When your smartphone drops a call, your car's airbag fails to deploy, or industrial equipment shuts down unexpectedly, you probably don't think "ionic contamination on the PCB." But these invisible residues—the remnants of solder flux, fingerprints...

Every reliable solder joint begins long before the paste is dispensed or the reflow oven reaches temperature. The quality of the bare printed circuit board surface arriving from fabrication—and the preparation it receives before assembly—determines...