Interposers: A Central Generic Technology for IoT

Abstract

Also sometimes referred to as 2.5D integration, interposers are now a true and important component of the “3D world” based on die stacking technologies. Considered as an intermediate step in the field of high density die stacking (memory on logic, logic on logic, etc) this technology is on the other hand fully generic to manufacture heterogeneous systems which will constitute the basic of IoT (sensor with simple logic, RF capabilities and even energy harvesting). This paper presents first a short overview of the core technologies needed in this field. The versatility of these technical blocks, allowing to efficiently manufacture a large variety of interposer based devices, is then demonstrated through different subsystems related to IoT: sensors, passives, energy harvesters, RF communication. Some recent achievements in smart systems based on interposers mixing together passive components, microsystems and RF functions are then presented, and more particularly a system dedicated to short range high bandwidth communication for wireless HDMI and a system for implanted medical applications. In both cases, the gain in surface area is particularly important, making such solutions highly attractive.