Thanks to Ron Hayashi for his reply regarding shelf life of immersion gold PCBs. The boards I have experienced problems with are coming up to 18 months old (I tend to agree with Ron that 6 months is about the maximum shelf life) but I have also looked at the thickness and quality of plating. The gold on the board is 0,014 microns thick using XRF equipment (is this OK?) I thought that seemed quite thin!? I have witnessed 'pitting' in the nickel layer which, in some cases, goes right down to the copper. Can anyone tell me how much nickel / gold should be on the board and what effect the above would have on solderability / shelf life Thanks, Neil Atkinson