Fine-Pitch Bonding Methods for Integrating Asics with Flexible Polymer Mems

摘要

We developed and adapted multiple robust, high-yield processes to achieve fine-pitch bonding of application specific integrated circuit (ASIC) chips directly into flexible polymer MEMS constructed using Parylene. These methods were developed to integrate circuits that perform multiplexing, amplification, and signal processing functions to achieve large scale, high-density neural probe arrays to record from the brain (Figure 1) and have broad application to other flexible electronic devices. Bonds were achieved using wedge bonding, conductive epoxy, anisotropic conductive film (ACF), and a novel polymer ultrasonic on bump (PUB) technique at both low temperature (≤ 100 °C) and fine pitch (100 µm), all with yields of 83% or greater. Bonded devices were subjected to a battery of thermal and mechanical tests based on industry standards, demonstrating robustness and reliability.