Metal Core PCB

What is a metal core PCB?

A metal core printed circuit board (MCPCB) also known as thermal PCB, incorporates a metal material as its base as opposed to the traditional FR4, for the heat spreader fragment of the board. Heat builds up due to some electronic components during the operation of the board. The purpose of the metal is to divert this heat away from critical board components and towards less crucial areas such as the metal heatsink backing or metallic core. Hence, these PCBs are apt for thermal management.
In a multilayer MCPCB, the layers will be evenly distributed on each side of the metal core. For instance, in a 12-layer board, the metal core will be at the center with 6 layers on the top and 6 layers at the bottom.
MCPCBs are also referred to as insulated metallic substrate (IMS), insulated metal PCBs (IMPCB), thermal clad PCBs, and metal-clad PCBs. In this article, we will be using the abbreviation MCPCB to avoid ambiguity.
The MCPCBs are made up of thermal insulating layers,metal plates, and metal copper foil.

The basic structure of MCPCB comprises of the following:

  • Solder mask
  • Circuit layer
  • Copper layer – 1oz. to 6oz. (most commonly used 1oz. to 2oz.)
  • Dielectric layer
  • Metal core layer – heat sink or heat spreader

Why metal core PCBs?

Accumulation of too much heat in printed circuit boards lead to malfunctions in the devices.

Electronic devices that generate a considerable amount of heat cannot always be cooled using conventional fans. Conductive cooling through metal core boards is an ideal option. In conductive cooling, the heat is transferred from one hot part to a cooler part by direct contact.

This works well since heat constantly seeks to move to any object or medium that is cooler.


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