Biocompatible electroplated interconnection electronics package suitable for implantation
Device is a hermetically sealed electronics package bonded to an electrode or flexible circuit that is suitable for implantation such as for a retinal or cortical electrode array. The hermetically sealed electronics package is bonded to the electrode or flexible circuit by electroplating a biocompatible material, such as platinum or gold, forming a plated connection, bonding the flexible circuit to the electronics package. The resulting electronic device is biocompatible and is suitable for long-term implantation. The device comprises a substrate containing a contact, a flexible assembly containing a pad, and electroplated bonding between said contact and said pad that bonds said substrate and said flexible assembly together.
1. An electronics device comprising:
a substrate containing at least one contact;
a flexible assembly containing at least one bond pad defining an opening;
an electroplated bonding between said at least one contact and said at least one bond pad and through said opening that forms a rivet shaped bond between said substrate and said flexible assembly together;
said electroplated bonding comprised of biocompatible material comprising platinum or gold; and
said biocompatible material having a first dense layer of platinum or gold said contact and a second less dense layer of platinum or gold to reduce internal stresses and increase the strength of the rivet shaped bond on said first dense layer;
wherein the first dense layer and the second less dense layer consist of the same elemental composition.
2. The device according to claim 1 wherein said device is implantable.
3. The device according to claim 1 wherein said contact is a routing.
4. The device according to claim 1 wherein said electroplated bonding comprises platinum alloy or platinum-iridium.
5. The device according to claim 4 wherein electroplated bonding is accomplished at a current density of 0.5 to 40 mA/cm 2 .
6. The device according to claim 1 wherein said flexible assembly comprises polyimide.
7. The device according to claim 1 wherein said substrate comprises a biocompatible ceramic bonded to an integrated circuit with a hermetic coating.
8. The device according to claim 7 wherein said biocompatible ceramic comprises alumina.
9. The device according to claim 1 wherein:
at least a part of said substrate forms an electronics package; and
said electronics package encapsulates electronics.
10. The device according to claim 1 wherein said substrate is an electrically insulated integrated circuit.
11. The device according to claim 1 wherein said flexible assembly is a thin integrated circuit with a hermetic coating.
12. The device according to claim 1 wherein:
said biocompatible metal is comprised of gold or platinum; and
said biocompatible gold or platinum having a first dense layer that is formed with a plating voltage and a second less dense layer that is formed at a higher plating voltage with increased deposition rate.