Electronics package suitable form implantation
The invention is directed to a method of bonding a hermetically sealed electronics package to an electrode or a flexible circuit and the resulting electronics package that is suitable for implantation in living tissue, such as for a retinal or cortical electrode array to enable restoration of sight to certain non-sighted individuals. The hermetically sealed electronics package is directly bonded to the flex circuit or electrode by electroplating a biocompatible material, such as platinum or gold, effectively forming a plated rivet-shaped connection, which bonds the flex circuit to the electronics package. The resulting electronic device is biocompatible and is suitable for long-term implantation in living tissue.
1. An implantable electronic device, comprising:
a) a substrate having one or more contacts and two or more layers of conductive adhesive on said contacts;
b) a flexible assembly having one or more bond pads and one or more layers of conductive adhesive on said bond pads;
c) said conductive adhesive connecting said contacts on said substrate with said bond pads on said flexible assembly; and
d) adhesive underfill in the remaining space between said substrate and said flexible assembly.
2. The device according to claim 1 wherein said flexible assembly comprises polyimide.
3. The device according to claim 1 wherein said substrate comprises a biocompatible ceramic.
4. The device according to claim 1 wherein said biocompatible ceramic comprises alumina.
5. The device according to claim 1 wherein said substrate is rigid.
6. The device according to claim 1 wherein said flexible assembly is a thin substrate circuit.
7. The device according to claim 1 wherein said conductive adhesive provides an electrical path between said input/output contacts and said bond pads.
8. The device according to claim 1 wherein said adhesive underfill is nonconductive.
9. The device according to claim 1 wherein said adhesive underfill contains epoxy.
10. The device according to claim 1 wherein said substrate is an electrically insulated substrate circuit.