1 mm to 5 mm for partitioning the chip region. Various resists resistant to hydrofluoric acid used for the resist layer 14 can be used. For example, OPT (registered trademark) manufactured by Nippon Paint Co., Ltd. is used in this embodiment. On the second main surface of the glass base material 10, an acid resistant film 12 is further stuck on the resist layer 14.

  The acid resistant film 12 is usually attached to the side opposite to the surface on which the chip region is formed. The reason is to improve the peelability of the resist layer 14 on the chip region side. Moreover, it is preferable to affix the acid resistant film 12 between the glass base material 10 so that air may not mix. In this embodiment, the acid resistant film 12 is attached using a glass laminator, but the present invention is not limited to this. Here, as the acid-resistant film 12, a resin film made of PET (polyethylene terephthalate) having a thickness of about 70 μm is used, but a film made of other materials can also be used. 1A shows the glass base material 10 before the acid resistant film 12 is pasted, and FIG. 1B shows the glass base material with the acid resistant film 12 pasted on the second main surface. 10 is shown.

  The glass base material 10 to which the acid resistant film 12 is attached is set in the glass support 16 before chemical polishing treatment. The glass support 16 is made of a material having hydrofluoric acid resistance such as polyvinyl chloride. Further, the glass support 16 includes a plurality of guide grooves configured to support the end portion of the glass base material 10, and is configured so that the glass base material 10 can be inserted along the guide grooves from the opening surface. ing. When the plurality of glass base materials 10 are inserted into the glass support 16 along the guide grooves, the glass support 16 is in a state in which the plurality of glass base materials 10 are spaced from each other and are standing vertically. Will be placed inside. When the chemical polishing process is performed on the glass base material 10, the glass support 16 containing the glass base material 10 is immersed in the chemical polishing tank.

  Then, the chemical polishing process with respect to the glass base material 10 is demonstrated using FIG. 3 (A)-FIG. 3 (B). A chemical polishing liquid containing 2 to 10% by weight of hydrofluoric acid, 2 to 6% by weight of sulfuric acid and 5 to 20% by weight of hydrochloric acid is used. When the glass base material 10 is immersed in the chemical polishing liquid, as shown in FIG. 3A, the portion of the first main surface of the glass base material 10 where the resist layer 14 is not provided is etched, and the first section is etched. A groove 102 is formed. On the other hand, since the acid resistant film 12 is stuck on the second main surface of the glass base material 10, the second main surface is not etched.

  Subsequently, when the first partition groove 102 is deepened by a desired amount, the glass support 16 is taken out from the chemical polishing tank, and the acid resistant film 12 is peeled from the glass base material 10. The glass base material 10 from which the acid-resistant film 12 has been peeled is set again on the glass support 16 and returned to the chemical polishing tank. The single-side polishing amount for single-side chemical polishing of only the first main surface is set by the CT value of the glass base material 10. In principle, the single-side polishing amount needs to be increased as the CT value increases, but it is preferable to make it as small as possible in consideration of the convenience of post-processing and the like. In this embodiment, single-side polishing of about 50 μm is applied to chemically strengthened glass having a CT value of about 25.

  Thereafter, as shown in FIG. 3B, the first partition groove 102 is further deepened on the first main surface of the glass base material 10, while the resist layer 14 on the second main surface of the glass base material 10. The portion not provided with the etching is etched, and the second partition groove 104 is formed. Further, when the chemical polishing process is continued, as shown in FIG. 3C, the first partition groove 102 and the second partition groove 104 are further deepened. When the thickness of the portion of the glass base material 10 where the resist layer 14 is not provided is about 0.1 mm, the glass support 16 is removed from the chemical polishing tank.

  Subsequently, the glass base material 10 is horizontally placed on the glass support 18 with the first main surface facing up. Another glass support 18 (not shown) is placed on the glass base material 10 as necessary. And the glass support 18 which supported the glass base material 10 is immersed in a chemical polishing tank. When the glass base material 10 is immersed in the chemical polishing tank, the first partition groove 102 and the second partition groove 104 are further deepened as shown in FIG. 102 and the second partition groove 104 pass therethrough. By passing through the first partition groove 102 and the second partition groove 104, the glass base material 10 is cut, and a plurality of glass substrates 100 as shown in FIGS. 4B and 5B are obtained.

  Normally, when chemically tempered glass having a CT value exceeding about 20 is cut by etching, the glass substrate 100 breaks simultaneously with the penetration of the partition grooves. However, as in this embodiment, first-side polishing is performed to prevent the glass substrate 100 from being broken simultaneously with the penetration of the partition grooves.

  The details of the mechanism that prevents the glass substrate 100 from being broken simultaneously with the penetration of the partition groove are unknown, but as a result of numerous experiments, the mechanism is assumed to be as follows. That is, normally, when the first main surface and the second main surface of the glass base material 10 are simultaneously etched, the partition groove penetrates on the center line 110 shown in FIG. Located on line 110. Here, in the chemically strengthened glass, a compressive stress layer is formed on the surface, while a tensile stress layer is formed on the back surface, and the tensile stress is considered to be strongest on the center line 110. When the partition groove penetrates at the place where the tensile stress becomes strongest, it is expected that the change in internal stress generated simultaneously with the penetration becomes enormous and the glass substrate is broken.

  For this reason, in the embodiment of the present invention, in order to generate the ridgeline 112 of the glass substrate at a position shifted by a predetermined shift amount 114 from the center line 110 where the tensile stress is strongest, the above-described single-side polishing process is adopted. Yes. As a general rule, it has become clear from experiments that the above-described deviation amount 114 needs to be set larger as the CT value increases. The reason is considered to be that the tensile stress inside the glass base material 10 decreases as the shift amount 114 increases and moves away from the center line. On the other hand, when the amount of deviation 114 is increased more than necessary, the strength and design may be lowered. Therefore, the amount of deviation 114 is as much as possible within a range in which the occurrence of cracks in the glass substrate 100 can be prevented. It can be said that it is preferable to set a small value.

  For example, if the thickness of the glass base material 10 is about 0.5 mm to 1.2 mm and the CT value is up to about 30, the deviation 114 is set to 50 μm to 100 μm to prevent the glass substrate 100 from cracking. Is done. For example, in order to set the deviation amount 114 to 50 μm, the single-side chemical polishing process is performed for about 20 minutes at an etching rate of about 2 to 3 μm / minute, and then the partition groove is formed at an etching rate of about 4 to 6 μm / minute. It is preferable to perform double-sided chemical polishing until it penetrates. In this embodiment, the single-side polishing rate is set to 2.5 μm / min and the double-side polishing rate is set to 5 μm / min. However, the polishing rate can be increased or decreased as necessary.

  Then, the end surface process applied to the end surface of each glass substrate 100 is demonstrated using FIG. 6 (A)-FIG. 6 (B). As shown in FIG. 6A, the end surface of the glass substrate 100 is sharpened at the position of the ridgeline 112 when the partitioning groove penetrates. For this reason, it is preferable to perform the end surface treatment so that the end surface of the glass substrate 100 has an arc shape in a cross-sectional view even after the partitioning grooves penetrate and a plurality of glass substrates 100 are obtained.

  When the end surface treatment is performed on the glass substrate 100, the glass substrate 100 is immersed in the chemical polishing tank for about 1 to 10 hours with the glass support 18 supporting the upper and lower surfaces of the plurality of glass substrates 100. . At this time, it is preferable that the side to be etched more (in this embodiment, the second main surface side) is on the upper side. The reason is that the upper surface is less likely to retain sludge and the like, and a fresher chemical polishing liquid is more easily circulated, so that the polishing rate tends to be higher than the lower surface. As shown in FIG. 6A, the amount of polishing on the second main surface side is larger than that on the first main surface side, so that the first main surface side and the second main surface side are balanced. become. In this embodiment, the first main surface side and the second main surface side are balanced by performing the end surface processing with the side to be etched more upward, but the end surface processing method is the same. It is not limited. For example, the same effect can be obtained by providing a difference in the circulation rate of the etchant up and down, or providing a difference in the viscosity of the etchant up and down.

The glass substrate 100 after the end face treatment is immersed in a peeling tank containing an alkaline peeling solution such as caustic soda or a mixed solution of TMAH (tetramethylammonium hydroxide) and DMI (1,3-dimethyl-2-imidazolidinone). Then, as shown in FIG. 6C, the resist 14 is peeled off. By performing the above processing, a plurality of glass substrates can be stably and efficiently obtained from the chemically strengthened glass base material. In this embodiment, the example in which the end surface treatment is performed before the resist layer 14 is peeled has been described, but it is not always necessary to perform the end surface treatment. If there is no practical problem even if the ridgeline 112 formed on the end surface of the glass substrate 100 is displaced from the center in the thickness direction, the glass substrate 100 can be used without performing the end surface treatment.
In the above-described embodiment, the example in which the double-sided chemical polishing process is performed after the single-sided chemical polishing process is performed first is described. However, the same effect can be obtained by performing the single-sided chemical polishing process after performing the double-sided chemical polishing process. In order to perform, it is possible to change the order of processing as necessary.

  Next, variations of the single-side polishing process will be described with reference to FIGS. 7A and 7B. In the above-described embodiment, the chemical polishing treatment is performed for a predetermined time in a state where the acid-resistant film 12 is attached to the second main surface of the glass base material 10, thereby preventing the partition groove from penetrating at the center in the thickness direction. ing. The technique for preventing the partition groove from penetrating at the center in the thickness direction can also be achieved by a method other than applying the acid-resistant film 12 described above.

  7A and 7B, the glass base material 10 is transported by the transport roller 36 and the chemical polishing process is performed by the upper shower nozzle 34 and the lower shower nozzle 32 disposed above and below the transport roller 36. A single wafer chemical polishing apparatus 30 is provided. In the polishing apparatus 30, as shown in FIG. 7A, the single-sided chemical polishing process is performed only for a predetermined time while spraying the etching solution only from the lower shower nozzle 34, and the polishing apparatus 30 is used with the acid-resistant film 12 described above. Thus, it is possible to obtain the same effect as that of the single-side polishing process. At this time, after performing the single-sided chemical polishing process as shown in FIG. 7A, the process may be shifted to the double-sided chemical polishing process as shown in FIG. 7B, or as shown in FIG. 7A. After the single-side chemical polishing treatment, the immersion treatment in the chemical polishing liquid tank described above may be performed. Moreover, you may make it convey, supporting the glass base material 10 using the above-mentioned glass support tool 18 as needed. Furthermore, it is also possible to change the order of the single-sided chemical polishing treatment and the double-sided chemical polishing treatment.

  Moreover, although the above-mentioned embodiment demonstrated the example which cut | disconnects the large sized glass base material 10 and obtains several rectangular glass substrates, the shape of the glass substrate 100 is limited to a rectangle as shown to FIG. 8 (A). Not. The shape of the glass substrate can be made into an arbitrary shape by appropriately changing the shape of the partition region formed in the resist layer 14 by a photolithography technique. When the glass base material is cut by the chemical polishing process, as shown in FIG. 8 (B), there is no problem even in a complicated shape in which a plurality of arcs having a small curvature radius are continuous, and in the vicinity of the end portion. There is no problem even if the shape is such that the through hole 152 is provided.

  The glass substrate 100 obtained by the above-described manufacturing method can be used as a user-side glass substrate constituting a touch panel integrated liquid crystal display. It can also be used as a cover glass for a liquid crystal display of a mobile phone.

  Since the sensor element provided in the chip region is generally vulnerable to heat, it has been difficult to perform chemical strengthening treatment on the glass in which the chip region is formed. According to the embodiment of the present invention, the chip region is formed. Since it is possible to stably cut the chemically strengthened large glass base material 10 to obtain a plurality of glass substrates 100, productivity is remarkably improved particularly in a glass substrate on which a sensor element for a touch panel is mounted. It becomes possible to make it.

  The above description of the embodiment is to be considered in all respects as illustrative and not restrictive. The scope of the present invention is shown not by the above embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications within the meaning and scope equivalent to the scope of the claims.

10-glass base material 12-acid resistant film 14-resist layer 16-glass support 18-glass support 100-glass substrate 102-first partition groove 104-second partition groove

Claims (2)

A glass base material that has been subjected to a tempering treatment, and a glass base material in which a resist layer is formed on the first main surface and the second main surface so as to straddle a partition line that is a position to be cut. A glass substrate manufacturing method for obtaining a plurality of glass substrates by cutting and separating by:
A first chemical polishing step in which only a predetermined amount of single-side polishing is applied to only the first main surface;
A second chemical polishing step of subjecting both the first main surface and the second main surface to a chemical polishing treatment;
Including
The first partition groove formed on the first main surface and the second partition groove formed on the second main surface are shifted by an amount corresponding to the single-side polishing amount from the center in the thickness direction of the glass base material. A method for producing a glass substrate, wherein the glass substrate is penetrated at a different position.   2. The method according to claim 1, further comprising an end surface processing step of performing an end surface processing for deforming the end surface of the glass substrate into an arc shape in a sectional view after the first partition groove and the second partition groove have penetrated. The manufacturing method of the glass substrate of description.

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