Micro-hybrid system in polymer foil based on adaptive layout

The micro-hybrid system in foil (HySiF) involves ultra-thin chips embedded and interconnected in polymer foil for diverse flexible electronic applications. In this paper, the concepts and results of wafer level embedding and interconnection of ultra-thin dies in polymers are presented. The significant achievement of the presented HySiF is the accurate interconnection between a pair of functional chips at wafer level based on an adaptive interconnect layout, thus allowing for a small wire pitch on and off the chip. As a result, contact pads can be abandoned from the chip, which leads to reduced silicon area and, thus, lower cost. In addition, misalignment of embedded chips can be compensated by the adaptive layout, thus allowing for far higher I/O count. In this paper, this novel embedding technique is demonstrated with a metal pitch less than 108 μm and for a pair of functional chips spaced in the range of 200-1000 μm.