Leadframe based photo voltaic electronic assembly

• US 8,609,978 B2
• Filed: 02/06/2008
• Issued: 12/17/2013
• Est. Priority Date: 02/14/2007
• Status: Expired due to Fees

• Current Assignee: Flextronics America LLC (Flextronics International Limited)
• Original Assignee: Flextronics America LLC (Flextronics International Limited)
• Inventors: Joshi, Rajeev
• Primary Examiner(s): Pillay, Devina
• Application Number:
  US12/069,094
• Publication Number:
  US 20080190480A1
• Time in Patent Office: 2,141 Days
• Field of Search: 136/246, 136/244, 136/251, 136/259, 136/256, 250/239
• US Class Current: 136/246
• CPC Class Codes: H01L 31/044 including bypass diodes bypass diodes in the junction box H02S40/34
• CPC Class Codes: H01L 31/052 Cooling means directly associated or integrated with the PV cell, e.g. integrated Peltier elements for active cooling or heat sinks directly associated with the PV cells cooling means in combination with the PV module H02S40/42
• CPC Class Codes: H01L 31/0521 using a gaseous or a liquid coolant, e.g. air flow ventilation, water circulation
• CPC Class Codes: H01L 31/054 Optical elements directly associated or integrated with the PV cell, e.g. light-reflecting means or light-concentrating means
• CPC Class Codes: H01L 31/0543 comprising light concentrating means of the refractive type, e.g. lenses
• CPC Class Codes: Y02E 10/52 PV systems with concentrators
• CPC Class Codes: Y10T 29/49002 Electrical device making

Abstract

A leadframe based photovoltaic assembly and method for assembling the same is disclosed. The photovoltaic assembly comprises a first and second mold compounds to effectuate the accurate placement of an optical concentrator above a photovoltaic cell. The photovoltaic assembly is able to be assembled using existing mature semiconductor packaging technologies.

Claims

1. A mounting assembly for a photovoltaic device comprising:

a. a metal substrate having a front surface and a back surface;

b. a current bus positioned lateral to the metal substrate;

c. a first mold compound encapsulating at least a portion of the metal substrate, wherein the first mold compound and the metal substrate form a substantially planar surface and the first mold compound electrically isolates the metal substrate and the current bus such that the metal substrate forms a first electrode and the current bus forms a second electrode;

d. at least one photovoltaic device mounted to the front surface of the metal substrate to effectuate transfer of current and heat therethrough, wherein the at least one photovoltaic device comprises an anode side on a first surface and a cathode side on a second surface opposite the first surface, and the cathode side is coupled to the first electrode and the anode side is electrically coupled to the second electrode, further wherein the second surface is entirely coupled to the metal substrate;

e. a second mold compound encapsulating at least a portion of the first mold compound, the second mold compound having an opening sized to receive a solar concentrator; and

f. a solar concentrator positioned within the opening of the second mold compound configured to concentrate light onto the anode side of the at least one photovoltaic cell.

2. The mounting assembly of claim 1 wherein the anode side of the photovoltaic device is coupled to at least one current bus by at least one bondwire to the second electrode.

3. The mounting assembly of claim 1 wherein the back surface of the metal substrate is oxidized.

4. The mounting assembly of claim 1 wherein the first mold compound is applied using a molding procedure.

5. The mounting assembly of claim 1 wherein the second mold compound is applied using a molding procedure.

6. The mounting assembly of claim 1 wherein the photovoltaic device is mounted on a non-encapsulated portion.

7. The mounting assembly of claim 1 further comprising a protection diode.

8. The mounting assembly of claim 1 wherein the mounting assembly is mounted on a passive heat sink.

9. The mounting assembly of claim 1 wherein the mounting assembly is mounted on an active heat sink.

10. The mounting assembly of claim 1 wherein the mounting assembly is liquid cooled.

21. The mounting assembly of claim 1, wherein the solar concentrator comprises multiple outer surfaces and the solar concentrator is positioned so that the light enters the solar concentrator through the multiple outer surface.

22. The mounting assembly of claim 1 wherein the second electrode partially circumscribes the first electrode.

24. The mounting assembly of claim 1 wherein the first mold compound, the current bus, and the metal substrate form the substantially planar surface.

25. The mounting assembly of claim 1 wherein the current bus is formed over the first mold compound.

26. The mounting assembly of claim 1 wherein the second mold compound comprises an electrical insulator.

27. The mounting assembly of claim 2 wherein the second mold compound encapsulates the at least one bondwire.

11. A method of assembling a photovoltaic device comprising:

a. stamping or etching a sheet metal to form a metal substrate and a current bus positioned lateral to the metal substrate;

b. applying a first mold compound to the metal substrate having a front and a back surface and encapsulating at least a portion of the metal substrate and thereby electrically isolating the metal substrate and the current bus such that the metal substrate forms a first electrode and the current bus forms a second electrode;

c. mounting at least one photovoltaic device having an anode side on a first surface and a cathode side on a second surface opposite the first surface such that the cathode side is mounted to the first electrode and the anode side is electrically coupled to the second electrode, and the second surface is entirely coupled to the metal substrate;

d. applying a second mold compound and encapsulating at least a portion of the first mold compound;

e. forming an opening in the second mold compound sized to receive a solar concentrator; and

f. mounting a solar concentrator configured to concentrate light on the photovoltaic device, such that more than one surface of the solar concentrator is able to be exposed to the light before the light enters the solar concentrator.

12. The method of claim 11 further comprising cutting a tie bar to effectuate electrical isolation between the first electrode and second electrode.

13. The method of claim 11 wherein the back surface of the metal substrate is oxidized.

14. The method of claim 11 wherein the first mold compound is applied using a molding procedure.

15. The method of claim 11 wherein the second mold compound is applied using a molding procedure.

16. The method of claim 11 wherein the photovoltaic device is mounted on a non-encapsulated portion.

17. The method of claim 11 wherein further comprising a mounting a protection diode.

18. The method of claim 11 further comprising mounting the assembly on a passive heat sink.

19. The method of claim 11 further comprising mounting the assembly on an active heat sink.

20. The method of claim 11 further comprising mounting the assembly on a liquid cooling mechanism.

23. The method of claim 11 further comprising mounting bondwires from the anode of the photovoltaic device to the second electrode.