The Kester 83-1000-0186 , under MIL-F-14256, was QPL approved as Type RMA. Although the fluxing ability approaches that of Type RA flux, the flux residue after soldering is non-corrosive and non-conductive. Kester 186 rosin flux has been developed for use in critical applications where difficult assemblies are to be soldered, but process requirements stipulate use of Type RMA flux. This flux possess high thermal stability for soldering multi-layer assemblies which require a high preheat temperature. Exposure to high preheat temperatures does not degrade solubility of the residue in normal cleaning solvents. There is no surface insulation resistance degradation caused by the flux residue. The use of a minimum of ionic activating agents and the inactive nature of the residue permits leaving the residue on circuitboard assemblies for many applications. The flux residue is also moisture and fungus resistant.
Performance Characteristics:
• High thermal stability
• Improves soldering performance
• Eliminates the need and expense of cleaning
• Classified as ROL0 per J-STD-004
RoHS Compliance
This product meets the requirements of the RoHS (Restriction of Hazardous Substances) Directive, 2002/95/EC Article 4 for the stated banned substances.
Application Notes
Flux Application:
Kester 186 can be applied to
circuit boards by a foam or dip process. An air knife after the flux tank is recommended
to remove excess flux from the circuit board and prevent dripping on the
preheater surface.
Process Considerations:
The optimum preheat temperature
for most circuit assemblies is 90-105°C (194-221°F) as measured on the top or
component side of the printed circuit board. Dwell time in the wave is
typically 2-4 seconds. The wave soldering speed should be adjusted to
accomplish proper preheating and evaporate excess solvent which could cause
spattering. For best results, speeds of 1.1-1.8 m/min (3½-6 ft/min) are used.
The surface tension has been adjusted to help the flux form a thin film on the
board surface allowing rapid solvent evaporation.
Flux Control:
Specific gravity is normally
the most reliable method to control the flux concentration of rosin-based
fluxes. To check concentration, a hydrometer should be used. Control of the
flux in the foam flux tank during use is necessary for assurance of consistent
flux distribution on the circuit boards. The complex nature of the solvent
system for the flux makes it imperative that Kester 120 Thinner be used to
replace evaporative losses. When excessive debris from circuit boards, such as
board fibers and from the air line build up in the flux tank, these
particulates will redeposit on the circuit boards which may create a build-up
of residues on probe test pins. It is, therefore, necessary to clean the tank
and then replenish it with fresh flux when excessive debris accumulates in the
flux tank.
Cleaning:
Kester 186 flux residues are
non-conductive, non-corrosive and do not require removal in most applications.
Storage and Shelf Life:
Kester 186 is flammable.
Store away from sources of ignition. Shelf life is 2 years from date of
manufacture when handled properly and held at 10-25°C (50-77°F).
Health & Safety:
This product, during handling
or use, may be hazardous to health or the environment. Read the Material Safety
Data Sheet and warning label before using this product.
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