Novel Connector Mechanism Using Anisotropic Conductive Rubber for Trillion-Node Engine as an IoT Edge Platform

Abstract

An IoT edge platform, where desired IoT nodes are realized selecting and connecting several single-function printed circuit boards (PCBs) such as a sensor, microprocessor, and power supply unit with anisotropic conductive rubber (ACR) connectors, is demonstrated. The PCBs are called “leaf PCBs” and their dimensions are typically $\mathrm{2}\ \text{cm}\times \mathrm{2}\ \text{cm}$. Small rubber connectors are employed to connect these PCBs so that soldering is unnecessary and removable and replaceable structure is realized for customizability of IoT nodes. A wire connection mechanism is also developed to connect wires between leaf PCBs and external devices such as motors and sensors. It is smaller than conventional terminal blocks. To investigate important performance of the proposed connection schemes, temperature cycle tests for ACR connectors and retention strength tests for wire connection mechanisms are carried out.