Scribing method for brittle material substrates

Abstract

To provide a method for scribing a brittle material substrate capable of attaining prolonging the lifetime of a diamond scribing a brittle material substrate.SOLUTION: A method for scribing a fragile material substrate G along a scheduled scribing line L comprises: placing a sheet S containing a polymeric compound on the fragile material substrate G for 48 to 1000 hours; removing the sheet S; pressing a diamond-made point P of a scribing tool 1 onto the scheduled scribing line L; and moving the fragile material substrate G and the scribing tool 1 relatively to each other to scribe the fragile material substrate G.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a technique for a method of scribing a brittle material substrate such as a glass substrate or a silicon wafer with the point of a scribing tool using diamond. [Background technology]

[0002] Generally, scribing tools using scribing wheels or single-crystal diamonds are used to scribe glass substrates or silicon wafers. In scribing tools using single-crystal diamonds, the diamond is placed at a point that is the contact point with the substrate, and a scribe line is formed by the point by moving the scribing tool in a linear direction (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2017-65245 A Summary of the Invention [Problem to be solved by the invention]

[0004] In conventional scribing methods using scribing tools, the diamonds used in the points wear down with use, preventing them from fully demonstrating their ability to form scribe lines. Furthermore, in recent years, as mobile devices have become lighter and more foldable, cover glasses have become increasingly thin, leading to the development of high-strength diamonds that can be used to scribe ultra-thin glass sheets with thicknesses of 100 μm or less. While high-strength diamonds are capable of precise cutting, they also have the drawback of having a short lifespan.

[0005] The present invention has been made in consideration of the current problems described above, and an object of the present invention is to provide a method for scribing a brittle material substrate that can extend the life of the diamond used to scribe the brittle material substrate. [Means for solving the problem]

[0006] The problem to be solved by the present invention is as described above, and the means for solving this problem will now be described.

[0007] That is, the method for scribing a brittle material substrate according to the present invention is a method for scribing a brittle material substrate along a line to be scribed, and includes placing a sheet having a polymer compound on the brittle material substrate for a predetermined time and then removing it, pressing a point of a scribing tool made of diamond onto the line to be scribed, and moving the brittle material substrate and the scribing tool relatively to scribe the brittle material substrate. The thickness of the brittle material substrate is 300 μm or less, the sheet is a polyethylene sheet, and the polymer compound contains polyethylene glycol. It is characterized by: Thus, in the method for scribing a brittle material substrate according to the present invention, the lubricating components contained in the sheet adhere to the laminated brittle material substrate, thereby improving the lubricity between the brittle material substrate and the point of the scribing tool and reducing wear on the diamond tip used at the point. In addition, the PEG contained in the polyethylene sheet leaches out, providing lubricity to the surface of the brittle material substrate and reducing wear of the diamond tip used in the point. Furthermore, when multiple brittle material substrates are packed and stored in a flat stack, the PEG contained in the polyethylene sheet is more likely to leach out due to gravity, providing lubricity to the surface of the brittle material substrate and reducing wear of the diamond tip used in the point.

[0009] In the method for scribing a brittle material substrate according to the present invention, the sheet is preferably placed in an environment of 20° C. or higher and 70° C. or lower for 48 to 1000 hours. This structure allows the PEG contained in the polyethylene sheet to easily seep out, providing lubricity to the surface of the brittle material substrate and reducing wear on the diamond tip used as the point.

[0010] In addition, in the method for scribing a brittle material substrate according to the present invention, it is preferable that the plurality of brittle material substrates stacked on top of each other and the plurality of sheets interposed between the plurality of brittle material substrates are placed in a packaged state. By using this structure, the PEG contained in the polyethylene sheet is more likely to seep out while multiple brittle material substrates are packaged and stored, providing lubricity to the surface of the brittle material substrates and reducing wear on the diamond tip used as the point. [Effects of the Invention]

[0012] The present invention has the following effects. That is, according to the method for scribing a brittle material substrate of the present invention, by placing a sheet containing a polymer compound on the brittle material substrate for a predetermined time and then removing it before performing the scribing step, it is possible to improve the lubricity between the brittle material substrate and the point of the scribing tool and reduce wear of the diamond tip used in the point, thereby extending the life of the diamond tip and reducing the cost of tip replacement. [Brief explanation of the drawings]

[0013] [Figure 1] 1A and 1B are a front view and a plan view, respectively, showing a scribing tool according to one embodiment of the present invention. [Figure 2] FIG. 4 is a flow diagram showing a scribing step according to one embodiment of the present invention. [Figure 3] 1 is a front cross-sectional view showing stacked brittle material substrates according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] Next, an embodiment of the present invention will be described with reference to FIG.

[0015] [Scribe tool configuration] First, the configuration of a scribing tool used in a method for scribing a brittle material substrate embodying the present invention will be described with reference to FIG. The scribing tool 1 is a device that forms a scribe line by bringing a point P into contact with a line L to be scribed on a brittle material substrate G. As shown in FIGS. 1(A) and 1(B), the scribing tool 1 comprises a tool body 2 that is movable in the scribing direction, and a base member 3 in the form of a rectangular pillar that is attached to the tool body 2.

[0016] The tool body 2 is disposed above the brittle material substrate G and is configured to be movable parallel to the surface of the brittle material substrate G. The tool body 2 is supported so as to be horizontally movable on a work table 11 on which the brittle material substrate G is placed. The horizontal movement of the tool body 2 relative to the work table 11 is controlled by a control device (not shown), and in this embodiment, the tool body 2 is configured to be horizontally movable along a scribe line L along which the brittle material substrate G is to be cut. The brittle material substrate G is a plate-like member that is prone to breaking along scratches (cracks), and is made of, for example, a glass substrate. Examples of glass substrates that can be used include alkali-free glass, silicate glass, silica glass, and borosilicate glass. When the brittle material substrate G is a glass substrate, its thickness is preferably 300 μm or less.

[0017] The base member 3 is made of single crystal diamond. The material of the base member 3 is not limited to that of this embodiment, and may be, for example, polycrystalline diamond synthesized by a CVD (Chemical Vapor Deposition) method, polycrystalline diamond sintered from fine graphite or non-graphitic carbon without containing binders such as iron group elements, or sintered diamond in which diamond particles are bonded with a binder such as an iron group element.

[0018] At least the portion of the base member 3 where the scribe line, including the point P, will be formed must be made of single crystal diamond; the other portions may be made of metal or ceramic. The base member 3 is fixed to the side of the tool body 2 with fixing members such as screws. The base member 3 is formed as a polygonal prism with one or more vertices. The point P is formed at one or more vertices of the polygonal prism of the base member 3, at a location on the ridge that comes into contact with the brittle material substrate G. The point P is formed by an angular portion of the single crystal diamond, and is configured so that a scribe line can be formed on the surface of the brittle material substrate G.

[0019] [Scribing method using a scribing tool] Next, a scribing method using the scribing tool 1 will be described with reference to FIG. First, the brittle material substrates G are packed and stored in a stacked state (Step S05). Next, in order to scribe the brittle material substrates G, they are removed from their packed and stored state and placed one by one on the work table 11 (Step S10). Next, point P of the base member 3 is brought into contact with the starting point on the line to be scribed L (Step S30). Then, the tool body 2 is moved parallel to the line to be scribed L (Step S40). By moving the tool body 2 parallel to the line to be scribed L, scribing is performed at point P.

[0020] [Laminated brittle material substrate] Next, the packaging form for storing and transporting the brittle material substrate G in step S05 will be described. As shown in Figure 3, the brittle material substrates G are stacked flat with their wide surfaces oriented horizontally, and are stacked vertically. Between the stacked brittle material substrates G and G, sheets S are interposed to enhance cushioning and protect the surface. One sheet S is interposed between each brittle material substrate G and G. The sheet S protects both sides of the brittle material substrate G. By protecting the surface of the brittle material substrate G with the sheet S, it is possible to prevent other contaminants such as particles and fine particles generated from the substrate itself from adhering to the surface. The sheet S is made of a foamed polyethylene sheet. The sheet S has air bubbles inside the polyethylene sheet, which provides excellent shock absorption and prevents breakage due to collisions between the brittle material substrates G.

[0021] The sheet S is also placed around the outer periphery of the stacked brittle material substrates G. By protecting the peripheral surface of the brittle material substrates G, it is possible to prevent damage to the brittle material substrates G due to external forces during packaging. The peripheral surface of the brittle material substrates G may be protected by stacking the sheet S, which is slightly larger than the brittle material substrates G.

[0022] The stacked brittle material substrates G are packaged and stored while wrapped in the sheet S. The temperature of the storage location is preferably in an environment of 20°C or higher and 70°C or lower. When stored in an environment of 20°C or higher and 70°C or lower, the polyethylene glycol contained in the foamed polyethylene sheet seeps out. This causes the polyethylene glycol to adhere to the entire stacked surface of the brittle material substrates G. Because multiple brittle material substrates G are stacked flat, pressure due to their own weight is applied evenly across a wide surface. This causes the polyethylene glycol to adhere to the entire stacked surface of the brittle material substrates G.

[0023] Furthermore, it is preferable that the thickness of the packed brittle material substrate G be 300 μm or less. As the thickness of the brittle material substrate G becomes thinner, the diamond tip that is the material of the base member 3 used in the scribing process must be stronger. High-strength diamonds are capable of precise cutting, but they also have the disadvantage of having a short lifespan. Therefore, by exuding sufficient polyethylene glycol from the sheet S, it is possible to prevent wear of the diamond and extend the lifespan of the base member 3.

[0024] The laminated brittle material substrate G is left in a packaged state for 48 to 1000 hours in an environment of 20° C. or higher and 70° C. or lower. By leaving the laminated brittle material substrate G for 48 to 1000 hours, polyethylene glycol sufficient to acquire lubricity can be exuded.

[0025] By exuding sufficient polyethylene glycol onto the surface of the brittle material substrate G in advance in this way to achieve lubricity, the lubrication between the brittle material substrate G and point P of the scribing tool 1 can be improved in the scribing process from step S10 onwards, thereby reducing wear on the diamond tip used at point P.

[0026] [Example] Next, a verification experiment for determining the effectiveness of the method for scribing a brittle material substrate G embodying the present invention will be described.

[0027] In the verification experiment, a glass substrate is used as the brittle material substrate G. The brittle material substrate G is stacked and packaged in a sheet S made of a foamed polyethylene sheet. The packaged brittle material substrate G is heated in an oven. This causes polyethylene glycol to seep out of the sheet S and adhere to the surface of the brittle material substrate G. In step S10, the heated brittle material substrate G is placed on the work table 11 with the sheet S removed. Next, in step S30, point P of the base member 3 is brought into contact with a point on the line L to be scribed on the brittle material substrate G to which the polyethylene glycol has adhered. Next, in step S40, the tool body 2 is moved parallel to the line L to be scribed, thereby performing scribing at point P.

[0028] Table 1 shows the measurement results of the life of the base member 3 used in this scribing method.

[0029] In Example 1, the brittle material substrate G was stored for one week at a heating temperature of 40° C. in an oven for storing the brittle material substrate G. In Example 2, the brittle material substrate G was stored for one week at a heating temperature of 60° C. in an oven for storing the brittle material substrate G. In Example 3, the brittle material substrate G was stored for two months at room temperature.

[0030] [Table 1]

[0031] When a brittle material substrate G stored at room temperature for two weeks without being packaged in a sheet S was scribed, the life of the base member 3 was very short at 350 m or less. However, when a brittle material substrate G stored for one week at a heating temperature of 40°C in an oven was scribed as in Example 1, the life of the base member 3 was extended to 700 m. Furthermore, when a brittle material substrate G stored for one week at a heating temperature of 60°C in an oven was scribed as in Example 2, the life of the base member 3 was extended to 4,400 m. Furthermore, when a brittle material substrate G stored for two months at room temperature was scribed as in Example 3, the life of the base member 3 was extended to 700 m.

[0032] From the above results, it can be seen that by exuding sufficient polyethylene glycol onto the surface of the brittle material substrate G in advance to achieve lubricity, the lubricity between the brittle material substrate G and the point P of the scribing tool 1 can be improved, thereby reducing wear on the diamond tip used at the point P.

[0033] As described above, the present invention is a method for scribing a brittle material substrate G along a line L to be scribed, in which a sheet S having a polymer compound is placed on the brittle material substrate G for a predetermined period of time and then removed, and point P of a scribing tool 1 made of diamond is pressed onto the line L to be scribed, and scribing is performed by moving the brittle material substrate G and the scribing tool 1 relative to each other. By configuring it in this manner, the polyethylene glycol contained in the foamed polyethylene sheet seeps out, improving the lubrication between the brittle material substrate G and the point P of the scribing tool 1, thereby reducing wear on the diamond tip used at the point P. [Explanation of symbols]

[0034] 1 scribing tool 2 Tool body 3 Base material 11 Work Table G Brittle material substrate L Scribe line P Points S seat

Claims

1. A method for scribing a brittle material substrate along a line to be scribed, the method comprising: a sheet having a polymer compound is placed on the brittle material substrate for a predetermined time and then removed; Pressing a point of a scribing tool made of diamond onto the line to be scribed; Scribing by moving the brittle material substrate and the scribing tool relative to each other; The thickness of the brittle material substrate is 300 μm or less, the sheet is a polyethylene sheet, The method for scribing a brittle material substrate, wherein the polymer compound contains polyethylene glycol.

2. The sheet is placed in an environment of 20°C or higher and 70°C or lower for 48 to 1000 hours.

2. The scribing method according to claim 1.

3. a plurality of the brittle material substrates stacked on top of each other; and a plurality of sheets interposed between the plurality of brittle material substrates, and the brittle material substrates are placed in a packaged state.

3. The scribing method according to claim 1 or 2.

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