WF-7742 is a VOC-free, no-clean flux specifically developed for Pb-free wave soldering of surface mount, mixed-technology, and through-hole electronic assemblies. 7742 is a water-based, nonflammable formulation dramatically reducing VOC emissions and eliminating special storage requirements. A wide process window provides excellent solderability on difficult-to-solder assemblies and reduces solder balling.
- Excellent surface wetting
- Eliminates cleaning
- Wide process window
- Use with Pb-free and SnPb assembly processes
WF-7742 should be applied by ultrasonic spray for best results. Topside board temperatures can range from 110–135°C depending on equipment capability and assembly requirements. Contact with the solder wave can be as long as 5 seconds. Preheat temperature should be adjusted to ensure complete water removal before contact with the solder wave.
A thin uniform flux deposition of 1,000–1,500 micrograms per square inch of flux solids should be applied as a starting point. Because WF-7742 is water-based, it does not require frequent acid value monitoring. If thinning is required, deionized water should be used.
WF-7742 may freeze if exposed to temperatures below 0°C (32°F). If the flux becomes frozen, bring to room temperature until thawed and agitate. The material is not affected by freezing.