3535 UV-C LED

Updated: 2026-09-12

Overview

The 3535 UV-C LED represents a standardized form factor (3.5mm x 3.5mm) for high-efficiency ultraviolet disinfection components. These LEDs operate within the 265-280nm germicidal range, where DNA/RNA absorption peaks, enabling effective pathogen deactivation. Compared to traditional mercury lamps, they offer instant on/off capability, directional emission, and compact system integration. Major manufacturers typically employ flip-chip or vertical structure designs to enhance light extraction and thermal performance. The 3535 package designation ensures mechanical compatibility with automated SMT assembly processes, making it suitable for high-volume production of sterilization devices across healthcare, food safety, and consumer appliance sectors.

Structure and Working Principle

Internally, 3535 UV-C LEDs contain aluminum gallium nitride (AlGaN) semiconductor layers grown on specialized substrates like aluminum nitride or patterned sapphire. When forward voltage is applied (typically 6-7V), electron-hole recombination generates photons at UV-C wavelengths. The ceramic package incorporates a quartz or high-transmission glass window to minimize optical losses. Thermal management is critical, with most designs achieving <10°C/W thermal resistance through direct copper bonding or thermal vias. Advanced versions may integrate photodiodes for real-time output monitoring. The hermetic sealing prevents moisture ingress that could degrade the LED chip or phosphor-free wavelength conversion materials.

Key Features

Wavelength consistency is paramount, with top-grade 3535 UV-C LEDs maintaining ±3nm deviation from peak emission. Typical radiant flux ranges from 10-50mW at 350mA drive current, with wall-plug efficiency around 3-5%. The beam angle usually spans 120-140 degrees for broad surface coverage. Durability features include 8kV ESD protection and >10,000-hour lifespan (L70 criteria). Some variants incorporate reflectors to increase irradiance. Unlike 3030 or 5050 packages, the 3535 size optimizes the balance between power density and thermal dissipation for continuous operation in compact disinfection systems.

Application Areas

Primary applications include point-of-use water purifiers (flow rates <1L/min), where 3535 LEDs provide sufficient irradiance to achieve 99.9% pathogen reduction. HVAC systems integrate them for airborne microbe control, often in arrays with aluminum heat sinks. Portable sterilization wands leverage their compact size for spot treatment of surfaces. Medical device manufacturers utilize these LEDs for instrument disinfection cabinets and wearable infection prevention tools. Emerging uses include 3D printer chamber sterilization and agricultural produce treatment. Industrial settings deploy them in conveyor-based packaging line sanitization, typically requiring custom lens optics to focus the UV output.

Maintenance and Precautions

Regular inspection of the quartz window is necessary to prevent dust accumulation that can block UV transmission. Thermal paste should be reapplied every 2-3 years in high-power applications. Drive currents must not exceed manufacturer specifications to avoid rapid lumen depreciation. Safety protocols mandate interlock switches to deactivate LEDs during human-accessible operations. Polycarbonate enclosures should be avoided as they absorb UV-C; instead, PTFE or specialized acrylics are recommended for light guides. Proper grounding is essential to prevent electromagnetic interference with sensitive medical or laboratory equipment.

B2B Procurement Guide

When sourcing 3535 UV-C LEDs, request IEC 62471 photobiological safety reports and LM-80 lifespan data. Verify RoHS/REACH compliance certificates, especially regarding lead-free soldering compatibility. For OEM designs, check mechanical drawings for pad layout variations among suppliers. Sample testing should include spectral radiometry under rated current and thermal cycling from -20°C to +85°C. Consider ordering pre-mounted on MCPCBs for small-batch prototyping. Minimum order quantities typically start at 1,000 pieces, with 8-12 week lead times for custom wavelength bins. Some manufacturers offer pre-configured arrays with driver circuits for faster integration.