KESTER 951 Soldering Flux

Harmonization Code : 29051200 | Propan-1-ol (propyl alcohol) and propan-2-ol (isopropyl alcohol)

Main features

Zero-halogen, non-rosin formula
High Surface Insulation Resistance (SIR)
Minimizes defects

Product Description

KESTER 951 is a zero-halogen, non-rosin flux engineered for high-reliability soldering processes, including wave soldering and for use on conventional and surface mount circuit board assemblies. Its extremely low solids content (2.0%) and unique activator system ensure practically no residue is left on the assembly after soldering. Boards exit the wave solder machine dry and cosmetically clean. This "no-clean" formulation eliminates residues that could interfere with electrical testing.

KESTER 951 is suitable for applications requiring maximum reliability, such as in the automotive, computer, and telecommunications industries. 951 delivers improved soldering performance, helping to minimize common defects like solder bridges (shorts) and excessive solder. It also provides superior surface insulation resistance (SIR) on soldered boards compared to typical water-soluble fluxes. Additionally, 951 contains a corrosion inhibitor to prevent the formation of corrosion products, even when bare copper surfaces are exposed to humid environments

Product Key Features

Residue-free boards do not interfere with electrical testing and exhibit high Surface Insulation Resistance (SIR).
Improves soldering performance to reduce solder bridges (shorts) and excessive solder.
Contains an inhibitor that prevents corrosion on exposed bare copper surfaces in humid conditions.

Applications

Ideal for applications requiring high reliability, such as automotive, computer, and telecommunications circuit board assemblies.

Specifications
Additional Information

Technical Specifications

General Properties
Solids	2 %
Specific Gravity Specific Gravity Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume. For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless.	0.814

Additional Information

Flux Application

951 can be applied to circuit boards by a spray, foam, or dip process. Flux deposition should be 120 to 240ug of solids/cm² (750 to 1500ug of solids/in²). An air knife after the flux tank is recommended to remove excess flux from the circuit board and prevent dripping on the preheater surface when used in a foam or wave application.