Here is the abstract you requested from the IMAPS_2012 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|Biocompatible encapsulation and interconnection technology for implantable electronic devices|
|Keywords: biocompatible packaging, electronic implants, biocompatible interconnects|
|A biocompatible packaging process for implantable electronic systems is under development at imec, combining biocompatibility, hermeticity, extreme miniaturization and cost aspects. In a first phase of this packaging sequence, hermetic chip sealing is performed by encapsulating all chips to realize a bi-directional diffusion barrier preventing body fluids to leach into the package causing corrosion, and preventing IC materials such as Cu to diffuse into the body, causing various adverse effects. For cost effectiveness, this chip sealing is performed as post-processing at wafer level, using modifications of standard clean room (CR) fabrication techniques. Well known conductive and insulating CR materials are investigated with respect to their biocompatibility, biostability, diffusion barrier properties and sensitivity to corrosion using a series of tests such as cell cultures, extractions and corrosion tests at 37C and at elevated temperatures, and analysis of extracts. Material selection and integration aspects are modified until good properties are obtained. In a second phase of the packaging process, all chips of the final device should be electrically connected, applying a biocompatible metallization scheme. We selected the use of Pt due to its excellent biocompatibility and corrosion resistance. Since Pt is very expensive, a cost effective Pt-selective plating process is developed. During the third packaging step, all system components such as electronics, passives, a battery,... will be interconnected. Parylene-C is used as biocompatible protecting device polymer to protect the device for moisture penetration. To provide sufficient mechanical support, all components are finally embedded using a medical grade elastomer such as PDMS or Poly-urethane. Such a soft elastomer will also reduce the body reaction upon implantation due to its biomimetic nature (flex, soft material cfr. tissue). A final functional coating to provide the device with additional functionalities can be used, such as an antimicrobial coating or a drug-containing biodegradable coating.|
|Maaike Op de Beeck, Program Manager HUMAN++