Sn100C - anyone use this at Reflow?

We're using Sn100C at wave. Well, to be fair, in a static solder pot; as we don't have a lead-free wave machine in operation at the moment.

We've had generally good experiences with the SN100. Good soldering; some blow holes, but, since we're using a static pot, I'm not sure how much to attribute to that vs. the material.

When we add a lead free machine, our plan is to use SN100 as well.

cheers ..rob

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There are many users of SN100C in reflow. SN100C was originally introduced as a wave solder alloy which offered cost savings over SAC, no solder pot erosion, and high fluidity. Since it is eutectic, no plastic range, the joints have a smooth, shiny surface similar to Sn/Pb. It has been found that the high fluidity is an advantage in reflow although the melting point (227C) is higher than SAC. The negative you asked about is if there is a large delta T across the board. This can be an issue in reflow as the concern is not to over heat a small component while reflowing a large, thermally challenging component due to the slightly higher melting point. However, this issue is minimal as most users use the same profile as they did for SAC. Many users use SN100C for selective due to the fluidity which allows the use of small diameter nozzles and the low copper dissolution that it offers. Dwell times can be longer if needed without eroding away the pads. The high fluidity is also a benefit in hand soldering as it easily flows.

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