JP2000127034A - Wafer sticking method to mount plate and its device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent air from entering between a wafer and a mount plate and reliably stick the water to the mount plate to its edge when the wafer coated with an adhesive is stuck to the mount plate. SOLUTION: A pressurized fluid is guided into a hollow pad 12 protruded downward at the center. A wafer 3 is gradually pressed to a mount plate 1 from the center toward the outer periphery while the inside of the pad 12 is kept at the nearly constant pressure by the pad 12. When the pad 12 is brought into contact with the whole face of the wafer 3, the pressurized fluid in the pad 12 is released, a guide plate 23 having the size to cover the whole face of the wafer 3 is put on the back face of the pad 12, and the wafer 3 is pressed by the pad 12 and the guide plate 23, thereby the wafer 3 is reliably stuck to the mount plate 1 to its edge.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting plate for uniformly polishing a wafer such as a semiconductor wafer when the wafer is polished smoothly. The present invention relates to a method and an apparatus for bonding a wafer to a wafer.

[0002]

2. Description of the Related Art In a semiconductor manufacturing method, when a wafer is polished, a wafer is stuck to a mounting plate with an adhesive and a polishing process is performed. Has been requested. For this reason, a method of applying a thin adhesive to the wafer, placing the adhesive applied side down on a mount plate, and pressing the wafer from the upper surface has been adopted. If air or the like is taken in between the wafer and the mounting plate, a high flatness cannot be obtained. Therefore, as a method for removing the air, a method of gradually pressing the wafer from the center to the periphery of the wafer is used. .

In the case of pressing with a stamp as described above, a pad having a substantially spherical surface with the center of the pressing surface protruding downward and the periphery curved in an arc shape is used, and the pad itself is hollow or medium made of an elastic material such as silicon rubber. It is really composed. The hollow pad adjusts the amount of air introduced into the pad so that the pressure becomes almost constant from the start to the end of pressing, so that the air gradually escapes from the center of the wafer toward the periphery.
It is difficult to take in air, but when pressing is completed, the center of the pressing surface of the pad is inverted and recessed inside the hollow body, and when the stamp rises, the center of the pressing surface is in a vacuum state, In some cases, a force acts in a direction in which the wafer is lifted upward, which has an adverse effect on the attached state of the wafer.

When pressing the edge of a wafer,
The peripheral portion of the pressing surface of the pad has a large curvature, and the peripheral portion is depressed from the wafer edge so as to press the edge, so that the wafer edge may not be sufficiently pressed. When the pressing of the edge of the wafer becomes uncertain, the edge is in a state where it is slightly lifted from the mounting plate. . Such a drawback lies in the fact that the applicant of the present application has previously proposed the Japanese Utility Model 7-9375.
As described in Japanese Patent Application Laid-Open Publication No. H10-209, the improvement can be achieved by forming an upright wall at the base of the pad of the stamp so that a pressing force acts directly on the edge of the wafer, but the diameter of the wafer is 300 mm. When the diameter becomes larger, or more, there is a possibility that it is more difficult to surely press along the edge.

In the case of a solid pad, the wafer can be surely pressed from the center to the edge of the wafer, but the pressing surface gradually contacts the wafer like a hollow pad. Since the wafer is instantaneously pressed instead of being deformed, the removal of air between the wafer and the mounting plate is often insufficient. Therefore, as if the particles (particles) were mixed,
Bubbles are taken in the adhesive layer, and it is difficult to obtain a wafer with high flatness by polishing.

[0006]

The problem to be solved by the present invention is as follows.
When the wafer to which the adhesive has been applied as described above is placed on a mounting plate, and the wafer is pressed with a stamp and bonded to the mounting plate, air may be taken in between the wafer and the mounting plate. It is an object of the present invention to provide a bonding method and apparatus capable of bonding a wafer to a mounting plate in an extremely uniform state by pressing the wafer to the edge of the wafer without fail.

[0007]

According to the present invention, a wafer to which an adhesive has been applied is placed on a mounting plate, and the wafer is subjected to a pressurized fluid, and a resilient wafer whose center projects downward. In this method, the pad is gradually contacted from the center to the outer periphery of the wafer while the inside of the pad is kept at a constant pressure by the pressurized fluid. After the pad contacts the entire surface, the pressurized fluid in the pad flows out, the back surface of the pad is supported by a guide plate, and the wafer is pressed by the guide plate and the pad. A method for bonding a wafer to a wafer is provided to solve the above-mentioned problem.

Further, according to the present invention, a wafer coated with an adhesive is placed on a mounting plate, and the wafer is formed by an elastic hollow pad into which a pressurized fluid is introduced and whose center projects downward. In an apparatus for pressing and bonding to a mounting plate, a guide plate large enough to cover the entire surface of the wafer is provided inside the pad,
When the pad comes into contact with the entire surface of the wafer, the pressurized fluid in the pad flows out, and the guide plate is brought into contact with the back surface of the pad to press the wafer. An apparatus for bonding a wafer to a plate is provided to solve the above-mentioned problems.

[0009]

FIG. 1 shows a mounting plate (1);
One embodiment in which a wafer (3) coated with an adhesive (2) for bonding to the mounting plate (1) and a bonding apparatus of the present invention for pressing the wafer are separately illustrated is shown. It is shown. The above-mentioned device comprises a shaft (4) which is moved up and down by a driving means such as a fluid pressure cylinder such as an air cylinder or a motor cylinder (not shown) and a hole (5) for receiving the tip of the shaft (4). A bracket (8) attached to the shaft by tightening a holding piece (7) from the side with a bolt (6), and a bolt (10) connected to the bracket (8) via a liner (9). And a pad (12) attached to the lower surface of the attachment frame (11).
The mounting amount is changed by changing the screw-in amount of a plurality of adjusting screws (13) provided at appropriate positions of the bracket (8) and changing the distance between the liner (9) and the bracket (8) at the end of the screw. The mounting angle of the frame (11) can be adjusted.

The pad (12) is made of a resilient material such as silicone rubber and is hollow, and has a substantially spherical pressing surface (14) whose center protrudes downward and whose periphery is curved in an arc shape. Face (1
4) The thickness of the portion is relatively thick, for example, about 10 to 25 mm, preferably about 13 to 20 mm, and it is more preferable that a plurality of pads having different hardnesses are prepared and exchangeable. An upright wall (15) at the periphery of the pad (12) has a base end (16) bent inward to form a receiving groove formed in the mounting frame (11).
(17), and a ridge (19) provided on the mounting frame (11) is engaged with an upper concave groove (18) formed in the base end (16).

There is a lower groove (20) on the lower surface of the base end opposite to the upper groove (18) formed on the upper surface of the base end (16). A receiving groove (22) having an engaging edge (21) to be engaged with and fitting the inner tip of the base end (16) inward.
Guide plate (23) having bolts (27)
Installed in 1).

The guide plate (23) is provided inside the pad (12) as described above, and the surface facing the pad (12) is flat in the figure, but the center is gently downward. The outer diameter of the wafer may be slightly larger than that of the wafer (3) so as to cover the entire surface of the wafer to be pressed, for example, about several mm in diameter. It is good to form so that it may become large.

The guide plate (23) comes into contact with the rear surface of the pad (12) when the pad (12) comes into contact with the entire surface of the wafer (3) on the mount plate (1) as described later. Position. When the pad (12) abuts on the guide plate (23), a part of the pressurized fluid is prevented from being sealed between the pad and the guide plate, and the pad and the guide plate are pressed when the pad is pressed. Grooves (24) are formed vertically and horizontally on the lower surface of the guide plate (23) to allow the pressurized fluid to flow along the guide plate so that the pressurized fluid can quickly enter between them and the pad can be quickly restored. A flow port (25) through which the pressurized fluid flows is opened at a portion communicating with the groove on the side surface and the lower surface of the guide plate (23). The inner end of the circulation port (25) extends in the radial direction so as to communicate with a supply pipe (26) connected to the back surface of the guide plate (23).

As shown in FIG. 4, an annular groove (28) is formed so as to communicate with the groove (24)... On the lower surface of the guide plate (23).
May be formed, a flow opening (25) may be opened in the annular groove,
An annular groove is formed on the side surface of the guide plate so as to communicate with a distribution port opened on the side surface of the guide plate, and a plurality of vertical grooves are formed on the side surface of the guide plate so as to communicate with the annular groove. (Not shown). In the figure, the guide plate (2
3) also serves as a member for holding the pad (12) on the mounting frame (11), but a pad holding member (not shown) and a guide plate that contacts the back surface of the pad may be formed as separate members, In addition, the structure for holding the pad on the mounting frame can be an appropriate structure other than that shown in the drawing.

A supply pipe (26) connected to the guide plate (23)
Is connected to a pressurized fluid supply source such as an air compressor (not shown) and a pressurized fluid adjusting device (not shown) including a pressure sensor, a relief valve, a stop valve, etc., and presses the wafer. When the pad is brought into contact with the entire surface of the wafer, the flow of the pressurized fluid such as air is adjusted so that the inside of the pad becomes substantially constant pressure.
(25), it is controlled to flow out of the pad through the supply pipe (26).

Wafer (3) coated with adhesive (2)
Is mounted on the mounting plate (1) by a transfer robot or other appropriate means, and the bonding device faces the position where the center axis of the shaft (4) coincides with the center of the wafer (3).
When the shaft (4) is lowered by the driving means, the inside of the pad (12) gradually contacts from the center to the outer periphery of the wafer (3) while being pressurized to a constant pressure by the pressurized fluid. Then, the wafer is pressed against the mounting plate (1). When the pad (12) comes into contact with the entire surface of the wafer (3), the pressurized fluid in the pad (12) flows out as shown in FIG.
The guide plate (23) is brought into contact with the back surface of the wafer, and the wafer (3) is pressed in this state. Thereafter, the shaft (4) is raised by the driving means, and the pad (12) is restored by introducing a pressurized fluid to the state shown in FIG.

[0017]

According to the present invention, the pad is gradually contacted from the center to the outer periphery of the wafer while maintaining the inside of the pad at a constant pressure by the pressurized fluid, so that the entire surface of the wafer is brought into contact with the pad. After the pad comes into contact with the pad, the pressurized fluid in the pad flows out, the back surface of the pad is supported by a guide plate, and the wafer is pressed against the mounting plate by the guide plate and the pad. The air between the wafer and the mounting plate is gradually discharged from the peripheral portion of the wafer and is not taken into the adhesive layer of the wafer, and after uniformly pressing the entire surface of the wafer, The entire surface of the wafer is more strongly pressed by the guide plate and the pad which are large enough to cover the entire surface of the wafer, and can be reliably pressed to the edge of the wafer. There is no danger.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a relationship between a wafer and a mounting plate before bonding and an embodiment of the present invention.

FIG. 2 is a sectional view showing a state where the entire surface of the wafer is pressed.

FIG. 3 shows one embodiment of a guide plate, (A) is a plan view,
(B) is a bottom view, and (C) is a partially enlarged cross-sectional view.

4A and 4B show another embodiment of the guide plate, FIG. 4A is a partially enlarged bottom view, and FIG. 4B is a partially enlarged sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Mounting plate 3 Wafer 8 Bracket 11 Mounting frame 12 Pad 23 Guide plate

Claims (5)

[Claims] 1. A wafer coated with an adhesive is placed on a mounting plate, and the wafer is pressed by a resilient hollow pad into which a pressurized fluid is introduced and whose center projects downward. In the method of adhering to the pad, the pad is gradually contacted from the center of the wafer to the outer periphery while the inside of the pad is kept at a constant pressure by the pressurized fluid, and the pad contacts the entire surface of the wafer. Discharging the pressurized fluid to support the back surface of the pad with a guide plate, and pressing the wafer with the guide plate and the pad. 2. A wafer to which an adhesive has been applied is placed on a mounting plate, and the wafer is pressed by a resilient hollow pad into which a pressurized fluid is introduced and whose center projects downward. A guide plate large enough to cover the entire surface of the wafer inside the pad, and when the pad comes into contact with the entire surface of the wafer, pressurized fluid in the pad flows out and the pad A wafer bonding apparatus for mounting a wafer to a mounting plate, wherein the wafer is pressed by bringing the guide plate into contact with the rear surface of the wafer. 3. The apparatus for bonding a wafer to a mount plate according to claim 2, wherein a groove is formed on a surface of the guide plate so that a pressurized fluid flows. 4. The apparatus according to claim 2, wherein the surface of the guide plate is a flat surface. 5. The apparatus for bonding a wafer to a mounting plate according to claim 2, wherein the surface of the guide plate is a substantially spherical surface.