LFM-62 / LFM-22H lead-free solder bars for wave and selective soldering

Technical specifications

Specifications are taken from the manufacturer’s technical documentation. Updated 11/13/2026.

Description

Lead-free, silver-free bars for wave, flow and selective soldering systems, made from the copper-rich SnCuNi alloy Sn-3.0Cu-0.5Ni (tin with 3.0 % copper and 0.5 % nickel). The grades are LFM-62 and LFM-22H. This three-metal alloy is designed to minimise copper leaching and is particularly suited to fine copper wires and pads. Its melting range is 228–394 °C, and it contains an anti-oxidation agent for high-temperature dip soldering. Shelf life is 36 months.

During soldering, the copper base material dissolves into the molten solder, and lead-free solders make this worse. How much copper is lost depends on the solder alloy, the soldering temperature and the soldering time. The risk is greatest with fine copper wires and pads, where the cross-section is so small that partial loss directly endangers the joint. In one example, a copper wire at 350 °C kept 69 % of its material after 1 second and only 18 % after 5 seconds.

In a dip-soldering comparison at 400 °C, LFM-62 retained 83.4 % of the copper wire, the best value of all alloys tested. The other results at 400 °C were LFM-59 (Sn-3.0Cu) 78.5 %, Sn-37Pb 47.1 %, LFM-41 (Sn-0.3Ag-2.0Cu) 45.1 %, Sn-0.7Cu 33.9 %, Sn-3.0Ag-0.5Cu (SAC305) 27.3 % and Sn-3.5Ag-0.7Cu 24.0 %. At 350 °C, LFM-41 retained 66.5 %, Sn-37Pb 63.6 %, Sn-3.0Ag-0.5Cu 56.0 %, Sn-0.7Cu 52.2 % and Sn-3.5Ag-0.7Cu 46.6 %. Only 400 °C values are given for LFM-59 and LFM-62. In the test, a 150 µm copper wire was coated with flux, dipped for 2 seconds, and then measured for remaining copper using cross-section micrographs. Higher values mean less copper loss.

The anti-oxidation agent reduces the residues formed during high-temperature dip soldering, which lowers flux consumption. Dross formation is low and bath service life is long.

LFM-62 belongs to a family of three alloys against copper leaching, all with compatible fluxes: - LFM-41 (Sn-0.3Ag-2.0Cu, 217–270 °C) is low-silver with increased copper content and has the lowest melting range. It is also available as cored wire with the fluxes SR-37, SR-LA and SRS-UL. - LFM-59 (Sn-3.0Cu, 227–312 °C) is silver-free and contains an anti-oxidation agent. - LFM-62 adds nickel to the copper-rich alloy, which raises the protection further.

Which alloy fits a given process depends on soldering temperature, soldering time and wire diameter, as well as bath temperature, the copper content of the assemblies and the required bath service life.

Available forms: - Bar: LFM-62H, item 80002002, 1.0 kg carton. - Solid wire without flux core, on spools: item 80002915 (1.6 mm, 0.8 kg), item 80002910 (2.0 mm, 1.6 kg) and item 80002930 (3.0 mm, 3.0 kg).

Other pack sizes are available on request.