JPH0245579A - Fixing of wafer sheet - Google Patents

Abstract

PURPOSE:To fix a wafer sheet on a wafer frame with uniform tension by extending a wafer sheet over the whole area of a circular hole of an auxiliary plate and pressing the wafer sheet by passing a pressing means through the circular hole of the auxiliary plate. CONSTITUTION:An auxiliary plate 3 to be used in the present process has a circular hole 3a and an attaching face 3b at the circumference of the circular hole. A wafer frame 2 is provided with a circular hole 2a smaller than the circular hole 3a of the auxiliary plate 3 and an attaching face 2b is formed at the circumference of the circular hole 2a. The above auxiliary plate 3 is placed on the attaching side 2b of the wafer frame 2 capable of holding the auxiliary plate 3 in such a manner as to almost coincide the centers of said circular holes 2a and 3a with each other. A wafer sheet 1 is extended over the circular hole 3a of the auxiliary plate 3 and is pressed with a pressing means 4 to fix the sheet on the circular hole 2a of the wafer frame 2.

Description

[Detailed Description of the Invention] [Summary] Regarding a method of pasting a wafer sheet with an adhesive layer on one side to a flat wafer frame provided with a circular shape, the semiconductor wafer pasted on the wafer sheet is used with a dicing saw. The purpose of this is to reduce uneven stretching of the wafer sheet that occurs due to cutting halfway through the film thickness of the wafer sheet when it is fully cut, and has a circular hole and a surface to be adhered at the periphery of the circular hole. The auxiliary plate is equipped with an auxiliary plate, a circular hole smaller than the circular hole of the auxiliary plate, and a surface to be adhered to the periphery of the circular hole.
It consists of a wafer frame that can be placed in two positions, and a pressing means that can be inserted through a circular hole in the auxiliary plate to press the surface to be adhered to the wafer frame. A wafer sheet is spread over the entire surface of the circular hole in the plate,
The weber sheet stretched over the entire surface of the circular hole of the auxiliary plate is pressed by a pressing means so as to be stretched over the circular hole of the wafer frame.

[Industrial application field]

The present invention relates to a method of attaching a wafer sheet for attaching a semiconductor wafer to a wafer frame having circular holes formed in a metal plate.

It is well known that automation in all aspects of semiconductor manufacturing processes is rapidly expanding in recent years, and this also applies to the die bonding process in which semiconductor chips are bonded to die pads of lead frames.

In this automation of die bonding, orderly arrangement of semiconductor chip knobs is a requirement for reducing chip pick-up errors by the die collet and accurately aligning the chip frame to the die pad.

BACKGROUND ART A commonly used method for separating a semiconductor wafer after wafer processing into chips is to perform full-cut dicing using a dicing saw on a semiconductor wafer attached to a wafer sheet stretched over a wafer frame.

Full-cut dicing using dicing two cuts a wafer sheet stretched with a certain tension to the middle of the film thickness.

Therefore, since the cut portion of the wafer sheet stretches due to tension, it is important to stretch the wafer sheet on the wafer frame with even tension.

[Conventional technology]

In the conventional wafer sorting method, a wafer sheet cut to a predetermined size is stretched to a wafer frame by pulling it with a predetermined force from front to back, left to right, and from side to side.

When the wafer sort is stretched by such a method, the tension becomes approximately uniform in the direction in which the wafer sheet is pulled, but not in the direction of the outer periphery of the circular hole in the wafer frame.

[Problem to be solved by the invention]

Therefore, when a semiconductor wafer bonded to a wafer sheet bonded by the above method is subjected to full-cut dicing, uneven elongation occurs in the cut portion of the wafer sheet.

As a result, the arrangement of the chips is disturbed, resulting in problems such as a pick-up error of 1,000 knobs by the collet during die bonding, and the inability to perform die bonding with high positional accuracy with respect to the die pad of the lead frame.

The present invention addresses the problems mentioned in section 2 above, and provides a method for tensioning a wafer sheet to a wafer frame so that even if a semiconductor wafer attached to a wafer sheet is fully cut with a dicing saw, the curvature of the chip arrangement is reduced. The purpose is to provide a method for

[Means to solve the problem]

FIG. 1 is a diagram explaining the principle of the present invention.

In the figure, an auxiliary plate 3 has a circular hole 3a and a surface 3b to be adhered on the peripheral edge of the circular hole 3a, a circular hole 2a smaller than the circular hole 3a of the auxiliary plate 3, and a target surface 3b on the peripheral edge of the circular hole 2a. Side 2
The wafer frame 2 is equipped with
An auxiliary plate 3 is placed on the wafer frame 2 on the wafer surface 2b side, and the wafer sheet 1 is stretched into the circular hole 3a of the auxiliary plate 3. Then, by pressing the wafer sheet 1 with the pressing means 4, the wafer sheet 1 is stretched over the entire surface of the circular hole 2a of the wafer frame 2.

[For production]

In the present invention, the wafer sheet 1 is stretched over the entire surface of the circular hole 3a of the auxiliary plate 3, and the pressing means 4 is inserted through the circular hole 3a of the auxiliary plate 3 to press the wafer sheet 1.
While applying tension to the wafer sheet 1 in the direction of the outer circumference of the circular hole 3a of the auxiliary plate 3, the wafer sheet 1 is stretched over the entire surface of the circular hole 2a of the wafer frame 2. It is pasted to the entire circumference of the surface to be pasted 21) at the peripheral edge.

As a result, the wafer sheet 1 stretched over the circular hole 2a of the wafer frame 2 has approximately equal tension in the outer circumferential direction of the circular hole 2a.

〔Example〕

The present invention will be explained in detail below with reference to FIG.

FIG. 2 is a partial side cross-sectional view of the sticking mechanism of the wafer sheet sticking apparatus according to the Ichiki embodiment of the present invention.

Reference numeral 5 denotes a table, and the wafer frame 2 on which the auxiliary plate 3 is placed can be placed on the top surface of the table 5.

Reference numeral 6 denotes an adhesive member, which includes a rotating shaft 6a that can move up and down in six directions perpendicular to the table 5, an arm 6b projecting from the tip of the rotating shaft 6a in the direction of lateral force, and a roller 6C at the tip of the arm 6b.
are connected and configured. Roller 6c is arm 6
It can be moved around the connecting shaft to b, and moves up and down in six directions in conjunction with the downward movement of the rotating shaft 6a in six directions.

Reference numeral 7 denotes a cutter member, which includes a rotating shaft 7a that moves up and down in a direction perpendicular to the table 5, an arm 7b extending laterally from the tip of the rotating shaft 7a, and a cutter 7 at the tip of the arm 7b.
It is constructed by concatenating 0's.

The cutter 7C is movable around the connecting shaft to the arm 7b, and moves up and down in the B direction in conjunction with the up and down movement of the rotary shaft 7a in the L3 direction.

In such an apparatus configuration, the wafer frame 2 is placed on the upper surface side of the table 5 with the adhered surface 2b facing upward.

Furthermore, the wafer sheet 1 shown by the dotted line on the upper surface side of the wafer frame 2 is attached to the adhesive surface (1b) of the wafer sheet 1.
The attached auxiliary plate 3 is placed so that the wafer sheet 1 is facing upward.

At this time, the centers of the circular holes (3a, 2a) provided in the auxiliary plate 3 and the wafer frame 2G are substantially coincident with each other, and the rotation axes (6a, 7a) of the wafer sheet sticking device are
).

Next, the rotating shaft 6a is moved downward in six directions by a drive device (not shown), and the wafer sheet I pasted on the auxiliary plate 3 is moved to the pasted surface of the wafer frame 2 by the roller 6C.
When the rotating shaft 6a is rotated by a drive device (not shown) after pressing the wafer frame 1 to the surface 2b of the wafer frame 2, the roller 6C also rotates about the rotating shaft 6C while pressing the wafer frame 1 against the adhered surface 2b of the wafer frame 2. .

As a result, the wafer sheet l is spread over the entire surface of the circular hole 2a of the wafer frame 2, and is also stuck to the surface 2b of the wafer frame 2 to be stuck.

Next, a drive device (not shown) stops the rotation of the rotating shaft 6a and moves the rotating shaft 6a upward in the A direction.

After that, the rotating shaft 7a is moved to B by a drive device (not shown).
The blade edge of the cutter 70 is brought into contact with the cut portion 8 of the wafer sheet l attached to the adhered surface 2b of the wafer frame 2 by moving the cutter 70 downward, and then the cutter 70 is cut by a drive device (not shown). The rotating shaft 7a is rotated to cause the cutter 70 to roll around the rotating shaft of the rotating shaft 7a.

As a result, the wafer sheet l is cut at the cutting section 8.

After the cutting is completed, the rotating shaft 7a stops rotating by a drive device (not shown) and is moved upward in the direction B, thereby completing the adhesion of the wafer sheet 1 to the wafer frame 2.

〔Effect of the invention〕

As explained above, according to the present invention, even if a semiconductor chip is fully cut with a dicing saw, the bending of the chip arrangement is reduced, and in automatic guide pounding, it is possible to reduce mistakes in picking up chips by the collet and to place them in the specified position. Accurate die bonding is possible.

[Brief explanation of the drawing]

FIG. 1 is a detailed explanation of the present invention. FIG. 2 is a partial side sectional view of a sticking mechanism of a wafer sheet sticking apparatus according to an embodiment of the present invention. In the figure, (2) indicates the wafer sheet 1a is an adhesive layer, 2 indicates a wafer frame, 2a and 3a indicate circular holes, 2b and 3b indicate surfaces to be adhered, 3 indicates an auxiliary plate, and 4 indicates a pressing means. ４嬬輯ya 3b 橡l产子弯屯目fJtψJ へ [l] Cross-sectional view Figure 1

Claims (1)

[Scope of Claims] A method of adhering a wafer sheet having an adhesive layer on one side to a flat wafer frame having a circular hole, the method comprising: providing a circular hole (3a) and forming a peripheral edge of the circular hole (3a); an auxiliary plate (3) having an adhered surface (3b); and the auxiliary plate (3).
A circular hole (2a) smaller than the circular hole (3a) is provided, a surface to be adhered (2b) is provided at the peripheral edge of the circular hole (2a), and the auxiliary plate (3) is attached to the circular hole (2a, 3a). a wafer frame (2) that can be placed so that the centers of the wafer frames (2) and wafer frames (2) are approximately aligned; 2b), the auxiliary plate (3) is placed on the surface to be adhered (2b) of the wafer frame (2), and the auxiliary plate (3) is pressed. The circular hole (3
a) applying the wafer sheet (1) to the circular hole (2a) of the wafer frame (2) by pressing the wafer sheet (1) with the pressing means (4); A wafer sheet pasting method characterized by: