A cost-effective, miniaturized and biocompatible packaging method for medical devices is proposed, resulting in a small, soft and comfortable implantable package. Towards this end, the barrier materials and fabrication process for the individual die encapsulation are largely explored. We demonstrate that various common clean room materials are good candidates for preventing metal leaching into body. In accelerated tests at higher temperature, several conductive barrier materials are damaged by the test bio-fluid, suggesting insufficient resistance to body fluids in long term. Covering electrodes by noble metals will solve this problem. For metallization, noble metals as Pt are best candidates. CoO calculations showed that selective plating of Pt is more cost-effective than sputtering. To reduce the cost of a sputter process, Pt recycling is very important.