Abstract :
Challenges and technologies for long-term stable packaging of implantable devices and microsystems are reviewed. Packaging of implantable microsystems is especially difficult because of the many limitations in terms of size, material properties, mechanical structure and rigidity, biocompatibility, required lifetime, and maximum allowable temperature. Our group has demonstrated their long-term reliability in salt water and biological environments. Glass packages anodically bonded to silicon substrates containing integrated sensors/circuits provide a mean-time-to-failure (MTTF) of >100 years in saline solutions under accelerated conditions, and a lifetime of almost two years in biological tissue1. Thin film coatings of electroplated gold have also been used for packaging of implantable microprobes and shown to be hermetic under accelerated conditions and provide a MTTF of ~40 years. Polymer films, such as Parylene, are of particular interest for many biomedical microsystems because of their flexibility and ease of use. Long-term testing of passive implantable sensors using these films has also been demonstrated.
Keywords :
micromechanical devices; packaging; prosthetics; reliability; biological environment; electroplated gold; glass packages; implantable devices; implantable microprobes; implantable microsystems; integrated circuits; integrated sensors; long-term reliability; packaging; salt water environment; thin film coatings; Acceleration; Biosensors; Bonding; Glass; Integrated circuit reliability; Material properties; Packaging; Polymer films; Silicon; Temperature sensors;
