JPH0444420B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to wire bonder disconnection detection technology, particularly,
The present invention relates to a technique that is effective when applied to detect wire breakage during wire bonding to pellets by a wire bonder.

[Prior art] When bonding is performed using a wire bonder,
Breakage may occur due to the wire getting caught in the clamper, etc. If this disconnection occurs, if the disconnection is not detected as soon as possible and the bonding is interrupted, so-called blank bonding will occur, resulting in a large number of bonding defects.

Therefore, it is possible to detect disconnection for each wire, and one possible method is to detect the potential of a wire clamper.

[Problem to be solved by the invention] However, even when detecting disconnection for each wire,
The present inventor has discovered that if disconnection detection is incorrect for some reason, a large number of unwired defects will occur due to blank firing, and the problem will be that the defects cannot be discovered until the operator notices them.

In particular, when detecting disconnection in a method that uses a discharge torch to form a ball on the wire, it is conceivable to use a coil to detect the discharge current, but in this case there is a problem that detection reliability is lacking. There is.

Another possible method is to detect the potential of the energy charging capacitor on the secondary side of high voltage generation.
The inventors have found that reliable detection cannot be performed flexibly.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a wire bonder having a wire breakage detection function that can reliably detect wire breakage.

The above and other objects and novel features of the present invention will become apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] A brief overview of typical inventions disclosed in this application is as follows.

That is, wire bonding involves forming a ball on a wire using a discharge torch and bonding the wire to a pellet, which can be achieved by detecting the grounding state of the wire with a wire potential detection means.

[Operation] According to the above-described means, by preventing discharge when the wire is not grounded, it is possible to protect the device by preventing a voltage higher than the breakdown voltage from being applied to the device.

[Embodiment] FIG. 1 is a block diagram showing a wire breakage detection circuit which is an embodiment of a wire bonder having a wire breakage detection function according to the present invention.

In this embodiment, only the wire of the discharge circuit is directly grounded, and the ground potential of the wire is detected to control the discharge trigger, that is, the voltage.

That is, in this embodiment, the wire 1 is wound around the spool 2 with its proximal end being grounded, its distal end extending downward via the clamper 3 and capillary 4, and its lower end approaching the discharge electrode 5.

The trigger circuit 10 is a high voltage generating circuit 11.
The clamper 3 is connected to the trigger circuit 10 via a wire potential detection circuit (wire potential detection means) 12.

The discharge in this embodiment is caused by the high voltage generation circuit 11
This is done in the order of the positive electrode, the electrode 5, the capillary 4, the spool 2, the ground, and the negative electrode of the high voltage generating circuit 11.

Therefore, if the wire 1 breaks, for example, at part A and the spool end becomes ungrounded, it will become an open circuit and no discharge will occur, so it should be detected by the discharge detection circuit, but in reality it is a high When voltage is generated, various capacitance components are charged, resulting in discharge. Since the wires are not grounded, the charging voltage of these capacitors remains as the potential of the wires and is applied to the device during bonding on the pellet. Since this potential is higher than the element breakdown potential, it leads to element destruction.

Furthermore, since discharge occurs on the other hand, the discharge detection circuit determines that there is no wire breakage and continues the bonding operation, thereby destroying the elements one after another.

Therefore, in this embodiment, for example, the wire potential detection circuit 12 detects the potential of the clamper 3, and if it is not in the grounded state, the trigger circuit 10 is controlled so as not to generate a high voltage. Therefore, for example, if wire 1 becomes ungrounded due to disconnection at part A,
Since no discharge occurs, abnormalities can be detected.

Furthermore, in this embodiment, since no discharge occurs unless the wire 1 is grounded, it is possible to prevent the wire 1 from being discharged when it is not grounded, causing discharge energy to accumulate and exceed the element breakdown voltage, thereby destroying the element. .

As above, the invention made by the present inventor has been specifically explained based on examples, but the present invention is not limited to the above-mentioned examples, and can be modified in various ways without departing from the gist thereof. Needless to say.

For example, the discharge circuit may have a configuration other than those described above.

In the above description, the invention made by the present inventor has been mainly applied to the field of application for which it is applied, which is the disconnection detection of wire bonders. It can also be applied to discharge torches and other devices that use discharge circuits.

[Effects of the Invention] Among the inventions disclosed in this application, the effects obtained by typical inventions are briefly explained as follows.
It is as follows.

That is, the grounding state of the wire is detected by detecting the wire potential, and if the wire is not in the grounding state, no discharge occurs, thereby preventing the element from being destroyed.

Further, it is possible to obtain a wire bonder that can reliably detect wire breakage and prevent bonding defects from occurring.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing a wire breakage detection circuit which is an embodiment of a wire bonder having a wire breakage detection function according to the present invention. 1... wire, 2... spool, 3... clamper, 4... capillary, 5... electrode, 10...
Trigger circuit, 11... High voltage generation circuit, 12...
Wire potential detection circuit (wire potential detection means.

Claims (1)

[Claims] 1. A wire bonder that uses a discharge torch to form a ball on a wire and wire-bonds it to a pellet, which detects the grounding state of the wire using a wire potential detection means, and prevents discharge if the wire is not grounded. A wire bonder having a disconnection detection function, which protects an element by preventing a voltage higher than a breakdown voltage from being applied to the element.