This is a very old problem. You have what is known in the trade as wet boards. In other words, there is moisture trapped in the PCB laminate. This is typical of poorly manufactured boards. Do you have plated through holes? If so the plating quality is suspect too.
The simple solution is to bake your boards before soldering. Use an oven set somewhere between 105 to 120C for 4 hours. Any hotter and you will damage the resin coat. Fred Townsend Alexandre Souza wrote: > > I have basically no manufacturing experience, I should say. The board > > had a soldering problem - poor preheating. Small stuff was soldered OK, > > but (a lot of) physically large parts were underheated, and soldering > > was poor. Ditto for the earth line, and thick tracks. So far so good. > > When I reheated these joints, they started bubbling, and continued > > bubbling. They would spit solder away on occasion. I had to be careful > > not to overheat compontents, But this would continue for 30 secs on a > > pin, and I gave up before it did. Certainly more than flux. > > What's going on?? Implications?? > > Seems poor soldering/poor quality solder. There is no best solution than suck > the old > solder and apply new solder. This is a very common problem in Brazil with computer > monitors made by TCE here. > > http://www.pinball-taito.com.br/amiga/howtofix.htm will show you some examples of > "good" TCE soldering job ;o) > > Greetings from Brazil! > > --- > Outgoing mail is certified Virus Free. > Checked by AVG anti-virus system (http://www.grisoft.com). > Version: 6.0.537 / Virus Database: 332 - Release Date: 07/11/03 > > -- > Author: Alexandre Souza > INET: [EMAIL PROTECTED] > > Fat City Network Services -- 858-538-5051 http://www.fatcity.com > San Diego, California -- Mailing list and web hosting services > --------------------------------------------------------------------- > To REMOVE yourself from this mailing list, send an E-Mail message > to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in > the message BODY, include a line containing: UNSUB CHIPDIR-L > (or the name of mailing list you want to be removed from). You may > also send the HELP command for other information (like subscribing). -- Author: Fred Townsend INET: [EMAIL PROTECTED] Fat City Network Services -- 858-538-5051 http://www.fatcity.com San Diego, California -- Mailing list and web hosting services --------------------------------------------------------------------- To REMOVE yourself from this mailing list, send an E-Mail message to: [EMAIL PROTECTED] (note EXACT spelling of 'ListGuru') and in the message BODY, include a line containing: UNSUB CHIPDIR-L (or the name of mailing list you want to be removed from). You may also send the HELP command for other information (like subscribing).
