FAQs
Featured FAQ
Expert Analysis of UV LED Applications, Mastering Key Selection of COB LED,
SMD LED, and Power LED Solutions
Violumas-Specific Questions
1
What kind of optics does Violumas provide?
Violumas provides a multitude of lens options for UV LEDs depending on the wavelength. We can provide UV LEDs with 15°, 30°, 60°, 90°, 120°, or 135° flat panel optics.
We can also remove the lens completely to maintain the naturally wide angle of the LED chip if that is preferred.
2
What makes 3-PAD LEDs special?
3-PAD LEDs are exclusively manufactured by Violumas and designed with an additional thermal pad, which is an electrically-isolated structure for efficient heat extraction. The thermal pad rapidly conducts heat from the chip’s junction to the heat sink via a copper pillar mesa structure on our specialized Pillar MCPCBs.
The combination of 3-PAD LEDs on Pillar MCPCBs allows for extremely low thermal resistance and rapid heat dissipation.
Learn more about the advantages of 3-PAD technology
Are you able to provide UV LEDs with specific wavelength constraints?
Yes, we are able to accommodate specific wavelength constraints for the UV LEDs. We can select specific wavelength bins to ensure that all products are between a set wavelength tolerance. The pricing for UV LEDs with specific wavelength constraints may be higher than our standard offerings as the yield for some wavelengths may be low.
4
How do I determine the best UV LED solution for my application?
Our team can help to identify the best UV LED components for your application with consideration of the optical output, beam angle, and mechanical/electrical requirements. In order to determine the optimal UV LED solution, we recommend the use of optical simulations to better understand the expected irradiance and uniformity for various settings. First, a list of target specifications is generated including information such as the exposure area, wavelength, throw distance, irradiance, uniformity, and mechanical and electrical restrictions. Using the target requirements, optical specialists at Violumas can help you determine the best optics and required number of LEDs for the application.
Learn more about custom UV LED solutions：https://www.violumas.com.tw/customized
How do I determine the best UV LED solution for my application?
What kind of power supply do I need for operating UV LEDs?
What kind of power supply do I need for operating UV LEDs?
We recommend operating UV LEDs with constant-current power supplies, which support limited voltage ranges and maintain the set current without over-driving the LEDs. If a constant voltage driver is used instead and the current is not regulated, as the LED temperature increases when powered ON, the LED forward voltage would decrease accordingly which would eventually lead to thermal runaway.
Learn more about selecting an appropriate power supply for your UV LEDs here: https://www.violumas.com.tw/drivers
What kind of power supply do I need for operating UV LEDs?
What kind of cooling solution do I need for operating UV LEDs?
A proper cooling solution such as a heatsink is critical for operating UV LEDs. UV LEDs dissipate heat through the backside, so it is important to have a suitable cooling solution with good thermal dissipation made from materials such as copper or aluminum and to apply thermal interface material between the LED and heatsink. UV LEDs with lower power consumption can be passively cooled through convection with heatsinks. High power UV LEDs with high electrical consumption may require fan-cooled heatsinks.
Finally, liquid cooling is recommended for high power UV LEDs that cannot be cooled with forced convection from fans. Please contact the Violumas team to learn more about designing an appropriate heatsink for your specific application
What kind of cooling solution do I need for operating UV LEDs?
How do I determine the best UV LED solution for my application?
UV irradiation can cause degradation such as yellowing, cracking, and becoming brittle on certain materials.
Materials that will be exposed to UV irradiation should be UV-resistant or tested for repeated exposure to UV irradiation.
What is the effect of UV irradiation on material degradation?
What is the difference between SMD and COB UV LEDs?
Surface Mount Device (SMD) LEDs are commonly available, square packages of LED chips available in compact form factors ranging from 3x3mm to 6x6mm.
SMD UV LEDs need to be mounted to PCBs or MCPCBs to be powered on. A more recent development in LED packaging is the Chip-On-Board (COB) LED, which consist of LED chips directly mounted onto the PCB or MCPCB for improved heat dissipation.
COBs do not require additional MCPCBs and can offer high density, flexible arrangements of LED die.
What is the difference between SMD and COB UV LEDs?