Abstract
Polymer materials attract more and more interests for a biocompatible package of novel implantable medical devices. Medical implants need to be packaged in a biocompatible way to minimize FBR (Foreign Body Reaction) of the implant. One of the most advanced implantable devices is neural prosthesis device, which consists of polymeric neural electrode and silicon neural signal processing integrated circuit (IC). The overall neural interface system should be packaged in a biocompatible way to be implanted in a patient. The biocompatible packaging is being mainly achieved in two approaches; (1) polymer encapsulation of conventional package based on die attach, wire bond, solder bump, etc. (2) chip-level integrated interconnect, which integrates Si chip with metal thin film deposition through sacrificial release technique. The polymer encapsulation must cover different materials, creating a multitude of interface, which is of much importance in long-term reliability of the implanted biocompatible package. Another failure mode is bio-fluid penetration through the polymer encapsulation layer. To prevent bio-fluid leakage, a diffusion barrier is frequently added to the polymer packaging layer. Such a diffusion barrier is also used in polymer-based neural electrodes. This review paper presents the summary of biocompatible packaging techniques, packaging materials focusing on encapsulation polymer materials and diffusion barrier, and a FEM-based modeling and simulation to study the biocompatible package reliability.
Highlights
This paper presents polymer-based biocompatible packaging techniques for implantable devices
Conventional crack has been dealt in assumption that the material is homogeneous, but packaging for electronics or implantable device should be considered as non-homogeneous materials, creating different interfaces
Evolution of the biocompatible packaging has been recently reported; it has been recognized that flip-chip bonding with a bare chip is one of best way of packaging in terms of miniaturization as is conventional electronics packaging
Summary
Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Emergence of new implantable devices such as retina prothesis requires an innovative packaging as conventional wire-bonding techniques would not be applicable to implement massive electrical interconnect, for example, 1000 electrodes (see Figure 1d) [23]. In this case, technological barrier exists in substantial scale difference between Si chips and polymeric stimulation device for mechanical interconnection. Thinned Si IC can be embedded into polymer material and it can be integrated with the polymer-based neural prothesis Such a thin silicon chip is ideally best approach to achieve maximum miniaturization of an active implant.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
