JPS6229896B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a capillary vertical movement mechanism for vertically moving a capillary in a wire bonding apparatus.

Conventionally, as such a capillary vertical movement mechanism, those shown in Japanese Patent Application Laid-Open Nos. 54-154273 and 55-24403 are known. In this structure, the bonding arm holding the capillary is rotatably held by a vertically moving block, and this vertically moving block is screwed into a male threaded block rotated by a motor and moved up and down by a female threaded block that moves up and down. It's designed to slide. In this way, in order to move the bonding arm up and down, the rotation of the motor, which is the drive unit, must be changed to the up and down movement of the female thread block, which puts a load on the motor and makes it impossible to move the bonding arm quickly. . Furthermore, the vertical movement mechanism of the female screw block is complicated, resulting in high cost, and also has the disadvantage that assembly and adjustment takes time.

The purpose of the present invention is to eliminate the drawbacks of the above-mentioned prior art,
It is an object of the present invention to provide a capillary vertical movement mechanism that can reduce the load on a motor, increase the speed of capillary vertical movement, and has a simple mechanism.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 1 is a partially sectional side view showing an embodiment of a capillary vertical movement mechanism according to the present invention, and FIG. 2 is a sectional view taken along the line 2--2 in FIG. Capillary 10 at one end
The bonding arm 11 holding the bonding arm 11 is fixed to a support shaft 15 rotatably attached via a bearing 14 to a head frame 13 fixed to an XY feeder 12 that moves in the XY direction. A cylindrical portion 13a concentric with the support shaft 15 projects inward from the head frame 13, and a drive block 17 is rotatably mounted via a bearing 16.
An insulating block 19 holding a contact rod 18 is fixed to the drive block 17, and the bonding arm 11 is connected to the hook 20 of the support shaft 15 and the drive block 1.
It is urged counterclockwise by a spring 22 hooked on the hook 21 of No. 7 to contact the contact rod 18.
Further, a clamp arm 24 holding a clamper 23 is fixed to the drive block 17.

A motor 31 equipped with a rotary encoder 30 is fixed to the side plate of the head frame 13.
The drive shaft 31a of the motor 31 has an eccentric shaft 33 having an eccentricity e with a bearing 32 attached to the tip.
is fixed. The bearing 32 is held between two connecting pins 35 and 36 fixed to a drive arm 34 fixed to the drive block 17.

Further, a spool lever 40 is attached to the head frame 13.
is fixed, and a spool 42 around which a wire 41 is wound is attached to the end of the spool lever 40. The wire 41 wound around the spool 42 is inserted into the capillary 10 through the guide pipe 43 and the clamper 23. Further, the lead frame 51 with the pellets 50 attached thereto is guided and transported by a frame feeder 52.

Next, the operation of this mechanism having such a configuration will be explained. FIG. 1 shows the moment when the capillary 10 hits the bonding surface, but before the wire is connected, the capillary 10 is above the bonding surface, and the tip of the wire 41 protrudes from the tip of the capillary 10. Therefore, when the head frame 13 is moved on a plane by the XY feeder 12 and the capillary 10 is positioned above the first bond point, the motor 31 is rotated. The rotation of the motor 31 causes the bearing 32 attached to the eccentric shaft 33 to move upward by an amount of eccentricity e. As a result, the drive block 17
rotates in the direction of arrow A around the cylindrical portion 13a of the head frame 13 via the connecting pins 35, 36 and the drive arm 34, and the clamper 23 attached to the contact rod 18 and the clamp arm 24 descends.
When the contact rod 18 is lowered, the bonding arm 11 is rotated in the direction A about the support shaft 15 while being in pressure contact with the contact rod 18 due to the biasing force of the spring 22, and the capillary 10 is lowered. Then, as shown in FIG. 1, the moment the capillary 10 hits the bonding surface, the contact rod 18 is slightly separated from the bonding arm 11, and as a result, the bonding arm 11
Since the contact rod 18 is no longer electrically conductive, the height of the bonding surface is detected. From this state, the motor 31 rotates slightly and then stops. Then, the wire 41 is bonded to the first bonding point using the capillary 10.

After the first bonding is completed, the motor 31 rotates in the opposite direction to the above, and the capillary 10 is raised by the reverse operation. This amount of increase is determined by the distance (wire length) to the second point. Subsequently, in the same manner as described above, the capillary 10 is moved in a plane by the XY feeder 12 and positioned above the second bonding point. Next, the motor 31 rotates, and the capillary 10 descends and presses into contact with the second bonding point, completing the wire connection work. Then, when moving on to the next connection operation, the capillary 10 rises, but at this time the clamper 23 closes and cuts the wire 41. Here, the vertical amounts of the capillary 10 and the clamper 23, ie, the amount of rotation of the motor 31, are measured and controlled by the rotary encoder 30.

In this way, the drive arm 34 that moves the bonding arm 11 up and down is driven by the eccentric shaft 33, which is rotated by the motor 31. Since the mechanism is simple, the cost of the device can be reduced, and assembly and adjustment can be facilitated. Further, since there is no need to turn a screw as in the conventional case, the load on the motor 31 is reduced, the vertical movement speed of the capillary 10 can be increased, and wire bonding can be performed at high speed.

Note that the drive block 17 may be provided on the head frame 13 so as to be vertically movable.

As is clear from the above description, according to the capillary vertical movement mechanism of the present invention, the mechanism is simple and costs can be reduced, and assembly and adjustment can be facilitated. In addition, the load on the motor is small and wire bonding can be performed at high speed.

[Brief explanation of the drawing]

FIG. 1 is a partially sectional side view showing an embodiment of a capillary vertical movement mechanism according to the present invention, and FIG. 2 is a sectional view taken along the line 2--2 in FIG. 10... Capillary, 11... Bonding arm, 13... Head frame, 15... Support shaft, 17...
... Drive block, 18 ... Contact rod, 19 ... Insulation block, 30 ... Motor, 33 ... Eccentric shaft, 3
4... Drive arm, 41... Wire.

Claims (1)

[Claims] 1. A motor fixed to a head frame capable of plane movement in the XY directions, an eccentric shaft rotationally driven by the motor, and a capillary with a wire inserted therein, which is swingably mounted on the head frame. a bonding arm, and a drive member that extends on the surface of the bonding arm so as to prevent the bonding arm from descending, is supported by the head frame so as to be swingable or vertically movable, and is swingable or vertically movable about the eccentric shaft. A capillary vertical movement mechanism consisting of.