Semiconductor device and lead frame used therefor

• US 4,809,053 A
• Filed: 08/12/1987
• Issued: 02/28/1989
• Est. Priority Date: 08/12/1986
• Status: Expired due to Term

• Current Assignee: Shinko Electric Industries Company Limited 711 AZA Shariden OAZA Kurita Nagano-Shi Nagano Japan
• Original Assignee: Shinko Electric Industries Company Limited (Fujitsu Limited)
• Inventors: Kuraishi, Fumio
• Primary Examiner(s): LaRoche, Eugene R.
• Assistant Examiner(s): Shingleton, Michael B.
• Application Number:
  US07/084,203
• Time in Patent Office: 566 Days
• Field of Search: 357/70, 357/81
• US Class Current: 257/675
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/48472 the other connecting portion not on the bonding area also being a wedge bond, i.e. wedge-to-wedge
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• CPC Class Codes: H01L 23/49517 Additional leads
• CPC Class Codes: H01L 23/49555 the bent parts being the outer leads
• CPC Class Codes: H01L 23/49568 specifically adapted to facilitate heat dissipation
• CPC Class Codes: H01L 24/48 of an individual wire connector
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/1532 the connection portion being formed on the die mounting surface of the substrate
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/1815 Shape

Abstract

A plastic molded semiconductor device which includes a metal lead frame having a heat spreader extending from a stage on which a semiconductor chip is mounted. The heat spreader is located between a periphery of the stage and inner leads located opposite to the stage. The chip is electrically connected to the inner leads by an insulative film having a plurality of conductive patterns.

Claims

1. A semiconductor device comprising:

a lead frame made of a metal strip including;

a rectangular stage;

at least one heat spreader extending outward from said rectangular stage for irradiating heat, said heat spreader having a substantially trapezoidal shape and having an edge which is one of a wave-shape, concave-shape, or convex-shape, for fixedly molding the heat spreader with a plastic material; and

a plurality of leads, each having inner and outer lead portions, inner ends of the inner lead portions being arranged along one or more sides of a rectangular area which is parallel to the periphery of said rectangular stage, said at least one heat spreader extending toward the inner ends of said inner lead portions from the periphery of said rectangular stage;

a semiconductor chip mounted on said stage and having a plurality of terminals;

means for electrically connecting said terminals of said semiconductor chip to respective ones of said inner lead portions; and

said plastic material for integrally molding said semiconductor chip, said connecting means, and said lead frame, so that at least said outer lead portions protrude outside said plastic material integrally molding said semiconductor chip.

2. A semiconductor device as set forth in claim 1, wherein said at least one heat spreader is bent in such a manner that a main part thereof is offset from said stage and positioned in the vicinity of an outer surface of said plastic material integrally molding said semiconductor chip.

3. A semiconductor device as set forth in claim 1, wherein said at least one heat spreader has one of slits and slots for fixedly molding said heat spreader with said plastic material.

4. A semiconductor device comprising:

a lead frame made of a metal strip including;

a rectangular stage;

at least one heat spreader extending outward from said rectangular stage for radiating heat, said at least one spreader having a substantially trapezoidal shape and having an edge having one of a wave-shape, concave-shape or convex shape for fixedly molding said heat spreader with a plastic material; and

a plurality of leads, each having inner and outer lead portions, inner ends of said inner lead portions being arranged along one or more sides of a rectangular area parallel to the periphery of said rectangular stage, said at least one heat spreader extending outward from the periphery of said rectangular stage toward the inner edges of said inner lead portions;

a semiconductor chip mounted on said stage and having a plurality of terminals;

an insulative film including a plurality of conductive patterns for electrically connecting said terminals of said semiconductor chip to said respective inner lead portions; and

said plastic material for integrally molding said semiconductor chip, said insulative film, and said lead frame, so that at least said outer lead portions protrude outside said plastic material integrally molding said semiconductor chip.

5. A lead frame made of a metal strip comprising:

a rectangular stage on which a semiconductor chip is mounted;

a plurality of leads having respective inner ends which are arranged along one or more sides of a rectangular area parallel to a periphery of said rectangular stage; and

at least one heat spreader having a substantially trapezoidal shape and having an edge having one of a wave-shape, concave shape, or convex shape, and extending from the periphery of said rectangular stage toward said inner ends of said leads arranged opposite thereto.

6. A semiconductor device as set forth in claim 5, wherein said at least one heat spreader is formed from one of slits and slots.