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should gold pads be pretinned, what issues are known are there?

kevin

#21615

should gold pads be pretinned, what issues are known are there? | 18 September, 2002

as the title says, should gold pads be pre-tinned, and are there any issues with soldering to gold pads?

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#21617

should gold pads be pretinned, what issues are known are there? | 18 September, 2002

Effects of Gold (Au) on Solder Properties Concentration Range in Weight Percentage w/o Au in Sn63/Pb37 Solder [A Sugarman/Loranger] * 2.0 - 3.0% Spreadability and fluidity of solder reduced (1) * 3.0% Highest acceptable concentration of Au in solder before deleterious effect can occur. (1)

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#21622

should gold pads be pretinned, what issues are known are there? | 18 September, 2002

Dave,

anything besides gold embrittlement to be concerned about if that concentration is exceeded? Never tried the stuff.

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#21624

should gold pads be pretinned, what issues are known are there? | 18 September, 2002

IMHO, this finish is more cosmetically appealing than technically desirable (and VERY profitable for the PCB maker).

That editorial comment aside, you're correct. Increasing the concentration of gold: * Hardens the solder. * Increases the liquidous temperature.

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