Method of encapsulating a photovoltaic device

• US 5,273,608 A
• Filed: 02/06/1992
• Issued: 12/28/1993
• Est. Priority Date: 11/29/1990
• Status: Expired due to Term

• Current Assignee: United Solar Systems Corp.
• Original Assignee: United Solar Systems Corp.
• Inventors: Nath, Prem
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Stemmer, Daniel J.
• Application Number:
  US07/833,619
• Time in Patent Office: 691 Days
• Field of Search: 156/301, 156/300, 156/299, 156/302, 156/324, 156/192, 156/306.6, 156/164, 136/251, 136/245, 437/2
• US Class Current: 156/301
• CPC Class Codes: B32B 37/04 characterised by the partial melting of at least one layer
• CPC Class Codes: C09J 5/06 involving heating of the applied adhesive
• CPC Class Codes: H01L 31/048 Encapsulation of modules
• CPC Class Codes: H01L 31/1876 Particular processes or apparatus for batch treatment of the devices
• CPC Class Codes: Y02E 10/50 Photovoltaic [PV] energy
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product
• CPC Class Codes: Y10T 156/1095 Opposed laminae are running length webs
• CPC Class Codes: Y10T 156/1097 Lamina is running length web

Abstract

A flexible encapsulated photovoltaic device is prepared by disposing photovoltaic devices on a sheet of thermoplastic material, disposing a front encapsulant material atop the devices, and disposing a bottom encapsulant layer so as to provide a multi-layered structure. The multi-layered structure is rolled under tension so as to compress the layers and the roll is heated to activate the thermoplastic material and bond the layers together. Additional layers may be interposed prior to rolling.

Claims

1. A method of manufacturing an encapsulated flexible photovoltaic device, said method including the steps of:

providing a flexible, thin film photovoltaic device;

providing a first roll of adhesive material;

unwinding a portion of said first adhesive roll, while maintaining said first roll under tension;

disposing said photovoltaic device on said unwound portion of the tensioned first adhesive roll, such that said portion supports said device;

providing a roll of flexible back encapsulant material;

unwinding a portion of said flexible back encapsulant material roll, while maintaining said back encapsulant roll under tension;

providing a roll of front encapsulant material;

unwinding a portion of said front encapsulant material roll, while maintaining said front encapsulant roll under tension;

interleaving said materials so as to provide a layered structure comprising, in order, front encapsulant material, photovoltaic device, first adhesive material, and back encapsulant material;

rolling up said layered structure while maintaining tension on said rolls of materials so as to flex said photovoltaic device and to provide a tightly wound composite roll of said layered structure; and

heating said roll of layered structure for a period of time sufficient to activate said adhesive material.

2. The method of claim 1 including the further steps of:

providing a second roll of adhesive material;

unwinding a portion of said second roll of adhesive material while maintaining said second roll under tension; and

interleaving said materials so as to provide a layered structure comprising, in order, front encapsulant material, second adhesive material, photovoltaic device, first adhesive material, and back encapsulant material.

3. The method of claim 1 wherein the step of providing a roll of front encapsulant material includes providing a roll of front encapsulant material pretreated with second adhesive material.

4. The method of claim 2 including the further steps of:

providing a roll of dielectric material;

unwinding a portion of said roll of dielectric material while maintaining said dielectric roll under tension; and

interleaving said roll of dielectric material into the layered structure between the first adhesive material and the back encapsulant material.

5. The method of claim 4 including the further steps of:

providing a third roll of adhesive material;

unwinding a portion of said third roll of adhesive material while maintaining said third roll under tension; and

interleaving said roll of third adhesive material between the dielectric material and the back encapsulant material.

6. The method of claim 4 wherein the step of providing a roll of dielectric material includes providing a roll of dielectric material pretreated with a third adhesive material.

8. The method of claim 1 wherein the step of providing a flexible, thin film photovoltaic device comprises providing a plurality of interconnected subcells.

9. The method of claim 1 wherein the step of providing the first roll of adhesive material comprises providing a first roll of thermoplastic, hot-melt adhesive.

10. The method of claim 9, wherein the step of providing a first roll of thermoplastic hot-melt adhesive comprises providing a first roll of ethylene vinyl acetate polymer.

11. The method of claim 1 wherein the step of providing a roll of back encapsulant material comprises providing a roll of synthetic polymeric material.

12. The method of claim 1 wherein the step of providing a roll of back encapsulant material comprises providing a roll of a non-rigid metal.

13. The method of claim 12 wherein the step of providing a roll of a metal comprises providing a roll of galvanized steel.

14. The method of claim 12 wherein the step of providing a roll of a metal comprises providing a roll of aluminum.

15. The method of claim 1 wherein the step of providing a roll of front encapsulant material comprises providing a roll of a transparent, synthetic, organic polymeric material.

16. The method of claim 15 wherein the step of providing a roll of a transparent, synthetic, organic polymeric material comprises providing a roll of a transparent fluorocarbon polymer.

17. The method of claim 1 wherein the step of heating said roll of layered structure comprises disposing said roll in an oven.

18. The method of claim 17, including the further step of maintaining the oven at a temperature of at least 120°

C

19. The method of claim 1 including the further step of exposing the roll of layered structure to the source of heat for a time period of between 10 to 30 minutes.

20. The method of claim 1 including the further step of maintaining the rolls at a tension of at least 200 pounds while rolling up said layered structure.

7. The method of claim wherein the step of providing a flexible, thin film photovoltaic device comprises providing a single, continuous solar panel.

21. A method of manufacturing an encapsulated photovoltaic device, said method including the steps of:

providing a flexible, thin film photovoltaic device;

providing a first roll of adhesive material;

unwinding a portion of said first adhesive roll while maintaining said first roll under tension;

disposing said photovoltaic device on said unwound portion such that said portion supports said device;

providing a roll of flexible back encapsulant material;

unwinding a portion of said roll of back encapsulant material while maintaining said back encapsulated roll under tension;

providing a second roll of adhesive material;

unwinding a portion of said second roll of adhesive material while maintaining said second roll under tension;

providing a roll of flexible front encapsulant material;

unwinding a portion of said roll of front encapsulant material while maintaining said front encapsulant roll under tension;

interleaving said materials so as to provide a layered structure comprising, in order, front encapsulant material, second adhesive material, photovoltaic device, first adhesive material, and back encapsulant material;

rolling up said layered structure while maintaining tension on said rolls of material so as to flex said photovoltaic device and to provide a tightly wound roll of said layered structure; and

heating said roll of layered structure for a period of time sufficient to activate said adhesive materials.