FAQs

Chip-on-Board (COB) LED packaging refers to placing the LED die directly on a PCB substrate where it is fixed by silvered epoxy or solder. The intended circuit is then completed with wire bonds between the LED chips and the PCB. Generally, an encapsulation, hard of soft, is used to protect the wire bonds and LEDs. As the LED chip is the smallest light building block available, the light engine itself can be a highly customized, application specific device with many LEDs with almost any spacing or array dimension. Multiple colors and driving circuits can be designed. Optics can be mounted directly to the PCB. The electronics if desired can be on or off the PCB (or light). The LED chips ranging in size generally from ~300 microns to 1-mm per side can be considered Lambertian emitters and have no integrated optics like common through-hole or surface mount devices. This allows the optical performance to be customized for the application starting with the most basic element. The chips are directly mounted to PCB substrate so the heat is removed from the LED more efficiently than through several intermediate junctions in a surface mount LED or through the leads in a through-hole LED package. In short Chip-on-Board is ideal for the highest performance or highly constrained applications.

LEDs are available in many wavelengths from 250 nm in the UV to several microns in the IR. In some parts of the visible spectrum an LED with a peak wavelength may be available every 5-10nm. However in some parts of the spectrum there are no LEDs available due to technology limitations.

Not exactly but It might be possible to provide enough optical power for your application at specific wavelength ranges. White LEDs do not replicate the spectrum of legacy lighting technologies but can appear very similar to the human eye.

Unfortunately we cannot. LEDs can only be ordered from our suppliers in bins of peak wavelength and optical power. The peak wavelength range of these bins are generally +/-5 or +/-10 nm wide. To get narrower bins is sometimes possible. However, to get a narrower peak wavelength range requires further sorting from larger lot of LEDs purchased. Ultimately, it would be very difficult to control the wavelength to within a single nanometer due to fluctuations with current and temperature. If those are tightly controlled it may be possible.

MTBF is not generally used in the LED industry because LEDs when used properly, that is with good heat sinking and without excessive current, don’t generally catastrophically fail. Their light output will gradually decrease from the initial maximum. LED lifetime is generally defined by the time it takes for the maximum optical power to decrease to 70% of its original. This is termed “L70” by the larger LED industry.

We rely on the specification of the LEDs run at rated current by our vendors to estimate lifetime. The lifetime will be at least 50,000 hours and could be 100,000. Our lights feature better thermal management than is typically assumed so even when run continuously at higher currents we expect to achieve 50,000 hours at minimum. Strobing or intermittent operation generally increases the effective lifetime because heat is not built up and the light is off more often than on. MTBFs will be 100,000 hours or more.

While many high brightness LEDs available from major manufacturers are described as products as 1W, 3W, or 5W devices this is not a good description of how an LED light will perform, just as it is not a good description of how a fluorescent or halogen light will perform. This is a description of the electrical power draw, only a fraction of which is converted to optical power and a fraction of that reaches where it is needed.

We specify our products or try to define specifications for custom designs in Watts per square meter (W/m2) as projected over a given area at specific distance from the source. That being said our lights or designs produce under a Watt of optical power to several 100 Watts of optical power. Direct comparison with legacy lighting technologies is difficult and requires very controlled testing. However, our customers have confirmed we make lights that can be brighter than halogen and other lighting technologies.

Yes, all of our lights can be configured for constant current control. The COBRA product family features an integrated light specific current controller. The SpecBright products can all be configured as constant current controlled lights for no extra cost as standard. While this requires an extra part in addition to the power supply–a current controller such as our CMP-M-400 controller, a CMS strobe controller, or your own controller—the benefits are potentially higher brightness, more linear intensity control, overdriving potential, less heat generated, and better stability.

If you are running the light at or near full power for a few minutes or longer you need heat sinking. The body of the light must be kept below 45 degrees Celsius. If you attach our heat sink accessory you can be assured that for normal factory environments the light will be within safe operating limits. Your own fixturing may also be just as good. We made the heat sinks modular to allow you the flexibility when integrating our lights into your system.

Our systems can be utilized for sterilization but the lamps effectiveness is largely dependent on the environmental conditions in which they are operating and how it is designed. ProPhotonix has more than 25 years of experience partnering with OEMs to develop innovative, reliable LED systems tailored to their specific application needs. We work closely with our partners to understand their application requirements and our multidisciplinary team of LED experts designs and manufactures high-performance LED solutions optimized for their application. Our aim is to deliver a competitive advantage for our customers.

Yes. UVC LED systems can be designed to treat a room. ProPhotonix has more than 25 years of experience partnering with OEMs to develop innovative, reliable LED systems tailored to their specific application needs. We work closely with our partners to understand their application requirements and our multidisciplinary team of LED experts designs and manufactures high-performance LED solutions optimized for their application. Our aim is to deliver a competitive advantage for our customers. 

Ref. https://www.lightbulbs.com/blog/how-led-lights-are-making-hotels-cleaner

Ref. Lawal, O., Pagan, J. Hansen, M. 2017. When Will UV-C LEDs be Suit-able for Municipal Treatment? Conference Presentation. IUVA World Congress. 18 September 2017.

UV-C LEDs are a relatively new technology. As can be seen from the chart above, UVC LED efficiency low, below 10%. However, UVC LED development is following a similar rapid improvement profile that has occurred for other LED technologies such as red, blue and UV-A wavelengths.

Low efficiency also means that the lifetime of these LEDs is less than more mature LED technology. However, for some wavelengths, 10,000 hrs have been reported.

As applications are still being developed and LED manufacturers improve their processes, LED unit costs continue to reduce. However, the pricing is still not at the level of more mature LED wavelengths and commercially viable applications are limited for the next 3-5 years. As a result of the COVID-19 pandemic, there has been increased interest in UV-C LEDs which may increase this timeline.

Wavelength, Irradiance and time are the most important factors. 

Wavelength: UVC wavelength range is between 100nm to 300nm.  Generally, UV-C germicidal wavelength at 265nm is the most effective to kill harmful microorganisms via molecular lesions of DNA and RNA in the air, water and on surfaces as this is the absorption peak of DNA and RNA. Disinfection can occur more efficiently at different wavelengths via different disinfection mechanisms such as cell wall degradation which will cause death. Sometimes the optimum peak wavelength may not be the best choice of wavelength. If an alternative LED wavelength delivers higher intensity and dose at a more efficient cost, it may be a better choice that the “optimum wavelength”.

Irradiance is a measure of how much UV energy falls on a particular surface point. Importantly, it is not the same as how strong a particular UV lamp is. A 10W lamp that emits UV in all directions, for example, may provide lower UV irradiance at a particular spot than a 5W lamp that focuses its UV output in a narrow beam.

Time: The effective UV energy density, or dose, is the amount of UV energy that falls on a surface for a particular time. It refers to the necessary UV energy required for micro-organisms (bacteria, viruses, algae in suspension…) to absorb to the point of being neutered or killed.

Mercury based UV lamps have a filling composed of mercury and a starting gas usually Argon. There are two major types differentiated by the mercury vapor pressure in the lamp. Low-pressure lamps emit at a wavelength of 253.7nm. High pressure lamps radiate a broad-band UVC radiation, rather than a single bandwidth. The issue with UVC Mercury lamps is their size, toxic mercury usage, and need for chlorine to enable effective disinfection.

Excimer lamps produce UV light by spontaneous emission of Excimer molecules. Excimer lamps are mercury-free, instant on lamps which generate low levels of heat in comparison to mercury lamps. However, Excimer lamps have a low UVC efficiency and high cost. 

No, in fact UV can be beneficial to food processing, production and help with maintaining freshness. Fresh food products are often processed using UV light to reduce the microbial load. Water has been treated with UV light to obtain drinking water for quite some time.

Ref. Hinds LM, O’Donnell CP, Akhter M, Tiwari BK. Principles and mechanisms of ultraviolet light emitting diode technology for food industry applications. Innov Food Sci Emerg Technol. 2019;56(January):102153. doi:10.1016/j.ifset.2019.04.006

A wavelength of 265nm is considered the optimum as it is the peak of the DNA absorption curve. UVC has been shown to be effective in the disinfection of water, air, and surfaces on various pathogens such as E. coli, L. innocua, and COVID-19. However, disinfection and sterilisation occur over a range of wavelengths and in certain applications alternative wavelengths should not be dismissed. UVC LEDs can be manufactured to target very specific and narrow wavelengths. This allows solutions to be tailored to the particular application need. 

Inside the semiconductor material of the LED, the electrons and holes are contained within energy bands. The separation of the bands determines the energy of the photons (light particles) that are emitted by the LED. The photon energy determines the wavelength of the emitted light, and hence its color. Different semiconductor materials with different bandgaps produce different colors of light. One the advantages of LEDs over Hg lamps is the precise wavelength (color) can be tuned by altering the composition of the light-emitting, or active, region. 

UVC lamps have been used for many decades to sanitize water, air and surfaces. However, precautions must be taken with this technology. Working unprotected for even a few minutes can cause injury.

UVC light is invisible to the human eye so during operation the light can be mistaken for being benign causing eye damage. As negligible heat is produced by UVC LEDs the user may not realize the danger until after the exposure has caused damage to the skin. Symptoms typically occur 4 to 24 hours after exposure. More serious effects of UVC include accelerated skin aging and skin cancer. 

Traditional UVC lamps shorter than 250nm produce ozone which is emitted into the environment and needs to have appropriate infrastructure to remove. Some UVC lamps are made using mercury so safe disposal is essential. UVC LEDs do not emit ozone or contain mercury. 

220nm LEDs are not commercially available right now. UV-C LEDs are a relatively new technology. The lowest wavelength available to buy is 255nm.  However, UVC LED technology is rapidly developing and overtime new wavelengths will be developed, costs will reduce and efficiencies will increase as has already happened within the visible, infrared, violet and UVA and B wavelength LED ranges. 

A UVC light-emitting diode (LED) works like any other LED. It is a semiconductor device that emits light when an electric current is passed through it. Light is produced when the particles that carry the current (known as electrons and holes) combine together within the semiconductor material. Since light is generated within the solid semiconductor material, LEDs are described as solid-state devices. It distinguishes LEDs from other sources that use heated filaments (incandescent and tungsten halogen lamps) or gas discharge (mercury lamps).

The UVC wavelength band is defined as being in the range 200-280nm. Currently LEDs are commercially available between 255nm to 280nm.

UV LED curing systems are now the technology of choice across a wide range of applications including:

• Printing
• Industrial Printing
• Digital Printing
• 3D Printing
• Coatings Applications
• Adhesives

Laser diodes are used in a broad range of applications including:

• Medical, biomedical and dental equipment for surgery, patient alignment, sample analysis and image capture
• Robotics and gesture recognition for factory and warehouse automation, autonomous vehicles, gaming and eye tracking
• Alignment and targeting in industrial, security and defence applications
• Measurement and 3D imaging for the construction industry, surveying, quality assurance in manufacturing, and profilometry
• Materials sorting applications in agriculture, food processing and waste sorting
• Laser shows and laser displays for the entertainment and advertising industries
• Laboratory analysis and smoke detection systems using particle measurement and spectroscopy

For more information on Laser Diodes, see our laser diodes blog posts.

ProPhotonix offers a wide variety of wavelengths from 405nm to 1500nm with a maximum output power up to 2W.

Our digital laser modules  offer more control over operational commands if your application requires it e.g output power and pulse conditions. Our digital interface is a simple and user-friendly way of controlling and monitoring the performance of your laser module.

The process starts with your requirements. Our engineers will collaborate with your engineering team to decide on the exact specifications required. Next, we develop a prototype with our in-house specialists and leverage their optics, electronics, thermal, software and mechanical expertise. We work through feedback you may have on the prototype and move onto the production stage. The process is highly collaborative from end to end. We like to think of it as an integrated partnership that is ongoing, and doesn’t come to an end once the product is delivered. We will work with you to ensure optimal performance throughout the life of the product.