Memory module assembly including heat sink attached to integrated circuits by adhesive

• US 7,365,985 B1
• Filed: 05/09/2006
• Issued: 04/29/2008
• Est. Priority Date: 09/29/2004
• Status: Expired due to Fees

• Current Assignee: Super Talent Technology, Corporation
• Original Assignee: Super Talent Electronics, Inc.
• Inventors: Ni, Jim
• Primary Examiner(s): DATSKOVSKIY, MICHAIL V
• Application Number:
  US11/382,467
• Time in Patent Office: 721 Days
• Field of Search: 361/688, 361/690, 361703-715, 361719-720, 361/737, 165/80.2, 165/80.3, 165/104.33, 165/185, 257706-708, 257712-713, 257717-722, 257/726, 257/727, 174/16.3, 174/16.1, 244/57, 244/58, 248/505, 248/510
• US Class Current: 361/715
• CPC Class Codes: H01L 23/3672 Foil-like cooling fins or heat sinks being part of lead-frames H01L23/49568
• CPC Class Codes: H01L 23/42 Fillings or auxiliary members in containers or encapsulations selected or arranged to facilitate heating or cooling
• CPC Class Codes: H01L 25/105 the devices being of a type provided for in group H01L27/00
• 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 7/20509 Multiple-component heat spreaders; Multi-component heat-conducting support plates; Multi-component non-closed heat-conducting structures

Abstract

A memory module assembly includes two-plate heat sink attached to one or more of the integrated circuits (e.g., memory devices) of a memory module PCBA by adhesive. The adhesive is either heat-activated or heat-cured. The adhesive is applied to either the memory devices or the heat-sink plates, and then compressed between the heat-sink plates and memory module using a fixture. The fixture is then passed through an oven to activate/cure the adhesive. The two heat sink plates are connected together to form a rigid frame.

Claims

1. A memory module assembly comprising:

a memory module printed circuit board assembly (PCBA) including;

a substrate having opposing first and second surfaces, a plurality of first wiring traces formed on at least one of the first and second surfaces, each of the first wiring traces being connected to an associated metal contact pad formed along a connector edge of the substrate; and

a first plurality of first integrated circuit (IC) devices and a second plurality of said first IC devices disposed on the first surface of the substrate such that upper surfaces of the first and second pluralities of first IC devices define a first plane that is parallel to the first surface of the substrate, and

a second IC device disposed on the first surface between the first and second pluralities of first IC devices, the second IC device having an upper surface defining a second plane that is parallel to the first surface of the substrate, wherein the first plane is located between the second plane and the first surface of the substrate;

a first heat-sink plate including first and second recessed regions respectively defining first and second planar underside surfaces, and a raised pocket region defining a third planar underside surface, the pocket region being disposed between the first and second recessed regions and

first and second adhesive portions, the first adhesive portion being sandwiched between the first planar underside surface and the upper surface of at least one of said first plurality of said first IC devices, and the second adhesive portion being sandwiched between the second planar underside surface and the upper surface of at least one of said second plurality of said first IC devices, whereby the first heat-sink plate is rigidly secured to the memory module by the first and second adhesive portions.

2. The memory module assembly of claim 1, wherein each of the first and second adhesive portions comprises a heat-activated adhesive material exhibiting a first, relatively low adherence when heated to a first, relatively high temperature, and exhibiting a second, relatively high adherence when subsequently cooled to a second, relatively low temperature.

3. The memory module assembly according to claim 2, wherein each of the first and second adhesive portions comprises a high thermal conductive adhesive film.

4. The memory module assembly according to claim 3, wherein the first heat-sink plate is secured to the memory module PCBA solely by the first and second adhesive portions.

5. The memory module assembly of claim 1,

substrate further comprises second wiring traces forming a bus,

wherein the first IC devices comprise dynamic random access memory (DRAM) devices connected to the bus, and

wherein the second IC device comprises an advanced memory buffer (AMB) device that is connected to each of the first and second pluralities of first IC devices by way of the bus, the AMB device also being connected to said plurality of first wiring traces.

6. The memory module assembly of claim 5, further comprising a thermal compound disposed between the upper surface of the AMB device and the third planar underside surface.

7. The memory module assembly of claim 6, wherein the thermal compound comprises one of a thermal paste and a silicone compound.

8. The memory module assembly according to claim 1, wherein the first heat-sink plate is mounted onto the memory module PCBA and substantially overlaps the first substrate surface in such a way that the first and second pluralities of said first IC devices and the second IC device are covered by the first heat-sink plate, and the connector edge is exposed such that the contact pads are exposed for pluggable insertion into a host socket.

9. The memory module assembly according to claim 1, wherein the memory module PCBA comprises a Fully-Buffered Dual In-line Memory Module (FB-DIMM).

10. The memory module assembly according to claim 1,

wherein the memory module further comprises a plurality of third IC devices mounted on the second surface of the substrate such that an upper surface of each of the plurality of third IC devices defines a third plane that is parallel to the second surface, and

wherein the memory module assembly further comprises a second heat-sink plate having a planar underside surface, and at least one third heat-activated adhesive portion sandwiched between the planar underside surface and the upper surface of at least one of the plurality of third IC devices such that the second heat-sink plate is rigidly secured to the memory module by said at least one third adhesive portion.

11. The memory module assembly according to claim 10, wherein the third IC devices comprise dynamic random access memory (DRAM) devices.

12. The memory module assembly according to claim 10, further comprising means for rigidly connecting the first heat-sink plate to the second heat-sink plate.

13. The memory module assembly according to claim 12, wherein said means comprises:

first support structures disposed on one or more edges of the first heat-sink plate and extending perpendicular to the first plane, and

second support structures disposed on one or more edges of the second heat-sink plate and extending perpendicular to the first plane,

wherein each first support structure abuts a corresponding second support structure such that the first heat-sink plate is prevented from moving toward the second heat-sink plate.

14. The memory module assembly according to claim 12, wherein said means comprises:

a first engagement structure disposed on an edge of the first heat-sink plate and extending perpendicular to the first plane, and

a second engagement structure disposed on an edge of the second heat-sink plate and extending perpendicular to the first plane,

wherein the first engagement structure is operably engaged to the second engagement structure such that the first heat-sink plate is prevented from moving away from the second heat-sink plate.

15. The memory module assembly according to claim 12, wherein said first engagement structure is disposed on a long edge of the first heat-sink plate, and wherein said second engagement structure is disposed on a long edge of the second heat-sink plate.

16. The memory module assembly according to claim 12, wherein said first engagement structure is disposed on a short edge of the first heat-sink plate, and wherein said second engagement structure is disposed on a short edge of the second heat-sink plate.

17. The memory module assembly according to claim 12, wherein at least one of the first engagement structure and the second engagement structure comprises a latch.

18. The memory module assembly according to claim 12, wherein the first engagement structure and the second engagement structure comprise a self-engaging, interlocking structure.

19. The memory module assembly according to claim 12, wherein at lease one of the first heat-sink plate and the second heat-sink plate comprise ridged fins.

20. A memory module assembly comprising:

a memory module printed circuit board assembly (PCBA) including;

a substrate having opposing first and second surfaces, a plurality of wiring traces formed on the first and second surfaces, at least some of the wiring traces being connected to metal contact pads formed along a connector edge of the substrate, and

a plurality of first integrated circuit (IC) devices mounted on the first surface of the substrate such that an upper surface of each of the plurality of first IC devices defines a first plane that is parallel to the first surface of the substrate, and

a plurality of second IC devices mounted on the second surface of the substrate such that an upper surface of each of the plurality of second IC devices defines a second plane that is parallel to the second surface;

a first heat-sink plate having a first planar underside surface;

a second heat-sink plate having a second planar underside surface;

a plurality of heat-activated adhesive portions including a first adhesive portion sandwiched between the first planar underside surface of the first heat-sink plate and the upper surface of an associated IC device of said plurality of first IC devices such that the first heat-sink plate is rigidly secured to the memory module by the plurality of first adhesive portions, and a second adhesive portion sandwiched between the second planar underside surface of the second heat-sink plate and the upper surface of an associated IC device of said plurality of second IC devices such that the second heat-sink plate is rigidly secured to the memory module by the plurality of second adhesive portions; and

means for rigidly connecting the first heat-sink plate to the second heat-sink plate.

21. The memory module assembly according to claim 20, wherein said means comprises:

first support structures disposed on one or more edges of the first heat-sink plate and extending parallel to the first plane, and

second support structures disposed on one or more edges of the second heat-sink plate and extending parallel to the first plane,

wherein each first support structure abuts a corresponding second support structure such that the first heat-sink plate is prevented from moving toward the second heat-sink plate.

22. The memory module assembly according to claim 20, wherein said means comprises:

a first engagement structure disposed on an edge of the first heat-sink plate and extending perpendicular to the first plane, and

a second engagement structure disposed on an edge of the second heat-sink plate and extending perpendicular to the first plane,

wherein the first engagement structure is operably engaged to the second engagement structure such that the first heat-sink plate is prevented from moving away from the second heat-sink plate.

23. The memory module assembly according to claim 22, wherein said first engagement structure is disposed on a long edge of the first heat-sink plate, and wherein said second engagement structure is disposed on a long edge of the second heat-sink plate.

25. The memory module assembly according to claim 22, wherein at least one of the first engagement structure and the second engagement structure comprises a latch.

26. The memory module assembly according to claim 22, wherein at the first engagement structure and the second engagement structure comprise a self-engaging, interlocking structure.

27. The memory module assembly according to claim 20, wherein at lease one of the first heat-sink plate and the second heat-sink plate comprise ridged fins.

24. A memory module assembly comprising:

a memory module printed circuit board assembly (PCBA) including;

a substrate having opposing first and second surfaces, a plurality of wiring traces formed on the first and second surfaces, at least some of the wiring traces being connected to metal contact pads formed along a connector edge of the substrate, and

a plurality of first integrated circuit (IC) devices mounted on the first surface of the substrate such that an upper surface of each of the plurality of first IC devices defines a first plane that is parallel to the first surface of the substrate, and

a plurality of second IC devices mounted on the second surface of the substrate such that an upper surface of each of the plurality of second IC devices defines a second plane that is parallel to the second surface;

a first heat-sink plate having a first planar underside surface;

a second heat-sink plate having a second planar underside surface;

a plurality of heat-activated adhesive portions including a first adhesive portion sandwiched between the first planar underside surface of the first heat-sink plate and the upper surface of an associated IC device of said plurality of first IC devices such that the first heat-sink plate is rigidly secured to the memory module by the plurality of first adhesive portions, and a second adhesive portion sandwiched between the second planar underside surface of the second heat-sink plate and the upper surface of an associated IC device of said plurality of second IC devices such that the second heat-sink plate is rigidly secured to the memory module by the plurality of second adhesive portions; and

means for rigidly connecting the first heat-sink plate to the second heat-sink plate, wherein said means comprises;

a first engagement structure disposed on an edge of the first heat-sink plate and extending perpendicular to the first plane, and

a second engagement structure disposed on an edge of the second heat-sink plate and extending perpendicular to the first plane,

wherein the first engagement structure is operably engaged to the second engagement structure such that the first heat-sink plate is prevented from moving away from the second heat-sink plate, and

wherein said first engagement structure is disposed on a short edge of the first heat-sink plate, and wherein said second engagement structure is disposed on a short edge of the second heat-sink plate.