3W SMD High Power UV LED Bead - 405nm to 410nm Near-UV Purple Emitter

Specifications:

• Wavelength: 405nm - 410nm (Near-UV / Violet Spectrum)
• Power Dissipation: 3 Watts
• Forward Voltage (VF): 3.2V – 3.6V DC
• Forward Current (IF): 700mA (Constant Current Mandatory)
• Radiant Flux: 800mW – 1100mW
• Viewing Angle: 120° (Lambertian Pattern)
• Operating Temperature: -40°C to +85°C (Requires active cooling)

Key Applications & Projects

• 3D Printing (SLA/DLP/LCD): Perfect for building or repairing UV curing chambers and printer light engines.
• PCB Manufacturing: High-speed exposure of dry-film photoresist and UV-curable solder masks.
• Dental R&D: Prototyping dental curing lights for composite resin hardening.
• Industrial Photocatalysis: Used in chemical research for light-triggered reactions.
• Fluorescence Analysis: Identifying specific minerals and chemical markers that react only to the 405nm spectrum.

Project Evolution 

• Past Projects (Prerequisites): If you’ve worked with 395nm blacklights and found the cure depth insufficient for thick resins, this is the precision upgrade you need.
• Feature Upgrade: Transitioning to 405nm unlocks compatibility with the widest range of standard industrial UV resins. It offers a deeper surface-cure than 365nm while maintaining higher energy than 420nm.
• Effort/Requirements: Intermediate. You will need a constant current LED driver (700mA) and an aluminum heat sink (Star PCB) for safe operation.

Virtual Technician & Wiring

• ⚠️ CRITICAL SAFETY: This LED emits high-intensity near-UV light. Never look directly at the emitter while powered. Use UV-rated safety goggles.

• Thermal Management: This 3W chip generates localized heat extremely quickly. It MUST be soldered to an MCPCB (Metal Core PCB) or Star Heat Sink before use. Running for more than 5 seconds without a heat sink will cause permanent damage.

Wiring Guide:

• Anode (+): Connect to the Positive terminal of a 700mA Constant Current Driver.
• Cathode (-): Connect to the Negative terminal of the driver.
• Note: For multi-LED arrays (like in 3D printers), wire them in series to ensure uniform current distribution across all chips.

​Packages include:

1 X 3W SMD High Power UV LED Bead - 405nm to 410nm Near-UV Purple Emitter

Frequently Asked Questions (FAQ)

1. Why use 405nm instead of 395nm?
   Most 3D printing resins are optimized for 405nm. Using 395nm may lead to slower cure times or tacky surfaces.
2. Can I use this for a nail lamp?
   Yes, it is highly effective for curing UV/LED nail gels, but it is much more powerful than consumer-grade bulbs.
3. Does it look bright purple?
   Yes, 405nm is on the edge of the visible spectrum. It will look like a very bright, saturated violet light.
4. Is it safe to touch the lens?
   Avoid touching the silicone lens with bare hands. Oils from your skin can burn into the lens at high temperatures, reducing efficiency.
5. How many of these do I need for a curing box?
   For a standard 3D print curing chamber, 4 to 6 of these LEDs provide excellent coverage.
6. Can I use a resistor for power?
   While possible with a high-wattage resistor, a Constant Current Driver is much safer for 3W high-power LEDs.
7. Is this LED waterproof?
   No, it is a discrete SMD component and must be protected from moisture.
8. What is the lifespan of this LED?
   With proper cooling (keeping the base <60°C), it can last up to 50,000 hours.
9. Can I use this for plant growth?
   UV light in small doses can trigger certain plant responses, but this is not a primary growth light.
10. Will this work with a 5V power supply?
    Yes, if paired with a buck-converter LED driver that outputs 700mA.
11. Is the wavelength exactly 405nm?
    It covers a narrow band between 405nm and 410nm.
12. Can I dim this LED?
    Yes, dimming is possible via PWM through a compatible LED driver.
13. Is the beam focused?
    It has a wide 120-degree angle. Use a 20mm LED lens if you need a focused spot beam.
14. Why is it more expensive than white LEDs?
    UV-emitting dies use more specialized semiconductor materials like InGaN on ceramic substrates.
15. Does it come with the aluminum star?
    This SKU is for the SMD Bead only. Please purchase the Star PCB separately if needed.
16. Is it safe to use on skin?
    Avoid skin exposure. High-power UVA can cause skin damage with prolonged contact.
17. Can this detect pet urine?
    Yes, but 365nm or 395nm are usually more effective for forensic detection than 405nm.
18. What solder should I use?
    Standard lead-free or leaded solder works. Reflow soldering is recommended for the thermal pad.
19. How much current does it draw?
    700mA is the nominal operating current.
20. Can I use this for indoor lighting?
    No, this is a specialized industrial LED and should not be used for general illumination.