Implant encapsulation
An implant unit may include a substrate and an implantable circuit arranged on the substrate. An encapsulation structure may be disposed over at least a portion of the substrate and at least a portion of the implantable circuit, the encapsulation structure including a parylene layer and a silicon layer disposed over the parylene layer.
1. An implant unit, comprising:
a substrate;
an implantable circuit arranged on the substrate; and
an encapsulation structure disposed over at least a portion of the substrate and at least a portion of the implantable circuit, the encapsulation structure including:
a first polymer layer having a first density;
a second polymer layer disposed over the first polymer layer and having a density which is less than the first density; and
at least one pair of modulation electrodes connected to the implantable circuit, wherein the first polymer layer includes a first window of exposure over one or more of the modulation electrodes, the first window of exposure having a first area; and
wherein the second polymer layer includes a second window of exposure over one or more of the modulation electrodes and at least partially extending over the first window of exposure, the second window of exposure having a second area that is larger than the first area of the first window of exposure.
2. The implant unit of claim 1 , wherein the first polymer layer includes parylene and the second polymer layer includes silicone.
3. The implant unit of claim 2 , wherein the parylene includes parylene C.
4. The implant unit of claim 1 , wherein the substrate comprises a flexible carrier.
5. The implant unit of claim 1 , further comprising an antenna encapsulated by the first polymer layer and the second polymer layer.
6. The implant unit of claim 1 , wherein the implantable circuit includes at least one meandering electrical trace configured to maintain electrical contact during flexing of the device.
7. The implant unit of claim 1 , wherein the substrate includes at least one perforation, and wherein the second polymer layer is disposed on a first side of the substrate, on a second side of the substrate opposite to the first side, and through the at least one perforation.
8. The implant unit of claim 1 , further comprising at least one suture hole through the substrate and the second polymer layer and a surgical mesh disposed within the at least one suture hole, wherein the surgical mesh is encapsulated by the second polymer layer.
9. The implant unit of claim 1 , further comprising at least one suture hole through the substrate and the second polymer layer.
10. The implant unit of claim 1 , wherein the device has a thickness of less than 4 mm.
11. The implant unit of claim 1 , wherein the first polymer layer is deposited by chemical vapor deposition.
12. The implant unit of claim 1 , wherein a thickness of the first polymer layer is between 10 microns and 80 microns thick.
13. The implant unit of claim 1 , wherein the substrate includes a flexible carrier.
14. The implant unit of claim 13 , wherein the flexible carrier has a thickness of less than about 4 mm.
15. The implant unit of claim 13 , wherein the flexible carrier includes at least one of silicone, polyimides, phenyltrimethoxysilane, polymethyl methacrylate, Parylene C, polyimide, liquid polyimide, laminated polyimide, black epoxy, polyether ether ketone, Liquid Crystal Polymer, or Kapton.
16. The implant unit of claim 1 , further including a third polymer layer disposed over the second polymer layer, wherein the third polymer layer has a density less than the second polymer layer.
17. The implant unit of claim 1 , wherein the third polymer layer includes parylene.