JPS60249346A - Method of elongating semiconductor wafer - Google Patents

Abstract

PURPOSE:To facilitate the increase in speed and efficiency of pellet mounting and the simplification of facilities by a method wherein a wafer finished in pellet formation is adhered on a flexible sheet and sub-divided into pellets, and the sheet is elongated alternately in two orthogonal directions. CONSTITUTION:After a wafer 8 is adhered on a sheet 7, it is processed so as to be sub-divided into pellets 9, 9.... The sheet 7 is elongated in a fixed amount by being stretched for a given time by the same force first by two opposed clampers 11a and 11a in X and -X directions at the same time over a ring 10. Next, the sheet 7 is elongated in a fixed amount by being stretched for a given time by the same force by the other opposed clampers 11b and 11b in the Y and -Y directions at the same time with tension kept fixed in the X-direction. These actions are repeated at required times alternately in the X and Y directions. This manner facilitates the positioning of pellets at pickup positions by the sure speading of the respective pellets 9, 9... in lattice form. Accordingly, the increase in speed and efficiency of the pellet mounting machine and mechanical simplification can be easily contrived.

Description

DETAILED DESCRIPTION OF THE INVENTION A.1 Objective of the Invention 1.1 Purpose of the Invention This invention is to divide a semiconductor wafer pasted onto a sheet into a plurality of semiconductor pellets and stretch them to form semiconductors separated from each other. The present invention relates to a semiconductor wafer stretching method using a sheet in a pellet mounting process in which pellets are pink-amplified and mounted one by one on a heat sink or the like.

Conventional technology ■ In the pellet mounting process in the manufacture of general semiconductor devices, semiconductor wafers are pasted onto a single stretchable sheet, and semiconductor pellets are formed on the sheet in a lattice pattern in advance. Cutting or cutting along the pellet division lines so that the pellets can be subdivided into sections; stretching the sheet so that the semiconductor wafers are spaced apart from each other by a sufficient distance so that each semiconductor pellet can be taken out by a collet as described below; Semiconductor pellets are picked up one by one by a vacuum suction type collet from the sheet, and then supplied to a heat sink or the like and mounted.

The above-mentioned sheet stretching work is carried out by, for example,
Although it is shown in Publication No. 82, a concrete example that has been commonly used in the past will be explained with reference to FIGS. 6 to 9. First, as shown in FIG. A semiconductor device-wafer (2) with semiconductor pellets formed thereon (hereinafter referred to as a wafer) is attached to the center of a certain sheet (1) of soil, and the depth of the cutting groove is cut on the dividing line between the pellets of the wafer (2). The back side of the sheet (1) is cut into half caps smaller than the thickness dimension or through-cuts into individual pellets so that each semiconductor pellet can be subdivided, and the back side of the sheet (1) is cut as shown in FIGS. 7 and 8. Place the wafer (2) in the center on the sheet stretching circular ring (3);
Hold the peripheral edge of the sheet (1) using the circular clamper (4).
(4) and pull it below the ring (3). Then, the sheet (1) is stretched in a radial state on the ring (3), and in response to this stretching, each semiconductor pellet (hereinafter referred to as a pellet) (5) (5) on the wafer (1) becomes in a radiant state. Separate. When the distance between the pellets (5) (5) and - reaches a predetermined value, the stretching of the sheet (1) is stopped and the peripheral edge of the sheet (1) is placed on the outer peripheral surface of the ring (3) as shown in Figure 9. For example, it is fixed with a rubber ring (6). After that, the sheet (1) is stretched and fixed on the ring (3) in Figure 9.
) The pellets (5) (5L-) are adsorbed and peeled off one by one using a vacuum suction type collet (not shown), and then supplied to an external heat sink or the like for pellet mounting.

1 point When stretching the sheet (1) radially on the circular ring (3), the sheet (1) on the circular ring (3) is stretched from the center to the periphery. Since the elongation rate is larger in the case of , the plurality of pellets (5) (5), - formed in a grid pattern in two orthogonal x-y directions on the wafer (2) on the sheet (1) inevitably meander. The pellets were spread out, and the spacing between the pellets and the direction of the pellets were uneven. Therefore, after stretching,
When adsorbing pellets (5) (5)- from sheet (1) with a collet, alignment of one pellet (5) to be adsorbed requires three elements: the XSY direction and the tilt angle θ, making alignment complicated. It requires an expensive mechanism and a considerable waiting time, which makes it difficult to make pellet mounts faster, more efficient, and simpler.

The present invention has been made in view of the above-mentioned conventional problems, and the technical means of the present invention to solve these problems is to form a pellet-formed wafer into a stretchable sheet. There is a process in which the wafer is finely divided into pellets by attaching the wafers to the top, and a process in which the peripheral edge of the sheet to which the wafers are attached is held in place and tension is applied alternately in two directions orthogonal to the wafer's pellet arrangement. It involves the step of stretching alternately in two directions.

False 1 - According to this technical means, the wafer is pulled alternately only in the direction in which the pellets are arranged, so the interval between the pellet groups in the direction in which the pellets are arranged increases alternately by a predetermined amount, resulting in the formation of the final pellet group 7). The array remains grid-like. Therefore, when taking out pellets from the sheet after stretching, the position of the pellets is almost constant, making it easy to align the pellets.

An embodiment of the present invention is shown in FIGS. 1 and 2, and the operation thereof will be sequentially explained below with reference to FIGS. 3 to 5.

In Figures 1 and 2, (7) is a rectangular stretchable sheet, (8) is a wafer with pellets attached to the center of the sheet (7), and wafer (8) is a sheet ( 7), then pellet (9) in the same manner as before.
(9) It is processed so that it can be subdivided into parts. (10) is a rectangular ring for sheet stretching, (Ila) (ll
a) (llb) (llb) is sheet (7) 4
This is a clamper that independently clamps the peripheral edge of the side.

The wafer (8) is a pellet (9) on the sheet (7) above.
(9) - The arrangement direction (X direction and Y direction) of sheet (7
), and after processing the wafer (8) so that it can be divided into pellets, the sheet (7) is placed on a rectangular ring (lO), with the wafer (8) placed in the center of the ring, and the sheet (8) The four sides of ring (10) are placed along the four sides of ring (10). There are also rings (10) before and after installing this seat.
Use a clamper (lla
) (lla) (llb) (llb). After that, the present invention provides a sheet (10) on the ring (10).
7) Two clampers (lla) (Ila) facing each other
), first pull it in the X and -X directions with the same force for a certain amount of time and stretch it by a certain amount, then hold the tension in the X direction constant and use another opposing clamper (llb ).
(llb''), the sheet (7) is simultaneously pulled in the Y and -Y directions with the same force for a certain amount of time and stretched by a certain amount.This operation is repeated a predetermined number of times alternately in the X and Y directions.

Now, the clampers (lla) (lla) in the X and -X directions are
), if you stretch sheet (7) first,
Each pellet (9) of the wafer (8) as shown in Figure 3.
(For 91-, only the interval in the Y direction expands and expands. At this time, the sheet (7) is pulled only in one direction, so the sheet (7)
) The elongation rate of the portion between the two clampers (lla) (lla) is equalized throughout, and therefore the interval in the Y direction of each pere throat (9) (9)- becomes approximately constant. Next, the clamper in the Y, -YyJ direction (llb > (Ilb)
When the sheet (7) is stretched, as shown in Fig. 4, the pellet group that spread in the X and -X directions spreads in the Y and -Y directions, and the interval in the 9
1- spreads in a grid-like arrangement that is spaced apart in both x and y orthogonal directions. By repeating this process alternately a plurality of times with a small amount of spreading in the X-Y directions each time, each pellet (9) (9L-) can be reliably spread while remaining in a lattice shape.

When such sheet stretching is completed, for example, the fifth
As shown in the figure, a rectangular retaining frame (12) that is slightly larger than the ring (10) is press-inserted onto the outer periphery of the ring (10) through the seat (7), and the ring (10) is inserted while the seat (7) is stretched. Fixed to.

After that, pink amplify the pellets (9) (9) from the sheet (7) on this ring (10) one by one using a collet in order to mount them.

Effects of the Invention According to the present invention, a wafer on a sheet is alternately stretched through the sheet in only one arrangement direction of the pellets and then only in another arrangement direction, and the pellets are adsorbed by a collet and mounted on a heat sink or the like. This makes it easy to align the pellets at the pick-up position, making it easy to increase the speed, increase efficiency, and simplify the mechanism of the pellet mount machine.

[Brief explanation of drawings]

1 and 2 are a plan view showing an embodiment of an apparatus for carrying out the method of the present invention, and a side view of the apparatus along line A-A after sheet stretching. 6 to 9 are for explaining a conventional wafer stretching method, in which FIG. 6 shows a sheet, and FIG. 9 shows a side view of the apparatus shown in FIG. 7 after the sheet is stretched. (7)...-sheet, (8)...-semiconductor wafer, (9
)--a semiconductor pellet. Part 1 - Simple 21 Ikkun-36;K1115-sB figure 91

Claims (1)

[Claims] (1) A step in which a semiconductor wafer on which a plurality of semiconductor pellets are formed in a lattice arrangement is attached to a stretchable sheet, and the semiconductor wafer is subdivided into semiconductor pellets, and the periphery of the sheet is sandwiched. 1. A method for stretching a semiconductor wafer, comprising the step of stretching the sheet by applying tensile force to the semiconductor wafer alternately in two directions perpendicular to the arrangement of pellets on the semiconductor wafer.