1.Product Description
Kester 985Mis a low-solids, halide-free, no-clean flux that is designed for wave solder, selective solder and touch up processes. 985M was developed for use with both traditional tin-lead and lead-free solder alloys. 985M exhibits improved soldering performance to minimize solder bridges (shorts) during all soldering operations. This flux is suitable for automotive, computer, telecommunications and other applications where reliability considerations are critical. As tested under J-STD-004 specifications 985M is classified Type ROL0.

2.Performance Characteristics:

■ Improves soldering performance
■ Eliminates the need and expense of
cleaning
■ Non-corrosive tack-free residues
■ Classified as ROL0 per J-STD-004
■ Compliant to Bellcore GR-78

3.

Process Considerations
The optimum preheat temperature for most circuit assemblies is 85-105°C (185-221°F) as measured on the top or component side of the assembly. It is important to note that the optimum preheat temperature for a given assembly will depend on the combination of machine design, board mass or size and component mix and Alloy used in the solder pot. The key is to preheat the board to start the activation of the flux yet not burn it up prior to reaching the solder pot.
Leaded solders (Sn63Pb37) will require a dwell time of 2-4 seconds. Lead-free solders (Sn96.***g3.0Cu0.5) will require a dwell time in the wave of 4-8 seconds. The conveyor speed should be adjusted to accomplish the proper contact time then the preheat zones set to accomplish the proper preheating temperatures. If there is any questions please contact Kester Technical Support. Touch-Up Application