SU-8 flexible ribbon cable for biomedical microsystem interconnection

The paper presents a flexible interconnecting scheme with a wafer-level process to fabricate a SU-8 flexible ribbon cable for biomedical microsystem interconnection. Combining with a low temperature Au-Au thermocompressive bond (<;200°C), the cable with 40 metal lines can provide mechanical and electrical connections between biomedical probes and external circuit chips. ~3.3 MPa shear bonding strength can be achieved between the contacts formed on a silicon based microprobe and the ribbon cable, respectively. Meanwhile, ~8.82×10^-7 Ω·cm² specific contact resistance has been measured between the contacts formed on the SU-8 and CMOS substrates, respectively. The experimental results have shown potential applications of the flexible interconnecting scheme for the heterogeneous integration of biomedical microsystems.