JP2000195897A - Flux transfer device and its transfer method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transfer method of flux capable of transferring the appropriate amount of flux only in the bump of a semiconductor chip and can improve yield by stable solder junction, and to provide a device. SOLUTION: A transfer roller 13 has a cushion 13b on a surface, it moves on a transfer stage 12 and sticks a flux 16 to the cushion 13b. The transfer roller 13 is moved to the vicinity of a chip 15 absorbed to a bonding tool 14, and the cushion 13b is moved horizontally, by bringing it into contact with a bump 15a of the chip 15. Thus, the flux 16 on the cushion 13b is transferred to the bump 15a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flip chip bonder for bonding a semiconductor chip having bumps formed thereon to a substrate, and more particularly to a flux transfer device for transferring flux to bumps and a method for transferring the same.

[0002]

2. Description of the Related Art FIG. 6 shows a conventional flux transfer device.

This flux transfer device includes a flux supply nozzle 11 for discharging a flux and a transfer stage 1 for storing the flux discharged from the supply nozzle 11.
2 are provided. The transfer stage 12 has a pair of squeegees 23 with two flux levels. The squeegee 23 has a groove 23a for adjusting the film thickness of the flux.
Is provided. Further, the bonding tool 14 has a semiconductor chip 15 to which the flux is to be transferred sucked down the bump 15a.

FIG. 7 shows a conventional flux transfer method.

As shown in FIG. 7, first, a flux 16 is discharged from a flux supply nozzle 11, and the flux 16 is stored on a transfer stage 12. Next, two squeegees 23 are simultaneously moved in parallel on the transfer stage 12. Thus, the thickness of the flux 16 is
The thickness corresponds to the depth of the third groove 23a. afterwards,
By lowering the bonding tool 14 having sucked the semiconductor chip 15 toward the transfer stage 12, the bump 15a of the semiconductor chip 15 is immersed in the flux 16, and the flux 16 is transferred to the bump 15a. One round trip of the squeegee 23 causes the flux 16 to be bump 1
5a.

[0006]

The flux 16 may be transferred to the tip of the bump 15a. For this reason, the film thickness of the flux 16 on the transfer stage 12 may be sufficiently thin corresponding to it. However, the height of the bumps 15a provided on the semiconductor chip 15 is not always uniform, and has a variation of about ten and several μm. Therefore, when the thickness of the flux 16 on the transfer stage 12 is small, the amount of the flux 16 transferred to the bump 15a may be extremely small or may not be transferred. As a result, the soldering may not be successful and open failures may occur frequently. In order to transfer a sufficient amount of flux 16 to all bumps 15a, the transfer stage 1
If the thickness of the flux 16 on the second layer 2 is increased, the flux 16 may be applied to the chip surface other than the bumps 15a. For this reason, when the flux 16 is washed, the washing may not be sufficiently performed, which may adversely affect the product.

The flux 1 on the transfer stage 12
Even when the film thickness of No. 6 is optimally adjusted, if the parallelism between the bonding tool 14 and the stage surface is not correct, an appropriate amount of flux 16 cannot be transferred to all the bumps 15a. Therefore, when the bonding tool 14 is replaced, the parallelism between the stage surface and the surface of the bonding tool 14 must be adjusted.

As described above, in the conventional transfer method, it is very difficult to transfer an appropriate amount of flux only to the bumps of the semiconductor chip. Therefore, there has been a problem that the quality of the product becomes unstable and the yield is lowered.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to make it possible to transfer an appropriate amount of flux only to bumps of a semiconductor chip, and to improve yield by stable solder bonding. An object of the present invention is to provide a flux transfer device and a transfer method that can be improved.

[0010]

The present invention uses the following means to achieve the above object.

A flux transfer device according to the present invention includes a flux supply unit for supplying a flux to a transfer stage, a roller-shaped transfer device on which the flux on the transfer stage is adhered to a surface, and a transfer device configured to transfer the transfer device to the transfer stage. And a driving unit that is driven in contact with the upper part and the surface of the bump part of the semiconductor chip.

The transfer unit has a concave portion on the surface.

The transfer unit is made of an elastic material.

According to the flux transfer method of the present invention, there are provided a step of supplying a flux to a transfer stage, a step of applying the flux on the transfer stage to a roller-shaped transfer device, and a step of applying the transfer device to a bump portion surface of a semiconductor chip. And transferring the flux to the bumps.

The transfer unit has a concave portion on the surface.

The transfer unit is made of a material whose surface has elasticity.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

First, the flux transfer device of the present invention will be described with reference to FIG.

In FIG. 1, a flux supply nozzle 11
Discharges flux. The transfer stage 12 stores the flux discharged from the supply nozzle 11. A transfer roller 13 is provided on the transfer stage 12. The transfer roller 13 is provided with a drive unit 19, which allows the transfer roller 13 to move in the longitudinal direction of the transfer stage 12 and in the direction orthogonal to the surface of the transfer stage 12. The transfer roller 13 is provided with a shaft portion 13a of the roller and a cushion portion 13b which covers the shaft portion 13a and has a concave portion on the surface.

FIG. 2 shows the transfer roller 13 specifically. On the surface of the cushion portion 13b, for example, a bump 1
The groove-shaped concave portions 17 are formed at intervals corresponding to the pitch of 5a. The depth of these recesses 17 is shallower than the height of the bumps 15a, so that the tips of the bumps 15a enter. The material of the cushion portion 13b is flux 16
What is necessary is just to have resistance with respect to, for example, a rubber material is applied.

On the bonding tool 14, a semiconductor chip 15 to which a flux 16 is transferred is bumped.
a is adsorbed downward.

Next, a method of transferring flux to bumps of a semiconductor chip will be described with reference to FIG.

As shown in FIG. 3, a flux 16 is discharged from a flux supply nozzle 11 and the flux 16 is discharged.
6 is stored on the transfer stage 12. Next, by moving the transfer roller 13 along the transfer stage 12, the flux 16 is moved to the cushion portion 1 of the transfer roller 13.
3b. At this time, the flux 16 has entered the recess 17 shown in FIG. The amount of the flux 16 in the concave portion 17 is an appropriate amount to be transferred to the bump. Next, the transfer roller 13 is connected to the bonding tool 1.
4, the transfer roller 13 is moved in the horizontal direction while contacting the surface of the bump 15a of the semiconductor chip 15 which is attracted to the bonding tool 14. As a result, an appropriate amount of the flux 16 in the concave portion 17 is removed from the bump 15a.
Is transferred to

According to the above embodiment, the transfer roller 13 having the surface on which the flux 16 is adhered moves while rotating in contact with the surface of the bump 15a, so that the flux 16 is transferred to each bump 15a. For this reason, it is not necessary to adjust the film thickness of the flux 16 on the transfer stage 12 unlike the related art.

Further, a bump 15 is formed on the surface of the transfer roller 13.
The tip of a can enter and an appropriate amount of flux 16
Is provided. Therefore, an appropriate amount of the flux 16 can be reliably transferred only to the bump 15a, and the possibility that the flux 16 adheres to a portion other than the bump 15a can be extremely reduced.

Since the cushion portion 13b is formed of a deformable material, the cushion portion 13b is deformed according to the shape of the other party. For this reason, as shown in FIG. 4A, when the height of the bumps 15a of the semiconductor chip 15 varies, as shown in FIG.
3 and the bonding tool 14 are not parallel, the height difference between the bumps 15a
Can be absorbed by the cushion portion 13b. Therefore, even in the case described above, as shown in FIG.
An appropriate amount of the flux 16 can be transferred only to the bump 15a.

As described above, since an appropriate amount of flux can be transferred only to the bump, stable solder bonding can be realized, and as a result, the quality of the product can be stabilized and the yield can be improved.

The present invention is not limited to the above embodiment.

In the above embodiment, the groove-shaped concave portion 17 is provided on the surface of the transfer roller 13, but may be a concave portion 18 having a shape as shown in FIG. The planar shape of the concave portion 18 is not limited to a rectangle, but may be a circular shape or the like. Also,
When the cushion portion 13b is formed of a material that sufficiently adheres the flux and is sufficiently deformed according to the bump 15a, the surface of the cushion portion 13b may not have a concave portion.

In addition, the present invention can be variously modified and implemented without departing from the gist thereof.

[0031]

As described above, according to the present invention, a flux transfer apparatus and a flux transfer apparatus capable of transferring an appropriate amount of flux only to bumps of a semiconductor chip and improving the yield by stable solder bonding are provided. A transfer method can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view of a flux transfer device according to the present invention.

FIG. 2 is a perspective view illustrating an example of a transfer roller of the present invention.

FIG. 3 is a schematic diagram showing the operation of the flux transfer device according to the present invention.

FIG. 4 is a side view showing a relationship between a transfer roller and a bump according to the present invention.

FIG. 5 is a perspective view showing another example of the transfer roller of the present invention.

FIG. 6 is a perspective view of a conventional flux transfer device.

FIG. 7 is a sectional view showing the operation of a conventional flux transfer device.

[Explanation of symbols]

 11: Flux supply nozzle, 12: Transfer stage, 13: Transfer roller, 13a: Shaft, 13b: Cushion, 14: Bonding tool, 15: Semiconductor chip, 15a: Bump, 16: Flux, 17: Recess, 18 ... Recess, 19 ... Drive section.

Claims (6)

[Claims] A flux supply unit for supplying a flux to a transfer stage; a roller-shaped transfer device on which the flux on the transfer stage is adhered to a surface; a bump on the transfer stage and a bump on a semiconductor chip; A flux transfer device comprising: a drive unit configured to drive in contact with a surface of the unit. 2. The flux transfer device according to claim 1, wherein the transfer device has a concave portion on a surface thereof. 3. The flux transfer device according to claim 1, wherein the surface of the transfer device is made of a material having elasticity. A step of supplying a flux to a transfer stage; a step of applying the flux on the transfer stage to a roller-shaped transfer device; and moving the transfer device in contact with a bump portion surface of a semiconductor chip; Transferring the flux to the bumps. 5. The flux transfer method according to claim 4, wherein the transfer device has a concave portion on a surface thereof. 6. The flux transfer method according to claim 4, wherein the surface of the transfer unit is made of a material having elasticity.