In most cases, all that is needed is about a 25um layer of flux on the bonding surfaces and solder – usually 2-4% mass of the solder. Flux should almost never be of equal volume as your solder (except for some solder pastes). The perfect amount of flux will be enough to form a good solder joint, but will clean well (for water or solvent soluble fluxes) or appear clearer with less residue (no-clean fluxes). In extreme cases, lowering flux volume can improve reflow cycle time, because complete activation can occur sooner – and thermal inertia is decreased. More volume is also more expensive. Keep this in mind and dial in your process.
Wafer-Level Microsphere Bumping (Flux)
Indium Corporation Blogging Team
Indium Corporation Blogging Team
Our blogging team includes engineers, researchers, product specialists, and industry leaders. We share expertise in solder materials, electronics assembly, thermal management, and advanced manufacturing. Our blog offers insights, technical knowledge, and solutions to inspire professionals, showcasing product innovations, trends, and best practices to help readers excel in a competitive industry.
