I've worked with piezoelectric devices for well, a long time, and the holy grail has always been some means of electrical connection without heating them up, which can create an inactive area or start mechanical flaws. Silver loaded epoxies can work in many cases, but the conductivity is nowhere near as good as solder. It doesn't work well for low voltage high current multi-layer devices. There are some other techniques with their own peculiarities, but this one actually looks very promising. How one would apply it to conventional PCB based electronics is anybodies guess, and repair doesn't look like an option, but nothing gets repaired anymore anyway.