Lead-Free Soldering: Challenges with SAC Alloy

After the mandatory switch from leaded to lead-free soldering (already about 20 years ago!), the most commonly used solder alloy is SAC (Tin Silver Copper). Its melting temperature is 217-219 degrees.

This high temperature isn't always ideal. Especially 'hand soldering old style' (with lead) is attractive for prototypes and small experiments. To stay within lead-free alloys, we're now investigating a SAC with added Indium. This lowers the melting point (around 200 degrees) and also further reduces brittleness. The alloy we're researching is widely used in consumer electronics (mobile phones) and has more than proven itself there.

Because we prefer to use water-soluble solder flux (this makes rework and experimentation easier), we're in discussions to start using Water Soluble SAC-Indium in addition to No Clean 200 SAC-Indium.

Especially for ProtoPCBA's that still need small modifications, a lower melting temperature can be convenient. At an industrial level, using this new solder also provides energy savings of up to 20%.

A nice bonus, we think...

HappyEngineering