Empa develops biodegradable printed circuit boards

(CONNECT) Empa is working on the development of a green alternative to printed circuit boards as part of the EU research project HyPELignum. A group of researchers led by Thomas Geiger from the Cellulose and Wood Materials laboratory at the research institute has succeeded in developing a carrier material based on wood that could be used instead of the epoxy resin conventionally used for printed circuit boards, Empa reports in a press release. In contrast to the non-recyclable epoxy resin, which is expensive to dispose of, the carrier material made from lignocellulose is completely compostable.

Lignocellulose is also a waste material that is produced during the extraction of lignin and hemicellulose from wood. At Empa, the flaky lignocellulose is processed into fine fibrils, which are then pressed into a solid mass. The resulting boards are almost as resistant as printed circuit boards made of glass fibers and epoxy, but are sensitive to water and high humidity.

This must also be maintained to a certain extent, because "if water can no longer penetrate the carrier material, microorganisms such as fungi can no longer grow in it," explains Geiger in the press release. "And that would make it no longer biodegradable." In the next step, the researchers are therefore working on improving the resistance of the material without jeopardizing its compostability. The metallic and electronic components soldered onto the circuit board can be removed from the compost and recycled after the carrier material has decomposed. ce/hs