Electronic package with improved thermal properties

• US 5,650,663 A
• Filed: 07/03/1995
• Issued: 07/22/1997
• Est. Priority Date: 07/03/1995
• Status: Expired due to Fees

• Current Assignee: Advanced Technology Incubator Incorporated
• Original Assignee: OLIN Corporation
• Inventors: Parthasarathi, Arvind
• Primary Examiner(s): Saadat, Mahshid D.
• Assistant Examiner(s): ARROYO, TERESA M
• Application Number:
  US08/497,836
• Time in Patent Office: 750 Days
• Field of Search: 257/787, 257/675, 257/710, 257/706, 257/70, 257/779, 257/796, 174/52.4
• US Class Current: 257/706
• CPC Class Codes: H01L 2224/05599 Material
• CPC Class Codes: H01L 2224/45015 being circular
• CPC Class Codes: H01L 2224/45099 Material
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/3736 Metallic materials H01L23/3732, H01L23/3733, H01L23/3735, H01L23/3737, H01L23/3738 take precedence
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• 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 2924/01046 Palladium [Pd]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01322 Eutectic Alloys, i.e. obtained by a liquid transforming into two solid phases
• CPC Class Codes: H01L 2924/10253 Silicon [Si]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 2924/207 : Diameter ranges

Abstract

An electronic package having improved thermal performance. In the case of a plastic package, the inner ends of the leads of the lead frame are attached to a heat slug by a high thermal conductivity material such as solder or a polymeric material. In the case of a metal package, the inner ends of the leads of the leadframe are attached to the metal base component by a high thermal conductivity material.

Claims

1. An electronic package comprising:

a. a heat spreading substrate,

b. an electronic device attached to said heat spreading substrate,

c. a lead frame having a plurality of leads having their inner ends wire bonded to said electronic device and their outer ends extending from said package, and

d. a high thermal conductivity material selected from the group consisting of solders and conductive polymers connecting said inner ends of each said lead to the heat spreading substrate.

2. The electronic package of claim 1 wherein said heat spreading substrate, said electronic device and said inner ends of said leads are encased in a plastic body.

3. The electronic package of claim 1 wherein said high thermal conductivity material is solder.

4. The electronic package of claim 3 wherein said solder attaching said inner ends of said leads to said substrate has a melting point of about 230°

C. or above.

5. The electronic package of claim 3 wherein said solder attaching said inner ends of said leads to said substrate has a melting point of from about 250°

C. to about 300°

C.

6. The electronic package of claim 1 wherein said high thermal conductivity material is a high thermal conductivity polymeric material.

7. The electronic package of claim 1 wherein said electronic device, the inner ends of said leads and said heat spreading substrate are encased in a plastic body.

8. The electronic package of claim 1 wherein said electronic device, the inner ends of said leads and the side walls and top surface of said heat spreading substrate are encased in a plastic body, with the bottom surface of said substrate exposed.

9. The electronic package of claim 1 wherein said heat spreading substrate is fabricated from aluminum, copper, or alloys thereof, and said lead frame is fabricated from copper, copper alloys or iron-nickel alloys.

10. The electronic package of claim 9 wherein said heat spreading substrate has an electrically insulating coating thereon.

11. An electronic package comprising:

a. a metal cover component,

b. a metal base component, said base component and said cover component defining a cavity,

c. an electronic component attached to said base component and positioned in said cavity,

d. a lead frame disposed between and adapted to be bonded to said cover and base components and having inner lead ends, and

e. a high thermal conductivity material selected from the group consisting of solders and conductive polymers connecting said inner lead ends to said base component.

12. The electronic package of claim 11 wherein said high thermal conductivity material is solder.

13. The electronic package of claim 12 wherein said solder attaching said inner lead ends to said base component has a melting point of about 230°

C. or above.

14. The electronic package of claim 12 wherein said solder attaching said inner ends of said leads to said base component has a melting point of from about 250°

C. to about 300°

C.

15. The electronic package of claim 11 wherein said high thermal conductivity material is a high thermal conductivity polymeric material.

16. The electronic package of claim 11 wherein said cover component and said base component are fabricated from aluminum or aluminum alloys and said lead frame is fabricated from copper, copper alloys or iron-nickel alloys.

17. The electronic package of claim 16 wherein at least a portion of the surface of the base component and cover component has an anodization layer thereon.