In my previous question I focused on lead-based solder alloys (see Best solder wire - Sn63Pb37 vs Sn60Pb40 vs ...?).

Some of you brought new exciting solder alloys to my attention. The two most promising types contain either Bismuth or Indium.

Some questions:

• How do they compare to each other on properties like:

  • wetting of pads and pins
  • interaction with fluxes
  • joint strength - brittleness
  • price
  • ...

• How do they compare to standard solder alloys, like Sn60Pb40?

• Any drawbacks?

• Most of them are sold without flux core. Wouldn't that make the solder process very difficult?

• What kind of flux should one use with Bismuth and/or Indium based solders?