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ENIG

Views: 3878

#57821

ENIG | 20 January, 2009

Hi

We have just specified the following thicknesses for the Nickel and Gold on an ENIG finish board. The baord is to be manufactured using a lead - free process. My question: Is the thickness we've specificed likely to gie us any issues during manufacturing or with brittle solderjoints? The Thicknesses are as follows: Nickel Thickness is 3uM-7uM Gold Thickness is 0.05uM-0.1uM

Thanks in advance

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#57826

ENIG | 20 January, 2009

While you're waiting for others to reply, search the fine SMTnet Archives to find threads like http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=57106

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#57836

ENIG | 21 January, 2009

Hi Adam, I would suggest you refer IPC-2221 guidelines which define plating thickness as: Nickel 2.5-5.0 um , Gold 0.08-0.23 um. Although ENIG is a standard process, there is an associated risk towards Gold embrittlement, Porous Gold, or Black pad defects, caused due to inadequate plating thickness. You could refer your board to a test lab for solder joint analyses to confirm your ENIG plating quality.

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#57851

ENIG | 22 January, 2009

I think IPC-4552 is define the thickness of Nickel as: 3 to 6�m and Gold as: 0,05�m minimum

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#57867

ENIG | 22 January, 2009

If you wish to specify ENIG, your best method of doing it is to simply invoke IPC-4552 (or IPC-4553 for immersion silver) on the fabrication drawing. These IPC standards define ENIG and IAg, and I believe they specify 150-180 uinches of nickel covered with 3-6 uinches of gold for ENIG. You can certainly specify anything else if you wish, but they will not be ENIG or IAg as recognized by the industry, and you open yourself up to problems if the plating is not done per the standards and issues such as brittle nickel, black pad, etc., develop. The fabricator is no longer on the hook for the quality or performance of the finish.

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