A new "metal-based glue" is supposedly able to match some properties of w elded and soldered joints, but without heat:
It's kinda sketchy on details but AIUI it's a two-component system. One c ontains indium, the other gallium. Upon contact, with a little pressure app lied, they melt together, then solidify. The joint is thermally and electri cally conductive and gas/liquid-tight. The article doesn't say just *how* c onductive, of course, or what metals it works on, but if it's cheap enough it could eliminate reflow soldering (and associated cleanup) in board produ ction frinst. Pick-and-place would become pick, place, and push.
Mark L. Fergerson