Grinding device

Abstract

The invention provides a grinding device. The grinding device (1) comprises an ultrasonic cleaning water provision unit (9) for spraying cleaning water spread with ultrasonic waves to a grinding face (740a) of a grinding tool (740) of a grinding unit (7); a current value detection part (14) for detecting current values of a main shaft motor (72); and a switching on / switching off unit (16) for switching on / off of oscillation of the ultrasonic waves according to the current values detected by the current value detection part (14). The switching on / switching off unit (16) sets an upper limit value and a lower limit value for a current value, which is changeable during grinding by the grinding unit (7) and detected by the current value detection part (14), of the main shaft motor (72). Between the upper limit value and the lower limit value of the current value, by use of switching on / switching off unit (16), the high frequency electric power of a high frequency power supply (91) of the ultrasonic cleaning water provision unit (9) is switched and grinding is performed.

Description

technical field [0001] The present invention relates to a grinding device capable of grinding a grinding wheel by contacting a wafer. Background technique [0002] As semiconductor wafers, sapphire, SiC, lithium tantalate (LiTaO 3 ), glass, etc., after being ground to a predetermined thickness by a grinding device, it is divided into individual devices by a cutting device and the like, and is used in various electronic devices and the like. As a grinding apparatus used for this grinding, it is possible to grind a wafer by bringing the grinding surface of a rotating grinding wheel into contact with a wafer as a workpiece. Here, when this grinding is performed, clogging or passivation due to grinding debris or the like occurs on the grinding surface of the grinding wheel, and the grinding force of the grinding wheel decreases. In addition, when the workpiece is a so-called difficult-to-grind material, clogging or passivation of the grinding wheel occurs particularly frequent...

AI Technical Summary

Problems solved by technology

[0005] However, when a wafer is ground using the grinding apparatus described in Japanese Patent Application No. 2014-084198, the following phenomenon has been confirmed: when only ultrasonic waves are continuously oscillated from the ultrasonic oscillator during grinding and When the ultrasonic wave is continuously transmitted in the cleaning water, the grinding force of the grinding tool will be reduced

Therefore, in the case of grinding a wafer using a grinding device that sprays cleaning water propagating ultrasonic waves onto the grinding surface of the grinding wheel to clean the grinding surface, there is a problem of maintaining a high grinding rate. cutting force while efficiently grinding wafers in a continuous manner

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