Electronic devices comprising two encapsulant films

Patent metadata

Field	Value
Publication number	US-10872990-B2
Application number	US-201816222112-A
Country	US
Kind code	B2
Filing date	Dec 17, 2018
Priority date	Apr 22, 2013
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

An electronic device comprises a first encapsulating film in direct contact with a light-receiving and transmitting film and a second encapsulating film in direct contact with a back sheet. The first encapsulating film has a zero shear viscosity greater than that of the second encapsulating film. The back sheet of the electronic device contains fewer bumps than the back sheet of a comparable electronic device having a first encapsulating film with a zero shear viscosity less than or equal to that of the second encapsulating film.

First claim

We claim:

1. An electronic device comprising:
a top sheet;
a front encapsulant film in direct contact with the top sheet, the front encapsulant film composed of a first ethylene/alpha-olefin copolymer composition having a first zero shear viscosity (ZSV) value;
a photovoltaic module having a top surface in direct contact with the front encapsulant film, the photovoltaic cell having ribbons extending therefrom;
a rear encapsulant film in direct contact with a bottom surface of the photovoltaic module, the rear encapsulant film composed of a second ethylene/alpha-olefin copolymer composition having a second ZSV value, the second ZSV value is from 700 Pa·s to 860 Pa·s and the first ZSV value is 4065 Pa·s;
a backsheet in direct contact with the rear encapsulant film, the backsheet having an unshrunken pre-lamination state and a shrunken post-laminated state, the backsheet imparting a shear stress upon the rear encapsulant film when the backsheet is subject to lamination conditions and moves from the pre-lamination state to the post-lamination state; and
the second ethylene/alpha olefin composition disperses the shear stress such that the shear stress does not reach the photovoltaic module.

2. The electronic device of claim 1 wherein the electronic device exhibits no bumps.

3. The electronic device of claim 2 wherein the ribbons are not buckled.

4. The electronic device of claim 3 wherein the backsheet comprises a layer composed of polyethylene terephthalate.

5. The electronic device of claim 4 wherein a portion of the front encapsulant film is in direct contact with a portion of the rear encapsulant film.

6. The electronic device of claim 5 wherein the first ethylene/alpha-olefin copolymer composition is a blend of ethylene/alpha-olefin copolymers;
the second ethylene/alpha-olefin copolymer composition is a blend of ethylene/alpha-olefin copolymers; and
first ethylene/alpha-olefin copolymer composition includes at least one ethylene/alpha-olefin copolymer that is different than the ethylene/alpha-olefin copolymers present in the second ethylene/alpha-olefin copolymer composition.

7. The electronic device of claim 1 , wherein the second ethylene/alpha-olefin copolymer composition has a ZSV value of 860 Pa·s.

8. The electronic device of claim 7 , wherein the first ZSV value is from 3,205 to 3,365 Pa·s greater than the second ZSV value.

9. The electronic device of claim 1 , wherein the second ethylene/alpha-olefin copolymer composition has a ZSV value of 700 Pa·s.

10. A process comprising:
providing an assembly in the following order (i) a top sheet, (ii) a front encapsulant film, (iii) a photovoltaic module, the photovoltaic module having ribbons extending therefrom, (iv) a rear encapsulant film, and (v) a backsheet;
providing a first ethylene/alpha-olefin copolymer composition having a first zero shear viscosity (ZSV) value for the front encapsulant film and providing a second ethylene/alpha-olefin copolymer composition having a second ZSV value for the rear encapsulant film such that the second ZSV value is from 700 Pa·s to 860 Pa·s and the first ZSV value is 4065 Pa·s;
subjecting the assembly to lamination conditions;
shrinking, under the lamination conditions, the backsheet;
imparting, with the shrinking, a shear stress onto the rear encapsulant film;
dispersing the shear stress with second ethylene/alpha-olefin copolymer such that the shear stress does not reach the photovoltaic module; and
forming an electronic device.

11. The process of claim 10 comprising
preventing, with the dispersing, the ribbons from buckling; and
forming an electronic device exhibiting no bumps.

12. The process of claim 11 comprising
providing a backsheet comprising a layer composed of polyethylene terephthalate.

13. The process of claim 12 comprising
subjecting the assembly to lamination conditions including a lamination temperature from 120° C. to 170° C.

14. The process of claim 10 , wherein the second ZSV value is 700 Pa·s.

15. The process of claim 14 , wherein the first ZSV value is from 3,205 to 3,365 Pa·s greater than the second ZSV value.

Assignees

• Dow Global Technologies Llc

Inventors

• Nanjundiah Kumar
• Naumovitz John A
• White Michael D

Classifications

• H10F71/00

  Manufacture or treatment of devices covered by this subclass (patterning processes to connect thin photovoltaic cells in integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/33; manufacture or treatment of encapsulations or containers for integrated devices, or assemblies of multiple devices, having photovoltaic cells H10F19/80; manufacture or treatment of integrated devices, or assemblies of multiple devices, comprising at least one element in which radiation controls the flow of current H10F39/00) · CPC title

• H10F19/85

  Protective back sheets · CPC title

• H10F19/804 Primary

  Materials of encapsulations · CPC title

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• H01L31/0481 Primary

  Electricity · mapped topic