(US5151386-A)      Applying a metallised conductor to an uneven surface of a crystalline Si semiconductor solar cell substrate comprises (a) providing a pad printing appts.; (b) positioning a crystalline Si semiconductor substrate on the support; (c) filling the plate cavity with a metal-contg. printing ink; (d) contacting the plate with the pad so printing ink adheres to the pad; (e) moving the pad into engagement with the substrate surface; and (f) moving the pad out of contact with the substrate, where printing ink is transferred to the one surface. Compsn. and configuration of the pad, depth of the cavity and compsn. of the printing ink are selected so ink transfer to the substrate surface is of uniform thickness of 2-4 mils.    ADVANTAGE -   Contacts are applied to solar cell substrate cheaply, with high throughput rates and low substrate breakage rates.    (JP5502759-W)      Metallised contact pattern is applied to a solar cell substrate by filling the etched cavity of a pad printing appts. plate with a metallic printing ink; contacting the plate with a flexible pad to allow ink to adhere to the pad; and contactng the pad with the substrate surface to transfer the ink in the desired contact pattern.    Pref. the ink contains a pyrolysable binder and solvent and is dried and fired after printing. The ink has a viscosity of about 50 poise at 25 deg. C and a shear rate of about 10/sec. Al metallisation may be applied from an Al ink, followed by Ag metallisation, e.g. electrodes, from an Ag/glass frit ink.    ADVANTAGE -   Metallisation patterns of uniform thickness can be formed on uneven substrates, esp. poly Si substrates (claimed) produced by e.g. the EFG method    (EP495035-B1)      Metallised contact pattern is applied to a solar cell substrate by filling the etched cavity of a pad printing appts. plate with a metallic printing ink; contacting the plate with a flexible pad to allow ink to adhere to the pad; and contacting the pad with the substrate surface to transfer the ink in the desired contact pattern.    Pref. the ink contains a pyrolysable binder and solvent and is dried and fired after printing. The ink has a viscosity of about 50 poise at 25 deg C and a shear rate of about 10/sec.. Al metallisation may be applied from an Al ink, followed by Ag metallisation, e.g. electrodes, from an Ag/glass frit ink.    ADVANTAGE -   Metallisation patterns of uniform thickness can be formed on uneven substrates, esp. poly Si substrates (claimed) produced by e.g. the EFG method.