JP2532142B2 - Method for manufacturing semiconductor device - Google Patents

Description

The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which a wafer is cut into chips and the cut chips are picked up one by one, and cutting chips generated by cutting the wafer are effective. For the purpose of providing a method for manufacturing a semiconductor device that can be removed, a wafer is pasted on an adhesive tape, the wafer is cut into predetermined chips, and the chips are arranged at a pitch equal to or smaller than the size of the chips. The adhesive tape on which the cut wafer is placed is placed on the placing table on which the plurality of pointed projections are formed, and the surface of the cut wafer is covered with a protective tape. Vacuum suction is applied to the space formed between the lower surface of the tape and the gap between the pointed projections of the mounting table, the protective tape is removed, and the chips are picked up one by one. And a semiconductor device manufacturing method.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a semiconductor device, and more particularly to a method for manufacturing a semiconductor device in which a wafer is cut into chips and the cut chips are picked up one by one.

[Prior Art] In recent years, the demand for reliability has increased as semiconductor devices have become highly integrated. As a method of cutting the wafer into chips, a half-cut method in which the wafer is cut by half the thickness of the wafer and the cut wafer is cracked, and the wafer is attached to an adhesive tape, leaving only a small thickness of the attached wafer. There is a semi-full cut method in which the wafer is affixed to the adhesive tape, and a full cut method in which the wafer attached to the adhesive tape is completely cut.

In the half-cut method and the semi-full-cut method, the cut wafer is separated into chips by expanding the adhesive tape. However, since the expansion of the adhesive tape may not be performed uniformly, these methods may hinder the subsequent chip selection.

On the other hand, the full-cut method is promising as a wafer cutting method because it does not expand the adhesive tape.

[Problems to be Solved by the Invention] However, when the wafer is cut by the full-cut method, small cutting chips accumulate in the cutting groove, and when the chip is pushed up from the bottom when picking up the chip, the cutting chips in the cutting groove are generated. There is a problem that it pops out and is placed on the surface of the chip, and causes a short circuit between wires or a short circuit between pads.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method of manufacturing a semiconductor device capable of effectively removing cutting chips generated by cutting a wafer.

[Means for Solving the Problems] The purpose is to attach a wafer onto an adhesive tape, cut the wafer into a predetermined chip shape, and dispose a plurality of cusps arranged at a pitch equal to or smaller than the size of the chip. The adhesive tape on which the cut wafer is placed is placed on the placing table on which the head-shaped projections are formed, and the cut wafer surface is covered with a protective tape, and the lower surface and the front of the adhesive tape are covered. According to a method of manufacturing a semiconductor device, the space formed between the mounting table and the gap between the pointed projections is vacuumed, the protective tape is removed, and the chips are picked up one by one. .

[Operation] According to the present invention, the dust formed by adhering the cutting waste to the protective tape is removed by vacuum suction of the space formed between the adhesive tape and the gap between the pointed projections of the mounting table.

[Embodiment] A method for manufacturing a semiconductor device according to a first embodiment of the present invention will be described with reference to FIG. FIGS. 1 (a2) to (e2) are partially enlarged views of FIGS. 1 (a1) to (e1).

First, the wafer 10 to be cut is pasted on the adhesive tape 14 stretched by the frame 12 (Fig. 1 (a1), (a
2)). As the adhesive tape 14, polyethylene (PE) tape, polyvinyl chloride (PVC) tape, polyolefin (PO) tape, UV tape or the like can be used.

Next, by using a wafer cutting device (not shown), only the wafer 10 is fully cut so as not to cut the adhesive tape 14 to form a large number of chips 10a (FIGS. 1 (b1) and (b1)).
2)). The adhesive tape 14 may be slightly cut in order to completely cut the wafer 10. The cutting waste 16 resulting from the full cutting is accumulated in the cutting groove 18 as shown in FIG. 1 (b2).

Next, the adhesive tape 14 to which the wafer 10 is attached is placed on the placing table 20 which is a feature of this embodiment, and the surface of the wafer 10 is covered with the non-adhesive protective tape 22 (see FIG.
1), (c2)).

Details of the mounting table 20 will be described with reference to FIG. FIG. 1A is a plan view, and FIG. 1B is a cross-sectional view.

The outer wall 20b of the base 20a is for supporting the frame 12, and a large number of pointed projections 20c are formed inside the outer wall 20b. The pointed projection 20c has a pointed tip and has a shape like a sword mountain used for arranging flowers.
It is desirable that the pitch of the pointed projections 20c is slightly smaller than the size of the cut tip. For example, the mounting table 20 having the pointed protrusions 20c having a pitch of 1 mm is suitable for a wafer having a chip size of 1 to 2 mm, and the pointed protrusions 20c having a pitch of 3 mm are used.
The mounting table 20 having the above is suitable for a wafer having a chip size of 3 to 5 mm, and the mounting table 20 having the pointed projections 20c having a pitch of 5 mm is suitable for a wafer having a chip size of 6 mm or more.

When the adhesive tape 14 is placed on the mounting table 20, the space inside the outer wall 20b is sealed by the adhesive tape 14.

Next, when suctioned from the nozzle 20d, the space sealed by the pointed projections 20c of the base 20a and the adhesive tape 14 is vacuum-sucked and the force in the direction of contracting rapidly acts, as shown in FIG. 1 (d2). In addition, the portion of the adhesive tape 14 in contact with the closed space is pushed down vigorously. After all, this means that the adhesive tape 14
Is pushed up vigorously by the pointed projection 20c. At this time, when the wafer is cut by the full-cut method, when a chip is pushed up from below to pick up the chip, a phenomenon similar to the conventional phenomenon that cutting chips in the cutting groove jumps out, and The cutting waste 16 jumps up vigorously. The cutting dust 16 that jumps up vigorously sticks to the lower surface of the protective tape 22 or is adsorbed to the protective tape 22 by the force of static electricity (FIG. 1 (d1), (d2)). Since there is the protective tape 22, the cutting waste 16 that has jumped up is chipped.
It does not cause short circuit between wires or short circuit between pads on the surface of 10a. As the protective tape 22, for example, vinyl chloride tape is used.

At the same time, each chip 10a of the wafer 10 also has a pointed protrusion 2
It is pushed up by 0c, and the chip 10a is easily peeled off.

Next, the protective tape 22 is removed to remove the cutting waste 16 (Fig. 1 (e1), (e2)). Then, the chips are picked up one by one by a sorting device (not shown).

As described above, according to this embodiment, the cutting waste can be attached to the protective tape and removed. Therefore, the cutting waste does not occur on the surface of the chip to cause a short circuit between wires or a short circuit between pads.

Next, a method of manufacturing a semiconductor device according to the second embodiment of the present invention will be described with reference to FIG. Figure 2 (a2) ~ (f2)
FIG. 4 is a partially enlarged view of FIGS. The same parts as those in the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

The present embodiment is characterized in that a UV tape 24, which can reduce the adhesive force by irradiation with ultraviolet rays, is used as a tape for protecting the wafer 10 that has been fully cut.

The wafer 10 to be cut is attached onto the adhesive tape 14 (Figs. 3 (a1) and (a2)), and the wafer 10 is fully cut to form a large number of chips 10a (Figs. 3 (b1) and (b2)). ), After placing the adhesive tape 14 to which the wafer 10 is attached on the mounting table 20, the surface of the wafer 10 is covered with the UV tape 24 (FIGS. 3 (c1) and (c2)).

Then, vacuum suction of the closed space from the nozzle 20d,
Similar to the first embodiment, the adhesive tape 14 is pushed up by the pointed projections 20c, the cutting waste 16 in the cutting groove 18 flies vigorously, and collides with the lower surface of the UV tape 24. UV tape
Since 24 has an adhesive force, most of the cutting waste 16 is adsorbed to the UV tape 24 by the adhesive force (Figs. 3 (d1) and (d2)).

Next, the UV tape 24 is irradiated with ultraviolet rays to reduce the adhesive force (FIGS. 3 (e1) and (e2)). After reducing the adhesive strength, the UV tape 24 is removed from the wafer 10 (Fig. 3 (f
1), (f2)).

As described above, according to this embodiment, since the UV tape is used as the protective tape, the cutting chips can be efficiently captured.

The present invention is not limited to the above embodiment, and various modifications can be made.

For example, in the above embodiment, the case of cutting a semiconductor wafer has been described as an example, but the present invention can be applied to any wafer as long as a plate-shaped wafer is cut into chips other than the semiconductor wafer such as silicon or GaAs. Applicable.

[Advantages of the Invention] As described above, according to the present invention, it is possible to effectively remove the cutting chips generated by the cutting of the wafer.

[Brief description of drawings]

1 is a process sectional view of a method for manufacturing a semiconductor device according to a first embodiment of the present invention, FIG. 2 is a view showing a mounting table used in the method for manufacturing a semiconductor device, and FIG. FIG. 6 is a process sectional view of a method for manufacturing a semiconductor device according to a second embodiment. In the figure, 10 ... Wafer 10a ... Chip 12 ... Frame 14 ... Adhesive tape 16 ... Cutting waste 18 ... Cutting groove 20 ... Mounting table 20a ... Base 20b ... Outer wall 20c ... Pointed projection 20d ... Nozzle 22 ... Protective tape 24 … UV tape

Claims (1)

(57) [Claims] 1. A wafer on which an adhesive tape is attached, the wafer is cut into a predetermined chip shape, and a plurality of pointed projections arranged at a pitch equal to or smaller than the chip size are formed. On the mounting table, placing an adhesive tape on which the cut wafer is placed and covering the cut wafer surface with a protective tape, the lower surface of the adhesive tape and the pointed protrusions of the placing table described above. A method of manufacturing a semiconductor device, comprising vacuum suctioning a space formed between the gap and the protective tape, and picking up the chips one by one.