JPS58182844A - Supersonic bonder - Google Patents

Abstract

PURPOSE:To accurately enable stable bonding by mounting a mechanism for elevationally moving a wire clamp, then upwardly moving a wire clamp at the second bonding time, thereby avoiding the wire to contact the sealing of a case. CONSTITUTION:A wire 6 which reaches the end of a wedge 2 through a long hole of a bonding arm (supersonic vibrator) 1 is mounted on a wire clamp 3. The operation of a wire clamp 3 is performed via an arm 9 by a motor 8, and positioning is performed via an encoder 12 mounted on a rotational shaft of the motor 8. With this structure, the moving locus of the clamp 3 becomes circular. Thus, the wire distance from the end 2 of the wedge to the wire clamp 3 is maintained constantly, thereby facilitating setting.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an ultrasonic bonder, and is particularly useful in the process of assembling integrated circuit elements (IC), in which the pad electrodes of semiconductor pellets and leads are connected using metal wires of about 30 μm in diameter. This invention relates to an ultrasonic bonder that performs bonding entirely by ultrasonic vibration.

In conventional ultrasonic bonders, the angle of the wire with respect to the semiconductor pellet surface (wire angle) is constant, generally 30°, 45°, or 60°. This wire angle comes into play when bonding ceramic cases and the like. If the wire angle is small, after the first bond to the semiconductor pellet, the wire will hit the edge of the seal ring when making the second bond to the lead side of the case, causing the wire to bend, scratch, or break. Bonding work becomes impossible. To prevent this,
If the wire angle is increased, the gap between the tip of the wire and the tip of the bonding tool (wedge) becomes too wide during wire feeding, resulting in a disadvantage that bonding accuracy (position & accuracy, bonding shape, etc.) becomes extremely poor.

An object of the present invention is to install a mechanism for moving the wire clamp up and down, so that the wire clamp can be moved upward during the second bonding to avoid the wire from coming into contact with the seal ring of the case. During feeding, the wire clamp is moved downward to bring the wire tip and the wedge tip into close contact with each other, thereby achieving highly accurate and stable bonding.

The feature of the present invention is that the entire wire is clamped between an ultrasonic sensor having a long gap as a wire path and a bonding tool (wedge) fixed to the tip of the ultrasonic sensor, and the wire is fed out and torn C'. This ultrasonic bonder is equipped with a mechanism in which the wire clamp moves vertically during bonding to change the angle of the wire relative to the semiconductor pellet surface (wire angle).

Next, an embodiment of the present invention will be explained using all the drawings.

In Figure 1, the bonding arm (ultrasonic transducer)
Wire 6 that passes through the elongated hole of 1 and reaches the tip of wedge 2
, the rear end V of the wire clamp 3 clamped between
? - Attach an L-shaped arm 4, and attach the coil 10 of the IJ near motor 7 to the other end of this L-shaped arm 4. With such a structure, the current flowing through the coil 10 can be completely varied and the wire clamp 3 can be directly moved by moving the coil 1 (1), thereby making the wire angle variable.

Further, the positioning of the wire clamp 3 can be easily controlled by detecting the entire output voltage of the magnet sensor 11.

FIG. 2 shows another embodiment. In FIG. 2, all movements of the wire clamp 3 are performed by a motor 8 via an arm 9, and positioning is performed by an encoder 12 attached to the rotating shaft of the motor 8.

With this structure, the movement locus of the wire clamp 3 becomes a circle, so the wire clamp 3 moves from the wedge tip 2 to the wire clamp 3.
Since the wire distance between the

As explained above, the present invention has a sound effect that makes bonding of ceramic cases, etc., which was difficult in the past, easier by moving the wire clamp in the entire vertical direction during bonding.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are diagrams showing this embodiment. In addition, in 4, 1... Ultrasonic sensor, 2... Wedge,
3...Wire clamp, 4...L-shaped arm, 5...Wire guide, 6...
...Wire, 7...Linear motor, 8...
... Motor, 9 ... U-shaped arm, 10.
... Coil, 11 ... Magnet sensor, 12 ... Encoder. 5-

Claims (1)

[Claims] The entire wire is clamped between an ultrasonic vibrator with a long hole as a wire path and a bonding tool fixed at its tip, and the wire clamp that performs all of the wire feeding and tearing moves vertically during bonding. An ultrasonic bonder characterized by completely eliminating the mechanism for changing the angle of the wire with respect to the semiconductor pellet surface.