Impact of no-clean fluxes cleaning on PCB ionic contamination

The paper describes the dependence of the ionic contamination of PCB after the soldering process with no-clean solder pastes on the type of cleaning. For the experiment three different types of solder paste were selected. Solder pastes were labeled as no-clean. The samples were reflowed with two different soldered profiles. The ionic contamination after soldering process was measured. Contamination of PCB was investigated to set up of solder profile. Then three different types of rinses were applied to the samples. The rinsing medium was deionized water, 50 % deionized water with 50 % isopropyl alcohol (IPA) and IPA. The cleaning process was set to 10 minutes in an ultrasonic cleaning bath. Then rate of ionic contamination after application of cleaning the PCB were monitored. From the results there were determined by a recommendation on whether it is necessary to clean no-clean solder paste.