SMT Soldering Notes

The equipment room has a surface mount soldering kit that uses hot air. There is solder paste kept in the e.r.'s refrigerator. These are some preliminary notes for using the Airbath, board holder, pintpoint tool and solder paste to solder surface mount parts onto printed circuit boards. To begin, set the board up on the black metal framed board holder. Then put the Airbath directly underneath, so that it will warm the whole board evenly.

1. While board is cold, apply solder paste sparingly to all pads.
2. Place all components, pressing lightly down into paste and aligning as accurately as possible.
3. Heat board over Airbath to 205 degrees Celsius.
4. Set SMT Pinpoint Soldering System to maximum temperature and lowest airflow.
5. Hold SMT pinpoint tool directly above first component and very very slowly bring it downwards until solder begins to flow slightly, then back off a bit and let the heat flow the rest of the solder without getting close enough for the air to blow away the part. Takes a bit of practice but it works nicely even with the tiny 0603 components. The surface tension of the solder pulls the parts into alignment fairly well.
6. Repeat step 5 for each component, then cool the Airbath and inspect all the parts.

Initially developed by Rob Faludi. Please add your improvements and comments about this method if you try it.