Dave,
We don't reference the marking spec, the RoHS legislation doesn't actually require specific marking, just certification of compliance. So marking is up to you, use 609 or make your own. But make sure you don't just ask for a mark, specify that it is actually compliant! There are vendors who will mark a non-compliant part with the logo, if that's all you ask them to do.
I personally don't like the slash sheets anymore, they are too ambiguous, I think they are no longer relevant. I specify whatever material specs are important to me - Tg, Td, Z-axis CTE, FR-4, Dk, etc.
Non-Dicy actually has nothing to do with RoHS. Dicy and Non-Dicy curing agents are equally compliant. However, Dicy materials are prone to CAF failures, Z-Axis expansion problems, breakdown under multiple thermal excursions.... So I specify Non-Dicy to avoid the problems. Speaking of irrelevant, that spec may be soon, as fewer laminate manufacturers seem to be producing materials with the dicy. As more people spec CAF resistanace and better CTE, they have to use non-dicy to meet the specs, soon dicy will be obsolete. And almost none of the laminate makers will offer the dicy information on their datasheets. You will have to ask if they use dicy, or make the assumption from their advertising CAF resistance.
I would suggest getting copy of Werner Engelmaier's whitepaper on FAB notes and specs for lead free soldering.
http://www.engelmaier.com/white-paper.html
Pete
---------------------------------------------------------------------------------
DesignerCouncil Mail List provided as a free service by IPC using LISTSERV 16.0.
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF DesignerCouncil.
To temporarily stop/(restart) delivery of DesignerCouncil send: SET DesignerCouncil NOMAIL/(MAIL)
For additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
---------------------------------------------------------------------------------
|
