Conserving valuable circuit board space does not only reduce manufacturing costs, but also provides a more compact design scheme. Many high intensity LED lighting designs rely on a reduced physical size as an invaluable marketing aspect. Although many LED lights are extremely small, special design tactics can further reduce the overall physical size of a high intensity LED array. Strategic component selection, component placement, and circuit architecture include a few critical aspects of space conservation. The result yields custom LED lighting products with a superior advantage over the competition. The subsequent context describes in detail how achieving each aspect of space conservation becomes possible as well as the benefits gained from each. Taking full advantage of space conservation techniques promotes a more successful overall lighting design.
Traditional through-hole components often feature increased overall dimensions. They also consume value circuit board space, as the wire leads must pass through to the rear side of the circuit board. When overall size becomes critical, traditional through-hole parts may not be feasible. Space conservation techniques restrict physical parameters to a minimal overall thickness. Most modern high intensity LED lamps incorporate slim line surface mount packages, with a minimized footprint. Even though some surface mount LEDs are physically large, they continue to offer space conservation on the bottom layer of the printed circuit board. When this is not enough, high-density component placement and population can provide further space conservation. High-density design incorporate electronic components placed in very close proximity to each other. Therefore, circuit board routing of traces can become extremely difficult. As a result, a multi-layered circuit board is usually required. Some high-density designs will contain as many as twelve circuit layers, or more.
One of the most important steps associated with any new design is strategic component selection. Good high intensity LED selection requires consideration on many levels including electrical, optical, and physical characteristics. Many surface mount LEDs consume much less space than traditional though-hole light emitting diodes. In addition, the SMT LED does not interfere with other electronic components located on the bottom circuit board layer. Through-hole light emitting diode components require space on the top and bottom circuit board layers. In order to conserve as much space as possible, it is often a good idea to select an LED light capable of providing the highest luminous output in as least space as possible. In some cases, a single high power LED lamp can replace an array of smaller light emitting diodes without sacrificing luminous output. The total board space occupied by the single high intensity LED is often much less than that occupied by the array of smaller LED lights. Engineers will consider many additional aspects during component selection in order to implement space conservation.
The orientation and location of specific components can affect a design significantly. LEDs or other components placed next to each other often require special attention to orientation to preserve board space occupied by traces electrically interconnecting the components. Consider a two-layered printed circuit board with a twelve-inch length and only a half inch width. The board must contain thirty-six through-hole LEDs as well a current limiting resistor per every two LEDs. Three separate circuits divide the LEDs into three groups, for red, blue, and green. Therefore, the board must contain at least four traces spanning the entire board length, including three power traces and a common ground. Since the overall board width is relatively narrow, routing may become somewhat of a challenge if component orientation is not carefully considered. Simply positioning the LED leads so the anode and cathode align with the longest board dimension will permit additional board space for traces routed lengthwise. This example demonstrates how component orientation can affect routing in a design with a high component density. However, in this specific example, additional complications might render the design unusable.
Simplifying a design to operate from fewer components without affecting functionality does not only reduce physical dimensions, but also reduces manufacturing costs. A variety of common LED circuits feature simplified architecture as well superior reliability. Each LED lighting application is unique, and will require circuitry based on the individual details as well as client specifications. A good example of an LED application implanting space conservation is the multi-functional LED taillight cluster. This multi-functional LED taillight cluster offers an amazing example of space conservation in action. This sample product required careful routing and component orientation, but resulted in a high-density design featuring 60 surface mount LEDs. The LED taillight measures 2.5 inches in diameter and approximately 1/8 of an inch in overall thickness. The multi-functional design integrates marker light, brake light, and turn signals functions. The unit is equipped with 80 components including various LEDs, resistors, and Zener diodes. For more information or to purchase this sample product, click on the corresponding link located in the content box found on the upper right hand corner of this page.