So far, I've found little information about recommended cleaning processes. I'd rather not invest in a $40k+ defluxer at our volumes. One SMT equipment re-seller says a dishwasher works great, as long as you adhere to local water regulations. Seriously?
Several of our boards require 0.1% thin film resistors. DigiKey briefly explains:
In the few instances I've had to wash these boards by hand, compressed air was not sufficient to dry them. Every resistor must be subjected to 250C+ heat from a hot air rework station. That's fine when we're handling 1 or 2 boards. Drying a batch of 500 boards this way could take all day...In addition, thin film resistors (except for the RNCS and HDM) are susceptible to moisture if operated under extremely humid conditions at low power loading.
Has anyone dealt with similar moisture sensitive parts before? Could we simply bake the boards again in the oven, at a lower temperature (after cleaning)?