What’s an Aluminum PCB and Why Should You Care?

Printed circuit boards have different layers in their design. Some layers are used for electrical conductivity, and others are used for offering insulation between layers. The conductive layer comes with different types, such as glass epoxy, which is FR4 material, polyimide material, and ceramic substrate.

Engineers use materials based on board features to get good electrical and mechanical parameters. Here we will discuss aluminum PCBs. How is it different from other PCB substrates, its advantages and applications, and how can we take advantage of it in our board designs?

Table of Contents

What is an aluminum PCB?

Aluminum PCB, also called MCPCB or metal clad PCB board, aluminum clad, and IMS.
The stack-up layer for the aluminum board is like a normal board. The substrate is different; a mixture of aluminum alloy is used as the core material. That is a combination of glass epoxy or also a metallic substrate.
The aluminum layer exists on one side, and the other is a copper layer that has circuit routing. The manufacturing process of a single-layer aluminum board is easier and simpler than a multi-layered one.
These boards are low-weight, and the use of aluminum cladding increases thermal dissipation for current flow.

Properties of Aluminum Board

Heat Dissipation

For protection of circuit damage and component burning, the use of aluminum clad is best. The thermal resistance for the same thickness for FR4 and aluminum board is a low value. It can easily spread heat smoothly on board with at the time of overheating. For high power and high density, aluminum boards provide good heat dissipation.

Less Weight

Aluminum is a low-weight material, and PCB is made with this material alloy. The weight of MCPCB clad is less than FR4. In different applications, PCBs are used for the strong and compact nature that is provided by aluminum cladding.

Coefficient of Thermal Expansion

The stable nature of aluminum is good since it has a low CTE value. The board and components do not have shrinkage features and expansion since they have thermal dissipation. The board has features for longevity and stable design.

Cost-effective

Aluminum is low-cost option than other conductive materials. So manufacturing boards are low-cost with metallic substrates.

Other Properties

These boards are reliable to use for a long time. They do not come with toxins for affect the environment. It is easy to recycle, and PCB made with metallic cores has features to handle wear and tear for longer use. The EMI features are good and also have insulation strength.

Types of Aluminum PCBs

Universal PCB:

This board comes with a substrate for manufacturing that is glass epoxy.

High-Frequency (Microwave Aluminum):

This type uses polyolefin resin or polyimide resin for dielectric material.

High-Thermal PCB:

The dielectric material is made with highly conductive epoxy resin.

Application of aluminum PCB

LED Lighting Circuit

High power is used for operating LED and lamp circuit boards; it produces heat that is handled with the use of aluminum boards. These LEDs provide high glow and different color combinations. Energy efficiency LEDs are now becoming famous and are made with metallic cores.

Amplifiers

Different types of amplifier circuits, such as audio amplifiers like input and output amplifiers, preamplifiers, and power amplifiers, are made with the use of metal clads of aluminum alloy.

Consumer Electronics

The devices, such as mobile phones and tablets, are lightweight and have a compact design. Their board uses aluminum materials for the base and makes the circuit low weight. Computer devices, microwaves, ovens, and other devices are these boards.

Medical Field

Measuring tools like CT scans, MRIs, and BP meters work through accurate and reliable devices. The longer working life needed that provided with aluminum boards. These devices come with a high intensity of components for sensitive operations. The use of aluminum base allows us to put larger components and make the board low weight.

Other Fields

The automobile, communications, and aviation industries, and electronics use aluminum boards. Some other devices, like power regulators and inverters, rectifiers, also use MCPCB.

Aluminum PCB Limitations

Either aluminum board has many features, but for high-demand features like flexibility, strength, and resistance to vibration, there are some difficulties in using aluminum as a base for PCB production.

Flexible boards come with features to bend at any angle without circuit effects.

Smartwatches and folded screens needed special machines and quality control processes that affect cost value.

For milling and drilling holes on board, there are rough edges left that affect board conductivity. So laser and micro-drilling devices are used for cleaning holes.

Comparison between Regular PCBs and Aluminum PCBs

Difference Between FR4 and Aluminum PCB

Regular or Standard PCBs

These boards come with copper and dielectric materials for holding layer stack up. The PCB substrates are fiberglass epoxy, ceramic, and PTFE (polymers).

Aluminum PCBs

The aluminum board’s inner structure is the same; just the substrates are replaced with metallic aluminum alloys. The substrates combined with FR4 fiberglass epoxy for manufacturing

Differences

The simple manufacturing process is high for the standard boards as a result of the easy availability of different substrate materials.
Customization is also easy for standard boards for conductivity, dielectric features, and thermal dissipation.
Multilayer boards are also made with the use of FR4 substrate. The process of manufacturing increases the cost for aluminum metallic clad.
Low-power uses boards, and low-vibration intensity boards are best for aluminum cores.
Flex boards are made with fiberglass epoxy regular boards, and bending features are not obtained with metal cores.
The cost of a regular board optimized with a balancing of manufacturing features and metallic alloy processes is expensive and time-consuming.

Summary

The main features of using metal substrates are good heat management and durability and reliability of long-term features. But the easy use in design is to get from the standard board; there are layers added and increased conductivity, and it helps to reduce costs for production. As compared to the features of standards and aluminum boards, it helps for selection criteria before design. For low power, low temperatures, and simple applications, MCPCB aluminum is the best option to use. Proven PCB manufacturers can provide all this related information and the best solution to the customers.