An Expired Solder Paste vs Fresh Solder Paste: Reliability and Sustainability in Electronics Manufacturing

Two types of solder paste, where for each there were three production / expiry dates, were compared on a gas chromatography and evaluated in terms of their application using stencil printing on a copper substrate (OSP surface finish). The number, percentage, and number of macrovoids were evaluated and compared. Altogether, six solder paste samples were tested, for each solder paste, the voids were evaluated using X-ray spectroscopy on 14 pads with a 1206 pad size. Despite the results from the gas chromatography showed the effect of solder paste aging, the voiding of the pastes did not differ significantly and, on the contrary, the percentage representation of voids was the smallest with the oldest solder paste.