JPH05299504A - Dicing method - Google Patents

Abstract

PURPOSE:To decrease the irregularity in the remaining margin of each adhesive sheet as much as possible, and to sufficiently ensure the strength of the adhesive sheets. CONSTITUTION:When a semiconductor wafer 2 is diced, two thin adhesive sheets 11a and 11b are laminated;' and the semiconductor wafer 2, on which a number of semiconductor elements 1 are lattice-like formed, are stuck onto the upper side adhesive sheet 11a. In the above-mentioned state, the semiconductor wafer 2 is cut by a dicer 5 for each element 1, and the prescribed remaining margine (b) is left on the upper adhesive sheet 11a. When each semiconductor element 1 is going to be picked up after the dicing operation has been conducted, the lower adhesive sheet 11b is exfoliated, the upper adhesive sheet 11a is radially expanded toward outside, and then each semiconductor element 1 is picked up.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a dicing method,
More specifically, the present invention relates to a dicing method for dividing a semiconductor wafer into individual elements by cutting with a dicer in the manufacture of semiconductor devices.

[0002]

2. Description of the Related Art A semiconductor device is generally manufactured collectively from a semiconductor wafer having a large number of semiconductor elements formed in a grid pattern. In the manufacture of this semiconductor device, a large number of semiconductor elements are formed on the semiconductor wafer, and then the semiconductor wafer is divided into individual elements by cutting with a dicer.

A conventional example of a dicing method for dividing the semiconductor wafer into each element will be described below.

First, as shown in FIGS. 4 and 5, a semiconductor wafer (2) having a large number of semiconductor elements (1) is attached to a relatively thick adhesive sheet (3), and the adhesive sheet (3 ) Is positioned and fixed on the stage (4) by vacuum suction or the like, the semiconductor wafer (2) is cut into a lattice shape by a rotating dicer (5) and divided into each element (1). At this time, the semiconductor wafer (2) is attached to the adhesive sheet (3)
As shown in FIG. 6, the semiconductor wafer (2) is completely cut by the dicer (5) and the adhesive sheet (3) is left in a state where a predetermined remaining amount (a) is left, as shown in FIG. Cut in.

After this dicing, the above-mentioned pressure-sensitive adhesive sheet (3)
Is extended by radially spreading outward, and each semiconductor element (1) is separated and spaced apart and picked up by a push-up pin and a suction collet,
It is taken out from the adhesive sheet (3) and mounted on a lead frame or the like.

[0006]

By the way, since the pressure-sensitive adhesive sheet (3) used in the above-mentioned dicing is relatively thick, the thickness of the pressure-sensitive adhesive sheet (3) varies widely, and the pressure-sensitive adhesive sheet formed by cutting the dicer (5). The variation of the remaining cost (a) in (3) also increases. If the residual amount (a) varies widely among the adhesive sheets (3) in this way, the stretched state will differ for each adhesive sheet (3) during pick-up after dicing, and the pick-up operation will be smooth. However, if the pressure-sensitive adhesive sheet (3) is thick, it is difficult to stretch the pressure-sensitive adhesive sheet (3) by radially spreading it when picking up.

Here, it is possible to use a thin adhesive sheet, but the adhesive force of the adhesive sheet during cutting by the dicer causes the thin adhesive sheet to be lifted up by being pulled by the moving dicer. There is a risk that the semiconductor elements may hit each other to cause chipping, or the semiconductor elements may scatter, so the strength is weak with a thin adhesive sheet,
There is a problem that good dicing cannot be performed.

Therefore, the present invention has been proposed in view of the above problems, and an object of the present invention is to minimize the variation of the remaining amount of each adhesive sheet and to make the adhesive sheet sufficiently strong. It is to provide a dicing method which can be secured.

[0009]

As a technical means for achieving the above object, the present invention provides a semiconductor wafer adhered on an adhesive sheet with a predetermined dicing for each element by cutting with a dicer for each element. When dividing while maintaining the remaining margin, a plurality of thin adhesive sheets are pasted together and a semiconductor wafer is pasted, and in that state the semiconductor wafer is cut by a dicer for each element and the adhesive just under the semiconductor wafer is cut. The sheet is characterized in that a predetermined remaining amount is left on the sheet, and then the adhesive sheet other than the adhesive sheet directly below the semiconductor wafer is peeled off.

[0010]

In the method of the present invention, since a plurality of thin pressure-sensitive adhesive sheets are laminated together, the thickness variation of the thin pressure-sensitive adhesive sheets is small. It is possible to reduce variations in the remaining amount remaining on the adhesive sheet by cutting with the dicer. In addition, since a plurality of pressure-sensitive adhesive sheets are stuck together during the dicing, sufficient strength can be secured against cutting by the dicer.

At the time of picking up after dicing, the adhesive sheets other than the adhesive sheet immediately below the semiconductor wafer are peeled off and only one thin adhesive sheet is spread, so that the spreading due to the spreading becomes easy.

[0012]

FIG. 1 shows an embodiment of a dicing method according to the present invention.
3 and 4 will be described. The same or corresponding parts as those in FIGS. 4 to 6 are designated by the same reference numerals, and the duplicated description will be omitted.

In the method of the present invention, as shown in FIG. 1, during dicing in the manufacture of a semiconductor device, a plurality of (two in the figure) thin adhesive sheets (11a) and (11b) are bonded together, and the adhesive layer on the uppermost layer is adhered. A semiconductor wafer (2) having a large number of semiconductor elements (1) formed in a grid pattern is attached to a sheet (11a), and in that state the semiconductor wafer (2) is diced (5) for each element (1). Then, the adhesive sheet (3) immediately below the semiconductor wafer (2) is left with a predetermined remaining amount (b) as shown in FIG.

Here, since the pressure-sensitive adhesive sheets (11a) (11b) are thin, variations in the thickness are small. For example, when two thin pressure-sensitive adhesive sheets (11a) (11b) are pasted, When compared with a thick PSA sheet having an equivalent thickness, it is less than half the thickness variation of the thick PSA sheet. Therefore, when two thin adhesive sheets (11a) and (11b) are laminated together, they have the same overall thickness as a conventional thick adhesive sheet, but the thickness variation is small, so It is possible to reduce the variation of the remaining margin (b) in the adhesive sheet (11a) remaining due to the cut by (5) as much as possible. Also, since the entire thickness of the adhesive sheet (11a) (11b) at the time of this dicing is large, sufficient strength can be secured against the cut of the dicer (5), and the adhesive force enables the dicer (5) to move. Tucked adhesive sheet (11a) (11b)
Cannot be lifted.

On the other hand, after the above dicing, as shown in FIG. 3, the pressure-sensitive adhesive sheet other than the pressure-sensitive adhesive sheet (11a) directly below the semiconductor wafer (2), that is, the pressure-sensitive adhesive sheet (11b) of the lowermost layer is peeled off, and then the pressure-sensitive adhesive sheet. Each semiconductor element (1) is stretched by radially spreading (11a) outward.
In a state where they are separated and arranged separately, they are picked up by a push-up pin and a suction collet, taken out from the adhesive sheet (11a) and mounted on a lead frame or the like.

At the time of this pickup, a thin adhesive sheet (11
Since a) is only one sheet, it is easy to stretch it by spreading, and as described above, the remaining amount (b) of the adhesive sheet (11a) is uniform without variation among the sheets, The picking-up operation can be performed smoothly without any difference in the extended state.

[0017]

According to the dicing method of the present invention,
At the time of dicing, the remaining amount of the adhesive sheet can be made uniform for each sheet, and at the time of pickup after the above dicing, the stretched state due to the spreading of the adhesive sheet can be made uniform and a smooth pickup operation can be performed. It will be possible. Further, since a plurality of adhesive sheets are attached at the time of dicing, it is possible to secure sufficient strength against the cut of the dicer, and at the time of pickup, since only a thin adhesive sheet is used, the extension of the adhesive sheet is possible. Is also very easy. Therefore, the workability and the yield in the dicing and the pickup are significantly improved, and it becomes easy to provide a good quality semiconductor device.

[Brief description of drawings]

FIG. 1 is a side view of an adhesive sheet, a semiconductor wafer and a dicer showing an embodiment of the method of the present invention.

FIG. 2 is a partially enlarged sectional view showing a cut state of a semiconductor wafer and an adhesive sheet by a dicer.

FIG. 3 is a partially enlarged cross-sectional view showing a state in which the lowermost pressure-sensitive adhesive sheet is peeled off during pick-up after dicing.

FIG. 4 is a plan view of an adhesive sheet, a semiconductor wafer, and a dicer showing a conventional example of a dicing method.

5 is a side view of FIG.

FIG. 6 is a partially enlarged sectional view showing a cut state of a semiconductor wafer and an adhesive sheet by a dicer.

[Explanation of symbols]

 1 Semiconductor element 2 Semiconductor wafer 5 Dicer 11a, 11b Adhesive sheet b Remaining cost

Claims (1)

[Claims] 1. A plurality of thin adhesive sheets are attached to each other when a semiconductor wafer adhered on the adhesive sheet is divided into each element by cutting with a dicer while maintaining a predetermined remaining amount on the adhesive sheet. Affix the semiconductor wafer on top of it, and in that state cut the semiconductor wafer for each element with a dicer to leave a predetermined remaining margin on the adhesive sheet directly under the semiconductor wafer, and thereafter, except for the adhesive sheet directly under the semiconductor wafer. A dicing method, characterized in that an adhesive sheet is peeled off.