JPH04123550U - Lead frame - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to prevent deterioration in wire bonding properties in lead frames that are surface-treated to prevent deterioration in moisture resistance. [Configuration] The wire bonding area has been excluded from the surface processing target area.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to a lead frame used for assembling semiconductor devices, especially the surface of the lead part. Concerning the structure that prevents the deterioration of moisture resistance due to moisture entering through the bond between the Ru.

0002

[Conventional technology]

In some semiconductor devices with a resin-sealed structure, the Moisture may enter and bond the semiconductor chip adhered to the surface of the tab and the leads. As a measure to prevent the moisture resistance of wires from deteriorating, Some have surface treatments such as V-grooves and graining on the surface. In this case, traditionally A method has been adopted in which surface treatment is applied to the entire surface of the dot and tab parts that come into contact with the resin.

0003 Figure 3 shows the bonding state of bonding wires in a conventional lead frame of this type. An enlarged example is shown below. In the figure, 2 is a lead part and 4 is a bonding wire. Ru.

0004

[Problem that the idea aims to solve]

In conventional lead frames of this type, the wire bonding area of the leads also Since the surface has been treated, the bonding area between the bonding wire and the lead part is As shown in Figure 3, there are parts that are not bonded, which is unfavorable in terms of reliability. There was a problem. The present invention aims to solve the above problems.

[0005]

[Means to solve the problem]

The lead frame of this invention is a lead frame with surface treatment applied to the lead and tab surfaces. In the frame, move the wire bonding area of the lead part from the area to be surface processed. It has been excluded.

[0006]

【Example】

FIG. 1 shows an embodiment of the present invention. In the figure, 1 is the tab part, 2 is the lead part, and 3 is the tab part. The semiconductor chip is bonded to the surface of the tab part 1, and 4 is the electrode pad on the surface of the semiconductor chip 3. Bonding wire connecting lead part 2, 5 is external resin, 6 is internal resin, 7 is This is the wire bonding area, and Figure 1(a) shows the structure seen from above excluding the internal resin 6. Figure 1(b) is a cross-sectional view taken along line A-A shown in Figure 1(a). It is a diagram. A wire is placed on the flat surface of the wire bonding area 7, which is excluded from the surface processing target area. Since the ear 4 is bonded, the wire 4 is firmly bonded and the wire is stable. Bonding is obtained.

[0007] The lead frame with the above structure requires surface processing during stamping of the lead frame. A stage is set up to ensure that only the wire bonding area is covered with unprocessed gold. By surface processing method by mold, sandblasting, liquid honing Mask the wire bonding area to prevent surface processing. It can be obtained by a method in which the other parts are surface-treated.

[0008] Figure 2 is an enlarged view of the bonding state of wire 4 to the surface of wire bonding area 7 in Figure 1. and show. Due to the flat surface, reliable adhesion is obtained.

[0009]

[Effect of the idea]

As explained above, the present invention improves moisture resistance and improves wire bonding. This has the effect of increasing reliability.

[Brief explanation of drawings]

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

FIG. 2 is an enlarged view showing how wires are bonded to the surface of the wire bonding area in FIG. 1;

FIG. 3 is an enlarged view showing an example of the bonding state of bonding wires in a conventional lead frame of this type.

[Explanation of symbols]

1 Tab section 2 Lead part 3 Semiconductor chip 4 Bonding wire 5 External resin 6 Internal resin 7 Wire bonding area

Claims (1)

[Scope of utility model registration request] Claim 1: As a measure to prevent moisture from penetrating through the bond between the lead part surface and the resin from reaching the semiconductor chip adhered to the tab part surface and the wire bonded to the lead part, the lead part and the tab part surface are coated. A lead frame to which a surface treatment is applied, characterized in that a wire bonding area of a lead portion is excluded from a surface treatment target area.