Package for an implantable neural stimulation device
An implantable device having a biocompatible hermetic package made from a biocompatible electrically non-conductive substrate and a cover bonded to the substrate. In integrated circuit and passive circuits all bonded directly to the substrate.
1. An implantable device, comprising:
a biocompatible electrically non-conductive substrate;
a plurality of electrically conductive vias through the electrically non-conductive substrate, forming a via substrate;
an integrated circuit attached directly to the via substrate;
discrete passive circuits attached directly to the via substrate to the side of the integrated circuit;
a biocompatible cover brazed to the via substrate with a biocompatible braze, the cover and the via substrate forming a hermetic package;
conductive traces deposited on the via substrate; and
a braze stop on the via substrate and along a periphery of the via substrate surrounding the conductive traces and separating a braze joint from the conductive traces.
2. The implantable device according to claim 1 , further comprising a flexible circuit connected to the via substrate and including electrodes suitable to stimulate neural tissue.
3. The implantable device according to claim 1 , further comprising a polymer body supporting the hermetic package and suitable to be attached to a sclera.
4. The implantable device according to claim 3 , further comprising suture tabs on the polymer body suitable for attaching the polymer body to a sclera.
5. The implantable device according to claim 1 , wherein the cover has convex in profile.
6. The implantable device according to claim 1 , wherein the cover has concave in profile.
7. The implantable device according to claim 1 , wherein the integrated circuit is a flip-chip circuit.
8. The implantable device according to claim 1 , wherein the cover is brazed to the via substrate.
9. The implantable device according to claim 8 , further comprising a braze stop on the via substrate and along a periphery of the via substrate surrounding the conductive traces and separating a braze joint from the conductive traces.
10. The implantable device according to claim 1 , wherein the conductive traces are metal traces.
11. The implantable device according to claim 10 , wherein the metal traces are chosen to withstand braze temperatures.
12. The implantable device according to claim 11 , wherein the metal traces comprise one or more of the metals titanium, tantalum, gold, palladium, platinum or layers or alloys thereof.