JPH0994820A - Method for detecting abrasion amount of blade and apparatus for manufacturing semiconductor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correct the amount of cutting by the abrasion of a blade by a method in which after the recessing of a material to be processed the distance in the diameter direction from a prescribed position to the peripheral end of the blade is measured again, and the amount of abrasion of the blade is detected from the results of measurements before and after the recessing. SOLUTION: For the recessing of a material to be processed such as a semiconductor wafer, a controller 10 rotates a blade 5 by a spindle 6 and transfers it by a set amount in the cutting direction by a precision table 8. After processing for a given time, the controller 10 returns the spindle 6 to a prescribed position by the precision table 8, again transfers a continuity sensor 2 toward the peripheral end of the blade 5 by the precision table 4, and operates the amount of transfer from a prescribed position of the continuity sensor 2 to the peripheral end of the blade 5. In this process, the amount of abrasion of the blade is obtained from the difference between the operation results before and after the processing. The amount of cutting can be kept constant by the correction for the abrasion of the blade 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a blade wear amount detection method and a semiconductor manufacturing apparatus, and more particularly to a blade dicing and slicing apparatus.

[0002]

2. Description of the Related Art A blade used for a dicing and slicing apparatus is a thin metal disk having a blade edge formed by electrodepositing abrasive grains on the peripheral edge thereof, and a workpiece is cut at a high speed. Therefore, as the cutting of the workpiece progresses, the abrasive grains gradually come off, that is, wear and deteriorate, and the cutting becomes worse, and in the dicing of the semiconductor wafer, the chopping of the cut surface of the semiconductor wafer becomes large and the wafer becomes large. May damage a part of the

Therefore, in a conventional dicing apparatus or the like, for example, in Japanese Unexamined Patent Publication No. 2-250769, a light projector capable of irradiating the blade tip with light, and a light receiver capable of measuring the amount of reflected light of this light, A control unit for stopping the blade based on the measurement result is shown.
According to this, the conventional blade wear detection focuses on the fact that the abrasive grains separate and the surface roughness of the blade edge decreases as the wear progresses, and the surface roughness of the blade edge changes due to the change in the reflected light amount of the light irradiated on the blade edge. I measure it.

Further, the wear is judged visually by the operator,
In some cases, a method of manually correcting the processed data may be used.

[0005]

However, in the conventional blade wear detection, since the wear state is judged by measuring the surface roughness, the blade replacement timing can be judged, but a quantitative judgment as the wear amount is made. Cannot be done. Therefore, there is a problem that the groove depth accuracy is greatly affected particularly in the grooving process.

In addition, when the wear amount is judged by the operator, a judgment error occurs by a person, and the correction is a manual work, which is a problem in automation.

Therefore, the present invention has been made in view of the above-mentioned conventional circumstances.
An object of the present invention is to provide a blade wear amount detection method and a semiconductor manufacturing apparatus capable of detecting the wear amount of a blade and automatically correcting the cut amount so that the cut amount due to the wear of the blade does not change. And

[0008]

In order to achieve the above object, the first invention is a method for detecting the amount of wear of a disk-shaped blade for performing a precise grooving process on a workpiece, and a predetermined method before the machining. The radial distance from the position to the peripheral edge of the blade is measured in advance, after grooving the workpiece, the radial distance from the predetermined position to the peripheral edge of the blade is measured again, before and after machining. The wear amount of the blade is detected from the measurement result of 1.

A second aspect of the present invention is a semiconductor manufacturing apparatus having a disk-shaped blade for performing precise grooving on a workpiece, wherein a spindle for rotating the blade at high speed is attached to the workpiece by a motor with a built-in scale. On the other hand, a precision table for a spindle that moves a set depth of cut from a predetermined position in the vertical direction, and a continuity sensor attached via an insulating material are mounted on a circumference of the blade from a predetermined position in the radial direction of the blade by a motor with a built-in scale. Precision table for the continuity sensor to be moved to the end, a sensing circuit for detecting the continuity of the blade and the continuity sensor, and the amount of movement from a predetermined position of the precision table for the continuity sensor at the time of continuity detection by the sensing circuit. Calculate the wear amount of the blade based on the change and set the notch in the precision table for the spindle Characterized by comprising a controller for correcting the.

In the present invention as described above, the radial distance from the predetermined position to the peripheral edge of the blade is measured in advance before processing, and after grooving the workpiece, the blade is moved from the predetermined position. The amount of wear of the blade can be detected by measuring the radial distance to the peripheral edge again and calculating the change in distance before and after machining.

Therefore, if the wear amount of the blade is quantitatively determined, the set movement amount of the spindle can be corrected so as to increase the cut amount by the wear amount, and the groove depth can be kept constant.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a basic block diagram of an embodiment of a semiconductor manufacturing apparatus suitable for the blade wear amount detecting method according to the present invention, as seen from above.

In the semiconductor manufacturing apparatus of this embodiment, as shown in FIG. 1, a spindle 6 for rotating a blade 5 at a high speed of, for example, 10000 to 70000 (rpm) is applied to a workpiece (not shown) by a motor 7 having a built-in scale. A precision table 8 for vertically moving a predetermined amount of cut from a predetermined position, and a continuity sensor 2 mounted via an insulating material 1 by a motor 3 with a built-in scale from the predetermined position in the radial direction of the blade 5 to the blade 5 from the predetermined position. Precision table 4 to move to the peripheral edge (blade edge),
A sensing circuit 9 that electrically detects the contact between the peripheral edge of the blade 5 and the continuity sensor 2, and a sensing circuit 9 and the motors 3 and 7 for detecting the wear amount and correcting the machining amount by the blade. And a controller 10 that operates.

The blade 5 and the spindle 6 are provided with conductivity so that when the continuity sensor 2 and the blade 5 are brought into contact with each other, the sensing circuit 9 and the blade 5 form a closed circuit.
Further, since the motors 3 and 7 with a built-in scale are used for precision machining of semiconductors, it is preferable to drive the precision tables 4 and 8 with a movement amount of at least a micron unit and self-detect the movement amount. For example, a rotary encoder. Examples include a stepping motor and a servo motor.

Next, the detection of the wear of the blade and the correction of the machining amount by the above apparatus will be described.

First, before processing, the controller 10 moves the continuity sensor 2 toward the peripheral edge of the blade 5 by the precision table 4. When the continuity sensor 2 comes into contact with the blade edge of the plate, the sensing circuit 9 operates and the controller 10 detects the contact. Based on this, the controller 10
The amount of rotation of the motor 3 from the origin is read and the amount of movement of the conduction sensor 2 from a predetermined position to the peripheral edge of the blade is calculated. After the calculation is completed, the controller 10 sets the precision table 4
To return the continuity sensor 2 to a predetermined position.

Next, in order to form a groove on a workpiece such as a semiconductor wafer, the controller 10 causes the spindle 6 to rotate the blade 5 and the precision table 8 to move the blade 5 in the cutting direction (perpendicular to the paper surface) by a set amount.

After machining for a certain period of time, the controller 10 returns the spindle 6 to a predetermined position by the precision table 8 and again directs the conduction sensor 2 toward the peripheral edge of the blade 5 by the precision table 4 as described above. Then, the amount of movement from the predetermined position of the continuity sensor 2 to the peripheral edge of the blade is calculated. At this time, the wear amount of the blade is obtained from the difference between the previous and present calculation results.

Then, based on the wear amount obtained by the controller 10, the controller 10 controls the precision table 8
By increasing (correcting) the amount of movement of the spindle 6 by the amount of wear of the blade 5, the amount of cut into the workpiece is kept constant.

If the wear amount is accumulated every time the wear amount of the blade is detected, the blade replacement time can be determined from the total wear amount, and the life of the blade can be managed.

[0022]

According to the present invention described above, the wear amount is calculated by the change in the radial distance from the predetermined position to the peripheral edge of the blade before and after machining to correct the cutting set amount by the spindle, so that the stability is stable. It is possible to perform grooving with a highly accurate depth of cut.

Further, the blade replacement time can be determined from the total amount of wear, and the life of the blade can be managed. As a result, it is not necessary to damage a work piece such as a semiconductor wafer during dicing.

[Brief description of drawings]

FIG. 1 is a basic configuration diagram showing an embodiment of a semiconductor manufacturing apparatus suitable for a blade wear amount detection method according to the present invention.

[Explanation of symbols]

 1 Insulation material 2 Continuity sensor 3, 7 Motor with built-in scale 4, 8 Precision table 5 Blade 6 Spindle 9 Sensing circuit 10 Controller

Claims (2)

[Claims] 1. A method for detecting the amount of wear of a disk-shaped blade for performing precise grooving on a workpiece, wherein the radial distance from a predetermined position to the peripheral edge of the blade is measured in advance before processing. However, after grooving the workpiece, the radial distance from the predetermined position to the peripheral edge of the blade is measured again, and the amount of wear of the blade is detected from the measurement results before and after processing. A method for detecting the amount of blade wear. 2. A semiconductor manufacturing apparatus having a disk-shaped blade for performing a precise grooving process on a workpiece, wherein a spindle for rotating the blade at a high speed is perpendicular to the workpiece by a motor with a built-in scale. A spindle precision table that moves a set depth of cut from a predetermined position, and a continuity sensor mounted via an insulating material are moved from a predetermined position in the radial direction of the blade to a peripheral edge of the blade by a motor with a built-in scale. A precision table for continuity sensor, a sensing circuit for detecting conduction between the blade and the continuity sensor, and a change amount of movement of the precision table for continuity sensor from a predetermined position at the time of continuity detection by the sensing circuit. Calculate the wear amount of the blade to correct the set depth of cut of the precision table for the spindle The semiconductor manufacturing apparatus characterized by comprising: a controller, a.