JP6572660B2 - Scribing wheel - Google Patents

Description

  The present invention relates to a scribing wheel suitable for scribing a brittle material substrate having high hardness.

  Conventionally, in a manufacturing process of a liquid crystal display panel, a solar cell, or the like, a brittle material substrate dividing process is provided. In the cutting process, the scribing wheel is applied to the surface of the brittle material substrate while applying a load corresponding to various conditions such as the material and thickness of the brittle material substrate to the scribing wheel made of cemented carbide or polycrystalline sintered diamond (PCD). A scribe line is formed by rolling up, and a vertical crack extending from the scribe line in the thickness direction of the brittle material substrate is formed. Then, by applying a predetermined force along the scribe line of the brittle material substrate, the brittle material substrate is divided to manufacture respective panels and glass plates.

  As a result of various improvements in substrate materials and heat treatment processing at glass material manufacturers, when scribing using a scribing wheel (hereinafter also referred to as a normal wheel) equipped with a conventional cutting edge (normal cutting edge) The phenomenon that the cutting edge slips on the substrate surface immediately after the scribing wheel rolls and a scribe line is not formed has been observed.

  Patent Document 1 discloses a scribing wheel having a high penetration effect. This scribing wheel has a large number of notches and protrusions alternately formed in the circumferential direction along a circumferential ridge line having a V-shaped cross section. When this scribing wheel is used, it is possible to form a vertical crack that is relatively deep with respect to the thickness of the glass substrate in the vertical direction from the surface of the glass substrate.

  Such highly penetrating cutting edge scribing wheels are known as “faster” cutting edges than normal cutting edge scribing wheels.

Japanese Patent No. 3074143

  However, when scribing a high-hardness brittle material substrate such as a ceramic harder than a glass substrate, the scribing wheel made of cemented carbide or PCD is composed of a binder such as tungsten carbide or diamond particles and cobalt, so the cutting edge May not be able to form long distance cracks due to chipping or wear. Therefore, when scribing a hard brittle material substrate, a diamond scribing wheel made of a single crystal of a hard material that is harder and more homogeneous than cemented carbide or sintered diamond is preferable. In a diamond material scribing wheel, the cutting edge is mirror-like and the surface roughness of the inclined surface is reduced. For this reason, it is considered that it is more slippery on the substrate, the “hanging” becomes worse, and it becomes difficult to generate a vertical crack immediately after the start of scribing.

  The present invention has been made in view of the problems of such a diamond material scribing wheel, and even when scribing a brittle material substrate using a diamond material scribing wheel, "hanging" is good, An object of the present invention is to provide a scribing wheel that easily generates vertical cracks.

In order to solve this problem, the scribing wheel of the present invention has a cutting edge having a V-shaped cross section composed of a ridge line made of diamond and a pair of inclined surfaces around a disk, and an arithmetic average of the pair of inclined surfaces. roughness and 0.01μm or less, more 0.5μm at a position spaced a predetermined distance from the ridge line of the inclined surface of the cutting edge, the recess of the pitch of less than 12μm is provided on the entire circumference, the depth of the recess, 0.05 .mu.m This is less than 0.7 μm .

Here, the scribing wheel may be configured such that a distance L between the end on the ridge line side of the dent along the inclined surface and the ridge line is 1 μm or more and 5 μm or less.

  Here, the scribing wheel may be made of single crystal diamond.

  Here, the depth of the dent of the scribing wheel may be 0.3 μm or less.

  According to the present invention having such a feature, depressions are formed on the inclined surface of the scribing wheel at a small pitch of less than 12 μm on the entire circumference of the inclined surfaces on both sides spaced a predetermined distance from the ridge line of the cutting edge. For this reason, it is possible to obtain good effects when scribing, and it is possible to scribe a substrate having high hardness with a deep crack immediately after the start of scribing.

FIG. 1 is a side view and a front view of a scribing wheel according to an embodiment of the present invention. FIG. 2 is an enlarged side view and front view of the cutting edge portion of the diamond wheel of the present embodiment. FIG. 3 is a cross-sectional view of the ridge line portion of the cutting edge of the scribing wheel of the present embodiment. FIG. 4 is an enlarged cross-sectional view illustrating a scribing state using the scribing wheel of the present embodiment. FIG. 5 is an enlarged side view and front view of a cutting edge portion of a scribing wheel according to a second embodiment of the present invention. FIG. 6 is an enlarged side view and front view of a cutting edge portion of a scribing wheel according to a third embodiment of the present invention.

  Hereinafter, scribing wheels according to embodiments of the present invention will be described in detail with reference to the drawings. The brittle material substrate to be processed in the present embodiment is a SiC substrate having high hardness, but is not limited to this, a glass substrate such as a liquid crystal display panel or a plasma display panel, a single crystal silicon substrate, A brittle material substrate such as a ceramic substrate or a sapphire substrate may be used. Further, “arithmetic average roughness Ra” used in the present specification is one of the parameters representing the surface roughness of industrial products defined in JIS B0601.

  The shape of the scribing wheel according to the embodiment of the present invention will be described. FIG. 1A is a front view of the scribing wheel according to the present embodiment as viewed from the central axis direction, and FIG. 1B is a side view of the scribing wheel. 2A is an enlarged side view showing the ridge line portion, and FIG. 2B is a front view thereof.

  The scribing wheel 10 of the present embodiment is a disc-shaped wheel formed of single crystal diamond, and a pin (not shown) for pivotally supporting the scribing wheel 10 at the center of the central shaft 11 as shown in FIG. Has a through-hole 12 through which is penetrated. The outer peripheral surface of the scribing wheel 10 is cut out so as to have a V-shaped cross section, a ridge line 13 is formed at the center thereof, and inclined surfaces 14a and 14b are provided on the left and right as illustrated. The inclined surfaces 14a and 14b are formed to have a convergence angle (α). The inclined surfaces 14a and 14b are processed so that the arithmetic average roughness Ra of the inclined surfaces is 0.01 μm or less.

  As shown in FIG. 2, the scribing wheel of this embodiment has depressions 15 with a constant pitch P at equal intervals at a position slightly separated from the ridge line 13 on inclined surfaces 14a and 14b including the ridge line 13 of the cutting edge. Is given all around. Here, it is preferable that the dent processing is formed at least in a portion that contacts the substrate during scribing. FIG. 3 is an enlarged cross-sectional view showing a cross-section of the blade edge portion. As shown in this figure, the distance L between the ridge line 13 along the inclined surface and the end of the dent 15 on the ridge line side is, for example, 1 μm or more and 5 μm or less. To do. The recess 15 has a substantially circular recess shape, and is formed on both sides of the ridge line 13 at a predetermined interval. The pitch P of the recesses 15 is 0.5 μm or more and less than 12 μm, preferably less than 8 μm, and more preferably 1 μm or less. The depth d of the recess 15 is 0.05 μm or more and less than 0.7 μm, preferably 0.3 μm or less.

  FIG. 4 is an enlarged cross-sectional view showing a cross-section of the blade edge portion when the glass substrate is scribed using the scribing wheel according to the present embodiment. As shown in this figure, when scribing, the tip of the blade edge bites into the glass substrate 20, and scribing is performed so that the surface of the glass 20 enters the recess 15. By forming minute recesses on both sides of the ridge line 13 in this way, a constant coefficient of friction can be secured even for a substrate such as a SiC substrate having a high hardness, and the workability can be improved. . Moreover, since the dent 15 is not hung on the ridge line 13, it is possible to improve the end face strength of the substrate when the scribing wheel 10 is used for scribing and dividing.

  The recess processing on the inclined surface of the scribing wheel formed of diamond of the present embodiment can be performed using a surface processing apparatus using a femtosecond laser. A femtosecond laser is a light source whose power is compressed in an extremely short time in units of femtoseconds, and grooves and patterns having a periodic structure can be formed in various materials. Here, as shown in FIGS. 2 and 3, the recesses are formed on the inclined surfaces 14 a and 14 b near the ridge line 13 at a constant pitch P. Then, by appropriately selecting the light source and the pulse width of the femtosecond laser, it is possible to perform the recess processing with a desired size, pitch P, and depth d.

  In this embodiment, the recess processing is circular in FIGS. 2 and 3, but may be an oval recess 16 as shown in FIG. 5 in the scribing wheel of the second embodiment. It may be a hollow in shape. In this case, since the depth of biting into the substrate can be changed when scribing, the width of the scribing load can be increased.

  Further, in the first embodiment of the present invention, as shown in FIG. 3, the depressions 15 are arranged symmetrically on the inclined surfaces 14a and 14b with respect to the ridge line 13, but FIG. 6 shows the third embodiment. As described above, the recesses 15 may be alternately formed in the inclined surfaces 14a and 14b. Moreover, the hollow 15 may be formed only in any one of the inclined surfaces 14 and 14b.

  The scribing wheel according to the embodiment of the present invention has good workability and can generate a vertical crack immediately after the start of scribing without slipping even on a substrate having high hardness. Therefore, it is possible to obtain an excellent effect that internal scribing can be performed even on a substrate having a high hardness. Further, since no slip occurs, the scribe line of the scribing wheel is uniformly worn, and the life of the scribing wheel can be further extended.

  In this embodiment, the material for the scribing wheel is single crystal diamond, but polycrystalline diamond may be used as the material. In this case as well, a scribing wheel having the same effect can be configured by applying the same recess processing to the ridge line portion of the scribing wheel.

  Further, in the present embodiment, the entire scribing wheel is made of single crystal diamond. For example, the wheel body portion made of cemented carbide or the like has a cutting edge portion made of single crystal or polycrystalline diamond. The present invention is also applicable to a scribing wheel in which is fixed by adhesion or film formation. With such a scribing wheel, it is possible to reduce the use of expensive single crystal diamond and provide an inexpensive scribing wheel.

  The present invention can be applied to a scribing apparatus for scribing a brittle material substrate having high hardness.

DESCRIPTION OF SYMBOLS 10 Scribing wheel 11 Center axis 12 Through-hole 13 Ridge line 14a, 14b Inclined surface 15, 16 Indentation

Claims (4)

There is a cutting edge having a V-shaped cross section composed of a ridge line made of diamond and a pair of inclined surfaces around the disk, and the arithmetic average roughness of the pair of inclined surfaces is 0.01 μm or less, Indentations with a pitch of 0.5 μm or more and less than 12 μm are provided on the entire circumference at positions spaced apart from the ridgeline by a predetermined distance ,
A scribing wheel having a depth of the recess of 0.05 μm or more and less than 0.7 μm . 2. The scribing wheel according to claim 1 , wherein a distance L between the end on the ridge line side of the dent along the inclined surface and the ridge line is 1 μm or more and 5 μm or less.   The scribing wheel according to claim 1 or 2, wherein the scribing wheel is made of single crystal diamond.   The scribing wheel according to any one of claims 1 to 3, wherein a depth of the recess of the scribing wheel is 0.3 m or less.

Images