JPS6142931A - Dividing method for semiconductor wafer - Google Patents

Abstract

PURPOSE:To remove defective chips easily by dividing a wafer into each chip and making the defective chips adhere to a composite resin sheet on the upper side for removal thereof after making an ink mark having a strong adhesion adhere onto a defective chip member and applying the composite resin sheet to both faces of a wafer for vacuum seal. CONSTITUTION:After sol-like silicon resin is made to adhere to the surface of a chip member 1a which has been defective, it is dried to strengthen adhesion thereof to a vinyl chloride sheet. Next, cut-grooves 3 for division which are partitioned into each chip member 1a and provided on the surface of a wafer 1 like a square on a go board. A No.1 vinyl sheet 4 and a No.2 vinyl sheet 5 are overlapped on the wafer 1 in this state from the back and the surface respectively to exhaust air between the vinyl sheets 4 and 5. Thus, the space therebetween is brought into a vacuum seal state. Next, the wafer 1 is pushed up from the back of the vinyl sheet 4 by a roller to divide thereof into each chip 6 clong cut-grooves chips 6 are removed by an ink mark 3 with the defective chips 6 made to adhere to the vinyl sheet 5.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] This invention divides one surface into a number of semiconductor chips along cut grooves cut into a grid pattern. This invention relates to a method for dividing semiconductor wafers.

[Conventional technology]

A first step is used as a method of dividing a semiconductor wafer (hereinafter referred to as "wafer") on which a required active region is formed to obtain a large number of integrated semiconductor chips (hereinafter referred to as "chips"). (a) Cut grooves (scribe lines) for dividing into required chips are cut in a grid pattern on the surface of a wafer formed into a thin plate shape. (b) By applying a push-up blade to the wafer in this state from the back side, a crack is created along the cutting groove and the chip is divided into individual chips.

(c) Select the required chips.

Among these, in order to easily obtain individual chips in steps (b) and (c) with a high yield, conventional methods are used.

It was done by the following method.

(A) A first vinyl chloride sheet is applied to the back side of the wafer, which has cut grooves in a grid pattern on the front side.

A second vinyl chloride sheet is applied to the surface, and the wafer is vacuum sealed (vacuum packed) between both sheets.

(B) Using a roller corresponding to the required chip size, a push-up blade is applied to the wafer from below to divide it into individual chips.

(0) Second vinyl chloride sheet on the front side (hereinafter “
(referred to as "vinyl sheet"). At this time, each chip remains attached to the first vinyl chloride sheet (hereinafter referred to as "vinyl sheet").(D) The first vinyl sheet in this state is stretched in all directions, and Keep it.

In this way, by using the sheet stretching method, each chip can be arranged in an orderly manner with the required spacing.

You can easily select the desired chip: 1″!!
Ta. Chips can be sucked and removed using a suction tool.
This makes it easier to assemble semiconductor devices.

In the conventional method described above, individual chips are aligned at appropriate intervals, but defective chips are mixed with good chips and are aligned. It was troublesome to have to differentiate by method.

[Summary of the invention]

In this invention, a highly adhesive ink mark is attached on the defective chip part of the wafer 1, grooves are cut in a checkerboard pattern on the surface of the wafer 1, and first and second marks are placed on the back and front surfaces of the wafer 1. After overlapping and covering the second synthetic resin sheet and vacuum sealing, the Ueno® is divided into chips along the cut grooves, and by peeling off the second synthetic resin sheet, the chips are adhered with ink marks. Both defective chips are removed so that only good chips remain on the first synthetic resin sheet.

It is an object of the present invention to provide a semiconductor wafer dividing method in which defective chips are easily removed and assembly workability in the VK process is greatly improved.

[Embodiments of the invention]

Hereinafter, a method for dividing a wafer according to an embodiment of the present invention will be explained with reference to FIG.

FIG. 1 is a plan view of a wafer, and the wafer (1) is a substrate made of, for example, gallium arsenide, on which a large number of chip portions (1a) of field effect transistors are formed.

Characteristic tests were sequentially performed on all chip parts (1a).

For defective chips a(la)K, an ink mark (3) indicating a defective product is attached by an ink adhering device (not shown). What is the size of this ink mark (2)?

Make it smaller than the size of the chip part (1a). The ink material for this ink mark (2) is 1, for example, Tone Botting Resin SH-1840 (silicone resin,
(trade name, manufactured by Toshi Silicone Co., Ltd.) and a curing agent are sufficiently mixed to obtain an appropriate viscosity. The silicone resin after this mixing is in a sol state. In addition.

This silicone resin is transparent, so if there is any problem,
If necessary, coloring ink may be mixed in.As described above, after adhering the sol-like silicone resin to the surface of the chip part (1a) that failed in the characteristic test, it was placed in a clean air-conditioned atmosphere. Dry (e.g. 90°C for 10 minutes) in
let Then, the dot-shaped ink mark (2) becomes sol-like and has a large adhesive force, and has a strong adhesion force to the vinyl chloride sheet.

Next, each chip part (1a) is placed on the surface of the wafer (1).
Divide into sections and cut grooves (3) for division into a grid pattern.

To process this cut groove (3), a device such as a diamond scriber or a guising gun is used.

As shown in Figure 2, the first vinyl sheet (4) is superimposed on the Ueno straight 1) in this state, and the second vinyl sheet (5) is superimposed on the front surface. , (5) uses a material with high extensibility.

As shown in the cross-sectional view in Figure 3, the wafer (1) is placed on the vinyl sheet (4) with its back side in contact with the wafer (1).
1) Overlay the vinyl sheet (5) on top of the surface and vinyl sheet (4). In this way, the air between the cylinder seats (4) and (5) is evacuated by a vacuum pump (not shown in the drawings), and a vacuum seal is created.

At this time, the vinyl sheet (5) must be wide enough to cover the entire wafer (1) and overlap the vinyl sheet (4) on its periphery, and its material must be compatible with the attached and processed ink marks (3). Use a material with appropriate adhesion.

Next, from the back side of the vinyl sheet (4), insert the chip part (
Using a roller (not shown) according to the size of 1a),
The wafer (1) is pushed up and divided into chips (6) along the cut grooves (2) K as shown in FIG.

Next, as shown in Figure 5, the end of the vinyl sheet (5) is pinched with tweezers (7) and pulled off.

The defective chip (6) is removed with the ink mark (3) still attached to the vinyl sheet (5).

In this way, as shown in Figure 6, the vinyl sheet (4)
Only the good chips (6) remain aligned on the top.

Thereafter, when the vinyl sheet (4) is stretched in all directions by the stretching means, the remaining non-defective chips (6) are spaced apart from each other, as shown in FIG. By holding the vinyl sheet (4) in an expanded state in this way, the desired chips (6) can be easily selected. In this case, only non-defective chips (6) are aligned, and work efficiency is greatly improved in assembly in the subsequent process.

The material for the ink mark (3) is vinyl sheet (
A material with stronger adhesion to the wafer (1) and the vinyl sheet (5) than the adhesive (4) was selected and tested. Use a material that does not adversely affect the chip (6) and vinyl sheet (5).

In the above embodiment, the ink mark (3) is made of silicone resin, but is not limited to this, and may be made of other materials as long as it satisfies the above conditions.

Further, in the above embodiment, the wafer (1) is made of gallium arsenide, but it may be a semiconductor substrate made of other materials.

Furthermore, as a sheet for holding the wafer (1).

In the above example, (vinyl chloride sea) (4), (
5) was used, but it has excellent extensibility and wafers can be easily attached to it.

Other types of synthetic resin sheets may be used as long as they are easy to peel off.

[Effects of the Invention] As described above, according to the method of the present invention, a highly adhesive ink mark is attached on the defective chip portion of a wafer, and a first synthetic resin sheet is applied to the back surface of the wafer. 1 surface is covered with a second synthetic resin sheet, and after vacuum sealing, the wafer is divided into each chip along the cut grooves, and the second
Peel off the synthetic resin sheet and remove the defective chip from this second
Since the ink mark is removed with the ink mark still attached to the first synthetic resin sheet, defective chips are easily removed and only good chips are left on the first synthetic resin sheet for assembly in the subsequent process. This greatly improves the efficiency of gleaning and facilitates automation.

[Brief explanation of drawings]

Figures 1 to 7 show a method of dividing a semiconductor wafer according to an embodiment of the present invention in steps @, and Figure 1 is a plan view of the wafer with ink marks attached to defective chip parts and cut grooves made. , Figure 2 is a perspective view of the wafer in Figure 1 being covered with a vinyl sheet from the front to the back, and Figure 3 is a perspective view of the wafer in Figure 2 covered with a vinyl sheet and vacuum sealed. The fourth factor is a cross-sectional view of the wafer in Figure 3 divided into chips, and Figure 5 is the state in which the vinyl sheet on the front side of Figure 4 is removed and all defective chips are removed. Figure 6 is a cross-sectional view of the state shown in Figure 5 with only good chips remaining on the back side vinyl sheet, and Figure 7 is a cross-sectional view of the state shown in Figure 5 with only good chips remaining on the back side vinyl sheet. FIG. l...Semiconductor wafer, la...Chip part, 2...
・Ink mark, 3... Cut groove, 4... First vinyl chloride sheet (synthetic resin sheet), 5... Second vinyl chloride sheet (synthetic resin sheet), 6... Semiconductor chip The same line numbers in Figure 1 indicate the same or equivalent parts.

Claims (3)

[Claims] (1) A process of inspecting the characteristics of all the chip parts in multiple arrays formed on the semiconductor wafer, and attaching an ink mark with strong adhesion on the defective chip part, and marking each of the chip parts on the surface of the semiconductor wafer. a step of making cut grooves in a checkerboard pattern for dividing and dividing the semiconductor wafer, and a step of vacuum-sealing the semiconductor wafer by covering it from the back side and front side with highly extensible first and second synthetic resin sheets; Adding a push-up blade to the semiconductor wafer in this state from the back side and dividing it into a large number of semiconductor chips along the cut grooves,
removing the defective semiconductor chips attached to the second synthetic resin sheet by the ink marks by peeling off the second synthetic resin sheet on the surface; A method for dividing a semiconductor wafer comprising the steps of stretching the semiconductor wafer in all directions and widening the mutual spacing between the remaining good semiconductor chips. (2) The method for dividing a semiconductor wafer according to claim 1, wherein the ink mark uses silicone resin ink. (3) The method for dividing a semiconductor wafer according to claim 1 or 2, wherein the synthetic resin sheet is a vinyl chloride sheet.