When you think of Printed Circuit Boards (PCBs), images of FR4 or CEM3 boards usually come to mind. These are seen as appropriate circuit board materials as they are able to provide application benefits like heat dissipation, while supporting components such as heat sinks and metal cores. However, there are still a few applications that require metallic components to be used in the PCB’s construction. For this reason, many manufacturers provide aluminum PCBs to clients.
What are Aluminum PCBs? Also known as metal base PCBs, aluminum based PCBs comprise metal based laminates that are covered by copper foil circuit layers. They are constructed utilizing alloy plates, which consist of a combination of Aluminum, Magnesium, and Silumin (Al-Mg-Si). These PCBs are known for their beneficial features such as electrical insulation, good thermal potential, and high machining performance.
Aluminum PCBs differ slightly from general PCBs. The structure of this PCB comprises:
Base Layer: This layer consists of an aluminum alloy substrate. The use of aluminum makes this PCB an excellent choice for PTH technology. Holes can be cut, punched, or drilled to the requisite sizes.
Insulation Layer: While the base layer is certainly important, the thermal insulation layer is a critical component of this PCB. It consists of a special ceramic polymer, which has excellent viscoelastic properties and thermal resistance. The insulation layer also protects the PCB from thermal and mechanical stresses.
Circuit Layer: This layer comprises the copper foil mentioned earlier. Generally, PCB manufacturers utilize thick copper foils, which can range from 1oz to 10oz.
There are certain materials and processes that can be used to augment the performance of the PCB. These include gold plated HAL, lead free RoHS assembly processes, immersion gold silkscreen, and OSP anti-oxidation processes.
While aluminum PCBs consist of the same width and thickness as FR4 PCBs, the alloy plate allows the PCB to increase its conductivity to 2.0. Also, it can carry higher currents and withstand up to 4,500 volts of electricity.
Advantages and Features
While PTH may be an appropriate option, aluminum PCBs can also be mounted with Surface Mount Technology (SMT).
The PCB reduces the product’s operating temperatures.
It increases the power frequency of the product.
It extends overall life of the product.
It is cost-effective as you require a smaller amount of hardware, which leads to lower assembly costs, and ultimately results in a smaller environment footprint.
The aluminum provides mechanical durability, making it a perfect replacement for ceramic based PCBs.
Industrial Applications The beneficial features of aluminum PCBs make it an appropriate option for a variety of industrial applications. These include automobiles, power supplies, audio devices, computers, lighting applications, and electronic communication equipment.
Perhaps the most popular example, aluminum PCBs are widely used in LED lighting applications. They are especially effective in the manufacturing of energy saving lamps.
In terms of power supplies, you will find these PCBs in AC/DC converters and switching regulators.
You can also find them in various audio devices like power, audio, and input/amplifiers.
For automobile applications, aluminum PCBs prove to be useful in supporting equipment like ignition systems, power supply controllers, and regulators for automobile electronic systems.
A few computer devices such as CD drives, CPU motherboards, and internal power supplies for heatsinks and lighting can be supported with the help of aluminum PCBs.
Communication equipment that makes the use of aluminum PCBs are high frequency amplifiers and transmitter circuits.
Aluminum PCBs have proven to be an excellent alternative to general PCBS for a variety of industrial applications.