JPH02214610A - Dicing tape - Google Patents

Abstract

PURPOSE:To discriminate whether notching has reached to the surface layer section of a dicing tape of a dicing blade or not by forming a reflecting layer reflecting light or an antireflection layer preventing the reflection of light to the surface layer section of the dicing tape, on a surface of which a semiconductor wafer is stuck and fixed. CONSTITUTION:In a dicing tape 1, on a surface of which a semiconductor wafer W is stuck and fixed when the semiconductor wafer is cut by a dicing blade 6, the reflecting layer 4 or antireflection layer 14 of light is shaped between a base material layer 2 and an adhesive layer 3 as a surface layer section 1a. When the reflecting layer 4 is formed to the surface layer section at that time, the quantity of the reflection of light in a notch section 1b is reduced when the dicing blade 6 is notched up to the reflecting layer 4 and the layer 4 is cut off, and the quantity of the reflection of light is increased when notch depth is insufficient and the reflecting layer is not cut off. When the antireflection layer 14 is shaped similarly to the surface layer section, the quantity of the reflection of light in the notch section is augmented when the dicing blade 6 is notched sufficiently up to the antireflection layer 14 and the layer 14 is cut off, and the quantity of the reflection of light is diminished when notch depth is insufficient and the antireflection layer is not cut off.

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 attached to 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 process, the cutting depth of the dicing blade was set to the surface layer of the dicing tape. The depth is set such that the cutting depth is deep enough to allow complete cutting into the semiconductor wafer.

[Problem to be solved by the invention]

In the above-mentioned conventional dicing, as the cutting into semiconductor wafers progresses, the dicing blade itself wears out, etc.
The depth of cut of the dicing blade gradually becomes shallower, and after a certain point, the dicing blade no longer cuts the semiconductor wafer completely, resulting in poor cutting.

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 the surface of a source for cutting the semiconductor wafer with a dicing blade, comprising:
A reflective layer that reflects light was formed on the surface layer, or an antireflection layer that prevented reflection of light was formed on the surface layer.

[Effect]

By forming a reflective layer on the surface layer of the dicing tape in this way, if the dicing blade cuts into the reflective layer and cuts it off during dicing, the amount of light reflected from the cut portion will be reduced. If the depth of cut is insufficient and the reflective layer cannot be completely cut out, the amount of light reflected will increase. In this way, the amount of light reflected at the cut portion can be changed depending on whether the dicing blade cuts into the reflective layer or not.

Similarly, if an anti-reflection layer is formed on the surface of the dicing tape, if the dicing blade cuts deep enough into the anti-reflection layer and cuts it off, the amount of light reflected at the cut portion will increase. If the cut depth is insufficient and the antireflection layer is not completely cut out, the amount of light reflected will be reduced.

〔Example〕

FIG. 1 shows a dicing tape 1 according to the present invention,
This dicing tape 1 has a reflective layer 4 that reflects light between a base layer 2 and an adhesive layer 3, which are the surface layer 1a of the dicing tape 1. For example, the base layer 2 is made of vinyl chloride or the like. It is a polymer film, and the reflective layer 4 is composed of a thin metal film deposited or sputtered on the polymer film.

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 dicing tape is attached to the semiconductor wafer W.
Cutting is performed by rotating the pulley 6 and moving the table 7.

To explain this in detail, the dicing blade 6 is configured to be rotatable and movable up and down by a drive device (not shown). The rising motion of returning to the original position is repeated while rotating at high speed. On the other hand, the table 7 is also configured to be rotatable and movable in the XY axis directions, that is, in the cutting direction and the feeding direction, by a drive device (not shown), and immediately after the dicing blade 6 completes its descent by this drive device, The semiconductor wafer W is moved in a direction opposite to the cutting direction. When cutting for one row is completed, 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 operated in the same manner to cut the semiconductor wafer W into a grid pattern as shown in FIG. 3, resulting in a large number of semiconductor chips. Form Wa.

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 into the surface layer 1a of the dicing tape 1 in order to completely separate each chip Wa in the expansion step following the dicing step. Set. The length of the cut in the cutting direction is determined by how far the starting point and end point of the dicing blade 6 are away 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 outward.

A light emitting element 8 and a light receiving element 9 are attached to the table 7 by fixing members (not shown), and the light emitting element 8 allows the portion of the semiconductor wafer/%W left on the dicing tape 1 to be removed. Light is irradiated onto the cut groove 1b. The irradiated light is reflected by the cut groove 1b and is received by the light receiving element 9.

As a result, when the depth of cut into the dicing tape 1 by the dicing blade 6 is sufficient, the reflective layer 4 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 reduced accordingly. The amount of light reflected decreases, but eventually, as the dicing blade 6 wears out and its depth of cut becomes shallow, and the reflective layer 4 in the cut groove 1b is no longer cut by the dicing blade 6, the amount of light reflected from this portion increases. do. Therefore, the light receiving element 8
If the amount of reflected light received by the dicing blade suddenly increases from a steady state, this indicates that the dicing blade 6 is no longer cutting into the reflective layer 4, and the cutting depth is insufficient. becomes.

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), as the depth of cut 1b gradually becomes shallower, a cutting defect will occur in the semiconductor wafer W in the state of (D). The state of reflection of the irradiated light is as shown in Figure 5 (B
), the amount of light reflected is small (steady state a), but (C
), the amount of reflection 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. 6 can be considered.

According to this, light is irradiated from the light emitting element 8 to the cut groove 1b of the dicing tape 1 in response to a signal from the light emitting element driving circuit 10, 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 next received light amount detector 1.
The received light amount detector 11 sends a signal to the controller 12 when the received light amount suddenly increases from a steady state. The controller 12 prioritizes this signal and controls the blade lifting drive section 13 to raise the dicing blade 6 and then stop it.

Next, another embodiment of the present invention will be described with reference to FIGS. 7 and 8.

The dicing tape 1 of this embodiment has an anti-reflection layer 14 for preventing light reflection between the base layer 2, which is the surface layer 1a of the dicing tape 1, and the adhesive layer 3. Layer 2 is a polymer film such as vinyl chloride, and antireflection layer 14 is a thin film of magnesium fluoride deposited on the polymer film. As a result, when the depth of the cut into the dicing tape 1 by the dicing blade 6 is sufficient, the antireflection layer 14 within the full cut 1b is cut by the dicing blade 6, and the amount of light reflected from this part increases. do. When the dicing blade 6 wears and the depth of cut becomes shallow and the antireflection film 14 in the cut groove is no longer cut by the dicing blade 2, the amount of light reflected from this portion decreases. Therefore, when the amount of reflected light suddenly decreases from a steady state, the dicing blade 6 is no longer cutting into the anti-reflection film 14.
This indicates that the depth of cut is insufficient.

In this example, the reflective layer 4 and the antireflection layer 14 are provided between the base layer 2 and the adhesive layer 3 of the dicing tape 1, but as shown in FIG. It may be provided on the upper surface of the adhesive layer 3 except for the part to which the wafer W is attached, or the adhesive layer 3 itself may be made of a reflective or anti-reflective material as shown in FIG. 9(B). good. Also,
Detection of reflected light is performed for one or more arbitrary cut grooves 1b on one semiconductor wafer W, or for each cut groove 1b as the case may be.

〔Effect of the invention〕

As described above, according to the present invention, by forming a reflective layer or an antireflection layer on the surface layer, the amount of light reflected can be changed depending on the cutting depth of the dicing blade.
This has the effect of making it possible to determine whether or not the dicing blade is cutting into the dicing tape appropriately.

Fig. 1 is a cut side view of the dicing tape according to the present invention, Fig. 12 is a perspective view of the dicing device, Fig. 3 is a plan view of the wafer in the cutting state, and Fig. 4 shows the cutting state of the dicing blade. 5 is a cut side view showing the reflection state of the cut groove portion, FIG. 6 is a control flow diagram, FIG. 7 is a cut side view of the dicing tape of the second embodiment, and FIG. 8 is a cut side view showing the reflection state of the cut groove portion. FIG. 9 is a cut side view showing the reflection state of the cut groove portion, and FIG. 9 is a cut side view of a modified example of the dicing tape.

1... Dicing tape, 1a... Surface layer part, 1b.
... Cut groove, 4... Reflective layer, 6... Dicing blade, 14... Antireflection layer, W... Semiconductor wafer.

Patent applicant: Sumitomo Electric Industries, Ltd. Representative patent attorney Yoshiki Hase f7J1!5T
8ΔMi F' attack Figure 4 S 1 set 11 g 5 Figure 2' Gr surface Figure 1 Dicing equipment No. 25! J w1 quiet flow diagram 6

Claims (1)

[Claims] 1. A dicing tape for attaching and fixing a semiconductor wafer to the surface when cutting the semiconductor wafer with a dicing blade, characterized in that a reflective layer that reflects light is formed on the surface layer. dicing tape. 2. A dicing tape for attaching and fixing a semiconductor wafer to the surface when cutting the semiconductor wafer with a dicing blade, the dicing tape having an anti-reflection layer formed on the surface layer to prevent reflection of light. .