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Gold thickness

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aj

#55445

Gold thickness | 10 July, 2008

Hi all,

What should the typical gold thickness be on ENIG boards ?

aj...

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#55461

Gold thickness | 10 July, 2008

Search the fine SMTnet Archives to find threads like: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=33661

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aj

#55468

Gold thickness | 11 July, 2008

Thanks Dave,

IPC-6012 states min at 0.05um.

Has this been a update or is it for a different class?

thanks,

aj...

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#55470

Gold thickness | 11 July, 2008

0.05 um => 2 uinch, right?

Here is the revision level for IPC documents: http://www.ipc.org/4.0_knowledge/4.1_Standards/revstat1.htm

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aj

#55471

Gold thickness | 11 July, 2008

Hi Dave,

Yes that is correct.

I had a XRF carried out on some boards that I am having solderability issues on and the report came back with 0.04um - 0.05um as the measured gold thickness.

Previous batches that went through fine measured 0.07-0.11um.

aj...

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#55533

Gold thickness | 15 July, 2008

Hi Aj,

Recommended Immersion gold thickness would be 3-5 Micro inches over 140 -200 micro inches of Nickel.

Thicker Immersion gold than 5 micro inches can cause solder joint embrittlement. Gold readily dissolves in molten solder and will be present in the reflowed solder joint. Intermetallic gold-tin compounds formed cause joints to be brittle, and the gold film must therefore be thiner to minimize the amount of intermetallics.

Enig is just their to protect the soldering surface which is the Nickel.

Regards, Boardhouse

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#55712

Gold thickness | 28 July, 2008

Please look up http://www.shanelo.co.za/Black%20Pad%20Index.htm and check out the article named"Soldering to gold a practical guide."

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