On Thu, 14 Dec 2006 17:01:11 -0500, Brian Guralnick wrote: >> And a bit of hard won experience. Avoid "no-clean" flux, it will >> leak at high humidity. It is only to be used at less than 100 V. >> >> Regards, >> --Paul >> > > I've measured no-clean flux leakage variance with voltages as low > as 2v. It was a regulated supply for a battery powered project & > the no-clean flux was conducting a number of pico-amps which varied > from day-day. I was only able to solve the problem after "massive" > number of cleaning & scrubbing cycles. Even with visual analysis > with a microscope, you could not tell the difference before & after > the cleaning, and yet, there was a significant measureable > difference in effect.
Yeah-but...(tm) the sales guy and literature said the no-clean flux is non-conductive! ;-) I've had problems with no-clean flux causing very high impedance crystal oscillator circuits starting (32KHz clock on MSP430 microcontrollers) when the humidity is high. I've also found that the residue also attracts other impurities (which of course stick to the flux residue) that also add to the problems over time. Other than that, I think the residue looks ugly too, but some people don't mind. Problems were solved by going to a aqueous flux and mil-spec wash process for production items. No-clean looks good on paper, but for a lot of applications it can cause some real problems. I generally avoid it whenever I can. Matt Pobursky Maximum Performance Systems ____________________________________________________________ You are subscribed to the PEDA discussion forum To Post messages: mailto:[email protected] Unsubscribe and Other Options: http://techservinc.com/mailman/listinfo/peda_techservinc.com Browse or Search Old Archives (2001-2004): http://www.mail-archive.com/[email protected] Browse or Search Current Archives (2004-Current): http://www.mail-archive.com/[email protected]
