JP7195701B2 - How to fix a bite tool - Google Patents

Description

TECHNICAL FIELD The present invention relates to a tool tool repairing method for removing defects on the cutting edge of a cutting edge of a tool tool containing diamond.

A plurality of devices such as ICs (Integrated Circuits) and LSIs (Large Scale Integrated Circuits) are formed on the front surface of a wafer, and the back side of the wafer is ground to thin the wafer. device chip can be formed. The formed device chip is mounted on an electronic device such as a mobile phone or a personal computer.

In recent years, for example, a mounting technique called flip-chip bonding has been put to practical use in order to achieve thinning and miniaturization of device chips. In this mounting technique, a plurality of metal protrusions called bumps having a height of about 10 μm to 100 μm are formed on the surface of the device chip. When the device chip is mounted on the wiring board, these bumps are made to face the electrodes formed on the wiring board and directly bonded.

Furthermore, bumps are formed directly on the surfaces of a plurality of devices formed on a wafer, and the bumps are sealed together with the wafer surface with a sealing material. After that, the wafer is divided for each device to form device chips. The technology has been put into practical use (see Patent Document 1, for example). This technology is called WL-CSP (Wafer-level Chip Size Package).

In these techniques, since the heights of the plurality of bumps are uneven, it is difficult to uniformly bond all the bumps to the respective electrodes of the wiring substrate to be mounted. Therefore, a processing method has been put into practical use, in which a cutting tool having a cutting edge containing diamond is attached to a cutting tool to thin the encapsulant covering the surface of the device chip and to align the height of the bumps (for example, See Patent Document 2).

Japanese Unexamined Patent Publication No. 2001-7135 JP-A-2000-173954

Since the sealing material that covers the surface of the device chip is hard, cutting the sealing material with a cutting tool tends to cause small defects on the tip of the cutting edge. If a cutting tool with a defective cutting edge is used to continuously cut a work piece with a cutting tool, the surface of the work piece may be roughened or cracks may occur in the work piece. That is, the cutting tool cannot properly process the workpiece.

Therefore, when a defect occurs in the cutting edge of the cutting edge of the cutting tool, the cutting by the cutting tool is stopped and the cutting tool is replaced. After changing the cutting tool, the cutting tool can again properly machine the workpiece. However, the cutting of the workpiece cannot be performed while the cutting tool is replaced, and the cost of the new cutting tool reduces the time and cost efficiency of cutting the cutting tool with the cutting tool. .

The present invention has been made in view of such problems, and an object of the present invention is to provide a cutting tool capable of removing defects formed on the cutting edge of a cutting edge of a cutting tool in a state in which the cutting tool is attached to a cutting tool. The object is to provide a tool modification method.

According to one aspect of the present invention, there is provided a cutting tool tool repairing method for removing a defect formed on the cutting edge of a cutting edge of a cutting tool containing diamond, comprising: a preparation step of preparing a substrate; and after the preparation step, cutting the cutting edge of the cutting edge into the substrate for correction, cutting the substrate for correction with the bit tool, and consuming the cutting edge. and a cutting edge repairing step of removing defects formed on the cutting edge , wherein the substrate for repair is a silicon substrate .

In one aspect of the present invention, a correction substrate is prepared for correcting the cutting edge of a cutting edge of a cutting tool. The correction substrate is, for example, a silicon substrate. Then, the tip of the cutting edge of the bit tool is cut into the substrate for correction, and the substrate for correction is cut by the bit tool. The cutting edge is then worn away from the cutting edge.

This is probably because a chemical reaction occurs between the diamond and the silicon when the tool tool containing diamond in the cutting edge and the silicon substrate as the substrate for correction come into contact with each other. Alternatively, it is considered that the diamond is carbonized by processing heat generated by cutting with a cutting tool. Alternatively, another possibility is that plasma is generated at the point of contact between the cutting edge of the cutting edge and the repair substrate, and the plasma carbonizes the diamond or breaks the C—C bonds of the diamond.

If the cutting edge of the cutting edge is actively worn by cutting the substrate for repair with a cutting tool that has a defect on the cutting edge, the location where the defect was formed disappears and a new cutting edge with no defect is formed. It is formed. Therefore, the cutting tool can cut the workpiece again with the cutting tool. At this time, since there is no need to replace the cutting tool, the time for stopping the operation of the cutting tool can be shortened. Also, the life of the tool can be extended. As a result, the cost of cutting with a cutting tool is reduced and the processing efficiency is dramatically increased.

Therefore, the present invention provides a method for correcting a cutting tool that can remove defects on the cutting edge of the cutting edge of the cutting tool while the cutting tool is attached to the cutting apparatus.

FIG. 4 is a perspective view schematically showing a correction substrate; FIG. 4 is a side view schematically showing a cutting edge correction step; It is a perspective view which shows a cutting tool typically. FIG. 4(A) is an enlarged side view schematically showing a cutting tool with a defect on the cutting edge, and FIG. 4(B) is an enlarged side view schematically showing the cutting tool with the defect removed from the cutting edge. is.

Embodiments of the present invention will be described with reference to the accompanying drawings. First, a cutting tool using a cutting tool modified by the cutting tool modification method according to the present embodiment will be described. A cutting tool has a function of cutting a workpiece with a cutting tool. FIG. 2 shows a side view of the cutting tool 2. As shown in FIG.

As shown in FIG. 2 , the cutting tool 2 has a chuck table 4 . The chuck table 4 includes a porous member (not shown) exposed on the upper surface side and a suction source (not shown) connected to the porous member, and the upper surface of the chuck table 4 holds a workpiece. It becomes the holding surface 4a. Also, the chuck table 4 is movable in a direction parallel to the holding surface 4a.

The tool cutting device 2 includes a tool cutting unit 6 above the chuck table 4 for cutting a workpiece with a tool. The cutting tool unit 6 includes a spindle 8 extending in a direction perpendicular to the holding surface of the chuck table 4 and a disk-shaped wheel mount 8 a fixed to the lower end of the spindle 8 . An annular bite wheel 10 having a bite tool 12 attached to its outer periphery is fixed to the lower surface of the wheel mount 8a.

When the spindle 8 is rotated around an axis perpendicular to the holding surface 4a of the chuck table 4, the bite tool 12 attached to the bite wheel 10 rotates. The cutting tool 12 is mounted at a predetermined position on the cutting tool wheel 10 so that the radius of the rotation orbit of the cutting tool 12 at this time is larger than the diameter of the workpiece.

FIG. 3 is a perspective view schematically showing the cutting tool 12. FIG. The cutting tool 12 includes a support 14 that supports a cutting edge 16 made of diamond, and the cutting edge 16 fixed near the lower end of the support 14 . The upper part of the support 14 is fixed to the lower surface of the bite wheel 10 .

When cutting a workpiece with a tool, the tool cutting unit 6 is lowered and the tool 12 is rotated so that the cutting edge is positioned at a predetermined height determined by the depth of machining of the workpiece. Then, the chuck table 4 is moved in a direction parallel to the holding surface 4 a so as to pass below the cutting tool unit 6 . When the cutting edge 16a of the cutting edge 16 of the rotating cutting tool 12 comes into contact with the workpiece held on the chuck table 4, the workpiece is cut by the cutting tool.

A workpiece processed by the cutting tool 2 is, for example, a wafer having a plurality of devices such as ICs and LSIs formed on its surface. By dividing the wafer into devices, individual device chips are formed. The device chip is mounted on a predetermined wiring board or the like. In recent years, a technology has been developed in which a plurality of metal bumps are formed on the surface of a device chip in advance, and when the device chip is mounted on the wiring board, these bumps are directly bonded to the electrodes formed on the wiring board by facing them. has been put into practical use.

Bumps are formed, for example, on the electrodes of each device formed on the front side of the wafer before the wafer is divided. Then, the front side of the wafer is covered and sealed with a sealing material. Here, since the heights of the plurality of bumps are uneven, it is difficult to uniformly bond all the bumps to the respective electrodes of the wiring board. Therefore, the cutting tool 2 is used to thin the sealing material covering the surface of the wafer and to align the heights of the bumps.

Since the sealing material covering the surface of the wafer has a high hardness, when cutting the sealing material with the bit tool 12, the cutting edge 16a of the cutting edge 16 of the bit tool 12 tends to have small defects. FIG. 4(A) is a side view schematically showing an enlarged cutting edge 16 having a defect 16b on the cutting edge 16a.

If the tool bit tool 12 with the cutting edge 16a of the cutting edge 16 having the defect 16b is used to continue cutting the wafer with the tool bit, the tool cutting device 2 cannot properly process the wafer, and cracks may occur in the wafer. . In addition, irregularities may be formed on the surface of the wafer to be processed due to the defects 16b.

Therefore, when a defect 16b occurs in the cutting edge 16a of the cutting edge 16 of the cutting tool 12, and the cutting tool 12 is in a state where the cutting tool 12 cannot appropriately cut the workpiece, the method for correcting the cutting tool according to the present embodiment is performed. corrects the bit tool 12 by A correction substrate is used for correcting the bit tool 12 . FIG. 1 is a perspective view schematically showing a correction substrate 1. FIG.

A silicon substrate, for example, is used as the substrate 1 for repair in repairing the bit tool 12 whose cutting edge 16 contains diamond. Alternatively, a substrate made of a material such as hard resin or rubber may be used as the correction substrate 1 . A case where a silicon substrate is used as the correction substrate 1 will be described below as an example. The correction substrate 1 is, for example, a silicon substrate that can be used when manufacturing a device chip on which an IC, LSI, or the like is mounted.

Next, each step of the tool tool correction method according to the present embodiment will be described. In the method for correcting the cutting tool, first, a preparatory step of preparing the correction substrate 1 for correcting the cutting edge 16a of the cutting edge 16 is performed.

In the preparatory step, first, the chuck table 4 is moved to a position away from directly below the cutting tool unit 6, and the correction substrate 1 is placed on the holding surface 4a of the chuck table 4 of the cutting tool 2. As shown in FIG. At this time, the cutting surface 1a capable of correcting the cutting edge 16a of the cutting edge 16 of the cutting tool 12 of the correction substrate 1 faces upward, and the surface 1b not used for correcting the cutting edge 16a faces the holding surface 4a of the chuck table 4. Then, the suction source of the chuck table 4 is operated to hold the correction substrate 1 on the chuck table 4 by suction.

In the cutting tool repairing method according to the present embodiment, the cutting edge repairing process for removing the defect 16b formed on the cutting edge 16a is performed after the preparation process. FIG. 2 is a side view schematically showing the cutting edge correction process. In the cutting edge correction process, first, the cutting tool unit 6 is positioned at a predetermined height position. Then, the chuck table 4 is moved in a direction parallel to the holding surface 4 a so as to pass below the cutting tool unit 6 while rotating the spindle 8 to rotate the cutting tool 12 . is cut with a bite.

The predetermined height position of the cutting tool 6 is, for example, the height position at which the cutting edge 16 of the cutting tool 12 cuts the correction substrate 1 to a depth of 2 μm to 5 μm. When the cutting edge 16a of the cutting blade 16 is cut into the correction substrate 1, the cutting substrate 1 is cut by the cutting tool 12 and the cutting edge 16a is worn.

The reason why the cutting edge 16a wears out is thought to be that a chemical reaction occurs between the diamond and silicon when the cutting edge 16 contains diamond and the silicon substrate, which is the repair substrate 1, comes into contact with each other. be done. Alternatively, it is considered that the diamond is carbonized by processing heat generated by cutting with a cutting tool. Alternatively, another possibility is that plasma is generated at the contact point between the cutting edge 16a and the repair substrate 1, and the plasma carbonizes the diamond or cuts the CC bonds of the diamond.

In any case, it has been confirmed that cutting the correction substrate 1 with the bit tool 12 causes the cutting edge 16a of the bit tool 12 to wear out. As the cutting edge 16a wears, the portion of the cutting edge 16a having the defect 16b is also worn out. Furthermore, the cutting of the correction substrate 1 is continued until all the defects 16b formed on the cutting edge 16a disappear. Then, the defect 16b is removed from the cutting edge 16a, and a state suitable for cutting the workpiece with a cutting tool is obtained.

FIG. 4(B) is an enlarged schematic side view of the cutting edge 16 from which the defect 16b has been removed. FIG. 4B shows the position 16c of the cutting edge 16a before the cutting edge correction step. In the cutting edge repair process, the cutting edge 16a is actively worn to such an extent that the defect 16b is removed. After that, when the correction substrate 1 is released from the chuck table 4 by suction and held, and the correction substrate 1 is removed, the cutting tool 2 is in a state suitable for cutting the workpiece.

That is, when the cutting edge 16a of the cutting edge 16 is actively worn by cutting the repair substrate 1 with the cutting tool 12 having the defect 16b on the cutting edge 16, the location where the defect 16b is formed disappears. Thus, a new cutting edge 16a without defects is formed. At this time, since there is no need to replace the cutting tool 12, the time for stopping the operation of the cutting tool 2 can be shortened. Also, the life of the bite tool 12 can be extended. As a result, the cost of cutting with a cutting tool is reduced and the processing efficiency is dramatically increased.

It should be noted that the present invention is not limited to the description of the above embodiments, and can be implemented with various modifications. For example, in the above embodiment, the case where the cutting edge 16a of the cutting edge 16 of the cutting tool 12 is corrected while attached to the cutting tool 2 has been described, but one aspect of the present invention is not limited to this. For example, the cutting tool 12 having the defect 16b is removed from the cutting tool cutting device 2, the cutting tool 12 is attached to a dedicated cutting tool repairing device configured similarly to the cutting tool cutting device 2, and the substrate for correction is attached to the cutting tool repairing device. 1 may be installed to modify the bit tool 12 .

Further, in the above embodiment, the case of correcting the cutting edge 16a of the cutting tool 12 including the diamond in the cutting edge 16 has been described, but one aspect of the present invention is not limited to this. For example, in one aspect of the present invention, the cutting edge 16a of the cutting edge 16 of a cemented carbide tool containing cobalt-containing tungsten carbide (WC—Co) may be modified. In this case, for the correction substrate 1, a material suitable for correction of cemented carbide cutting tools is used.

The structures, methods, and the like according to the above-described embodiments can be modified as appropriate without departing from the scope of the object of the present invention.

1 Correction board 1
1a, 1b surface 2 tool cutting device 4 chuck table 4a holding surface 6 tool cutting unit 8 spindle 8a wheel mount 10 tool wheel 12 tool tool 14 support 16 cutting edge 16a cutting edge 16b defect 16c cutting edge before performing the cutting edge correction process Position of

Claims (1)

A method for correcting a cutting tool for removing defects on the cutting edge of a cutting edge of a cutting edge containing diamond, comprising:
a preparation step of preparing a correction substrate for correcting the cutting edge;
After the preparation step, the cutting edge of the cutting edge is cut into the substrate for repair, and the substrate for repair is cut by the cutting tool with a bite, and the defect formed on the cutting edge is removed by wearing the cutting edge. A cutting edge correction step to remove;
with
A method for correcting a cutting tool, wherein the substrate for correction is a silicon substrate .

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