Biocompatible bonding method and electronics package suitable for 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, 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. A method of making an implantable device comprising:
providing a hermetic package configured to be implanted within a human body, including a substrate forming a part of said hermetic package and containing hermetic electrically conductive feedthroughs straight from an inside surface to an outside surface forming electrically conductive pads in a two dimensional grid on said outside surface of said substrate where said outside surface is outside the hermetic package;
providing a flexible electrical circuit having contacts in a two dimensional grid matching said two dimensional grid on said substrate;
applying electrically conductive adhesive to said electrically conductive pads;
applying electrically conductive adhesive to said contacts;
aligning and contacting said electrically conductive pads with said contacts;
curing said electrically conductive adhesive;
underfilling a space between said substrate and said flexible electrical circuit, thereby hermetically sealing said space.
2. The method according to claim 1 , wherein said electrically conductive adhesive includes epoxy and platinum flake.
3. The method according to claim 1 , wherein said substrate forms part of a hermetic package enclosing electronics.
4. The method according to claim 1 , further comprising forming electrodes on an end of said flexible electrical circuit opposite said contacts.
5. The method according to claim 1 , wherein said substrate is an integrated circuit.
6. The method according to claim 1 , wherein the substrate is a rigid substrate.
7. The method according to claim 1 , further comprising forming a circuit on said inside surface of said substrate.
8. A method of making an implantable device comprising:
providing a substrate containing electrically conductive feedthroughs straight from an inside surface to an outside surface forming electrically conductive pads in a two dimensional grid on said outside surface of said substrate;
forming an electrical circuit on said inside surface of said substrate;
bonding a cover to said inside surface of said substrate forming a hermetic package around said electrical circuit configured to be implanted within a human body;
providing a flexible electrical circuit having contacts in a two dimensional grid;
applying electrically conductive adhesive to said electrically conductive pads;
applying electrically conductive adhesive to said contacts;
aligning and contacting said electrically conductive pads with said contacts;
curing said electrically conductive adhesive;
underfilling a space between said substrate and said flexible electrical circuit, thereby hermetically sealing said space.
9. The method according to claim 8 , wherein said electrically conductive adhesive includes epoxy and platinum flake.
10. The method according to claim 8 , further comprising forming electrodes on an end of said flexible electrical circuit opposite said contacts.