Compliant electrically connective bumps for an adhesive flip chip integrated circuit device and methods for forming same

A method for forming an electrically conductive compliant bump on a base having at least one electrical connection for connecting to the compliant bump for an adhesive flip chip integrated circuit device, the method comprising the steps of:

• forming a compressible polymer bump over said electrical connection;
• electrolessly plating a thin conductive metal layer on the base and the polymer bump, said thin conductive metal layer in electrical contact with the at least one electrical connection and protecting the at least one electrical connection;
• forming a photoresist mask layer on the thin conductive metal layer, said photoresist mask having an opening of a size corresponding to the surface area of the compliant bump;
• electrolytically plating a ductile and compliant metal layer over the surface area defined by the photoresist mask to form an electrically conductive metallization layer comprising the ductile and compliant metal layer and a portion of the thin conductive metal layer over the polymer bump and a portion of the electrical connection;
• removing the photoresist mask to expose the remaining portion of the thin conductive metal layer;
• removing the remaining portion of the thin conductive metal layer to form a compliant bump that is electrically conductive with the at least one electrical connection and that is compliant according to the compliant properties of the polymer bump and metallization layer;
• such that the compliant bump is connectable between the at least one electrical connection and an electrical connection point through compression and adhesion of an adhesive flip chip integrated circuit.