reduction a precursor layer is first deposited by for example conventional photoresist spin coating the precursor is after a low temperature pre bake exposed using for example a step and repeat projection aligner and ultra violet uv light as a light source the portions of the precursor that have been exposed in this manner are cross linked thereby leaving unexposed regions that are not cross linked over the bonding pads during subsequent development the unexposed polyimide precursor layer over the bonding pads is dissolved thereby providing openings over the bonding pads a final step of thermal curing leaves a permanent high quality passivation layer of polyimide over the substrate the preferred material of the invention for the deposition of layer 34 of passivation is plasma enhanced silicon nitride pe si 3 n 4 deposited using pecvd technology at a temperature between about 350 and 450 degrees c with a pressure of between about 2 0 and 2 8 torr for the duration between about 8 and 12 seconds layer 32 of pe si 3 n 4 can be deposited to a thickness between about 200 and 800 angstrom layer 34 of pe si 3 n 4 is next patterned and etched to create openings in the layer 34 that overlay and align with the underlying contact pads 32 the etching of layer 34 of passivation can use ar cf 4 as an etchant at a temperature of between about 120 and 160 degrees c and a pressure of between about 0 30 and 0.