Interleaved-fin thermal connector

• US 6,138,748 A
• Filed: 11/14/1997
• Issued: 10/31/2000
• Est. Priority Date: 07/01/1996
• Status: Expired due to Term

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Digital Equipment Corporation (HP Inc.)
• Inventors: Fitch, John S., Hamburgen, William R., Eustace, Robert A.
• Primary Examiner(s): LEO, LEONARD R
• Application Number:
  US08/970,450
• Time in Patent Office: 1,082 Days
• Field of Search: 165/80.3, 165/185, 174/16.3, 257/721, 257/722, 361/704, 361/707
• US Class Current: 165/185
• CPC Class Codes: F28F 3/02 Elements or assemblies thereof with means for increasing heat-transfer area, e.g. with fins, with recesses, with corrugations F28F3/08 takes precedence
• CPC Class Codes: H01L 21/4882 Assembly of heatsink parts
• CPC Class Codes: H01L 2224/0401 Bonding areas specifically adapted for bump connectors, e.g. under bump metallisation [UBM]
• CPC Class Codes: H01L 2224/16 of an individual bump connector
• CPC Class Codes: H01L 2224/73253 Bump and layer connectors
• CPC Class Codes: H01L 23/367 Cooling facilitated by shape of device H01L23/38, H01L23/40, H01L23/42, H01L23/44, H01L23/46 take precedence
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 23/433 Auxiliary members in containers characterised by their shape, e.g. pistons
• 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 2924/01019 Potassium [K]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/09701 Low temperature co-fired ceramic [LTCC]
• CPC Class Codes: H01L 2924/15312 being a pin array, e.g. PGA
• CPC Class Codes: H01L 2924/16152 Cap comprising a cavity for hosting the device, e.g. U-shaped cap

Abstract

In order to provide a thermal coupling between a heat source and a heat sink, an interleaved-fin connector is provided. The connector comprises first and second substrates. The first substrate includes a first surface. A plurality of first channels are etched on the first surface to form a plurality of first fins and a first base. The first base can be thermally engaged with the heat source. The second substrate includes a second surface having a plurality of second channels etched therein. The second channels form a plurality of second fins and a second base. The second base can be thermally engaged with the heat sink. The first and second fins providing a thermally conductive path from the heat source to the heat sink when interleaved with each other.

Claims

1. An apparatus for thermally coupling a heat source to a heat sink, comprising:

a first substrate including a first surface having a plurality of first channels formed therein to form a plurality of first fins and a first base to thermally engage the heat source; and

a second substrate including a second surface having a plurality of second channels formed therein to form a plurality of second fins and a second base to thermally engage the heat sink, the first and second fins providing a thermally conductive path from the heat source to the heat sink when interleaved with each other;

wherein said first and second fins are cylindrical, and are concentric when interleaved with each other, and also wherein said substrates include cut-out portions for permitting limited relative rotational movement between said first and second fins when said first and second fins are interleaved with each other, within a relative rotational movement range that is limited by said cut-out portions.

2. The apparatus of claim 1 wherein the first and second substrates are made of a silicon crystal.

3. The apparatus of claim 2, wherein the silicon crystal is a single crystal silicon.

4. The apparatus of claim 3, wherein the single crystal silicon has an {110} orientation and at least one of the first and second channels coincide with a {111} plane of the single crystal silicon.

5. The apparatus of claim 1 wherein the first and second substrates are made of a polycrystal.

6. The apparatus of claim 1 further comprising:

a third substrate having opposing first and second side surfaces, a plurality of etched third channels formed in the first side surface to form a plurality of etched third fins, and a plurality of etched fourth channels formed in the second side surface to form a plurality of fourth fins, the third substrate to thermally the first and second substrates.

7. The apparatus of claim 6, wherein the third channels are angled with respect to the fourth channels in a non-orthogonal configuration.

8. The apparatus of claim 1, wherein at least one of the first and second channels is one of anisotropically etched and wet etched.

9. The apparatus of claim 1, wherein at least one of the first and second channels is dry etched.

10. The apparatus of claim 9 wherein the dry etching uses plasma.

12. The apparatus of claim 1, further comprising a plurality of third substrates, each third substrate having opposing first and second side surfaces, a plurality of etched third channels formed in the first side surface to form a plurality of third fins, and a plurality of etched fourth channels formed in the second side surface to form a plurality of fourth fins, the plurality of third substrates coupled together and thermally coupled to the first and second substrates to achieve at least six degrees of freedom.

13. The apparatus of claim 1, wherein the first and second channels are aligned along lattice cleavage planes of the respective first and second substrates.

14. The apparatus of claim 1, wherein the first and second channels are formed in a portion of the respective first and second substrates.

11. The apparatus of claim 20, wherein the dry etching as performed using reactive ions.

15. A thermal joint apparatus, comprising:

a first substrate including a plurality of first channels formed therein to form a plurality of first fins and a first base thermally engaged with a heat source;

a second substrate including a plurality of second channels formed therein to form a plurality of second fins and a second base for thermally engaging a heat sink; and

a third substrate including a plurality of third channels formed therein to form a plurality of third fins, some of said third fins being for interleaving with some of said first fins, others of said third fins being for interleaving with some of said second fins, each of said pluralities of first, second and third fins respectively including both concentric cylindrical fins and planar fins, so as to permit desired degrees of freedom of relative movement among said substrates to be achieved.

16. The apparatus of claim 15 wherein said others of said third fins and said some of said second fins are planar and parallel when interleaved with each other.

17. The apparatus of claim 15 further comprising a fourth substrate including a plurality of fourth fins including both cylindrical and planar fins, certain of said fourth fins are for being interleaved with remaining fins of one of said pluralities of first and second fins, and said first, second, third, and fourth fins are configured to permit said substrates to have six degrees of freedom of movement relative to each other.