What Is a Metal Core Printed Circuit Board?

A metal core printed circuit board (PCB) is a thin, flat sheet of material that holds various electronic components, including chips, and is used in electronic equipment, especially computers. A metal core PCB is similar to a standard PCB, except it has a metal layer added to offer several advantages. The most common advantage is that the metal core is better suited to relieving heat than other materials, so the metal core printed circuit board does not need as many fans; metal core boards also are not subject to the heat-related changes in size that other PCBs suffer. On the downside, these PCBs often are thicker, so they may not be appropriate for every system. Aluminum usually is used as the metal core, but copper and alloys also are common.

When a PCB runs, heat is generated by the power and electricity going through the system. If this heat is not reduced to a manageable amount, then the system can catch fire, the PCB’s longevity can be reduced, or the PCB can immediately stop working. Fans and heatsinks normally are used to relieve the heat, but a metal core printed circuit board uses a metallic core inside the PCB itself. Metal conducts heat well, so the heat is directed toward the metal and away from important areas of the PCB.

Thermal expansion, which can cause a PCB to expand from exposure to heat, can be a big problem. After the PCB expands, it may no longer be able to fit into the system, or there may be other functionality issues. While a metal core printed circuit board cannot entirely relieve this problem, it greatly reduces it. Metal is not as susceptible to heat, making the boards more stable under working conditions.

The main disadvantage to using a metal core printed circuit board is its size. The metal layer is added to the PCB, which slightly increases the size. The size normally is increased only by about 0.1 inch (2.54 millimeters), but this is enough to keep a PCB from fitting into some systems. This means some compact systems may not be able to use this PCB without some modifications being made.

Several metals are stable under the high heat produced by a system. The most commonly used metal for a metal core printed circuit board is aluminum, because it is easy to produce and can take heat very well. Copper is the second most common metal, after which comes alloys made from other stable metals.