COB (Chip on Board) LEDs are compact LED modules with a bright light output. They consist of a small square or circular substrate which houses multiple LED chips/dies. These are covered with a phosphor coating. The most common colour of COB LED is white, however there a few more colours available as the technology develops.

How do they work?

COB LEDs have a base substrate, made of aluminium or ceramic, on which the LED dies are mounted. The actual LEDs provide a blue light. The number of LED dies and their typical luminous flux determines the "brightness" of the COB LED.

The layer of phosphor, which is an orangey-yellow colour, sits on top of the LED dies. The phosphor converts the blue LED dies into a white light. The type of phosphor creates different colour temperatures.

What is colour temperature?

Colour temperature describes the warmth or coolness of the LED light output. "Warm" COB LEDs offer a yellow-orange light output while "Cool" COB LEDs tend to be a bluer white. Colour temperature is measured in Kelvins with the symbol "K".

What are the advantages of COB LEDs?

• Higher LED density than traditional LED mounting process

• No need for multiple soldering - just one package

• Bright light output

Uses for COB LEDs:

• General purpose lighting

• Downlights

• High Bay lighting

• Low Bay lighting

• Spotlights

• Solid State Lighting (SSL) replacements