Some applications require specific properties in their circuit boards. This is especially true for temperature-sensitive applications, one of which is LED lighting. The LED lighting industry is expanding rapidly in response to increased interest in the more efficient and cost-effective lighting method, but much of the functionality of LED lights depends on the temperature of its system.
To help you understand why the LED lighting industry uses PCBs, we’ve outlined the nature of PCB base layers, the attractive qualities of aluminum PCBs and why they work well in the LED lighting industry.
Engineers design printed circuit boards to work best within their particular application. The designs can specify the nature of the circuit, the PCB coating material, the size of the PCB and a variety of other qualities. One of the most basic qualities to change, however, is the core of the circuit board.
PCB bases come in a variety of materials, including:
- FR-4: Most common of these materials is FR-4, a base composed of glass and epoxy. While fire-retardant, FR-4 tends to be relatively inefficient at transferring heat.
- Epoxies: Another, albeit less common substrate for PCBs is a material known as an epoxy. While less durable than other options, epoxy-based PCBs are much cheaper to manufacture.
- Metal-core: Metal-core PCBs are very effective for a variety of applications, specifically those involving heat transfers. These bases consist of metal, usually aluminum, laminated with copper. These metals give the circuit board improved electrical insulation and thermal conductivity.
When thermal qualities are not as important, FR-4 or epoxy bases are more common, as these tend to be relatively less expensive. However, when thermal qualities are important for the proper function of the end product, metal-core printed circuit boards are likely the solution.
ABOUT ALUMINUM PCBS
Most common among metal-core printed circuit boards is the aluminum PCB. This type of printed circuit board is built on top of an aluminum alloy base, instead of a fiberglass base. The alloy usually consists of a combination of magnesium, aluminum and silumin, altering the properties of the metal to best suit the needs of the application. All aluminum PCBs consist of the following layers:
- The Base Layer: The base layer of the PCB is the aluminum alloy sheet upon which the rest of the PCB builds. This alloy is typically designed to provide maximum electrical insulation and thermal conductivity.
- The Thermal Insulation Layer: This layer is extremely important in the design of the PCB. Consisting of a ceramic polymer, this layer protects the PCB from mechanical or thermal damage by offering thermal resistance and viscoelastic properties. This works by absorbing the heat created as the current moves through the circuits and transferring it to the aluminum layer — there it disperses.
- The Circuit Layer: This layer contributes most to the end function of the board, containing the copper foil circuits needed for the PCB to function.
These layers occur in any number of variations, with one or several thermal and circuit layers depending on the particular application. The layers listed also lend a number of different benefits to aluminum PCBs, which can be of use to several key industries.
THE LED LIGHTING INDUSTRY
Light Emitting Diode, or LED, lighting is an increasingly popular lighting solution, favored for its improved longevity and reduced environmental impact. Some of the benefits of LED lighting over conventional methods include:
- Lower Power Consumption: Quality LED lights can be six to seven times more efficient than traditional incandescent lights. On average, switching your home from incandescent lighting to LED lights can cut your energy use by more than 80 percent
- Longer Lifespan: LED light bulbs can have a life of over 25,000 hours, or three years of 24/7 use! This is 25 times longer than any traditional light bulb. This saves you the time, money and effort involved in purchasing and installing new bulbs!
- More Efficient: Traditional incandescent light bulbs release 90 percent or more of their energy as heat. LED lights cut this by up to twenty percent! This means more of your energy is going into lighting your home, and less into unnecessarily heating it.
- Very Compact: Because of their small size, LED lights feature in applications of various sizes and varieties. This means manufactures can insert LEDs into anything from computers and smart phones to cars and traffic lights.
- Mercury Free: LED lights contain no mercury, unlike more traditional options. As a result, LEDs have a smaller environmental impact than traditional bulbs and can be more easily disposed of, without special disposal procedures.
These benefits are incredible, and have lent to the popularity of LED lighting today. As of 2012, Americans installed over 49 million LEDs, saving $675 million in annual energy costs and significantly cutting carbon emissions. You can find LEDs in automobile lighting, traffic lights, TVs and electronics and a variety of other applications.