May 06, 2011
The first presentation, "Lead-Free Misprint Board Cleaning Studies," is part of the SMTA China East Vendor Conference and is scheduled from 11-11:25 on May 11 in Booth 1C16, 1/F., West Exhibition Hall of Shanghai Guangda Exhibition Center.
The rapid implementation of lead-free alloys and miniaturization challenges assembly houses to improve yields and reduce costly defects. There are numerous challenges when converting production lines to lead-free. Three areas of concern are co-planar board finishes, no-clean reflowed flux residues and miniaturization. Thin layer PCB finishes readily corrode. Preserving the coatings that protect co-planar board finishes from oxidizing is critical to downstream yields, including rework. Flux changes impact cleaning due to greater residue, high molecular weight compounds, increased oxygen barrier and halide-free. Higher packaging density exposes hardware to corrosive attacks as small components approach the size of corrosive metal migration. Zhang will present misprint cleaning process considerations learned from multiple designed experiments for preserving organic coatings over planar board finishes, removing process residues and integrating with cleaning equipment.
Zhang's second presentation will take place later that day from 14:15-14:45 and is part of the SMTA China East Technology Conference. "Correlation Study for Cleaning Flux Residues under Component Gaps" can be heard in Guang Yun Room No.10, 1/F. at the Shanghai Everbright Convention & Exhibition International Hotel.
Cleaning flux residues from under component gaps has become extremely challenging due to the nature of the flux residue, under component clearance from the board to the bottom of the component, time required for the cleaning agent to penetrate the gap, the cleaning agents ability to solvate and break the flux dam needed to create a flow channel, and the mechanical energy needed to deliver the cleaning agent to the flux residue. Flux residues that form a hard shell require longer wash times to dissolve in the cleaning agent, thus requiring increased time to clean these residues under the component gaps. This presentation will discuss the correlation of cleaning all flux residues under the component as a function of the gap height.
Kyzen is a leading supplier of precision cleaning chemistries to the worldwide electronics, metal finishing, medical, semiconductor, and optical industries. Founded in 1990, Kyzen offers superior cleaning chemistries, technical support, application and analytical services throughout the world. Kyzen has won numerous industry awards for their exceptional products and all products are RoHS compliant.
