3W SMD High Power UV LED Bead - 365nm to 370nm Ultraviolet UVA Emitter

Specifications:

• Wavelength: 365nm - 370nm (UVA Spectrum)
  
• Power Dissipation: 3 Watts
  
• Forward Voltage (VF): 3.4V – 3.8V DC
  
• Forward Current (IF): 700mA (Constant Current Recommended)
  
• Radiant Flux: 600mW – 800mW
  
• Viewing Angle: 120° – 140° (Lambertian Emitter)
  
• Chip Material: InGaN on Ceramic Substrate
  
• Operating Temperature: -40°C to +80°C (requires active cooling)

Key Applications & Projects

• Industrial UV Curing: Instant bonding for medical-grade plastics, optics, and 3D printing resins.
  
• Forensic Investigation: High-contrast detection of bodily fluids, counterfeit currency, and security markers.
  
• Leak Detection: Used with UV-fluorescent dyes to find micro-cracks in HVAC and automotive systems.
  
• Mineralogy: Identifying fluorescent minerals that do not react to standard 395nm light.
  
• Scientific Research: Fluorescence microscopy and sterilization studies.

Project Evolution 

• Past Projects (Prerequisites): If you’ve previously used standard 5mm UV LEDs or 395nm strips and found the "glow" insufficient or the cure time too slow, this is your next step.
  
• Feature Upgrade: Transitioning to this 3W 365nm emitter unlocks deep-layer penetration. It allows you to cure several millimeters of clear resin at once, preventing "skinning" (where the top is hard but the bottom is liquid).
  
• Effort/Requirements: Intermediate. You will need a constant current LED driver (700mA) and a proper aluminum heat sink (star PCB) to manage the heat.

Virtual Technician & Wiring

• ⚠️ CRITICAL WARNING: This LED generates intense UV radiation. Never stare directly at the beam, even with sunglasses. Use UV-rated polycarbonate safety goggles.
• Heat Management: Do NOT operate for more than 5 seconds without an aluminum heat sink. The chip will overheat and fail permanently.

Wiring Guide:

• Anode (+): Connect to the positive terminal of a 700mA Constant Current Driver.
• Cathode (-): Connect to the negative terminal of the driver.
• Voltage Note: If using a 5V/12V supply, you MUST use a current-limiting
• resistor or a buck-converter LED driver to maintain 700mA.

​Packages include:

1 X 3W SMD High Power UV LED Bead - 365nm to 370nm Ultraviolet UVA Emitter

Frequently Asked Questions (FAQ)

1. Why is 365nm better than 395nm for curing?
   365nm provides higher photon energy, which better matches the absorption peaks of industrial photoinitiators, ensuring a faster, deeper cure.
2. Can I run this directly off a 3.7V Li-ion battery?
   While the voltage matches, a direct connection is dangerous. As the LED heats up, it will draw more current (thermal runaway) and burn out. Use a driver.
3. Does this LED look dim to the human eye?
   Yes. Much of the 365nm output is invisible to humans. It will look like a faint "dull purple," but the actual radiant energy is very high.
4. Will this work for curing UV nail gel?
   Yes, but it is much faster than standard lamps. Adjust your exposure times accordingly.
5. How do I mount this to a heat sink?
   Use high-quality thermal conductive glue or solder the bottom "slug" to a metal-core PCB (MCPCB).
6. Is this LED waterproof?
   No, the SMD bead is not waterproof. It must be housed in an enclosure for outdoor use.
7. Can I use a standard 220V LED driver?
   Only if it is rated for 700mA constant current and the voltage range includes 3.4V-3.8V.
8. What happens if I under-drive it at 350mA?
   The LED will run cooler and last longer, but the UV output will be roughly half.
9. Does 365nm light kill bacteria?
   It has some germicidal effect, but UVC (254nm) is more effective for sterilization. 365nm is primarily for curing and fluorescence.
10. Can this detect pet urine stains?
    Yes, 365nm is the "gold standard" for forensic fluid detection and will show stains much more clearly than 395nm.
11. What is the lifespan of this LED?
    With proper cooling (keeping junction temp <80°C), it can last up to 50,000 hours.
12. What resistor do I need for a 5V supply?
    A 2.2 Ohm (2W or higher) resistor is typical, but a constant current driver is highly preferred.
13. Is the beam focused?
    It has a wide 120-degree spread. For a spot-beam, you will need a 20mm LED lens/collimator.
14. Can I use this for PCB photo-etching?
    Yes, it is excellent for exposing dry-film photoresist and UV-curable solder masks.
15. What is the difference between 365nm and 370nm?
    They are virtually identical in application. This LED covers that specific narrow band.
16. Will this fade my furniture or plastics?
    Prolonged exposure to high-power UV will eventually cause "photo-bleaching" or degradation of some plastics.
17. Can I dim this LED?
    Yes, but only via PWM (Pulse Width Modulation) through a compatible LED driver.
18. Why is this LED more expensive than white 3W LEDs?
    UV-emitting dies require more complex semiconductor manufacturing and specialized packaging materials.
19. Does it come with the star PCB?
    This listing is for the SMD Bead only unless otherwise specified in your selection.
20. Is this safe to use on skin?
    Avoid skin exposure. High-power UVA can cause skin damage and "sunburn" effects with prolonged contact.