JPH03230556A - Lead frame for semiconductor device - Google Patents

Abstract

PURPOSE:To prevent punching of corners, failure in adhesion, and deformation or sagging of a wire by mechanically flattening a tip of an inner lead of a lead frame to increase its area. CONSTITUTION:An area of the tip is increased by mechanically processing a tip of an inner lead 1 of a lead frame for a semiconductor device to have it flattened 1a. By thus increasing the area of the tip by means of flattening the tip of the inner lead 1 with respect to the lead frame etching-molded, a width of the inner lead to be required for wire bonding can be secured, and good wire bonding is possible since a long wire is not necessary.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a lead frame for a semiconductor device used when connecting wires such as gold wires or copper wires to a semiconductor element having a large number of electrodes such as an integrated circuit.

Conventional technology Conventionally, when connecting lead wires from the electrode section of a semiconductor device to the outside, the tips of the inner leads provided at the center of an etched lead frame and the electrode section provided on the top surface of the semiconductor device are used. It is common to perform so-called wire bonding with wires such as gold wires or copper wires.

Problems to be Solved by the Invention However, in the conventional lead frame for semiconductor devices, when the distance between the tips of the inner leads of the lead frame is reduced as the number of bins in semiconductor devices progresses, the lead frame is removed by etching. Since the width of the gap between the tips of the frame is limited by the thickness of the lead frame material, it is difficult to secure a sufficient width of the tips of the inner leads required for wire bonding, resulting in cornering and wire sagging during wire bonding. , non-delivery, etc. occur as issues. In addition, in order to obtain a sufficient tip width of the inner lead, a method is used to move the tip part away from the electrode pad on the semiconductor chip, but in this case, the length of the wire becomes extremely long, making wire bonding difficult. There was a problem that sometimes wire sag or wire deformation occurred.

The present invention solves the above-mentioned conventional problems, and provides a semiconductor device that can ensure a wide tip width of the inner lead and enable good wire bonding without increasing the length of the wire. The purpose of this invention is to provide lead frames for

Means for Solving the Problems In order to achieve the above object, the present invention machine-processes the tips of inner leads of lead frames for semiconductor devices to make them flat and increase the area of the tips.

Therefore, according to the present invention, the width of the tip of the inner lead required for wire bonding is ensured, and there is no need to increase the length of the wire, so that good wire bonding can be performed.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to FIGS. 1 to 3. In FIG. 1, 1 is an inner lead, 1a is a tip of the inner lead which has been flattened by machining and has an area enlarged from the center, 2 is a die pad,
3 is an outer lead, and 4 is an outer frame portion of the lead frame. FIG. 2 shows the tip of the inner lead 1 of the lead frame after etching forming, and when the tip is flattened by machining, the tip 1a as shown in FIG.
becomes.

As is clear from FIGS. 2 and 3, by machining (pressing, etc.) the tip of the inner node 1 of the lead frame after etching,
The area of the tip is enlarged.

By flattening the tips of the inner leads 1 and increasing the area of the tips for the etched lead frame, it is possible to secure the width of the inner leads required for wire bonding. Since there is no need to increase the length of the wire, good wire bonding can be performed.

Effects of the Invention As is clear from the above embodiments, the present invention mechanically flattens the tip of the inner lead of the etched lead frame to increase its area. This has the effect of preventing wire deformation, sag, etc.

[Brief explanation of drawings]

FIG. 1 is a partial plan view of a lead frame for a semiconductor device according to an embodiment of the present invention, and FIG. 2 is an enlarged perspective view of the tip of the inner lead of the lead frame after machining and sowing molding.
FIG. 3 is an enlarged perspective view of the tip of the inner lead after machining. 1... Inner lead, 1a... Inner lead tip after machining.

Claims (1)

[Claims] A lead frame for a semiconductor device including an inner lead electrically connected to an electrode part of the semiconductor device, wherein the tip of the inner lead is flattened so that its area is larger than that of the center part. flame.