3W SMD High Power UV LED Bead - 380nm to 385nm Purple Ultraviolet UVA Emitter

Specifications:

• Wavelength: 380nm - 385nm (UVA Spectrum)
  
• Power Dissipation: 3 Watts
  
• Forward Voltage (VF): 3.2V – 4.0V DC (Typical 3.6V)
  
• Forward Current (IF): 700mA (Recommended) 
  
• Radiant Power (Radiometric Flux): 700mW – 1200mW
  
• Viewing Angle: 125° (Lambertian Pattern)
  
• Operating Temperature: -40°C to +85°C

Key Applications & Projects

• dvanced UV Curing: Ideal for UV-curable inks, coatings, and adhesives that require a balance of surface and deep-layer penetration.
• Authentication & Anti-Counterfeiting: Detects high-level security threads in currency and legal documents that may not respond to longer 400nm wavelengths.
• Specialized Horticulture: Used in controlled environments to trigger specific secondary metabolite production in plants (UV stress response).
• Forensic & NDT Inspection: Used for non-destructive testing to find micro-fissures in metal components using fluorescent dyes.
• Medical & Dental Research: Suitable for teeth whitening setups and medical-grade sterilization research.

Project Evolution 

• Past Projects (Prerequisites): If you have used standard 395nm "Blacklight" strips and found they weren't strong enough for professional curing, this 3W bead is the logical upgrade.
• Feature Upgrade: This emitter provides higher optical density than common LEDs. It allows for "Flash Curing"—reducing cure times from minutes to seconds in industrial setups.
• Effort/Requirements: Advanced. Requires SMD soldering skills and a dedicated constant current driver. Heat management is non-negotiable.

Virtual Technician & Wiring

• ⚠️ SAFETY FIRST: Even though 385nm is near the visible range, it carries high energy. Avoid skin exposure and always wear UV-protective eyewear.

• Thermal Management: This LED produces significant heat in a tiny 3.5mm footprint. It MUST be soldered to an MCPCB (Metal Core PCB) and attached to a larger aluminum heat sink.

Wiring Guide:

• Positive (+): Connect to the Anode.
• Negative (-): Connect to the Cathode.
• Driver: Use a 700mA Constant Current Buck/Boost converter. Avoid using simple resistors for 3W power levels as they will become dangerously hot.

​Packages include:

1 X 3W SMD High Power UV LED Bead - 380nm to 385nm Purple Ultraviolet UVA Emitter

Frequently Asked Questions (FAQ)

1. How is 380nm different from 395nm?
   380nm has higher energy and is less visible to the eye. It is better for industrial curing where "visible purple light leakage" needs to be minimized.
   
2. Can I run this at 1000mA?
   Yes, but only with a high-performance heat sink. We recommend 700mA for a balance of brightness and longevity.
   
3. What color does the light look like?
   It appears as a very deep, saturated violet/purple, but it will look "dimmer" than a 405nm LED because it's further from the human eye's peak sensitivity.
   
4. Is this LED compatible with standard 20mm star PCBs?
   Yes, provided the star PCB has a 3535 or "Cree-style" soldering footprint.
   
5. Does this work for UV 3D printing resin?
   Yes, most 405nm resins will cure significantly faster with this 385nm light.
   
6. Will this kill germs?
   It has mild germicidal properties, but it is a UVA LED. For true sterilization, you should look for UVC (254nm-275nm) LEDs.
   
7. What is the lifespan?
   With junction temperatures kept below 90°C, this chip is rated for up to 50,000 hours.
   
8. Can I use a 12V power supply?
   Only if you use a Constant Current LED Driver. Connecting 12V directly will instantly destroy the LED.
   
9. Is a resistor enough for a 5V supply?
   A 2.2 Ohm, 5W resistor would work, but it is inefficient. A switching driver is highly recommended.
   
10. Does it emit heat?
    Yes, about 70-80% of the energy consumed is converted to heat. Good thermal bonding is critical.
    
11. Can this detect scorpions?
    Yes, scorpions fluoresce brilliantly under the 380-385nm range.
    
12. Is it dimmable?
    Yes, via PWM (Pulse Width Modulation) on the driver side.
    
13. Can I use this for PCB exposure?
    Yes, it is excellent for exposing UV-sensitive dry film and solder mask.
    
14. Is the lens glass or plastic?
    Most high-quality 385nm LEDs use a quartz or high-temp silicone lens to prevent yellowing from UV exposure.
    
15. Does it come with the star PCB?
    No, this is the discrete SMD component.
    
16. Why is it called "UVA"?
    Ultraviolet A (315-400nm) is the long-wave UV band used for curing and blacklights.
    
17. Can I solder this with a regular iron?
    It is difficult. Reflow soldering or a hot plate is recommended for 3535 SMD components to ensure the thermal pad is correctly bonded.
    
18. Will it fade my carpet?
    Yes, prolonged exposure to high-power UV will cause colors to fade over time.
    
19. What is the viewing angle?
    125 degrees, providing a broad, even coverage.
    
20. Is it safe to use for a DIY party light?
    It is much more powerful than a party light. It should be used with caution and never pointed directly at people's faces.