PROCESS OF FORMING A GRID CATHODE ON THE FRONT-SIDE OF A SILICON WAFER

摘要

A process for the production of a grid cathode on the front-side of a silicon wafer by applying and firing a metal paste on the silicon wafer in a front-side grid electrode pattern to form a seed grid cathode and subsequently subjecting the silicon wafer to a LIP process, wherein the metal paste comprises an organic vehicle and an inorganic content comprising (a) 90 to 98 wt.-% of at least one electrically conductive metal powder selected from the group consisting of nickel, copper and silver, and (b) 0.25 to 8 wt.-% of at least one glass frit selected from the group consisting of glass frits containing 47.5 to 64.3 wt.-% of PbO, 23.8 to 32.2 wt.-% of SiO2, 3.9 to 5.4 wt.-% of Al2O3, 2.8 to 3.8 wt.-% of TiO2 and 6.9 to 9.3 wt.-% of B2O3.