Cleaning Subtopics

Mike Bixenman, Kyzen Corporation and Michael Konrad, Aqueous Technologies Corporation make an argument for removing flux residue under the quad flat pack no lead (QFN) post-rework, and present cleaning process options for meeting this cleaning challenge. The need for cleanliness under individual components increases as the spacing between connector leads decreases and power increases. The low stand-off height of QFNs traps flux between the ground pad and component leads. Flux trapped under the QFN is a reliability concern. The purpose of this research is to develop process knowledge for cleaning all flux residues from under the QFN device. The authors, representing cleaning material and equipment organizations, investigated process variables such as solder paste, cleaning agents, cleaning equipment, and wash process factors.

Many companies are shifting away from cleaning with pure de-ionized (DI) water to chemistry-assisted processes. Numerous reasons can be cited supporting the recent trend toward cleaning with chemistry. Results from this experiment, presented by Harald Wack, Ph.D., Zestron, support the hypothesis that cleaning temperature and cleaning chemistry concentration can be manipulated to meet cost and cleanliness requirements for the majority of solder pastes.

productronica 2009 will take place November 10–13 in Munich, Germany. Following are more new and flagship products to see at the electronics manufacturing tradeshow, not featured in our Productronica Show Preview: Materials, Productronica Show Preview: Equipment, or productronica 2009: Product Showcase.

productronica 2009 will take place November 10–13 in Munich. The productronica 2009 Website now offers articles, webcasts, and podcasts with commentary and helpful opinions from world experts in a number of disciplines.

IPC announced the September findings from its monthly North American PCB Statistical Program. “We’re finally starting to see the turnaround in the September numbers for the North American PCB industry,” said IPC president Denny McGuirk. “Both rigid PCB and flexible circuit sales and orders are up by double digits compared to August. Rigid PCB sales and orders are still below September of last year, but the rate of decline is shrinking. Flexible circuit business is ahead of September last year. The most promising indicator is the book-to-bill ratio at 1.08,” he added. “It has been above parity for five consecutive months.”

Slumping mobile phone sales, excess network capacity and the protracted death of traditional telecom technology have greatly undercut the demand for communication equipment this year, according to the Henderson Ventures Forecast Summary. Heated price competition in both the handset and network equipment sectors has amplified the downturn. Much of the price pressure has come from two upstart Chinese equipment manufacturers: Huawei and ZTE, which collected substantial market share during the last few years.

Zurvahn is affiliated with Celestica and has formed a strategic alliance that allows Celestica to use Zurvahn’s Business Centers.