JPS5984533A - Feeding mechanism of wire - Google Patents

Abstract

PURPOSE:To keep a wire loop constant, and to execute stable wire bonding at all times by providing the wire-feed mechanism for feeding the wire for wire bonding with a back tension removing means removing the back tension of a spool. CONSTITUTION:The back tension removing member 7 drawing the wire 1 in the direction of a wire contacting plate 5 is set up between the spool 2 and the wire contacting plate 5. The back tension removing member 7 is formed by a member in which the tip of a wire such as a piano wire is formed to a loop shape and the wire 1 is inserted into the loop. The bringing of the spool 2 to the state of a back tension is removed by the function of the back tension removing member 7, and the wire 1 is brought into contact with the wire contacting plate 5 every time the wire 1 is bonded with the bonding pads of a pellet or a conductive section (not shown) such as a lead frame from a capillary 4. Accordingly, the wire 1 is fed smoothly at all times at every one wire because a spool driving motor 6 is operated and the spool 2 is driven in the direction of the wind-out of the wire.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire supply mechanism, and more particularly to a wire supply mechanism for supplying wire for wire bonding in a semiconductor assembly process.

Conventionally, as a wire supply mechanism of this type, a mechanism as shown in FIG. 1 has been used to supply a wire such as a gold wire. In this wire supply mechanism, the wire 1 is wound around a spool 2, and after the wire 1 is unwound from the spool 2, it is supplied to a capillary 4 via a clamper 3 to perform wire bonding. In this case, when the wire 1 comes into contact with the wire contact plate 5, the spool drive motor 6 drives the spool 2, and the wire 10 is unwound and supplied from the spool 2.

However, in this conventional mechanism, the spool 2 itself is not in a back tension state when the wire 1 is being supplied, and the wire 1 may not be smoothly supplied from the spool 2.

As a result, if the height of the wire loop after wire bonding is uneven, for example, if the wire is loose, the wire may come into contact with the pellet attachment tab or the edge of the pellet, resulting in a short or half-show F. state. There is a problem in that so-called tab short-circuit defects occur, resulting in a decrease in reliability.

The purpose of the present invention is to solve the problems of the prior art described above,
It is an object of the present invention to provide a wire feeding mechanism capable of keeping wire loops uniform and always performing stable wire bonding.

Hereinafter, details of the MK according to an embodiment of the present invention shown in the drawings will be explained.
explain.

FIG. 2 is a schematic explanatory diagram showing an embodiment of the wire supply mechanism according to the present invention, and parts corresponding to those of the conventional example shown in FIG. 1 are given the same reference numerals.

In this embodiment, a back tension removing member 7 is provided between the spool 2 and the wire contact plate 5 to pull the wire 1 in the direction of the wire contact plate 5. The back tension m>removal member 7 is made of, for example, a piece of piano wire with a looped tip and a wire 1 inserted into the loop.

In this embodiment, the action of the pack tensidin removal member 7 prevents the spool 2 from becoming exposed to the back ten, and the wire 1 is removed from the cavity 24 to the pellet's pounding pad or lead frame. Each time the wire 1 is bonded to a conductive part (not shown) such as the wire 1, the wire 1 contacts the wire contact plate 5. Thereby, the spool drive motor 6
operates and drives the spool 2 in the wire unwinding direction, so that the wire 1 is always smoothly supplied one wire at a time.

Therefore, the loop of the wire 1 in this embodiment is uniform, and the wire loose height can be freely controlled, so that the bonding speed of the wire bonder can be adjusted to match the wire contact. Even at high speeds such as 90.4 seconds or less, wire is always supplied reliably.

Highly reliable wire bonding can be obtained.

As a result, the quality and reliability of semiconductor products are improved, and the amount of shear wire used is stabilized by making loose wires more uniform.

Note that the present invention is not limited to the above embodiments,
For example, the pack tension removing member 7 may have various structures other than one using piano wire, and may have any structure as long as it can remove the back tension of the spool 20.

As explained above, according to the present invention, the back tension of the spool can be removed, the wire looseness can be made uniform, and the wire loop height can be freely controlled.
Stable wire bonding can always be performed reliably, and so-called tapsi rot defects and the like can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an example of a conventional wire supply mechanism, and FIG. 2 is a schematic explanatory diagram showing an embodiment of the wire supply mechanism according to the present invention. 1...Wire, 2...Spool, 3...Cruncher, 4゛°capillary, 5...Wire contact plate, 6...
- Spool drive motor, 7... pack tension removal member. Figure 1 Figure 2

Claims (1)

[Claims] 1. A spool wound with a wire, a wire contact member capable of contacting the wire unwound from the spool, and a wire contact member that drives the spool when the wire comes into contact with the wire contact member. A wire supply mechanism having a spool driving means for unwinding a predetermined amount of wire from the wire, characterized in that a pack tension removing means for removing pack tension of the spool is provided between the spool and the wire contact member. Wire feeding mechanism. 26. The wire feeding mechanism of claim 1, wherein the puck tension removal means applies stress to the wire to displace the wire in the direction of the wire contacting member.