Electronics Forum | Thu Aug 29 17:45:54 EDT 2002 | nifhail
What are other testing/process step that we should do if we where to use the old date code QFPs other than solderability and baking ? What is the plating composition normally %? lead, % tin etc. I have my policy not to accept the more than 12 mont
Electronics Forum | Wed Jun 25 12:13:31 EDT 2003 | russ
A lot of it depends upon what the lead terminations are and the storage conditions. For example if they are tin you will run into trouble. We have used all types of parts that are all ages (We just started doing BGAs that are 5 years old.) I don't
Electronics Forum | Wed Jul 29 13:44:45 EDT 1998 | David Spilker
We are investigating alternatives to HASL finishes for more dense PWBs. OSP is not a good choice because of low solid flux and possibly long shelf life. Immersion gold is expensive and so far has been more difficult to wave solder. Has anyone had
Electronics Forum | Wed Aug 09 08:06:07 EDT 2006 | davef
See "IPC-4554 Specification for Immersion Tin Plating for Printed Circuit Boards" 3.2.1 Immersion Tin Thickness. The most common reason for solderability issues with the white tin surface coating during multiple thermal excursions is a thin white ti
Electronics Forum | Wed Aug 05 07:46:46 EDT 1998 | Earl Moon
| We have mixed to negative feelings about Omikron, but I beileve it is due to problems with the board fabricator rather than the process itself. When done properly, our Omikron boards have had very good solderability. However, we have had several
Electronics Forum | Wed Feb 23 00:45:49 EST 2011 | tsvetan
Does someone with technical knowledge knows what exactly happend with the solder paste after the shelf life pass? What we have seen is sometimes flux separation which disapear after a good mix, and change of viscosity i.e. drying. The tin, silver and
Electronics Forum | Wed Jul 29 22:50:17 EDT 1998 | Dave F
| We are investigating alternatives to HASL finishes for more dense PWBs. OSP is not a good choice because of low solid flux and possibly long shelf life. Immersion gold is expensive and so far has been more difficult to wave solder. Has anyone ha
Electronics Forum | Mon Dec 14 10:53:10 EST 1998 | Earl Moon
| Has anyone had any experience with using this alternative plating process? Some board houses are pushing toward this plating. Is there any long term data on this process? Any problems experienced with smt and thru-hole? I've heard tin whiskers to b
Electronics Forum | Fri Nov 07 15:57:56 EST 2003 | Marc Simmel
Are there specifications or recommendations for electro-deposited tin-lead plating thickness on austenitic stainless steel that would provide a shelf life of 1 year? 6 months? Would 2 to 3 microns (78 to 118 micro-inches) 90/10 tin-lead over 1.27 mi
Electronics Forum | Sat Nov 08 10:04:26 EST 2003 | severs
Once you have selected your plating based on electrical and physical requirments, you should know that there is an inexpensive plastic storage packaging developed by Lucent which can keep any platings solderability from degrading for up to 10 years o