Photovoltaic cells with electrodes adapted to house conductive paste

• US 9,899,546 B2
• Filed: 09/17/2015
• Issued: 02/20/2018
• Est. Priority Date: 12/05/2014
• Status: Active Grant

• Current Assignee: Tesla Inc.
• Original Assignee: Tesla Inc.
• Inventors: Reddy, Anand J.
• Primary Examiner(s): LEONG, SUSAN DANG
• Application Number:
  US14/857,653
• Publication Number:
  US 20160163888A1
• Time in Patent Office: 887 Days
• CPC Class Codes: B23P 19/04 for assembling or disassembling parts
• CPC Class Codes: H01L 31/022433 Particular geometry of the grid contacts
• CPC Class Codes: H01L 31/0443 comprising bypass diodes integrated or directly associated with the devices, e.g. bypass diodes integrated or formed in or on the same substrate as the photovoltaic cells
• CPC Class Codes: H01L 31/049 Protective back sheets
• CPC Class Codes: H01L 31/0504 specially adapted for series or parallel connection of solar cells in a module
• CPC Class Codes: H01L 31/0516 specially adapted for interconnection of back-contact solar cells
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: H01L 31/188 Apparatus specially adapted for automatic interconnection of solar cells in a module
• CPC Class Codes: H02S 20/25 Roof tile elements
• CPC Class Codes: H02S 50/10 Testing of PV devices, e.g. of PV modules or single PV cells testing of semiconductor devices during manufacturing H01L22/00
• CPC Class Codes: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy

Abstract

One embodiment of the present invention provides an electrode grid positioned at least on a first surface of a photovoltaic structure. The electrode grid can include a number of finger lines and an edge busbar positioned at an edge of the photovoltaic structure. The edge busbar can include one or more paste-alignment structures configured to facilitate confinement of conductive paste used for bonding the edge busbar to an opposite edge busbar of an adjacent photovoltaic structure.

Claims

1. An electrode grid positioned at least on a first surface of a photovoltaic structure, comprising:

a number of finger lines; and

an edge busbar positioned at an edge of the photovoltaic structure, wherein the edge busbar includes one or more paste-alignment structures configured to facilitate confinement of conductive paste used for bonding the edge busbar to an opposite edge busbar of an adjacent photovoltaic structure.

2. The electrode grid of claim 1, wherein the paste-alignment structures include one or more alignment pads.

3. The electrode grid of claim 2, wherein a respective alignment pad is located at an intersection between a finger line and the edge busbar.

4. The electrode grid of claim 2, wherein a respective alignment pad includes a plurality of trenches.

5. The electrode grid of claim 4, wherein the trenches include areas that are absent of conductive material that forms the edge busbar, and wherein the trenches are formed in a same fabrication process that forms the edge busbar.

6. The electrode grid of claim 5, wherein forming the trenches involves exposing dry film resist via a patterned mask which defines the edge busbar and locations and sizes of the trenches.

7. The electrode grid of claim 4, wherein the trenches are formed by partially etching the edge busbar at predetermined locations.

8. The electrode grid of claim 4, wherein the trenches are aligned in a direction parallel to the edge busbar.

9. The electrode grid of claim 4, wherein a respective trench has a width between 30 and 200 microns.

10. The electrode grid of claim 1, wherein the paste-alignment structures include a channel running a length of the edge busbar.

11. The electrode grid of claim 1, wherein the edge busbar includes a Cu layer formed using an electroplating process.

12. A photovoltaic structure, comprising:

a semiconductor multilayer structure; and

an electrode grid positioned on a first surface of the photovoltaic structure, wherein the electrode grid comprises;

a number of finger lines; and

an edge busbar positioned at an edge of the first surface, wherein the edge busbar includes a paste-alignment structure configured to facilitate confinement of conductive paste used for bonding the edge busbar to an opposite edge busbar of an adjacent photovoltaic structure.

13. The photovoltaic structure of claim 12, further comprising a second electrode grid positioned on a second surface of the photovoltaic structure, wherein the second electrode grid comprises a second edge busbar positioned at an edge of the second surface, and wherein the second edge busbar includes a second paste-alignment structure.

14. The photovoltaic structure of claim 12, wherein the paste-alignment structure includes an alignment pad.

15. The photovoltaic structure of claim 14, wherein the alignment pad is located at an intersection between a finger line and the edge busbar.

16. The photovoltaic structure of claim 14, wherein the alignment pad includes a plurality of trenches.

17. The photovoltaic structure of claim 16, wherein the trenches include areas that are absent of conductive material that forms the edge busbar, and wherein the trenches are formed in a same fabrication process that forms the edge busbar.

18. The photovoltaic structure of claim 17, wherein forming the trenches involves exposing dry film resist via a patterned mask which defines the edge busbar and locations and sizes of the trenches.

19. The photovoltaic structure of claim 16, wherein the trenches are formed by partially etching the edge busbar at predetermined locations.

20. The photovoltaic structure of claim 16, wherein the trenches are aligned in a direction parallel to the edge busbar.

21. The photovoltaic structure of claim 16, wherein a respective trench has a width between 30 and 200 microns.

22. The photovoltaic structure of claim 12, wherein the paste-alignment structure includes a channel running a length of the edge busbar.

23. The photovoltaic structure of claim 12, wherein the edge busbar includes a Cu layer formed using an electroplating process.