UV LED RF-C37P6-URF-AR Specifications - Size 3.7x3.7x3.45mm - Forward Voltage 4.5-7.5V - Power 3.8W - Peak Wavelength 275nm - English Technical Document

1. Product Overview

This document presents the detailed technical specifications for a high-reliability, high-power ultraviolet (UV) LED designed for disinfection, sterilization, and air purification applications. The device features a compact 3.7mm x 3.7mm x 3.45mm surface-mount package with a 60-degree viewing angle, enabling efficient integration into various electronic assemblies. The product is RoHS compliant and classified as moisture sensitivity level 3, ensuring compatibility with standard SMT assembly and reflow soldering processes. With a maximum power dissipation of 3.8W and forward voltage options ranging from 4.5V to 7.5V at 350mA, this UV LED delivers reliable performance in demanding environments.

2. Technical Parameter Deep Dive

2.1 Optoelectronic Characteristics (at 25°C, 350mA)

The forward voltage (VF) is specified in four bins: F02 (4.5-5.5V), F03 (5.5-6.5V with typical 6.3V), F04 (6.5-7.5V). The reverse current (IR) at VR=10V is minimal, with bins 1H05 to 1H08 covering 5µA to 40µA. Total radiant flux (Φe) ranges from 270mW to 275mW (bin UA35) or 275-280mW (bin UA36). Peak wavelength (λp) is 275nm typical (range 270-280nm). Spectrum half width (Δλ) is 8-12nm, viewing angle 60°, and thermal resistance (RTHJ-S) is 45°C/W maximum.

2.2 Absolute Maximum Ratings

The maximum power dissipation is 3.8W, peak forward current (1/10 duty, 0.1ms pulse) is 500mA, reverse voltage is 10V. Electrostatic discharge (HBM) withstands 1000V. Operating temperature range is -40°C to +45°C, storage -20°C to +65°C, junction temperature 60°C maximum. Care must be taken to ensure junction temperature does not exceed this limit during operation.

2.3 Binning System

The product is sorted by forward voltage (F02-F04), reverse current (1H05-1H08), and radiant flux (UA35, UA36). Peak wavelength is centered at 275nm with a tolerance of ±2nm. Measurement tolerances: VF ±0.1V, wavelength ±2nm, radiant flux ±10%. Customers should select appropriate bins based on their system requirements.

3. Performance Curve Analysis

3.1 Forward Voltage vs. Forward Current

The I-V curve shows a typical forward voltage of approximately 6.1V at 350mA, with a steep slope indicating low dynamic resistance. At 100mA, VF drops to about 5.9V; at 500mA, it rises to about 6.5V.

3.2 Relative Power vs. Forward Current

Relative intensity increases nearly linearly with current from 0 to 500mA, reaching about 150% of the value at 350mA when operating at 500mA. This allows for brief overdriving within limits.

3.3 Peak Wavelength vs. Forward Current

The peak wavelength shifts slightly with current: at 100mA, λp ≈ 274.0nm; at 500mA, λp ≈ 274.8nm. This shift is minor (about 0.8nm) over the entire current range, indicating good wavelength stability.

3.4 Temperature Dependence

Maximum forward current derates as solder point temperature increases: at Ts=25°C, maximum current is 500mA; at Ts=50°C, it reduces to ~300mA; at Ts=100°C, current should be zero. Proper thermal management is essential to maintain performance.

3.5 Spectrum Distribution

The spectral distribution is centered around 275nm with a full width at half maximum of about 10nm. The output is predominantly in the UVC range (200-280nm), making it effective for germicidal applications.

3.6 Radiation Pattern

The radiation diagram shows a Lambertian-like pattern with intensity dropping to 50% at approximately ±30° and near zero at ±90°. This provides a uniform illumination angle of 60°.

4. Mechanical and Package Information

4.1 Package Dimensions

The top view shows a 3.70mm x 3.70mm body with a height of 3.45mm. The side view indicates a central lens height of 1.20mm above the base. The bottom view reveals two large thermal/electrical pads: the anode pad is 3.20mm x 2.20mm, the cathode pad is 3.20mm x 1.20mm, both separated by 0.50mm gaps. Polarity is marked on the bottom.

4.2 Soldering Pattern (Recommended Pad Design)

Recommended PCB land pattern: anode pad 3.70mm x 3.20mm, cathode pad 3.70mm x 1.20mm, with 0.50mm spacing between them. This ensures good thermal and electrical contact. All dimensions in millimeters with ±0.2mm tolerance unless otherwise noted.

4.3 Polarity Identification

Polarity is indicated on the bottom view by a "+" marking on the anode side. The device is also marked with a polarity mark on the carrier tape.

5. Soldering and Assembly Guidelines

5.1 Reflow Soldering Profile

The recommended reflow profile: preheat from 150°C to 200°C for 60-120 seconds, ramp-up to 217°C (TL) within 60 seconds maximum, then peak temperature 260°C for up to 10 seconds (tp). Cooling rate should not exceed 6°C/s. Total time from 25°C to peak should be within 8 minutes. Do not exceed two reflow cycles; if more than 24 hours elapse between cycles, bake the LEDs first.

5.2 Hand Soldering

Hand soldering: iron temperature below 300°C for less than 3 seconds, one time only. Do not apply pressure to the silicone lens during soldering.

5.3 Repair and Rework

Repair after soldering is not recommended. If unavoidable, use a double-head soldering iron and verify LED characteristics remain intact.

5.4 Handling Precautions

The LED's silicone encapsulant is soft; avoid mechanical stress on the top surface. Do not mount on warped PCBs or bend the board after soldering. Avoid rapid cooling. Use proper ESD precautions (the device passes 1000V HBM, but protection is still required).

6. Packaging and Ordering Information

6.1 Packaging Specifications

Units are packaged on tape and reel: 500 pieces per reel. Carrier tape pitch 4.0mm, width 12.0mm, with a pocket size accommodating the 3.7mm body. Reel diameter 178mm, width 12mm, hub diameter 60mm, spindle hole 13.0mm.

6.2 Label Information

Each reel carries a label with: Part Number, Spec Number, Lot Number, Bin Code (including Φe, VF, WLP bins), Quantity, and Date. The label also includes the ESD caution symbol.

6.3 Moisture Barrier Packaging

The reel is sealed in a moisture barrier bag with a desiccant and humidity indicator card. Storage before opening: ≤30°C, ≤75%RH for up to 1 year. After opening: ≤30°C, ≤60%RH for 24 hours. If exceeded, bake at 60±5°C for ≥24 hours.

7. Application Recommendations

7.1 Typical Applications

This UV LED is optimized for disinfection (water, air, surfaces), sterilization of medical equipment, and air purification systems. Its compact size and high radiant flux enable integration into portable and fixed installations.

7.2 Design Considerations

For reliable operation, ensure adequate heat sinking: the thermal resistance of 45°C/W means that at 3.8W, the junction-to-solder-point temperature rise is 171°C, which exceeds the 60°C junction limit. Therefore, actual power must be derated (e.g., 350mA yields about 2.2W, giving 99°C rise, still exceeding limits; proper thermal management is critical). Use series resistors or constant-current drivers to prevent thermal runaway. Avoid reverse voltage conditions.

7.3 Material Compatibility

The LED is sensitive to sulfur, bromine, chlorine, and volatile organic compounds (VOCs). Ensure surrounding materials contain <100ppm sulfur, <900ppm of bromine and chlorine each, and total halogens <1500ppm. Avoid adhesives that outgas organic vapors.

8. Reliability and Testing

8.1 Reliability Test Items

The product has passed: reflow soldering (260°C, 3 times), thermal shock (-40°C to 100°C, 100 cycles), and life test (25°C, 350mA, 1000 hours). All with acceptance criteria 0/1 (zero failures allowed). Failure criteria: VF > U.S.L.×1.1, IR > U.S.L.×2.0, Φe < L.S.L.×0.7.

8.2 Storage and Handling

Store in original packaging under controlled conditions. After opening, use within 24 hours or bake before use. Handle with ESD protection and avoid touching the lens.

9. Technical Comparison

Compared to standard SMD UV LEDs, this product offers a balanced combination of high power (3.8W max) and compact footprint (3.7x3.7mm). The 60° viewing angle is wider than many deep-UV LEDs (typically 30-45°), providing broader coverage. The thermal resistance of 45°C/W is competitive for this package size. Forward voltage bins allow selection for specific driver voltages (e.g., 6V or 12V systems). The radiant flux of ~275mW at 350mA is typical for UVC LEDs in this package, suitable for disinfection applications.

10. Frequently Asked Questions

1. What is the peak wavelength? The peak wavelength is centered at 275nm (typical), within the UVC germicidal range.
2. Can I use this LED at 500mA continuously? No, the absolute maximum rating of 500mA is for pulses (0.1ms, 10% duty). Continuous operation at 500mA would exceed the junction temperature limit unless extraordinary cooling is provided.
3. What is the recommended drive current? 350mA is the typical test condition and recommended for continuous operation with proper heat sinking. Lower currents (e.g., 200-300mA) improve lifetime and efficiency.
4. Does this LED require a heatsink? Yes, due to the high power dissipation and thermal resistance, a heatsink or thermal pad is essential to keep the solder point temperature below 45°C at 350mA.
5. What is the binning for forward voltage? Bins F02 (4.5-5.5V), F03 (5.5-6.5V), F04 (6.5-7.5V). Use appropriate current-limiting components for your supply voltage.
6. Can I use this for water disinfection? Yes, the 275nm wavelength is effective for inactivating bacteria and viruses in water, provided the design includes proper optical coupling and cooling.

11. Practical Application Examples

11.1 Air Purification Unit

An air purifier using this UV LED can be designed with a simple constant-current driver at 350mA and a small heatsink attached to a metal enclosure. The 60° beam angle allows even irradiation of a photocatalytic filter. For a small room unit, one or two LEDs suffice.

11.2 Portable Sterilizer Wand

Battery-powered sterilizer: use three LEDs in series with a boost converter to provide ~18V at 350mA. The compact package (3.7mm) enables a slim wand design. Include a quartz window and proximity sensor for safety.

11.3 Surface Disinfection Module

For conveyor belt sterilization, arrays of these LEDs can be tiled. With a pitch of 12mm on tape, arrays can be designed to cover a 100mm wide belt. Proper thermal management via an aluminum substrate is needed.

12. Principle Introduction

UVC LEDs generate light through electroluminescence in a semiconductor material (typically AlGaN). When a forward voltage is applied, electrons and holes recombine in the active region, emitting photons with energy corresponding to the bandgap. The 275nm wavelength corresponds to photon energy of about 4.5eV. The deep ultraviolet light damages the DNA/RNA of microorganisms, preventing replication and causing inactivation. This physical principle underlies disinfection applications.

13. Development Trends

The UVC LED market is evolving toward higher efficiency (WPE >5% currently, aiming for >10%), longer lifetimes (>10,000 hours), and lower cost per mW. Package sizes are shrinking while maintaining power. This 3.7mm package represents a mature design; future trends include chip-scale packages and integrated optics. Additionally, toxicity concerns of mercury lamps are driving adoption of LED-based UV systems across medical, industrial, and consumer markets.