Solderability of fired-silver/platinum/palladium lead terminations

Does anyone have any experience with fired-silver/platinum/palladium lead terminations soldering. I have had issues on nickel over gold plated boards but not with HASL'd boards with tin/lead pads. Is this the norm?

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Yes, norm it is. Look back to February 98 discussion on this issue.

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| Yes, norm it is. Look back to February 98 :discussion on this issue. Norm, That discussion does deal with palladium coated leads, but when I read your statement about silver/palladium fired terminations, I'm assuming that you're referring to passive component terminations...there's different issues with that. I've seen some capacitors, and a component called a "Thermistor" that have had silver palladium terminations. You still will have the issue of seeing a strong demarcation line between the solder fillet and the lead or termination itself, but another issue that comes up with these passive components that doesn't happen with leaded devices, is that when you try and touch-up a solder joint on a passive component, it is VERY easy to remove or destroy the termination during the touch-up...the termination will leech right off of the component. This can be prevented by using a 2% silver solder and making sure that the soldering iron temperature is as low as it can be and still get the job done, and that the touch-up is accomplished very quickly. You don't want to keep the joint liquidous for very long at all. -Steve Gregory-

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