JPS5824017B2 - Reversing device in chip bonder - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reversing device in a chip bonder that directly bonds chips to the circuit surface of a substrate in order to manufacture semiconductor devices.

Recently, with the development of electronic products, in order to further reduce costs, chips are being bonded directly to the circuit surface of the substrate for watches, calculators, thick film ICs, etc.

In this case, as shown in FIG.
The circuit board 1a is stored in the storage tray 2 with the circuit surface 1a facing upward to avoid scratches, dirt, etc.

As shown in FIG. 2, when bonding the bumps 1b of the chip 1 to the pads 3b on the circuit surface 3a of the substrate 3, the circuit surface 3a of the substrate 3 faces upward, and the circuit surface 1a of the chip 1 faces downward. It will be held in

In this way, the chip 1 is stored in the storage tray 2 with the circuit surface 1a facing upward, and when bonding to the substrate 3, the circuit surface 1a is facing downward, so the chip 1 is transported from the storage tray 2 to the bonding position. It is necessary to reverse the suction arm axis (not shown) for suction.

Conventionally, the axis of the suction arm that suctions the chip is reversed by reciprocating a motor at a constant angle.

However, in order to rotate the motor forward and backward, a specific motor such as a lever signal motor or a DC motor must be used, and the control circuit is complicated to detect constant angle rotation and ensure accuracy in stopping the motor. It had the disadvantage of being expensive.

Another method is to combine a rack and pinion, connect the suction arm shaft to the pinion shaft, and move the rack back and forth linearly using an air cylinder, solenoid, etc., thereby causing the suction arm shaft to reciprocate in forward and reverse directions. However, this method also has the disadvantage of being mechanically complicated.

The present invention was made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a reversing device for a chip bonder that has a simple structure and can reduce costs.

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

FIG. 3 is a schematic perspective view showing one embodiment of the present invention.

10 is a frame housing a reversing mechanism (described later) for the suction arm shaft 11; 12 is a suction nozzle provided at the tip of the suction arm shaft 11;
adsorbs.

Reference numeral 14 denotes a unidirectional rotating motor that drives the suction arm shaft 11, and is fixed to the frame 10.

Reference numeral 15 denotes a working tool for picking up the chip 1 from the suction nozzle 12 and transporting it to a bonding position or a chip position correction station, and the tool 15 is designed to be positioned above the suction nozzle 12 when the suction arm shaft 11 is reversed as shown by the chain line. It's summery.

Note that the storage tray 2 that stores the chips 1 is the suction nozzle 1.
When the chip 3 is removed by the suction nozzle 12, the next chip 3 is held on a moving table (not shown) so as to be directly below the suction nozzle 12.

4 and 5 show the reversal mechanism of the suction arm shaft 11,
Figure 4 is a sectional view taken along the line A-A in Figure 3, and Figure 5 is a cross-sectional view taken along line B in Figure 3.
-B sectional view.

20 is a cam fixed to the output shaft 21 of the motor 14 with a screw 22 and rotates in one direction; 23 is a swinging lever rotatably supported on a fulcrum shaft 24 held at both ends by the frame 10; A cam follower 25 provided on the lever 23 is urged by a spring 26 so as to come into pressure contact with the cam 20.

27 is a fan-shaped gear fixed with a screw 29 to a shaft 28 rotatably held at both ends in the frame 10; 30 is a connecting rod connecting the swinging lever 23 and the gear 27; The uniballs 31 and 32 are screwed together, one uniball 31 is rotatably connected to the upper end of the swing lever 23 with a bolt 33, and the other uniball 32 is rotatably connected to the center of the plane of the gear 2T with a bolt 34. freely connected.

A stopper 35 is screwed onto the frame 10 so as to come into contact with one end surface of the gear 27, and a pinion 36 is fixed to the suction arm shaft 11 with a screw 37, which meshes with the gear 27.

Next, the operation of the device constructed as above will be explained.

When the suction nozzle 12 is at position C on the chip 1 shown in FIG. 3, the vacuum circuit is opened under control (not shown) and the chip 1 is suctioned.
The suction is performed at the stop portion 20a of the cam 20 shown in FIG. 4, which has the smallest diameter.

When the cam 20 rotates in the D direction and reaches the upward curve 20b, the swing lever 23 rotates clockwise, and the gear 27 rotates in the same direction via the connecting rod 30.

As a result, the pinion 36 rotates in the counterclockwise direction E, and the suction arm 11 fixed to the pinion 36 also rotates as shown in FIG.
When the suction nozzle 12 rotates in the E direction as shown by the dotted chain line and reaches the stop curve 20C of the maximum diameter of the cam 20, the suction nozzle 12 is located at the F position.

When the work tool 15 is lowered onto the suction nozzle 12 by a drive mechanism (not shown) at the stop curve 20c of the cam 20,
The vacuum of the suction nozzle 12 is cut off by timing control (not shown), and the vacuum is passed to the working tool 15, so that the working tool 15 suctions the chip 1 through the suction nozzle 12, and the working tool 15 moves upward.

Subsequently, when the cam 20 reaches the downward curve 20d, the swinging arm 23 starts rotating counterclockwise by the urging force of the spring 26, and when the cam 20 reaches the stop curve 20a, the suction nozzle 12
rotates in the opposite direction to the above and returns to the original C position.

Thereafter, the above operation is repeated to sequentially invert and feed the chips 1.

The final rotational position of the suction nozzle 12 at position C can be adjusted by moving the stopper 35 back and forth and adjusting the position where it contacts the gear 27.

In addition, the final rotation position at the F position can be adjusted using the connecting rod 30.
This can be done by changing the amount of screwing in by screwing both ends of the uni-ball 31 and 32 into the uniballs 31 and 32, one end with a right-hand thread and the other end with a left-hand thread.

Further, the suction arm 11 is not limited to being reversed by 180 degrees, but may also be rotated by an arbitrary angle θ.

In FIG. 4, the pitch radius of the pinion 36 is R1, the pitch radius of the gear 27 is R2, the length from the shaft 28 to the bolt 34 is R3, the rotation angle of the gear 2T is α, the bolts 33, 3
4, the distance from the fulcrum shaft 24 to the cam follower 25 in the swing lever 23 is l, the length up to the bolt 34 is L, the minimum radius of the cam 20 is rl, and the maximum radius is r2, then the following equation holds true.

Therefore, by determining each dimension in such a relationship, the suction arm shaft 11 can be easily designed to have an arbitrary angle θ.

Note that in the above formula, α and θ are expressed in radians.

In the above embodiment, the motor 14 was continuously rotated and the chip 1 was transferred at the stop portions 20a and 20c of the cam 20, but as shown in FIG.
A detection plate 40 may be attached to the detection plate 40, and the detection position of this detection plate 40 may be detected by the detector 41, and the motor 14 may be stopped every rotation and restarted with another start signal. A plurality of plates and detectors may be provided, and the motor may be stopped at each work position.

As is clear from the above description, according to the present invention, a cam is driven by one-way rotation of a motor, a swinging lever is swung by this cam, and a gear is connected to a gear via a connecting rod connected to this swinging lever. Since it has a simple structure in which the mechanism is reciprocally rotated and the chip is thereby reversed, an inexpensive reversing device for a chip bonder can be obtained.

[Brief explanation of the drawings] Figure 1 is a perspective view of the chip stored in the storage tray, Figure 2 is a perspective view for explaining the state before bonding the chip to the substrate, and Figure 3 is the book. A schematic perspective view showing an embodiment of the device according to the invention, FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3, FIG. 5 is a cross-sectional view taken along line B-B in FIG. 3, and FIG. 6 is a cam portion. FIG. 3 is a sectional view showing another embodiment of the invention. 1... Chip, 11... Suction arm shaft, 12... Suction nozzle, 14... Motor, 20... Cam, 23... ... Swinging lever, 27 ... Gear, 30 ... Connecting rod,
36...Pinion.

Claims (1)

[Claims] 1 A cam driven by a motor that rotates in one direction, a swinging lever that is reciprocated by this cam, a gear connected to this swinging lever with a connecting rod, a pinion that meshes with this gear, and this pinion. A reversing device for a chip bonder, characterized in that the suction arm shaft is fixed to the central axis of the chip bonder and is provided with a suction nozzle at one end for adsorbing chips, and the suction arm shaft is reversed by rotating a motor in one direction. .