Metal core PCBs have emerged to become an essential and go-to solution for LED applications and High power applications be it commercial, automotive or Industrial equipment. Metal core circuit boards offer impressive thermal management capabilities at a cost hard to match with other materials with similar capabilities. However choosing between metal core printed circuit boards also requires a thorough understanding of properties, design considerations, cost, availability, etc. which are required to match your requirements. This article will give you a brief idea of factors to be considered before choosing a metal-core circuit board for your requirements.

Why Metal Core PCB?

Metal core PCBs are special PCBs that use a metal core instead of an epoxy resin core and a thermally conductive dielectric layer for insulation. The metal core of the PCB causes the heat generated by the components to dissipate heat away from the components uniformly. The key benefits of using a metal core circuit board are-

  • Superior Thermal Management – Metal core circuit boards are known to have excellent thermal management capabilities allowing the use of components like high-wattage LEDs that might damage the PCB or damage itself during normal operations. 
  • Enhanced Durability and Mechanical Strength- Metal Core printed circuit boards are extremely durable and are known for their mechanical strength due to the metal core. 
  • Improves Performance of High-power Electronics – Metal core circuit boards can dissipate heat generated by high-power electronics quite effectively. At high temperatures most of the high-power handling components start losing efficiency and may cause a reduced lifetime, therefore dissipating heat generated by such components is important.

Metal core printed circuit boards are extensively used in high-wattage LED applications, high-power applications, automotive applications and industrial applications. 

Choosing the Right Metal Core Material 

Choosing the material of any PCB is a crucial aspect of the performance of any PCB. Metal Core PCBs are no different, their performance and cost are loosely dependent on the material used. Metal core circuit boards have two parts, the dielectric and the metal core. 

  • Types of Metal Cores

There are not many kinds of metal-core circuit boards available in the market, but the variety available is usually more than sufficient for most of the applications that require metal-core circuit boards. They are –

  1. Aluminium Core – Aluminium metal core printed circuit boards are the most common metal core material used. Aluminium metal core circuit boards are not only cost-effective, they are easy to manufacture and are widely available. In fact, the most common metal-core printed circuit boards are single-layer aluminium core PCBs. It has an excellent thermal conductivity of around 1-3 W/m·K which is one of the highest among all the PCBs but less than copper metal core circuit boards.

It has the following advantages–

  • Cost Effective – Aluminium core PCBs are quite cost-effective than other PCBs with high thermal conductivity. Other materials like ceramic materials and other metal core circuit boards are multiple times costlier than aluminium metal core printed circuit boards.
  • Lightweight While Durable  – Aluminium metal core circuit boards are lightweight compared to copper metal core printed circuit boards while being durable and have impressive mechanical strength. 
  • Easily Manufacturable and Widely Available – Aluminium metal core circuit boards are widely available among global vendors. Its high availability can be credited to its ease of manufacturing when compared to other material PCBs of similar thermal properties.

Its disadvantages are –   

  • Lower Thermal Conductivity – While aluminium metal core circuit boards have good thermal conduction it is considerably lower than copper core PCBs and ceramic-based PCBs.
  1. Copper Core – Copper metal core circuit boards are rather rare when compared to aluminium metal core printed circuit boards and are much more expensive to fabricate and manufacture. It is renowned for exceptional thermal management and durability. With a significantly higher thermal conductivity than aluminium-based metal core circuit boards. It has the following advantages –
    • Excellent Thermal Management Capabilities – Copper metal core printed circuit boards have one of the highest thermal conductivity of all types of PCBs. Copper itself is one of the best conductors of heat making it suitable for even extremely high power applications.
    • Excellent Durability and Mechanical Strength –  Copper is much more durable and stronger than aluminium and has the capability to handle high mechanical stress for longer durations. 

Its disadvantages are – 

  • Expensive and Limited Availability – Copper metal core circuit boards are much more difficult to fabricate than aluminium core PCBs since copper is harder therefore few manufacturers can fabricate copper metal core printed circuit boards. Limited availability and difficulty in manufacturability are the core reasons that copper core PCBs are expensive.
  • Higher Weight – Copper metal core circuit boards are significantly heavier than aluminium PCBs and therefore may not be suitable for many applications.     
  • Dielectric Material 

Like all PCBs metal core circuit boards also have a dielectric layer for electrical insulation. Although the dielectric material does provide electrical insulation, it also hinders thermal conductivity. Therefore, it can be said that the thermal conductivity of the metal-core printed circuit board mostly depends on the dielectric material of the metal-core circuit board. Dielectric materials are designed for the host metal core they are supposed to be used with for example it is not necessarily true that a dielectric designed for an aluminium metal core will work with a copper metal core.

A few dielectric materials for aluminium metal core circuit boards are –

  1. Thermal Clad by Bergquist (Henkel) – Also known as T-Clad is one of the most common dielectric materials used in metal core printed circuit boards.
  2. Tlam AL by Liard – It is a popular dielectric material designed for cost-sensitive applications.
  3.  VT-4A by Ventec – It is a balanced dielectric material with variants offering both cost-sensitive and enhanced thermal conductivity versions.

A few dielectric materials for copper metal core circuit boards are –

  1. Tlam Cu by Laird – It is a high thermal conductivity material designed for high-power applications and even high-frequency applications. 
  2. VT-4C Series – It is a high-performance material series designed for exceptional thermal management. 

It must be noted that dielectric materials for copper metal core printed circuit boards can be quite expensive and do not generally have a cost-effective option like aluminium core PCBs.

Why Choose Aluminium Metal Core PCB?

Aluminium PCBs are generally sufficient for most of the general metal core PCB applications. It has good thermal conductivity, good durability, and is cost-effective. 

So it can be said that aluminium metal core circuit boards are suitable when the application requires a balance of thermal performance, cost and availability. Some applications may include common LED lighting, power supply PCBs and automotive lightings.

Why Choose Copper Metal Core PCB?

Copper-core PCBs are generally used for specialised applications. It has better thermal and electrical properties than aluminium metal core circuit boards while being heavier and significantly more costly. Choose Copper Core PCBs when you need maximum heat dissipation capability, high power handling, extreme durability and if the budget allows it. Some applications may include power electronics, RF amplifiers and industrial applications.

Conclusion

Metal core circuit boards have been used in many areas such as high power devices and energy saving systems. This kind of board is relatively difficult to fabricate Because the base material of this kind of circuit board is metal, the drilling accuracy and surface smoothness are relatively difficult to ensure than ordinary boards. Therefore, a reliable PCB fabrication manufacturer is an important point to ensure the quality of metal plates. The current new technology is also booming, so manufacturers should also keep up with the current market demand, with new technology to produce boards that can meet customers.

TIME BUSINESS NEWS

JS Bin