JPH0357231A - Wire bonding apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a wire bonding device.

[Conventional technology]

As a conventional technique, for example, Japanese Patent Publication No. 64-10093
There is a wire bonding device described in the publication. A conventional wire bonding device includes a swinging arm that swings freely around a support shaft installed in a frame, a cavity attached to the tip of the swinging arm, and a drive motor that swings the swinging arm. and a position detector that detects the displacement of the slow moving arm and the velocity by differentially converting this displacement. A conventional wire bonding device will be described in detail with reference to the drawings.

FIG. 2 is a side view showing a conventional example.

The wire bonding device shown in FIG.
01 is capable of swinging around a shaft 102 as shown by arrow B, and a cavity 1o3 is attached to one end thereof, and a moving coil 104 is attached to the other end. The moving coil 104 is located within a gap in a magnetic circuit 105 composed of a permanent magnet and a yoke (not shown), and by passing a current through the moving coil 104, the arm 1 is moved.
Drive 01.

A bracket 108 is fixed to the moving coil 104, and a contact point 105 that can move forward and backward in the axial direction of a position detector 106 fixed to a frame 109 is in contact with the tip of the bracket 108. The position detector 106 is connected to a differential circuit (not shown), and the speed can be determined from the output thereof. However, when a current is applied to the moving coil 104,
The swinging arm lot swings about the shaft 102, and in accordance with the movement, the cavity 103 attached to the swinging arm 101 also moves up and down. At this time, the bracket 108 moves up and down as the swing arm 101 swings, and its stroke is detected by the position detector 106.

As a result, the position detector 106 detects the position of the cavity 103, and also detects the speed by converting its output using a differentiating circuit. Generally, in a wire bonding device, when the cabillary comes into contact with the electrode pad or lead frame of an IC, the stability and quality of the bonding is greatly affected by moving the capillary at a low speed so as not to collide with them.

[Problem to be solved by the invention]

The above-mentioned conventional wire bonding equipment measures the speed by differentially converting the position signal of the capillary, so it is not possible to measure the speed accurately when the position of the capillary does not change much, that is, when the capillary is moving at a low speed. is not possible. For this reason, when the cabillary comes into contact with the IC's electrode pad or lead frame, it cannot be moved accurately and at low speed, which tends to cause cracks and adhesion under the pad, resulting in unstable bonding and poor quality. Since bondability was low, there was a drawback that productivity deteriorated.

[Means to solve the problem]

The wire bonding apparatus of the present invention includes: (A) a drive motor that swings the swing arm; (B) current detection means that detects the current flowing through the drive motor; (C) detects the amount of swing of the swing arm. position detection means; (D) speed detection for detecting the swinging speed of the swinging arm based on the amount of current flowing through the drive motor, the voltage applied to the drive motor, and the swinging amount of the swinging arm; It consists of means, and.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention.

The wire bonding apparatus shown in FIG. Position detector 1 that detects the amount of swing
0, (D) speed detection means for detecting the swinging speed of the swinging arm 1 based on the amount of current flowing through the moving coil 4, the voltage applied to the moving coil 4, and the swinging amount of the swinging arm l; It consists of: The swinging arm 1 can swing around a swinging shaft 2 in the direction of an arrow A, and a cavity 3 is attached to one end of the swinging arm 1, and a moving coil 4 is attached to the other end. The moving coil 4 is located within a gap in a magnetic circuit 5 made up of a permanent magnet and a yoke, and constitutes a swing motor, and drives the arm 1 by passing a current through the moving coil 4.

The cavity 3 holds the gold wire 8 and presses the tip of the gold wire 8 against the bonding pad of the pellet 9 for bonding. Furthermore, a position detector 10 is mounted on the swing axis 2 of the swing arm (■).
is attached to detect the amount of swing of the swing arm 1.

Furthermore, the current flowing through the moving coil 4 is detected by a current detector 20, which is connected to a speed detector 30.

Next, a speed detection method will be explained.

A system consisting of a swinging arm 1 and a swinging motor 6 has a voltage applied to the swinging motor 6 as an input, and the swinging amount of the swinging arm and the current flowing through the moving coil 4 as outputs.
This system is observable if it is considered as a control system with the amount of swing, swing speed, and current as state variables. Therefore, for this system, the voltage (input) applied to the swing motor 6, the swing amount of the swing arm 1, and the moving coil 4
By configuring an observer that estimates the state quantity based on the current flowing through the oscillating arm 1 and the output current flowing through the oscillating arm 1, the oscillating speed of the oscillating arm 1 can be determined. At this time, since not only the amount of oscillation but also the current is treated as an output, accurate state estimation is possible even when there are small changes in the amount of oscillation, that is, when the oscillation speed is slow. By controlling the voltage applied to the moving coil 4 using the swing angle signal and the swing angular speed signal, the displacement of the cavity and the bonding speed can be set arbitrarily.

〔Effect of the invention〕

The wire bonding device of the present invention determines the speed not only from the amount of movement of the swinging arm but also from the motor current and applied voltage, so it is possible to accurately measure the speed of the cavity not only during high-speed operation but also during low-speed operation. As a result, the cavity can be moved with high precision and at low speed, making it possible to perform stable and high-quality bonding, which has the effect of improving bonding productivity.

[Brief explanation of drawings]

Fig. 1 is a block diagram showing an embodiment of the present invention, and Fig. 2 is a measurement diagram showing a conventional example. ■... Swing arm, 2... Axis, 3...-cabinary,
4...Moving coil, 5...Magnetic circuit, 8...One gold wire, 9...Bellet,
10... Position detector, 20... Current detector, 30... Speed detector.

Claims (1)

[Claims] (A) A drive motor that swings the swing arm, (B) Current detection means that detects the current flowing through the drive motor, (C) Position detection that detects the amount of swing of the swing arm. (D) speed detection means for detecting the swinging speed of the swinging arm based on the amount of current flowing through the drive motor, the voltage applied to the drive motor, and the swinging amount of the swinging arm; A wire bonding device comprising: