Just like other printed circuit boards, Aluminum PCBs have layers or a layer of copper, silkscreen, solder mask, all layered all over it. Rather than have the plastic or fiberglass substrate, the aluminum circuit board comes with the metal substrate.
The base majorly has the combination of aluminum. Also, its metal core could be made up of metal completely or have the combination of aluminum and fiberglass. Typically, the aluminum PCBs are single sided. However, they could be double sided too. Furthermore, the manufacturing of the Multilayer Aluminum PCB, as well as Aluminum PCB Assembly is very difficult.
The Aluminum boards are mostly useful in power converting and LED electronics. This intense light that is manufactured by the LEDs help in creating high heat levels that aluminum helps in directing away from the components.
In addition, aluminum PCBs also lengthens the lifespan of the LED device, which will offer more stability. Also, aluminum substrates are useful in household lighting, stop lights, and street lights. Also, they assist the power converters in regulating electronics and changing currents. The creators in majority of other industries also find some usefulness in the aluminum circuit boards. However, these industries don’t use or implement them frequently.
Why Do Manufacturers Use Aluminum in Circuit Boards?
The major reason behind the use of aluminum in circuit board is that it helps in transferring heat from important components. Therefore, it helps in reducing any harmful effect that it can have on your circuit board.
Another important reason is higher durability. Aluminum provides durability and strength to the product which the ceramic or fiberglass bases cannot.
What are the Disadvantages and Advantages of the Aluminum PCB?
The aluminum boards are known as a thermally conductive option. They help in keeping heat off from the important components. This is to make sure of minimal circuit damage. As a result o their high tolerance, they have the ability to handle larger levels of power in higher density circuits.
The substrates that are created from the aluminum alloys usually feature a high physical durability which reduces the breakage risk. In contrast to the other metals, the aluminum features a les environment impact as well as reasonable cost.
Furthermore, aluminum PCBs can have additional niche uses in contrast to the standard boards. Although they come at a lesser price than adding some conductors to the copper board, they are usually more expensive than the standard PCBs excluding those components.
Investment in aluminum core might not pay off properly if the application doesn’t deal with high temperatures. Also, if you want to create the flex circuit, the aluminum flex PCB could only flex into the initial position. Furthermore, the aluminum core can bend into the initial position. It bends to fit in smaller electronics. However, it will not withstand the vibration stress.
Advantages
- Low cost
- Environmentally friendly
- Heat dissipation
- Higher durability
- Lightweight
Disadvantages
- It has a high cost
- Also, the present mainstream only doe single aluminum PCB. Doing a double sided aluminum PCB is difficult
- The product will have matter easily in electrical pressure and strength
- Aluminum can have more rapid attacks from halide ions.
What is the Performance of Aluminum PCBs?
Thermal Dissipation
The usual PCB substrates, like CEM3, FR4 are known as poor thermal conductors. Furthermore, the electronic equipment heat can’t be distributed quickly. This results in high temperature electronic components failure. Also, the Aluminum substrates help in solving the problem of thermal dissipation.
Thermal Expansion
The Aluminum substrate PCB has the ability to solve the issue of thermal dissipation effectively. This alleviates the contraction and thermal expansion issues of components present on the printed circuit boards having different substances. Thus helps in improving the reliability and durability of the entire electronic equipment and machine. Particularly, the aluminum substrate has the ability to solve the issues relating to contraction, thermal expansion, and surface mount technology (SMT).
Dimensional Stability
The Aluminum substrate PCB apparently has a higher stability in contrast to the PCB’s insulating material. Anytime, it is heated from around 30 degrees centigrade to about 140 to 150 degrees centigrade, the dimensional change that happens in the aluminum substrate will be just 2.5 to 3.0%.
Other Performance
The Aluminum printed circuit board features a shielding effect, which could have an alternative ceramic substrate. Also, this aluminum substrate helps in improving the physical properties and heat resistance. It also reduces the labor and production costs.
Structure of Aluminum PCBs
The Aluminum PCBs are usually the aluminum based CCLs. Note that CCL is known as a base material for PCBs. Actually, the aluminum PCBs are similar to the FR4 PCBs. Aluminum PCBs basic structure is four layers. It is made up of the copper foil, aluminum base membrane, aluminum base layer, and a dielectric layer. Let’s take a look at each of these layers.
Copper Foil Layer: This layer is thicker compared to the usual CCLs (about 1oz to 10oz). The thicker copper layer indicates a larger capacity for carrying current.
Dielectric Layer: This Dielectric layer is the thermally conductive layer. Usually, it has a thickness that falls between 50μm and 200μm. Also, it has low thermal resistance, which makes it appropriate for the application.
Aluminum Base: Here, the next layer is the aluminum base. It is composed of the aluminum substrate. Also, it features high thermal conductivity.
Aluminum Base Membrane Layer: This aluminum base membrane is known to be selective. Also, it features a very protective role ensuring that the surface of the aluminum is safe from unwanted etching and scraping. Also, it is composed of two major types. The first is less than 120 degrees, while the other is about 250 degrees (which is the anti-high temperature).
What is the Classification of Aluminum PCBs?
Essentially, the aluminum PCBs are categorized into three.
Universal Aluminum PCB: Here the dielectric layer of aluminum PCBs is composed of a prepreg called epoxy glass fiber.
High frequency Aluminum PCB: Here, the dielectric layer of the aluminum circuit boards is made up of a prepreg called polyimide resin glass fiber.
Aluminum PCB with a high thermal conductivity: This dielectric layer is made up of epoxy resin. The resin used must have high thermal conductivity.
What are the Manufacturing Difficulties of Aluminum PCBs?
Almost all Aluminum PCBs having a similar manufacturing process are the same. In this section, we will be discussing the main manufacturing processes, as well as their problems and solutions.
Copper Etching
The Aluminum PCBs copper foil is comparatively thicker. However, once this copper foil is more than 3oz, this etching will need width compensation. If this doesn’t work in line with the design’s demand, its trace width will fall out of the tolerance after the etching. Therefore, its trace width compensation has to be accurately designed. You have to control the etching factors all through the manufacturing process.
Solder Mask Printing
As a result of the thick copper foil, the solder mask printing of the aluminum PCB comes with a difficulty. This is happening due to the too thick nature of the trace copper then that image etched would feature a large difference present between base board, trace surface and solder mask printing would be difficult.
So therefore, you make use of the two-time solder mask printing. This solder mask oil that you have used must have great quality. At times, resin filling is performed first, after this is the solder mask.
Mechanical Manufacturing
Here, the mechanical manufacturing process deals with v-scoring, molding, and mechanical drilling, etc. that is left on the internal via.
This seems to reduce the electrical strength. This is why the professional milling and electric milling cutter has to be used for the low-volume manufacturing of different products. These drilling parameters have to be adjusted to help in preventing the generation of burr. This helps mechanical manufacturing.
What are the Applications of the Aluminum PCB?
The aluminum base features a great thermal dissipation. Due to the fact that the LED generates so much heat, the LED lamp’s printed circuit board is usually aluminum substrate.
- Audio equipment: output and input amplifiers, audio amplifiers, balanced amplifiers, power amplifiers, preamplifiers, etc.
- Power supply equipment like DC-AC adapter, conditioner, stabilizer, etc.
- Communication equipment such as filter electrical circuits, high-frequency amplifiers, etc.
- Equipments for office automation like motor driver
- Office automatic equipment: motor driver and so on.
- Power modules which include rectifier bridges, solid relays, inverters, etc
- Computer such as motherboard, floppy disk drive, device for power supply
- Electronic control such as transistor base, relays, and different vital components present in a circuit
- Microwave, switches: semiconductor devices, radiator, thermal insulation, motor controller, and semiconductor devices.
- Industrial vehicles: this relates to the voltage regulator, ignition, lighting conversion system, automatic safety control system
- LED Display: This includes two modes display having an LED light source, and LED display
- Lighting: Due to the recent promotion of the energy-saving lamps, different LED lights (energy-saving) have been widely accepted by the market. This is one good reason why the aluminum substrates for the LED lights usually have different large scale applications
Conclusion
Here’s the end of our article on aluminum printed circuit boards (aluminum PCBs). Here, the significance of an insulated metal substrate cannot be overemphasized.
