CLOSING THE CLEANING GAP

摘要

With the advent of no-clean fluxes and solder pastes, the need for cleaning electronics assemblies disappeared.rnOr so some would have you think.rnBut while the masses switched, ahem, en masse, to no-cleans, often in hopes of eliminating what was widely seen as a non-value-added step from the assembly process, a not-so-funny thing happened: Field failures and legislation.rnThe influx of no-clean coupled with better process control drove the use of cleaning to general consensus of 5% of all boards, mostly for high-reliability applications such as military, certain telecommunications, and aerospace. But the broad switch to Pb-free solders, prompted in large part by the RoHS Directive, and more densely packed boards that effectively turn even trace residues from aesthetic nuisances into potential hazards, has brought about a renaissance for cleaning advocates. And to a degree, suppliers of cleaning materials are, well, cleaning up.