Heat Dissipation for Substrate Assemblies

• US 20150245533A1
• Filed: 05/12/2014
• Published: 08/27/2015
• Est. Priority Date: 02/27/2014
• Status: Active Grant

• Current Assignee: SanDisk Technologies LLC (Western Digital Corporation)
• Original Assignee: SanDisk Enterprise IP LLC (Western Digital Corporation)
• Inventors: Dean, David, Ellis, Robert W., Wright, David A.
• Granted Patent: US 9,497,889 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H05K 1/0203 Cooling of mounted components H05K1/0272 takes precedence
• CPC Class Codes: H05K 1/0207 using internal conductor planes parallel to the surface for thermal conduction, e.g. power planes
• CPC Class Codes: H05K 1/0254 High voltage adaptations; Electrical insulation details; Overvoltage or electrostatic discharge protection electrostatic discharge protection for electric apparatus in general H05K9/0067, H05K9/0079; Arrangements for regulating voltages or for using plural voltages
• CPC Class Codes: H05K 1/0259 Electrostatic discharge [ESD] protection
• CPC Class Codes: H05K 1/181 associated with surface mounted components
• CPC Class Codes: H05K 2201/066 Heatsink mounted on the surface of the PCB heatsink inserted in the PCB H05K2201/10416
• CPC Class Codes: H05K 2201/10159 Memory
• CPC Class Codes: H05K 7/1489 characterized by the mounting of blades therein, e.g. brackets, rails, trays H05K7/1491 takes precedence
• 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: H05K 7/205 Heat-dissipating body thermally connected to heat generating element via thermal paths through printed circuit board [PCB] details of PCBs relating to heat transfer H05K1/0201
• CPC Class Codes: H05K 7/20709 for server racks or cabinets; for data centers, e.g. 19-inch computer racks

Abstract

Various embodiments described herein include systems, methods and/or devices used to dissipate heat generated by electronic components in an electronic system (e.g., a memory system that includes closely spaced memory modules). In one aspect, an electronic system includes a substrate, at least one electronic component, and a heat sink. The at least one electronic component is mechanically coupled to the substrate and thermally coupled to a ground plane of the substrate, such that heat generated by the at least one electronic component is dissipated at least partially to the ground plane of the substrate. The heat sink is mechanically coupled to an edge of the substrate, and thermally coupled to the ground plane of the substrate to at least partially dissipate the heat generated by the at least one electronic component. In some embodiments, the heat sink further includes an attachment structure, a tab and a plurality of heat dissipaters.

Claims

1. An electronic system, comprising:

a substrate comprising a ground plane;

at least one electronic component mechanically coupled to the substrate and thermally coupled to the ground plane, such that heat generated by the at least one electronic component is dissipated at least partially to the ground plane of the substrate; and

a heat sink mechanically coupled to an edge of the substrate, the heat sink being thermally coupled to the ground plane of the substrate to at least partially dissipate the heat generated by the at least one electronic component.

2. The electronic system of claim 1, wherein the heat sink further comprises:

an attachment structure that is configured to mechanically couple to the edge of the substrate and thermally couple to the ground plane of the substrate;

a tab that has a width substantially equal to a thickness of the substrate, wherein the tab is configured to extend from the attachment structure to mate with a card guide structure in an assembly rack; and

a plurality of heat dissipaters that are configured to increase the heat dissipation area of the heat sink.

3. The electronic system of claim 2, wherein the plurality of heat dissipaters comprises a first set of fins that are substantially parallel to each other and a second set of fins that are substantially parallel to each other, and the first set of fins and the second set of fins are oriented differently according to a direction of an airflow in order to distribute the airflow substantially evenly across the substrate.

4. The electronic system of claim 2, wherein at least one heat dissipater of the plurality of heat dissipaters extends from the heat sink where the edge of the substrate to which the heat sink is attached to an area above a central region of the substrate, and overlaps with a part of the substrate.

5. The electronic system of claim 1, wherein the heat sink further comprises an attachment structure that is configured to allow the edge of the substrate to mechanically lock into the attachment structure.

6. The electronic system of claim 1, wherein the heat sink comprises a first heat sink that is mechanically coupled via a first attachment structure to a first edge of the substrate, the electronic system further comprising:

a second heat sink mechanically coupled via a second attachment structure to a second edge of the substrate that is opposite to the first edge of the substrate, the second heat sink being also thermally coupled to the ground plane to at least partially dissipate the heat generated by the at least one electronic component from the second edge of the substrate.

7. The electronic system of claim 6, wherein each of the first heat sink and the second heat sink includes a respective tab that has a respective width substantially equal to a thickness of the substrate, and the tabs of the first and second heat sinks are configured to extend from the first attachment structure and second attachment structure, respectively, to mate with a card guide structure in an assembly rack at both edges of the substrate.

8. The electronic system of claim 1, wherein the heat sink is electrically coupled to the ground plane via an electrostatic discharge (ESD) protection circuit.

9. The electronic system of claim 1, wherein thermally conductive adhesive is applied to thermally couple and electrically insulate the heat sink and the substrate, and the thermally conductive adhesive has substantially low thermal impedance and substantially high electrical resistance.

10. The electronic system of claim 1, wherein the substrate comprises a first substrate, and the electronic system comprises a plurality of substrates including the first substrate, each substrate in a subset of the plurality of substrates being thermally coupled to a respective heat sink at an edge of the respective substrate to dissipate heat generated by at least one respective electronic component mounted on the respective substrate, each substrate of the subset of substrates being assembled on an assembly rack via a respective tab on the respective heat sink and oriented substantially in parallel.

11. A heat sink for dissipating heat, comprising:

an attachment structure that is configured to mechanically couple to an edge of a substrate and thermally couple to a ground plan of the substrate, wherein the substrate includes the ground plane and at least one electronic component, and the at least one electronic component is mechanically coupled to the substrate and thermally coupled to the ground plane, such that heat generated by the at least one electronic component is at least partially dissipated to the ground plane of the substrate and further to the attachment structure of the heat sink;

a tab that has a width substantially equal to a thickness of the substrate, wherein the tab is configured to extend from the attachment structure to mate with a card guide structure in an assembly rack; and

a plurality of heat dissipaters that are configured to increase the heat dissipation area of the heat sink and at least partially dissipate the heat generated by the at least one electronic component.

12. The heat sink of claim 11, wherein the attachment structure further comprises a friction lock attachment slot configured to mechanically lock a substrate edge in accordance with a narrowed slot neck.

13. The heat sink of claim 11, wherein the attachment structure further comprises a first thermal via whose location matches that of a second thermal via on the corresponding substrate edge, and in accordance with integration of the heat sink and the substrate, the first and second thermal vias are aligned to form a heat pathway through the integrated heat sink and substrate.

14. The heat sink of claim 11, wherein the plurality of heat dissipaters comprises a first set of fins that are substantially parallel to each other and a second set of fins that are substantially parallel to each other, and the first set of fins and the second set of fins are oriented differently according to a direction of an airflow in order to distribute the airflow substantially evenly across the substrate.

15. The heat sink of claim 11, wherein at least one heat dissipater of the plurality of heat dissipaters extends from the edge of the substrate to which the attachment structure is mechanically coupled to an area above a central region of the substrate, and substantially overlaps with a part of the substrate.

16. A heat dissipation method, comprising:

providing an attachment structure and a tab of a heat sink according to geometries of an edge of a substrate, the tab having a width substantially equal to a thickness of the substrate and configured to extend from the attachment structure to mate with a card guide structure on an assembly rack;

providing a plurality of heat dissipaters on the heat sink, such that a heat dissipation area of the heat sink is increased for at least partially dissipating heat absorbed by the heat sink; and

mechanically coupling the heat sink at the edge of the substrate via the attachment structure to form an electronic system, wherein the attachment structure is mechanically coupled to the edge of the substrate and thermally coupled to a ground plane of the substrate, and wherein at least one electronic component is mechanically coupled on the substrate and thermally coupled to a ground plane of the substrate, and heat generated by the at least one electronic component is dissipated at least partially to the ground plane of the substrate and further to the heat sink including the attachment structure, the tab and the plurality of heat dissipaters.

17. The heat dissipation method of claim 16, further comprising integrating the electronic system that includes the heat sink and the substrate onto an assembly rack of an electronic assembly,

18. The heat dissipation method of claim 16, wherein the heat sink comprises a first heat sink that is mechanically coupled to a first edge of the substrate, the electronic system further comprising:

a second heat sink mechanically coupled to a second edge of the substrate that is opposite to the first edge of the substrate, the second heat sink being also thermally coupled to the ground plane to at least partially dissipate the heat generated by the at least one electronic component.

19. The heat dissipation method of claim 16, wherein thermally conductive adhesive is applied to thermally couple and electrically insulate the heat sink and the substrate, and the thermally conductive adhesive has substantially low thermal impedance and substantially high electrical resistance.

20. The heat dissipation method of claim 16, wherein the substrate comprises a first substrate, and the electronic system comprises a plurality of substrates including the first substrate, each substrate in a subset of the plurality of substrates being thermally coupled to a respective heat sink at an edge of the respective substrate to dissipate heat generated by at least one respective electronic component mounted on the respective substrate, each substrate of the subset of substrates being assembled on an assembly rack via a respective tab on the respective heat sink and oriented substantially in parallel.