JPH0529370A - Wire bonding equipment - Google Patents

Abstract

(57) [Summary] (Correction) [Configuration] The first coil 41 and the second coil 41 are detecting output signals from the position detector 6 and the velocity detector 7 until the capillary reaches a predetermined distance from the bonding pad. Coil 4
A current is applied to 2 to move the oscillating arm according to a predetermined profile, and after the capillary reaches a predetermined distance, the first coil 41 and the second coil 42 are arranged so that the oscillating arm approaches the bonding pad at a constant speed. Current is applied to the second coil 42 so that the swing arm approaches the bonding pad at a constant speed, and after the output signal from the speed detector 7 becomes zero, the second coil 42 is applied. A constant current is applied to control the current of the moving coil 4. [Effect] When the capillary comes into contact with the pellet, only the pressure coil is used and no excessive force is applied to the pellet.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding apparatus in a semiconductor device assembling process.

[0002]

2. Description of the Related Art A conventional wire bonding apparatus of this type
Are disclosed, for example, in Japanese Patent Application Laid-Open No. 2-98149 (Japanese Patent Application No. 63-25 / 1988).
1325). This conventional wire
The binding device is at least as shown in FIGS.
Moving coil 4 with two coils and key at one end
It has a capillary 3 and has a permanent magnet 51 and a yoke 52 at the other end.
Can swing in a plane perpendicular to the magnetic flux in the air gap of the magnetic circuit
The moving coil 4 is installed on the and swings in cooperation with the magnetic circuit.
Swing arm 1 that constitutes a mold motor, and swing of the swing arm 1
The position detecting means 6 for detecting the movement angle and the swing of the swing arm 1
And a speed detecting means 7 for detecting a moving speed.
In the wire bonding device, the capillary 3 is a semiconductor pellet.
Reach a predetermined distance from the bonding pad of
Are output signals from the position detecting means 6 and the speed detecting means 7.
Current is applied to the first and second coils while detecting
Move the swinging arm 1 according to the predetermined profile,
After the capillary 3 reaches a predetermined distance, the swing arm is
Second coil so that it approaches the bonding pad at a constant speed
Current is applied to the capillary 3 and the capillary 3
The output signal from the speed detection means 7 becomes zero.
After that, a constant current is applied to the second coil to move the coil.
It is configured to include means for controlling the current of the rule 4.

In this conventional wire bonding apparatus, an oscillating arm 1 can oscillate around an axis 2 as shown by an arrow in the figure. One end of the oscillating arm 1 is a capillary 3 and the other end is a moving coil 4. Has a structure attached. The moving coil 4 is a main coil 4 as shown in FIG.
1 and a pressure coil 42. Main coil 4
The number of turns of 1 is 20 times the number of turns of the pressure coil. The moving coils 4 are present in the air gap of the magnetic circuit 5 composed of the permanent magnet 51 and the yoke 52,
The arm 1 is driven by forming a swing motor which is a so-called short coil type VCM (voice coil motor) and supplying an electric current to the main coil 41 and the pressure coil 42. The position and speed of the arm 1 are detected by a position detector 6 and a speed detector 7 attached to the shaft 2, respectively.
The capillary 3 holds the gold wire 8 and presses the tip of the gold wire 8 against the bonding pad of the semiconductor pellet 9 for bonding.

Next, the operation of the conventional bonding apparatus is shown in FIG.
This will be described with reference to the diagram showing the configuration of the control system. The speed command circuit 110 compares the speed command signals according to a profile set so that the capillary 3 can move in a short time in advance until the capillary 3 descends from above the pellet 9 to a predetermined height (search height) from the pellet 9. The difference signal output to the circuit 111 and output from the comparison circuit 111 is selected by the switching circuit 13 and both the main coil 41 and the pressurizing coil 42 of the moving coil 4 are driven via the drive circuit 14, and the capillary 3 is changed into a profile. Therefore it works. When the capillary 3 reaches the search height, the speed command circuit 110 outputs a low constant speed (search speed).
A signal is output, and a coil switching signal is output to the drive circuit 1
Send to 4. The drive circuit 14 cuts off the current applied to the main coil 41 of the moving coil 4 and applies the current only to the pressurizing coil 42 to drive the capillary 3 at a low search speed and lower it until it contacts the pellet 9.

When the capillary 3 comes into contact with the pellet and the output of the speed detector 7 becomes zero, the switching circuit 13 selects a signal from the pressure command circuit 12 and applies a constant current to the pressurizing coil 42 so that the pellet 9 can be bonded to a certain level. Apply pressure.

The pressing coil 42 has a thrust constant of the main coil 41.
Since it is only 1/20 compared with the above, it is possible to finely adjust the force generated by providing a current limiter on the pressure coil 43. Since the search speed is generally very low, it is insensitive to judge whether or not the capillary 3 has come into contact with the pellet. It does not apply any force. On the other hand, when the capillary 3 reaches the search height, the moving speed of the capillary 3 and the search speed are significantly different. Therefore, in order to settle the moving speed of the capillary 3 to the search speed in a short time, it is necessary to generate a large thrust on the moving coil 4, but the pressure coil 42 cannot generate a large thrust (a large thrust is generated). If this is possible, it will not be possible to finely adjust the generated force), and it will take a long time for the moving speed of the capillary 3 to settle to the search speed.

[0007]

In the above-mentioned conventional wire bonding apparatus, since the pressurizing coil having a small thrust is used to set the search speed, the moving speed of the capillary is set to the search speed. Since it takes a long time, the bonding time is long and the productivity of bonding is poor.

[0008]

A wire bonding apparatus according to the present invention includes a moving coil having at least two coils, a capillary at one end and a permanent magnet and a yoke at the other end. A swing arm that is swingable in a plane perpendicular to the magnetic flux and cooperates with the magnetic circuit to form a swing motor, and a position detector that detects the swing angle of the swing arm. And a speed detecting means for detecting the swing speed of the swing arm, the position detecting means until the capillary reaches a predetermined distance from a bonding pad of a semiconductor pellet. While detecting the output signal from the speed detecting means, a current is applied to the first coil and the second coil to apply the swinging arm according to a predetermined profile. And a current is applied to the first coil and the second coil so that the swing arm approaches the bonding pad at a constant speed after the capillary reaches the predetermined distance. Is set to a constant speed, a current is applied only to the second coil so that the swing arm approaches the bonding pad at a constant speed, the capillary comes into contact with the bonding pad, and After the output signal becomes zero, it comprises a means for applying a constant current to the second coil to control the current of the moving coil.

[0009]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing the structure of a control system of an embodiment of the present invention, FIG. 2 is a perspective view showing the mechanism of a wire bonding apparatus of an embodiment of the present invention, and FIG. It is an enlarged view showing a portion of a dynamic motor 15. In the wire bonding apparatus shown in FIG. 2, the swing arm 1 is swingable around the shaft 2 as shown by the arrow in the figure.
One end of the capillary 3 and the other end of the moving coil 4
Is attached. The moving coil 4 is composed of a main coil 41 and a pressure coil 42 as shown in FIG. The number of turns of the main coil 41 is 20 times the number of turns of the pressure coil.
It has double the number of turns.

The moving coils 4 are each a permanent magnet 5.
1 and a yoke 52, which is present in the air gap of the magnetic circuit 5, constitutes a swinging motor which is a so-called short coil type VCM (voice coil motor), and supplies a current to the main coil 41 and the pressure coil 42. The arm 1 is driven by. The position and speed of the arm 1 are detected by a position detector 6 and a speed detector 7 attached to the shaft 2, respectively. The capillary 3 holds the gold wire 8 and presses the tip of the gold wire 8 against the bonding pad of the semiconductor pellet 9 for bonding.

Next, the operation of the wire bonding apparatus which is an embodiment of the present invention will be described with reference to FIG.

The speed command circuit 10 shown in FIG. 1 is set in advance so that the capillary 3 can move in a short time until the capillary 3 descends from above the pellet 9 to a predetermined height (search height) from the pellet 9. The speed command signal is output to the comparison circuit 11 in accordance with the profile, the difference signal output from the comparison circuit 11 is selected by the switching circuit 13, and the main coil 41 and the pressure coil of the moving coil 4 are both driven via the drive circuit 14. , The capillaries 3 operate according to the profile. When the capillary 3 reaches a predetermined height, a low speed constant speed (search speed) signal is output from the speed command circuit 10 to try to drive the capillary 3 at a low search speed. When the difference between the moving speed of the capillary 3 and the search speed becomes smaller than a predetermined fixed amount, the comparison circuit 11 sends a coil switching signal to the drive circuit 14.
Send to. The drive circuit 14 cuts off the current applied to the main coil 41 of the moving coil 4 and applies the current only to the pressurizing coil 42 to drive the capillary 3 at a low search speed and lower it until it contacts the pellet 9.

When the capillary 3 comes into contact with the pellet and the output of the speed detector 7 becomes zero, the switching circuit 13 selects a signal from the pressure command circuit 12 and applies a constant current to the pressurizing coil 42.
And a constant bonding pressure is applied to the pellet 9.

The pressing coil 42 has a thrust constant of the main coil 41.
Since it is only 1/20 compared with the above, it is possible to finely adjust the force generated by providing a current limiter on the pressure coil 43. Since the search speed is generally very low, it is insensitive to judge whether or not the capillary 3 has come into contact with the pellet. It does not apply any force.

Further, when the capillary 3 reaches the search height and the moving speed of the capillary 3 is settled to the search speed, the main coil 41 and the pressurizing coil 42 are simultaneously driven, so that a large thrust is obtained. Therefore, the moving speed of the capillary 3 can be set to the search speed in a short time.

[0017]

Since the wire bonding apparatus of the present invention uses only the pressure coil when the capillary contacts the pellet, it does not apply an excessive force to the pellet and also stabilizes the search speed. In this case, since the main coil and the pressure coil are used, the moving speed of the capillary settles at the search speed in a short time, so that the bonding time is short and the productivity of bonding is high.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a control system in an embodiment of the present invention.

FIG. 2 is a perspective view showing a mechanical system that is an embodiment of the present invention.

FIG. 3 is an enlarged view showing a part of the swing motor shown in FIG.

FIG. 4 is a perspective view showing a conventional wire bonding apparatus.

5 is an enlarged view showing a part of the swing motor shown in FIG.

FIG. 6 is a block diagram showing a configuration of a conventional control device shown in FIG.

[Explanation of symbols]

 1 Swing Arm 2 Axis 3 Capillary 4 Moving Coil 5 Magnetic Circuit 6 Position Detector 7 Speed Detector 8 Gold Wire 9 Pellet 10 Speed Command Circuit 11 Comparison Circuit 12 Pressure Command Circuit 13 Switching Circuit 14 Drive Circuit 15 Swing Motor 16 Switch 41 main coil 42 pressurizing coil 51 magnet 52 yoke 110 speed command circuit 111 comparison circuit

Claims (1)

Claim: What is claimed is: 1. A moving coil having at least two coils, a capillary at one end and a permanent magnet and a yoke at the other end. A swinging arm that is swingable with the moving coil and cooperates with the magnetic circuit to form a swinging motor;
Position detecting means for detecting the swing angle of the swing arm,
The moving coil of the wire bonding apparatus configured to include a speed detecting unit that detects a rocking speed of the rocking arm has a first coil and a second coil.
The number of turns of the coil is at least 10 times the number of turns of the second coil.
In the double wire bonding apparatus, the first coil and the second coil are detected while detecting output signals from the position detecting means and the speed detecting means until the capillary reaches a predetermined distance from the bonding pad of the semiconductor pellet. A current is applied to the coil to move the oscillating arm according to a predetermined profile, and after the capillary reaches the predetermined distance, the oscillating arm approaches the bonding pad at a constant speed and then the first coil. A current is applied to the second coil, and after the swing arm has settled at a constant speed, a current is applied only to the second coil so that the swing arm approaches the bonding pad at a constant speed, After the capillary comes into contact with the bonding pad and the output signal from the speed selecting means becomes zero, the second coil Wire bonding apparatus which comprises a means for controlling the current of the moving coil by applying a constant current to Le.