In response to Jim Trainors comment on solderability of OMIKRON White Tin after ageing, 1. In a test performed by Trace labs comparing solder paste wettability among three surface finishes: HAL, OMIKRON and Alpha Level, it looked at the surface area as measured by a planimeter and OMIKRON wet the no clean solder paste the best! Sure--the wettability is less after aging--whether dry or steam, but the degree to which it falls is less than HAL or Silver! 2. Wetting balance tests (reference to the meniscus) is just one way of measuring wettability. I think this test does not very accurately depict real conditions. When one reflows solder paste, you are looking not at the instantaneous force, but a reflow time of 30 seconds or so (the time the reflow temperature is above the liquidus)--take a look at your typical solder paste reflow profile. This is why we typically look at how well the solder paste spreads over the surface and this is the type of test Lucent Technology does as well. 3. Sure--the reason for the degradation in wettability is due to growth of intermetallics--however the key is surface tin. As long as there is surface tin, the surface will wet. Our test results show that surface tin remains after aging combined with multiple reflow cycles. 4. Finally, I would be more than happy to supply you with all of our test data, in house as well as Trace Labs (an independent lab). It will address this issue and others that may interest you. There are more than 30 shops throughout the U.S. currently running Omikron as an alternative to HAL, all their boards are not being assembled inside of one week. The shelf life is safely rated at one year min with the correct deposit. Kind Regards, Stephen M. Wentz Florida CirTech VM#(408)233-0443 ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################