Thermally Conductive Dielectric Interface

• US 20140374071A1
• Filed: 06/20/2014
• Published: 12/25/2014
• Est. Priority Date: 06/25/2013
• Status: Active Grant

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: Berquist Company The (Henkel AG & Co KGaA)
• Inventors: Timmerman, John, Schmitz, Jeremy J., Hammond, Jeremy L.
• Granted Patent: US 9,693,481 B2
• Time in Patent Office: Days
• US Class Current: 165/133
• CPC Class Codes: H01L 2224/2908 being stacked
• CPC Class Codes: H01L 2224/2929 with a principal constituent of the material being a polymer, e.g. polyester, phenolic based polymer, epoxy
• CPC Class Codes: H01L 2224/293 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 2224/29386 with a principal constituent of the material being a non metallic, non metalloid inorganic material
• CPC Class Codes: H01L 2224/32245 the item being metallic
• CPC Class Codes: H01L 23/3735 Laminates or multilayers, e.g. direct bond copper ceramic substrates
• CPC Class Codes: H01L 23/3737 Organic materials with or without a thermoconductive filler
• 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: H01L 24/29 of an individual layer connector
• CPC Class Codes: H01L 2924/0665 Epoxy resin
• CPC Class Codes: H05K 7/2039 characterised by the heat transfer by conduction from the heat generating element to a dissipating body arrangements for increasing/decreasing heat-transfer, e.g. fins details, F28F13/00
• CPC Class Codes: Y10T 29/4935 Heat exchanger or boiler making

Abstract

A thermally conductive dielectric interface includes a relatively hard polymer base, and a polymer upcoat disposed at first and second sides of the base. The upcoat has an intermediate condition that is relatively soft and facilitates thermal joints with respective components of an electronic assembly. Curing the upcoat layer to a finished condition solidifies such thermal joints.

Claims

1. A thermally conductive dielectric interface, comprising:

a base having first and second sides substantially parallel to a base plane, and exhibiting a compressive modulus of at least 10⁵ Pa, said base comprising a first silicone polymer preparation; and

an upcoat disposed at said first and second sides of said base, said upcoat exhibiting a compressive modulus of less than 10⁴ Pa, and comprising a second silicone polymer preparation, wherein a thickness of said interface is defined along an axis perpendicular to said base plane and extends through said upcoat and said base, and said interface exhibiting a voltage breakdown value of at least 3 kV and a thermal conductivity of at least 0.5 W/m*K through said thickness.

2. A thermally conductive dielectric interface as in claim 1, including particulate filler dispersed in each of said first and second silicone polymer preparations.

3. A thermally conductive dielectric interface as in claim 1 wherein said first silicone polymer preparation is more fully cured than said second silicone polymer preparation.

4. A thermally conductive dielectric interface as in claim 1 wherein said interface exhibits an electrical resistance of at least 10¹⁰ Ω

*m through said thickness.

5. A thermally conductive dielectric interface as in claim 1 wherein said base is between 0.1-0.25 mm along said axis.

6. A thermally conductive dielectric interface as in claim 5 wherein said upcoat is between 0.05-0.30 mm along said axis.

7. A method for mounting a heat sink to a heat-generating component, said method comprising securing the thermally conductive dielectric interface of claim 1 between said heat sink and said heat-generating component.

8. A method as in claim 7 wherein said upcoat bonds said interface to said heat sink and said heat-generating component.

9. A method as in claim 8, including, subsequent to bonding said interface to said heat sink and said heat-generating component, curing said upcoat to an extent at which said upcoat exhibits a compressive modulus of greater than 10⁴ Pa.

10. A method as in claim 9 wherein said curing includes initiating a cross-linking reaction in said second silicone polymer preparation

11. A thermally conductive dielectric interface, comprising:

a core having first and second opposed surfaces substantially parallel to a core plane, and defining respective first and second sides of said interface;

a base layer with an inner surface applied to each of said first and second surfaces of said core, said base layer comprising thermally conductive particles dispersed in a first polymer preparation, wherein said base layer exhibits a compressive modulus of at least 10⁵ Pa; and

an upcoat layer applied to an outer surface of said base layer at both said first and second sides of said interface, said upcoat layer comprising thermally conductive particles dispersed in a second polymer preparation, wherein said upcoat layer exhibits a compressive modulus of less than 10⁴ Pa,

wherein a thickness of said thermally conductive interface is defined along an axis perpendicular to said core plane and extends through said upcoat layer, said base layer, and said core, and said interface exhibits a thermal conductivity of at least 0.5 W/m*K, and an electrical resistance of at least 10¹⁰ Ω

*m through said thickness.

12. A thermally conductive dielectric interface as in claim 11, wherein said thermally conductive particles are metal or ceramic.

13. A thermally conductive interface as in claim 11 wherein said core comprises a fiberglass film.

14. A thermally conductive interface as in claim 11 wherein said first and second polymer preparations include a silicone polymer matrix.