Glass substrate manufacturing method

Abstract

To provide a glass substrate manufacturing method capable of efficiently manufacturing a glass substrate having a desired shape using a glass preform for multi-chamfering by etching.SOLUTION: A glass substrate manufacturing method according to the present invention includes at least a first laser modification step, a second laser modification step, a masking step and an etching step. The second laser modification step emits a laser beam along a first modification line 12 inside the first modification line 12, and thereby forms a second modification line 14 modified to properties to be easily etched so as to adjust an end face shape of the glass substrate. The second modification line 14 is formed in only a partial region in a thickness direction including a first main surface vicinity. An etching-resistant film 16 is formed so as to cover a first main surface.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a glass substrate manufacturing method for manufacturing a glass substrate having a desired shape, and more particularly to a glass substrate manufacturing method for obtaining a plurality of glass substrates from a glass base material for multiple glass substrates by etching. [Background technology]

[0002] As a method for efficiently manufacturing glass substrates having a desired shape, a method of efficiently obtaining multiple glass substrates by dividing (dividing) a glass base material for multiple glass substrates has been widely adopted.

[0003] However, depending on the method used to separate (single) a multi-panel glass base material, scratches may appear on the edge of the glass substrate after separation (single), which can reduce the strength of the glass substrate. This problem is particularly common when separating (single) a multi-panel glass base material using physical force.

[0004] Therefore, some prior art techniques involve chemically dividing (dividing) a multi-faceted glass base material by applying an etching-resistant mask with a desired pattern to the main surface of the multi-faceted glass base material and then performing an etching process (see, for example, Patent Document 1).

[0005] It was also said that by chemically dividing (slicing) the glass base material for multi-faceting, scratches would be less likely to occur on the edge surfaces of the glass substrate after division (slicing), thereby eliminating the problem of reduced strength of the glass substrate. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-167086 Summary of the Invention [Problem to be solved by the invention]

[0007] However, when dividing (slicing) a glass base material for multiple glass substrates by etching, the individual glass substrates tend to scatter after division (slicing), making recovery difficult.

[0008] In order to address such a problem, a countermeasure has been taken in which an etching-resistant film is attached to one main surface of the glass base material for multiple glass sheets while etching is performed.

[0009] In this case, however, the etching solution advances only from one main surface side, which can make it difficult to adjust the end faces of the glass substrate after division (single division) into a desired shape.

[0010] An object of the present invention is to provide a method for manufacturing a glass substrate, which can efficiently manufacture a glass substrate having a desired shape by etching using a glass base material for multiple glass substrates. [Means for solving the problem]

[0011] A glass substrate manufacturing method according to the present invention is for manufacturing a glass substrate having a desired shape, and includes at least a first laser modification step, a second laser modification step, a masking step, and an etching step.

[0012] In the first laser modification step, a laser is irradiated onto a glass base material for multiple glass substrates at a position corresponding to the shape of the glass substrate, thereby forming a first modification line at the position corresponding to the shape of the glass substrate, which has been modified to have properties that make it easier to etch.

[0013] In the second laser modification step, a laser is irradiated along the first modification line inside the first modification line to form a second modification line that is modified to have properties that make it easier to etch in order to adjust the edge shape of the glass substrate.

[0014] In the masking step, an etching-resistant mask is applied to one main surface of the glass base material for multiple beveling. Examples of the etching-resistant mask include, but are not limited to, an acid-resistant film or an acid-resistant resist agent having etching resistance.

[0015] In the etching step, the glass base material for forming multiple facets is brought into contact with an etching solution to perform an etching treatment.

[0016] The first reforming lines described above are formed across the entire thickness direction from the first main surface to the second main surface, while the second reforming lines are formed only in a partial thickness direction region, including the vicinity of the first main surface (here, "vicinity" is interpreted as the range from the first main surface to about one-fourth of the thickness). Here, "entire thickness direction" generally refers to the entire thickness direction region of the glass preform for multiple glass sheets before etching, but in cases where the etching process involves thinning (slimming) of the glass preform for multiple glass sheets, this is interpreted to include the entire thickness direction region of the glass preform for multiple glass sheets after thinning (slimming). In short, as long as the glass preform for multiple glass sheets can be divided using the first reforming lines, it is not necessary for the first reforming lines to be formed across the entire thickness direction region of the glass preform for multiple glass sheets before etching.

[0017] For example, in the first laser modification step, the laser focusing area is expanded to cover the entire thickness direction of the glass base material for multiple bezels (in the case of thinning the glass base material for multiple bezels, at least the entire thickness direction after thinning), while in the second laser modification step, the laser focusing area is adjusted to cover a portion of the thickness direction of the glass substrate.

[0018] The etching-resistant mask is applied so as to cover the first main surface, in order to provide the etching-resistant mask so as to be in contact with the second modification line.

[0019] In the above-described configuration, the surface (second main surface) opposite to the main surface on which the etching-resistant mask is applied comes into contact with the etching solution during the etching process. First, the first modification line is dissolved by the etching solution, and the etching solution reaches the first main surface at the position where the first modification line is formed.

[0020] Thereafter, the etching-resistant mask dissolves at the attached portions when it comes into contact with the etching solution, and the etching-resistant mask begins to peel off from the first main surface starting from these dissolved portions, creating a gap between the etching-resistant mask and the first main surface.

[0021] The etching liquid tends to rapidly penetrate into the gap between the etching-resistant mask and the first main surface, and therefore easily reaches the second modification line provided near the inside of the first modification line.

[0022] Thereafter, the etching solution reaches the second modification line, and the etching process proceeds from the first main surface side toward the second main surface side.

[0023] As a result, even though the etching is performed on one side with the first main surface covered with an etching-resistant mask, it is possible to obtain an end face shape similar to that obtained when etching is performed from both main surfaces.

[0024] Furthermore, due to the presence of the etching-resistant mask, even after the multi-faceted glass base material is divided (segmented) into glass substrates of the desired shape, the individual glass substrates do not scatter, making it possible to maintain high production efficiency.

[0025] In the above-described method for manufacturing a glass substrate, the second modification line is preferably formed only in a region near the first main surface that occupies half or less of the thickness direction.

[0026] This is because the etching solution flowing from the second main surface toward the first main surface can be prevented from unintentionally contacting the second modification line, making it easier to obtain a glass substrate with the intended edge shape. [Effects of the Invention]

[0027] According to the present invention, it is possible to efficiently manufacture glass substrates having a desired shape by etching using a glass base material for multiple glass substrates. [Brief explanation of the drawings]

[0028] [Figure 1] 1 is a diagram showing an outline of a process for a multi-faceted glass base material according to an embodiment of the present invention. [Figure 2] 1 is a diagram showing an outline of a process for a multi-faceted glass base material according to an embodiment of the present invention. [Figure 3] 1 is a diagram showing an outline of an etching apparatus applied to one embodiment of the present invention; [Figure 4] 1A and 1B are diagrams illustrating an outline of a mechanism by which a desired end face shape is obtained on a glass substrate. [Figure 5] FIG. 10 is a diagram showing another example of an etching apparatus applied to one embodiment of the present invention. [Figure 6] 10A and 10B are diagrams illustrating an example of a state in which glass substrates are recovered from a multi-faceted glass base material. DETAILED DESCRIPTION OF THE INVENTION

[0029] An example of a method for manufacturing a glass substrate 10 according to one embodiment of the present invention will be described below with reference to the drawings. Here, the glass substrate 10 is used as a cover glass for a smartphone, but the use of the glass substrate 10 is not limited to this. The glass substrate 10 can be used for any glass product that uses plate-shaped glass.

[0030] When manufacturing a glass substrate 10 having a desired shape, a glass base material 100 is used to obtain multiple glass substrates 10 in order to increase production efficiency.

[0031] 1(A) and 2(A), first, a laser is irradiated along a planned shape line corresponding to the shape of the glass substrate 10 (corresponding to a first laser modification step). As a result, the first modification line 12 (planned shape line) that defines the outline of the glass substrate 10 is modified to have a property that makes it easier to etch.

[0032] When forming the first modification line 12, as shown in FIG. 2(A), the laser device is set so that the focused area (the range of the focal line, which is the collection of focal points) extends over the entire area in the thickness direction of the glass base material 100.

[0033] 1(B) and 2(B), a laser is irradiated onto the planned positions for forming grooves for adjusting the end face of each glass substrate 10 (corresponding to a second laser modification step). As a result, the second modification lines 14 for adjusting the end face of each glass substrate are modified to have properties that make them more susceptible to etching.

[0034] When forming the second modified line 14, in this embodiment, the focused region of the laser beam is set only near the surface of the glass base material 100 in the thickness direction, as shown in FIG. 2(B).

[0035] The depth of this light-collecting region may be adjusted appropriately depending on the desired shape of the end face of the glass substrate 10, but is preferably kept to about 25% to 50% of the total thickness of the glass base material 100.

[0036] In this way, it is possible to switch between laser processing for drawing the second modification line 14 to adjust the end face shape of the glass substrate 10 and laser processing for forming the contour of the glass substrate 10 (forming the first modification line 12) by the simple task of adjusting the focal position of the laser beam.

[0037] In the above-described laser processing, the type and irradiation conditions of the laser beam are not particularly limited as long as they can modify the glass base material 100 so that it is easily etched.

[0038] In this embodiment, a laser beam emitted from a short pulse laser (for example, a picosecond laser or a femtosecond laser) is emitted from the laser head, but for example, a CO 2 laser, a nanosecond laser, or the like may also be used.

[0039] In this embodiment, the output is controlled so that the average laser energy of the laser beam is about 30 μJ to 300 μJ, but the invention is not limited to this.

[0040] 1(C) and 2(C), an etching-resistant film 16 is attached to one main surface of the glass base material 100 for multiple glass panels. The etching-resistant film 16 is applied so as to cover the main surface on which the second modification lines 14 are formed.

[0041] Here, an etching-resistant film 16 having self-adhesiveness and etching resistance is used, but instead of the etching-resistant film 16, an acid-resistant resist agent or other masking agent can also be used.

[0042] Next, the glass base material 100 whose properties have been modified so that the desired locations are easily etched is introduced into an etching device 50 as shown in FIGS. 3(A) and 3(B), and is subjected to an etching process.

[0043] 3(B), the glass base material 100 is introduced into an etching device 50 and subjected to etching using an etching solution containing, for example, hydrofluoric acid and hydrochloric acid. Typically, an etching solution containing about 1 to 10% by weight of hydrofluoric acid and 0 to 20% by weight of hydrochloric acid is used, and a surfactant or the like is used in combination as needed.

[0044] In the etching device 50, as shown in FIG. 3(B), the glass base material 100 is transported by a transport roller while an etching solution is brought into contact with the main surface of the glass base material 100 in the etching chamber 52, thereby performing an etching process on the glass base material 100.

[0045] In addition, a cleaning chamber 53 is provided downstream of the etching chamber 52 in the etching apparatus 50 to wash away the etching liquid adhering to the glass base material 100, so that the glass base material 100 is discharged from the etching apparatus 50 with the etching liquid removed.

[0046] The first modification line 12 and the second modification line 14 formed by the irradiation of the laser beam are dissolved more quickly than other portions by the etching process using the etching device 50. As a result, the outer shape of the glass substrate 10 is defined along the planned cutting line, and the desired edge shape is obtained.

[0047] Specifically, as shown in Fig. 4(A), the etching process brings the surface (second main surface) of the etching-resistant film 16 opposite to the main surface on which the mask is applied into contact with the etching solution. First, the first modified line 12 is quickly dissolved by the etching solution.

[0048] As a result, as shown in Fig. 4(B), the etching liquid eventually reaches the first main surface at the position where the first modification line is formed, that is, a groove penetrating in the thickness direction is formed.

[0049] Thereafter, the etching-resistant film 16 comes into contact with the etching solution and dissolves at the attached portion, and the etching-resistant film 16 begins to peel from the first main surface from the dissolved portion as a starting point, resulting in a gap between the etching-resistant film 16 and the first main surface, as shown in FIG.

[0050] The etching solution tends to rapidly penetrate into the gap between the etching-resistant film 16 and the first main surface, and therefore easily reaches the second modification line 14 located near the inside of the first modification line 12.

[0051] Thereafter, the etching solution reaches the second modification line 14, and the etching process proceeds from the first main surface side to the second main surface side, as shown in FIG. 4(D).

[0052] As a result, even though the etching is performed on one side with the first main surface covered with the etching-resistant film 16, it is possible to obtain an end face shape (see region 142 in the figure) similar to that obtained when etching is performed from both main surfaces, as shown in Figure 4(E).

[0053] Furthermore, since the region to be etched is modified by a technique that assists the etching process by irradiation with a laser beam (laser-assisted etching), it is possible to shorten the etching process time.

[0054] Here, the spray etching process has been described, but instead of spray etching, it is also possible to adopt a configuration in which the glass base material 100 is transported in an overflow type etching chamber 54 while coming into contact with the overflowing etching solution, as shown in Figure 5(A).

[0055] Furthermore, as shown in Figure 5(B), it is also possible to employ dip etching in which one or more glass base materials 100 contained in a carrier are immersed in an etching tank 56 containing an etching solution.

[0056] Regardless of the etching method used, the etching-resistant film 16 is attached to each glass substrate 10, so that the glass substrates 10 are less likely to scatter even after being cut (separated) into individual glass substrates 10, as shown in Fig. 6. This makes it possible to maintain high production efficiency in the manufacture of the glass substrates 10.

[0057] 6 shows an example in which the glass substrates 10 attached to the etching-resistant film 16 are sequentially collected, but the collection method is not limited to this. For example, the etching-resistant film 16 may be peeled off while the main surface opposite to the attached surface of the etching-resistant film 16 is adsorbed by an adsorption stage.

[0058] By using the manufacturing method described above, it is possible to obtain an edge shape of the glass substrate 10 that is substantially the same as if it had been subjected to double-sided etching, despite the fact that only one side has been etched.

[0059] The end face shape of the glass substrate 10 can be made closer to the desired shape by adjusting the formation position of the second modification line 14 (distance from the first modification line 12), adjusting the depth of the second modification line 14, adjusting the adhesion between the etching-resistant film 16 and the glass base material 100, etc.

[0060] The above-described embodiments should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined not by the above-described embodiments but by the claims. Furthermore, the scope of the present invention is intended to include all modifications that are equivalent to the claims and fall within the scope thereof. [Explanation of symbols]

[0061] 10-Glass substrate 12-First reforming line 14-Second reforming line 16-Etching resistant film 50-Etching equipment 100-Multiple faceted glass substrate

Claims

1. A glass substrate manufacturing method for manufacturing a glass substrate having a desired shape, comprising: A first laser modification step of irradiating a laser onto a glass base material for multiple cutting of the glass substrate at a position corresponding to the shape of the glass substrate to form a first modification line modified to have an easily etchable property at a position corresponding to the shape of the glass substrate; A second laser modification step of forming a second modification line modified to have a property that is easily etched in order to adjust the end face shape of the glass substrate by irradiating a laser along the first modification line inside the first modification line; a masking step of applying an etching-resistant mask to one main surface of the glass base material for multiple faceting; an etching step in which the glass base material for multiple faceting is subjected to an etching treatment by contacting it with an etching solution; At least The first reforming line is formed over the entire thickness direction from the first main surface to the second main surface, while the second reforming line is formed only in a partial region in the thickness direction including the vicinity of the first main surface, and The method for manufacturing a glass substrate, wherein the etching-resistant mask is applied so as to cover the first main surface.

2. 2. The glass substrate manufacturing method according to claim 1, wherein the second modification line is formed only in a region that is equal to or smaller than half of the thickness direction and includes a region near the first main surface.

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