The PCB market competition is fierce in today's case, the production technology is to create a fastdelivery, reduce costs, improve the quality of one of the main ways, explain two PCB production processoften appear here, and many businesses don't know how to improve the problem.
A, PCB production process, photosensitive solder mask black, white oil, often developing after the surfacewith a layer of black, white, ash, dust-free paper can be rubbed off.
Similar problems have seen ten circuit board factory, each called to ask who is said to be pre-roast whendied, causing treatment, dirty, they usually shorten the baking time to solve this problem, the result isjust the opposite. And ask that they baking sheet conditions mostly at 75 ℃ * 25-35 minutes, double-sidedand printed.
As PCB factory welding room competent should can itself solution such of problem, and most simple of problem often was didn't technology of people more make more bad, had see had a PCB manufacturers welding room competent in appeared such of problem Hou command roast Board member with 75 ℃ * 20 minutes roast photographic white oil Board, exposure feet do 8 level residues, results is developer out whole Board a white fog, is what reasons, competent is touch not with mind, to company brings is big of loss.
Above is a very simple, mainly due to sensitive black and white oil baking sheet time, exposure energy is too low, resulting in bottom did not fully meet the sensitive black and white oil heat, light effect ofdual-cured, it developed a layer off the surface of the black and white oil powder, after it has beenmachine dried on the surface, dust-free paper can be rubbed off.
To solve this problem we simply grilled long time, usually in the baking photographic black and white oilcondition is 75 ℃ + 5 * 40-50 minutes, depending on the thickness. Exposed by 21 12 11 residue clean.
If you are experiencing similar problems, please see the above process, I believe it will achieve thedesired effect.
B, solder printing oil is often found in the Jack a developer dirty oil
Similar problems and I've met several PCB factory causing scrapped, mainly due to a hole developed in theoil rush is not clean, then recoil, or is washed clean, finally took and caustic soda to wash, the result isan oil hole still won't come out, in the end how to also handle hole oil residue, resulting from scrap.
This caused problems such as getting the right treatment is not scrapped, causing scrapped mainly because atthe time of printing screen printing control doesn't work the oil into the holes were too serious, obturatoris dead, and roast as normal on the hole when oil is too thick, unable to complete the hole oil return tothe developer also show off? We can do a test, use a knife to slice the oil out of the hole, holes in theoil is diluted, is diluted oil once again, if the treatment, causing oil resin with a hole on the wall not be cleaned off.
Back again with caustic soda to wash why not wash off? In ink itself no pre roast dry of situation Xia, by Na2CO3 rushed dip, in by caustic soda of soaking, makes of wet of ink was two species chemical potion of attack bite died, will ink of color immersion hole wall of base material within, on like we life in the common of ink make in clothes Shang, dip has yarn, cannot wash off as of truth, results to last how see hole within are has a layer green of oil, caused scrap.
Said has so more of problem, solution this problem I also do has many times of experiment, has once in a company of QC Department found QC Member check to has 100PNL Board hole within has oil rushed not off, will this 100PNL Board took to with 75 ℃ returned 10 minutes, then in developer, results is 100% of all developer clean, again take 20PNL hole within has oil of Board not returned, directly developer, results 70% of still has developer not net, above proved hole within of oil if didn't completely pre roast dry, returned developer is errors of. High speed download
Must control the printer try printing into the holes were too serious, if developed holes in the oil, canreturn to baking take again the treatment we cannot continuously developing, or direct use of caustic sodato foam, so as to avoid waste.