Parallel interconnection of neighboring space-qualified solar cells via a common back plane

Patent metadata

Field	Value
Publication number	US-10790406-B2
Application number	US-201815868296-A
Country	US
Kind code	B2
Filing date	Jan 11, 2018
Priority date	Apr 7, 2014
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

A solar cell assembly for space application comprising a plurality of space-qualified solar cells and a support, the support comprising a conductive layer. The conductive layer is divided into a first conductive portion and a second conductive portion. Each space-qualified solar cell of the plurality of space-qualified solar cells comprising a front surface, a rear surface, and a first contact in correspondence with the rear surface. Each one of the plurality of space-qualified solar cells is placed on the first conductive portion with the first contact electrically connected to the first conductive portion so that the space-qualified solar cells are connected in parallel through the first conductive portion. A second contact of each space-qualified solar cell can be connected to the second conductive portion. The two conductive portions serve as bus bars of the space-qualified solar cell assembly.

First claim

The invention claimed is:

1. A method of preparing a solar cell array for space applications, the method comprising:
providing a plurality of III-V compound semiconductor multijunction solar cells, each solar cell of the plurality of solar cells comprising said front surface, a rear surface, a first contact in correspondence with the rear surface, and a respective metallic bonding pad on the front surface;
forming a polyimide film having a thickness of 1 mil to 4 mils and a conductive layer having a thickness of 1 micrometer to 50 micrometers attached to the polyimide film, the conductive layer comprising a first conductive section and a second conductive section electrically isolated from each other by at least one groove traversing the conductive layer, wherein the second conductive section comprises a plurality of substantially elongated subportions at least some of which extend between subportions of the first conductive section;
providing a conductive bonding material on the first conductive section;
positioning each solar cell of the plurality of solar cells on the conductive bonding material that is on the first conductive section such that the first contact of each solar cell of the plurality of solar cells is electrically connected to the first conductive section by way of the conductive bonding material and so that the solar cells are connected in parallel through the first conductive section, wherein each solar cell is disposed over the first conductive section but not over the second conductive section;
disposing a ceria doped borosilicate glass supporting member on a surface of each of the semiconductor solar cells; and
welding interconnects composed of a silver-plated nickel-cobalt ferrous alloy material to the respective metallic bonding pads on the solar cells, wherein the interconnects are electrically connected to the second conductive section of the conductive layer,
wherein each solar cell of the plurality of solar cells is a rectangular or substantially square solar cell having at least one III-V compound semiconductor layer and having a surface section of less than 1 cm 2 .

2. A method as defined in claim 1 , wherein the first conductive section and the second conductive section are interconnected by at least one diode.

3. A method as defined in claim 2 , wherein the at least one diode comprises a top side terminal and a rear side terminal, the at least one diode being placed on the second conductive section with said rear side terminal of the at least one diode electrically coupled to the second conductive section, the top side terminal of the at least one diode being electrically coupled to the first conductive section.

4. A method as defined in claim 2 , wherein the at least one diode comprises a top side terminal and a rear side terminal, the at least one diode being placed on the first conductive section with the rear side terminal of the at least one diode electrically coupled to the first conductive section, the top side terminal of the at least one diode being electrically coupled to the second conductive section.

5. A method as defined in claim 1 , wherein the groove follows a path consisting of a plurality of segments arranged one after the other starting with a first segment and ending with a final segment, each segment after the first segment extending at a right angle with respect to an immediately preceding segment, and wherein each of the segments of the groove has sidewalls that are straight in a direction of the path.

6. A method as defined in claim 1 , wherein at least one of said segments extends in parallel with another one of said segments.

7. A method as defined in claim 1 , wherein at least one portion of the groove follows a substantially meandering path.

8. A method as defined in claim 1 , wherein a total surface area of the first conductive section that faces away from the polyimide film is larger than a total surface area of the second conductive section that faces away from the polyimide film.

9. A method as defined in claim 1 , wherein the plurality of solar cells placed on the first conductive section form a plurality of rows of solar cells, each solar cell of the plurality of solar cells being connected to a subportion of the second conductive section extending between two rows of solar cells.

10. A method as defined in claim 1 , wherein the conductive bonding material is an indium alloy.

11. A method as defined in claim 10 , wherein the bonding material is indium lead.

12. A method as defined in claim 1 , wherein the conductive layer comprises copper.

13. A method as defined in claim 1 , wherein the first contact of each solar cell of the plurality of solar cells comprises a conductive layer extending over a substantial portion of the rear surface of each solar cell of the plurality of solar cells.

14. A method of preparing a solar cell assembly designed for space applications, the method comprising:
providing a plurality of III-V compound semiconductor multijunction solar cells, each solar cell of the plurality of solar cells comprising a front surface, a rear surface, a first contact in correspondence with the rear surface, and a second contact including a metallic bonding pad on the front surface;
forming a polyimide film having a thickness of 1 mil to 4 mils and a copper conductive layer having a thickness of 1 micrometer to 50 micrometers attached to the polyimide film to mitigate outgassing, the conductive layer comprising a first conductive section and a second conductive section;
forming at least one groove traversing the conductive layer, the groove comprising a plurality of segments, at least one of said segments extending in parallel with another one of said segments so that the groove electrically isolates the first conductive section of the conductive layer and the second conductive section of the conductive layer from each other, and wherein the second conductive section has a plurality of substantially elongated subportions that extend between respective elongated subportions of the first conductive section, wherein the elongated subportions of the first conductive section are connected electrically to a common portion of the first conductive section disposed adjacent a first edge of the polyimide film, and the elongated portions of the second conductive section are connected electrically to a common portion of the second conductive section disposed adjacent a second edge of the polyimide film, wherein the second edge is opposite the first edge, and wherein the first conductive section has a larger surface section than the surface section of the second conductive section;
forming, at the first contact of each solar cell of the plurality of solar cells, a conductive layer extending over a substantial portion of the rear surface of each solar cell of the plurality of solar cells;
placing each solar cell of the plurality of solar cells on a conductive bonding material that is on the first conductive section, and electrically connected to the first conductive section using the conductive bonding material, wherein each solar cell is disposed over the first conductive section but not over the second conductive section, wherein the conductive bonding material enhances heat transfer between each solar cell and the first conductive portion and without an intervening conductor member, with the first contact of each solar cell of the plurality of solar cells electrically connected to the first conductive section so that the plurality of solar cells are connected in parallel through the first conductive section;
providing respective interconnects to connect the respective second contact

Assignees

• Solaero Tech Corp

Inventors

• Aiken Daniel
• Derkacs Daniel

Classifications

• H10F77/95

  Circuit arrangements · CPC title

• H10F77/93

  Interconnections · CPC title

• H10F71/127 Primary

  The active layers comprising only Group III-V materials, e.g. GaAs or InP · CPC title

• H10F77/935

  for photovoltaic devices or modules · CPC title

• H10F19/906

  characterised by the materials of the structures · CPC title