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, 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 device comprising:
a substrate at least a portion of which is electrically conductive and forms at least a portion of a hermetic package;
a flexible assembly at least a portion of which is electrically conductive; and
at least one area of deposited platinum forming a rivet shaped connection that bonds the substrate and the flexible assembly.
2. The implantable device according to claim 1 , wherein the area of deposited platinum is greater than one micron thick.
3. The implantable device according to claim 1 , wherein the area of deposited platinum has a Vickers hardness greater than ten.
4. The implantable device according to claim 1 , wherein a biocompatible adhesive further bonds the substrate and the flexible assembly.
5. The implantable device according to claim 1 , wherein the area of deposited platinum is formed by electrochemical deposition.
6. The implantable device according to claim 1 , wherein the flexible assembly comprises polyimide.
7. The implantable device according to claim 1 , wherein the substrate comprises a biocompatible ceramic.
8. The implantable device according to claim 7 , wherein the biocompatible ceramic comprises alumina.
9. The implantable device according to claim 1 , wherein the substrate is rigid.
10. The implantable device according to claim 1 , wherein the substrate is an electrically insulated integrated circuit.
11. The implantable device according to claim 1 , wherein the flexible assembly is a thin film integrated circuit.
12. The implantable device according to claim 1 , wherein at least a part of the substrate forms an electronics control unit; and the electronics control unit encapsulates electronics.
13. The implantable device according to claim 1 , wherein the area of deposited platinum does not contain lead.
14. The implantable device according to claim 1 , wherein the area of deposited platinum consists essentially of pure platinum.