JPH0148656B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire bonding apparatus, and more particularly to a wire bonding apparatus capable of detecting wire breakage, bonding failure, wire termination, etc.

In a wire bonding device, a spool around which a wire is wound is used, as shown in, for example, JP-A-53-94178 (hereinafter referred to as known example 1) and JP-A-53-39065 (hereinafter referred to as known example 2). An air guide is placed between the wire and the capillary, and gas is blown onto the wire to give tension to the wire. This prevents the wire from sagging and controls the shape of the wire loop to be bonded. In addition, in order to always supply a fixed amount of wire between the spool and the capillary, a detection plate is installed directly above the air guide. When the wire comes into contact with this detection plate, the motor that drives the spool rotates, and the wire We are providing supplies.

By the way, in such a wire bonding apparatus, in order to detect wire breakage, as shown in the above-mentioned known example 1, a current is passed between the wire and the pellet electrode or the lead side electrode, and the wire is connected to the pellet electrode or the lead side electrode. A detector detects whether it is connected to the However, since passing a current through the pellet electrode has an adverse effect on the semiconductor characteristics, it is preferable not to pass a current, even a minute current.

Therefore, current is applied and detected only during bonding of the lead-side electrode. By the way, if a wire breakage occurs and the wire is completely removed from the capillary, it is sufficient to detect it only during bonding of the lead-side electrode as described above. However, if the wire is not bonded to the pellet electrode but is bonded only to the lead side electrode with the wire extending from the tip of the capillary,
That is, if no wire is stretched between the pellet electrode and the lead-side electrode, defective bonding of the pellet electrode cannot be detected by detecting only when the lead-side electrode is bonded as described above. Therefore, in the past, although it is not preferable, the current situation is that a minute current is passed during bonding of the pellet electrode for detection.

In addition, in order to detect whether or not the wire wound around the spool has ended, as shown in the above-mentioned known example 2, an electrode terminal for wire end detection is installed inside the drawn out wire and at a position close to the bottom of the spool. When the wire wound around the spool is finished, the position at which the wire is pulled out changes from the tangential direction of the wire winding circle of the spool, and the wire comes into contact with the electrode terminal. In this way, in order to detect the wire end, it is necessary to provide a wire end detection device separately from the wire breakage detection device described above.
It has the disadvantage of being expensive.

The present invention provides a wire bonding device that can detect wire supply, wire breakage, poor wire connection, wire termination, etc. with a single detection plate, and does not require voltage to be applied to pellet electrodes and lead electrodes for this detection. The purpose is to provide

Hereinafter, the present invention will be explained with reference to illustrated embodiments.
FIG. 1 is a schematic diagram showing an embodiment of the wire bonding apparatus according to the present invention, and FIG. 2 is a detection circuit diagram of the same apparatus. As shown in FIG. 1, a wire 3 is wound around a spool 2 driven by a motor 1. As shown in FIG. Wire 3 fed from spool 2
are air guide 4, wire guide 5, clamper 6
through it to the lower end of the tool 7. A detection plate 9 is fixed to the upper surface of the air guide 4 so as to face the gas blowing direction 8 of the air guide 4 and come into contact with the wire 3 . The detection plate 9 is the detection circuit 1
0, and the detection circuit 10 is connected to the motor 1 and the microcomputer 20. Here, the air guide 4 and the detection plate 9 are insulated individually and from the bonding body (not shown). At least one of the spool 2, wire guide 5, clamper 6, and tool 7 is formed of a conductor and is grounded to the bonding body.

As shown in FIG. 2, the detection plate 9 is connected to a detection plate detection comparator 11, and the signal 11a of the detection plate detection comparator 11 is input to a first detector 12 and a second detector 13, respectively, which are comprised of flip-flop circuits. be done. The first detector 12 outputs a wire contact presence/absence result signal 12a, and the second detector 13 outputs a spool driving display signal 1.
3a is output, and these signals 12a and 13a are input to the microcomputer 20. A wire connection detection start signal 20a and a spool drive start signal 20b are input from the microcomputer 20 to the first and second detectors 12 and 13, respectively. Further, the spool drive stop signal 20c outputted from the microcomputer 20 is inputted to the second detector 13 via the OR circuit 14 together with the signal 11a of the detection plate detection comparator 11. Further, the spool drive display signal 13a from the second detector 13 is input to the spool drive motor 1 via the motor drive amplifier 15. Further, one terminal of the DC current 16 is connected to the detection plate detection comparator 11 through a resistor 17 so that a minute current flows through the detection plate 9 and the detection plate detection comparator 11.
is connected to the connection line between one input part of the detection plate 9 and the other terminal is connected to the other input part of the detection plate detection comparator 11 via the resistor 18, and the other terminal of the detection plate detection comparator 11 The input section of is grounded via a resistor 19.

Next, the operation will be explained with reference to FIG. first,
As shown in FIG. 3a, the tool 7 is moved above the first bond point 30, which is a pellet electrode. In this state, since the wire 3 is sufficiently supplied from the spool 2, the detection plate 9 is
is in contact with. From this state, the tool 7 is lowered to perform bonding at the first bonding point 30, as shown in FIG. Next, the clamper 6 is opened, and the tool 7 rises and moves above the second bonding point 31, which is the lead-side electrode. Subsequently, as shown in FIG. 3c, the tool 7 is lowered to perform bonding at the second bonding point 31. In this operation, the following conditions appear.

The first state is the state shown in FIG. 3c. That is, in the operations shown in FIGS. 3b to 3c, the wire 3 is consumed by wire bonding, and the wire 3 becomes separated from the detection plate 9 as shown in FIG. 3c.

The second state is the state shown in FIG. That is, the first
If the wire 3 is not bonded at the bonding point 30, the wire 3 will not be consumed, and the wire 3 will be in contact with the detection plate 9 as shown in FIG.

The third state is the state shown in FIG. That is, the wire 3 is cut and comes out of the tool 7, and as shown in FIG. 5, the wire 3 is blown up by the air guide 4 and comes into contact with the detection plate 9.

Only the first state is a case of normal operation, and the second and third states are cases of abnormal operation.

Therefore, when the tool 7 starts descending, the microcomputer 20 inputs the wire connection detection start signal 20a to the first detector 12, sets the output signal 12a of the first detector 12 to a low level, and detects whether the wire is present or not. Start detection. This wire presence detection is performed until the tool 7 descends to the second bonding point 31.

In the first state shown in FIG. 3c, the wire contact signal 11a from the detection plate detection comparator 11 is is not output, and the wire contact presence/absence result signal 12a of the first detector 12 remains at a low level,
It is judged to be operating normally.

However, in the second and third cases of FIGS. 4 and 5, the wire 3 is in contact with the detection plate 9.

First, the case shown in FIG. 4 will be explained. In this case, since at least one of the wire spool 2, wire guide 5, clamper 6, and tool 7 is a conductor, the wire 3 is grounded to the main body (not shown), and the wire 3 is connected to the detection plate 9 as shown in FIG. When it comes in contact with the wire 3, current flows from the power source 16 through the detection plate 9 to the wire 3, and the detection plate detection comparator 11
The wire contact signal 11a is output from the first detector 12, and the wire contact presence/absence result signal 12a of the first detector 12 becomes a high level. In this case, the tool 7 rises as shown in FIG. 3e, which will be explained later, and when it moves to the next wire bonding point, the microcomputer 20 outputs an abnormality display signal and the operation is stopped.

Next, the case shown in FIG. 5 will be explained. In this case, the time of detection differs depending on whether the wire spool 2 is a conductor or an insulator. That is, when the wire spool 2 is a conductor, the wire 3 is grounded to the main body, so current flows from the power source 16 to the wire 3 through the detection plate 9, and an abnormality occurs as in the case of FIG. is detected. However, wire spool 2
When is an insulator, the wire 3 is not grounded to the main body, so the wire contact signal 11a is not output from the detection plate detection comparator 11, and the wire contact presence/absence result signal 12a remains at a low level. , at this point, it is considered normal operation as in the case of FIG. 3c.

After detecting the presence or absence of the wire as described above, the spool drive start signal 20b is input from the microcomputer 20 to the second detector 13, and the spool drive signal 13a of the second detector 13 becomes high level and the motor 1
is rotated, and the wire 3 is supplied from the spool 2.

When the wire 3 is normally supplied, the wire 3 contacts the detection plate 9 as shown in FIG. 3d. Therefore, the signal 11a of the detection plate detection comparator 11 is
The spool drive signal 13a is input to the detector 13, and the spool drive signal 13a of the second detector 13 becomes a low level, and the rotation of the motor 1 is stopped.

The spool drive start signal 20b is output, and the second bond point 31 is bonded at the same time as the wire is supplied. After the bonding is completed, the clamper 6 is closed, the clamper 6 is raised, and the wire 3 is cut from the base of the second bonding point 31. After cutting the wire, the tool 7 rises as shown in FIG. 3e, and the clamper 6 feeds out the wire 3 below the tip of the tool 7, moving to the next bonding point, resulting in the state shown in FIG. 3a.

After the movement is completed, the microcomputer 20 determines whether the spool drive signal 13a is at a low level or a high level. If the level is high, motor 1
is rotating, the microcomputer 20
The spool drive stop signal 20c is input to the second detector 13, and the spool drive signal 13a becomes low level, causing the motor 1 to stop. Motor 1
At the same time, the microcomputer 20 outputs an abnormality display signal to stop the operation.

If the wire spool 2 is made of an insulating material as described above, the wire 3 is not grounded to the main body (not shown) in the state shown in FIG. Even if the wire feeding operation is performed, the motor 1 continues to rotate because the detection plate 9 considers that there is no wire. When the detection plate 9 has no wire,
Since the spool drive signal 13a becomes high level,
It was determined that there was an abnormality in the wire, and microcomputer 2
Outputs an abnormality display signal from 0 and stops the operation.

Furthermore, even if the motor 1 rotates from the state shown in FIG.
That is, when the wire 3 is not wound even one turn around the spool 2, the wire 3 is unwound as shown in FIG.
does not come into contact with the detection plate 9. In this case, an abnormality display signal is outputted and the wire bonding operation is stopped by the same operation as that shown in FIG. 5 described above.

In this way, the detection plate 9 is placed in contact with the wire 3 facing the gas blowing direction 8 of the air guide 4.
is fixed to the air guide 4, and the second bond point 3
1, whether or not the wire 3 has contacted the detection plate 9 at the time when the tool 7 is lowered, and after this detection, the motor 1 is rotated to supply the wire 3, and while the tool 7 is moving to the next bonding point. The detection plate 9 is connected to the wire 3
It is grounded to the main body (not shown) by contacting the motor 1, and detects bonding failure, wire breakage, and wire termination depending on whether or not the motor 1 has stopped.
Outputs an error message and stops operation.

As is clear from the above description, according to the present invention, wire breakage, bonding failure, and wire termination can be detected using one detection plate, so that an inexpensive device can be obtained. Further, since no voltage is applied to the semiconductor to detect wire breaks or bonding defects, there is no adverse effect on the characteristics of the semiconductor.

[Brief explanation of drawings]

Fig. 1 is a schematic diagram showing an embodiment of the wire bonding device according to the present invention, Fig. 2 is a detection circuit diagram of the same device, Figs. 3 a to e are explanatory diagrams of the operation in a normal bonding state, and Fig. 5 is an explanatory diagram of the operation when the wire is not bonded to the first bond point, FIG. 5 is an explanatory diagram of the operation when the wire is removed from the tool, and FIG. 6 is an explanatory diagram of the operation when the wire is finished. DESCRIPTION OF SYMBOLS 1... Motor, 2... Spool, 3... Wire, 4... Air guide, 7... Tool, 8... Gas blowing direction, 9... Detection plate, 10... Detection circuit.

Claims (1)

[Claims] 1. In a wire bonding device in which an air guide is disposed between a spool around which a wire is wound and a tool and a tool is provided to apply tension to the wire by blowing gas onto the wire, the wire is contacted in a direction opposite to the gas blowing direction of the air guide. A detection plate is fixed to the air guide, and a detection circuit is attached to the detection plate for detecting whether or not a wire is in contact with the detection plate and outputting an abnormal signal and a signal for driving the spool drive motor. Wire bonding equipment connected to.