Resin-sealed semiconductor device having island for mounting semiconductor element coupled to heat spreader

• US 6,258,630 B1
• Filed: 02/01/2000
• Issued: 07/10/2001
• Est. Priority Date: 02/04/1999
• Status: Expired due to Term

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: NEC Corporation
• Inventors: Kawahara, Yoshinori
• Primary Examiner(s): Picardat, Kevin M.
• Application Number:
  US09/494,927
• Time in Patent Office: 525 Days
• Field of Search: 438/111, 438/112, 438/122-127, 257/666, 257/675, 257/706, 257/707, 257/719
• US Class Current: 438/122
• CPC Class Codes: H01L 21/565 Moulds
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/451 with a principal constituent of the material being a metal or a metalloid, e.g. boron (B), silicon (Si), germanium (Ge), arsenic (As), antimony (Sb), tellurium (Te) and polonium (Po), and alloys thereof
• 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 23/3107 the device being completely enclosed
• CPC Class Codes: H01L 23/4334 Auxiliary members in encapsulations H01L23/49568 takes precedence
• 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 2924/01039 Yttrium [Y]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01087 Francium [Fr]
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 Diameter ranges

Abstract

A resin-sealed semiconductor device of the present invention includes: a lead frame having an island on which a semiconductor element is mounted and inner leads; and a heat spreader for diffusing heat generated in the semiconductor element, resin-sealing is made while the heat spreader, the island bottom and the inner leads are in face-contact with one another without an adhesive, and a part of the heat spreader is in contact with a part of the inner leads at the perimeter. The heat diffusion efficiency of the heat spreader is enhanced.

Claims

1. A semiconductor device comprising:

a semiconductor element;

a lead coupled to said semiconductor element;

an island on which said semiconductor element is mounted; and

a heat spreader being in direct contact with said island without using an adhesive, said heat spreader having a suspending portion at its corner in contact with said lead; and

a resin sealing said semiconductor element, said lead, said island, and said heat spreader including said suspending portion.

2. The device as claimed in claim 1, wherein said heat spreader is made of a metal plate.

3. The device as claimed in claim 1, wherein said heat spreader has a projection which is in contact with said the bottom surface of said island.

4. The device as claimed in claim 3, wherein said heat spreader has a plurality of slits and a plurality of dimples.

5. The device as claimed in claim 4, wherein said dimples are arranged at corners of said heat spreader.

6. The device as claimed in claim 5, wherein said slits are arranged between said dimples.

7. The device as claimed in claim 6, wherein said projection is arranged at a center of said heat spreader.

8. The device as claimed in claim 7, wherein the back surface of said heat spreader is not covered by said resin to be exposed by an air.

9. A semiconductor device comprising:

an island;

a semiconductor element formed on a top surface of said island;

a plurality of inner leads;

a suspending lead extending from a corner of said island;

a plurality of bonding wires coupled between said inner leads and said semiconductor element;

a heat spreader having a radiation portion and a suspending portion extending from a corner of said radiation portion, said radiation portion having a first surface being in direct contact with a bottom surface of said island, said suspending portion being in direct contact with said suspending lead;

a plurality of outer leads each coupled to the respective inner leads; and

a resin covering said island, said semiconductor element, inner leads, said suspending lead, said bonding wires, said heat spreader including said radiation portion and said suspending portion.

10. The device as claimed in claim 9, wherein a projection is formed at said first surface of said radiation portion so that said projection is in direct contact with said island.

11. The device as claimed in claim 10, wherein said radiation portion is larger than said island.

12. The device as claimed in claim 11, wherein said radiation portion has a plurality of slits and a plurality of dimples.

13. The device as claimed in claim 12, wherein said dimples are arranged at corners of said radiation potion.

14. The device as claimed in claim 13, wherein said slits are arranged between said dimples.

15. The device as claimed in claim 14, wherein a second surface of said radiation portion is not covered by said resin to be exposed by an air.

16. A method of manufacturing a semiconductor device, comprising:

applying a semiconductor element to the top of an island of a lead frame;

connecting inner leads on said lead frame to bonding pads on said semiconductor element by bonding wires;

putting a heat spreader in a lower mold;

placing said lead frame with the semiconductor element mounted thereto on said heat spreader so that a bottom surface of said lead frame is in direct contact with said heat spreader on said lower mold;

covering said lead frame and said heat spreader on said lower mold with an upper mold;

injecting a resin into an inner space defined by said lower and upper mold while perimeter portions of said lead frame and of said heat spreader is pressed by and held between said upper mold and said lower mold; and

cutting off suspending pins of said heat spreader after the resin is cured.

17. The method as claimed in claim 16, wherein said suspending pins of said heat spreader has a notch which is cut off.

18. The method as claimed in claim 17, wherein a seal measurement is larger than a mold line measurement and is smaller than a tie bar measurement.