PCBs (printed circuit boards) can be constructed using various metal components. These unique printed circuit boards are commonly called metal core PCBs (MCPCBs). During the construction of these PCBs, the metal chosen by the manufacturer will vary according to the PCB’s application. However, out of the many metal components available for use in the construction of PCBs, Aluminum is one of the most commonly used metal components.
PCBs made out of aluminum feature copper-clad and metal-based laminates, which makes them excellent in terms of thermal conduction and electrical insulation. These two features also help these PCBs deliver high-quality performance.
But these advantages scratch the surface regarding the wonders of Aluminum PCBs and what these PCBs can do.
What exactly is an Aluminum PCB?
An Aluminum PCB bear a layout that matches that of other, regular PCBs. It bears layers or a layer of copper layered over by silkscreen and solder mask. However, instead of having plastic or fiberglass substrates, an aluminum PCB has a metal substrate.
An Aluminum PCB mainly consist of a combo of Aluminum, and their metal core can be made out of a metal substrate entirely (hence aluminum core) or out of a combo of Aluminum and fiberglass to produce hybrid aluminum PCBs.
Aluminum Printed Circuit Boards are typically single-sided. However, some are constructed double-sided.
A Multilayer Aluminum Printed Circuit Board is challenging to manufacture.
Aluminum PCBs are primarily utilized in power converting devices and Light Emitting Diodes (LEDs). The extreme light that LEDs produce makes them generate a lot of heat. To eject this heat away from the LED components, manufacturers utilize Aluminum PCBs, which work perfectly. In doing so, aluminum PCBs have been found to extend an LED’s lifespan while at the same time providing more stability to the components.
Aluminum substrates are also utilized in household lighting, stop lights, and street lights. In these applications, CHEAP aluminum PCBs let power converters transform current while at the same time regulating the electronic.
Manufacturers in other industries have also found ways to implement Aluminum Printed Circuit Boards in their fields. However, they do not implement them that often.
Why should you opt to utilize Aluminum PCBs?
Aluminum effectively ejects excess heat produced by electronics away from crucial components. In doing so, these PCBs minimize the adverse effects of heat on the Printed Circuit Board components making the board effective.
Besides ejecting excess heat from electronic gadgets effectively, Aluminum provides durability and strength to products that fiberglass or ceramic bases can’t.
Pros and Cons of Aluminum PCBs
Pros
Aluminum PCBs are thermally conductive PCBs. As a result, they dissipate heat away from crucial components ensuring minimal damage occurs to the circuit due to heat.
Moreover, an aluminum circuit board can also handle significant power levels and high-density circuits due to their heat tolerance.
Substrates constructed using an alloy of Aluminum have also been found to bear higher levels of physical durability, making them less prone to breakage.
Other Pros of Aluminum PCBs
Aluminum Substrate is Cheap
You can easily find aluminum metals in many climates. Therefore, this metal is easy to find, mine, and even refine. Due to this reason, aluminum metal comes at a relatively lower cost when compared to other metals that are harder to find.
Hence, at the end of the day, you’ll find products made out of Aluminum relatively cheaper, including aluminum PCBs.
Aluminum PCBs are Environmental Friendly
Aluminum metal is not just non-toxic; it is also recyclable. What’s more, manufacturing products using Aluminum helps in terms of conserving energy because aluminum assembly is easy. Therefore, when you utilize this metal to create your PCB, you will be keeping this planet healthy and clean.
Heat Dissipation
The extreme heat generated by some electronic components, for example, LEDs, can easily cause damage to your PCB.
Therefore, when developing a Circuit Board, you should consider the heat dissipation factor significantly.
Aluminum is excellent in terms of dissipating heat away from crucial components hence holding the PCBs integrity intact and boosting its durability.
Lightweight Aluminum Substrates
Even though Aluminum is pretty durable, it is also surprisingly lightweight. Aluminum adds resilience and strength without even adding on additional weight. That means that you get a great PCB that is pretty portable.
Cons of Aluminum PCBs
The Double-sided Issue – The current market mostly features single-sided Aluminum PCBs. That is because an aluminum PCB manufacturer has a hard time producing a double-sided Aluminum PCB.
Halide Ions Attacks – Aluminum is more prone to halide ions attacks, most commonly from chloride.
Structure of aluminum pcb
An Aluminum PCB is an Al-based CCLs. In terms of structure, an Aluminum PCB greatly resemble the most commonly used FR4 PCB.
The basic structure of aluminum PCBs consists of 4 layers namely:
– A dielectric layer
– A copper foil layer
– An aluminum base membrane
– An aluminum base layer
Dielectric Layer
Aluminum PCBs have a dielectric layer that is around 50 – 200μm thick. The dielectric layer of an aluminum PCB is a thermally conductive layer that bears low thermal resistance. These characteristics make this layer perfect in terms of its application.
Copper Foil Layer
Aluminum PCBs utilize a thick copper foil layer that is thicker than that of a normal CCL. With this thick copper foil layer, aluminum PCBs can carry larger current capacities, which boosts their performance.
Aluminum Base Membrane Layer
The base membrane of an Aluminum PCB is pretty selective. That is because this circuit layer bears a unique role of protecting the aluminum PCB from unwanted etching and scraping.
There are two types of aluminum base membrane layers, namely:
– Lower than one hundred and twenty degrees
– Around two hundred and fifty degrees
Aluminum Printed Circuit Boards Performance
High Thermal Conductivity
Commonly used PCB substrates, for example, CEM3 and FR4 substrates, are poor in terms of conducting heat.
If the heat an electrical component generates is not dissipated in time, this might cause a lot of damage to the device in use, maybe even rendering it useless. Hence heat dissipation is crucial.
An Aluminum substrate is excellent in terms of thermal conductivity. They effectively conduct heat away from crucial electrical components regulating a gadgets temperature which saves you a lot of trouble.
Thermal Expansion
A PCB made out of an aluminum substrate easily solve the issue of heat dissipation. In doing so, these PCB also indirectly solve the problem of thermal expansion.
When heat strikes a Print Circuit Board, it causes the board to expand, and the same applies to electrical components.
However, PCBs and the components connected to them are made out of different materials, which all bear varying expansion rates. Hence when the heat is not regulated, some materials tend to expand faster than others causing catastrophic damage.
An Aluminum substrate easily regulate heat; thus, they solve this problem.
Dimensional Stability
PCB made out of an aluminum substrate tend to have higher stability when compared to insulating materials used to insulate PCBs.
For example, when heat rapidly increases from thirty degrees Celcius to around one hundred and fifty degrees Celcius, the dimensional stability of an Aluminum PCB changes from 2.5% to 3.0%.
Bonus Performance
Aluminum PCBs have a shielding effect. What’s more, aluminum substrates boost the physical and heat resistance properties of a PCB at reduced costs.
Categories of Aluminum Based Circuit Boards
Aluminum Printed Circuit Board primarily fall into the following categories:
Universal – A Universal aluminum PCB has an epoxy glass fiber pre-preg dielectric layer.
High-frequency – High-frequency Aluminum PCB has a dielectric layer made using polyolefin or polyimide resin glass fiber pre-preg.
High Thermal-conductive – A High thermal conductive PCB has a dielectric layer made using epoxy resin. However, the epoxy utilized to create this layer has to bear a thermal conductivity that is high.
Application areas of Aluminum PCBs
Aluminum is excellent in terms of heat dissipation. Due to this characteristic and many others, aluminum PCBs have found application in many different areas, which include:
In Audio Equipment
Power amplifiers, audio amplifiers, preamplifiers, balanced amplifiers, input and output amplifiers, et cetera make use of aluminum substrates.
In Power Supply Equipment
DC-AC adapters, stabilizers, conditioners, et cetera utilize aluminum PCBs.
Communication Electronic Gadgets
Manufacturers utilize Aluminum PCBs in filter electrical circuits and high-frequency amplifiers.
Office Auto Equipment
In this category you will find office auto equipment that include, motor drivers bear, utilize Aluminum PCBs to function efficiently.
In Computers and Computer Components
Computer and computer components, such as computer motherboards, floppy disks, power supply units, et cetera, utilize Aluminum PCBs.
Power Modules
Rectifier bridges, solid relay, inverters, et cetera all work with aluminum PCBs.
Microwaves and Switches
Under this category, you will find electrical components such as motor controllers, thermal insulations, semi-conductors, radiators, etc.
Lighting
With the need for power-saving lamps rising, many LED manufacturers are now turning to aluminum PCBs to make their lamps as power efficient as possible. Therefore, most LED lights you see around probably bear aluminum circuit boards underneath.
Conclusion
Aluminum PCBs are, without a doubt, revolutionary. These boards are environmentally friendly, they are affordable, and they are power efficient. All these are characteristics everyone highly appreciates in the electrical market today. What’s more, aluminum is a surprisingly lightweight metal. Therefore, manufacturers, today can generate low-cost, power-efficient lightweight high quality aluminum PCBs, which ultimately results in the manufacturing of gadgets bearing the same features. Hence, if you are having a second thought in terms of utilizing aluminum PCBs, we would suggest you scarp that thought and give these PCBs a shot.
