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

摘要

A process of forming a front-grid electrode on a silicon wafer having an ARC layer, comprising the steps: (1) printing and drying a metal paste A comprising an inorganic content comprising 0.5 to 8 wt.-% of glass frit and having fire-through capability, wherein the metal paste A is printed on the ARC layer in a grid pattern which comprises (i) thin parallel finger lines forming a bottom set of finger lines and (ii) busbars intersecting the finger lines at right angle, (2) printing and drying a metal paste B comprising an inorganic content comprising 0 to 3 wt.-% of glass frit over the bottom set of finger lines to form a top set of finger lines superimposing the bottom set of finger lines, and (3) firing the double-printed silicon wafer, wherein the inorganic content of metal paste B contains less glass frit plus optionally present other inorganic additives than the inorganic content of metal paste A.