Composite heat sink structures

• US 9,761,508 B2
• Filed: 08/18/2015
• Issued: 09/12/2017
• Est. Priority Date: 11/18/2014
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Campbell, Levi A., David, Milnes P., Demetriou, Dustin W., Ellsworth, Jr., Michael J., Schmidt, Roger R., Simons, Robert E.
• Primary Examiner(s): Smith, Zandra
• Assistant Examiner(s): BOYLE, ABBIGALE A
• Application Number:
  US14/828,767
• Publication Number:
  US 20160136851A1
• Time in Patent Office: 756 Days
• CPC Class Codes: B29C 43/18 incorporating preformed parts or layers, e.g. compression moulding around inserts or for coating articles B29C43/206 takes precedence
• CPC Class Codes: B29C 43/203 Making multilayered articles
• CPC Class Codes: B29C 70/84 by moulding material on preformed parts to be joined joining plastic parts by moulding B29C65/70
• CPC Class Codes: B29C 70/88 characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced
• CPC Class Codes: B29K 2101/12 Thermoplastic materials
• CPC Class Codes: B29K 2705/00 Use of metals, their alloys or their compounds, for preformed parts, e.g. for inserts
• CPC Class Codes: B29L 2009/00 Layered products
• CPC Class Codes: B29L 2031/3406 Components, e.g. resistors
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 23/4006 with bolts or screws
• CPC Class Codes: H01L 23/427 Cooling by change of state, e.g. use of heat pipes by liquefied gas H01L23/445
• CPC Class Codes: H01L 23/473 by flowing liquids H01L23/4332, H01L23/4338 take precedence
• 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 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00
• CPC Class Codes: H05K 7/20254 Cold plates transferring heat from heat source to coolant
• CPC Class Codes: H05K 7/20436 Inner thermal coupling elements in heat dissipating housings, e.g. protrusions or depressions integrally formed in the housing
• CPC Class Codes: H05K 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures
• CPC Class Codes: H05K 7/20772 within server blades for removing heat from heat source

Abstract

Composite heat sink structures and methods of fabrication are provided, with the composite heat sink structures including: a thermally conductive base having a main heat transfer surface to couple to, for instance, at least one electronic component to be cooled; a compressible, continuous sealing member; and a sealing member retainer compressing the compressible, continuous sealing member against the thermally conductive base; and an in situ molded member. The in situ molded member is molded over and affixed to the thermally conductive base, and is molded over and secures in place the sealing member retainer. A coolant-carrying compartment resides between the thermally conductive base and the in situ molded member, and a coolant inlet and outlet are provided in fluid communication with the coolant-carrying compartment to facilitate liquid coolant flow through the compartment.

Claims

1. A method comprising:

forming a composite heat sink structure, the forming including;

obtaining a thermally conductive base, the thermally conductive base including a main heat transfer surface to couple to at least one component to be cooled;

placing a compressible, continuous sealing member on the thermally conductive base;

disposing a sealing member retainer over the compressible, continuous sealing member and compressing the compressible, continuous sealing member against the thermally conductive base; and

in situ forming a molded member over and affixed to the thermally conductive base, the in situ molded member being molded over and securing in place the sealing member retainer, wherein a coolant-carrying compartment resides between the thermally conductive base and the in situ molded member, and the compressible, continuous sealing member provides the composite heat sink structure with a fluid-tight seal.

2. The method of claim 1, wherein the compressing comprises using a mold fixture with multiple retaining pins to engage the sealing member retainer and compress the compressible, continuous sealing member during the in situ forming of the molded member.

3. The method of claim 1, wherein the forming the composite heat sink structure further comprises molding a depart material over the thermally conductive base to define a molded depart shape with, at least, a desired configuration for the coolant-carrying compartment, and wherein in situ forming the molded member comprises in situ forming the molded member over the sealing member retainer, the molded depart shape, and the thermally conductive base, and subsequently removing the molded depart shape, leaving, at least in part, the coolant-carrying compartment between the thermally conductive base and the in situ molded member.

4. The method of claim 1, wherein the forming the composite heat sink structure further comprises disposing a compartment cover on the thermally conductive base, the compartment cover being configured to define a desired configuration for the coolant-carrying compartment, between the compartment cover and the thermally conductive base, and wherein the in situ forming the molded member comprises in situ forming the molded member over the sealing member retainer, the compartment cover, and the thermally conductive base, and subsequently forming coolant inlet and outlet openings through the molded member and the compartment cover to facilitate liquid coolant flow through the coolant-carrying compartment.

5. The method of claim 1, wherein the thermally conductive base is fabricated of a metal or metal alloy, and the in situ molded member comprises a plastic.

6. The method of claim 1, wherein the in situ molded member comprises a first plastic, and the sealing member retainer comprises a second plastic, the first plastic and the second plastic being a same plastic or soluble plastics, and the in situ molded member is fused to the sealing member retainer.

7. The method of claim 1, wherein the thermally conductive base is fabricated of a metal or metal alloy, and the in situ molded member comprises a first plastic, and the sealing member retainer comprises a second plastic, the first plastic and the second plastic being a same plastic or soluble plastics, and the in situ forming of the molded member further fuses the molded member to the sealing member retainer.

8. The method of claim 1, wherein the in situ molded member molded over the thermally conductive base wraps around at least a portion of the thermally conductive base.

9. The method of claim 8, wherein the thermally conductive base includes at least one peripheral opening therein, and wherein the in situ molded member extends through the at least one peripheral opening to encircle the portion of the thermally conductive base.

10. The method of claim 1, wherein the in situ molded member comprises an in situ molded lid of the composite heat sink structure, the in situ molded lid comprising a coolant inlet and a coolant outlet.

11. The method of claim 10, further comprising providing a plurality of thermally conductive fins disposed within the coolant-carrying compartment to facilitate transfer of heat from the thermally conductive base to the liquid coolant flow through the coolant-carrying compartment, and wherein the coolant-carrying compartment further includes a coolant inlet manifold region in fluid communication with the coolant inlet, and a coolant outlet manifold region in fluid communication with the coolant outlet, wherein coolant within the coolant-carrying compartment flows from the coolant inlet manifold region, between the plurality of thermally conductive fins, to the coolant outlet manifold region.

12. The method of claim 10, further comprising providing a compartment cover, the coolant-carrying compartment being defined between the compartment cover and the thermally conductive base, and wherein the in situ molded member is further molded over and affixed to the compartment cover.

13. The method of claim 1, wherein the composite heat sink structure further comprises a manifold structure disposed over the thermally conductive base, the manifold structure including an upper manifold member and a lower manifold member, the lower manifold member comprising the in situ molded member.

14. The method of claim 13, wherein the manifold structure comprises a coolant inlet and a coolant outlet, and at least one inlet orifice in fluid communication with the coolant inlet and the coolant-carrying compartment, and at least one outlet orifice in fluid communication with the coolant-carrying compartment and the coolant outlet, wherein liquid coolant flows through the coolant inlet, the at least one inlet orifice, the coolant-carrying compartment, and the at least one outlet orifice, to the coolant outlet.

15. The method of claim 14, wherein the at least one inlet orifice comprises at least one inlet slot positioned over a central region of the coolant-carrying compartment, the at least one inlet slot facilitating the liquid coolant flow into the coolant-carrying compartment in the central region thereof.

16. The method of claim 1, wherein the main heat transfer surface resides at a first side of the thermally conductive base, and wherein the compressible, continuous sealing member is compressed against a second side of the thermally conductive base, the first side and the second side being opposite sides of the thermally conductive base.

17. The method of claim 16, wherein the sealing member retainer comprises a continuous sealing member retainer with a continuous groove, the compressible, continuous sealing member being covered by the continuous sealing member retainer and residing, at least in part, within the continuous groove in the continuous sealing member retainer.

18. The method of claim 16, wherein the thermally conductive base further comprises a continuous groove in the second side thereof, the compressible, continuous sealing member residing, at least in part, within the continuous groove in the second side of the thermally conductive base.