JP2592488B2 - Dicing method for semiconductor wafer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Summary] The present invention relates to a dicing method for a semiconductor wafer, which cuts a semiconductor wafer and divides and separates a semiconductor chip. In a dicing method of a semiconductor wafer, in which a semiconductor wafer is fully cut using a blade, in order to prevent the semiconductor wafer from adhering to a surface, the semiconductor wafer is half-cut while leaving a thickness such that the semiconductor wafer is not broken by vibration. Thereafter, a colloid solution of an abrasive is supplied, and the remaining thickness of the half-cut semiconductor wafer is polished and cut by a hydroplaning phenomenon by the blade.

[Industrial applications]

The present invention relates to a method for dicing a semiconductor wafer, and more particularly to a method for dicing a semiconductor wafer by cutting a semiconductor wafer and dividing and separating semiconductor chips.

A semiconductor integrated circuit is formed as a plurality of chips on a semiconductor wafer, the wafer is diced and separated into chips, and the semiconductor chips are mounted on a package.

[Conventional technology]

Conventional dicing methods include a half-cut method and a full-cut method.

In the half-cut method, the wafer is diced with a blade from the element forming surface, leaving a thickness of several tens of μm to 200 μm, and thereafter, the wafer that has not yet been separated is pressed from the back surface with a roller to crack the undiced portion, The chip is divided and separated.

In the full-cut method, the wafer is completely diced from the element formation surface to the back surface with a blade to divide and separate chips.

[Problems to be solved by the invention]

In the conventional half-cut method, when cracking an undiced portion, the wafer is broken along its cleavage interface and not necessarily along the dicing direction. Therefore, the third
As shown in FIG. 1A, a notch 11 is formed on the back of each of the chips 10a to 10c.
a, 11b. This fold 11b is, as shown in FIG.
When the chip 10b is picked up, the chip 10b breaks and becomes a fragment 12, which adheres to the element forming surface of the adjacent chip 10c,
This may cause a malfunction of the semiconductor integrated circuit constituted by 0c.

Further, since the element forming surface 13 of each of the chips 10a to 10c is pressed during cracking, the element forming surface 13 may be damaged, and there is a problem that an extra cracking step is required, which is not suitable for automation. Was.

In the conventional full-cut method, when the dicing progresses and the uncut thickness becomes several tens of μm, the wafer is broken along the cleavage interface by the vibration generated by the dicing of the blade, similar to FIG. 3 (A). The folds 11a and 11b are generated. For this reason, there is a problem that the chips 12 adhere to the chip 10c when the chip 10b is picked up as in the case of FIG. 2B, which causes a malfunction of the semiconductor integrated circuit constituted by the chip 10c.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method of dicing a semiconductor wafer in which the chip element forming surface is less likely to be damaged and wafer fragments are not likely to adhere to the chip element forming surface. Aim.

[Means for solving the problem]

The semiconductor wafer dicing method according to the present invention is a semiconductor wafer dicing method in which a semiconductor wafer (30) is fully cut using a blade (22), wherein the semiconductor wafer (30) has a thickness that does not break due to vibration. Thereafter, a colloidal solution of an abrasive is supplied to polish and cut the remaining thickness of the semiconductor wafer (30), which has been half-cut by a hydrobraking phenomenon using a blade (22).

[Action]

In the present invention, the wafer (30) is polished and cut by the hydroplaning phenomenon of the colloid solution after the half-cut, so that the blade (22) does not directly hit the wafer (30) and the wafer (30) is prevented from being broken by vibration. it can.

For this reason, fragments of the wafer (30) are not generated during pickup and adhere to the element formation surface of the chip, and there is no risk of damaging this surface without inserting pressure on the element formation surface of the wafer.

〔Example〕

FIG. 1 is a view for explaining each step of the method of the present invention, and FIG. 2 is a plan view and a side view of a dicing apparatus applied to the method of the present invention.

First, a dicing apparatus will be described. In FIGS. 2 (A) and 2 (B), reference numeral 20 denotes a flange.
The blade 22 is fixed by screws 23, and the blade 22 is rotated in the direction of the arrow by the rotation of the rotating shaft 21 to perform dicing of the wafer 30.

The blade cover 24 covers above the flange 20 and the blade 22. Cooling water nozzles 25 and 26 for supplying cooling water and a colloid solution nozzle 27 for supplying a colloid solution are attached to the blade cover 24. Each of the nozzles 25 and 26 has a plurality of slits 28 for discharging cooling water,
22 are arranged so as to sandwich the vicinity of the position corresponding to the wafer 30. The nozzle 27 is disposed in front of the rotation at which the blade 22 hits the wafer 30. For example, a colloidal solution of silicon is released from the nozzle 27 and is hung on the tip of the blade 22.

To explain the method of the present invention, as shown in FIG.
An adhesive tape 33 is stretched over the full-cut frame 32, and the wafer 30 is adhesively fixed to the adhesive surface of the adhesive tape 33, and the wafer 30 and the adhesive tape 33 are fixed to the dicing table by vacuum suction.

First, a wafer 30 having a thickness of, for example, 490 μm is
μm by adjusting the height of the blade 22 so as to leave (by the thickness of the wafer is not broken), the half-cut by moving the blade 22 in the direction of arrow X _1. At this time, the cooling water is released from the nozzles 25 and 26, but the nozzle 27 is closed and the colloid solution is not released.

When the half-cut is completed, the height of the blade 22 is adjusted so that the thickness of the wafer 30 remains several μm, the nozzle 27 is opened together with the nozzles 25 and 26 to release the colloid solution, and the blade 33 is moved in the half-cut groove. direction of arrow X ₂ to fine speed movement.

At this time, the blade 22 does not directly contact the wafer 30, but the colloid solution is caught by the rotating blade 22 by the hydroplaning phenomenon and flows through the half-cut groove of the wafer 30 at high speed. For this reason, the wafer 30 is polished by the silicon colloid particles, and the wafer 30 is cut.

In this case, since the blade 22 does not contact the wafer 30,
The vibration of the wafer 30 is extremely small, so that the wafer 30 does not break along the cleavage interface, and it is possible to prevent fragments from being generated from the back surface of the chip when picking up the diced chip.

Further, unlike the conventional half-cut method, there is no need to press the element formation surface of the wafer 30, so that there is no risk of damaging the element formation surface.

Further, since the colloid solution is washed away by the cooling water, there is no problem at all.

Note that iron, ferrite, or the like may be used as the colloid particles in addition to silicon, and the above embodiment is not set.

〔The invention's effect〕

As described above, according to the semiconductor wafer dicing method of the present invention, there is no possibility of damaging the chip element forming surface, and it is possible to prevent the wafer fragments from being generated and adhering to the chip element forming surface, and thus the semiconductor wafer is manufactured. The cause of the malfunction of the semiconductor integrated circuit can be eliminated, which is extremely useful in practical use.

[Brief description of the drawings]

FIG. 1 is a view for explaining one embodiment of a wafer dicing method of the present invention, FIG. 2 is a view showing one embodiment of a dicing apparatus used in the method of the present invention, and FIG. 3 is a view for explaining a conventional method. FIG. In the figure, 22 is a blade, 25 and 26 are cooling water nozzles, 27 is a colloid solution nozzle, and 30 is a wafer.

Claims (1)

(57) [Claims] 1. A semiconductor wafer (3) using a blade (22).
0) In the method of dicing a semiconductor wafer to perform a full cut, the semiconductor wafer (30) is half-cut leaving a thickness that does not break due to vibration, and thereafter, a colloidal solution of an abrasive is supplied and the blade is cut. A dicing method for a semiconductor wafer, wherein the remaining thickness of the half-cut semiconductor wafer (30) is polished and cut by the hydroplaning phenomenon according to (22).