The Components of LEDs and How They Work

LED’s (Light Emitting Diodes) have become more popular over time due to their long-life and durability. They are very energy efficient and ecologically friendly which is why many people swap to LED from a traditional filament lamp.

You probably know about LED’s, but do you know how many components are used to create an LED or how they operate?

This week, we take a look at each component in detail as well as how they function:

LED Components


Epoxy Lens/Case – The epoxy lens has three major functions. First, it is designed to allow most of the light to escape from the semiconductor. Second, it focuses the light (view angle) and lastly, it protects the LED semiconductor from outside elements. The epoxy totally embeds the entire unit which makes the LED virtually indestructible. There are no loose or moving parts within the solid epoxy enclosure. Non-diffused lenses that do not have glass particles in the epoxy produce a narrow viewing angle of +/-12 degrees from the centre.

Wire Bond – The wire bond is typically an interconnection between the anode (positive side) and the cathode (negative side).

Reflective Cavity – Light extraction in LEDs is one of the most its important aspect. The reflective cavity’s purpose is to make the LED’s light be brighter by focusing its light into a single point.

Semiconductor Die – It is a small block of semiconducting material, on which a given functional circuit is fabricated. It is the heart of any electronic products and contains a lot of integrated circuits and full of intelligence associated with it.

Anvil and Post – There are two leads of an LED that are used to supply input voltage. The longer lead is positive and known as Post, and the smaller is negative known as Anvil. So basically, the anvil and the post determines the polarity of the two the leads. The Anvil is also used to physically hold the chip, provide some heat-sinking, and provide some directivity to the emitted light.

How LEDs Work

Unlike the incandescent lamp that gets it light by heating the tungsten filament through passing an electric current in it for it to glow with visible light, LEDs get their light through a phenomenon called electroluminescence. Electroluminescence is a phenomenon wherein a material emanates a light when an electrical current is passed through it. This happens when electrons are sent through and fill the electron holes. An electron hole exists where an atom lacks electrons and therefore has a positive charge. Semiconductor materials like germanium or silicon are among those materials that can be “doped” to create and control the number of electron holes. Doping is the adding of other elements to the semiconductor material to change its properties. By doping a semiconductor, you can make two separate types of semiconductors in the same crystal and the boundary between the two types is called a p-n junction. A p-n junction only allows the current to pass through it in one way or direction, which is why they are used as diodes. As electrons pass through one crystal to the other they fill electron holes and they emit photons or what we call “light”.

Thanks to the advance technology now, we can have a better understanding on how these tiny little things can generate very bright lights. Through LEDs, we can say somehow that the saying “everything happens for a reason” is true.

Using LED’s for a light source is a more reliable and more beneficial option. LED lighting provides you with energy savings, a longer life span and provide years of maintenance free operation.

D.G. Controls offer a wide range of LED beacons used on a variety of applications, from flashing, static, rotating, multi-function – we can help with your needs! Give us a call on 01283 550850!