SMD Soldering Practice

Today I hot air soldered my first SMD components. I used an Aoyue 2702A+ rework station. This is a cheap unit that "does it all". So far I am pretty happy with it, except that it had a very strong chemical odor when I unpacked...I kept it in the garage for a few days for outgassing. Now it got better, but it is still noticeable. Anyway, on to the SMDs!

I used 14 mcd LEDs from Lumex (SML-LX 0603IW-TR) for this test. They seem to be of similar brightness as the 1982 LEDs that are in my Beomaster 7-segment displays, and they have a very small package, i.e. should hopefully fit into the diffusers of the displays. For practicing and testing I used a "Surfboards" SMD breadboard for using SMDs on a standard wire component breadboard. On the picture the final result is shown. Even though this does not look perfect, they all worked. I used a low temperature solder paste, the lowest airflow setting (10) and a restricting 3 mm diameter nozzle on the blower tool. Temperature was set to 178C (the solder paste apparently already melts at 138C....). The entire process was surprisingly easy. The only real difficulty being not to blow the LEDs from the board while heating the paste up. Surface tension seems to put everything in place 'automatically' when the paste is hot enough.