I worked at a large Computer Company in Cupertino, and we used Water Soluble Flux, Then washed the Boards in a Dishwasher, with Water. Open Air Drying to keep water from Wicking into any Parts.
Ray WA6VAB Engineering. K3 From: Hal Massey Sent: Sunday, January 2, 2022 9:11 AM To: Jim Bruce Cc: elecraft@mailman.qth.net Subject: Re: [Elecraft] Cleaning solder flux In an SMT production facility that was in the home city of Elecraft (Watsonville, CA) we went to aqueous wash very early on. I was on the design engineering side in Cupertino, CA but I can probably connect with some of those Manufacturing Engineers. I remember it well because the design side had to select components that would allow for this. This was the former Tandem Computers, Inc. manufacturing line. The company’s president and founder was Jimmy Treybig- W6JKV. > On Jan 2, 2022, at 9:47 AM, Jim Bruce <jimw...@gmail.com> wrote: > > In all of the places I worked beginning with the Air Force we used > isopropyl alcohol to remove flux from repairs on boards with the exception > of one. At I believe General Radio(GenRad) in Rockville, Md we used banana > oil for flux removal. > > Has anyone else used something other than alcohol?? > > Jim/W3FA > > On Sun, Jan 2, 2022, 10:13 Dr. William J. Schmidt <b...@wjschmidt.com> > wrote: > >> During my under-graduate and graduate school careers, I worked at >> Honeywell's circuit board fabrication shop for about a year and a half. We >> had two machines in the shop that dealt with flux: a reflow machine and a >> parts set machine. The reflow machine was used to reflow the solder after >> plating so that it looked shiny. The board was emersed in a 601-type flux, >> heated to about 425F, cooled down, and then scrubbed (brushed) with >> Isopropanol alcohol three times (stages) with a water rinse and force-air >> dried (all automagically). The solder was beautiful and shiny at the end >> of >> this process. The parts-setting machine was similar... the whole >> (pre-reflowed) board was fluxed, the parts set, heated, and then cleaned. >> All fluxes come off with Isopropanol alcohol (remember IPA is polar like >> water and works that way). >> >> >> >> Fluxes come in various forms... some are more corrosive and some not... so >> you should follow the directions (right off the website). Rosin can remain >> on a board, but also can be problematic because it can collect debris (dust >> and other unwanted materials) because its plastic (flows at room >> temperature) sticky. Many of the water-soluble fluxes are more acidic, and >> will tarnish the solder joints if not removed. >> >> >> >> On the subject of using water on electrical components... most components >> (particularly if they might be mil spec) are made for water emersion (NOT >> ALL!). In my office lab we routinely clean circuit boards by scrubbing >> them >> with just water and force-drying them. Works fine. About a decade ago, I >> used to buy up surplus AM/ broadcast band transmitters for repurposing to >> other countries (mainly south America) for the Christian broadcasting >> markets. Once back at my shop, the first stop was a good through power >> washing in the driveway (paper and other water damaged goods removed of >> course) followed by a good drying (leaf blower). Works fine! >> >> >> >> >> >> Dr. William J. Schmidt - K9HZ J68HZ 8P6HK ZF2HZ PJ4/K9HZ VP5/K9HZ PJ2/K9HZ >> VP2EHZ >> >> >> >> >> >> -- >> This email has been checked for viruses by AVG. >> https://www.avg.com >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to jimw...@gmail.com >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to haljr.mas...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to wa6...@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
