General Info

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An LED is a semiconductor light source. LEDs are used as indicator lamps in many devices, and are increasingly used for lighting. Introduced as a practical electronic component in 1962, early LEDs emitted low-intensity red light, but modern versions are available across the visible, ultraviolet and infrared wavelengths, with very high brightness.

 

When a light-emitting diode is forward biased (switched on), electrons are able to recombine with electron holes within the device,releasing energy in the form of photons. This effect is called electroluminescence and the color of the light (corresponding to the energy of the photon) is determined by the energy gap of the semiconductor. An LED is often small in area (less than 1 mm2), and integrated optical components may be used to shape its radiation pattern.

 

LEDs present many advantages over incandescent light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster switching, and greater durability and reliability. LEDs powerful enough for room lighting are relatively expensive and require more precise current and heat management than compact fluorescent lamp sources of comparable output.

 

Light-emitting diodes are used in applications as diverse as replacements for aviation lighting, automotive lighting (particularly brake lamps, turn signals and indicators) as well as in traffic signals. The compact size, the possibility of narrow bandwidth, switching speed, and extreme reliability of LEDs has allowed new text and video displays and sensors to be developed, while their high switching rates are also useful in advanced communications technology. Infrared LEDs are also used in the remote control units of many commercial products including televisions, DVD players, and other domestic appliances.

There are basically 3 LED configurations:

  • THT LEDs in cylindrical packages
  • SMD LEDs (Surface Mounted Device)
  • COB LEDs (Chip On Board)

 

THT LEDs in cylindrical packages represent the original configuration of the LED technology. The internally mounted LED chip is encapsulated by a plastic plug, which protects it from outside influences during the manufacturing process (Through Hole Technology THT) and during operation.

 

 

SMD LEDs are individual standard products whose surfaces can be soldered, which like LEDs in cylindrical packages are already enclosed by a housing.

 

 

COB LEDs has the greatest power densities in the smallest space and are often the basis for unique selling points of various products on the market. These criteria can be realized by the COB technology (Chip On Board). Direct contacting of the semiconductors (LEDs) on PCBs allows for optimal thermal management, high packaging density and thus long-lasting and high-performance COB LED modules.

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