A question for the soldering experts: A customer wants a PCB to soldered with leaded solder. In principle this should be no problem, we have done this in the past without any problems. Just use conventional solder and run at the appropriate temperatures. The RHoS components will not complain when they are not heated up so much during soldering. Leaded solder will wet the pins just fine.
But this time we have a BGA which is only available in RHoS version. This means the solder balls below the BGA are lead-free solder. What temperature to use? The solder balls should melt, so we would need higher temperature. What will happen when leaded solder paste and lead-free solder from the balls mixes? Any problems to expect?