Tungsten Wire for Photovoltaic Slicing: Diameters, Purity, and Buyer Checklist

Photovoltaic wafer slicing has moved decisively toward diamond wire sawing (DWS), and the mother wire onto which the diamond abrasive is electroplated is increasingly drawn from high-purity tungsten in place of steel cores. Tungsten carries higher tensile strength at equal or smaller diameter, which lets the wire survive the tension and abrasion of high-speed slicing loops while enabling thinner wafers.

For slicing-line operators, the wire is a consumable whose consistency directly drives kerf loss, breakage rate, and wafer surface quality. That is why diameter control and batch uniformity matter more than any single headline specification.

Common promoted diameters for PV mother wire sit in the fine range — for example 0.035 mm, 0.037 mm, 0.10 mm, and 0.11 mm. As diameter decreases, less silicon is removed per cut (lower kerf loss) and more wafers per ingot, but wire tension management and breakage risk become more demanding.

Chinese tungsten wire grades are commonly referenced as W1 (≥ 99.95% W) and W2 (≥ 99.92% W). For PV slicing, buyers typically specify the higher-purity grade to limit inclusions that can initiate wire breaks, and to stabilize drawing and annealing behavior through the spool.

Purity interacts with surface finish: a clean, uniform surface reduces friction in the slicing loop and supports more consistent diamond coating adhesion for coated-wire processes.

When requesting quotation, the details that shorten technical review are the same ones that predict slicing performance:

Photovoltaic tungsten wire is specified by diameter consistency, purity grade, and spool-level uniformity. Buyers who fix these three variables early — and share consumption volume — get quotations that translate into stable slicing-line performance.