KR980012384A - Lead frame with different inner lead edge - Google Patents

Abstract

The present invention relates to a lead frame, comprising: a die pad on which a chip is mounted; Internal leads spaced apart from the die pad; And outer leads formed integrally with the other ends of the inner leads integrally with each other, wherein lengths of the respective ends of the inner leads are differentiated to prevent defects of the respective bonding wires to be electrically connected to the ends of the inner leads, The present invention is characterized in that it is possible to flexibly cope with an ultra-multi-pin package and at the same time to fundamentally eliminate the defects of a bonding wire, by providing a lead frame in which an inner lead end is differentiated.

Description

Lead frame with different inner lead edge

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame, and more particularly, to a lead frame in which inner lead ends of a lead frame are arranged in zigzags so as to correspond to an ultra-multi-pin package.

The lead frame is a component of a package that allows a chip to be mounted and electrically connected to another external electronic device. The inner leads of the inner frame of the lead frame correspond to the number of bonding pads of the chip mounted on the lead frame. As the number of bonding pads on the chip increases, the width of the internal leads also becomes finer. However, since the width of the internal leads is limited to a certain extent, the fundamental problem can not be solved.

1 is a plan view showing a lead frame according to the prior art.

Referring to FIG. 1, the lead frame 100 has a die pad 20 on which a chip is mounted. Internal leads 40 are formed to be electrically connected to the bonding pads of the chip to be mounted, which are spaced apart from each other around the die pad 20. Here, the tip lengths and widths of the inner leads 40 are all the same. Further, the inner leads 40 have a structure integrally formed with the outer leads 50 to be bent in a predetermined form so as to be electrically connected to the external electronic device. A polyimide-based insulating adhesive 80 for preventing deformation is attached to the center portion of the inner lead 40.

When the chip to be mounted has a large number of bonding pads, the width of the internal leads is narrowed so that the bonding wires electrically connected to each other during the wire bonding process are sagging or sweeping ) Is generated.

2 is a plan view showing a state in which the wire bonding process is completed using one lead frame.

Referring to FIG. 2, in the conventional structure 200, the upper surface of the die pad 20 of the lead frame 100 and the lower surface of the chip 110 are bonded with an adhesive. At this time, the adhesive is silver (Ag) epoxy which is a non-electrically conductive adhesive. The bonding pads 112 formed on the upper surface of the chip 110 are electrically connected to the internal leads 40 of the lead frame 100 corresponding to the leads 112 and the bonding wires 130, . Reference numeral 50 denotes external leads.

In order to prevent the internal leads 40 from being deformed, an insulating tape 80 such as polyimide tape is bonded to the upper surface spaced apart from the electrical connection. As the number of the bonding pads 112 of the chip 110 increases, the number of the bonding pads 112 electrically connected to each other increases, The wires 130 are positioned close to each other and the sagging or sweeping of the upper bonding wires 130 is caused by the pressure of the molding resin due to the molding process.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method of manufacturing a semiconductor device, which can flexibly cope with an increase in the number of bonding pads and thereby prevent defects such as sagging or sweeping of a bonding wire, Lead frame.

FIG. 1 is a plan view showing a lead frame according to a related art; FIG.

FIG. 2 is a plan view showing a state in which the wire bonding process is completed using the lead frame of FIG. 1; FIG.

FIG. 3 is a plan view showing a lead frame in which an inner lead tip is differentiated according to an embodiment of the present invention; FIG.

FIG. 4 is a plan view showing a state in which a wire bonding process is completed using a lead frame of FIG. 3; FIG.

FIG. 5 is a plan view showing a lead frame in which an inner lead tip is differentiated according to another embodiment of the present invention; FIG.

FIG. 6 is a plan view showing a state in which the wire bonding process is completed using the lead frame of FIG. 5;

DESCRIPTION OF THE REFERENCE NUMERALS

80: insulating tape 120, 420: die pad

240, 440: first group inner lead 250, 450: second group inner lead

242, 442: inner lead tip 260, 270, 460, 470: outer lead

300, 500: lead frame 310, 510: chip

312, 314, 512, 514: bonding pads 330, 530: bonding wires

400, 600: Structure

In order to achieve the above object, a die pad on which a chip is mounted; A plurality of internal leads spaced apart from the die pad; And outer leads formed integrally with the other ends of the inner leads integrally with each other, wherein lengths of the respective ends of the inner leads are differentiated to prevent defects of the respective bonding wires to be electrically connected to the ends of the inner leads, And a lead frame having an inner lead tip differentiated from the lead terminal.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings. 3 is a plan view showing a lead frame in which an inner lead tip is differentiated according to an embodiment of the present invention.

FIG. 4 is a plan view showing a state in which the wire bonding process is completed using the lead frame of FIG. 3. FIG.

3 and 4, the structure 400 of the present invention has a structure in which the lead lengths of the inner leads of the lead frame 300 are set such that the first group and the second group inner leads 240 and 250 are differentiated Respectively. The internal leads 240 and 250 are electrically connected to bonding wires 330 for electrically connecting the bonding pads 312 and 314 of the chip 310 corresponding to the internal leads 240 and 250, Are much wider in the case where the number of bonding pads of the chip is increased as compared with the structure 200 shown in FIG. 2, it is possible to overcome the disadvantage of the conventional structure 200.

More specifically, the inner leads include first group inner leads 240 each having a long front end and second group inner leads 250 having a short front end. Here, the lengths of the first and second group inner leads 240 and 250 are the same for each group. Although the above-described group is exemplified as two, it is obvious that a plurality of groups can be formed as necessary. Except for the above description, since the lead frame and the structure using the lead frame described in the related art are the same, the detailed description will be omitted.

The shape of the tip of the inner leads illustrated in Figs. 3 and 5 is not limited to this, and can be modified or practiced according to the purpose. For example, "T" and "a".

Therefore, according to the structure of the present invention, it is possible to flexibly cope with the super-multi-pin package and at the same time to fundamentally eliminate defects of the bonding wire.

Claims (5)

A die pad on which chips are mounted; A plurality of internal leads spaced apart from the die pad; And outer leads formed integrally with the other ends of the inner leads integrally with each other, wherein lengths of the respective ends of the inner leads are differentiated to prevent defects of the respective bonding wires to be electrically connected to the ends of the inner leads, And a lead frame having a different inner lead end. 2. The lead frame according to claim 1, wherein a plurality of groups of the same lengths of the inner leads are formed. The leadframe according to claim 1 or 2, wherein the internal leads are differentiated by differentiating the widths of the respective ends of the internal leads. The leadframe according to claim 3, wherein the widths of the leading ends are formed so as not to be in mechanical contact with each other. The lead frame according to claim 1, wherein an inner lead is differentiated from the outer lead, characterized in that an insulating tape is attached to a central portion of the inner leads. ※ Note: It is disclosed by the contents of the first application.