JP2906753B2 - Lead frame - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lead frame,
In particular, the present invention relates to a lead frame used for lead assembly of a resin-sealed semiconductor device.

[0002]

2. Description of the Related Art FIG. 5 is a plan view of a conventional lead frame. The lead frame is made by punching or etching from a metal plate. The island 1 on which the semiconductor pellet is mounted is connected to and supported by the outer frame 4 by the suspension pin 5, and is arranged so that the tips gather around the island 1. It is connected by a plurality of inner leads 2a is data Iba 3 which is being supported integrally with the outer frame.

[0003] In such a lead frame, a semiconductor pellet is mounted on the island 1, an electrode of the pellet is connected to a tip of the internal lead 2a with a thin metal wire, and then the inside of the frame indicated by a dotted line is sealed with a resin. Then, each lead is separated from the outer frame 4 and the diver 3 to form an independent lead, and molding is performed to obtain a completed resin-encapsulated semiconductor device.

[0004]

SUMMARY OF THE INVENTION In a semiconductor device assembled and leaded using a conventional lead frame,
There is a disadvantage that noise such as ringing easily appears on the lead terminals during operation.

[0005]

The lead frame of the present invention, in order to solve the problems] includes islands to mount semiconductor pellet, have a plurality of inner leads disposed to surround the periphery of the island, and the tip portion of the internal lead A ferrite material is formed on at least one surface of the portion excluding the portion near the tie bar, and an insulator is provided between the ferrite material and the internal lead.
It is characterized by being interposed . In addition, the ferrite
A material covers the internal lead.

[0006]

FIG. 1A is a plan view showing a first embodiment of the present invention. FIG. 1B is a cross-sectional view taken along the line AA of FIG. 1A. For convenience, the width of the internal lead is illustrated as being the same.

In this embodiment, the surfaces of all the internal leads 2a are covered with an insulating material 6α such as epoxy resin except for the tip near the island and the portion on the side of the tie bar 3. 7α is provided. In the resin-encapsulated semiconductor device using the lead frame, noise such as ringing is reduced by the filter effect of the ferrite material.

In this embodiment, the internal leads are individually covered with an insulator. However, as shown in FIG. 2, an integrated insulator 6β may be used. Further, the ferrite material does not have to be cylindrical, and two flat ferrite materials 7γ1 and 7γ2 may be attached to the upper and lower sides of the insulator 6γ as shown in FIG.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

In this embodiment, a cylindrical ferrite material 7δ is provided so as to surround the internal lead 2 without interposing an insulator. Further, not all the internal leads are provided with the ferrite material 7δ, but are provided only on the internal leads corresponding to the signal terminals of the semiconductor device. The ferrite material 7δ may be formed by bonding two ferrite materials having a U-shaped cross section with an adhesive. This embodiment has an advantage that the ferrite material is provided closer to the internal lead, so that the noise filtering effect can be enhanced.

The ferrite material may be provided on either the front surface (the surface on which the semiconductor pellet is mounted) or the back surface of the internal lead.

[0012]

As described above, in the lead frame of the present invention, the ferrite material is provided in the vicinity of a certain area of the internal lead. There is an effect that generation of noise such as ringing due to the filter effect of the material can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of a first embodiment of the present invention (FIG. 1A).
And a sectional view (FIG. 1B).

FIG. 2 is a sectional view showing a modification of the first embodiment of the present invention.

FIG. 3 is a sectional view showing another modification of the first embodiment of the present invention.

FIG. 4 is a sectional view showing a second embodiment of the present invention.

FIG. 5 is a plan view showing a conventional lead frame.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Island 2a Internal lead 2b External lead 3 Tie bar 4 Outer frame 5 Hanging pin 6α, 6β, 6γ Insulator 7α, 7β, 7γ, 7δ Ferrite material

Claims (2)

(57) [Claims] And 1. A island mounting a semiconductor pellet, and have a plurality of inner leads disposed to surround the periphery of the island, at least one surface of the portion except the tip and the tie bar toward the portion of the internal lead A ferrite material is formed between the ferrite material and the internal lead.
A lead frame , wherein an insulator is interposed in the lead frame. 2. An island for mounting a semiconductor pellet.
And a plurality of
An internal lead, and a tip end of the internal lead and a tie bar.
-Ferrite on at least one side of the part excluding the near part
Material is formed, and the ferrite material covers the internal leads.
A lead frame characterized by being covered .