UV LED Performance Tackling More Manufacturing Applications

UV LEDs are increasing being used in manufacturing to replace mercury lamps for applications like UV curing and lithography. UV-A/B LED curing is production‑ready in many industrial segments, while deep UV‑C LED curing is still emerging and application‑specific rather than a drop‑in replacement for mercury sources, across the board.

For UV‑A/UV‑B curing (inks, coatings, adhesives), LED is now mainstream and often the preferred choice over mercury.

• Narrowband 365–405 nm LED systems deliver sufficient irradiance for high‑speed curing in printing, electronics, and coatings when chemistries are matched to the LED spectrum.
• Benefits like instant on/off, 20,000+ hour lifetimes, lower heat load, and no mercury/ozone make LED better aligned with modern production and environmental regulations.

For UV‑A curing, LED performance is generally “good enough” or superior if the process is reformulated.

• Mercury lamps provide a broad spectrum (UVC–UVA) that can help with surface cure and legacy chemistries, while LEDs provide targeted peaks that improve efficiency but demand LED‑tuned photoinitiators.
• Many operations see 50%+ energy savings, reduced maintenance, and smaller equipment footprints, so the main barriers are capex and requalification rather than core performance.

Deep UV‑C LEDs are improving but are not yet a universal industrial curing light source.

• State‑of‑the‑art commercial UVC LEDs still have low external quantum efficiencies (typically below 4%), though >10,000 h L70 lifetimes are now being demonstrated, and selected devices have reached >10% wall‑plug efficiency at 265 nm in lab‑validated products.
• These performance levels support disinfection and some niche UV‑C curing or surface‑treat applications, but power density and cost remain limiting compared with traditional mercury systems for large‑area, high‑throughput curing.

Nichia, a major producer of UV LEDs has announced the launch of its “Mercury-Free Project,” an initiative to replace mercury lamps used within Nichia with LED technology. Nichia has replaced some of the UV mercury lamps used in its LED manufacturing process, where LED conversion had not previously been feasible, with UV LED light sources. In November 2025, Nichia began operations on certain production lines.

Along with improving UV LED output, the use of advanced optical technology has enabled high irradiance that was previously a challenge, making light source replacement possible. In addition to being mercury-free, this change has achieved a 35% reduction in CO₂ emissions per light source. This also contributes to reducing maintenance work and the frequency of light source replacement, as well as minimizing waste containing mercury.

Recent technological innovations have made UV LEDs a practical alternative to UV mercury lamps. Moving forward, Nichia plans to replace light sources in all applications that currently use mercury lamps, including lithography and curing processes, and is committed to realizing mercury-free and carbon neutral manufacturing.

More information is available here.

Image above courtesy of Nichia.

David Shiller

David Shiller is the Publisher of LightNOW, and President of Lighting Solution Development, a North American consulting firm providing business development services to advanced lighting manufacturers. The ALA awarded David the Pillar of the Industry Award. David has co-chaired ALA’s Engineering Committee since 2010. David established MaxLite’s OEM component sales into a multi-million dollar division. He invented GU24 lamps while leading ENERGY STAR lighting programs for the US EPA. David has been published in leading lighting publications, including LD+A, enLIGHTenment Magazine, LEDs Magazine, and more.

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