Process to allow electrical and mechanical connection of an electrical device with a face equipped with contact pads
A method of manufacturing an electrical device that is electrically and mechanically connectable to another electrical device is presented. The electrical device includes a face equipped with contact pads. The method includes applying an adhesive layer on the face equipped with contact pads. The adhesive layer is composed of a substance with adhesive properties. The method further includes creating a plurality of openings through the adhesive layer over each contact pad, and growing, electrolessly or electrochemically, small metal sticks in the areas where the openings have been created to form a plurality of conductive paths over each contact pad, the volume of which is defined by the openings.
1. A method of manufacturing an electrical device that is electrically and mechanically connectable to another electrical device, the electrical device having a face equipped with contact pads, the method comprises the steps of:
applying an adhesive layer on the face equipped with contact pads, the adhesive layer being composed of a substance with adhesive properties;
creating a plurality of openings through the adhesive layer over each contact pad; and
growing, electrolessly or electrochemically, small metal sticks in the areas where the openings have been created to form a plurality of conductive paths over each contact pad, the volume of the conductive paths being defined by the openings,
wherein the small sticks are configured to extend beyond a plane of the adhesive layer.
2. The method according to claim 1 further comprising the step of applying a fixing layer comprising a polyimide.
3. The method according to claim 2 wherein the plurality of openings are created through the fixing layer over each contact pad.
4. The method according to claim 1 wherein the metal sticks comprise nickel, palladium, or copper.
5. The method according to claim 1 wherein the conductive paths have a length longer than the thickness of the adhesive layer.
6. The method according to claim 1 wherein the diameter of the metal sticks is between 10 and 30 μm.
7. The method according to claim 1 wherein the small sticks extend beyond the plane of the adhesive layer after thermocompression of the adhesive layer.