High Brightness LED, HBLED: high power LED

LEDs are now being used for lighting applications – these need high brightness LEDs sometimes also called high power LEDs.

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High brightness LEDs, also known as HBLEDs or high power LEDs, are being used increasingly for lighting applications.

These high power LEDs or high brightness LEDs provide much higher levels of light output than the traditional indicator LEDs. This places new challenges on the technology, although they are able to provide high levels of performance: greater efficiency than other forms of lighting technology and a much longer lifetime.

HBLED: high brightness LED definition

With many LEDs being introduced onto the market, and available light levels increasing, it is useful to be able to define a high brightness HBLED and a high power LED as these terms refer to slightly different aspects of operation.

High brightness LED HBLED definition: One HBLED definition is that it is a light emitting diode that produces over 50 lumens (1 candela = 12.75 lumens).
High power LED: Generally a high power LED is defined as consumes more than 1 watt in power.

Although high power LEDs and high brightness LEDs, HBLEDs may normally be one and the same, the two definitions refer to different characteristics or parameters.

HBLED technology

There are several enhancements that have been made to basic LED technology to enable the high brightness LEDs, HBLEDs to be developed and successfully manufactured.

The initial indicator LEDs used a traditional through hole style wired package. A standard 5mm LED would produce a light output of around two or three lumens for an input of 100 mW - equivalent to 20 or 30 lumens per watt.

Surface mount technology allowed development of LEDs in such a way that the printed circuit board could act as a heat sink - with LEDs mounted onto the board, any heat could be removed reasonably effectively, and this allowed light levels to be increased. With HBLEDs running at much higher power levels, dissipating the increased levels of heat generated is a key issue.

The next development was to add a thermal heat slug directly into the bottom of the surface mount package. Being located directly under the LED junction, this allowed heat to be removed far more effectively.

High brightness LEDs utilise this effective heat removal to enable the HBLED junction to remain within its safe limits while still producing the light output required. In addition to this, more effective manufacturing processes have enabled the efficiency to be improved.

High brightness LED / other technology comparison

High brightness LEDs provide some distinct advantages over many other forms of lamp. A table comparison of HBLEDs with other major technologies is given below.

Lamp type	Typical efficiency (Lumens per watt)
High brightness LED, HBLED	>100 and improving
Tungsten filament lamp	~18
Compact Fluorescent Lamp, CFL	~60
Sodium lamps, e.g. street lamps	~100 - 200

HBLED advantages

High brightness LEDs have a number of advantages over the standard LEDs and other technologies.

Offer higher brightness levels, particularly when compared to standard LEDs
Longer life than other lighting technologies including incandescent and CFLs.
Low cost: HBLEDs although expensive to buy initially, provide a lower cost over the lifetime of the LEDs in view of their longer life.
RoHS manufacturing compatibility (lead free) – they are also far more environmentally friendly than CFLs that require specialist disposal.

In view of their advantages high brightness LEDs, HBLEDs are being used increasingly in many lighting applications from domestic, office and room lighting to automotive lighting.