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From [log in to unmask] Sat Apr 27 15: |
01:16 1996 |
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We are having some problems soldering to an electroless gold over
nickel card. specifics are:
5-10 microinches electroless gold over 20 microinches electroless
nickel. .020 thick double sided smt card being soldered in a nitrogen
covection reflow oven. components range from 0603-1206 passives, sot
23 devices, and a 25 mil ssop.
Soldering is being done using Alpha 609 water soluble 63/37 paste with
a fairly standard profile.
Results thus far are that the joints are granular, cold appearing,
with marginal wetting to both card and components. There are also
numerous occurrances of voids/pinholes eminating from the lead pad
interface.
Any insights would be helpful in the areas of:
Profiles
Pastes
Methods for checking incoming solderability of the cards.
Any thoughts on optimal gold/nickel characteristics
Thanks for the help.
Steve Ethier
Mgr. New Product Engineering
Lockheed Martin Commercial Electronics
Tel: 603-885-8432
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