TWI526411B - Method for manufacturing glass substrates - Google Patents

Description

Method for manufacturing glass substrate

The present invention relates to a glass base material to be subjected to a tempering treatment, and is a glass base material in which a resist layer is formed on the first main surface and the second main surface so as to cross over a position to be cut, that is, a region. A method of producing a glass substrate of a plurality of glass substrates by cutting and separating by chemical polishing treatment.

In a cover glass or a touch panel that is applied to a screen of a display device such as a mobile phone, a glass substrate is mostly used based on its transparency. The glass substrate as described above is required to be thinner from the viewpoint of improving the portability of the device, and is required to have high strength from the viewpoint of safety and the like. Therefore, in the past, it has been attempted to use a tempered glass which is subjected to a strengthening treatment by an air-cooling strengthening method or a chemical strengthening method, etc., on a glass substrate. In particular, chemical strengthening treatment is widely used for a glass substrate for a display device which is required to be thin.

However, the strengthened glass which has been subjected to the strengthening treatment such as the chemical strengthening treatment tends to be difficult to perform processing such as cutting. In general, when σ _{c is} a compressive stress [MPa], DOL is a thickness of a chemical strengthening layer [μm], T is a plate thickness [μm], and σ _T is a calculated value (Calculated Tensile Stress). In the case of [MPa], the larger the value of σ _T calculated by the following formula, that is, the larger the CT value, the more difficult it is to cut the chemically strengthened glass.

If it is impossible to perform processing such as cutting, it is impossible to use a plurality of glass substrates for the glass base material after the large-scale strengthening treatment, and therefore it is only necessary to perform chemical strengthening treatment or wafer field formation treatment on a single glass substrate. Therefore, the productivity improvement of the glass substrate using a tempered glass cannot be achieved, and there exists a problem that the production cost of a glass substrate increases.

Therefore, in the prior art, the thickness (corresponding to the above DOL) of the compressive stress layer is set to 10 μm or more and 30 μm or less, and the value of the compressive stress (corresponding to the above σ _c ) is set to 30 kgf/mm ² or more and 60 kgf. / ² or less mm (294MPa 588MPa or more or less) to enhance the cutting power so that the chemical strengthened glass (e.g. refer to Patent Document 1). By this technique, it is possible to stably cut the chemically strengthened glass that satisfies the market demand.

[Previous Technical Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2004-83378

However, in the technique of Patent Document 1, there is a problem that the thickness of the compressive stress layer (chemical strengthening layer) and the value of the compressive stress can be cut within a predetermined range. In fact, if the CT value is about 15, the cutting can be performed. However, if the CT value is about 20, there is a case where the cutting cannot be performed along the cutting line, or if the cutting pressure is increased, the glass may be broken. The bad situation happened. On the other hand, there is a market demand for a thinner and more robust glass substrate. Therefore, it is a technique for stably cutting off a CT value of more than 20.

An object of the present invention is to provide a method for producing a glass substrate which can be stably used in a plurality of glass substrates by a large-sized glass base material which has been subjected to a strengthening and strengthening treatment.

The method for producing a glass substrate according to the present invention is to form a glass base material to be tempered, and to form a resist layer on the first main surface and the second main surface so as to cross the region to be cut, that is, to scribe the region. The glass base material is cut and separated by a chemical polishing treatment, thereby obtaining a plurality of glass substrates. Here, the main surface means two planes of the front side and the back side other than the four end faces of the six sides of the glass base material. The method for producing the glass substrate includes a first chemical polishing step and a second chemical polishing step. In the first chemical polishing step, the chemical polishing treatment is performed only on the first main surface of the glass base material at a predetermined one-side polishing amount. In the second chemical polishing step, chemical polishing treatment is performed on both the first main surface and the second main surface.

The first chemical research is performed before or after the second chemical polishing treatment. The grinding treatment is performed so that the first region groove formed on the first main surface and the second region groove formed on the second main surface are corresponding to the single-side polishing in the center of the thickness direction of the glass base material. The amount of quantity deviates from the position.

The first chemical polishing treatment (single-sided chemical polishing treatment) and the second chemical polishing treatment (double-sided chemical polishing treatment) can be carried out in this order, and the same operational effects can be obtained even if the order is reversed.

In general, when the CT value exceeds about 20, the glass base material is difficult to be cut by a physical method such as a cutting and splitting method, and even in the case of being cut by a chemical polishing treatment, it is also etched by etching. At the same time as the occurrence of the division groove, the glass substrate tends to be broken. However, as described above, the first region groove and the second region groove are penetrated at a position offset by the amount corresponding to the one-side polishing amount from the center in the thickness direction of the glass base material, and the glass is penetrated at the same time. The internal stress change occurring in the substrate is reduced, and the glass substrate is prevented from being broken.

Further, it is preferable that the end surface of the glass substrate is deformed into an end surface which is arcuate in cross section after the first region groove and the second region groove are inserted. By performing the end surface treatment, the center of the thickness direction of the protruding portion of the end surface in the glass substrate is corrected and shifted, and the appearance or strength can be expected to be improved. Here, the arc shape does not mean only a part of a circle in which the radius of curvature completely coincides, but a shape in which a plurality of circular arcs having mutually different curvature radii from each other within a range of about ±5% are continuous.

By means of the invention, it is possible to use a large glass that has been subjected to a strong strengthening treatment The base material is stabilized by a plurality of glass substrates.

Fig. 1 (A) and Fig. 1 (B) show the outline of a glass base material 10 which is subjected to the production method of the present invention. The glass base material 10 has, for example, an area of about 400×500 mm, and a glass base material 10 made of aluminum silicate glass which is thinned to a thickness of about 0.5 mm to 1.2 mm (about 0.7 mm in this embodiment) is used. . The glass base material 10 is chemically strengthened in a molten salt of potassium nitrate of, for example, about 350 to 450 °C. After the chemical strengthening treatment, the glass base material 10 is formed on the first main surface side in the field of a plurality of wafers (using fields) including a sensor element for a touch panel, and a protective layer in the field of protecting wafers. The first main surface and the second main surface are formed with an acid resistant resist layer 14.

The resist layer 14 is formed to span a region of a region having a line width of about 1 mm to 5 mm for arranging the above-mentioned wafer field. The hydrofluoric acid etch resist used in the resist layer 14 can be used in various forms. For example, in the present embodiment, OPTO (registered trademark) manufactured by Nippon Paint Co., Ltd. is used. On the second main surface of the glass base material 10, an acid-resistant film 12 is additionally adhered to the resist layer 14.

The acid-resistant film 12 is usually attached to the opposite side to the surface on which the wafer is formed. The reason for this is to improve the peelability of the resist layer 14 on the wafer field side. Further, the acid-resistant film 12 is preferably adhered so that air does not mix between the glass base material 10 and the glass base material 10. In the present embodiment, the adhesion of the acid-resistant film 12 is performed using a glass laminator, but It is not limited to this. In addition, 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 of another material may be used. In FIG. 1(A), the glass base material 10 before the adhesion of the acid-resistant film 12 is shown, and in FIG. 1(B), the glass base material 10 to which the acid-resistant film 12 is adhered to the second main surface is shown.

The glass base material 10 to which the acid-resistant film 12 is adhered is placed in the glass holder 16 before the chemical polishing treatment. The glass support member 16 is composed of a material having hydrogen fluoride resistance such as polyvinyl chloride. Further, the glass holder 16 is provided with a plurality of guide grooves formed to support the end portions of the glass base material 10, and is configured to be inserted into the glass base material 10 along the guide grooves. When the plurality of glass base materials 10 are inserted into the glass holder 16 along the guide grooves, the plurality of glass base materials 10 are placed in the glass holder 16 in a state in which the plurality of glass base materials 10 are provided with a gap therebetween, and in each of the vertically erected states. . When the glass base material 10 is subjected to a chemical polishing treatment, the glass support member 16 containing the glass base material 10 is immersed in a chemical polishing bath.

Next, the chemical polishing treatment of the glass base material 10 will be described using FIGS. 3(A) to 3(B). For the chemical polishing liquid, those 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 are used. When the glass base material 10 is immersed in the chemical polishing liquid, as shown in FIG. 3(A), the portion of the first main surface of the glass base material 10 where the resist layer 14 is not provided is etched to form the first division groove 102. On the other hand, since the acid-resistant film 12 is adhered to the second main surface of the glass base material 10, the second main surface is not Etched.

Next, at the stage where the first region groove 102 is deepened by a desired amount, the glass holder 16 is taken out from the chemical polishing bath, and the acid-resistant film 12 is peeled off from the glass base material 10. The glass base material 10 from which the acid-resistant film 12 has been peeled off is again placed on the glass holder 16 and returned to the chemical polishing bath. The single-side polishing amount in which only the first main surface is subjected to one-side chemical polishing is set by the CT value of the glass base material 10. In principle, the single-side polishing amount must be increased as the CT value becomes larger, but it is preferable to form as small as possible in consideration of the convenience of post-treatment. In the present embodiment, the chemically strengthened glass having a CT value of about 25 is subjected to single-side polishing of about 50 μm.

Then, as shown in FIG. 3(B), the first partition groove 102 is further deepened on the first main surface of the glass base material 10, and the resist layer is not provided in the second main surface of the glass base material 10. A portion of 14 is etched to form a second region trench 104. Further, when the chemical polishing treatment is continued, as shown in FIG. 3(C), the first division groove 102 and the second division 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 holder 16 is taken out from the chemical polishing bath.

Next, the glass base material 10 is horizontally placed on the glass holder 18 in a state where the first main surface is placed upward. On the glass base material 10, other glass support members 18 (not shown) are placed as needed. Next, the glass support member 18 supporting the glass base material 10 is immersed in the chemical polishing bath. When the glass base material 10 is immersed in the chemical polishing bath, as shown in FIG. 5(A), the first zone ditch 102 and the second zone ditch 104 are further deepened, and soon the first zone ditch 102 and the second zone ditch 104 are penetrated. . Due to the first zone ditch 102 and the first The two-zone groove 104 is penetrated, and the glass base material 10 is cut, and a plurality of glass substrates 100 as shown in FIGS. 4(B) and 5(B) are obtained.

When the chemically strengthened glass having a CT value of more than about 20 is usually cut by etching, the glass substrate 100 is broken while the partition groove is penetrated. However, as described in the present embodiment, first, the single-side polishing is performed to prevent the glass substrate 100 from being broken while passing through the division groove.

Although the details of the mechanism for preventing cracking of the glass substrate 100 while the division trench penetrates are not clear, the mechanism is presumed to be as follows as a result of many experiments. That is, when the first main surface and the second main surface of the glass base material 10 are simultaneously etched, the division groove is penetrated on the center line 110 shown in FIG. 5(B), and the ridge line 112 is located on the center line 110. Here, in the chemically strengthened glass, a compressive stress layer is formed on the surface, and on the other hand, a tensile stress layer is formed on the back surface, and the tensile stress is considered to be the strongest on the center line 110. When the division groove penetrates at the portion where the tensile stress becomes the strongest, the change in the internal stress occurring at the same time as the penetration is large, and the glass substrate is predicted to be broken.

Therefore, in the embodiment of the present invention, since the ridge line 112 of the glass substrate is generated at a position where the center line 110 is shifted by the predetermined offset amount 114 when the tensile stress becomes the strongest, the single-side polishing process is employed. It has been experimentally found that the above-described offset amount 114 must be set large in principle as the CT value becomes higher. The reason for this is that the offset 114 is increased and the distance from the center line is increased, and the tensile stress inside the glass base material 10 is further lowered. On the other hand, if the offset 114 is increased above the required level, there will be strength. Alternatively, the design may be reduced. Therefore, the offset amount 114 is preferably set to be as small as possible within a range in which the glass substrate 100 can be prevented from being broken.

For example, the thickness of the glass base material 10 is about 0.5 mm to 1.2 mm, and if the CT value is about 30, the offset amount 114 is set to 50 μm to 100 μm to prevent the glass substrate 100 from being broken. For example, since the offset amount 114 is set to 50 μm, the one-sided chemical polishing treatment is performed at an etching rate of about 2 to 3 μm/min for about 20 minutes, and then the etching rate is performed at an etching rate of about 4 to 6 μm/min. The chemical polishing treatment can be carried out until the division groove is penetrated. In the present 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, but the polishing rate is appropriately increased or decreased as needed.

Next, the end surface treatment applied to the end faces of the respective glass substrates 100 will be described with reference to FIGS. 6(A) to 6(B). As shown in FIG. 6(A), the end surface of the glass substrate 100 is formed in a pointed shape at the position of the ridge line 112 at the time when the division groove is penetrated. Therefore, it is preferable to perform end surface treatment so that the end surface of the glass substrate 100 has an arc shape in cross section after the plurality of glass substrates 100 are formed through the division grooves.

When the glass substrate 100 is subjected to the end surface treatment, the glass substrate 100 is immersed in the chemical polishing bath for about 1 hour to 10 hours in a state where the glass holder 18 supports the upper and lower surfaces of the plurality of glass substrates 100. At this time, it is preferable to form the side to be etched more (in the present embodiment, the second main surface side). The reason is that the upper surface is less likely to retain sludge or the like, and the fresher chemical polishing liquid is easily circulated, so that the polishing rate is higher than the lower side. The tendency is. As shown in FIG. 6(A), the amount of polishing on the second main surface side is larger than that on the first main surface side, and the balance between the first main surface side and the second main surface side is obtained. In the present embodiment, the end surface treatment is performed by forming the side to be etched more, and the balance between the first main surface side and the second main surface side is obtained. However, the method of the end surface treatment is not limited thereto. For example, even if the difference in the circulation speed of the etching liquid is set differently or more, or the viscosity of the etching liquid is set to be different from the above, the same effect can be obtained.

The glass substrate 100 whose end surface treatment has been completed is immersed in an alkaline stripping liquid such as a mixture containing caustic or TMAH (tetramethylammonium hydroxide) and DMI (1,3-dimethyl-2-imidazolidinone). The peeling groove, as shown in Fig. 6(C), the resist 14 is peeled off. By the above treatment, a plurality of glass substrates can be stably and efficiently obtained from the chemically strengthened glass base material. In the present embodiment, an example in which the end surface treatment is performed before the resist layer 14 is peeled off will be described. However, it is not always necessary to perform the end surface treatment. Even if the ridge line 112 formed on the end surface of the glass substrate 100 is deviated from the center in the thickness direction, it is practically not problematic, and the glass substrate 100 can be used without performing end surface treatment.

In the above embodiment, an example in which the double-sided chemical polishing treatment is performed after the one-side chemical polishing treatment is performed first, but the single-sided chemical polishing treatment may be performed after the double-sided chemical polishing treatment is performed first. The same effect, so the order of processing can be changed as needed.

Next, the change of the single-side polishing process will be described using FIG. 7(A) and FIG. 7(B). In the above embodiment, the chemical resistance is performed for a predetermined period of time in a state in which the acid-resistant film 12 is adhered to the second main surface of the glass base material 10. Grinding treatment, thereby preventing the division groove from penetrating through the center in the thickness direction. The method for preventing the division groove from penetrating the center in the thickness direction can be achieved by a method other than the above-described adhesion of the acid-resistant film 12.

7(A) and 7(B), the glass base material 10 is conveyed by the conveyance roller 36, and the upper side rinse nozzle 34 and the lower side rinse nozzle 32 which are disposed on the upper and lower sides of the conveyance roller 36 are provided. A one-piece chemical polishing apparatus 30 that performs chemical polishing treatment. In the polishing apparatus 30, as shown in Fig. 7(A), the above-described acid-resistant film 12 can be used even if one-side chemical polishing treatment is performed for a predetermined period of time while ejecting the etching liquid from only the lower side eluting nozzle 34. It has the same effect as the single-side grinding process. At this time, after the one-side chemical polishing treatment as shown in FIG. 7(A), the double-sided chemical polishing treatment shown in FIG. 7(B) may be performed, or may be performed as shown in FIG. 7(A). After the one-side chemical polishing treatment, the immersion treatment of the above chemical polishing liquid tank is performed. Further, the glass support member 18 may be used to support the glass base material 10 while being conveyed as needed. In addition, the order of the one-side chemical polishing treatment and the double-sided chemical polishing treatment can also be changed.

In the above-described embodiment, an example in which a large-sized glass base material 10 is cut to obtain a plurality of rectangular glass substrates will be described. However, the shape of the glass substrate 100 is not limited to the rectangular shape shown in FIG. 8(A). The shape of the glass substrate can be formed into an arbitrary shape by appropriately changing the shape formed in the region of the resist layer 14 by the photolithography technique. If the glass base material is cut by chemical polishing treatment, as shown in FIG. 8(B), even if the plurality of circular arcs having a small radius of curvature have a continuous complicated shape, it is not a problem, and even if it is at the end The shape of the through hole 152 is not formed in the vicinity of the rim. problem.

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

The sensor element provided in the wafer field is generally less heat-resistant, so that it is difficult to chemically strengthen the glass in the wafer field. However, according to the embodiment of the present invention, the chemistry in which the wafer field is formed can be stably cut. Since the large-sized glass base material 10 is reinforced and the plurality of glass substrates 100 are obtained, the productivity can be remarkably improved particularly in the glass substrate on which the sensor elements for the touch panel are mounted.

The description of the above embodiments is illustrative in all aspects and should not be considered as limiting. The scope of the present invention is expressed by the scope of the claims and not the embodiments described above. In addition, the scope of the present invention is intended to embrace all modifications within the meaning and scope of the invention.

10‧‧‧Glass base metal

12‧‧‧acid resistant film

14‧‧‧Resist layer

16‧‧‧glass support

18‧‧‧glass support

30‧‧‧ grinding device

32‧‧‧Lower side shower nozzle

34‧‧‧Upper rinsing nozzle

36‧‧‧Transport roller

100‧‧‧ glass substrate

102‧‧‧Divulation in Zone 1

104‧‧‧District 2

110‧‧‧ center line

112‧‧‧ ridgeline

114‧‧‧Offset

152‧‧‧through holes

Fig. 1 is a schematic view showing a glass base material on which a method for producing a glass substrate according to an embodiment of the present invention is applied.

Fig. 2 is a view showing a state in which a glass base material is placed in a longitudinal direction on a glass holder.

Fig. 3 is a view showing a state in which a groove is formed in a glass base material by a chemical polishing treatment.

Figure 4 shows the placement of the glass base material in a horizontal position on the glass support. State diagram.

Fig. 5 is a view showing a state of a glass member in a state in which a division groove is penetrated.

Fig. 6 is a view showing a state in which a chemical polishing treatment is performed on an end surface of a glass substrate.

Fig. 7 is a view showing another embodiment of the present invention.

Fig. 8 is a view showing another example of a glass base material to which the present invention is applied.

10‧‧‧Glass base metal

14‧‧‧Resist layer

100‧‧‧ glass substrate

102‧‧‧Divulation in Zone 1

104‧‧‧District 2

110‧‧‧ center line

112‧‧‧ ridgeline

114‧‧‧Offset

Claims (2)

A method for producing a glass substrate, which is a glass base material to which a tempering treatment is applied, and a resist layer is formed on the first main surface and the second main surface so as to cross over a region to be cut, that is, a scribe line. A method for producing a glass substrate of a plurality of glass substrates by cutting and separating by a chemical polishing treatment, wherein the glass base material is characterized in that the chemical polishing treatment is performed only on the first main surface at a predetermined single-side polishing amount. a first chemical polishing step; and a second chemical polishing step of performing chemical polishing treatment on both the first main surface and the second main surface to form the first division groove formed on the first main surface and the second division step The second area groove of the main surface penetrates at a position offset from the center of the glass base material in the thickness direction by an amount corresponding to the one-side polishing amount. The method for producing a glass substrate according to claim 1, wherein the first region groove and the second region groove are inserted, and the end surface of the glass substrate is deformed into an end surface having an arc shape in a cross section. Processed end face processing steps.