Structured relief dielectric heat sink for planar photovoltaic cells and semiconductor devices

• US 8,537,554 B1
• Filed: 05/17/2010
• Issued: 09/17/2013
• Est. Priority Date: 05/15/2009
• Status: Active Grant

• Current Assignee: Energy Related Devices, Inc.
• Original Assignee: Energy Related Devices, Inc.
• Inventors: Hockaday, Robert G.
• Primary Examiner(s): SMITH, COURTNEY L
• Application Number:
  US12/800,537
• Time in Patent Office: 1,219 Days
• Field of Search: 174383-386, 174520-531, 361676-678, 361/679.46, 361688-690, 361/707, 361/709, 361/710, 361712-713, 361/728, 361/750
• US Class Current: 361/713
• 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 23/467 by flowing gases, e.g. air H01L23/473 takes precedence
• 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: H01L 31/0521 using a gaseous or a liquid coolant, e.g. air flow ventilation, water circulation
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

Distribution and coupling of waste heat from planar non-concentration photovoltaic cells and semiconductor electrical devices is enhanced by forming dielectric relief structures and thermal conductive and emissive coatings on the cover and/or backing plate. The composite relief structures of layers, voids, and fins on the back surface mitigate the differential thermal expansion of dissimilar material and optimize convective heat transfer and radiant heat transfer with respect to costs. This leads to higher performance of the photovoltaic and semiconductor cells, a stronger and lighter backing plate components, and lower cost per watt for mounted devices.

Claims

1. Apparatus comprising a heat removing layer for planar mounting to semiconductor electrical device, wherein the heat removing layer is a dielectric material, the dielectric material being largely planar to the plane of the semiconductor device on a front side of the dielectric material facing the semiconductor device, a plurality of dielectric relief structures formed in the dielectric material on a back side facing away from the semiconductor device that protrude into fluid flow are largely non-planar to the plane of the semiconductor device, wherein the dielectric relief structures taper away in thickness as the dielectric relief structures protrude into fluid flow, at least one other layer mounted on the back of the dielectric material, and a plurality of voids within the dielectric material or between the semiconductor electrical device and the dielectric material or between the dielectric material and the at least one other layer formed on the back of the dielectric material.

2. The apparatus of claim 1, wherein the at least one other layer is a thermal conductive layer on the plural dielectric relief structures, and a radiant emissive coating on the thermal conductive layer on the dielectric relief structures.

3. The apparatus of claim 1, wherein a dielectric material has with a similar coefficient of thermal expansion to the semiconductor electrical devices.

4. The apparatus of claim 2, wherein the thermal conductive layer has a dissimilar coefficient of thermal expansion to the dielectric material and wherein the voids are between the thermal conductive layer and the dielectric material layer.

5. The apparatus of claim 4, wherein the voids are located in proximity to the back side of each relief structure to relieve differential thermal expansion stress.

6. The apparatus of claim 4, wherein the thermal conductive layer has bends and voids at bases of the relief structures to relieve differential thermal expansion stress.

7. The apparatus of claim 4, wherein the semiconductor electrical device is a photovoltaic cell, thermoelectric cell, light emitting diode, electrical switching diode, transistor, or integrated circuit.

8. The apparatus of claim 1, wherein the relief structure is formed by extruding, rolling, stamping, laminating, molding a suspension or powder, painting, printing, bonding, gluing the dielectric material.

9. The apparatus of claim 2, wherein the dielectric material forms a relief structure with voids by partially extruding into cavities, or forming bubbles into the dielectric material into the thermal conductive layer.

10. The apparatus of claim 2, wherein, thermal conductive layer further comprises metal structures formed by painting, welding, bonding, gluing, electroplating, bending, plasma spraying, laminating, or attaching metal structures or other thermally conductive structures of plates, foils, films, granules, hairs, fins, polymorphic structures, or rods.

11. The apparatus of claim 1, wherein the relief structures in the dielectric material have shapes of bumps, lenses, rods, cones, rectangles, pyramids, ridges, segmented ridges, segmented patterns, hairs, pedestals, networks of ridges, fins, curved fins, asymmetric features, polymorphic structures, crescents, ellipses, barchans, and sand-dune like shapes.

12. The apparatus of claim 1, wherein the relief structures act to create, mixing or vortex flow in flow passing across surfaces of the relief structures.

13. The apparatus of claim 2, wherein the radiant emissive coating is formed with a deposit, paint or surface modification.

14. The apparatus of claim 2, wherein the radiant emissive coating has a high emissivity in infrared and low absorption in visible light spectrum.

15. The apparatus of claim 2, wherein the radiant emissive coating contains carbon black, titanium dioxide, voids, water absorbing compounds, clays, zeolite, silica gel, or a phase change material.

16. The apparatus of claim 2, wherein the thermal conductive and/or radiant emissive coating has discontinuities or periodic surface folds.

17. The apparatus of claim 1, wherein the dielectric material is thicker near a perimeter of the layer to for structural strength.

19. The apparatus of claim 1, wherein in the dielectric material is transparent to visible light.

20. The apparatus of claim 1, wherein the dielectric material is transparent to light and is a conduit of light to photovoltaic cells.

21. The apparatus of claim 2, wherein the thermal conductive layer is transparent to visible light.

22. The apparatus of claim 2, wherein the radiant emissive coating is reflective and/or transparent to visible light.

23. The apparatus of claim 1, wherein the dielectric material layer that forms the flat front and back relief structures is made of glass, plastic, ceramics, glass fiber reinforced polymer, metal oxide impregnated polymer, alumina powder impregnated polymer, graphite impregnated polymer, metal impregnated polymer, silicone rubber, butyl rubber, urethane polymer, or ethylene vinyl acetate, the radiant emissive coating is made of carbon black loaded polymers, aluminum oxide anodized layer, titanium dioxide, titanium dioxide loaded polymers, glass encapsulated titanium dioxide, zeolite, acrylic hydro gel, sodium sulfate hydrate encapsulated in silicone rubber, waxes, polymers, or sodium sulfate hydrate encapsulated in urethane polymer, or sodium sulfate encapsulated in silicone rubber.

24. The apparatus of claim 2, wherein the thermal conductive layer on the dielectric material is made of silver, copper, aluminum, iron, tin, brass, zinc, aluminum oxide, silicon carbide, zirconium, graphite, carbon fibers, metal powder loaded polymers, or metal oxide loaded polymers.

25. The apparatus of claim 2, wherein the radiant emissive coating is made of carbon black loaded polymers, aluminum oxide anodized layer, titanium dioxide, titanium dioxide loaded polymers, glass encapsulated titanium dioxide, zeolite, acrylic hydro gel, sodium sulfate hydrate encapsulated in silicone rubber, waxes, polymers, or sodium sulfate hydrate encapsulated in urethane polymer, or sodium sulfate encapsulated in silicone rubber.

18. Apparatus comprising a heat removing layer for planar mounting to semiconductor electrical device, wherein the heat removing layer is a dielectric material, the dielectric material being largely planar to the plane of the semiconductor device on a front side of the dielectric material facing the semiconductor device, a plurality of dielectric relief structures formed in the dielectric material on a back side facing away from the semiconductor device, at least one other layer mounted on the back of the dielectric material, and a plurality of voids within the dielectric material and between the semiconductor electrical device and the dielectric material, or between the dielectric material and the at least one other layer formed on the back of the dielectric material, wherein the dielectric material is not transparent to visible light and is reflective, scatters, scintillates, or phosphorescent or absorptive.