What Are "COB" LEDs and Why Do They Matter?

What are Chip-on-Board (“COB”) LEDs?

Chip-on-Board or "COB" refers to the mounting of a bare LED chip in direct contact with a substrate (such as silicon carbide or sapphire) to produce LED arrays. COB LEDs have a number of advantages over older LED technologies, such as Surface Mounted Device ("SMD") LEDs or Dual In-line Package ("DIP") LEDs. Most notably, COB technology allows for a much higher packing density of the LED array, or what light engineers refer to as improved "lumen density". For example, using COB LED technology on a 10mm x 10mm square array results in 38 times more LEDs compared to DIP LED technology and 8.5 times more LEDs compared to SMD LED technology (see diagram below). This results in higher intensity and greater uniformity of light. Alternatively, using COB LED technology can greatly reduce the footprint and energy consumption of the LED array while keeping light output constant. For example, a 500 lumen COB LED array can be many times smaller and consume substantially less energy than a 500 lumen SMD or DIP LED Array.

 

 

The other big advantage of using COB LED technology lies in the fact that COB devices have only 1 circuit and 2 contacts for the entire chip regardless of the number of diodes. This single circuit design, regardless of the number of diodes on the chip, leads to simplicity for the rest of LED device.

 

The advantages of Chip-on-Board LED arrays include:

• Compactness due to the small size of chip
• High-Intensity, particularly at close distances
• High-Uniformity, even at close working distances
• Design Simplicity because only 1 circuit and 2 contacts are required
• Superior Thermal Performance for increased life, stability and reliability

 

Why are COB LEDs so important when running on battery power?

When designing a battery-powered lighting system, there has always been a trade-off between the amount of high-quality lumen output (i.e. brightness) and length of runtime via battery operation. Historically, the more high-quality brightness desired, the shorter the runtime (assuming you are using the same size battery). However, with the recent development of COB LED technology, this tradeoff has become much less of an issue. For the first time, very low wattage COB LEDs can output extremely high-quality, ultra-bright light. As a result, a relatively small and lightweight lithium-ion battery pack can power a COB LED based light system for very long periods of time. In fact, our 6W COB LED Trade Show Light will run 14-15 hours using our very small and light weight (1.25lbs) rechargeable Mobile Power Center. High quality light output over extended periods of time using a relatively small battery was simply not possible just a few short years ago! This is why COB based LED lights were the only real choice we had when designing our ultra-bright, ultra-efficient light systems. As such, Silicon Lightworks exclusively uses COB LED technology in its full line of trade show exhibit lighting.

 

In summary, chip-on-board LEDs are the latest and most advanced technology on the market today. Simply put, COB LEDs are brighter, consume less power, and output a higher quality beam of light compared to older LED technologies found in most other trade show lighting today. The next time you are in the market for exhibit lighting, insist on COB LED technology!