Electronics Forum | Wed Aug 21 01:40:42 EDT 2002 | jkhiew
Hi all, Our management set target 50 ppm for overall process like printing,mounting & reflow soldering. Our m/c cpk for mounter is 1.0 & for printing is 1.33. So, pls comment !
Electronics Forum | Wed Aug 21 03:27:32 EDT 2002 | jkhiew
Hi Ken, Our printing is 49ppm, mounting is 83ppm & reflow is 150ppm. RDGS
Electronics Forum | Wed Sep 04 14:33:26 EDT 2002 | slthomas
We fondly refer to those charts as "wall art".
Electronics Forum | Sat Jan 15 16:59:47 EST 2000 | Steve Thomas
Thanks, Mark. Actually we already have an established mark. We use 500ppm (99.95%) as our acceptable level. Problem is, someone (another manufacturer) told someone else (our pres.) that THEY build to 50ppm. Soooooo, someone else told my boss that
Electronics Forum | Wed Aug 21 02:11:58 EDT 2002 | kenbliss
Hi Joseph It is not clear what you want us to comment on, however I will take a shot. 1. If the boards you are assembling are expensive it may make sense to strive for 50ppm. 2. If the boards are not very expensive, in my experience you would be
Electronics Forum | Mon Jan 22 22:37:27 EST 2001 | davef
50 ppm oxygen was on half joints reflowed in air. 3d Human factors PCB pad cleanliness: Handling of bare board pads creates excessive voiding. Print rejection: Cleaning of OSP pads with acetone or isopropanol increases voiding.
Electronics Forum | Fri Aug 23 20:11:34 EDT 2002 | jersbo
thats the problem with numbers... how accurate are they anyway? Can someone tell me how to collect data and assure me that its not someones biased opinion?
Electronics Forum | Tue Sep 03 14:18:49 EDT 2002 | dragonslayr
Jersbo- I will refer you to the late, Great Mark Twain, who once wrote: "There are 3 kinds of lies in this world - Lies Damn Lies and Statistics"
Electronics Forum | Wed Aug 21 17:50:05 EDT 2002 | davef
First, it�s GREAT that your defect rate of 282 is very close to your Boss� goal of 50 ppm. Second, your Cpk and your ppm numbers don�t tie out with our expectations. You say Cpk for: * mounter is 1.0 and �your mounting is 83ppm�. * printing is 1.33
Electronics Forum | Wed Aug 21 18:11:47 EDT 2002 | dragonslayr
..and the choir is humming in 5 part harmonies. Personnally, I never gave much truck to Cpk stuff. Seems to be a high falutin way of showing the lowerlings that academics can manipulate numbers. Dazzle 'em with brilliance or baffle 'em with bull puke
