Graphite composites for electronic packaging

• US 5,650,592 A
• Filed: 04/05/1993
• Issued: 07/22/1997
• Est. Priority Date: 04/05/1993
• Status: Expired due to Fees

• Current Assignee: HCC Aegis, Inc. (Ametek Incorporated)
• Original Assignee: OLIN Corporation
• Inventors: Cheskis, Harvey, Mahulikar, Deepak
• Primary Examiner(s): Ledynh, Bot L.
• Application Number:
  US08/042,913
• Time in Patent Office: 1,569 Days
• Field of Search: 174/52.4, 174/52.1-52.3, 257/704, 257/702, 257/709, 428/408, 361/746, 361/805, 361/820
• US Class Current: 174/540
• 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 2224/48091 Arched
• CPC Class Codes: H01L 2224/73265 Layer and wire connectors
• CPC Class Codes: H01L 2224/85399 Material
• CPC Class Codes: H01L 23/06 characterised by the material of the container or its electrical properties
• CPC Class Codes: H01L 23/142 Metallic substrates having insulating layers
• CPC Class Codes: H01L 23/3733 having a heterogeneous or anisotropic structure, e.g. powder or fibres in a matrix, wire mesh, porous structures H01L23/3732, H01L23/3737 take 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 2924/00014 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 2924/01004 Beryllium [Be]
• CPC Class Codes: H01L 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/0102 Calcium [Ca]
• CPC Class Codes: H01L 2924/01078 Platinum [Pt]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/14 Integrated circuits
• CPC Class Codes: H01L 2924/15153 the die mounting substrate comprising a recess for hosting the device
• CPC Class Codes: H01L 2924/15165 : Monolayer substrate
• CPC Class Codes: H01L 2924/16152 : Cap comprising a cavity for hosting the device, e.g. U-shaped cap
• CPC Class Codes: H01L 2924/167 : 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 2924/16787 : Ceramics, e.g. crystalline carbides, nitrides or oxides
• CPC Class Codes: H01L 2924/1679 : with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2924/207 : Diameter ranges

Abstract

There is provided a component for use in electronic packaging. The component is a composite having a graphite matrix which is infiltrated with a metal or a metal alloy and the external surfaces of the composite then coated with a metallic layer to provide environmental and mechanical protection. The packaging components are lightweight, have a coefficient of thermal expansion close to that of a silicon based integrated circuit device and further, have a high coefficient of thermal conductivity.

Claims

1. An electronic package, comprising:

a base formed from a metal infiltrated graphite composite, said base being hermetic and free of open pores and coated with a metallic layer;

a cover;

a leadframe disposed between said base and said cover; and

a dielectric sealant bonding said base to said cover with said leadframe disposed therebetween.

2. The electronic package of claim 1 wherein said metallic layer is solderable.

3. The electronic package of claim 2 wherein said metallic layer is selected from the group consisting of gold, silver, nickel and alloys thereof.

4. The electronic package of claim 3 wherein said metallic layer is gold having a thickness of from about 2 to about 20 microns.

5. The electronic package of claim 1 wherein said metallic layer is capable of forming a refractory oxide.

6. The electronic package of claim 5 wherein said metallic layer is selected from the group consisting of nickel, aluminum and alloys thereof.

7. The electronic package of claim 6 wherein said metallic layer is nickel having a thickness of from about 5 to about 30 microns.

8. The electronic package of claim 7 wherein said dielectric sealant is selected from the group consisting of polymer adhesives and sealing glasses.

9. The electronic package of claim 8 wherein said sealant is a thermosetting epoxy.

10. The electronic package of claim 8 wherein said cover is selected to have a coefficient of thermal expansion approximately equal to the coefficient of thermal expansion of said base.

11. The electronic package of claim 10 wherein said cover is selected to be alumina.

13. The electronic package of claim 1 wherein said base is formed from an aluminum or an aluminum alloy infiltrated graphite composite.

12. A substrate for a multi-chip module, comprising:

a base formed from a metal infiltrated graphite composite, said base being hermetic and free of open pores and coated with a metallic layer;

a nonconductive layer having first and second sides and at least one aperture, said first side bonded to said base;

a pattern of circuit traces formed on said second side of said nonconductive layer; and

one or more integrated circuit devices bonded to said base and extending through said at least one aperture and electrically interconnected to said pattern of circuit traces.