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SMT electronics assembly manufacturing forum.


Wave Soldering DPPM

Vinesh gandhi

#11056

Wave Soldering DPPM | 14 June, 1999

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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C.K.

#11057

Re: Wave Soldering DPPM | 14 June, 1999

| 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 | | It depends how you define what your "parts per million" is. Some consider parts-per-million to be just individual boards - regardless of the number of parts and solder connections. Others prefer to use "parts per million opportunities." For wave soldering, what's typically used is the number of wave-soldered connections - both TH and SMT. I've heard mixed things as to what's considered "good." ...but if i were to guess 200 DPMO is considered world-class.

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#11058

Re: Wave Soldering DPPM | 14 June, 1999

| | 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 | | | | | It depends how you define what your "parts per million" is. Some consider parts-per-million to be just individual boards - regardless of the number of parts and solder connections. Others prefer to use "parts per million opportunities." For wave soldering, what's typically used is the number of wave-soldered connections - both TH and SMT. I've heard mixed things as to what's considered "good." ...but if i were to guess 200 DPMO is considered world-class. | | | Depends on the boards you are building. Generally, anything under 500 DPM at a wave is good. IF you have ugly boards, you must adjust that upward; if you have easy boards, adjust it downward.

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Brian Ellis

#11059

Re: Wave Soldering DPPM | 15 June, 1999

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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Brian Wycoff

#11060

Re: Wave Soldering DPPM | 17 June, 1999

| | | 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 | | | | | | | | It depends how you define what your "parts per million" is. Some consider parts-per-million to be just individual boards - regardless of the number of parts and solder connections. Others prefer to use "parts per million opportunities." For wave soldering, what's typically used is the number of wave-soldered connections - both TH and SMT. I've heard mixed things as to what's considered "good." ...but if i were to guess 200 DPMO is considered world-class. | | | | | | | Depends on the boards you are building. Generally, anything under 500 DPM at a wave is good. IF you have ugly boards, you must adjust that upward; if you have easy boards, adjust it downward. | We got down to the 50ppm level, using the PPM Opportunities. You must control the quality of your boards, components, etc. Another factor that ust be considered is the design of the board. We never got there on some products becuase of the board design. For example; SOT23 components at wave solder are a problem throughout the industry when the standard pad designs are used. Many of those issues can be overcome if the pad geometry is modified. It is possible, but takes significant time, cost, and effort to get there.

Brian

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