Metal Core PCBs Explained

Metal Core PCBs Explained

Dec 06,2021

The ever-increasing demand for PCB manufacturing can be attributed to the advancements in electronics, automation of processes, surge in demand for various consumer appliances and devices, electromechanical devices, and more. All of these sand many other application segments of PCBs have different requirements in terms of PCB materials, substrates, number of layers and more. Some applications may require PCBs which are suited for high temperature environments, and hence metal core printed circuit boards are used here. Metal core PCBs offer many benefits compared to FR4 or any other silicone or polymer material as the PCB base. Metal core boards are those which have conductor metals such as aluminum and copper as their base material. This post discusses the details of metal core PCBs, their benefits, and more.

Metal Core PCBs at Length 

These metal core boards are also called thermal PCBs, thermal clad PCBs, or insulated metallic substrates, and rightly so. This is because the spread the heat almost uniformly in both the directions of the core and across all the layers situated above and below. This protects the board and components from damage. These PCBs are made of a copper foil, metallic plates, and thermal insulating layers. Aside from this, they have a solder mask, circuit layer, dielectric layer, and a metal core layer which is the heat spreader. While overheating is an issue in most electrical components and this is usually done through cooling fans or exhaust fans fitted inside casings or enclosures. However, this is not required in metal core PCBs, as heat spreading takes place through conductive cooling, wherein heat is uniformly transferred from a hot area to a cooler one. Usually, aluminum is the most common core material used in this PCBs as it has a good heat dissipation rate. Aluminum as a metal is tough yet lightweight. While copper is also a good option as a core material and is used in certain applications, it is heavy and expensive. In terms of fabrication too, aluminum is easier to fabricate than copper. A metal core board is typically divided into 3 layers:

  • Copper foil layer
  • Thin dielectric layer for thermal conductivity
  • Thick layer of copper or aluminum core

Typically, it is common to use surface mounting technology (SMT) instead of through hole for metal PCBs. This is because the core being a conductor metal, there is a risk pf short circuits in case of plated through hole mounting. This is especially true in case of electrical applications such as LEDs.

Benefits of Metal Core PCBs

In case of high-temperature applications, the increasing heat may raise the temperature of the circuit boards as well as the components mounted on them, especially if they are made of FR4 or similar plastics. This may lead to overheating as heat dissipation would be limited to the available heat sink. This may lead to impaired functioning or damage. Hence, metal core PCBs are used in such applications as metals help push the heat towards the heat sink and prevent overheating of boards and components. Here are some benefits of metal core PCBs.

  • Metals are good conductors of heat and electricity, and hence facilitate faster heat transfer.
  • These metal cores are etched onto the circuit boards, which helps keep the heat away from the central components and wiring.
  • Metals like aluminum and copper are durable, safe, and long lasting, and do not have toxicity issues such as lead.
  • They are resistant to vibration, and help protect the components from coming off, especially in high-vibration applications.
  • Metal cores offer better structural and dimensional stability as well as strength to the board.
  • Metals are recyclable and in fact aluminum is lighter than most epoxies and FR4.

If you have a demanding and high temperature application, wherein you need to install a PCB assembly in any equipment or as part of an integrated system, opting for metal core PCBs would be a wise decision. This applies especially if you are an OEM of LED lighting systems as metal core PCBs have a huge application in this segment. However, ensure you partner with a reliable and experienced PCB manufacturer and service provider who would understand your requirements and customize accordingly. Creative Hi-Tech is a well-known PCB manufacturer and assembly services provider who specializes in custom PCB designs and assemblies. They offer metal core PCBs for demanding applications.

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