Method of resiliently mounting an integrated circuit chip to enable conformal heat dissipation

• US 5,169,805 A
• Filed: 05/29/1991
• Issued: 12/08/1992
• Est. Priority Date: 01/29/1990
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Schwall, Robert E., Mok, Lawrence S., Tong, Ho-Ming
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Graybill, David E.
• Application Number:
  US07/706,637
• Time in Patent Office: 559 Days
• Field of Search: 437/214, 437/219, 437/224, 437/902, 29/855
• US Class Current: 438/117
• CPC Class Codes: H01L 2224/16225 the item being non-metallic, e.g. insulating substrate with or without metallisation
• CPC Class Codes: H01L 23/147 Semiconductor insulating substrates semiconductor conductive substrates H01L23/4926
• CPC Class Codes: H01L 23/16 Fillings or auxiliary members in containers or encapsulations, e.g. centering rings H01L23/42, H01L23/552 take precedence
• CPC Class Codes: H01L 23/3675 characterised by the shape of the housing
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• CPC Class Codes: Y10T 29/49146 with encapsulating, e.g., potting, etc.

Abstract

In integrated circuit packaging, chips are bonded to one side of an intermediate wafer that is resiliently mounted at the periphery with the entire other side of the intermediate wafer being maintained in conformal thermal transfer to external heat dissipation free of any solid connection.

Claims

1. The method of fabricating a conformal heat transfer semiconductor integrated circuit comprising the steps of:

positioning a spacer mold member which defines the periphery and thickness of a measured quantity of viscous thermal heat transfer material in contact with an interior surface of a heat dissipating structure,

filling said spacer mold member with said viscous heat transfer material,

removing said spacer mold,

positioning a resilient spacer member on said interior surface of said heat dissipating structure surrounding said viscous heat transfer material, and

assembling an intermediate wafer member supporting at least one integrated circuit chip and the combination of said viscous heat transfer material and said heat dissipating structure to a housing with the periphery of said wafer member in contact with said resilient spacer member.

2. The method of claim 1 including the step of forming an expansion groove in said interior surface of said heat dissipating structure.

3. The method of assembly of a planar integrated chip supporting member in viscous heat transfer material contact with a heat dissipating structure comprising in combination the steps of:

positioning a spacer mold member on a surface of said heat dissipating structure,

said spacer mold member having an interior opening shape and thickness that in combination define the area and volume of a selected measured quantity of said viscous heat transfer material,

filling said spacer mold member interior opening to said thickness whereby said selected measured quantity of said viscous heat transfer material is deposited,

positioning a resilient spacer member around said deposited measured quantity of said viscous heat transfer material, and,

assembling said planar integrated chip supporting member in contact with said

deposited heat transfer material with the periphery of said planar supporting member in contact with said resilient spacer member.

4. The method of claim 3 including the step of forming a heat transfer material expansion accommodating region in said heat dissipating structure.

5. In the assembly of a planar integrated chip supporting member, in viscous heat transfer material contact with a heat dissipating structure, the improved method comprising the steps of:

providing a planar selected measured quantity of viscous heat transfer material by filling a planar mold having an interior opening therein which opening defines the area and the thickness of said selected measured quantity of heat transfer material,

surrounding said planar measured quantity of viscous heat transfer material with a resilient spacer member, and,

positioning said planar integrated chip supporting member relative to said heat dissipating structure so that each is in contact with an opposite planar face of said planar selected measured quantity of said viscous heat transfer material.

6. The method of claim 5 including the step of forming a heat transfer material expansion accommodating region in said heat dissipating structure.

7. The improved method of forming a viscous heat transfer material contact between a planar integrated circuit chip supporting member and a heat dissipating structure comprising the steps of:

positioning on one of said planar integrated circuit chip supporting member and said heat dissipating structure a planar selected measured quantity of viscous heat transfer material by filling a planar mold having an interior opening therein which opening defines the area and the thickness of said selected measured quantity of heat transfer material,

surrounding said planar measured quantity of viscous thermal material with a resilient spacer member, and,

assembling said planar integrated circuit member in viscous thermal material contact with said heat dissipating structure by so positioning said integrated circuit member and said heat dissipating structure so that each is in contact with an opposite planar face of said planar selected measured quantity of said viscous heat transfer material.

8. The method of claim 7 including the step of forming a heat transfer material expansion accommodating region in said heat dissipating structure.