A new method and processing sequence is provided for the formation of solder
bumps
that are in contact with underlying aluminum contact pads. A patterned layer of
negative photoresist is interposed between a patterned layer of PE Si3N4
and a patterned layer of polyamide insulator. The patterned negative photoresist
partially overlays the aluminum contact pad and prevents contact between the layer
of polyamide insulator and the aluminum contact pad. By forming this barrier no
moisture that is contained in the polyamide insulator can come in contact with
the aluminum contact pad, therefore no corrosion in the surface of the aluminum
contact pad can occur.