Thermally Dissipative Enclosure Having Shock Absorbing Properties

• US 20100142154A1
• Filed: 12/04/2008
• Published: 06/10/2010
• Est. Priority Date: 12/04/2008
• Status: Abandoned Application

• Current Assignee: Microvision, Inc.
• Original Assignee: Microvision, Inc.
• Inventors: Collet, Roeland, Whalen, Randall J., Byeman, Thomas, Luanava, Selso, Hegland, Joel E.
• Application Number:
  US12/328,478
• Publication Number:
  US 20100142154A1
• Time in Patent Office: Days
• US Class Current: 361/714
• CPC Class Codes: G03B 21/16 Cooling; Preventing overheating
• CPC Class Codes: H05K 7/20454 with a conformable or flexible structure compensating for irregularities, e.g. cushion bags, thermal paste

Abstract

A thermally dissipative housing (200) includes a rigid housing (203) and a compliant heat spreader (215). The compliant heat spreader (215) is thermally coupled to a heat-generating component (201) disposed within the thermally dissipative housing (200). The compliant heat spreader (215) removes heat from the heat-generating component (201) and transfers it along an interior surface of the rigid housing (203) by passing along an interior (209) of the rigid housing (203) across at least a portion of the interior surface area (211) of the rigid housing (203). The compliant heat spreader (215) transfers heat to the surface of the rigid housing (203) without substantially interfering with the shock absorbing properties of the rigid housing (203).

Claims

1. A thermally dissipative housing for heat generating electronic components, the thermally dissipative housing comprising:

a rigid housing having an interior and an exterior, the interior having an interior surface area;

a printed circuit board disposed within the rigid housing, the printed circuit board comprising one or more of the heat generating electronic components; and

a compliant heat spreader thermally coupled to the one or more of the heat generating electronic components, the compliant heat spreader passing along the interior of the rigid housing across at least twenty-five percent of the interior surface area.

2. The thermally dissipative housing of claim 1, wherein the compliant heat spreader is configured to be in thermal contact with the rigid housing for passively cooling the rigid housing.

3. The thermally dissipative housing of claim 2, wherein the compliant heat spreader is adhesively affixed to at least a portion of the rigid housing.

4. The thermally dissipative housing of claim 2, wherein the rigid housing comprises a thermoplastic material.

5. The thermally dissipative housing of claim 4, wherein the thermoplastic material comprises one of polycarbonate, ABS, or combinations thereof.

6. The thermally dissipative housing of claim 4, wherein the rigid housing has a thermal conductivity of between 0.1 watts per meter Kelvin and 1.0 watts per meter Kelvin.

7. The thermally dissipative housing of claim 4, wherein the compliant heat spreader comprises an insert molded feature of the rigid housing.

8. The thermally dissipative housing of claim 4, wherein the rigid housing is configured without metal exposed along the exterior of the rigid housing and without airflow perforations.

9. The thermally dissipative housing of claim 8, wherein the rigid housing comprises an upper housing sealed to a lower housing.

10. The thermally dissipative housing of claim 1, wherein the compliant heat spreader passes across at least fifty percent of the interior surface area.

11. The thermally dissipative housing of claim 1, wherein the compliant heat spreader comprises one of flexible copper sheets, flexible aluminum sheets, or flexible graphite sheets.

12. The thermally dissipative housing of claim 11, wherein the compliant heat spreader comprises a flexible graphite sheet having a thickness of between 100 micrometers and 500 micrometers.

13. The thermally dissipative housing of claim 12, wherein the compliant heat spreader comprises a plurality of compliant heat spreader members, each of the plurality of compliant heat spreader members overlapping and affixed to at least a portion of another of the plurality of compliant heat spreader members.

14. The thermally dissipative housing of claim 1, wherein the compliant heat spreader is encapsulated in an electrically insulating material.

15. The thermally dissipative housing of claim 1, wherein the heat generating electronic components comprise an image projection system, wherein the thermally dissipative housing is configured such that the image projection system is subjected to a shock force of less than 3000 G when dropped from seven feet to a concrete surface.

16. The thermally dissipative housing of claim 15, wherein the rigid housing comprises a thermoplastic material having a thickness of between one and two millimeters, further wherein the compliant heat spreader comprises a flexible layer of graphite having a thickness of between 100 and 500 micrometers.

17. The thermally dissipative housing of claim 1, wherein the thermally dissipative housing has an emissivity of between 0.6 and 1.0.

18. The thermally dissipative housing of claim 1, further comprising a compressible non-electrically conductive material having a loop of compliant thermally conductive material disposed about the compressible non-electrically conductive material disposed between the one or more of the heat generating electronic components and the rigid housing.

19. An image production device, comprising:

a projector mounted within the image production device;

a compliant thermally conductive material thermally coupled to the projector; and

a housing having a rigidity greater than the compliant thermally conductive material and a thermal conductivity less than the compliant thermally conductive material;

wherein the substrate is fixed relative to the housing and the compliant thermally conductive material is thermally coupled to the housing; and

wherein the compliant thermally conductive material passes along an interior of the housing across at least a portion of an interior of the housing.

20. The image production device of claim 19, wherein the housing has exterior dimensions of less than 200×

100×

20 millimeters, wherein the projector comprises a plurality of laser light sources modulated by a MEMS scanning mirror.