Ceramic PCB vs. FR4 board vs. Metal core PCB

If you’re using printed circuit boards, you can use the standard fr4 boards or you can go with a metal core printed circuit board (MCPCB). Ceramic printed circuit boards ( Ceramic PCB ) are a type of metal core PCB you may prefer. There’s certainly nothing wrong with fr4 boards, and if you’ve been using them effectively in your business, you will probably want to continue to do so. But just in case, it’s a good idea to understand the distinctions between standard fr4 boards and metal core boards.

Which you choose will depend on the demands of the particular applications for which you will be using your printed circuit boards. So what are the various advantages and disadvantages of fr4 boards vs. MCPCB or ceramic boards?

Fr4 vs. MCPCB

One of the main reasons why you would avoid fr4 vs. a ceramic circuit board or other MCPCB board has to do with heat transfer. Metal cores like aluminum nitride and beryllium oxide are extremely thermally conductive. fr4 PCB material is not. If you are using your boards in applications where heat is a real issue, like LED lighting, you will probably want to move away from standard fr4 boards towards ceramic boards or other metal core PCBs, as metal core boards can more easily carry excess heat away from hot spots that can ultimately damage the board by reducing the life of semiconductor junctions.

Other metal core PCB materials in addition aluminum and beryllium can include copper and steel alloy. Steel alloys provide a stiffness that you will not get with copper and aluminum, but are not as effective at heat transfer. Copper has the best ability to transfer and dissipate heat as part of your printed circuit boards, but it is somewhat expensive — so companies on a budget producing or purchasing many printed circuit boards will often opt for aluminum as a cheaper but still highly effective heat-dissipating alternative to fr4 boards.

Aluminum Printed Circuit Boards

For most businesses, the most cost-effective solution will be metal core printed circuit boards with an aluminum base. You get good rigidity and thermal conductivity at a more reasonable price. For this reason, if you order metal core printed circuit boards and do not specify copper, you can usually expect an aluminum core.

How Metal Core PCBs Dissipate Heat

The reason metal core PCBs are so much more effective at dissipating heat than fr4 boards is due to their thermal conductivity dielectric material, which serves as a thermal bridge from the IC components to the metal plate, automatically conducting heat through the core to a heat sink. If you have fr4 boards, you must add a topical heat sink to transfer heat through the board or it will create potentially damaging hotspots.

Other Advantages of MCPCBs

In addition to preventing hot spots, a metal core PCB’s thermal conductivity properties also result in less thermal expansion and, as a result, greater dimensional stability. Thermal expansion can cause different layers of the board to take on different shapes or sizes, affecting the integrity and functionality of the board. Protection from thermal expansion is desirable.

Where Would I Use a Ceramic Circuit Board or Metal Core PCB?

It’s important to understand that there are many circumstances where the use of an FR4 board is indicated and perfectly acceptable. Certain applications, however, will call for a ceramic or other metal core PCB to avoid putting your product at risk. These include:

•     LED lights, especially spotlights and high-current LEDs

•     Cars, especially power controllers, variable optical systems, exchange converters and power regulators for cars

•     Industrial power equipment

•     Printers

•     IC arrays

•     Semiconductor refrigeration devices

•     Audio amplifiers

•     High power transistors and transistor arrays

•     Solar cell substrates

•     Other power applications, like DC converters and regulators

What Types of Metal Core PCBs Are Available?

Metal core printed circuit boards are available as single-layer PCBs, single-layer Chip-on-Board PCBs, double-layer PCBs, double-sided PCBs, and multi-layer PCBs. Once again, which you chose will depend on your personal PCB application needs.