JPH0621304A - Manufacture of lead frame and semiconductor device - Google Patents

Abstract

PURPOSE:To heighten close adhesiveness between an inner lead and resin while preventing generation of defectives such as a movement of a lead and a break of a wire by providing the half-etching part near a wire stitch bond of an inner lead. CONSTITUTION:A lead frame is constituted of an almost square die pad 1 loading an integrated circuit chip 5 and an inner lead 3 arranged in the periphery of said die pad 1 while having its one end facing the die pad 1. Until now, the vicinity of a wire stitch bond of the inner lead 3 was flat and tight adhesion between the inner lead 3 and resin was bad. However, tight adhesion between the inner lead 3 and resin can be heightened by providing a half-etching part 2 near the stitch bond so as to seal the inner lead 3 with resin and simultaneously therewith a movement of the lead 3 and a break of a wire ca be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame used for external lead assembly of a resin-sealed semiconductor device, and more particularly to a half-etched shape of the lead frame.

[0002]

2. Description of the Related Art As shown in FIG. 4, a conventional semiconductor device using a lead frame has a wire stitch bond (second bonding point at an internal lead terminal) of an inner lead 3 of the lead frame and an integrated circuit chip by a conductive wire 6. The wire bonding process for connecting to the pad portion 5 is one of the semiconductor device assembling processes. The surface roughness of the inner lead 3 of the lead frame is a member 42
The surface roughness as a material of Alloy and Cu remained as it was.

[0003]

However, in the method using the above-described conventional technique, the inner lead 3 is sealed with resin because the plane of the inner lead 3 portion of the lead frame is flat as shown in FIG. At that time, the adhesion between the inner lead 3 and the resin was deteriorated, and a package crack was generated when the package was soldered. Therefore, when the resin is thermally shrunk in the direction of arrow 7 as shown in FIG. 4, the inner lead 3 moves in the relative direction (in the direction of arrow 8), and the inner lead 3 moves or is bonded to the tip of the inner lead 3. There was a problem that the wire 6 was broken. Therefore, it is intended to provide a lead frame for overcoming the above problems.

[0004]

A lead frame according to the present invention is a lead frame which is arranged at a gathering edge of a substantially square die pad on which an integrated circuit chip is mounted and which is constituted by an inner lead whose one end faces the die pad. It is characterized in that half etching is provided near the inner lead stitch bond.

[0005]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. FIG. 1 is a sectional view of a die pad portion and an inner lead tip portion showing an embodiment of the present invention. The substantially square die pad 1 for mounting the integrated circuit chip 5 is supported by the die pad suspension leads at its four corners. The inner lead 3 inputs and outputs a signal to the chip 5 by bonding a pad on the integrated circuit chip 5 and the tip of the inner lead 3 with a wire 6.

An elongated half-etched portion 2 is provided laterally in the vicinity of the wire stitch bond of the inner lead 3.

FIG. 2 is also a plan view showing another embodiment of the present invention.

FIG. 2 shows a vertically elongated half-etched portion 4 provided near the wire stitch bond of the inner lead 3.

In the present invention, half etching has been described as having the same shape and the same distance from the tip of the inner lead, but this may have different shapes and different distances from the tip of the inner lead.

The half-etched portions 2 and 4 shown in FIGS. 1 and 2 shown above are provided on the surface of the lead frame.

FIG. 3 is a cross-sectional view of a die pad portion and an inner lead tip portion showing another embodiment of the present invention.

FIG. 3A shows a half-etched portion 9 provided on the back surface of the inner lead 3 near the wire stitch bond.

FIG. 3B shows the half-etched portions 10 provided on both surfaces of the inner lead 3 in the vicinity of the wire stitch bond.

FIG. 3C shows the inner lead 3 provided with a plurality of half-etched portions 11 on the front surface, the back surface, or both surfaces in the vicinity of the wire stitch bond.

Up to now, since the vicinity of the wire stitch bond of the inner lead is flat, the adhesion between the inner lead and the resin has deteriorated. However, in the present invention, by providing the half-etched portion shown above, the adhesion between the inner lead and the resin can be improved when the inner lead is sealed with the resin.

[0016]

As described above, in the present invention, by providing the half-etched portion in the vicinity of the wire stitch bond of the inner lead, the adhesion between the inner lead and the resin can be enhanced, and at the same time, the movement of the lead is moved. It has an excellent effect of preventing the occurrence of defects such as wire breakage.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a plan view showing another embodiment of the present invention.

FIG. 3A is a sectional view showing another embodiment of the present invention. (B) A sectional view showing another embodiment of the present invention. (C) A sectional view showing another embodiment of the present invention.

FIG. 4 is a sectional view showing a conventional technique.

[Explanation of symbols]

 1 ・ ・ ・ Die pad part 2, 4 ・ ・ ・ Half etching part 3 ・ ・ ・ Inner lead tip part 5 ・ ・ ・ Integrated circuit chip 6 ・ ・ ・ Wire 7 ・ ・ ・ Inner lead contraction direction 8 ・ ・ ・ Resin Shrinkage direction 9 ・ ・ ・ Half etching part 10 ・ ・ ・ Half etching part 11 ・ ・ ・ Half etching part

Claims (2)

[Claims] 1. A lead frame constituted by a substantially rectangular die pad on which an integrated circuit chip is mounted and an inner lead disposed at a gathering edge of the die pad and having one end facing the die pad, in the vicinity of a stitch bond of the inner lead. Lead frame characterized by half etching. 2. A method of manufacturing a semiconductor device, wherein the lead frame according to claim 1 is used.