JPH02214611A - Dicing tape - Google Patents

Abstract

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

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a dicing tape for attaching or fixing a semiconductor wafer to a surface during dicing of the semiconductor wafer.

(Conventional technology) Conventionally, when cutting a semiconductor wafer pasted on a dicing tape with a dicing blade, in order to completely separate each chip from each other in the expansion process that follows the dicing tape, the depth of cut of the dicing blade is adjusted to match the dicing tape. The depth is set so that it can cut into the surface layer of the semiconductor wafer, thereby making it possible to completely cut into the semiconductor wafer.

[Problem to be solved by the invention]

In the conventional dicing described above, as the cutting of the semiconductor wafer progresses, the cutting depth of the dicing blade gradually becomes shallower due to wear of the dicing blade itself, and at a certain point the dicing blade no longer cuts the semiconductor wafer completely. , there was a problem that caused cutting defects.

However, the above problem can be overcome by resetting the cutting edge of the dicing blade to a predetermined depth of cut after cutting a certain number of semiconductor wafers, or by replacing the dicing blade itself. However, the wear of the dicing blade is not constant, and if the setting timing and replacement timing are determined by taking this into consideration for safety, it is assumed that waste will occur.

An object of the present invention is to provide a dicing tape that makes it possible to determine whether a dicing blade has cut into the surface layer of the dicing tape.

[Means to solve the problem]

In order to achieve the above object, the present invention provides a dicing tape for attaching or fixing a semiconductor wafer to a surface when cutting the semiconductor wafer with a dicing blade,
A non-transparent layer was formed on the surface layer to prevent light from passing through.

[Effect]

If a non-transparent layer is formed on the surface of the dicing tape in this way, if the dicing blade cuts into the non-transparent layer and cuts it off during dicing, the amount of light transmitted through the cut portion will increase. Therefore, if the reflective layer cannot be completely cut out due to insufficient cutting depth, the amount of light transmitted will decrease.

In this manner, the amount of light transmitted through the cut portion can be changed depending on whether the dicing blade cuts into the reflective layer or not.

〔Example〕

FIG. 1 shows a dicing tape 1 according to the present invention, and this dicing tape 1 has a non-transparent layer 2 formed on the surface layer 1a of the dicing tape 1 to prevent light transmission, for example, a base material layer 3. It is composed of an adhesive layer 4 laminated on top of which a pigment is mixed.

Next, a dicing device using this dicing tape 1 will be explained.

As shown in FIG. 2, the dicing device 5 includes a dicing blade 6 and a table 7, on which the dicing tape 1 is vacuum-adsorbed. The semiconductor wafer W is attached and fixed to the center of the upper surface of the dicing tape 1, and the semiconductor wafer W is cut by rotating the dicing tape 6 and moving the table 7.

To explain this in detail, the dicing blade 6 has a drive device (
(not shown), and is configured to be able to rotate and move up and down freely, and this drive device performs a descending motion to descend to a predetermined depth of cut at the start of cutting, and an ascending motion to return to the original position after cutting, while rotating at high speed. repeat. On the other hand, the table 7 is also rotated by a drive device (not shown) and rotates in the XY axis directions.
That is, it is configured to be movable in the cutting direction and the feeding direction, and immediately after the dicing blade 6 completes its descent by this drive device, the semiconductor wafer W is moved in the opposite direction to the cutting direction. When the cutting for one row is completed, the cutting for the next row is started, so the semiconductor wafer W is moved to the original position and then moved one pitch in the opposite direction to the feeding direction. By repeating this process, the semiconductor wafer W is cut into strips. Next, the semiconductor wafer W cut into strips is rotated 90 degrees, and the dicing blade 6 and table 7 are made to perform similar operations to cut the semiconductor wafer W into a third strip.
A large number of semiconductor chips Wa are formed by cutting into a movable lattice shape.

In this case, the depth of cut into the semiconductor wafer W by the dicing blade 6 is set to such a depth that it can cut to the surface layer la of the dicing tape 1 in order to completely separate each chip Wa in the expansion process following the dicing process. Set. Further, the cutting length in the cutting direction is such that the starting point and ending point of the dicing blade 6 are spaced slightly outward from the edge of the semiconductor wafer W so that the dicing blade 6 does not come into direct contact with the semiconductor wafer W when moving up and down. It is set to be located at .

Further, a light emitting element 8 and a light receiving element 9 are attached to the upper and lower sides of the table 7 by fixing members (not shown). Light is irradiated onto the cut groove 1b. The irradiated light passes through the cut groove 1b and is received by the light receiving element 9.

As a result, when the depth of the cut into the dicing tape 1 by the dicing blade 6 is sufficient, the non-transparent layer 2 in the cut groove 1b is further cut away by the cut of the dicing blade 6, and the light from the cut groove 1b portion is removed accordingly. However, as the dicing blade 6 wears out and the cut becomes shallow and the non-transparent layer 2 in the cut groove 1b is no longer cut by the dicing blade 6, the amount of light transmitted from this part increases. extremely reduced. Therefore, when the amount of transmitted light received by the light receiving element 9 suddenly increases from a steady state, the dicing blade 6 is no longer cutting into the non-transparent layer 2, and the cutting depth is insufficient. It will represent.

If this is explained schematically based on FIGS. 4 and 5, the dicing blade 6 is worn out, and as shown in FIGS.
), (C), and (D), if the cut groove 1b becomes shallower gradually, a cutting defect will occur in the semiconductor wafer W in the state of (D). On the other hand, the state of reflection of the light irradiated from the light emitting element 8 to the cut groove 1b is as shown in FIG. 5 (B).
In state (C), the amount of light reflected is small, but when state (C) is reached, the amount of light reflected suddenly increases. Therefore, if the dicing is stopped when the amount of reflection increases rapidly and the cutting depth is reset or the dicing blade 6 is replaced, defective cutting of the semiconductor wafer W can be prevented.

If this is specifically related to the control of the dicing device 5, control as shown in FIG. Light is irradiated onto the cut groove 1b, and the reflected light is received by the light receiving element 9. The amount of light received by the light-receiving element 9 is detected by the amount of received light detector 11, and the amount of received light detector 11 detects when the amount of received light suddenly increases from a steady state.
send a signal to controller 12; The controller 12 prioritizes this signal and controls the blade lifting drive section 13 to raise the dicing blade 6 and then stop it.

In this example, the adhesive layer 4 itself was made of a non-transparent material, but the non-transparent layer 2 is composed of the base material layer 3 of the dicing tape 1 and the adhesive layer 4, as shown in FIG. 7(A). Alternatively, as shown in FIG. 7(B), it may be provided on the upper surface of the adhesive layer 4 except for the part to which the semiconductor wafer W is attached. On the other hand, the detection of reflected light is performed on a single semiconductor wafer W.
The cutting is performed for one or more arbitrary cut grooves 1b, or for each cut groove 1b as the case may be.

[Effect of the Invention J As described above, according to the present invention, by providing a non-transparent layer on the surface layer, the amount of light reflection can be changed depending on the cutting depth of the dicing blade, and the dicing blade can perform dicing. This has the effect of being able to determine whether or not the tape has been appropriately cut.

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[Brief explanation of the drawing]

Fig. 1 is a cut side view of a dicing tape according to the present invention, Fig. 2 is a perspective view of a dicing device, Fig. 3 is a plan view of a semiconductor wafer in a cut state, and Fig. 4 shows the cutting state of the dicing blade. FIG. 5 is a cut side view showing the state of light transmission, FIG. 6 is a control flow diagram of the dicing device, and FIG. 7 is a cut side view of a modification of the dicing tape. 1... Dicing tape, 1a... Surface layer part, 1b.
... Cut groove, 2... Non-transparent layer, 6... Dicing blade, W... Semiconductor wafer. 7゛Ishisig Alternative 2nd WJ Diagram Size #20- Diagram

Claims (1)

[Claims] A dicing tape for attaching and fixing a semiconductor wafer to a surface when cutting the semiconductor wafer with a dicing blade, the dicing tape having a non-transparent layer formed on the surface layer to prevent light transmission.