Circular by design: Investigation of degradable flexible materials for circuit boards

Flexible printed circuit boards are the fastest growing segment of the electronics industry, and they are also among the hardest to recycle. The materials in use today are built to survive everything, which is why the components soldered onto them are never recovered and end up shredded or incinerated together with the substrate. At the IAPP together with the IAVT (Institut für Aufbau- und Verbindungstechnik) we develop bio-based resins that hold up during manufacturing but can be cleaved again under mild conditions so that the components come off intact.

We have successfully made rigid circuit boards which can degrade at the end of their life. Transferring this knowledge to flexible electronics will open up a new way of manufacturing electronic substrates. In this thesis, you will study a series of crosslinkers with cleavable bonding motifs and use them to formulate resins for flexible electronic substrates. The resins and coated boards are then characterized in three directions. First, mechanical flexibility, especially the bending radius over repeated bending cycles. Second, thermomechanical behaviour by DMA, DSC and TGA, including the thermal window relevant for soldering. Third, degradation under mild conditions to recover metals and components. Comparing these three results across the crosslinker series gives us the design rules for the next material generation.

You should be studying chemistry, polymer chemistry or materials science and bring practical experience in lab work. Curiosity about the design of real-world applications such as printed circuit boards are welcome as we are about to spin-out from university with these ideas.

The IAPP is a place where more than 120 physicists, chemists and engineers work together on virtually all topics related to the revolution of green electronics. You will work at the interface between synthesis and device fabrication and see your own material end up on a working circuit board.