Hi Graham - the 100 uinch value is applicable to PTH technology solder joints, the limit for SMT technology solder joints is much lower. The issue is gold embrittlement which isn't just driven by the gold thickness, you also need to take into account the volume of solder for the joint and the time/temperature parameters - aka do you give the gold sufficient time to diffuse throughout the solder volume. The IPC JSTD-001 Handbook and the IPC-820 Handbook both have some good information on gold thickness/gold embrittlement topic. Good Luck. Dave Hillman Rockwell Collins [log in to unmask] Graham Collins <[log in to unmask]> Sent by: TechNet <[log in to unmask]> 08/15/2012 02:15 PM Please respond to TechNet E-Mail Forum <[log in to unmask]>; Please respond to <[log in to unmask]> To <[log in to unmask]> cc Subject [TN] gold removal question - to remove or not? Hello Technet I'm in the midst of a debate about gold removal. Our policy on component leads is to double dip tin all gold. J-STD-001 says I do not have to do it if there is less than "2.54 ìm [100 ìin]" of gold, but is it realistic to operate on that basis? For example, looking at an Airborne brand connector I find the spec sheet says that there will be 50 ìin gold, minimum. Which is not totally helpful as it does not tell me maximum. I'm assuming given the price of gold that they aren't looking to put a lot more than the minimum on, but how controllable is the process? Could we check the thickness once and assume we are safe? (and as you can tell from my phrasing I'm of the more conservative camp on this one, still dipping the parts until proven wrong) regards, Graham Collins Halifax Production Engineering (902) 873-2000 ext. 6215 This message and any attachments are solely for the use of the individual or entity to which it is addressed and may contain information that is privileged or confidential or controlled technical data that is subject to the laws of Canada or the United States. If you are not the intended recipient, any disclosure, use or distribution of the information contained herein is prohibited. If you have received this communication in error, please notify the sender by reply e-mail and immediately delete this message and any attachments. ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________ ______________________________________________________________________ This email has been scanned by the Symantec Email Security.cloud service. For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________