Electronics Forum | Fri Mar 30 06:58:24 EDT 2007 | ck_the_flip
Alot of QM's and QE's are typically failed Engineers who lack common sense. They don't understand that measuring in DPMO's (versus DPU's) "normalizes" your data for Printed Circuit Board Assemblies (PCBA's) so that if you have 10 defects on a PCBA t
Electronics Forum | Wed Nov 18 10:39:48 EST 1998 | Scott Lolmaugh
| | | Does sombbody know what DPM rate a good and reliable SMT assembly line (incl. solder paste print, assembly and feflow soldering) has? | | | | | Chris, | | It may be helpful if you could translate DPM into a meaningful phrase as many people (my
Electronics Forum | Thu Nov 30 13:51:33 EST 2000 | Michael Parker
Thanks for the details. Next question- where is your first time pass rate measured? Is this at test? Do you have inspection gates at the end of each process step? To get to the root cause, you need the earliest detection. Collect attribute data by a
Electronics Forum | Tue Jun 14 10:38:53 EDT 2005 | Stefan
500 rejected (?) per million placed components is a very good rate, considered that it would be better than 4 Sigma if you name it defects on the board. Or do I incorrectly convert ppm to dpm? * 3 Sigma 66,800 defects per one million opportuniti
Electronics Forum | Fri Jun 07 14:05:39 EDT 2024 | davidk
I wanted to open a discussion and ask about opinion: What is a normal result of the inspection of an AOI? How many falls calls per component /opportunity is bad/normal/good? How many defects per component/opportunity is bad/normal/good? What is goo
Electronics Forum | Wed May 09 01:40:55 EDT 2001 | Dreamy
Hi Michael, DPMO Index calculation - The total number of defects (Dc + Dp + Dt) on a completed Printed Circuit Board divided by the total number of defect opportunities (Oc + Op + Ot) for that PBA multiplied by 1 million. Your calculation deals only
Electronics Forum | Fri May 23 15:31:46 EDT 2003 | daanterstegge
Hi ChrisX, DPMO = number of defects per million opportunities. PPM (parts per million) is exactly the same, although the terminology is less clear about what it means. SPC(statistical process control) is a methodology based on statistical technique
Electronics Forum | Thu Jan 04 17:04:43 EST 2007 | slthomas
99% good solder joints = 10000 ppm (defects per million opportunities). Having only built with 0603s I can't speak for a target but that still seems pretty harsh....with a 75/25 0805/0603 ratio at my last place of employment I think we were running
Electronics Forum | Sat Jun 12 10:23:18 EDT 1999 | Dean
| How are you inspecting pcbs post-reflow, are you inspecting all or sampling. The type of assembly involved would be mainly chip components with a mix of actives and a few 25mil and under pitch. | If you sample what are your fault rates looking lik
Electronics Forum | Tue Aug 28 12:05:42 EDT 2001 | mparker
The advantage of DPMO is that the numbers used are PPM, (Part Per Million), rather than percentage. Percentage can distort, depending on volume. For instance, 100 units processed, 25 defects found = 75 percent yield. 4 units processed, 1 defect found
