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
Electronics Forum | Tue Sep 04 13:41:52 EDT 2001 | Brian W.
IPC7912 deals with the end result, ie an OEM getting boards from a contract manufacturer. I have a friend who is sitting on these committees. He tells me there is a new standard due out for actually doing in-process DPMO. From a process standpoint
Electronics Forum | Wed Sep 05 08:22:48 EDT 2001 | davef
Jack Crawford, IPC Director of Assembly Standards and Technology says "IPC-7912 is used for end-item DPMO calculation; one gathering of DPMO data at the end of the entire assembly process. IPC-9261 will be used throughout the manufacturing process so
Electronics Forum | Wed Apr 09 15:05:45 EDT 2003 | russ
Probably of no help but here it is anyway This is a tuff one. Attrition is due to many factors. You have machine rejects (visual fail, no pick), feeder set-up loss each time a reel is removed you lose X number of parts depending on feeder design (w
Electronics Forum | Fri Sep 28 16:49:48 EDT 2007 | davef
good * No IMC => bad Intermetallic growths are diffusion limited, and therefore the thickness of the intermetallic is given by: z^2 = (Do)(t)exp[-Q/RT] Where Do (m^2 s-1) is the diffusion coefficient, T(�K) is the temperature, Q (J mol-1) is the act
Electronics Forum | Mon Feb 06 17:19:59 EST 2017 | davef
Evtimov: IDEALS Project was one of the first to talk about componebt and board damage caused by LF soldering temperatures. There's lots of more current stuff on the web. Here's some that may help: * Assessment of Long-term Reliability in Lead-free As
Electronics Forum | Wed Oct 10 20:58:30 EDT 2001 | davef
Several points are: * There�s quite a bit of background on IMC in the fine SMTnet Archives. I�ll try not to duplicate it. * If you have a smooth and well-formed solder connection using fairly common materials, you assuredly will have IMC. Any evide
Electronics Forum | Mon Aug 14 18:24:36 EDT 2000 | Dave F
James: Here's a starting point: 1 www.wwnet.net/~rkroy/wp-inb.html 2 www.sas.com/otherprods/jmp/Home.html 3 www.micromeg.com/ 4 Boeing SQC (avail. from Boeing for $100) is a good little package for DOS machines. 5 For Windows, SPC KISS from Air Aca
Electronics Forum | Thu Jun 22 11:01:54 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
Electronics Forum | Thu Jun 22 11:02:13 EDT 2000 | Chrys Shea
Jason, Double sided reflow should be no problem. People have been doing it for years. The surface tension of the molten solder will hold the components on the bottom side during your second pass. This is almost always the case, unless you have re
