HK1117818B - Method for cutting glass laminate - Google Patents

Description

Method for cutting and separating bonded glass plate

Technical Field

The present invention relates to a method for cutting and separating a glass plate, and more particularly to a method for cutting and separating a bonded glass plate in which a pair of glass plates are bonded to each other.

Background

After a scribe line is formed on the surface of the glass plate, the glass plate is cut and separated by applying stress to the scribe line. The applicant disclosed an example of a method for cutting and separating a glass plate in patent document 1.

[ patent document 1] Japanese patent application laid-open No. 2004-307318

The dicing and separating method disclosed in patent document 1 is a method capable of dicing and separating a bonded glass plate for a liquid crystal display having a plurality of liquid crystal cells. Fig. 5 is a bonded glass plate having a plurality of liquid crystal cell regions, fig. 5(a) is a plan view, and fig. 5(b) is a schematic cross-sectional view a-a of fig. 5 (a). The illustrated bonded glass plate 1 has a plurality of liquid crystal cell regions 2 between glass plates G1 and G2, and each liquid crystal cell region 2 is partitioned by a partition resin 3. In this way, all the liquid crystal cell regions 2 are entirely surrounded by the outer peripheral resin 7 in order to prevent liquid from entering the opposing gap between the glass plates G1 and G2. In addition, in the liquid crystal cell region 2, there are a case where the liquid crystal is injected at this stage and a case where the liquid crystal is injected thereafter.

Fig. 6 is a diagram for explaining the cutting and separation of the bonded glass plate disclosed in patent document 1. Fig. 6(a) is a view showing a step of forming a scribe line on the surface of the glass plate, fig. 6(b) is a view showing a step of etching the surface of the glass plate, and fig. 6(c) is a view showing a step of cutting and separating the bonded glass plate.

The bonded glass plate 8 is cut and separated in the process sequence shown in fig. 6. First, as shown in fig. 6(a), scribe lines 12a and 12b are formed on the surfaces of glass plates G1 and G2 by a diamond or cemented carbide hole cutter 11. Next, as shown in fig. 6(b), the surface of the glass plates G1 and G2 including the scribe lines 12a and 12b is etched by immersing the bonded glass plate in an etching solution. Then, mechanical stress due to load and traction is applied to the scribe lines 12a and 12b, and the bonded glass plate is cut and separated along the scribe lines 12a and 12 b.

According to the invention described in patent document 1, since the etching liquid is brought into contact with the bonded glass plate to remove cracks of the glass generated when the scribe lines are formed, an effect is obtained that the bonded glass plate can be smoothly cut and separated thereafter.

However, in recent years, thinning of a liquid crystal display has been advanced due to thinning of a glass plate. However, in the cutting and separating method disclosed in patent document 1, there is a possibility that breakage occurs in the bonded glass plate at the time of the cutting and separating step shown in fig. 6 (c). In particular, when the bonded glass plate is pushed by a liquid flow and deflected while being immersed in the etching solution, the glass plates G1 and G2 may be broken from the scribe lines 12a and 12 b. When the bonded glass plate is taken out from the etching solution, breakage may occur from the scribe lines 12a and 12 b.

Such a problem of breakage makes the bonded glass plate manufactured through various processes useless. As described above, in the present day when the size of the bonded glass plate is increased for the purpose of increasing the efficiency of the manufacturing process and increasing the screen size of the display screen, the problem is further exacerbated.

Further, if the etching amount is increased in order to make the bonded glass plate as thin as possible, there is a problem that the cut line (scribe line) which has been formed sharply is completely smoothed in the process of chemical polishing itself deeply by etching, and it is difficult to perform the subsequent cutting and separation.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a cutting and separating method which does not cause breakage during the process of thinning a glass plate even when the glass plate is further thinned, and which can smoothly cut and separate the glass plate after thinning.

Disclosure of Invention

In order to achieve the above object, the present invention is a method for cutting and separating a bonded glass plate including a first glass plate and a second glass plate, including a first step of forming a first scribe line on a surface of the first glass plate, a second step of bringing an etching solution into contact with the first scribe line, a third step of forming a second scribe line corresponding to the first scribe line on a surface of the second glass plate of the bonded glass plate having undergone the second step, and a fourth step of applying a stress to the bonded glass plate to cut and separate the bonded glass plate along the two scribe lines, in this order.

The cutting and separating method can be inserted into the manufacturing process of the flat display panel and the manufacturing process of the flat display. In addition, in the fourth step, the glass is preferably cut and separated by mechanical stress or thermal stress.

In the present invention, it is preferable that a pre-step of bringing an etching solution into contact with the adhesive glass plate to thin the entire plate is provided before the first step. By providing such a pre-step, the etching amount in the second step can be limited to about 10 to 60 μm for both the first glass plate and the second glass plate, and the notch groove formed by the scribe line in the second step is not more than necessary smoothly. In any case, the polishing amount in the second step is less than 100. mu.m, preferably 10 to 60 μm, more preferably 10 to 40 μm, for each glass plate.

In addition, the present invention is a flat panel display comprising a second glass plate exposed to a user and a first glass plate not exposed to the user, wherein the entire side surface of the peripheral edge of the second glass plate is physically cut and separated, and at least a part of the outer surface side of the peripheral edge of the first glass plate is smoothed by further etching a physically formed cut line.

In the present invention, at least the peripheral edge line on the outer surface side of the first glass plate, which is not exposed to the user, is smooth, and cracks of the glass, which are generated when the scribe lines are formed, can be completely removed. Therefore, when the completed flat panel display is used, the flat panel display is less likely to break even if pressure is applied to the first glass plate G1 from the second glass plate G2 exposed to the user (see fig. 1 (b)). That is, since the peripheral edge line L1 on the outer surface side of the first glass sheet G1 which is most easily extended by pressure is smooth, there is no starting point at the time of glass breakage, and excellent breakage resistance is exhibited.

In addition, in order to improve the breaking strength as much as possible, the flat panel display may be subjected to the post-process defined in the fourth aspect. In this case, the peripheral edges of the first glass sheet G1 and the second glass sheet G2 may be made smooth over their entire sides. However, in a normal use state, the flat panel display having the structure of the eighth invention exhibits sufficient breakdown strength.

In addition, it is also good to adopt the structure described in the fifth invention in order to improve the fracture resistance. The fifth invention is a method for cutting and separating a bonded glass plate composed of a first glass plate and a second glass plate, comprising a first etching step, a dicing step, a second etching step, and a separating step, the first etching step is to bring the etching solution into contact with the entire bonded glass plate and to reduce the thickness of the bonded glass plate to a thickness closest to a target plate thickness, the scribing step forms a pair of scribing lines corresponding to each other on the surfaces of the first glass plate and the second glass plate which have undergone the first etching step, the second etching step is followed by bringing an etching solution into contact with the entire bonded glass plate to reduce the thickness of the bonded glass plate to a target thickness, a separation step of applying a stress to the bonded glass plate subjected to the second etching step to cut and separate the bonded glass plate along the pair of scribe lines, the etching amount in the second etching step is limited to less than 100 μm for each glass plate. The amount of etching to be limited is more preferably 10 to 60 μm, most preferably 10 to 40 μm.

According to the present invention, even when the glass plate is further thinned, the glass plate is not broken in the process of thinning. In addition, the bonded glass plate can be cut and separated smoothly even after the thinning.

Drawings

Fig. 1 is a process flow chart of a method for cutting and separating a bonded glass plate according to a first embodiment.

Fig. 2 is a diagram for explaining the respective steps in fig. 1.

Fig. 3 is a process flow chart of a method for cutting and separating a bonded glass plate according to a second embodiment.

Fig. 4 is a diagram for explaining the respective steps in fig. 3.

Fig. 5 is a diagram showing a bonded glass plate having a plurality of display regions.

Fig. 6 is a diagram for explaining a conventional example of a method of separating and cutting a bonded glass plate.

Detailed Description

Next, a method for cutting and separating a glass plate according to the present invention will be described with reference to embodiments. Fig. 1(a) is a process flow chart of a method for cutting and separating a bonded glass plate according to a first embodiment. Here, the bonded glass plate composed of the second glass plate G2 exposed to the user and the first glass plate G1 not exposed to the user is thinned to a target plate thickness value T, and a cut groove having an appropriate depth is formed.

Specifically, the cutting and separating method is performed by sequentially performing an etching step (ST1), a first dicing step (ST2), an additional etching step (ST3), a second dicing step (ST4), and a cutting and separating step (ST5), wherein the etching step (ST1) chemically polishes the bonded glass plate until the bonded glass plate is closest to a target plate thickness value, the first dicing step (ST2) forms a first dicing line, which is a cutting-cut line, on a surface of the first glass plate G1 that is not exposed to a user, the additional etching step (ST3) brings an etching liquid into contact with the first dicing line, the second dicing step (ST4) forms a predetermined second dicing line on a surface of the second glass plate G2, and the cutting and separating step (ST5) applies stress to the dicing line formed on the surfaces of the first glass plate and the second glass plate to cut and separate the bonded glass plate.

Fig. 5 is a diagram showing the bonded glass plate 1 to be cut and separated in each embodiment, fig. 5(a) is a plan view, and fig. 5(b) is a schematic cross-sectional view a-a in fig. 5 (a). The bonded glass plate 1 shown in the drawing has a thickness of 1.4mm or less and a size of 400mmX500mm, and is used for a liquid crystal display panel. The adhesive glass plate 1 is formed by bonding a second glass plate G2 serving as an image display surface of a liquid crystal display and a first glass plate G1 serving as a rear surface of the image display surface, which are exposed to a user.

A thin film transistor and a transparent electrode are formed on a surface of the first glass plate G1 opposite to the second glass plate G2, and an alignment film (not shown) is further laminated. On the other hand, on the surface of the second glass plate G2 which is the image display surface facing the first glass plate G1, color filters divided by a black matrix are formed, and a protective layer, a transparent electrode, and an alignment film (not shown) are sequentially laminated. The glass plates G1 and G2 are bonded by interposing a spacer and partitioning resin 3 and an outer peripheral resin 7, not shown, between the two glass plates G1 and G2. After the cutting and separating step (ST5) of the present embodiment, a polarizing plate is attached to the outer surface of the adhesive glass plate 1.

The liquid crystal cell region 2 as a liquid crystal enclosing region is located between the glass plates G1, G2. The liquid crystal cell region 2 is formed by providing a partition resin 3 when bonding the glass plates G1 and G2. Further, an outer peripheral resin 7 surrounding the entire liquid crystal cell region 2 is provided, and a sealed space for preventing the etching liquid from entering is formed.

Next, the dicing and separating method according to the present embodiment will be described with reference to the drawings. Fig. 2 is a diagram for explaining the respective steps in fig. 1. Fig. 2a shows the first dicing step (ST2), fig. 2b shows the additional etching step (ST3), fig. 2 c shows the second dicing step (ST4), and fig. 2 d shows the dicing step (ST 5).

Before the first dicing step (ST2), an etching step (ST1) is provided, and the bonded glass plate 1 is etched until the thickness is closest to the target value T and becomes T + δ. Here, the under-etching value delta is less than 200 μm, preferably 20 to 120 μm, more preferably 20 to 80 μm, as the whole of the bonded glass plate 1. Therefore, when the etching shortage is converted into each of the glass plates G1 and G2, the gap between the glass plates G1 and G2 is neglected and is less than 100 μm, preferably 10 to 60 μm, more preferably 10 to 40 μm.

Then, in the first scribing step (ST2), as shown in fig. 2(a), a scribe line 5a having a depth of about 10 to 15% of the thickness of the first glass plate G1 is formed on the surface thereof. The scribe line 5a is formed by the peripheral surface of the disc-shaped hole cutter 4 made of diamond or cemented carbide and having a pointed peripheral surface. The scribe lines 5a are formed between adjacent liquid crystal cell regions 2 for dividing each liquid crystal cell region 2. The scribe line (dicing line) 5a is formed into a dicing groove by etching, and becomes a scribe line of the glass sheet G1 in the dicing step ST 5.

In the additional etching step (ST3) shown in fig. 2(b), after the etching solution is brought into contact with the outer surface of the bonded glass plate 1, water washing is performed to remove the etching solution from the surface of the bonded glass plate 1. The contact of the etching solution is performed by etching the surfaces of the glass plates G1 and G2 including the scribe line 5 a. The etching in this step is performed by immersing the bonded glass plate 1 in an etching solution. The etching solution is not particularly limited as long as it is a liquid that is soluble in glass, but in the present embodiment, an aqueous solution containing hydrogen fluoride at a concentration of 55% or less is used.

In this additional etching step, the glass plates G1 and G2 are etched so that the underetch value δ (in other words, the additional etching amount) is reduced to a thin plate. Therefore, the additional etching can reliably remove the cracks on the surface of the glass sheet G1 generated when the scribe line 5a is formed. However, since the etching amount is limited, the dicing kerf having grown from the scribe line 5a is not completely smoothed.

In the second dicing step (ST4) following the additional etching step (ST3), as shown in fig. 2(c), second dicing lines 5b, which become cutting lines of the glass sheet G2 in the cutting and separating step (ST5), are formed on the surface of the second glass sheet G2. The second scribe line 5b is formed at a position corresponding to the first scribe line 5a, and is formed between the adjacent display regions 2 through the hole cutter 4.

In this manner, in the dicing and separating method, in the second dicing step (ST4), the dicing line 5b is first formed on the second glass plate G2. That is, since the scribe line 5b serving as the starting point of the glass breakage is not formed on the second glass plate G2 at this stage, the second glass plate G2 functions as a mechanical reinforcing plate for the first glass plate G1 in the etching step (ST3) up to the second etching step (ST4) and the conveyance step of the bonded glass plate 1.

In the cutting and separating step (ST5), as shown in fig. 2(d), the bonded glass plate 1 is cut and separated with the scribe lines 5a and 5b as dicing lines. In this step, stress is applied to the scribe lines 5a and 5b by the load, and the bonded glass plate 1 is cut and separated along the scribe lines 5a and 5b by the stress. Since the scribe line 5a is grown into a cut groove from which the crack is removed by the etching process, the cut surface of the glass sheet G1 after the cutting and separation is smoother than the cut surface of the glass sheet G2.

The bonded glass plate 1 cut through the above steps is used as a display panel. In this display panel, since the cut surface of the first glass plate G1 is a smooth surface, even if a load is applied from the outside of the panel, breakage of the bonded glass plate 1 can be reliably suppressed.

Fig. 3 is a flowchart showing a dicing separation method according to a second embodiment. The cutting and separating method according to the second embodiment is performed by sequentially performing an etching step (ST10), a scribing step (ST11), an additional etching step (ST12), and a cutting and separating step (ST13), wherein the etching step (ST10) chemically polishes the bonded glass plate 1 until the thickness value is closest to the target thickness value T, the scribing step (ST11) forms scribing lines 5a and 5b as dicing lines as a whole on the respective surfaces of the first glass plate G1 and the second glass plate G2, the additional etching step (ST 4935) dips the bonded glass plate 1 in an etching solution to reduce the thickness to the target thickness T, and the cutting and separating step (ST13) applies stress to the scribing lines 5a and 5b formed on the surfaces of the first glass plate G1 and the second glass plate G2 to cut and separate the bonded glass plate.

In the etching step (ST10), the bonded glass plate is thinned to T + δ, which is slightly thicker than the target plate thickness T, as in the case of the first embodiment. Delta is less than 200. mu.m, preferably 20 to 120. mu.m, more preferably 20 to 80 μm.

The scribe line formed in the etching step (ST11) is formed to a predetermined depth of about 10 to 15% of the thickness T + δ at that time. In this case, the glass substrate can be effectively prevented from being damaged in each subsequent operation by controlling the depth from the start point to the end point of each scribe line to be uniform and controlling the depth to be uniform for each of the plurality of scribe lines.

After the dicing step, in the additional etching step (ST12), only the plate thickness δ in the above numerical range is etched, but the etching is performed in a state where the flow is completely stopped or in a state where the flow is gentle so that the bonded glass plate is not pushed by the flow.

According to the cutting and separating method of the second embodiment, the peripheral edges of the first glass plate G1 and the second glass plate G2 of each bonded glass plate after cutting and separation are made smooth by etching, in a part of the outer surface side of the side surfaces, and therefore, extremely excellent breaking resistance is exhibited against stress from the outside.

Two embodiments have been specifically described above, but the present invention is not limited to the above embodiments. For example, although the bonded glass plate for a liquid crystal display is described in fig. 1 to 5, it is not necessarily intended whether the bonded glass plate is a bonded glass plate for a liquid crystal display as long as the bonded glass plate bonds a pair of glass plates.

In order to further improve the mechanical strength of the bonded glass plate 1 after the cutting and separation, it is preferable that the side surfaces of the peripheral edges of the first glass plate G1 and the second glass plate G2 are subjected to final etching entirely or partially on each of the separated bonded glass plates.

Claims (6)

1. A method for cutting and separating a bonded glass plate for a flat panel display, which comprises a first glass plate which is not exposed to a user of the flat panel display and a second glass plate which is exposed to the user of the flat panel display,

characterized in that the first process, the second process, the third process and the fourth process are sequentially carried out,

the first step is to form a first scribe line on the surface of the first glass plate,

the second step is to immerse the bonded glass plate in an etching solution to bring the etching solution into contact with the first scribe line,

a third step of forming a second scribe line corresponding to the first scribe line on the surface of the second glass plate of the bonded glass plate having undergone the second step,

the fourth step applies stress to the bonded glass plate and cuts and separates the bonded glass plate along the two scribe lines.

2. The dicing and separating method according to claim 1, wherein a pre-step of bringing an etching solution into contact with the bonded glass plate to thin the entire surface is provided before the first step.

3. The dicing and separating method according to claim 2, wherein in the second step, the first glass plate and the second glass plate are thinned together by bringing the entire bonded glass plate into contact with an etching solution.

4. The cutting and separating method according to claim 3, wherein a post-step of bringing an etching solution into contact with the peripheral edge of each of the bonded glass plates to be cut and separated is provided after the fourth step.

5. A method of manufacturing a flat display panel, characterized in that the cutting and separating method according to any one of claims 1 to 4 is performed in a manufacturing process.

6. A method for manufacturing a flat panel display, characterized in that the cutting and separating method according to any one of claims 1 to 4 is performed in a manufacturing process.