At risk of pointing out the obvious....
Hard Gold has exposed Copper on the sides of the traces and pads, wheres ENIG covers any exposed Copper, not covered by soldermask.
Rudy Sedlak
RD Chemical Company

--- On Tue, 8/14/12, Glidden, Kevin <[log in to unmask]> wrote:

From: Glidden, Kevin <[log in to unmask]>
Subject: [TN] PCB finish: ENIG vs. hard gold
To: [log in to unmask]
Date: Tuesday, August 14, 2012, 9:12 AM

Hi everyone,

We have a PCB supplier who is offering "Hard Gold" as an alternate to ENIG finish, due to PCB size and processing capabilities.  The application is Class 3 (mil/aero).  The circuit is thin FR4 and subject to SMT reflow w/ Sn63Pb37 (non RoHS) solder alloy, and moderate flexing in end application.

Can anyone offer info on the differences between the two finishes, and/or their suitability?  Is there an IPC spec (or specs) that outline "hard gold"?

Thanks,

Kevin Glidden


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