Front surface metallization and encapsulation of solar cells

• US 4,380,112 A
• Filed: 09/14/1981
• Issued: 04/19/1983
• Est. Priority Date: 08/25/1980
• Status: Expired due to Fees

• Current Assignee: Spire Corporation
• Original Assignee: Spire Corporation
• Inventors: Little, Roger G.
• Primary Examiner(s): Weisstuch, Aaron
• Application Number:
  US06/301,480
• Time in Patent Office: 582 Days
• Field of Search: 29/572, 156/272, 65/36, 65/59 R, 136/251, 136/256, 136/259, 357/30 J, 357/65, 357/68, 357/73
• US Class Current: 438/64
• CPC Class Codes: H01L 31/022425 for solar cells
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/1804 comprising only elements of Group IV of the Periodic Table
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: Y02E 10/547 Monocrystalline silicon PV cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

Method and apparatus for the front surface metallization and encapsulation of solar cells of the type comprising p and n semiconductor strata separated by a barrier junction, and front and rear conducting strata constituting electrical contacts, wherein the front conducting stratum is a novel metallic grid permitting transmission of solar radiation to the semiconductor strata. This metallic grid is in the form of a mesh of wires of sufficiently high tensile strength to be self-supporting while being drawn from spools or the like into contact with one or more components of the solar cell before completion of the cells'"'"'s fabrication.

The method is characterized in that the metallic grid, in the form of the mesh of wires, is encapsulated between a transparent cover plate and the exposed front surface of the semiconductor strata, the mesh forming an electrical contact with the front surface of the semiconductor strata simultaneously that the plate is electrostatically bonded thereto.

The apparatus is preferably automated and conveyorized.

Claims

1. A method of front surface metallization and encapsulation for solar cells comprising:

(a) providing a transparent plate having inner and outer surfaces;

(b) heating said plate so as to soften its said inner surface;

(c) pressing a mesh of wires fed from spools into said softened plate inner surface;

(d) providing a semiconductor wafer having front and rear semiconductor strata; and

(e) bonding said plate inner surface, together with said mesh of wires embedded therein, to said semiconductor wafer.

2. A method of front surface metallization encapsulation for solar cells comprising:

(a) providing a transparent plate having inner and outer surfaces;

(b) depositing an anti-reflective coating onto said plate inner surface;

(c) heating said plate so as to soften its said inner surface;

(c) stretching a mesh of wires fed from wire feeding means over a mandrel and pressing therewith said mesh of wires into said softened plate inner surface;

(e) providing a semiconductor wafer having front and rear semiconductor strata; and

(f) bonding said plate inner surface, together with said mesh of wires embedded therein, to said semiconductor wafer.

3. A continuous method of front surface metallization and encapsulation for solar cells comprising:

(a) stretching a plurality of wires over an endless belt;

(b) periodically dispensing at least one metallic strip over and normal to said plurality of wires so as to extend over said wires as said wires are periodically advanced by an indexing motion of said endless belt;

(c) periodically dispensing a transparent plate onto said plurality of wires and over said one metallic strip;

(d) heating said transparent plate;

(e) pressing said plurality of wires and said one metallic strip into a softened surface of said plate;

(f) periodically dispensing and mating a surface of a semiconductor wafer having a p-n junction with said softened surface of said transparent plate, thereby embedding said plurality of wires and said one metallic strip in said softened surface; and

(g) electrostatically bonding said plate surface to said semiconductor surface, with said wires and said strip forming electrical contact with said semiconductor surface.

4. The continuous method of claim 3 further including applying pressure to force said plate surface to said semiconductor surface during said electrostatic bonding of said surfaces to each other.