KR940000495B1 - Apparatus for adhering wafers - Google Patents

Abstract

The apparatus consists of a pad shaft sliding within the linear bearing of the upper ram, a vacuum chuck body on which a vacuum guiding groove for suction-holding the upper wafer is radially formed, an O-ring for forming dove tail-like grooves on the upper part of the driving outer wheel, and a spherical vacuum chuck for suction-holding the lower wafer.

Description

Wafer Bonding Machine

1 is an assembly view of the present invention,

(a) is a top view of the present invention.

(b) is a side view of the present invention.

2 is an operating state diagram of the present invention,

(a) is sectional drawing which showed the state in which the lower wafer was adsorb | sucked to the spherical surface by the vacuum chuck.

(b) is a side cross-sectional view showing a state in which the upper wafer is downwardly in contact with the spherical lower wafer.

(c) is a cross-sectional view showing a state in which the lower wafer is relaxed and in contact with the upper wiper.

* Explanation of symbols for main parts of the drawings

1: base plate 2: vacuum chuck body

2a: vacuum guide groove 3: operation

4: Recovery spring 5,23: O-ring

6: upper ram 7: straight bearing

8: Deflation 10: Pressing spring

11: sliding block 12: guide shaft

13: guide bearing 14: stopper

15: handle cam 15a:

16: compression spring 17: idle roller

18,18a, 18b: wafer 19: white paper

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wafer bonding apparatus for minimizing adhesion failure due to mixing of bubbles in a semiconductor manufacturing process in which two wafers are bonded to each other and laminated.

In the conventional wafer bonding apparatus, it is virtually impossible to expect uniform contact across the entire surface of the wafer due to the unevenness of the wafer itself and the fine bending when the wafers on the plane are bonded to each other. In the process of spreading the adhesive by the multi-point contact even when pressed in the air bubble (air trap) is inevitable, there was a problem that acts as a yield reduction factor of the semiconductor manufacturing process.

The present invention for solving such a conventional problem is that one of the two wafers to be bonded is adsorbed by the upper vacuum pad and the other is sucked into the sphere by the lower spherical vacuum chuck so that the upper wafer is rearward A device that allows the lower wafer adsorbed to the spherical surface to be uniformly attached to the upper wafer by gradually spreading the vacuum while being pressed along the linear bearing and guide axis of When described in detail based on the accompanying drawings as follows.

Figure 1 shows the assembled state of the present invention, (a) is a planar assembly view from above, (b) is a side assembly view seen in cross section.

Figure 2 shows the operating state of the present invention (a) is a cross-sectional view showing a state that the wafer is sucked (Chucking) to the spherical surface by the lower vacuum chuck. (b) is a side view showing a state in which the upper wafer is in contact with the wafer on the lower spherical surface downward. (c) is a schematic diagram showing the state where the lower spherical wafer is adhered to the upper wafer while spreading on the plane by slowly releasing the vacuum.

Looking at the configuration of the present invention is a spherical-shaped vacuum chuck that is fixed and sealed with a base plate (O-ring (2 3) on the base plate ((1)) and the radial vacuum guide groove (2a) The body (2) is mounted in a movable outer ring (3) and a recovery spring (4) sliding the vacuum chuck body (2), a groove tail-shaped groove on the movable outer ring (3) O-ring O-ring (5) for holding seal, pad shaft (8) and vacuum pad sliding in linear bearing (7) on upper ram (6) ( 9), so that the pressure spring (10), the sliding block (11) equipped with an upper ram (6), the sliding block (11) equipped with a pressing force during wafer bonding, can smoothly move up and down while maintaining precision. Guide shaft 12 and guide bearing 13, stoppers 14 and sliding blocks 11 for positioning the wafers 18 and 18a to be bonded in a fixed state. Idle roller 17 for smoothing the movement between handle cam 15 and compression sieve 16, handle cam 15 and sliding block 11 for vertical movement. , Hinge 19 and bracket 20 for mounting handle cam 15, flexible pad for generating vacuum to vacuum pad 9 and vacuum chuck 21, 22) and various fittings.

The wafer 18 is placed on the movable outer ring 3 by placing the cut surface of the wafer 18 in contact with the stopper 14 located on the outer surface of the sliding block 11 while the vacuum pump is in operation. The upper wafer 18a is placed on a vacuum pad 9 mounted on an O-ring 5 and attached to the end of a pad shaft 8 that slides in a straight bearing 7 of the upper ram 6. The upper wafer 18a is adsorbed to the bottom of the vacuum pad 9 and the lower wafer 18 is vacuumed by the vacuum suction. When the sealed space is formed by the movable outer ring 3 and the wafer 18 through the vacuum guide groove 2a formed in the suction hole, the suction force of the wafer 18 is absorbed by the movable outer ring (2). It acts as a force to lower the 3) is to be adsorbed to the sphere according to the spherical shape of the upper body (2) of the vacuum chuck (2).

Here, the spherical surface of the upper part of the vacuum chuck body 2 may be a curvature such that the unevenness of the wafer itself and the curvature of the wafer itself can be eliminated.

When the lower wafer 18 is sucked into the spherical shape, the idler roller installed on the side of the sliding block 11 on which the upper ram 6 is mounted is pulled forward by the handle cam 15. 17) and the sliding block 11 and the upper ram 6 mounted thereon are lowered by the circular guide surface 15a of the handle cam 15 and the upper wafer 18a is lowered. The point contact is made to the spherical wafer 18b. At this time, if the upper ram (6) is continuously lowered, the upper wafer (18a) is in contact with the lower wafer (18b) can not be lowered any more, so the pad shaft (8) of the pad shaft (8) of the vacuum pad (9) Since the retreat is guided by the linear bearing 7 on the upper ram 6, the pressure spring 10 installed on the upper surface of the vacuum pad 9 is compressed to act as a wafer pressing force. In addition, when the handle cam 15 is fully pulled forward, the guide shaft 12 of the sliding block 11 is moved by the relative position of the hinge axis 19 of the handle cam 15 and the idle roller 17. ) The restoring force of the compression spring 16 installed on the outer surface acts so that the upper ram 6 is self-knocked so as to remain in contact with the wafers 18 and 18b.

In this state, when the needle valve installed at any position of the vacuum pipe line is slowly operated to release the vacuum state, the lower wafer 18b, which has been adsorbed on the spherical surface, is gradually restored to a flat state, and the wafer is concentrically drawn from the center to the outside. It will bond uniformly. At this time, the movable outer ring 3 is restored to its original position by the recovery spring 4 as the wafer 18b is restored. Here, the adhesive surface of the wafer is usually hydrophilic so that the adhesion can be made smoothly.

After the bonding of the wafer is completed, the handle cam 15 is returned to its original position, and the sliding block 11 and the upper ram 6 are restrained by the restoring force of the compression spring 16 installed on the lower surface of the sliding block 11. Upon return to the original position, the bonded wafers 18 and 18b are placed on an O-ring 5 on the movable outer ring 3. According to the present invention, the vacuum introduction process of the upper vacuum pad 9 and the lower vacuum chuck (including the vacuum chuck Body 2 and the movable outer ring 3) is carried out in a flexible hose (21, 22). ) And the vacuum introduction hole in the upper ram (6) and the vacuum introduction hole in the base plate (1) to be integrally introduced. Instead of manually moving the sliding block 11 up and down by a handle cam 15, a ball screw is mounted on the sliding block 11 to rotate the ball screw with a motor. The sliding block 11 may be automatically moved up and down.

Therefore, in order to minimize the back surface of the adhesive surface of the wafer, the back side of the wafer is not sucked by vacuum suction and to minimize air trap caused by multi-point contact when bonding two wafers. Improved technology in the semiconductor manufacturing process by vacuum-sorption of one wafer into a spherical shape, and then gradually restoring the spherical wafer to a flat surface in a state where it is in point contact with the other flat wafer. Yield improvement is effective.

Claims (3)

In the process of bonding two wafers to manufacture a semiconductor, a top of the sliding block 11, upper ram Ram 6, which moves up and down along the guide shaft 12, and a straight line on the upper ram 6; A spherical vacuum chuck radially provided with a vacuum suction means for guiding the upper wafer 18a by installing a pad shaft 8 sliding in the bearing 7 and a vacuum pad 9 at the end thereof. Body, vacuum body (2) fixed to the base plate (1) to seal (O-ring) 23, the outer ring sliding close to the sliding (3) Spherical vacuum adsorption means for adsorbing the lower wafer 18 into a spherical shape using an O-ring 5 and a vacuum chuck mounted thereon by forming a groove of a dove tail shape in the upper part of the The needle 18 provided with the wafer 18b in point contact with the upper wafer 18a on the lower spherical shape, and a needle valve provided at an arbitrary position on the vacuum pipe. Slowly manipulate When releasing the vacuum while the spherical wafer (18b) in a plane restore a wafer bonding, it characterized in that the adhesive until a uniform circular motion to the upper wafer (18a) concentric with the device. The stopper 14 is provided on the outer surface of the sliding block 11 so as to be contacted at two points on the wafer circumference so that the upper and lower wafers 18 and 18a are energized to be bonded. Wafer bonding apparatus characterized in that. The handle cam according to claim 1, wherein the idler roller 17 of the sliding block 11 on which the upper ram Ram 6 is mounted is formed and has a circular guide surface 15a on the side thereof. 15) when the handle cam (15) is pulled forward so that the sliding block (11) and the upper ram (6) are lowered along the guide shaft (12) and the idle roller (17) shaft and the handle cam. (Ha ndle Cam) (15) Wafer bonding apparatus characterized in that the self locking by the action of the restoring force of the compression spring 16 on the lower surface of the sliding block 11 by the relative position of the hinge shaft (19). .