KESTER 977 Soldering Flux

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

Main features

Biodegradable at pH ≥ 2.0
Compatible with most solder masks and laminates
Does not degrade SIR

Product Description

KESTER 977 is an advanced, organic, water-based, no-clean flux designed for achieving high-quality soldering results on electronic circuit board assemblies. This chemistry excels in wave soldering applications, providing reliable performance across most common surface finishes.

KESTER 977 was specifically formulated to address common challenges in VOC-free, no-clean systems by significantly reducing solder bridging, ensuring cleaner, more reliable joints and improved productivity without compromising the long-term reliability of the assembly.

Product Key Features

Leaves a minimal, non-conductive, and non-corrosive residue that typically does not require cleaning.
Biodegradable at pH 2.0 or greater
Residues will not attack properly cured solder masks or FR-4 Epoxy-Glass laminate.
Does not negatively impact the Surface Insulation Resistance (SIR) of the soldered assembly.

Applications

Suitable for wave soldering applications & high-throughput processes requiring high reliability.

Note: Due to changes in REACH Regulations, this product is no longer sold into Europe or to European customers.

Specifications
Additional Information

Technical Specifications

General Properties
Solids	3.25 %
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.	1.012