Patent ID: 8484994

Claim:
A method for obtaining an external covering of a photovoltaic device, said covering comprising a glass substrate having surface texturing in the form of rows of mutually parallel grooves that are spaced from each other by a regular distance d from the center of the external covering to ends of the external covering, the method comprising: providing a heat softened glass substrate at a first temperature; applying a roller having parallel reliefs to a surface of the heat softened glass substrate to thereby imprint said parallel reliefs onto the glass substrate; and cooling the imprinted glass substrate to a second temperature to thereby form the external covering of a photovoltaic device having said surface texturing: wherein the spacing of successive parallel reliefs on the impressing roller are less at the center of the roller compared to the ends of the roller; and wherein said successive reliefs are spaced to account for lateral contraction of the glass substrate between the first and second temperatures to thereby produce said texturing having rows of mutually parallel grooves spaced from each other by a regular distance d.