JPH02133934A - Wire-clamping mechanism - Google Patents

Abstract

PURPOSE:To surely hold a metal thin wire without being detached and to smoothly execute an automatic operation of a wire bonding apparatus by a method wherein a plurality of slits are formed at the tip part of a cylindrical member through which the metal thin wire is passed, a plurality of claws surrounding a periphery of the metal thin wire are formed and the claws are closed. CONSTITUTION:Since electricity is not applied to an electromagnetic coil 8 in a usual case, a movable member 4 is pulled by a spring 5 and is kept shifted to the upper part. At the tip of a cylindrical member 2, claws 13 are opened and a metal thin wire 9 is not held. Then, when the electricity is applied to the electromagnetic coil 8, the movable member 4 is lowered by a flux force of the electromagnetic coil 8; at the tip of the cylindrical member 2, the claws 13 are closed and the metal thin wire 9 is held.

Description

Detailed Description of the Invention [Industrial Field of Application] -m, a wire bonding device is used to bond electrode pads of a semiconductor chip having electrode pads, which are electronic circuits and input/output terminals, formed on the surface thereof, and a lead frame. It is used for welding and connecting the internal leads of the metal wire with thin metal wire. In particular, in recent years, with the automation and speeding up of this work, various improvements have been made so that each mechanical part of the wire bonding device can operate smoothly and at high speed. One of the typical mechanisms is a wire clamp mechanism, for example.

FIG. 3 is a perspective view of a conventional wire clamp mechanism. The wire clamp mechanism is a mechanism that holds a thin metal wire when the thin metal wire is supplied from a spool or when the thin metal wire is cut after being welded.

As shown in FIG. 3, this wire clamp mechanism is composed of two plates 1 and a clamp pad 10 attached to the tips of the plates 1.

When feeding the thin metal wire 9 to the bonding tool, the clamp pad 10 is moved by pneumatic pressure and electromagnetic force.
It grasps and holds the thin metal wire 9.

Next, by lowering this wire clamp mechanism,
A thin metal wire 9 is unwound and supplied from a spool fixed at the top.

When cutting the thin metal wire 9, one end of the thin metal wire 9 welded to the electrode pad of the semiconductor chip is grasped and held, and the wire clamp mechanism is raised to apply a tensile force to the thin metal wire and cut it.

[Problem to be solved by the invention]

In the conventional wire clamp mechanism described above, the thin metal wire is held between only the clamp pads on both sides, so the thin metal wire often fluctuates due to machine vibrations and comes off from the clamp pads. For this reason, there is a problem that automation work does not proceed smoothly.

SUMMARY OF THE INVENTION An object of the present invention is to provide a wire clamp mechanism that can reliably hold a thin metal wire without coming off and can smoothly automate the wire bonding apparatus.

[Means to solve the problem]

The wire clamp mechanism of the present invention is a wire clamp mechanism that holds a thin metal wire of a wire bonding device that welds and connects an electrode pad of a semiconductor chip and an internal lead of a lead frame with a thin metal wire. It has a tapered cylindrical part with a plurality of slots of a predetermined length from the end face formed on one end side, and a tapered cylindrical part whose outer diameter becomes larger as it approaches the end face, and the other end has a predetermined length from the end face. a cylindrical member having an equal diameter, and a ring-shaped member inserted to be slidably fitted into the equal diameter portion of the cylindrical member;
The ring-shaped member is provided with a movable mechanism that moves the ring-shaped member toward the end surface of the cylindrical member where the slot is formed and toward the equal diameter portion of the cylindrical member.

〔Example〕

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

FIG. 1 is a partial cross-sectional view of a wire club mechanism showing one embodiment of the present invention, and FIGS. 2 (a> and (b) are partial cross-sectional views for explaining the operation of the ring-shaped member in FIG. 1. This wire clamp mechanism has a hole in the center through which a thin metal wire 9 is passed, a plurality of slots 11 having a predetermined length from the end face are provided on one end side, and a plurality of claws 13 are formed.
A cylindrical member 2 has a tapered cylindrical part whose outer diameter is larger as it approaches the end face, and the other end has an equal diameter part of a predetermined length from the end face. It has a ring-shaped member 3 that is inserted so as to fit together, and a movable mechanism 12 that moves the ring-shaped member 3 to the tip or rear end of the cylindrical member 2.

The horizontal part 12 of the rotating machine includes a movable member 4 having a ring-shaped member 3 attached to one end to be inserted into the cylindrical member 2 and two guide posts 7 embedded in the upper surface of the other end. A spring 5 installed between the guide posts 7;
A bush (not shown) that slides on the guide post 7 is embedded, a hole at one end of which is inserted into the cylindrical member 2, and a bracket 6 is fixed to the cylindrical member 2, and a bracket 6 is mounted on the bracket 6 in a manner corresponding to the spring 5. It is composed of an electromagnetic coil 8 arranged.

Next, the operation of holding the thin metal wire 9 using this wire clamp mechanism will be explained. Normally, the electromagnetic coil 8 is not energized, so the movable member 4 is pulled by the spring 5 and remains moved upward, as shown in FIG. Moreover, the tip of the cylindrical member 2 is as shown in FIG. 2(b).
The claw 13 is open and the thin metal wire 9 is not held.

Next, when the electromagnetic coil 8 is energized, the movable member 4 is lowered by the magnetic flux force of the electromagnetic coil 8, and the tip of the cylindrical member 2 is closed by the claw 13, as shown in FIG. Hold the thin wire 9.

〔Effect of the invention〕

As explained above, the present invention forms a plurality of slots at the tip of a cylindrical member through which a thin metal wire is passed, and provides a plurality of claws that wrap around the thin metal wire. Since the thin metal wire can be held, there is an effect that a wire clamp mechanism can be obtained that can reliably hold the thin metal wire without coming off and can smoothly proceed with the automation work of the wire bonding device.

[Brief explanation of the drawing]

1 is a partial sectional view of a wire club mechanism showing an embodiment of the present invention, FIGS. 2(a) and 2(b) are partial sectional views for explaining the operation of the ring-shaped member in FIG. FIG. 3 is a perspective view of a conventional wire clamp mechanism. DESCRIPTION OF SYMBOLS 1... Plate, 2... Cylindrical member, 3... Ring-shaped member, 4... Movable member, 5... Spring, 6... Bracket, 7... Guide post, 8...・・Electromagnetic coil, 9
...Thin metal wire, 10...Clamp pad, 11...
Slot, 12... Movable mechanism, 13... Claw.

Claims (1)

[Claims] In a wire clamp mechanism that holds the thin metal wire of a wire bonding device that welds and connects the electrode pad of a semiconductor chip and the internal lead of a lead frame with a thin metal wire, the wire clamp mechanism has a hole in the center for passing the thin metal wire and has a hole on one end side from the end surface. A cylindrical member having a tapered cylindrical part in which a plurality of slots of a predetermined length are formed and whose outer diameter becomes larger as it approaches the end face, and the other end is a predetermined length from the end face and has an equal diameter. , a ring-shaped member inserted so as to be slidably fitted into the equal-diameter portion of the cylindrical member; and a ring-shaped member inserted into the end surface side of the cylindrical member where the slot is formed and the equal-diameter portion side of the cylindrical member. A wire clamp mechanism characterized by having a movable mechanism for moving the wire.