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Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.

Solder Defects

Leo Gapasin


Solder Defects | 24 October, 2001

We have been monitoring our solder defects at post-SMT, post-Wave, our plant. I want to compare our process performance to a "bench mark" for solder defects at post-SMT. The question I have is what is the "bench mark" for soldering defects in DPM or PPM after SMT process (before Wave). I would like to equate "bench mark" as the "best of breed" for a SMD process.

I will appreciate any input to my question. Thanks to all.

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Michael Parker


Solder Defects | 24 October, 2001

Ceeris is a company that may help you. They collect data and publish benchmark results. Their DPMO report will give you the data you need, for each process step. It's not cheap- they want $3000 per copy.

Beyond that, IPC has created some standards - IPC 7912 is for calculating DPMO. They don't give benchmark results but prescribe a standardized method to get your own results. I have been using this standard for the last 6 months. This standard gives a total process PPM, it not by individual processes. They are working on releasing the next standard that will be department specific. With a little more effort you can create your own target values and ranges per assembly. Use Six Sigma statistics. If you need help, I have developed a series of Excel spreadsheets that you can emulate to collect, calculate and present data in charts and graphs. Contact me direct and I will gladly share what I have.

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Solder Defects | 24 October, 2001

We attended several presentations on AOI machines at a recent SMTA meeting. The presenters gave a section about process verification. They bantied about numbers. [I want to say 350 DPMO, but we glaze over when it gets to that stuff] So, you might be better off talking to them. * Brad Jolly / Agilent * Kevin Dunoon / Omron

I don�t understand the �best of class� bench marking thing. Hasn�t the six sigma process pretty much replaced the bench marking process, because difficulties in controlling, comparing, and evaluating other peoples� numbers? Isn�t 3.4 DPMO pretty much the target? Aren�t you supposed to evaluate the cost / benefit of reaching the next increment of improvement?

Whereas, bench marking seems to allow a cop-out by saying �aw, that�s good enough, Jimmy�s doing it that way�. It�s like your kids whining at dinner [�Jennifer�s mom lets her � You never let me do anything!!! You are so ��] when you won�t let them get branded, er whatever.

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Solder Defects | 28 October, 2001

Hi Mr Parker,

I sent u an email cuppa days back, accepting your kind offer to help "wandering-souls" like us, by your sharing Excel spreadsheet formats, depicting DPMO/PPM graphical calculations, with us.

I was patiently awaiting your reply to my email, until tis morning I noted the thread posting by Mr. Dave F, as follows :

"Don't forget that e-mail links in e-mails received via the SMTnet e-mail system don't work either" *Dave F*

As it is possible you have not received my email request to you, to accept your earnest support in helping the less knowledgable folks, I trust I may receive your Excel spreadsheets, once you find time to read this posting of mine.

My contect is :

Thank you for the help, Mr.Parker.

Regards, ianchan

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Michael Parker


Solder Defects | 29 October, 2001

Ian- I've been out of the office for a few days. Thanks for your direct e-mail address. I will contact you directly with the spreadsheets attached.

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