The medical industry is clearly and urgently in need of development of advanced packaging that can meet the growing demand for miniaturization, high-speed performance, and flexibility for handheld, portable, in vivo, and implantable devices. To accomplish this, new packaging structures need to be able to integrate more dies with greater function, higher I/O counts, smaller die pad pitches, and high reliability, while being pushed into smaller and smaller footprints. As a result, the microelectronics industry is moving toward alternative, innovative approaches as solutions for squeezing more function into smaller packages. This paper discusses the development of advanced packaging that can meet the growing demand for miniaturization, high-speed performance, and flexibility for miniaturized electronic devices. In particular, recent developments in high density interconnect (HDI) substrate technology are highlighted. System-in-Package (SiP), embedded passives, stacked packages, and flex substrates are utilized to achieve significant reduction in size, weight, and power (SWaP) consumption in electronic devices. The paper also describes a novel approach for the fabrication of silicone-coated flexible substrates to provide biocompatibility for implantable devices. In particular, we highlight recent developments on silicone coatings on high density, miniaturized polyimide-based flexible electronics. A variety of high density circuits ranging from 11 microns lines/space to 25 microns lines/spaces were processed on polyimide flex substrates and subsequently coated with biocompatible silicone coatings. The electrical performance of silicone coated batteries was characterized by voltage measurements. The final structure enhances the stretching capability. Fabrication of advanced medical substrates incorporating technologies for parts authentication (anticounterfeit measures) such as embedded signature circuits and use of nano or micro materials as signatures are discussed. In some instances, these measures do not add cost to package fabrication.
Broad-Band Electrical Conductivity of High Density Polyethylene Nanocomposites with Carbon Nanoadditives: Multiwall Carbon Nanotubes and Carbon Nanofibers
