Electronics Cleaner – Circuit Boards w/ Alodine

A customer needed an electronics cleaner to clean an assembly of a printed circuit board which had been sweat soldered to an aluminum plate/heatsink/carrier. The company needed a detergent that would not attack the Alodine coated aluminum backside or the gold pockets or solder reflowed surface of the circuit board.

Unfortunately, the client’s current electronic cleaner was slightly base ph 9+ and the water slightly alkaline as well coming in at a ph of 8.0.  This, along with other factors, caused staining, darkening and spotty discoloration of the 6061 Alodine coated (chemical conversion coating) aluminum parts.

He needed to clean the parts using a dishwasher and 140F water in a cycle lasting approximately 60 minutes in order to remove water soluble rosin fluxes used in the sweat bonding (soldering of the board to carrier) which loosen up and saponify at 140-160F.

The client once used Alconox in a lab setting and wrote in suspecting that a slightly acidic cleaning solution, or at least one that is buffered to be neutral, would  avoid attacking the aluminum or the Alodine surface.

We recommended a 2% Citrajet solution in a 140 deg F dishwasher.  Citrajet would also allow the parts to pass a avionics required ionic cleanliness test and would ensure long term reliability.

Would you like to try Citrajet or another Alconox detergent in your complex application? Request a free sample by completing the questionnaire at Get Sample.