| 20110197960 | METHOD FOR APPLYING FULL BACK SURFACE FIELD AND SILVER BUSBAR TO SOLAR CELL - A method is provided for applying back contact silver busbars to an aluminum back surface field (BSF) of a solar cell. The method involves providing a solar cell substrate having a front side and a back side; printing a full aluminum backing layer on the back side of the solar cell substrate; drying the printed aluminum backing layer to yield a full aluminum layer; printing and drying a peeling paste on the full aluminum layer in areas where the silver busbars are desired; printing and drying a front contact silver paste on the front side of the solar cell substrate to produce a front grid electrode; co-firing and cooling the front and back sides of the solar cell, wherein during firing the peeling paste wets excess aluminum powder in the aluminum layer, such that during cooling of the solar cell the peeling paste contracts, solidifies, and peels off with the excess aluminum powder to leave a full aluminum BSF having open areas; and printing, drying, and firing a back contact silver paste on the open areas of the BSF to yield silver busbars. | 08-18-2011 |
