A modern high power LED can produce nearly one-hundred lumens per LED light, while dissipating well under five watts. Even more attracting than than energy efficiently, is their cost efficiently. In the past, a custom LED lighting design might have required between thirty to fifty individual light emitting diodes just to equal the luminous output of a single high brightness LED. In materials alone, this would cost at the very least, between two to three times that of our single high output LED. In addition, this calculation does not even account for assembly costs. On occasion, through-hole component assembly can be as expensive as the light emitting diode itself. For this reason, the cost efficiency for a single high power LED emitter can be as much as ten times more cost efficient when compared to an older technology. However, several new challenges accompany the benefits offered by the high power LED. Among these challenges include the requirements for more precise thermal and power management.
Modern LED lighting technology has LED to recent advances in material manufacturing that permit higher junction temperatures and increased luminous outputs. These advances have opened up a new market for the high brightness LED and many light emitting diode equipped devices. We can refer to the term "high power LED" as any light emitting diode requiring special attention to thermal and power management. High output LED packages utilize surface mount technology, as opposed to older devices that relied on through-pins for circuit board mounting. Advantages of the high power LED include increased cost efficiency and luminous output.
The primary advantage with the high power LED is light output. Most devices one watt or greater can produce a significantly greater amount of total light when compared with many smaller light emitting diodes. This is advantageous in many custom LED lighting designs for two primary reasons. The first is cost efficiency. The high power LED tends to produce more light for less money. A common mistake while calculating for lumens per dollar is to overlook assembly costs. A single high output LED will cost ten times less to assemble than ten smaller light emitting diode with a combined luminous equivalency. The second advantage is space efficiency. Many custom LED lighting designs require as much light as possible, but are limited as far as component space availability. In addition, it only makes sense to consume as little board space as possible unless an application requires some type of specific spacing or layout.
A major disadvantage with the high brightness LED is its tremendous heat dissipation. Special attention to thermal management is usually required to ensure a reliable and successful design. Design and material costs are scientifically higher due to the extra time, testing, and parts that must accompany the high power LED. The process of heat dissipation can generally be broken down into three sub-categories. The first involves the transportation of thermal energy away from the light emitting diode junction. An integrated heat slug allows heat to conduct away from the die and into a set of thermal vias or metal-cored circuit board. This heat now requires an external heat sink as a means of absorbing the intense thermal energy. The final stage of dissipation allows this energy to dissipate into the surrounding environment. This is primary accomplished by either natural or forced air convection. Forced air convection typically involves an electric fan responsible for cooling the heat sink.
One of the most complicated factors associated with the high output LED is cost. Initial design costs are expectedly higher than with traditional LED lighting systems. This is most due to the extra attention required with thermal management and LED drive circuitry. A greater number of mathematical calculations as well as advanced tests are typically required to ensure proper operation. In addition to this extra time and effort required during development, increased production costs due to requirements for more complex LED drive circuitry and thermal devices greatly affect one's budget. Although design and production costs associated with high power LEDs are significantly higher, the technical advantages and cost efficiency often offset investment costs in many modern lighting applications. Overall, cost efficiency usually outweighs that of traditional high brightness LED lighting systems. This is simply because the high power LED tends to offer a dramatically higher value of lumens per dollar.