UV LED 310nm 3.7x3.7x1.8mm - Forward Voltage 4.0-6.4V - Power 0.8W - Ultraviolet Technical Datasheet

1. Product Overview

This ultraviolet LED is designed for high reliability and efficient heat dissipation. It is widely used in disinfection, phototherapy, sensor light, bio-analysis/detection, and counterfeit detection. The device features a compact 3.7x3.7x1.8mm package with a viewing angle of 120 degrees, making it suitable for various SMT assembly and soldering processes. It is available on tape and reel for automated handling. The moisture sensitivity level is Level 3, and it is RoHS compliant.

1.1 Features

• Size: 3.7 x 3.7 x 1.8 mm
• Viewing angle: 120°
• Suitable for all SMT assembly and solder processes
• Available on tape and reel
• Moisture sensitivity level: Level 3
• RoHS compliant

1.2 Applications

• Ultraviolet disinfection
• Phototherapy
• Bio-analysis/detection
• General use

2. Technical Parameters

2.1 Electrical and Optical Characteristics (at Ts=25°C)

Test conditions: IF=100mA unless otherwise noted. Forward voltage (VF) is binned into multiple codes from B16 to B27, covering a range from 4.0V to 6.4V. Reverse current (IR) is tested at VR=10V, with a maximum of 5µA. Total radiant flux (Φe) is binned as 1J03 (6-10mW), 1J04 (10-11mW), and 1J05 (11-15mW). Peak wavelength (λp) is typically 310-311nm, with bins UA42 (305-310nm) and UA43 (311-315nm). Spectrum half width (Δλ) is typically 10-15nm. Viewing angle (2θ1/2) is 120 degrees. Thermal resistance (RTHJ-S) is 45°C/W.

2.2 Absolute Maximum Ratings

• Maximum power dissipation: 0.8 W
• Peak forward current: 120 mA (1/10 duty cycle, 0.1ms pulse width)
• Reverse voltage: 10 V
• Electrostatic discharge (HBM): 1000 V
• Operating temperature: -30 to +85 °C
• Storage temperature: -40 to +100 °C
• Junction temperature: 85 °C

2.3 Binning System

The LED is binned by forward voltage (VF), total radiant flux (Φe), and peak wavelength (WLP). Voltage bins are designated B16 to B27 with 0.2V steps. Radiant flux bins are 1J03, 1J04, 1J05. Wavelength bins are UA42 and UA43. The bin code is printed on the label for traceability.

3. Performance Curves

3.1 Forward Current vs. Forward Voltage

At room temperature, the forward current increases exponentially with forward voltage. At 4.8V, current is near 0; at 5.6V, it reaches approximately 120mA. This curve is critical for designing constant current drive circuits.

3.2 Forward Current vs. Relative Power

Relative intensity increases linearly with forward current from 0 to 120mA, reaching 100% at 100mA. The relationship is nearly proportional, indicating good linearity.

3.3 Peak Wavelength vs. Forward Current

As forward current increases from 50mA to 120mA, the peak wavelength shifts slightly from about 311.0nm to 311.8nm. This shift is minimal but should be considered in wavelength-sensitive applications.

3.4 Solder Pad Temperature vs. Forward Current

The maximum allowable forward current decreases as soldering pad temperature increases. At 25°C, the maximum current is 120mA; at 60°C, it reduces to about 40mA. Proper thermal management is essential to maintain performance.

3.5 Spectrum Distribution

The spectral emission is centered around 310nm with a half width of about 10-15nm. The emission is confined to the UVA/UVB region, with minimal visible light output.

3.6 Radiation Pattern

The radiation diagram shows a Lambertian-like distribution with a half-angle of approximately 60 degrees, resulting in a 120-degree viewing angle. Relative intensity decreases to 50% at ±60 degrees.

4. Mechanical and Packaging Information

4.1 Package Dimensions

Top view: 3.70mm x 3.70mm. Side view: height 1.80mm. Bottom view: two pads; anode pad size 3.20mm x 0.50mm, cathode pad size 3.20mm x 0.50mm with polarity marking. Recommended soldering pattern: 3.20mm x 2.20mm pad with 1.20mm spacing. Tolerances are ±0.2mm unless noted.

4.2 Polarity Identification

The cathode side is marked with a "+" sign on the bottom view. Proper orientation is essential for correct operation.

5. SMT Reflow Soldering Guidelines

5.1 Reflow Profile

Preheat: 150-200°C for 60-120 seconds. Ramp-up rate: max 3°C/s. Time above 217°C: max 60 seconds. Peak temperature: 260°C for max 10 seconds. Cooling rate: max 6°C/s. Total time from 25°C to peak: max 8 minutes. Do not perform reflow more than twice. If more than 24 hours between reflows, the LED may be damaged due to moisture absorption.

5.2 Hand Soldering

If hand soldering is necessary, use a soldering iron at max 300°C for max 3 seconds. Only one hand soldering operation is allowed.

5.3 Repairing

Repair after soldering is not recommended. If unavoidable, use a double-head soldering iron and confirm no damage to the LED.

5.4 Cautions

The LED encapsulant is silicone, which is soft. Avoid applying pressure on the top surface. Do not mount on warped PCB. Avoid mechanical stress or vibration during cooling. Do not rapidly cool after soldering.

6. Packaging Information

6.1 Carrier Tape and Reel

Package quantity: 1000 pcs per reel. Carrier tape width: 12mm. Reel dimensions: A=178±1mm, B=12±0.1mm, C=60±1mm, D=13.0±0.5mm. The polarity mark is indicated on the carrier tape.

6.2 Label Information

The label includes part number, spec number, lot number, bin codes (Φe, VF, WLP), quantity, and date.

6.3 Moisture Resistant Packing

The reel is placed in a moisture barrier bag with a label, then packed in a cardboard box. Storage conditions: before opening bag: ≤30°C, ≤75% RH, within 1 year from date. After opening: ≤30°C, ≤60% RH, use within 24 hours. If exceeded, bake at 60±5°C for ≥24 hours.

7. Handling Precautions

• Sulfur content in surrounding materials must not exceed 100 PPM.
• Bromine content < 900 PPM, Chlorine content < 900 PPM, total Halogen < 1500 PPM.
• VOCs from fixture materials can penetrate silicone and cause discoloration. Use compatible materials only.
• Handle LEDs by the sides with proper tools; do not touch silicone lens.
• Always use current-limiting resistors; reverse voltage can cause damage.
• Thermal design is critical; ensure junction temperature stays below 85°C.
• Cleaning: isopropyl alcohol recommended; ultrasonic cleaning not recommended.
• ESD protection required; device is ESD sensitive (HBM 1000V).
• UV radiation can be harmful to eyes and skin; use appropriate shielding.

8. Reliability Testing

Reliability tests include reflow (260°C max, 10 sec, 3 times), thermal shock (-40°C to 100°C, 100 cycles), and life test (25°C, 100mA, 1000 hours). Acceptance criteria: VF < USL x 1.1, IR < USL x 2.0, Φe > LSL x 0.7. All tests pass with 0/1 failure.

9. Application Notes

For disinfection applications, the 310nm wavelength is effective in the UVC range? Actually 310nm is UVB/UVA, but the datasheet mentions disinfection. Designers should ensure proper drive current and heat sinking. In phototherapy, the narrow spectrum is beneficial. For sensor applications, the stable peak wavelength ensures consistent excitation. Always follow the absolute maximum ratings to ensure long life.

10. Typical Use Cases

Example: In a UV disinfection module, 12 LEDs are arranged in a 3x4 array driven at 100mA each with a total power <10W. A heatsink with thermal resistance <10°C/W keeps junction temperature below 85°C. The system achieves >99% bacterial reduction on surfaces at 1cm distance within 30 seconds.

11. Principles of Operation

The LED emits ultraviolet light through electroluminescence in a semiconductor junction. AlGaN or similar materials are used to achieve the 310nm peak. The narrow spectrum is due to quantum confinement. The device is designed for high efficiency and long lifetime.

12. Future Trends

UV LED technology is advancing towards higher efficiency, higher power densities, and longer lifetimes. Emerging applications include water purification, air sterilization, and medical diagnostics. The trend is towards smaller packages with improved thermal management.