Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


White tin pcb, smt production

David Bratcher

#32953

White tin pcb, smt production | 1 March, 2005

What thickness is required to process a double sided board with white tin? Is there an IPC standard? If rework is necessary, what is required?

This message was posted Add this forum to your site! Click to learn more. the Electronics Forum @

reply »

#32963

White tin pcb, smt production | 1 March, 2005

IPC Plating Committee is presently working on a specification for immersion tin [IPC-4554 Specification for Immersion Tin Plating for Printed Circuit Boards] as a solderable surface finish. Immersion tin is normally deposited at 30 to 60 microinches. Look here: http://www.ipc.org/status.asp

Some people prefer immersion silver over immersion tin, because of the higher temperatures requried by immersion tin.

reply »

#33054

White tin pcb, smt production | 5 March, 2005

You can also try the Florida Circtech website or call them direct. There is a min. thickness requirement and if the board house does not follow it you will end up with scrap boards after the second pass (from experience). I even sent blank boards to Florida Cirtech and they were able to measure the thickness (results were it was under spec)...we've since scratched the pcb supplier from our vendor list. I agree with dave, immersion silver might be a better way to go given the immersion tin limitations on number of heat cycles directly related to finish thickness.

Gus

reply »

Non-heated dispensing system

Real-time PCB X-ray Inspection System