Electronic Devices Comprising Two Encapsulant Films

Patent metadata

Field	Value
Publication number	US-2016276512-A1
Application number	US-201414777693-A
Country	US
Kind code	A1
Filing date	Apr 16, 2014
Priority date	Apr 22, 2013
Publication date	Sep 22, 2016
Grant date	—

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

1 . An electronic device comprising 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 having a zero shear viscosity greater than that of the second encapsulating film.

2 . The electronic device of claim 1 wherein the back sheet contains fewer bumps than an comparable electronic device comprising a first encapsulating film having a zero shear viscosity less than or equal to that of a second encapsulating film.

3 . An electronic device comprising:
(i) a light-receiving and transmitting film; (ii) a first encapsulating film; (iii) at least one photovoltaic cell; (iv) a second encapsulating film; and (v) a back sheet; wherein the first encapsulating film is in direct contact with the light-receiving and transmitting film, the second encapsulating film is in direct contact with the back sheet, and the at least one photovoltaic cell is in direct contact with the first and second encapsulating films, and wherein the first encapsulating film has a zero shear viscosity greater than that of the second encapsulating film.

4 . The electronic device of claim 1 wherein the zero shear viscosity of the first encapsulating film is within 700 to 10,000 Pa·s of the shear viscosity of the second encapsulating film.

5 . The electronic device of claim 1 wherein the second encapsulating film has a zero shear viscosity of 400 to 900 Pa·s.

6 . The electronic device of claim 1 wherein the second encapsulating film comprises a silane-grafted ethylene/alpha-olefin interpolymer.

7 . The electronic device of claim 6 wherein the second encapsulating film further comprises an ethylene/alpha-olefin interpolymer.

8 . The electronic device of claim 6 wherein the silane-grafted ethylene/alpha-olefin interpolymer comprises 5-100 wt % of the second encapsulating film based on total weight of the second encapsulating film.

9 . The electronic device of claim 6 wherein the silane-grafted ethylene/alpha-olefin interpolymer is a silane-grafted ethylene/octene interpolymer.

10 . The electronic device of claim 7 wherein the ethylene/alpha-olefin interpolymer comprises 0-50 wt % of the second encapsulating film based on total weight of the second encapsulating film.

11 . A method for reducing bumps in an electronic device comprising
selecting first encapsulant film having a first zero shear viscosity; and selecting a second encapsulant film having a second zero shear viscosity, wherein the first zero shear viscosity is within 700 to 10,000 Pa·s of the second zero shear viscosity.

12 . The method of claim 11 wherein the second encapsulant film comprises a silane-grafted ethylene/alpha-olefin interpolymer.

13 . The method of claim 11 comprising forming a laminated structure comprising the first encapsulant film and the second encapsulant film.

14 . The method of claim 13 wherein the forming a laminated structure comprises
bringing a light-receiving and transmitting top sheet in direct contact with the first encapsulant film;
bringing a back sheet in direct contact with the second encapsulant film;
securing at least one photovoltaic cell between and in direct contact with the first and second encapsulant films such that portions of the first and second encapsulant films are in direct contact with each other; and
laminating and adhering the light-receiving and transmitting top sheet, first encapsulant film, second encapsulant film and the back sheet at a lamination temperature.

15 . The method of claim 14 further comprising crosslinking the silane-containing interpolymer.

16 . The electronic device of claim 3 wherein the zero shear viscosity of the first encapsulating film is within 700 to 10,000 Pa·s of the shear viscosity of the second encapsulating film.

17 . The electronic device of claim 3 wherein the second encapsulating film has a zero shear viscosity of 400 to 900 Pa·s.

18 . The electronic device of claim 3 wherein the second encapsulating film comprises a silane-grafted ethylene/alpha-olefin interpolymer.

19 . The electronic device of claim 18 wherein the second encapsulating film further comprises an ethylene/alpha-olefin interpolymer.

20 . The electronic device of claim 18 wherein the silane-grafted ethylene/alpha-olefin interpolymer comprises 5-100 wt % of the second encapsulating film based on total weight of the second encapsulating film.

Assignees

• Dow Global Technologies Llc

Inventors

• Nanjundiah Kumar
• Naumovitz John A
• White Michael D

Classifications

• Y02E10/50

  Photovoltaic [PV] energy · CPC title

• 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

• H01L31/0488 Primary

  Electricity · mapped topic