JP2976629B2 - Bump forming equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bump forming apparatus,
More specifically, the present invention relates to a structure of a bump forming apparatus capable of performing post-processing of a defective ball of a wire.

[0002]

2. Description of the Related Art It is known that bumps are formed on a chip by wire bonding means to produce a flip chip or the like. The wire bonding means forms a ball by approaching the torch to the lower end of the wire derived from the capillary tool, and then presses and bonds the ball to the electrode of the chip on the chip stage by the lower end of the capillary tool, Next, the wire is clamped by a clamper, and the wire is pulled up, so that the wire is cut from the joint between the ball and the wire to form a bump.

[0003]

By the way, when the wire is pulled up, the bonded ball may peel off from the electrode due to, for example, contamination of the electrode of the chip, and a bump may not be formed. In this case, a ball remains at the lower end of the wire, but this ball 3 is a defective ball deformed flat because it was once pressed against the electrode. If this defective ball is not removed, it may hinder the next bump formation. Become. Conventionally, the defective ball is thrown away on an unnecessary electrode of the chip, or an operator pulls out the wire from the capillary tool with tweezers and manually removes the wire, and then resumes the bump forming operation.

However, the chip does not always have an unnecessary empty electrode, and in this case, the defective ball cannot be discarded on the empty electrode. Since the ball is not constant, the distance from the torch to the lower end of the wire is not constant during the formation of the ball, and the size of the newly formed ball varies.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a bump forming apparatus capable of improving post-processing of a defective ball of a wire.

[0006]

According to the present invention, the capillary tool held at the tip of the horn is raised and lowered by the vertical movement of the horn, and is formed at the lower end of the wire led out from the capillary tool. In a bump forming apparatus that forms a bump on the electrode by bonding a ball to an electrode of a chip on a chip stage and cutting the wire, a defective ball is thrown away on the side of the chip stage. A discarding stage is provided.

[0007]

In the above structure, a bump formation error causes
When a defective ball is formed, the capillary tool is moved onto the discarding stage, and the tool is moved up and down to discard the defective ball onto the discarding stage, and then the capillary tool is placed on the chip stage. Return to form bumps again.

[0008]

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a bump forming apparatus. 1
Is a horn of the bonding device 9, and the horn 1
The capillary tool 2 is held at the tip of the. A wire 3 is inserted through the capillary tool 2,
At its lower end, a ball 3a formed by electric spark with a torch (not shown) is formed. 20 is X
The Y table 21 is a drive unit of the horn 1. When the drive unit 21 is driven, the horn 1 moves up and down, and the capillary tool 2 held at the tip of the horn 1 moves up and down.

Reference numeral 4 denotes a platform disposed below the bonding apparatus, and a chip stage 5 is provided on the platform 4. Numeral 6 denotes a discarding stage for discarding and hitting the defective ball 3a ', which is provided integrally on the side of the chip stage 5. In FIG. 2, reference numeral 7 denotes a suction passage provided from the base portion 4 to both stages 5 and 6, and the suction port 7 of the chip stage 5 and the discarding stage 6.
a, 7b. P is a chip having an electrode 10 formed on the upper surface, and is sucked on the chip stage 5 by the vacuum pressure of the suction port 7a. Numeral 8 denotes a dummy chip for dumping, which is sucked on the dumping stage 6 by the vacuum pressure of the suction path 7. The dummy chip 8 of this embodiment is a silicon chip, and its surface has
In order to facilitate bonding of the defective ball 3a ', a material having good adhesion to the defective ball 3a', such as aluminum, is deposited. Further, the thickness L1 of the dummy chip 8 is set to be equal to the thickness L1 of the chip P so that it is not necessary to adjust the vertical stroke of the capillary tool 2 when throwing away.
2, the upper surface of the chip P and the upper surface of the dummy chip 8 are at the same level.

The present apparatus has the above-described configuration, and the operation will be described next. As shown in FIG.
0 is moved in the X and Y directions, the capillary tool 2 is moved above the chip P, and the drive unit 21 is driven to move the horn 1 up and down. The ball 3a formed at the lower end of the wire 3 is bonded to the electrode 10 of the chip P, then the capillary tool 2 is raised, then the wire 3 is clamped by a clamper (not shown), and the wire 3 is pulled up while being clamped. The bumps 3a are formed on the electrodes 10 by cutting.

In FIG. 2, reference numeral 3a 'denotes a flat defective ball generated at the lower end of the wire 3 due to the formation error of the bump 3a as described above. When the defective ball 3a 'is formed, the XY table 20 is driven to move the capillary tool 2 onto the discarding stage 6, and the tool 2 is raised and lowered in the same manner as in normal bump formation. 3a 'is thrown away on the dummy chip 8 and hit. As described above, according to the present means, the defective ball 3a 'can be easily discarded and discarded without the need for unnecessary empty electrodes on the chip P or the troublesome work of the operator pulling out the wire with tweezers. . In addition, since the discarding is performed by the same method as the normal bump formation, as described above, when the ball 3a is formed again, the lead-out length of the wire 3 from the capillary tool 2, that is, a torch (not shown) And the distance from the lower end of the wire to the lower end of the wire can be made constant.
a can be formed. When the disposal of the defective ball 3a 'is completed as described above, the XY table 20 is moved, the capillary tool 2 is returned onto the chip stage 5, and the operation of forming the bump 3a is restarted.

[0013]

As described above, according to the present invention, the capillary tool held at the tip of the horn is raised and lowered by the vertical movement of the horn, and is formed at the lower end of the wire led out from the capillary tool. In a bump forming apparatus that forms a bump on the electrode by bonding the ball to the chip electrode on the chip stage and cutting the wire, the defective ball is thrown away on the side of the chip stage. Since the discarding stage is provided, the post-processing of the defective ball of the wire can be improved.

[Brief description of the drawings]

FIG. 1 is a perspective view of a bump forming apparatus according to the present invention.

FIG. 2 is a sectional view of the same.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horn 2 Capillary tool 3 Wire 3a Ball (bump) 3a 'Defective ball 5 Chip stage 6 Discarding stage 10 Electrode P chip

Claims (1)

(57) [Claims] 1. A vertical movement of a horn raises and lowers a capillary tool held at a tip of the horn, and a ball formed at a lower end of a wire led out from the capillary tool is moved to a chip on a chip stage. In a bump forming apparatus that forms a bump on the electrode by bonding to the electrode and cutting the wire,
A bump forming apparatus, further comprising a discarding stage for discarding a defective ball on a side portion of the chip stage.