HAT tool for fluxless OLB and TAB

Methods and tool sets have been developed to allow fluxless OLB of high lead count TAB (tape automated bonding) components. The hot air thermode (HAT) is such a fluxless process. It can be used for most SMT components and is also well suited for TAB applications. HAT is a pick, place, and reflow system that uses high-velocity heated gas as the medium for solder melting and a dead reckoning method for package placement. Because of the particular tool/process integration employed by the HAT system, the technique does not require ovens with tightly controlled atmosphere and produces solder joints with excellent properties. Elimination of flux also eliminates flux application and cleaning steps during bonding, along with the solvents associated with the flux cleaning. Other advantages of this process include minimized emission during bonding and reduced bond corrosion, since corrosion due to entrapped flux residue is eliminated. The reliability of the solder joints produced by this method are discussed, along with process window data that demonstrate the use of the technique.<>