IPC-A-610 Section 4.4 (Soldering - Gold Fingers) refers to a Critical Contact Area of 6.4mm which is determined by 4.1mm contact clearance and 2.3mm for variation and possible play.

The Gold Finger length on all our boards is 6.4mm

Q. Does this mean that our entire (6.4mm) gold finger is deemed to be in the critical contact area?

Q. If so, does this mean that we cannot allow any solder on any part of our gold fingers.

IPC-A-610 Figure 4.39 shows a typical gold finger with the (6.4mm) critical contact are shown between two dotted lines, this would make  the gold finger appears to be ~ 10mm long. 

Q. Is this 10mm gold finger length correct?

Q. Is this 10mm gold finger length typical?

Regards,

Tom Collins
Stratus Computer Ireland
Supply Base Engineer

email: tom_collins@stratus.com
phone +353 1 809-6333