Anisotropic conductive film & flip-chip bonding for low-cost sensor prototyping on rigid & flex PCB

Stoukatch, Serguei [Microsys lab, Department of Electrical Engineering and Computer Science, Liege University, Seraing, Belgium] André, Nicolas [UCL] Delhaye, Thibault [UCL] Dupont, François [Microsys lab, Department of Electrical Engineering and Computer Science, Liege University, Seraing, Belgium] Redouté, Jean-Michel [Microsys lab, Department of Electrical Engineering and Computer Science, Liege University, Seraing, Belgium] Flandre, Denis [UCL]

We developed a low-cost process for assembling versatile sensors without expensive, thick metal finish on rigid and flexible PCB using anisotropic conductive films (ACF) flipchip (FC) process. This allows a lower temperature budget than conventional FC assembly. The ACF FC process requires no expensive set up, is quick to implement and suits perfectly for sensor prototyping and low-scale manufacturing. The process was directly applied to assemble the bare die of a CMOS strain gauge sensor on flexible PCB without compromising its integrity.