Newly developed integration method for biomedical implants using flexible polymer cable

This paper presented an integration method for biomedical implants by using solder bonding and highly flexible polyimide (PI) cable. The proposed integration method can overcame the problems in flexible cable assembly before. It can achieve a small form, and better reliability, and is easier for fragile MEMS device bonding by using solder bonding. Therefore, it is suitable for various MEMS devices integration. The effect of the metal materials and reliability of the flexible cable with thin metal trace were studied. SEM and TEM/EDX analysis were performed to evaluate the boning interface microstructures. Electrical tests were carried out to study the resistance of the interconnects. Thermal cycling test with temperature range of -40/+125°C with 15mins dwell for 500 cycles was used to evaluate the reliability properties of the interconnects. The results showed good bonding interface, low electrical resistance and there were no major changes in resistance during thermal cycling. Hence, it implied that the interconnections were highly stable and reliable by using the proposed bonding method.