JPH01210314A - Dicing of semiconductor wafer - Google Patents

Abstract

PURPOSE:To ultrasonically clean adhesive adhered to a grindstone and consequently prevent the loading of the grindstone during cutting from occurring and make it possible to prolong the service life of the grindstone by a method wherein ultrasonic vibration is applied to the grindstone of a dicing saw after every end of water cutting in the process of the complete separation reaching an adherent sheet from the surface of a wafer. CONSTITUTION:In the process of the complete separation reaching an adherent sheet from the surface of a wafer, ultrasonic vibration is applied with an ultrasonic vibrator 2 to a grindstone, to which adhesive is adhered, for about one minute ranging from the end of wafer cutting to the start of next wafer cutting and simultaneously the ultrasonic cleaning is done by utilizing pure water 5 jetting from a cleaning nozzle 4. As a result, next wafer cutting can be done by a loading-free grindstone 3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for cutting semiconductor wafers into individual pellets.

[Conventional technology]

Conventionally, a method for cutting a semiconductor wafer involves, as shown in FIG. was attached to the sheet and cut into the sheet on the dicing saw table 11 from several μm to several tens of μm from the wafer surface as shown in FIG. 2(C), thereby completely cutting the wafer.

[Problem to be solved by the invention]

The conventional method of cutting a semiconductor wafer into individual pellets as described above is as shown in FIG.
As shown in 3, the adhesive adheres to the diamond particles,
Clogging occurred during cutting, causing rapid wear or damage to the grinding wheel, which affected the cost of the grinding wheel and the operating rate. Further, there were drawbacks such as generation of Si residue and increase in cutting width, which adversely affected quality. Note that the cutting is performed while spraying pure water 5 from the nozzle 4.

[Means to solve the problem]

The present invention was made to solve this problem, and its feature is that after complete cutting from the wafer surface to the adhesive sheet, while aligning for cutting the next wafer, The idea was to apply ultrasonic vibration to the grindstone and remove the adhesive that had adhered to it through ultrasonic cleaning.

〔Example〕

The present invention will be explained with reference to the drawings. Figure 1(a)
, (b) is a sectional view for explaining the first embodiment of the present invention. During complete cutting from the wafer surface to the adhesive sheet, after cutting the wafer as shown in Figure 1(a), the ultrasonic vibrator 2 bonds the wafer for about 1 minute before cutting the next wafer. By applying ultrasonic vibration to the grindstone 3 to which the agent has adhered, ultrasonic cleaning is simultaneously performed using pure water 5 from the cleaning nozzle 4. As a result, when cutting the next wafer as shown in FIG. 1(b), the cutting can be performed using the grindstone 3 without clogging.

FIG. 1(c) is a sectional view for explaining a second embodiment of the present invention. As in the first embodiment, after cutting a wafer, the ultrasonic cleaning tank 9 is installed below the standby position of the grinding wheel 3 for about one minute until the cutting of the next wafer is started. After ultrasonic cleaning step 3, raise the grindstone to the set height. In this way, the next wafer can be cut with a grindstone that is not clogged.

〔Effect of the invention〕

As explained above, in the process of complete cutting from the wafer surface to the adhesive sheet, the present invention applies ultrasonic vibration to the grinding wheel of the dicing saw after each wafer cutting process to remove the adhesive adhered to the grinding wheel. Sonic cleaning prevents clogging of the whetstone during cutting and increases the life of the whetstone. In addition, this reduces the time required to replace the grindstone, which has the effect of increasing the operating rate of the device. Furthermore, an increase in chipping, generation of Sl scraps, and defective scratches due to grindstone breakage, which are cutting defects due to clogging of the grindstone, are reduced, so an improvement in yield can be expected. Also, since it does not apply vibration during cutting, it goes without saying that it does not affect cutting accuracy.

[Brief explanation of the drawing]

FIGS. 1(a) and 1(b) are cross-sectional views showing the first embodiment of the present invention, FIG. 1(c) is a cross-sectional view showing the second embodiment, and FIG. 2(a)
-(c) are sectional views showing the conventional cutting method for semiconductor wafers, and (d) is a sectional view showing the state of the grindstone during conventional cutting. 1... Spindle rotating shaft, 2... Ultrasonic vibrator, 3... Grindstone with adhesive attached, 4...
...Washing nozzle, Death...Pure water, 6...
... Grindstone (after cleaning), 7... Semiconductor wafer,
8a...Sheet (adhesive), 8b...
Sheet (base material), 9... Ultrasonic cleaning tank, 10.
...Fixing frame, 11...Die cinder saw table. Agent Patent Attorney Otohara Uchihara Figure f (a) /? τ1fu (/:ninibu?-ru) and bji (b)? (Q)

Claims (1)

[Claims] A method in which the back side of a semiconductor wafer is bonded to a sheet with an adhesive and a dicing saw is used to completely cut the semiconductor wafer from the front surface to the sheet, including the step of applying ultrasonic vibration to a dicing grindstone. Characteristic semiconductor wafer cutting method.