HK1155714A - Cutter wheel - Google Patents

Abstract

A cutter wheel capable of forming a highly penetrable scribe line is provided. Two segments of cutting surfaces are provided along a periphery of the cutter wheel. The cutting surface includes a first cutting surface having a v-shaped cross-section and forming an edge line with a first edge angle φ1 and a second cutting surface connected to a root side of the first cutting surface. The second cutting surface is formed so that a virtual second edge angle φ2 formed by extending the second cutting surface to a side of the first cutting surface is smaller than the first edge angle φ1. A groove with a depth reaching the second cutting surface is periodically formed along the edge line of the first cutting surface, so that the second cutting surface and the first cutting surface are cut into a processed substrate together to form a scribe line.

Description

Cutter wheel

Technical Field

The present invention relates to a cutter wheel for forming a scribe line on a substrate made of a brittle material such as glass by rotating the cutter wheel on the substrate, and more particularly, to a grooved cutter wheel capable of forming a scribe line (high-permeability scribe line) in which a crack (vertical crack) formed in a vertical direction (a direction perpendicular to a substrate plane) along the scribe line deeply penetrates.

Background

Generally, a cutter wheel for forming a scribe line on a glass substrate is configured such that a disk made of cemented carbide or sintered diamond is polished from both sides along an outer peripheral surface to form a blade surface having a V-shaped cross section on the outer peripheral edge and a ridge line as a blade edge.

In such a cutter wheel, if the edge line angle (also referred to as a sharp edge angle) formed by the edge surfaces on both sides of the edge point is too small, a scribe line cannot be formed by a normal pressure contact load, and if the pressure contact load is too large, the cutter wheel is immediately broken in an irregular direction. On the other hand, if the ridge angle is too large, the pressure-bonding load is dispersed in the horizontal direction, and therefore, the pressure-bonding load must be increased to form a scribe line, and further, since the load dispersed in the horizontal direction is also increased, a horizontal crack (a crack in a direction deviating from the vertical direction (a direction perpendicular to the substrate plane) and a chip (a notch) is easily formed) which causes a reduction in the quality of the cross section. Therefore, in a general cutter wheel, a scribe line can be reliably formed on a substrate by setting the edge angle to an appropriate angle, specifically, 100 ° to 160 °, and usually, about 110 ° to 150 °.

On the other hand, a grooved cutter wheel in which grooves are periodically formed along a ridge line as a cutting edge is used (see patent document 1). The grooved cutter wheel has the following features.

First, the edge portions (projections) and the groove portions are alternately rotated on the substrate, and therefore the projections are easily cut into the substrate, but the groove portions sequentially positioned on the substrate function as resistance to limit the cutting of the edge, and "cut suppression" is performed so as not to cut the edge too deeply into the substrate. Thus, even when a load is large, it is possible to prevent the occurrence of a fracture or a horizontal crack in an irregular direction due to excessive cutting of the blade edge having a large ridge angle, and to form a scribe line whose direction is controlled. Further, the blade tip intermittently contacts the substrate by the blade tip portion and the groove portion alternately approaching the substrate. As a result, since the scribe line is formed while the substrate is subjected to the dotting impact, the depth of the vertical crack extending along the scribe line is far deeper than the depth of the crack formed along the scribe line formed by the (non-grooved) ordinary cutter wheel. Further, the pressing load is intensively applied to the blade tip portion, and the depth of the crack also becomes deep.

Thus, by using the grooved cutter wheel, a scribe line having a high permeability can be formed linearly as compared with a (non-grooved) ordinary cutter wheel, and the occurrence of a crack in an irregular direction or a horizontal crack can be prevented.

Further, since the grooved cutter wheel can form a scribe line having high permeability, there is a case where a crack penetrates the substrate and completely breaks the substrate as it is, but in this case, the crack is a vertical crack extending in a direction perpendicular to the substrate plane, the direction of the crack is a straight line along the scribe line, and unlike the above-described breaking in an irregular direction, the breaking in which the extending direction of the crack is controlled is preferably performed.

Further, as another advantage of the grooved cutter wheel, "cut suppression" is performed by the grooves, and therefore even if the ridge angle is small, for example, as small as 80 ° to 130 °, particularly as small as about 90 ° to 120 °, even if the load is increased, a trouble that a horizontal crack occurs or a trouble that the substrate is broken in an irregular direction is hard to occur. Therefore, even if the angle of the ridge line is small, which is difficult to form the scribing line, of the (non-groove) common cutter wheel, the scribing line with high permeability can be formed.

On the other hand, the prior art discloses a method for reducing the man-hour for grinding the cutting edge and the cutting edge surface of the cutter wheel to improve the production efficiency, as follows: when two side surfaces are obliquely polished along the outer peripheral surface of a circular plate to form a blade surface having a V-shaped cross section, a two-step inclined surface is formed (see fig. 1(c) of patent document 2), and fig. 4 discloses a cutter wheel as follows: the first inclined surface K1 on the outer peripheral side of the two-stage inclined surface is formed as a blade surface, and is formed with a smaller ridge angle as in the case of a normal cutter wheel, and the second inclined surface K2 not used on the root side of the blade surface is formed such that the virtual ridge angle when the second inclined surface K2 extends to the first inclined surface K1 side is smaller than the ridge angle of the first inclined surface. In this cutter wheel, the wheel having the small ridge angle in which only the second inclined surface is formed is manufactured in advance before the first inclined surface is formed, and the first inclined surface is formed at a desired ridge angle as needed, whereby the cutter wheel having a desired scribing performance can be manufactured. In the cutter wheel, when the cutter wheel rotates on the glass substrate, the first inclined surface forms a scribing line, and the second inclined surface is not contacted with the glass surface.

[ Prior art documents ]

[ patent document ]

[ patent document 1] International publication WO2005/072926

[ patent document 2] Japanese patent laid-open No. Hei 9-188534

Disclosure of Invention

When forming a scribe line on a substrate, it is desirable to eliminate the occurrence of horizontal cracks and the occurrence of fractures in irregular directions, thereby forming a scribe line accompanied by as deep a vertical crack as possible.

The grooved cutter wheel described in patent document 1 is preferable in that a high-permeability scribe line accompanied by a deep vertical crack can be formed as compared with a general cutter wheel.

However, it is sometimes desired to form a high-permeability scribe line accompanied by a deeper vertical crack depending on the thickness or material of the substrate to be processed, and it is more preferable to form a high-permeability scribe line with as little pressure contact load as possible even when a high-permeability scribe line is formed in the same manner, so that the processing quality of the scribe line can be improved.

Accordingly, an object of the present invention is to provide, compared to a conventional grooved cutter wheel:

(1) a cutter wheel that can form a high permeability scribe line accompanied by deeper vertical cracks;

(2) a high permeability scored cutter wheel may be formed even with relatively low crimp loads.

The grooved cutter wheel according to the present invention, which has been completed to achieve the above object, has the following configuration. That is, the blade has a two-step blade surface along the circular outer peripheral edge, and the blade surface includes a first blade surface having a V-shaped cross section in which a ridge having a first ridge angle Φ 1 is formed, and a second blade surface connected to the root side of the first blade surface. The second blade surface is formed such that a virtual second ridge angle φ 2 formed when the second blade surface extends to the first blade surface side is smaller than the first ridge angle φ 1. Further, grooves having a depth reaching the second blade surface are formed periodically along the ridge line of the first blade surface. In addition, the grooved cutter wheel forms a scribing line in a manner that the first blade surface and the second blade surface cut into the processed substrate together when scribing is performed.

According to the present invention, the substrate to be processed is cut by the first blade surface of the first ridge angle Φ 1 to the root and then by the second blade surface of the second ridge angle Φ 2. At this time, since the second ridge angle Φ 2 is smaller than the first ridge angle Φ 1 and the first blade surface having a wide ridge angle is narrowed with respect to the pressure contact surface of the substrate to be processed, the projections between the grooves can be cut to a depth reaching the second blade surface with a smaller pressure contact load than in the case of the prior-type cutter wheel in which only the first blade surface that has not been narrowed is used for scribing. On the other hand, since the grooves having a depth reaching the second cutting edge surface are formed periodically along the cutting edge ridge line, when the cutting is performed to the second cutting edge surface, the grooves function to suppress the cutting, and further cutting is restricted.

[ Effect of the invention ]

According to the present invention, a deeper scribe line can be formed by cutting into the second blade surface, and when the cutting depth is close to the groove depth, further cutting is suppressed, and as a result, the occurrence of irregular directional fracture or horizontal crack due to excessive cutting into the blade surface can be eliminated.

In the above invention, it is preferable that the outer diameter D of the first blade surface of the grooved cutter wheel is set to 1mm to 10mm, particularly 2mm to 5mm, and the first edge angle Φ 1 is set to 100 ° to 160 °, particularly 110 ° to 130 °.

By setting the first edge angle phi 1 to 100 DEG to 160 DEG, when the first blade face is pressed against the substrate, a scribe line can be formed with an appropriate pressing load (preventing the occurrence of horizontal cracks or fractures in irregular directions), and by setting the outer diameter D to 1mm to 10mm, a grooved cutter wheel which is relatively easy to grind in size can be easily formed.

Further, in the above invention, it is preferable that the second ridge angle Φ 2 is 10 ° to 90 °, and the minimum width W of the second blade face is 2 μm to 200 μm, particularly 5 μm to 100 μm.

By setting the minimum width W of the second blade surface (the same as the maximum width of the first blade surface) to 2 to 200 μm and setting the first ridge angle to 100 to 160 °, the depth from the ridge of the first blade surface to the root of the first blade surface becomes about 1 to 100 μm in terms of geometrical relationship.

For example, since a thickness of a general glass substrate used for a liquid crystal panel or the like is about 0.1mm to 1.5mm, if the depth of the first blade surface is in the above range (1 μm to 100 μm), by setting the minimum width W of the second blade surface to an appropriate value within the above range according to the thickness of the glass, it is possible to cut the substrate at the root of the first blade surface (that is, the first blade surface cuts 1 μm to 100 μm), and further, immediately before the second blade surface cuts, prevent the occurrence of horizontal cracks or fractures in irregular directions. Thereafter, the second blade face is further cut, but at this time, the depth of the groove of the cutter wheel reaches the second blade face, and therefore, the depth of the groove becomes larger than the depth of the first blade face, specifically, the depth of the groove becomes deeper than 1 μm when the depth of the first blade face is 1 μm, and the depth of the groove becomes deeper than 100 μm when the depth of the first blade face is 100 μm. When the second blade surface is cut, the groove functions to suppress the cutting, so that it is possible to prevent the second blade surface from being cut excessively to cause horizontal cracks or irregular direction fractures.

Drawings

Fig. 1(a) and (b) are a front view and a side view of a cutter wheel according to an embodiment of the present invention.

Fig. 2 is an enlarged sectional view of the cutter wheel of fig. 1 in the vicinity of the outer periphery thereof.

Fig. 3 is a side view of a cutter wheel according to another embodiment of the present invention.

Fig. 4 is an example of a prior cutter wheel formed with a two-step inclined surface.

[ description of symbols ]

10 cutter wheel

11 wheel body

12 first facet

13 second facet

14 tip of knife

15 groove

16 boundary of the first edge face and the second edge face

2b inclined plane of the 1 st

2c 2 nd inclined plane

Phi 1 first edge angle

Phi 2 second ridge angle

D outside diameter

L first facet depth

Depth of M groove

W minimum width of second facet (maximum width of first facet)

Detailed Description

Hereinafter, the cutter wheel of the present invention will be described in detail based on the drawings. Here, a cutter wheel suitable for processing a glass substrate used for a liquid crystal panel or the like having a thickness of about 0.1mm to 2mm is described as an example, but it is needless to say that the cutter wheel can be applied to a glass substrate having a thickness larger than that. In addition, the present invention is also applicable to a brittle material substrate other than a glass substrate (for example, a ceramic substrate such as LTCC (low-temperature co-fired ceramic), a sapphire substrate, and a semiconductor material).

Fig. 1 is a front view (fig. 1(a) and a side view (fig. 1(b)) showing a structure of a grooved cutter wheel according to an embodiment of the present invention, and fig. 2 is an enlarged sectional view of the vicinity of the outer peripheral edge of the cutter wheel of fig. 1.

The cutter wheel 10 is formed by grinding a wheel body 11 using a disk of cemented carbide or polycrystalline diamond (PCD) into a two-stage blade face including a first blade face 12 and a second blade face 13 connected to the root side of the first blade face 12. Typically, the first facet is formed after the second facet is formed.

The outer diameter D of the wheel body 11 is set to 1mm to 10mm (usually 2mm to 5mm) so as to be easy to use in use and to perform polishing.

The first blade surface 12 is formed by forming a ridge of a first ridge angle Φ 1 on the outer peripheral edge of the wheel body 11, and the tip thereof is a blade edge 14. By setting the first ridge angle φ 1 in the range of 100 to 160 °, defects (occurrence of cracks in irregular directions, damage to a substrate to be processed due to excessive cutting, and the like) when the ridge angle is too narrow or too wide can be prevented.

The second blade surface 13 is formed so as to form a second ridge angle Φ 2 when the second blade surface 13 extends to the first blade surface 12 side. The second ridge angle φ 2 is set smaller than the first ridge angle φ 1. Specifically, by setting the second ridge angle Φ 2 in the range of 10 ° to 90 ° (typically 20 ° to 90 °), unnecessary resistance can be avoided when the second blade face 13 cuts into the first blade face 12 and then the second blade face 13, and the load can be prevented from being dispersed in the horizontal direction.

Further, grooves 15 are periodically formed along the ridge line that becomes the cutting edge 14. The depth M of the flute 15 (the vertical distance from the bottom of the flute 15 to the cutting edge 14) is deeper than the depth L of the first blade surface (the vertical distance from the boundary 16 between the first blade surface 12 and the second blade surface 13 to the cutting edge 14), and therefore the bottom of the flute 15 reaches the second blade surface 13. Thus, when the second blade surface 13 cuts into the glass substrate, the portion of the groove 15 suppresses the cutting of the second blade surface 13. Fig. 1 is a schematic diagram for explaining the outline of each component, and the number of grooves, the groove depth, the groove width, the groove interval (the length of the edge portion (protrusion) between the grooves), and the like are not obtained by scaling down the actual case. For example, in fig. 1, the groove width is equal to or less than the groove interval (the projection length) in appearance, but the groove width is usually set to be longer than the groove interval (the blade edge portion (projection) length), and thus a high-permeability scribe line is easily formed.

In a geometrical relationship with the first ridge angle Φ 1, the minimum width W of the second blade surface 13 (also the maximum width of the first blade surface) is defined as the depth L of the first blade surface. The depth L of the first blade surface must be set to an appropriate value according to the thickness and material of the substrate to be processed. For example, it is assumed that the depth L of the first edge surface is 0.5mm when the thickness of the glass substrate is about 2mm, and the substrate can be cut to the second edge surface 13, but if the depth L of the first edge surface is 0.5mm when the thickness of the glass substrate is about 0.5mm, the substrate is cut before the second edge surface 13 is cut.

Therefore, the minimum width W of the second blade surface 13 must be set to an appropriate value according to the thickness of the substrate to be processed. Specifically, when a glass substrate having a plate thickness of about 0.1mm to 1.5mm is scribed, the minimum width W is set in the range of 2 μm to 200 μm depending on the plate thickness.

Table 1 shows typical examples of the first edge angle Φ 1, the second edge angle Φ 2, the first blade face depth L, the flute depth M, and the minimum width W of the second blade face (the same as the maximum width of the first blade face) when the outer diameter D of the cutter wheel 10 is changed in the range of 2mm to 10 mm.

The first edge angle phi 1 can be arbitrarily set within the range of 100-160 degrees. The second ridge angle Φ 2 is set to an appropriate value in balance with the outer diameter D, and specifically, the second ridge angle Φ 2 becomes smaller as the outer diameter D becomes larger, taking into consideration the thickness of the entire cutter wheel (usually, about 0.3mm to 1 mm).

The smaller the outer diameter D, the deeper the depth L of the first facet may be. The groove depth M may be set to be deeper than the depth L of the first blade surface, and is usually set to 2 to 100 μ M, particularly 5 to 50 μ M, or at least 2 μ M. If the amount is less than this, the dotting impact is difficult to perform, and the cutting is also difficult to be suppressed.

The resistance to cutting of the second edge surface can be reduced by setting the minimum width W of the second edge surface to 200 μm or less even at the maximum.

[ Table 1]

The present invention is not limited to the above-described embodiments, and modifications and changes may be made without departing from the scope of the present invention. For example, fig. 3 is an enlarged view of the vicinity of the outer peripheral edge of the cutter wheel according to another embodiment of the present invention. The same reference numerals are attached to the same portions as those in fig. 1 and 2, and the description thereof is omitted. In this embodiment, the inclined surface 17, which is not a blade edge, is provided on the root side of the second blade surface 13, so that the second blade surface 13 can be made small and the polishing process can be simplified.

[ industrial applicability ]

The invention can be used for forming a scribing line with high permeability on a brittle material substrate represented by a glass substrate without generating horizontal cracks.

Claims (7)

1. A cutter wheel for a brittle material substrate, characterized in that: a second blade surface having a V-shaped cross section formed with a ridge having a first ridge angle φ 1 and connected to the root side of the first blade surface,

the second blade surface is formed so that a virtual second ridge angle phi 2 formed when the second blade surface extends to the first blade surface side is an angle smaller than the first ridge angle phi 1,

grooves are formed periodically along the ridge line of the first blade surface to a depth of the second blade surface

The first blade surface and the second blade surface are cut into the substrate to be processed together to form a scribing line.

2. The cutter wheel of claim 1, wherein:

the outer diameter D of the first blade surface is 1 mm-10 mm, and the first edge angle phi 1 is 100-160 degrees.

3. The cutter wheel of claim 2, wherein:

the second edge angle phi 2 is 10-90 degrees, and the minimum width W of the second edge surface is 2-200 mu m.

4. The grooved cutter wheel of claim 3, wherein:

the depth of the groove is 2-50 μm.

5. The grooved cutter wheel of claim 1, wherein:

the minimum width of the second blade surface is 2-200 mu m.

6. A method for scribing a brittle material substrate, comprising:

the cutter wheel according to claim 1 is pressure-bonded to a surface of a brittle material substrate and rotated.

7. A scoring method according to claim 6, wherein:

and pressing the cutter wheel on the brittle material substrate in a cutting mode until the second blade surface is reached.