JPS6335307A - Methd of cutting semiconductor wafer - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a cutting method for dividing a semiconductor wafer into chips.

Conventional technology The conventional technology will be explained using FIGS. 3 and 4.

In FIG. 3, as a cutting method for dividing the semiconductor wafer 1 into chips, there is a method of forming grooves of a constant depth in the scribe lane 3 between the chips 2 with a blade rotating at high speed. After cutting, the cross section of the semiconductor wafer at the center of the cut groove, for example along the line xx', is as shown in FIG. The thickness of the uncut portion (hatched) is 130 to 200 μm.

Problems to be Solved by the Invention The semiconductor wafer 1 from which the scribe lanes 3 have been cut is then broken into individual chips with the uncut portions. At this time, the uncut portion is often dispensed from the bottom of the cut groove toward the back surface of the semiconductor wafer 1 at an angle of 45 degrees with respect to the side surface of the cut groove or the back surface of the semiconductor wafer. If this leg surface 4 appears outside the side surface of the chip, the chip 2
The n-plane, for example, the AA' cross section is shown in FIG. 5(a), and the width of the chip surface is larger than the width of the chip surface by about twice the uncut thickness t of the semiconductor wafer. Therefore, as the uncut thickness of the semiconductor wafer increases, the width of the chip mounting plate 5 needs to have a larger margin than the original width of the chip 2 (width of the chip surface), and the chip mounting plate 5 becomes more sacred.

On the other hand, the male open surface 4 at the time of the semiconductor wafer minute v1 is shown in FIG.
), if it appears inside the side of the chip 2, it will be located at the periphery of the chip and the thickness of the chip will be reduced.
Chips are more likely to chip or crack during the subsequent assembly process. This defect becomes more likely to occur as the uncut thickness of the semiconductor layer increases.

For this reason, the smaller the uncut thickness of the semiconductor wafer is, the better; however, if it is too small, the semiconductor wafer after cutting will be more likely to break due to slight force or impact, and the semiconductor wafer will be transported from the semiconductor wafer cutting process to the process of dividing into chips. Alternatively, an accident may occur in which a semiconductor wafer breaks during cleaning work.

The present invention provides a method for cutting a semiconductor wafer, which can reduce the uncut thickness of the semiconductor wafer and prevent the semiconductor wafer from breaking after cutting.

Means for Solving the Problems In order to overcome the above-mentioned problems, the present invention covers cutting grooves between chips of a semiconductor wafer by forming shallow grooves at the peripheral edge of the semiconductor wafer and deep grooves inside the semiconductor wafer.

Effect: According to this cutting method, the semiconductor wafer from which the chips that become the product are made has a large uncut thickness at the periphery of the semiconductor die, and even the semiconductor wafer after cutting does not have enough strength to withstand transportation and cleaning operations. It is maintained.

EXAMPLE Hereinafter, an example of the semiconductor wafer cutting method of the present invention will be explained based on the drawings.

FIG. 1 is a sectional view at the center of a cut groove of a semiconductor wafer in which the present invention is implemented. The peripheral part of the semiconductor wafer 11,
For example, 10 to 20 IN from the outer periphery of the semiconductor tube 11.
#I shallow cutting groove (for example, uncut thickness t
200μm or more), and the cutting groove is deeper inside than that (for example, the uncut thickness t2 is 70 to 120μm).
rabbit) to form. A conventional dicing saw can be used as a device for carrying out the above-mentioned cutting, and the cutting can be easily carried out by changing the blade height control program. The semiconductor wafer cut in this way has a small uncut thickness in the area where the chip that will become the product will be tl.
It is possible to reduce the increase or decrease in the width of the back surface of the chip due to the occurrence of the surface area divided into individual chips. Therefore, Fig. 2 (a
), even when the male open surface 14 of the chip 12 appears outside the side surface of the chip, the width of the back surface of the chip does not conventionally increase as much as the width of the front surface of the chip. For this reason, chip 4
11! The width of the placement plate 15 does not require a large margin with respect to the original width of the chip (width of the surface). Also, Figure 2(b)
Even if the bulge surface 14 of the chip 12 appears inside from the side surface of the chip, the area where the thickness of the chip becomes smaller is limited to a very small area, and chipping or cracking of the chip may occur during the subsequent assembly process. Almost disappears.

On the other hand, the uncut thickness is large at the peripheral edge of the semiconductor wafer where almost no product chips can be removed.
Sufficient strength is maintained even after semiconductor wafers are cut, and accidents such as semiconductor wafers being broken during transportation or cleaning operations can be prevented.

Effects of the Invention According to Mitsuaki Ki, the cutting grooves between the chips of a semiconductor wafer are formed shallowly at the periphery of the semiconductor wafer and deep inside the semiconductor wafer, so the width of the chip surface is not as large as the width of the chip surface. Therefore, the depth mounting plate can be made smaller. In addition, chips and cracks are less likely to occur at the peripheral edge of the chip where the cutting grooves are shallow, and it is possible to prevent the semiconductor wafer from breaking during transportation and cleaning of the cut semiconductor wafer.

[Brief explanation of drawings]

Fig. 1 is a cross-sectional view at the center of the cut groove of a semiconductor wafer subjected to wood cutting, and Figs. 2 (a) and (b) are cross-sectional views of the semiconductor wafer subjected to the present invention after being divided into chips. FIG. 2(a) is a cross-sectional view of the chip 111!
3 is a plan view showing an example of a scribe plane for a semiconductor wafer, FIG. 4 is a sectional view at the center of the cutting groove of a semiconductor wafer cut by the conventional technique, and FIG. aHb) is a cross-sectional view of a chip after cutting a semiconductor wafer using the conventional technique into mid-chip parts.
FIG. 5(a) is a sectional view including the chip U placement plate. 11... Semiconductor wafer, 12... Chip, 14.
・Otoko Kaiji Agent Yahiro Moriki Figure 3 Figure S

Claims (1)

[Claims] 1. A semiconductor wafer cutting method in which cutting grooves between chips of a semiconductor wafer are formed shallowly at the periphery of the semiconductor wafer and deep inside.