The other answers on this thread are realistic but it also depends: a) on the quality and finish of the components and PCB (including, of course, solderability) b) the flux type (I would expect lower defect rates with water-soluble than with the less corrosive "no-clean" types) c) the type of wave soldering machine (e.g. a double-wave may give more defects with some fluxes and less with others) d) above all, the preheat characteristics: as you are into motherboards which are usually multilayer, you need powerful preheating to activate the flux to allow the solder to rise up PTH component holes (aim for 95-100�C on the top pads) e) the precision of the gluespot application f) etc. etc. etc.
These factors could swing the defect rate up or down over two orders of magnitude. IMHO, 50 ppm is utopian in most cases and is typical of what "big bosses" say when they don't have a clue but are pressured by the shareholders to cut costs.
Good luck in your persuading them!
Brian
| Dear All, | | We are having a big debate over what is the industry standard in DPPM on the wave sodlering process. is a DPPM of about 800 satisfactory. As per our big bosses it should not be more than 50 DPPM. Is the figure realistic. We are typically into the motherboard business, where the board comprises of big connectors/small capacitors and fine pitch PPGA connectors. | Please inform about what are the average DPPMs in your process. | | Best Regards, | Vinesh Gandhi | |
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