JP2017013488A - Cutter wheel and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a single crystal diamond cutter wheel having an irregularity-nonexistent smooth edge inclined plane and stably usable over a long period, and a manufacturing method thereof.SOLUTION: A cutter wheel A is composed of single crystal diamond having an edge part 2 on an outer peripheral surface, and the edge part 2 is composed of bilaterally symmetrical three-stage inclined planes 2a, 2b and 2c and a ridgeline 2d formed in an intersection between the left-right inclined planes 2c and 2c of the uppermost stage, and an inclination angle of the respective inclined planes 2a-2c is constituted so that the upper stage inclined plane is gently formed more than the lower stage inclined plane and the uppermost stage inclined plane 2c and the ridgeline 2d form a substantial edge, and the uppermost stage inclined plane 2c is formed so that a width L1 in its thickness direction is a half or less of a thickness of a disk-like body 1, and surface roughness becomes 0.03 μm or less in arithmetic average roughness.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a cutter wheel (also referred to as a scribing wheel) used for processing or dividing a scribe line (cut groove) in a brittle material substrate and a method for manufacturing the same. In particular, the present invention is suitable for processing or dividing a scribe line on a brittle material substrate that is harder than an amorphous glass substrate, such as a ceramic substrate such as alumina, HTCC, or LTCC, a sapphire substrate, or a silicon substrate. The present invention relates to a cutter wheel made of single crystal diamond and a method for manufacturing the same.

  In processing to cut a brittle material substrate, a scribe line is formed on the substrate surface using a cutter wheel, and then the substrate is bent by applying an external force from the back side along the scribe line. The method to do is generally known, for example, disclosed in Patent Document 1.

  As a cutter wheel for processing a scribe line on a brittle material substrate, a cutter wheel having a V-shaped cutting edge on a circumferential surface is used. The cutter wheel is generally made of cemented carbide or polycrystalline diamond sintered body, but recently it is made of single crystal diamond for scribing ceramic substrates, sapphire substrates, silicon substrates, etc., which are harder than glass substrates. Cutter wheels are attracting attention.

  In order to form a V-shaped cutting edge on the circumferential surface of the cutter wheel, as shown in FIG. 3, the shaft 4 of the polishing apparatus is inserted into the bearing hole 3 of the disk-shaped body 101 as a material, and the disk-shaped body. Is rotated, and both side edges of the circumferential surface are polished obliquely by the polishing grindstone 5 to form a V-shaped cutting edge composed of left and right slopes and ridge lines.

  In the process of cutting a brittle material substrate such as a glass substrate, after processing the scribe line with a cutter wheel, the substrate is split along the scribe line by applying external force to the substrate, but the cutting edge slope of the cutter wheel is not sufficiently polished. If unevenness remains on the substrate, scratches remain on the divided end surface of the substrate when the substrate is divided, and the strength of the end surface of the substrate decreases. Also, if the cutter wheel has irregularities on the blade tip slope, the resistance during scribing increases, the blade tip is chipped, or wear progresses, leading to a reduction in the service life. Therefore, it is required to form the blade edge slope on a smooth surface without irregularities. It is preferable that the surface roughness of the cutting edge slope is 0.03 μm or less in terms of arithmetic average roughness (Ra).

Japanese Patent No. 3787489

  However, in order to cut both side edges of the circumferential surface of the disk into a V-shaped cutting edge, there are many polishing areas to be scraped off, and therefore, a coarse grinding wheel for coarse polishing must be used. . Therefore, after machining into a V shape, it is necessary to finish and polish the cutting edge slope with a fine grinding grindstone, but since there are large irregularities on the cutting edge slope after processing with a coarse grinding stone, a fine grinding sandstone It takes time to polish the surface to a preferable surface roughness with the use of, and the replacement frequency of the polishing grindstone is increased and the cost is increased. In addition, since the tip of the cutter wheel has a substantial edge at the tip ridge line that bites into the brittle material substrate, it is only necessary to finish only the tip of the tip that performs this work with the desired surface roughness. In the method, since the entire region of the cutting edge slope is finished and polished, a wasteful portion is generated. In particular, when processing a cutter wheel consisting of only single-crystal diamond that has high hardness and is susceptible to the effects of multiple crystal orientations appearing on the surface, the uneven edge of the blade edge is uniformly finished and polished to the desired surface roughness on the entire circumference. That is a very difficult task.

  Then, in view of the said subject, this invention has a smooth cutting edge slope without an unevenness | corrugation, and it aims at providing the cutter wheel made from a single crystal diamond which can be used stably over a long term, and its manufacturing method. .

In order to solve the above problems, the present invention takes the following technical means. That is, the cutter wheel of the present invention is a cutter wheel made of single-crystal diamond having a cutting edge portion on the outer peripheral surface, and the cutting edge portion is an intersection of a three-stage slope that is symmetric with the left and right slopes of the uppermost stage. The slopes of the three slopes are formed such that the upper slope is gentler than the lower slope, and the uppermost slope and the ridge line are subject to scribing. It is configured to form a substantial cutting edge that bites into the brittle material substrate, the width in the thickness direction of the uppermost slope portion is less than half of the thickness of the disk-shaped body, and the surface roughness of the uppermost slope surface However, it was set as the structure currently formed so that it may become 0.03 micrometer or less by arithmetic mean roughness.
Here, it is preferable that the angle at which the left and right slopes of the uppermost stage intersect is 100 to 150 °.

  The present invention also features the following cutter wheel manufacturing method. That is, the manufacturing method of the cutter wheel of the present invention comprises a cutting edge consisting of a symmetric three-stage slope and a ridge formed at the intersection of the uppermost slope on the outer peripheral surface, and each of the three-stage slopes is A method of manufacturing a cutter wheel made of single crystal diamond formed so that the upper slope has a gentler inclination angle than the lower slope, by removing both side edges of the circumferential surface of the circular body. Formed by the secondary processing step, the secondary processing step of processing a part of the lowermost slope formed by the primary processing step to form the second slope, and the secondary processing step And a tertiary processing step of forming a top slope by processing a part of the slope of the second stage, and in the tertiary processing step, the surface roughness of the top slope is 0. Processed to be 03 μm or less, Percentage uppermost slant portion to be processed in the processing step occupies the thickness of the disc-shaped body was set to be processed to be equal to or less than half of the thickness of the disc-shaped body.

  According to the cutter wheel of the present invention, since the slope of the blade edge portion is formed by a three-step slope, when the slope is processed, it can be processed in three steps sequentially from the lower slope to the upper stage. Therefore, by changing to a grinding wheel with finer grain size in the order of the processing steps, the surface irregularities can be reduced sequentially from the first step slope to the second step and third step slopes. It is possible to easily process the uppermost slope, which is a sharp cutting edge slope, to a desired surface roughness using a fine grinding grindstone for finishing. In addition, since the width of the uppermost slope is less than half of the thickness of the disc-shaped body, when the uppermost slope is polished with a finishing grinding wheel, the entire width of the conventional blade edge slope is polished. Compared to this, the polishing area is greatly reduced, and finish polishing can be performed quickly and without waste. Thereby, it is possible to easily obtain a cutter wheel made of a single crystal diamond having a smooth cutting edge slope without unevenness and having a long service life with little blade spillage.

In addition, according to the method for manufacturing a cutter wheel of the present invention, a blade edge portion having a three-step slope is processed through three steps of primary, secondary, and tertiary, but at this time, from the first-step slope, The second and third slopes are sequentially processed so that the surface irregularities become smaller. Therefore, in the end, the uppermost third slope, which is a substantial cutting edge slope, can be easily processed to a desired surface roughness using a fine grinding grindstone for finishing.
Also, in the tertiary processing process, only the third step slope, which is less than half the thickness of the disk-shaped body, is finished to the desired surface roughness, so the entire width of the tip slope is processed as before. Compared to this, the processing area is greatly reduced, and finishing can be performed quickly without waste. This advantage is particularly noticeable in the processing of a cutter wheel made of only single crystal diamond that is hard and susceptible to different crystal orientations. Thereby, it is possible to efficiently produce a cutter wheel made of a single crystal diamond that has a smooth cutting edge slope with no irregularities on the entire circumference, has little blade spillage, and has a long service life.

In the said invention, it is preferable that the maximum height roughness of a ridgeline shall be 0.3 micrometer or less. More preferably, the maximum height roughness of the ridgeline is 0.1 μm or less, and further 0.05 μm or less.
This was not a problem when the material of the cutter wheel was a polycrystalline diamond sintered body. However, in recent years, a cutter wheel made of single crystal diamond has cracks due to fine scratches (cracks) on the surface. It has been found that it has a tendency to proceed. In particular, when single crystal diamond is processed into a disk shape and a cutting edge is formed on the outer periphery thereof, since it is affected by different crystal orientations periodically on the circumference, fine flaws (cracks) are generated at specific locations. Easy to appear. Therefore, not only the arithmetic average roughness (Ra) but also the value of the maximum height roughness (Rz) of the ridge line should be reduced to the same extent at a plurality of locations affected by different crystal orientations. Was found to be effective in preventing cracking. That is, the maximum height roughness (Rz) of the ridge line, which is the sum of the maximum value of the peak height of the ridge line and the maximum value of the valley depth, is processed so that there is no portion on the outer periphery that is larger than the above value. By reducing local unevenness that is difficult to appear in the arithmetic average roughness (Ra) value of the cutter wheel surface, the trouble that the cutter wheel receives local and concentrated load at the time of scribing is reduced. Will be able to.

The front view which shows the cutter wheel of this invention, a side view, and the enlarged view of a blade-tip part. Explanatory drawing which shows the manufacturing process of the cutter wheel of this invention. Explanatory drawing which shows the primary grinding | polishing process in the manufacturing method of the cutter wheel of this invention. The figure explaining the effect of this invention.

Below, the cutter wheel of this invention and its manufacturing method are demonstrated in detail based on FIGS. 1-3.
Fig.1 (a) is a front view which shows the cutter wheel A which concerns on this invention, FIG.1 (b) is a side view, FIG.1 (c) is an enlarged view of a blade edge | tip part. The cutter wheel A is made of only single crystal diamond, and a blade edge portion 2 is provided on the outer peripheral surface of a disc-shaped body 1 having a bearing hole 3 at the center. In this embodiment, the cutter wheel A is formed so that the diameter D of the cutter wheel A is 2 mm, the thickness t is 650 μm, and the angle at which the third (uppermost) slope intersects is 120 °.

The blade edge portion 2 of the cutter wheel A is composed of three steps of slopes 2a, 2b, 2c formed symmetrically and a ridge line 2d formed at the intersection of the uppermost steps 2c, 2c. The slopes of these slopes 2a, 2b and 2c are formed such that the upper slope is gentler than the lower slope. In this embodiment, the angle α1 at which the left and right slopes 2a and 2a of the first stage (the lowest stage) intersect is formed at 90 to 140 °, preferably 100 to 140 °, and the left and right slopes 2b and 2b of the second stage intersect. The angle α2 is formed at 95 to 145 °, preferably 105 to 145 °, and the angle α3 at which the left and right inclined surfaces 2c and 2c intersect at the third step (uppermost step) is formed at 100 to 150 °, preferably 110 to 150 °. Has been. The third slopes 2c and 2c and the ridge line 2d where these slopes cross each other serve as a substantial cutting edge that bites into the brittle material substrate during scribing. Therefore, the angle α3 at which the inclined surfaces 2c and 2c intersect is the blade edge angle. Here, the angle difference between the angle α3 where the third (uppermost) slopes 2c and 2c intersect and the angle α2 where the second slopes 2b and 2b intersect is 5 to 10 °, and the second slopes 2b and 2b. It is preferable that the angle difference between the angle α2 at which the angle α2 intersects and the angle α1 at which the first (lowermost) slopes 2a, 2a intersect is 5 to 10 °. By setting such an angle difference, it is possible to accurately and reliably form the inclined surface and the ridge line while minimizing the amount removed by processing.
The width L1 along the slope from the ridge line of the third stage slopes 2c and 2c, which is the substantial cutting edge, is preferably formed to be 10 to 50 μm on one side in the cutter wheel A having a diameter of 2 mm and a thickness of 650 μm. . When the angle at which the third-stage (topmost) slope intersects is 120 ° and the width L1 along the slope is 50 μm on one side, the width in the thickness direction including the right and left slopes of the third stage is about 80 μm. .

Next, the manufacturing method of the cutter wheel A is demonstrated based on FIG. 2 and FIG.
FIG. 2A shows the disc-like body 101 before cutting edge processing. The disk-like body 101 is circular when viewed from the side and has a flat outer peripheral surface, and a through-hole bearing hole 3 is provided at the center. The thickness t of the disc-like body 101 is 650 μm, which is the same as the thickness of the completed cutter wheel A.

As shown in FIG. 3, the disk-shaped body 101 has a bearing hole 3 inserted into a rotating shaft 4 of the polishing apparatus to attach the disk-shaped body 101, and the polishing wheel 5 is rotated while rotating the disk-shaped body 101. By pressing against the side edge portion of the outer peripheral surface of the disk-shaped body 101, the processing of the first slope 2a, that is, the primary processing step is performed. In this step, first one inclined surface 2a is processed, and then the disk-shaped body 101 is reversed to process the other inclined surface 2a. Thereby, the disk-shaped body 102 in which the cutting edge slope is formed only by the slope 2a as shown in FIG. 2B is formed.
In the primary processing step, since the region S1 to be removed is large, that is, the processing region is large, a polishing grindstone with a coarse particle size, for example, coarse polishing with a particle size of 400 to 1000, preferably 600 to 900, when processed by polishing. Polish using a grindstone.

Next, a secondary processing step of processing the upper part of the first step slope 2a processed in the previous primary processing step to form the second step slopes 2b and 2b by the same method as described above is performed. As a result, as shown in FIG. 2 (c), a disc-like body 103 having a two-stage cutting edge slope formed by the first-stage slope 2a and the second-stage slope 2b is formed. In this case, the width W2 along the inclined surface of the second slopes 2b and 2b is preferably 30 to 80 μm on one side according to the angle.
In this secondary processing step, the region S2 to be removed by processing, that is, the processing region is remarkably smaller than the processing region S1 of the primary processing step. Therefore, when processing by polishing, the polishing grindstone used in the primary processing step It can grind | polish using a grinding whetstone with a finer particle size, for example, a grinding whetstone having a particle size of 2000 to 8000, preferably 3000 to 5000. As a result, the second slope 2b is finely processed with an uneven surface smaller than the first slope 2a.

Next, as shown in FIG. 2 (d), a tertiary processing step is performed in which the upper portion of the second slope 2b processed by the secondary processing process is processed to form third slopes 2c, 2c. The disc-shaped body 1 is completed. In this case, the width W1 along the slope from the ridgeline of the third slopes 2c and 2c is preferably 10 to 50 μm. At this time, the width L1 in the thickness direction of the left and right slope portions of the third stage is set to be equal to or less than half the thickness t of the disc-shaped body 1. The third slopes 2c and 2c and the ridge line 2d formed at the intersection of these slopes form a substantial cutting edge that bites into the brittle material substrate during scribing.
In the tertiary processing step, the area S3 removed by the processing is further reduced as compared with the processing region S2 in the secondary processing step, and the unevenness on the surface of the second slope 2b to be scraped is reduced by the previous secondary processing step. It has become. For this reason, when processing by polishing, a polishing grindstone for finishing with a finer particle size than that used in the secondary processing step, for example, a grindstone having a particle size of 10,000 to 30,000 can be used. Thus, it is possible to easily polish to a desired surface roughness, that is, an arithmetic average roughness (Ra) defined by JIS0601: 2013 of 0.03 μm or less, preferably 0.01 μm.

  Similarly, the maximum height roughness (Rz) specified in JIS0601: 2013 is measured, and the maximum height roughness (Rz) is 0.3 μm or less, preferably 0.1 μm or less, more preferably 0.05 μm or less. To be. Thereby, it is possible to make it difficult to generate cracks due to fine flaws (unevenness) on the ridgeline. In this process, cracks are less likely to occur as the arithmetic average roughness (Ra) and the maximum height roughness (Rz) are reduced. However, since the difficulty of the process increases accordingly, the roughness is related to the processing cost. The accuracy of the is to be determined.

  As described above, in the present invention, the cutting edge portion 2 having a three-step slope is processed through three-step processing steps of primary, secondary, and tertiary. At this time, by changing the polishing grindstone to a finer grain size in the order of the processing steps, the processing is performed so that the unevenness of the surface is gradually reduced from the first-stage slope 2a to the second-stage slope 2b and further to the third-stage slope 2c. The Therefore, in the tertiary processing step of processing the third-stage inclined surface 2c that is a substantial cutting edge inclined surface, it is possible to easily process to a desired surface roughness using a polishing grindstone for fine finishing. Further, in the tertiary processing step, only the third-stage slope 2c, which is a substantial cutting edge slope, is finished to the desired surface roughness, so that the conventional cutting edge slope as shown in FIG. 4 (b). Since the width L1 of the slope 2c shown in FIG. 4 (a) is less than half the thickness t of the disc-shaped body 1 as compared with the width L of FIG. This advantage is particularly noticeable in the polishing of a cutter wheel made of only hard single crystal diamond.

As mentioned above, although the typical Example of this invention was described, this invention is not necessarily specified to said embodiment. For example, the present invention can be applied to cutter wheels having a diameter of 0.8 to 3 mm including those having a diameter of 2 mm shown in the above embodiments. In addition, although the intersection angle α3 of the third-stage slope 2c, which is a substantial blade edge angle, is 120 ° in the present embodiment, it can be implemented within a range of 100 to 150 °.
In this embodiment, the processing region is formed by polishing in the primary processing step, the secondary processing step, and the tertiary processing step. However, the processing region may be formed by other processing methods. For example, electric discharge machining can be used for laser processing or single crystal diamond doped with impurities such as boron and phosphorus to have conductivity. In the primary machining process having a large machining area, machining time can be shortened by using laser machining or electric discharge machining. On the other hand, in order to reduce the surface roughness after processing, the tertiary processing is preferably performed by polishing.
Others The present invention can be appropriately modified and changed within the scope of achieving the object and without departing from the scope of the claims.

  The present invention relates to a cutter wheel made of single crystal diamond used for processing or dividing a scribe line on a brittle material substrate harder than an amorphous glass substrate such as a ceramic substrate, a sapphire substrate, or a silicon substrate. Applies to

A Cutter wheel L1 Width of the third step (top) slope α3 Intersection angle of the third step slope 1 Disc-shaped body 2 Blade edge 2a First step (bottom step) slope 2b Second step slope 2c Third step Eye slope 2d Ridge line 3 Bearing hole

Claims (8)

A cutter wheel made of single-crystal diamond having a cutting edge on the outer peripheral surface,
The blade edge part is composed of a three-step symmetrical slope and a ridge line formed at the intersection of the uppermost left and right slopes,
The inclination angle of each of the three slopes is formed such that the upper slope is gentler than the lower slope,
The uppermost slope and the ridgeline are configured to form a substantial cutting edge that bites into a brittle material substrate to be scribed,
The width of the uppermost slope portion in the thickness direction is less than half of the thickness of the disk-shaped body, and the surface roughness of the uppermost slope surface is 0.03 μm or less in terms of arithmetic average roughness. Cutter wheel that has been. The cutter wheel according to claim 1, wherein an angle at which the left and right slopes of the uppermost stage intersect is 100 to 150 °. The cutter wheel according to claim 1 or 2, wherein a maximum height roughness of the ridge line is 0.03 µm or less. The cutter wheel according to claim 3, wherein the maximum height roughness of the ridge line is 0.01 μm or less. The outer peripheral surface is provided with a cutting edge part consisting of a symmetrical three-stage slope and a ridge formed at the intersection of the uppermost slope, and each of the three slopes has an upper slope that is gentler than the lower slope. A method of manufacturing a cutter wheel made of single crystal diamond formed to have an inclination angle,
A primary processing step in which both side edges of the circumferential surface of the circular body are removed to form a bottom slope;
A secondary processing step of processing a part of the lowermost slope formed by the primary processing step to form a second slope;
It consists of a tertiary processing step of processing a part of the second step slope formed by the secondary processing step to form the uppermost slope,
In the tertiary processing step, the surface roughness of the uppermost slope is processed so that the arithmetic average roughness is 0.03 μm or less,
A method for manufacturing a cutter wheel, wherein the uppermost slope portion processed in the tertiary processing step is processed so that a width in a thickness direction is not more than half of a thickness of a disk-shaped body. The method for manufacturing a cutter wheel according to claim 5, wherein in the tertiary processing step, the processing is performed so that an angle at which the left and right slopes of the uppermost stage intersect each other is 100 to 150 °. The method for manufacturing a cutter wheel according to claim 5 or 6, wherein a maximum height roughness of the ridge line is 0.03 µm or less. The method for producing a cutter wheel according to claim 7, wherein the maximum height roughness of the ridge line is 0.01 μm or less.

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