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 studbump 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 hermetic electronics control unit including a bond pad,
a first thin film flexible electrically insulating substrate;
an electrically conducting metal layer deposited on the first insulating layer;
a second thin film flexible electrically insulating substrate deposited on the electrically conducting metal layer;
at least one of the first flexible electrically insulating substrate or the second flexible electrically insulating substrate defining a hole that expose the electrically conducting metal layer forming a contact; and
an electrically conductive studbump for bonding the bond pad to the contact.
2. The implantable electronic device according to claim 1 , wherein the stud bump is comprised of platinum or a platinum alloy.
3. The implantable electronic device according to claim 1 , wherein the stud bump is comprised of gold or a gold alloy.
4. The implantable electronic device according to claim 1 , further comprising under fill surrounding the studbump.
5. The implantable electronic device according to claim 1 , further comprising plating to thicken the bond pad.
6. The implantable electronic device according to claim 1 , further comprising plating to thicken the contact.
7. The implantable electronic device according to claim 1 , wherein the each half of the studbump is flattened by coining.
8. The implantable electronic device according to claim 1 , wherein the studbump is bonded by ultrasonic energy.
9. The implantable electronic device according to claim 1 , wherein the studbump is bonded by diffusion.
10. The implantable electronic device according to claim 1 , wherein the studbump is bonded by thermosonic bonding.
11. The implantable electronic device according to claim 1 , wherein the studbump is bonded by thermocompression bonding.