Talk:Gold plating

Untitled
This is way too wordy. I really don't care about formulas or curcuit boards. I'm not a scientist. I don't like scientists. 72.204.141.105 (talk) 15:28, 23 June 2008 (UTC)
 * Personal feelings are banned in Wikipedia. — Preceding unsigned comment added by 79.77.163.188 (talk) 14:37, 10 May 2021 (UTC)
 * They always have been.

ENIG for PC Boards
Electroless Nickel Gold is what's typically used for surfacing bare PCB's - it's used to keep the pads from oxidizing. In fact, the gold dissolves into the solder. This is where the ENIG plating thickness is critical - anything over 50-100 microinches can lead to embrittlement - non-metallic formations that compromise the solder connection. The IPC section in J-STD-001: 4.5.1 Gold Removal

Gold shall be removed:

From at least 95% of the surfaces to be soldered of the through-hole component leads with 2.54 μm [100 μin] or more of gold thickness. From 95% of all surfaces to be soldered of surface mount components regardless of gold thickness. From the surfaces to be soldered of solder terminals plated with 2.54 μm [100 μin] or more of gold thickness.

A double tinning process or dynamic solder wave may be used for gold removal prior to mounting the component on the assembly.

J STD-001 Revision “F” (For all classes) now states:

(the changes are underlined)

4.5.1 Gold Removal

Gold removal is performed to reduce the risk of failure associated with embrittled solder. Gold embrittlement is not a visually inspectable anomaly. In cases where analysis has determined there is a gold embrittlement condition, the gold embrittlement shall be considered a defect, see IPC-HDBK-001 or IPC-AJ-820 handbook for guidance. Except as noted above, gold shall be removed:

From at least 95% of the surfaces to be soldered of the through-hole component leads with >2.54 μm [100 μin] gold thickness and all through-hole leads that will be hand soldered regardless of gold thickness. From 95% of all surfaces to be soldered of surface mount components regardless of gold thickness. From the surfaces to be soldered of solder terminals plated with >2.54 μm [100 μin] gold thickness and from all solder cup terminals, regardless of gold thickness.

A double tinning process or dynamic solder wave may be used for gold removal prior to mounting the component on the assembly.

Note: Gold embrittled solder connections can occur regardless of gold thickness when solder volume is low or the soldering process dwell time is not sufficient to allow the gold to dissolve throughout the entire solder joint.

A video explaining that you cannot solder to hard gold plate without removal: https://www.youtube.com/watch?v=HG0mKZBLFVo&t