Copper is well established in electronics due to its good electrical and thermal conductivity. One of its major applications are printed circuit boards (PCBs). PCBs are usually produced by laminating copper foils on a glass fiber reinforced polymer substrate and etching away excess copper with hazardous solutions, resulting in narrow copper lines and a waste of the largest part of the copper material. Therefore, 3D printing of copper becomes an interesting alternative, that offers a more sustainable production method with less waste.

Glass is known for its good dielectric behavior, chemical and thermal stability, optical transparency and relatively good mechanical properties. Embedding copper conductive lines in glass allows protecting them from exposure to various environmental factors, such as solvents or solutions, as well as from mechanical stress. Furthermore, due to its better thermal stability compared to polymers, glass enables elevated working temperatures for the resulting microelectronic devices.

Combined 3D printing of metal and glass can provide an energy and material efficient way for future production methods, but comes along with numerous challenges. These are addressed in the M-ERA.NET research project ‘Coco’, which will be briefly outlined. First results, i.e. the proposal of suitable glass compositions for 3D printing of microelectronic devices and the discussion of their eligibility will be presented.