What material is used for the PCB traces?
There are also &quot;aluminum trace PCBs&quot; (to differentiate from &quot;aluminum base PCB&quot;, which use aluminum as a heat-sinking backplane) but they are more expensive than copper PCBs.
It serves a very niche market: superconducting traces for cryogenic electronics, transparent PCBs for X-ray systems, PCBs with long radiation length materials for nuclear beam applications.
Pro: very good for aluminum wire bonding.
Con: it is difficult (although possible) to solder to aluminum using fluxes based on fluoroborate. However, it is also possible to have copper plated into the aluminum to make it easily solderable.