What are aluminum printed circuit boards?

A printed circuit board may be created in many different ways. However, Aluminum printed circuit boards are one kind that has a reputation for being good at dissipating heat. Other names for it include aluminum clad printed circuit board, metal clad printed circuit board, and even thermally conductive printed circuit board. It all comes down to the fact that they are all made of aluminum and function in the same manner.

Aluminum PCB

One of the most popular metal core PCBs is the Aluminum printed circuit boards, also known as MC PCB, aluminum-clad, an insulated metal substrate, etc. The aluminum PCB's fundamental structure is not much different from that of other PCBs. Its distinctive feature is the metal base. A typical aluminum PCB has four layers: an aluminum substrate layer, an insulating dielectric layer, a copper foil layer for the circuit, and an aluminum base membrane (protective layer).

ALUMINUM PCBS: HOW ARE they created?

Between a metal base and a copper foil, a thin layer of thermally conductive but electrically insulating dielectric is layered. The appropriate circuit layout is etched onto the copper foil, and via the thin dielectric, the metal base conducts heat away from this circuit.

Bottom layer

This foundation is made of a substrate made of an aluminum alloy. This sort of PCB is an excellent option for through-hole technology, which will be covered later in this article, thanks to the usage of aluminum.

Layers of thermal insulation

This PCB module is of utmost importance. It incorporates a ceramic polymer that protects the PCB from thermal and mechanical loads and has great heat resistance.

Wiring layer

The copper foil that was previously stated in this article is present in this layer. Most often, copper foils weighing between one and ten ounces are used by PCB producers.

As current circulates through the circuits, heat is absorbed by the dielectric layer of insulation. This causes the heat to be transmitted to the aluminum layer, which disperses it.

To produce the lightest possible, more heat is produced. Improved heat resistance on PCBs increases the lifespan of your completed product. You will get heat mitigation, improved protection, and component dependability from a qualified manufacturer.

The composition of aluminum PCBs

FR4 PCBs and Aluminum printed circuit boards have a lot in common. Four layers make up the fundamental structure of aluminum PCBs. It is made up of an aluminum base membrane, an aluminum base layer, copper foil, and a dielectric layer.

• Layer of Copper Foil

Compared to standard CCLs, the copper layer in use is considerably thicker (1oz to 10oz). A thicker copper layer has a greater ability to transport current.

• Layer of Dielectric

The dielectric layer, which ranges in thickness from 50 microns to 200 microns, is thermally conductive. It is suited for the application and has low heat resistance.

Base: Aluminum

The aluminum foundation, which is the third layer, is constructed of aluminum substrate. High thermal conductivity is present. A layer of Aluminum Base Membrane

The membrane with an aluminum base is picky. It acts defensively by protecting the metal surface against unintentional etching and scratching. It comes in two varieties: lower than 120 degrees or about 250 degrees (anti-high temperature)

Aluminum PCB Manufacturing Difficulties

The manufacturing procedure is essentially the same for PCBs made entirely of aluminum. Here, we'll go through the primary production procedures, issues, and fixes.

First Step: Copper Etching

Aluminum printed circuit boards employ copper foil that is a little bit thicker. However, width settling is necessary for the etching if the copper foil weighs more than 3 oz. After etching, the trace width will be outside of tolerance if it does not meet the design requirements. Because of this, the trace width adjustment should be carefully planned. In the production process, the etching factors must be managed.

Second Step: Solder mask printing

Aluminum PCB solder mask printing is tough because of the thick copper foil. This is because printing solder masks will be challenging if the trace copper is too thick and the etched picture has a significant variation between the base board and trace surface. Therefore, it is preferable to employ two-time solder mask printing. The solder mask oil that is used should be of good quality, and in certain circumstances, resin filling is completed before solder mask application.

Third Step: Manufacturing of mechanical goods:

Molding, mechanical drilling, v-scoring, and other processes are all part of the mechanical manufacturing process. It remains on the internal via. Electrical strength tends to decline as a result. Therefore, for low-volume product manufacture, professional milling cutters, and electric milling cutters should be employed. To avoid burr generation, the drilling settings should be changed. Your mechanical manufacturing will benefit from this.

PCBs made of aluminum are categorized

There are three types of aluminum PCBs.

1. Universal Aluminum PCB: Here, an epoxy glass fiber pre-preg dielectric layer is employed as the dielectric layer.

2. High-frequency aluminum PCB: Polyolefin or polyimide resin glass fiber pre-preg is used as the dielectric layer.

3. High Thermal-Conductive Aluminum PCB: Epoxy resin is used to create the dielectric laver. High heat conductivity is required for the resin.

Aluminum PCB types

Three basic categories of aluminum PCBs exist:

Adaptable Aluminum:

The dielectric utilized in these boards is flexible. Flexibility is substantially increased. A flexible PCB is utilized to fit into diverse forms better than a rigid board could when there is a space limitation in the design.

Hybrid Aluminum:

A hybrid aluminum PCB is frequently employed when dealing with RF applications. With through or metal-backed plating, Candor surpasses the uniform plating requirements for RF applications.

Aluminum with Through-Hole:

These kinds of circuit boards have an aluminum foundation that has pre- or post-laminated holes. With this technology, there is a significant level of heat tolerance, robust physical connections, and simpler prototyping.

Workings of aluminum PCBs

Additionally, the following special benefits come with employing aluminum substrates:

1. Complies with RoHS (Restriction of Hazardous Substances) regulations

2. Better suited to surface-mounted technology (SMT) processes.

3. Thermal diffusion is very effectively handled in terms of circuit design, lowering the operating temperature of the module, increasing service life, and enhancing power density and reliability;

4. optimizes the mix of power circuits and control circuits; decreases the assembly of heat sinks and other hardware (including thermal interface materials), reduces product volume, and lowers hardware and assembly costs; and

5. Replaces brittle ceramic substrate PCBs with stronger metal ones for improved mechanical durability.

Application of Aluminum PCB

Typical uses include:

1. Audio gear, such as balanced amplifiers, audio amplifiers, preamplifiers, power amplifiers, and input-output amplifiers.

2. Power supply: SW regulators, switching regulators, DC/AC converters, etc.

3. Tools for communication, including electrical devices, high-frequency amplifiers, filtering devices, and sending circuit

4. Motor drivers, office automation devices, etc.

5. Regulators, igniters, power controllers, and other automotive electronics

6. aluminum core PCB for led tube lighting.

With the growth of energy-saving lighting, the market has warmly embraced a variety of effective and bright LED lights, and the aluminum substrates used in LED lamps have also started to be employed extensively.

PCBs with aluminum bases have advantages.

1. Improved temperature control

We all know that when electronics are functioning at fast speeds, high-temperature conditions will arise. The components at high temperatures may soften, distort, alter in characteristics and performance, and even pose safety issues if the thermal energy cannot be swiftly diverted away. Aluminum bases quickly dissipate heat from components, enabling the creation of PCB designs with high power and density. Ten times more heat can be dissipated by aluminum PCBs than by fiber-glass foundation PCBs.

2. Outstanding mechanical stability and reduced weight

The strong physical endurance of aluminum alloy-based materials may lower the danger of breaking during shipping and regular usage. And the metal aluminum is lighter. Compared to other metal PCBs of the same weight, it may provide more strength and flexibility.

3. Affordable prices with little environmental harm

Because it is a non-toxic metal and is simple to extract, aluminum is more affordable and environmentally friendly than other metal bases. And when the components with high needs for heat dissipation are integrated on an aluminum board, fewer extra radiators are required. Using aluminum PCBs offers lower production and material costs.

Read more: A detailed guide to understand the PCB Fabrication process

Conclusion

The aluminum board has to be your priority if your PCB design has a heat dissipation issue. All varieties of aluminum printed circuit boards, including single-sided, multilayer, hybrid, flexible, through-hole, and aluminum PCBs, are offered by EuropePCB. There are also more kinds, including high-frequency aluminum PCBs, universal aluminum PCBs, and aluminum PCBs with high thermal conductivity. If you would like more information about our aluminum PCBs, don't hesitate to get in touch with us.