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Aluminum vs. Standard PCBs

In PCB creation, every material counts. Circuit boards with aluminum cores (aluminum PCBs) have different properties from boards without metal substrates (standard PCB’s). These two popular board types power a variety of commercial and consumer electronics. Will an aluminum or standard PCB suit your project best? The answer depends on your intended application.

What Are Standard PCBs?

Standard PCBs use a dielectric and copper as their most prominent metal consist of different layers of material. They feature a substrate, or base, made from fiberglass, polymers, ceramic or another non-metal core. Many of these PCBs use FR-4 for the substrate. This fiberglass material has a relatively affordable price and moderate durability. Additional layers of copper, solder mask and silkscreen make the board conductive and outline component locations. These layers may appear on one side of the base, both sides or in a multilayer stackup.

You can find standard PCBs used in a nearly infinite number of applications. Their capabilities depend on their materials and construction, so they power low-end and high-end electronics alike. Single-sided PCBs appear in less complicated devices such as calculators, while multilayer boards have the potential to support space equipment and supercomputers.

Advantages and Disadvantages of standard PCBs

Standard PCBs are well-rounded and adaptable. You have multiple substrate options that determine the board’s price and durability. If you have a low budget and low-intensity purpose, you can choose cost-effective fiberglass. On the other hand, you can invest more in a stronger base material that handles higher levels of stress. Radio-frequency substrates and flex substrates suit specialty applications.

However, FR4 circuit boards require extra components to withstand high-temperature applications. Non-metal substrates do not have thermal conductivity, so you have to add a material that does. If your device has a high-power or high-density design, the circuits become prone to stress and damage. You must add heat sinks, copper-filled vias or forced air to direct heat away from the circuits.

What Are Aluminum PCBs?

An aluminum PCB has a similar layout to any other PCB. It has a layer or layers of copper, solder mask and silkscreen layered over it. Instead of having a fiberglass or plastic substrate, though, an aluminum circuit board has a metal substrate. This base mainly contains a combination of aluminum. The metal core can consist entirely of metal or have a combination of fiberglass and aluminum. Aluminum PCBs typically are single sided, but can be double sided as well. Mulilayer Aluminum PCBs are highly difficult to manufacture.

Aluminum boards get the most use in LED and power converting electronics. The intense light produced by LEDs creates high levels of heat, which aluminum directs away from components. An aluminum PCB extends the lifespan of an LED device and provides more stability. You can find aluminum substrates in street lights, stop lights and household lighting. They allow power converters to change currents and regulate electronics. Creators in many other industries also find use in aluminum PCBs, but they don’t implement them as often.

Pros and Cons of Using an Aluminum Substrate

Aluminum boards are one of the most thermally conductive PCB options. They keep as much heat away from vital components as possible to ensure minimal circuit damage. Thanks to their high heat tolerance, they can handle higher density circuits and larger power levels. Substrates created from aluminum alloys have a high level of physical durability that lowers the risk of breakage. Compared to other metals, aluminum has a lower environmental impact in addition to a reasonable cost.

On the other hand, aluminum PCBs tend to have more niche uses than standard boards. While they cost less than adding conductors to a copper board, they have a higher price than standard PCBs without those components. Investing in an aluminum core may not pay off if your application doesn’t involve high temperatures. If you plan on creating a flex circuit, an aluminum flex PCB can only flex into its initial position. It will bend to fit into smaller electronics, but it won’t withstand the stress of vibration.

Which Type of Conductive Layer Will Work Best for My Project?

You have numerous factors to consider when deciding on your board’s substrate. In general, aluminum core PCBs suit applications with high heat dissipation requirements. Their properties allow for higher power and higher density designs than standard PCBs. However, creators with lower budgets or specialty applications may benefit more from boards with non-metal substrates. As an example, a flex circuit with a polymer substrate handles vibrations more effectively than a flex aluminum circuit. For more help choosing a substrate, contact the experts at MCL today.

PCB Glossary

  • Router

    A machine that cuts away portions of the laminate to form the desired shape and size of the printed board.