JPS6256659B2 - - Google Patents

Abstract

PURPOSE:To prevent the exfoliation of a bonding section by a method wherein a tool is elevated after the second bonding, a clamper is closed, and circular arcs are described backward or the clamper is dropped rectilinearly, a neck section is easy to be cut, and a wire is cut. CONSTITUTION:A pellet 1 and an external lead 2 are connected by the wire 4 inserted into the tool 3. The tool 3 is elevated, and the clamper 5 is closed. The tool 3 and the clamper 5 backward describe circular arcs centering around the neck section 4a, and drop. Accordingly, the neck section 4a is easy to be cut because the wire 4 is turned centering around the neck section 4a. The tool 3 and the clamper 5 are backward moved just before the wire 4 contacts with the upper surface of the external lead 2, and cut from the neck section 4a. The wire 4 is previously brought to a delivered state under the state. The tool 3 is elevated, and moved onto the pad of the pellet to be bonded, and said operation is repeated, thus completing wire bonding.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a wire bonding method in which a semiconductor pellet serving as a first bonding point and an external lead serving as a second bonding point are connected by a wire inserted through a tool of a wire bonding apparatus. This invention relates to a wire cutting method.

A conventional wire bonding method is performed as shown in FIG. That is, as shown in FIG. 1A, the pellet 1 and the external lead 2 are connected by a wire 4 inserted through a tool 3. Next, as shown in FIG. 3B, the tool 3 is raised, and then the clamper 5 is closed. Subsequently, the tool 3 is moved backward to cut the wire 4, as shown in FIG. In addition, in the figure, 6
is an ultrasonic oscillation horn holding a tool 3 at one end, which is attached to a bonding head (not shown).

In this way, conventionally, the wire 4 is cut by simply moving the tool 3 backward, so the wire neck 4a
When the tool 3 is moved from the state shown in FIG. 3B to the state shown in FIG. Furthermore, the wire cutting position varies due to the difference in strength of the wire neck 4a, making it difficult to maintain a constant tail length under the tip of the tool.

The present invention was made in view of the above-mentioned drawbacks of the prior art, and it is an object of the present invention to provide a wire bonding method that can obtain good bonding and always maintain a constant tail length.

Hereinafter, the present invention will be explained with reference to illustrated embodiments.

FIG. 2 is an operational explanatory diagram showing an embodiment of the wire bonding method according to the present invention. The present invention performs the operations shown in FIGS. 1a and 1b in the same manner as in the prior art. That is, as shown in FIG. 1a, the pellet 1 and the external lead 2 are connected by a wire 4 inserted through a tool 3. Next, the tool 3 is raised as shown in FIG. 1b, and then the clamper 5 is closed.

Next, as shown in FIG. 2a, the tool 3 and the clamper 5 descend in a backward arc around the neck portion 4a of the wire 4. As a result, the wire 4 rotates around the neck portion 4a, making it easier to break the neck portion 4a. Then, just before the wire 4 under the tip of the tool 3 contacts the upper surface of the external lead 2, the tool 3 and the clamper 5 are connected to each other as shown in FIG. 2b.
is moved backward and the wire 4 is cut from the neck portion 4a. In this state, the wire 4 has already been paid out under the tip of the tool 3. Next, as shown in FIG. 2c, the tool 3 is raised, and then moved onto the pad of the next pellet to be bonded, and by repeating the above operations, wire bonding of one semiconductor component is completed. Complete.

In the above embodiment, the tool 3 descends in an arc in the operations from FIG. 1b to FIG. 2a, but it may be lowered linearly diagonally backward. Immediately after cutting the wire 4 as shown in Fig. 2b, the tool 3 was raised as shown in Fig. 2c. Lower it and ground it by sandwiching the wire 3 between the external leads 2 and
The tool 3 may then be raised.

As is clear from the above description, according to the wire bonding method of the present invention, after the second bonding, the tool is raised, the clamper is closed, and the tool is then lowered in a backward arc or in a straight line. The wire under the tip of the tool is moved backwards to cut the wire just before the wire under the tip of the tool touches the bonded sample, so the bonding portion does not peel off and the wire under the tip of the tool is cut easily. The variation in the tail is also reduced.

[Brief explanation of the drawing]

The figure shows the wire bonding method;
2 to 2c are explanatory diagrams of the operation of the conventional example, and FIGS. 2a to 2c are explanatory diagrams of the operation of an embodiment of the present invention. 1... Pellet, 2... External lead, 3... Tool, 4... Wire, 5... Clamper.

Claims (1)

[Claims] 1 In a wire bonding method in which a first bond point and a second bond point are connected by a wire inserted through a tool of a wire bonding device, the second bond point is
After bonding to the bonding point, the tool is raised, then the clamper is closed, and then the tool is lowered in a backward arc or diagonally downward in a straight line, so that the wire under the tip of the tool is grounded to the bonded sample. A wire bonding method in which the tool is moved backwards and pulled to cut the wire just before the wire is cut.