Electronics Forum | Sun Jul 15 20:10:09 EDT 2001 | Danial
What is the best method to repair Warped PCBA. Obviuosly twisting it back to make it flat would be a disasterous. The method that I've tried wold be mounting the assembled board to the flat holder with the clamp and bake them at 120 Deg C for about 4
Electronics Forum | Mon Jun 13 16:15:04 EDT 2005 | peter ng
Dear all, We faced some major issue in setting our company target to 500 points per million at machine throw rate.It might be caused by human error,machine,feeder,environment or other factor.We need some opition and advise on how to achieve this targ
Electronics Forum | Mon Jun 13 16:17:30 EDT 2005 | peter ng
Dear all, We faced some major issue in setting our company target to 500 points per million at machine throw rate.It might be caused by human error,machine,feeder,environment or other factor.We need some opition and advise on how to achieve this targ
Electronics Forum | Tue Jun 14 15:03:15 EDT 2005 | slthomas
In that the machine times out and waits for a feeder refill and doesn't just skip that part and leave the space empty, it's not a defect. I have found 500ppm *fairly* easily attained in SMT depending on the board mix and how you define (1) a defect,
Electronics Forum | Tue Jun 14 16:37:56 EDT 2005 | slthomas
You may be right. I may have read something into his post that wasn't there....
Electronics Forum | Tue Jun 14 16:21:15 EDT 2005 | pr
My chipshooter will not "Time out", it will try to pick 3x and then alert the operator. Which would be 3 misses per empty reel. Unless I misread his post, he said 500 ppm at the placement machine. That makes a big difference.
Electronics Forum | Wed Jun 15 00:50:32 EDT 2005 | Frank
From my understanding: Sigma is the same as one standard deviation. So 3 sigma is the same as 3 standard deviations. It all boils down to how repeatable your machine is. Another way to look at it is the probability (or confidence) that the machin
Electronics Forum | Tue Jun 14 11:25:19 EDT 2005 | pr
Sounds a little tough to achieve. Math isn't my strongsuit but...If you run a million parts through the machine, you will have 200 feeder exhaust's (assuming 5000 per reel). So if you have your machine error out after 3 attempts/misspicks you will ha
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 | Mon Jul 16 21:44:07 EDT 2001 | davef
You�re correct. If you attach $5 to each board, your customer will be happy to approve your process change. Consider: �Process Improvement Strategies: Implementation Of A No-Clean Process" http://www.smta.org/knowledge/proceedings_abstract.cfm?PRO
