A method for manufacturing a flexible circuit
electrode array, comprising:a) depositing a
metal trace layer containing a base
coating layer, a conducting layer and a top
coating layer on said insulator
polymer base layer;b) applying a layer of
photoresist on said
metal trace layer and patterning said
metal trace layer and forming metal traces on said insulator
polymer base layer;c) activating said insulator
polymer base layer and depositing a top insulator polymer layer and forming one single insulating polymer layer with said base insulator polymer layer;d) applying a
thin metal layer and a layer of
photoresist on the surface of said insulator polymer layer and selective
etching said insulator layer and said top
coating layer to obtain at least one via; ande) filling said via with
electrode material.A layer of polymer is laid down. A layer of metal is applied to the polymer and patterned to create electrodes and leads for those electrodes. A second layer of polymer is applied over the metal layer and patterned to leave openings for the electrodes, or openings are created later by means such as
laser ablation. Hence the array and its supply cable are formed of a single body. Alternatively, multiple alternating
layers of metal and polymer may be applied to obtain more metal traces within a given width.The method provides an excellent adhesion between the polymer base layer and the polymer top layer and insulation of the trace metals and electrodes.