SOLAR CELL INTERCONNECTION, MODULE, PANEL AND METHOD
A laminated module or panel of solar cells and a laminating method for making same comprise a top layer of melt flowable optically transparent molecularly flexible thermoplastic and a rear sheet of melt flowable insulating molecularly flexible thermoplastic both melt flowing at a temperature between about 80° C. and 250° C. and having a low glass transition temperature. Solar cells are encapsulated by melt flowing the top layer and rear sheet, and electrical connections are provided between front and back contacts thereof. Light passing through the transparent top layer impinges upon the solar cells and the laminated module exhibits sufficient flexural modulus without cross-linking chemical curing. Electrical connections may be provided by melt flowable electrically conductive molecularly flexible thermoplastic adhesive or by metal strips or by both.
1 . A laminated module of solar cells having front and back surfaces comprising:
a top layer of a melt flowed melt flowable optically transparent electrically insulating thermoplastic adhesive material having a first pattern of melt flowable electrically conductive thermoplastic adhesive thereon for making electrical connection to the front surfaces of solar cells;
a plurality of solar cells having front and back surfaces to which electrical connection may be made, said plurality of solar cells being laminated into said melt flowed top layer with the first patterns of melt flowable electrically conductive thermoplastic adhesive making electrical connection to the front surfaces of said plurality of solar cells,
whereby light may pass through said melt flowed optically transparent top layer to impinge upon the front surface of said plurality of solar cells;
a rear sheet of a melt flowed melt flowable electrically insulating thermoplastic adhesive material having a second pattern of melt flowable electrically conductive thermoplastic adhesive thereon for making electrical connection to the back surfaces of said plurality of solar cells,
said melt flowed rear sheet being laminated to said melt flowed top layer and to the back surfaces of said plurality of solar cells therein with the second patterns of melt flowable electrically conductive thermoplastic adhesive making electrical connection to the back surfaces of said plurality of solar cells;
wherein the first and second patterns of melt flowable electrically conductive thermoplastic adhesive are melt flowed to each other to provide an electrical connection between the front surface of one of said plurality of solar cells and the back surface of another of said plurality of solar cells,
whereby ones of said plurality of solar cells are electrically connected in series by the connection between the first and second patterns of electrically conductive thermoplastic adhesive.
2 . The laminated module of solar cells of claim 1 wherein the first pattern includes:
a first pattern of an electrically conductive metal on said top layer in the first pattern and the first pattern of melt flowable electrically conductive thermoplastic adhesive disposed on the first pattern of electrically conductive metal.
3 . The laminated module of solar cells of claim 1 wherein the first pattern includes:
an insulating pattern of a melt flowable electrically insulating thermoplastic adhesive on the first pattern of melt flowable electrically conductive thermoplastic adhesive, wherein the insulating pattern has a plurality of elongated areas at locations corresponding to locations at which edges of said plurality of solar cells are to be placed.
4 . The laminated module of solar cells of claim 1 wherein the second pattern includes:
a second pattern of an electrically conductive metal on said rear sheet in the second pattern and the second pattern of melt flowable electrically conductive thermoplastic adhesive disposed on the second pattern of electrically conductive metal.
5 . The laminated module of solar cells of claim 1 wherein the first and second patterns of melt flowable electrically conductive thermoplastic adhesive each include respective portions extending beyond edges of said plurality of solar cells, and wherein the respective extended portions thereof are melt flowed to each other to provide the electrical connection between the front surface of one of said plurality of solar cells and the back surface of another of said plurality of solar cells.
6 . The laminated module of solar cells of claim 1 wherein:
each of said plurality of solar cells includes a transparent electrically conductive front contact substantially covering the front surface thereof and the first pattern includes for each of said plurality of solar cells at least one elongated conductor having a plurality of relatively narrower elongated conductors extending substantially perpendicular thereto for making an electrical connection to the front contact of said solar cell; or
each of said plurality of solar cells includes at least one elongated electrically conductive front contact on the front surface thereof and the first pattern includes for each of said plurality of solar cells at least one elongated conductor corresponding to the at least one elongated electrically conductive front contact of said solar cell and located for making an electrical connection to the front contact of said solar cell; or
each of said plurality of solar cells includes at least two parallel elongated electrically conductive front contacts on the front surface thereof and the first pattern includes for each of said plurality of solar cells at least two parallel elongated conductors corresponding to the at least two parallel elongated electrically conductive front contacts of said solar cell and located for making an electrical connection to the front contacts of said solar cell.
7 . The laminated module of solar cells of claim 1 wherein the first pattern of melt flowable electrically conductive thermoplastic adhesive or the second pattern of melt flowable electrically conductive thermoplastic adhesive or both comprise:
at least one elongated continuous strip of melt flowable electrically conductive thermoplastic adhesive where said plurality of solar cells do not have a metalized contact on the front surface and/or on the back surface thereof; or
a plurality of areas comprising between about ten percent and 100 percent of the area of metalized contact where said plurality of solar cells have a metalized contact on the front surface and/or on the back surface thereof.
8 . The laminated module of solar cells of claim 1 wherein each of said plurality of solar cells includes an electrically conductive tab applied to a contact on the front surface or on the back surface thereof or on both surfaces thereof, said tab extending beyond an edge of the solar cell, and wherein said electrically conductive tab includes:
a solderable metal strip soldered to a metalized contact of the solar cell; or
a metal strip having on opposing broad surfaces thereof a plurality of areas comprising melt flowable electrically conductive thermoplastic adhesive covering between about ten percent and 100 percent of the area of said metal strip and melt flowable electrically insulating thermoplastic adhesive substantially covering the remaining area of said metal strip.
9 . The laminated module of solar cells of claim 1 further comprising
a glass layer on an exposed front surface of said melt flowable optically transparent top layer; or
a melt flowable optically transparent fluorinated polymer front layer on an exposed front surface of said melt flowable optically transparent top layer; or
a thermally conductive layer on an exposed rear surface of said melt flowable rear sheet; or
an ultraviolet resistant melt flowable layer on an exposed rear surface of said melt flowable rear sheet; or
any combination of the foregoing.
10 . The laminated module of solar cells of claim 1 wherein:
said top layer is not as thick as is said rear sheet; or
said top layer is at least as thick as are said solar cells; or
said top layer is not as thick as is said rear sheet and is at least as thick as are said solar cells.
11 . The laminated module of solar cells of claim 1 wherein said laminated module of solar cells comprises a laminated solar cell panel.
12 . The laminated module of solar cells of claim 1 wherein the thermoplastic adhesives of said top layer, of said first pattern of thermoplastic adhesive, of said rear sheet and of said second pattern of thermoplastic adhesive, comprise a molecularly flexible thermoplastic adhesive having a melt flow temperature in the range between about 80° C. and about 200° C. and having a glass transition temperature of less than about 0° C.
13 . A laminated module of solar cells having front and back surfaces comprising:
a top layer of a melt flowed melt flowable optically transparent electrically insulating thermoplastic adhesive material having a first pattern of melt flowable electrically conductive thermoplastic adhesive thereon for making electrical connection to the front surfaces of solar cells;
a plurality of solar cells having front and back surfaces to which electrical connection may be made, said plurality of solar cells being laminated into said melt flowed top layer with the first patterns of melt flowable electrically conductive thermoplastic adhesive making electrical connection to the front surfaces of said plurality of solar cells, and the back surfaces of said plurality of solar cells being exposed,
whereby light may pass through said melt flowed optically transparent top layer to impinge upon the front surface of said plurality of solar cells and connection may be made to the back surfaces thereof;
wherein the first pattern of melt flowable electrically conductive thermoplastic adhesive melt flowed to provide exposed electrical connections to the front surfaces of said plurality of solar cells, and
wherein the back surfaces of said plurality of solar cells are exposed for making electrical connection thereto,
whereby electrical connections to the front and back surfaces of said plurality of solar cells are exposed on the same surface of said laminated module of solar cells.
14 . The laminated module of solar cells of claim 13 further comprising:
a rear sheet of a melt flowed melt flowable electrically insulating thermoplastic adhesive material having a second pattern of melt flowable electrically conductive thermoplastic adhesive thereon for making electrical connection to the back surfaces of said plurality of solar cells, wherein the second pattern of melt flowable electrically conductive thermoplastic adhesive includes a portion extending beyond said plurality of solar cells;
said melt flowed rear sheet being laminated to said melt flowed top layer and to the back surfaces of said plurality of solar cells therein with the second patterns of melt flowable electrically conductive thermoplastic adhesive making electrical connection to the back surfaces of said plurality of solar cells;
wherein the respective portions of the first and second patterns of melt flowable electrically conductive thermoplastic adhesive that extend beyond said plurality of solar cells are melt flow laminated to each other to provide an electrical connection between the front surface of one of said plurality of solar cells and the back surface of another of said plurality of solar cells,
whereby ones of said plurality of solar cells are electrically connected in series by the connection between the first and second patterns of electrically conductive thermoplastic adhesive.
15 . The laminated module of solar cells of claim 13 wherein the first pattern includes:
a first pattern of an electrically conductive metal on said top layer in the first pattern and the first pattern of melt flowable electrically conductive thermoplastic adhesive disposed on the first pattern of electrically conductive metal.
16 . The laminated module of solar cells of claim 13 wherein the first pattern includes:
an insulating pattern of a melt flowable electrically insulating thermoplastic adhesive on the first pattern of melt flowable electrically conductive thermoplastic adhesive, wherein said insulating pattern has a plurality of elongated areas at locations corresponding to locations at which edges of said plurality of solar cells are to be placed.
17 . The laminated module of solar cells of claim 13 wherein:
the first pattern of melt flowable electrically conductive thermoplastic adhesive includes portions extending beyond edges of said plurality of solar cells and exposed near the back surfaces of said plurality of solar cells to provide the exposed electrical connections to the front surfaces of said plurality of solar cells.
18 . The laminated module of solar cells of claim 13 wherein:
each of said plurality of solar cells includes a transparent electrically conductive front contact substantially covering the front surface thereof and the first pattern includes for each of said plurality of solar cells at least one elongated conductor having a plurality of relatively narrower elongated conductors extending substantially perpendicular thereto for making an electrical connection to the front contact of said solar cell; or
each of said plurality of solar cells includes at least one elongated electrically conductive front contact on the front surface thereof and the first pattern includes for each of said plurality of solar cells at least one elongated conductor corresponding to the at least one elongated electrically conductive front contact of said solar cell and located for making an electrical connection to the front contact of said solar cell; or
each of said plurality of solar cells includes at least two parallel elongated electrically conductive front contacts on the front surface thereof and the first pattern includes for each of said plurality of solar cells at least two parallel elongated conductors corresponding to the at least two parallel elongated electrically conductive front contacts of said solar cell and located for making an electrical connection to the front contacts of said solar cell.
19 . The laminated module of solar cells of claim 13 wherein the first pattern of melt flowable electrically conductive thermoplastic adhesive comprises:
at least one elongated continuous strip of melt flowable electrically conductive thermoplastic adhesive where said plurality of solar cells do not have a metalized contact on the front surface thereof; or
a plurality of areas comprising between about ten percent and 100 percent of the area of metalized contact where said plurality of solar cells have a metalized contact on the front surface thereof.
20 . The laminated module of solar cells of claim 13 wherein each of said plurality of solar cells includes an electrically conductive tab applied to a contact on the front surface or on the back surface thereof or on both surfaces thereof, said tab extending beyond an edge of the solar cell, and wherein said electrically conductive tab includes:
a solderable metal strip soldered to a metalized contact of the solar cell; or
a solderable metal strip soldered to a metalized contact on the front surface of one solar cell and to a metalized contact on the back surface of an adjacent solar cell; or
a metal strip having on opposing broad surfaces thereof a plurality of areas comprising melt flowable electrically conductive thermoplastic adhesive covering between about ten percent and 100 percent of the area of said metal strip and melt flowable electrically insulating thermoplastic adhesive substantially covering the remaining area of said metal strip; or
a metal strip having on opposing broad surfaces thereof a plurality of areas comprising melt flowable electrically conductive thermoplastic adhesive covering between about ten percent and 100 percent of the area of said metal strip and melt flowable electrically insulating thermoplastic adhesive substantially covering the remaining area of said metal strip, wherein areas of melt flowable electrically conductive thermoplastic adhesive on one surface of said metal strip adhere to a metalized contact on the front surface of one solar cell and areas of melt flowable electrically conductive thermoplastic adhesive on the other surface of said metal strip adhere to a metalized contact on the back surface of an adjacent solar cell.
21 . The laminated module of solar cells of claim 13 further comprising
a glass layer on an exposed front surface of said melt flowable optically transparent top layer; or
a melt flowable optically transparent fluorinated polymer front layer on an exposed front surface of said melt flowable optically transparent top layer; or
a melt flowable optically transparent fluorinated polymer front layer on an exposed front surface of said melt flowable optically transparent top layer and a glass layer on an exposed front surface of said melt flowable optically transparent polymer front layer.
22 . The laminated module of solar cells of claim 21 wherein:
said melt flowable optically transparent fluorinated polymer layer is of a different material than is said melt flowable optically transparent top layer; or
said melt flowable optically transparent fluorinated polymer layer is of a different material than is said melt flowable optically transparent top layer and said melt flowable optically transparent fluorinated polymer layer and said melt flowable optically transparent top layer have respective melt flow temperatures in about the same temperature range.
23 . The laminated module of solar cells of claim 13 wherein:
said melt flowable top layer is at least as thick as are said solar cells.
24 . The laminated module of solar cells of claim 13 wherein the thermoplastic adhesives of said top layer and of said first pattern of thermoplastic adhesive comprise a molecularly flexible thermoplastic adhesive having a melt flow temperature in the range between about 80° C. and about 200° C. and having a glass transition temperature of less than about 0° C.
25 . A laminated module of solar cells having front and back surfaces comprising:
a top layer of a melt flowed melt flowable optically transparent electrically insulating molecularly flexible thermoplastic adhesive material having at least ten percent molecular crystallites that melt flow at a temperature in the range between about 80° C. and about 250° C. and having a glass transition temperature of less than about 0° C.; to bond to the front surfaces of solar cells;
a rear sheet of a melt flowed melt flowable electrically insulating molecularly flexible thermoplastic adhesive material having at least ten percent molecular crystallites that melt flow at a temperature in the range between about 80° C. and about 250° C. and having a glass transition temperature of less than about 0° C.; to bond to the back surfaces of solar cells;
a plurality of solar cells having front and back surfaces to which electrical connection may be made, said plurality of solar cells being encapsulated by the molecularly flexible thermoplastic adhesives of said melt flowed top layer and of said melt flowed rear sheet;
electrically conductive interconnection members providing electrical connections between the front surfaces of ones of said plurality of solar cells and the back surfaces of others of said plurality of solar cells;
wherein the melt flowable molecularly flexible thermoplastic adhesive of said top layer is bonded to the front surfaces of said plurality of solar cells and the melt flowable molecularly flexible thermoplastic adhesive of said rear sheet is bonded to the back surfaces of said plurality of solar cells,
whereby light may pass through said melt flowed optically transparent top layer to impinge upon the front surface of said plurality of solar cells;
wherein said laminated module including said top layer and said rear sheet exhibits a flexural modulus at about 60° C. that is at least fifty percent of the flexural modulus exhibited at about 20° C. without cross-linking chemical curing.
26 . The laminated module of solar cells of claim 25 wherein said interconnection members comprise:
a first pattern of melt flowable electrically conductive thermoplastic adhesive on said top layer making electrical connection to the front surfaces of said plurality of solar cells;
a second pattern of melt flowable electrically conductive thermoplastic adhesive on said rear sheet making electrical connection to the back surfaces of said plurality of solar cells,
each of the first and second patterns of melt flowable electrically conductive thermoplastic adhesive including respective portions extending beyond the edges of said plurality of solar cells that are melt flow connected to each other to provide an electrical connection between the front surface of one of said plurality of solar cells and the back surface of another of said plurality of solar cells,
whereby ones of said plurality of solar cells are electrically connected in series by the connection between the first and second patterns of electrically conductive thermoplastic adhesive.
27 . The laminated module of solar cells of claim 25 wherein said interconnection members comprise:
at least one elongated continuous strip of melt flowable electrically conductive thermoplastic adhesive where said plurality of solar cells do not have a metalized contact on the front surface and/or on the back surface thereof; or
a plurality of areas comprising between about ten percent and 100 percent of the area of metalized contact where said plurality of solar cells have a metalized contact on the front surface and/or on the back surface thereof.
28 . The laminated module of solar cells of claim 25 wherein said interconnection members comprise:
an electrically conductive tab applied to a contact on the front surface or on the back surface of or on both surfaces of each of said plurality of solar cells, each said tab extending beyond an edge of the solar cell, wherein said electrically conductive tab includes:
a solderable metal strip soldered to a metalized contact of the solar cell; or
a metal strip having on opposing broad surfaces thereof a plurality of areas comprising melt flowable electrically conductive thermoplastic adhesive covering between about ten percent and 100 percent of the area of said metal strip and melt flowable electrically insulating thermoplastic adhesive substantially covering the remaining area of said metal strip.
29 . The laminated module of solar cells of claim 25 wherein said interconnection members comprise:
solderable metal strips soldered to metalized contacts of said plurality of solar cells; or
metal strips each having on opposing broad surfaces thereof a plurality of areas comprising melt flowable electrically conductive thermoplastic adhesive covering between about ten percent and 100 percent of the area of said metal strip and melt flowable electrically insulating thermoplastic adhesive substantially covering the remaining area of said metal strip.