JPH04192348A - Method and apparatus for peeling tapes chip - Google Patents

Abstract

PURPOSE:To facilitate the work of picking up chips by expanding a wafer sheet to elongate its whole face and by vacuum-chucking it on a rugged chuck face. CONSTITUTION:A wafer sheet 5 is laid over an attraction table 1 by keeping chips 6 tape-cut in the dicing step, and an expand mechanism 2 is set to a frame 7 stuck on the peripheral edge. When the cylinder 21 of the expand mechanism 2 is actuated in this state to lower the frame 7, gaps of the chips 6 held by adhesion on the top face of the wafer sheet 5 enlarge. Next, a vacuum pump 3 is started to vacuum-draw the air in a closed space surrounded by the attraction table 1 and the wafer sheet 5. This deforms the wafer sheet 5 so as to adhere on a rugged attracting face 11. Therefore, chips 6 can be picked up simply from the wafer sheet 5 using an air pincette 8.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a tape chip peeling method 1 and a peeling apparatus for peeling diced semiconductor chips from a wafer sheet.

[Prior art] As a method for dicing semiconductor wafers, there is a tape cutting method in which the wafer is attached to a wafer sheet made of adhesive 1111 tape, and the wafer is fully cut in this state into small square chips. has been widely adopted. Further, the tape-cut chips are transferred from the dicing device to the next mounting process while being adhered to the wafer sheet, where the chips are individually picked up from the wafer sheet. The chips are picked up from the wafer sheet using a jig such as air tweezers equipped with a vacuum pad at the tip, either manually or by robot operation.

On the other hand, in the tape-cut state, the chips held on the wafer sheet are lined up across the fine grooves made by the guissing tool, and in this state, the chips are picked up from the wafer sheet using the above-mentioned pick-up jig. Then, adjacent chips may come into contact with each other and cause damage. Therefore, conventionally, prior to picking up chips, a wafer sheet holding chips is set in a device called an expander, and the wafer sheet is heated and stretched in the surface direction. A method in which the intervals are widened is generally adopted. By increasing the distance between the chips in this manner, the chip picking operation can be performed without interference with other chips.

(The evil that the invention attempts to solve) By the way, even if the method of expanding the wafer sheet prior to the big amplifier of the chip as described above is adopted, the following problems still remain.

That is, even if the wafer sheet is expanded, each chip is bonded to the wafer chip over its entire surface. Moreover, the adhesive force of the wafer sheet is strong enough to prevent the chips that have been cut into pieces from falling off the sheet. Therefore, in order to pick up a chip from a wafer sheet, it is necessary to apply a force greater than the adhesive force of the wafer sheet to the chip to peel off the adhesive. For this reason, especially when picking up chips manually, the workability is extremely poor and it is difficult to proceed with the work efficiently, which is a bottleneck in improving productivity.

The present invention has been made in consideration of the above points, and provides a tape chip peeling method and an apparatus therefor, in which the chip is almost completely peeled off from the wafer sheet prior to pickup, so that the chip pickup operation can be performed easily. The purpose is to

[Means to solve the problem]

In order to solve the above problems, in the peeling method of the present invention, a wafer sheet is placed on a suction table having an uneven suction surface while holding the wafer sheet, and while the wafer sheet is heated in this state. The wafer sheet is expanded to widen the distance between the chips, and the wafer sheet is then adsorbed onto the uneven suction surface of the suction table to remove the adhesion between the chips and the wafer sheet.

Here, in the above method, the wafer sheet can be expanded by pulling the wafer sheet covered with the tape from its periphery while keeping the suction table fixed, or by stretching the wafer sheet covered with the suction tape from its periphery. There is a method of fixing the wafer sheet and moving the suction table relatively to expand the wafer sheet.

The tape chip peeling method described above includes a suction table having an uneven suction surface, an expanding means for stretching the wafer sheet placed on the suction table in the entire direction, and a suction table that draws a vacuum on the wafer sheet. This can be carried out using a peeling device equipped with a suction means for adsorbing the wafer sheet onto the uneven suction surface and a heating means for heating the wafer sheet.

[Effect]

As described above, by expanding the wafer sheet and stretching the entire surface of the sheet, the chips held on the sheet are separated from each other, thereby increasing the distance between the chips.

Subsequently, when the wafer sheet is vacuum-adsorbed onto the uneven suction surface of the suction table, the chips are peeled off from the wafer sheet, leaving only the portion that contacts the convex portion of the suction table. In other words, the chip changes from the conventional surface bonded state to a line or point bonded state.

Therefore, chips can be easily picked up by pulling them off the wafer sheet with a small amount of force.

〔Example〕

The tape chip peeling method and device according to the present invention will be described below based on examples.

Embodiment 1: First, in FIG. 1, which shows the overall configuration of the peeling device, the peeling device has a suction table 1. Expanding mechanism 2. Vacuum pump 3. It consists of a hot plate 4 built into a suction table 1, and the like. In addition, 5 is a wafer sheet, 6 is a chip that is adhered and held on the upper surface of the wafer sheet 5 in a matrix pattern, and 7 is a ring-shaped frame (a dicing frame used in the dicing process) attached to the periphery of the wafer sheet 5. frame).

Here, the suction table 1 has an outer diameter smaller than the circular wafer sheet 5 to which the wafer 6 is attached, and its surface has an uneven suction surface 11 with protrusions lined up at small pitches like a sword pin. Further, vacuum passages 12 (see FIG. 2) which penetrate the table are perforated and distributed over the surface thereof. Then, the vacuum passage 12
is connected to the vacuum pump 3 on the back side of the suction table l. Furthermore, the suction table is equipped with a sliding ring 13 surrounding the outer periphery.

On the other hand, the expanding mechanism 2 includes a cylinder 21 and a frame presser 22 that is lowered by the cylinder 21, and is installed at several locations around the suction table 1 described above.

Next, a method for peeling off chips using the peeling apparatus having the above structure will be described. First, while holding the tape-cut chips 6 in the previous dicing process, the wafer sheet 5 is
is placed on the suction table 1 as shown in FIG. 1, and the expanding mechanism 2 is set on the frame 7 attached to the periphery of the suction table 1. Note that the suction table 1 is heated by a hot plate 4 to a temperature that softens the wafer sheet 5. In this state, the cylinder 21 of the expanding mechanism 2
When the frame 7 is lowered by operating the frame 7, the wafer sheet 5 is stretched in the radial direction around the entire circumference while sliding on the circumferential surface of the sliding ring 13. Therefore, as shown in FIG. 2, the distance d between the chips 6 adhesively held on the upper surface of the wafer sheet 5 increases.

Next, the vacuum pump 3 is started to evacuate the air in the closed space surrounded by the suction table 1 and the wafer sheet 5 placed on the top surface of the table 1. As a result, the wafer sheet 5 is deformed so as to come into close contact with the uneven suction surface 11 as shown in FIG. The adhesive is peeled off, and the chip 6 is now adhered to the sheet wafer 5 by spot adhesion instead of surface adhesion. Therefore, if the chip 6 is picked up in this state using a jig such as air tweezers 8, the chip 6 can be easily picked up from the wafer sheet 5 with a slight force.

Regarding the suction table 1, the uneven pitch shown in FIG.

An appropriate value is selected depending on the adhesive strength, etc.

Embodiment 2: FIG. 5 shows an applied example of Embodiment 1 described above. In Example 1, the periphery of the wafer sheet 5 was expanded by pulling it with the expanding mechanism 2 while the suction table 1 was kept fixed. In contrast, in this Example 2, the wafer sheet 5 placed on the suction table 1 was expanded as shown in the figure. The periphery is fixed via a frame 7, and the suction table 1 is moved upward by operating a cylinder 9. As a result, the wafer sheet 5 is stretched and expanded from the solid line to the position shown by the chain line. After the expansion, the wafer sheet 5 is vacuum-adsorbed onto the uneven suction surface of the suction table 1, and the gap between the chip 6 and the sheet 5 is peeled off, as in Example 1.

Note that this embodiment can also be implemented by incorporating the suction table 1 having an uneven suction surface into a conventionally used expanding ring.

In addition, in the case of Example 1.2, the chip pickup operation is carried out while the wafer sheet 5 is still adsorbed on the suction table 1, or after the wafer sheet 5 is given a pattern that follows the uneven suction surface. It is also possible to remove the chips 6 from the table 1 and pick them up from the wafer sheet 5 at another location.

〔Effect of the invention〕

As described above, the tape chip peeling method and device according to the present invention provide the following effects.

In the peeling method according to claims 1 and 2.3, prior to picking up the chips, the wafer sheet to which the chip cut by the tape cutting method is adhesively held is expanded to the entire wafer sheet, and the wafer sheet is adsorbed. Two operations are performed: adhering the chip to the uneven suction surface of the table and peeling off the adhesive between the chip and the wafer sheet, so when picking up the chip afterwards, just by applying a slight kick-up force, the chip can be attached to the wafer sheet. It can be easily picked up from the sheet, which improves the workability of picking up and greatly increases efficiency.

Furthermore, by employing the peeling apparatus of claim 4, the series of operations of expanding the wafer sheet and peeling off the chip and the sheet using the suction table can be performed continuously with the same apparatus.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of the entire peeling device according to an embodiment of the present invention, and FIGS.
Figure 4 is an enlarged view of the main parts of Figure 1 showing the state after arrival.
FIG. 5, which is a partially enlarged view of the suction table in the figure, is a schematic configuration diagram of an embodiment different from FIG. 1. l: Suction table, 11; Uneven suction surface, 12: Vacuum passage, 2: Expanding mechanism, 3: Vacuum pump, 4
: Hot plate, 5: Wafer Sea 21 Han 7 Baki Isoto [Isu P1 Tefurishi No. 1 Distance No. 2 Fig. 3 Kawari Fig. 5

Claims (1)

[Claims] 1) A tape chip peeling method in which diced chips are peeled off from a wafer sheet prior to chip pickup, in which the wafer sheet is placed on an uneven suction surface while holding the diced chips. The wafer sheet is placed on the provided suction table, and in this state, the wafer sheet is heated and expanded to widen the gap between the chips, and the wafer sheet is then adsorbed to the uneven suction surface of the suction table to bond the chips and the wafer sheet. A tape chip peeling method characterized by peeling off. 2) A tape chip peeling method according to claim 1, characterized in that the suction table is fixed and the wafer sheet placed over the tape is expanded by pulling it from its periphery. 3) A tape chip peeling method according to claim 1, characterized in that the periphery of the wafer sheet covered with the suction tape is fixed, and the suction table is relatively moved to expand the wafer sheet. 4) A tape chip peeling device that peels diced chips from a wafer sheet prior to chip pickup, which includes a suction table with an uneven suction surface and a wafer sheet placed on the suction table in the entire direction. What is claimed is: 1. A tape chip peeling device comprising an expanding means for stretching the wafer sheet, a suction means for vacuuming the wafer sheet and adhering it to the uneven suction surface of a suction table, and a heating means for heating the wafer sheet.