JPH0710552U - Air spindle energization mechanism - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain an energization mechanism for an air spindle in which abrasion of the brush means can be minimized with a simple mechanism. An air spindle energizing mechanism for setting a reference position of a blade by energizing a chuck table and a blade, and brush means for contacting a required portion of the air spindle to form a current detection circuit, and a spindle of the brush means. At least pressure means for freely changing the pressing force on the shaft by adjusting the exhaust pressure of the air supplied to the air spindle.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a power supply mechanism for an air spindle.

[0002]

[Prior art]

 In a precision cutting device such as a dicing device, the reference position setting (setup) of a blade for dicing a wafer is performed by using an air spindle energizing mechanism, that is, by energizing the chuck table on which the wafer is placed and the blade, and thus the blade is set. Brush means (electrode for set-up) is brought into contact with the shaft of the mounted air spindle to form a current detection circuit.

[0003]

[Problems to be solved by the device]

 The above-mentioned conventional brush means is usually formed of carbon brush pieces, but since it is always in contact with the shaft of the air spindle, the carbon brush pieces are severely worn and must be replaced regularly and early. I don't get it. Some of them are equipped with a mechanism that completely separates the carbon brush piece except when setting it up to bring it into non-contact with the shaft, but the mechanism is complicated and expensive. The present invention has been made to solve such conventional problems, and an object thereof is to provide an energization mechanism for an air spindle which can minimize wear of the brush means with a simple mechanism. It is a thing.

[0004]

[Means for Solving the Problems]

 As a means for technically solving the above-mentioned problems, the present invention is an air spindle energizing mechanism that sets a reference position of a blade by energizing a chuck table and a blade. An air spindle energization mechanism including at least brush means that constitutes a detection circuit and pressure means that freely changes the pressing force of the brush means against the spindle shaft by adjusting the exhaust pressure of the air supplied to the air spindle. Is the gist.

[0005]

[Work]

 By adjusting the exhaust pressure of the air supplied to the air spindle with the pressure means, the internal pressure of the air spindle is made small at the time of setup to increase the contact pressure of the brush means, and the internal pressure of the air spindle is increased during normal use. Larger pressures reduce the contact pressure of the brush means, which minimizes the wear of the brush means.

[0006]

【Example】

 Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In FIG. 1, reference numeral 1 is a base of a dicing device, a chuck table 2 is formed on the upper surface of the base so as to be movable in the X-axis direction by an X-axis drive mechanism 3, and an air spindle unit 4 is supported by a Y-axis drive mechanism 5. It is formed so as to be movable in the X-axis direction via the base 6, and is also movable in the Z-axis direction via a mounting base 8 by a Z-axis drive mechanism 7 provided on the support base 6.

Reference numeral 9 is a conductive blade formed by nickel-plating diamond abrasive grains, which is detachably attached to the tip of the shaft 4a of the air spindle unit 4, and the blade 9 has a reference position in the Z-axis direction. Is set by energizing with the chuck table 2 holding the wafer 10 indicated by the chain double-dashed line, so that the air spindle energizing mechanism 11 is formed and the first current detecting means 12 provided in the circuit thereof is used. Detect current.

The air spindle energization mechanism 11 has a second current detection means 13, a switching switch 14, a power supply 15, and further includes a brush means 16 and a pressure means 17 shown in FIG.

The brush means 16 is provided in the back pressure chamber 20 of the spindle unit 4, and a pair of carbon brush pieces 16a are attached to a mounting hole 4b formed of an insulator 4f via a conductive spring 16b. The shaft 16a is urged by the spring 16b to contact the rear end of the shaft 4a. A conductive spring receiving piece 16c is fixed to the end of the mounting hole 4b. One of the spring receiving pieces 16c is a lead wire A to the power source 15 and the other is a lead wire to the second current detecting means 13. Each of them is connected to a wire B so that the shaft 4a can be energized when the reference position of the blade 9 is set. In addition, a small hole 4c is provided which communicates with the pair of mounting holes 4b at approximately the middle portion thereof and which is pulled out to the rear end of the air spindle unit 4.

The pressure means 17 includes a throttle valve 17 a provided in the exhaust pipe 18 of the back pressure chamber 20 and an electromagnetic valve 17 b provided in a thick branch pipe 18 a branched from the exhaust pipe 18. By adjusting the exhaust pressure of the chamber 20, the pressing force acting on the carbon brush piece 16a can be freely changed.

An air supply pipe 19 is connected to the air spindle unit 4 so that compressed air can be supplied to the internal air supply passage 4d, and a motor 4e for rotating the shaft 4a at a high speed is attached to a rear important part. Has been.

Next, the operation of the brush means 16 will be described with reference to FIGS. 1 and 2 in relation to the pressure means 17. First, at the time of setup, that is, when setting the reference position of the blade 9, the solenoid valve 17b is opened manually or by a command from the CPU. Then, a large amount of the supplied air is exhausted, and the internal pressure of the back pressure chamber 20 becomes small (approximately equal to atmospheric pressure). The carbon brush piece 16a strongly contacts the rear end of the shaft 4a of the air spindle 4 by the pressing force of the spring 16b.

In order to confirm whether or not this contact is surely made, the changeover switch 14 is changed over to the contact 14a side. Then, when both of the pair of carbon brush pieces 16 a are in contact with the shaft 4 a, the power source 15 energizes the shaft 4 a, and the current is detected by the second current detecting means 13.

After this confirmation, the changeover switch 14 is changed over to the contact 14 b side, and when the Z-axis drive mechanism 7 lowers the air spindle 4 little by little, it does not energize until the blade 9 comes into contact with the chuck table 2, but does not make contact. At that moment, a current flows through the circuit, and the current is detected by the first current detection means 12. Thereby, the reference position of the blade 9 can be set.

Next, the operation time, that is, the time when the wafer 9 is cut by the blade 9 will be described. When the solenoid valve 17b is closed after setting the reference position of the blade 9, the exhaust air of the air spindle 4 is slightly exhausted to the outside through the throttle valve 17a, so that the internal pressure of the back pressure chamber 20 becomes large and the pressing force of the spring 16b increases. Defeat and push back the carbon brush piece 16a. As a result, the contact pressure of the carbon brush piece 16a with respect to the shaft 4a is weakened, and part of the air in the mounting hole 4b is released to the outside from the small hole 4c due to the retreat of the carbon brush piece 16a.

At this time, the moving amount of the carbon brush piece 16a is determined by the internal pressure of the back pressure chamber 20, and the internal pressure is adjusted by the throttle valve 17a, that is, the carbon brush piece 16a is adjusted by the exhaust gas amount by the throttle valve 17a. It is possible to freely adjust the contact pressure of. The carbon brush piece 16a may be configured to be completely separated from the shaft 4a, but if it is brought into contact with the shaft 4a, the static electricity charged on the shaft 4a can be discharged (grounded through the lead wire B). So it is convenient.

In this way, the motor 4e is driven with the contact pressure of the carbon brush piece 16a against the shaft 4a weakened or without pressure, and the shaft 4a is rotated to cut (dicing) the wafer 10. It is possible to minimize the abrasion of the carbon brush piece 16a.

In the dicing process of the wafer 10, the Y-axis drive device 5 indexes the line (street) to be cut, and the X-axis drive mechanism 3 moves the chuck table 2 in the X-axis direction to rotate the blade 9 at a high speed. Carried out by.

[0019]

[Effect of device]

 As described above, according to the present invention, in the air spindle energizing mechanism such as a dicing device, by adjusting the exhaust pressure of the air supplied to the air spindle, the carbon brush piece is set on the shaft when the blade is set to the standard positioning. The carbon brush pieces are brought into contact with each other and pushed back during use to reduce the contact pressure on the shaft, so the wear of the carbon brush pieces can be minimized by a simple mechanism, and the brush means can be used for a long time and the number of replacements can be increased. It has excellent effects such as reduced workability and improved workability.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a schematic sectional view of the same.

[Explanation of symbols]

1 ... Base 2 ... Chuck table 3 ... X axis drive mechanism 4 ... Air spindle unit 4a ... Shaft 4b ... Mounting hole 4c ... Small hole 4d ... Air supply path
4e ... Motor 4f ... Insulator 5 ... Y-axis drive mechanism 6 ... Support stand 7 ... Z-axis drive mechanism 8 ... Mounting stand 9 ... Blade 10 ... Wafer 11 ... Air spindle energization mechanism 12 ... First current detection means 13 ... No. 2 Current detection means 14 ... Changeover switches 14a, 14b ... Contacts 15 ... Power supply 16 ... Brush means 16a ... Carbon brush piece
16b ... spring 16c ... spring receiving piece 17 ...
Pressure means 17a ... throttle valve 17b ... solenoid valve 1
8 ... Exhaust pipe 18a ... Branch pipe 19 ... Air supply pipe 2
0 ... Back pressure chamber

Claims (1)

[Scope of utility model registration request] 1. An air spindle energizing mechanism for setting a reference position of a blade by energizing a chuck table and a blade, the brush means constituting a current detection circuit by contacting a required portion of the air spindle, and the brush means. An air spindle energizing mechanism including at least a pressure means for freely changing the pressing force on the spindle shaft by adjusting the exhaust pressure of the air supplied to the air spindle.