I have checked with my friends that run the Engineering of board fabrication in Taiwan and China about continuing ENIG "Black Pad" problems. They say that the problem is still "with us" but it seems to have a cause "that has yet to be discovered". Some say that their research and customer returns show that it can appear "randomly" on the Secondary Side with finer-pitch BGAs. It is confined to <1-3%. The bad pads are adjacent to perfectly good pads. Process chemistry has been adjusted to eliminate the problem, but it still persists. The universal solution is moving to immersion silver as fast as possible. Some Asian shop will no longer take orders for ENIG if there is BGAs on the Secondary side. Other are dropping ALL ENIG orders if the customer cannot switch to Immersion Silver. Others require a SIGNED - BUY AT YOUR OWN RISK paper. The problem does not seem to have a solution and may be caused by a principal as of yet not discovered, but related to fine-pitch and assembly.
Happy Holden
-----Ursprungligt meddelande-----
Från: Eddie Rocha [mailto:[log in to unmask]]
Skickat: den 6 oktober 2003 23:51
Till: [log in to unmask]
Ämne: [TN] ENIG solder joint embrittlement
Does anybody have data or literature which shows that solder joint
embrittlement is not an issue when ENIG is used? I have a customer
that needs this supporting data before he can allow us to use ENIG. Is
this embrittlement issue related only to a certain thickness of gold?
I'd appreciate any feedback on this topic.
thanks,
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