Aluminum PCB, Construction, Working, Types & Applications

Hello, friends; I hope all of you are enjoying your life. In today’s tutorial, we will have a look at Aluminum PCB. The word PCB is the abbreviation of the printed circuit board. This circuitry is now used in almost every electronic device and engineering project. From your calculator to GPS (Global Positioning System), all consist of a printed circuit board. Construction, there are numerous types of PCB, such as single sided PCB, double-sided, Multilayer PCB, Flex PCB, Rigid PCB, and Rigid Flex PCB. In today’s post, we will look at another PCB category called Aluminum PCB.

The other name of this board is aluminum clad, metal clad printed circuit board, IMS, etc. This board consists of a thin sheet of conductive dielectric substance. The first time these printed circuit boards were invented in the year of 1970 and due to their different features and easy-to-handle capability, their use became very common in different projects. It was the first time used in amplifier Hybrid ICs. In today’s post, we will have a look at its construction, working, applications, and some other related parameters. So, let’s get started with what is Aluminum PCB.

Aluminum PCB

• Aluminum PCB is constructed by aluminum and has a high heat dissipation factor so it mostly used in lighting products like light-emitting diodes.
• This module has two sides the first side is white in color and has numerous light-emitting diodes, and the other side, aluminum is used.

• There are generally single-sided aluminum printed circuit boards comprised 3 different layers: copper foil, the second one is an insulated sheet and the third one is metal.
• But if there is are double-sided circuit board, then it has a circuitry layer, an insulating layer, an aluminum-based layer, and a circuitry layer.
• But very rarely, a multilayer circuit board is used that is constructed by the regular multiple-layer board having insulated layers and aluminum-based material.
• In the past, aluminum-based substrate was constructed with fiberglass but due to its low heat bearable capability, it was replaced with aluminum in some other applications, a substrate is still constructed with fiberglass.
• If we compare FR-4 (flame retardant) with the aluminum base material, then aluminum decreases the thermal resistance value.
• In heat transfer applications, to fulfill the needs of the manufacturing process, occasionally by decreasing the thermal resistance for the increment of heat transfer, and sometimes there is an increment in the value of thermal resistance to overturning heat transfer, the aluminum substrate has outstanding thermal conductivity, if we do its comparison with thick-film ceramic circuitry, its mechanical features are very outstanding. 

Types of Aluminum PCB

• There are many types of this circuitry board according to construction and design. The main function of all types is alike and used to reduce the high temperature produced in different circuits.

• These are some types of aluminum PCBs.
  • Flexible Aluminum PCB
  • Hybrid Aluminum PCB
  • Multilayer Aluminum PCB

Flexible Aluminum PCB

• This type of aluminum printed circuit board comprises 3 different layers first a conductive circuitry layer, flex dielectric insulation material and the third, an aluminum substrate.

• The insulation layer is constructed by the polyamide and ceramic plasters (fillers), and has a higher value thermal conductivity, permitting it to transmit heat from the circuit to the aluminum substrate, where the heat energy scatters.
• These are some advantages of this printed circuit board.

Heat Transfer:

• Due to the insulation layer and aluminum, this board has high thermal competencies. The conductive dielectric layer can transfer heat up to ten times more efficiently than fiberglass, avoiding destruction from overheating and permitting circuitry boards to tackle large values of currents.

Less weight:

• As the weight of aluminum is very less so this PCB is also exiting in less weight modules.

Durable:

• Due to their flexible behavior, this board’s operating life is longer as compared to other printed circuit boards.

Less Price:

• As there is no need for special machines for the reformation of aluminum, it is cost-effective to easily design this PCB board.

Hybrid Aluminum PCB

• In this printed circuit board, the insulating or thermal substance is processed separately before joining with the aluminum substrate.
• For this board, FR-4 flame resistance is used to construct it, having two and four layers.
• A non-thermal substance used for construction provides high stiffness and heat dissipation.
• This nonthermal attachment is referred to above using all thermal constituents since its price is less and provides effectual heat conductance over FR4 yields.
• There is no need for any heat sink to produce this PCB.

Multilayer Aluminum PCB

• Multilayer aluminum printed circuit board is mostly used in power supplies modules and has a large no of heat-conductive dielectric materials.
• Insulated metal substrate covered by a sheet of a dielectric material like epoxy and copper layer.

Construction of Aluminum PCB

• Aluminum printed circuit boards are aluminum-based CCLs (Copper-clad laminate) that are based on the material used for printed circuit boards. The structure of the aluminum printed circuit board is similar to the FR-4 flame-resistant printed circuit board.

• The basic design of the aluminum printed circuit board has 4 layers. That is a copper foil, dielectric material, layer of aluminum, and aluminum-based membrane.

Copper Foil:

• This copper foil has a larger thickness than normal CCLs (Copper-clad laminate) such as one ounce to ten ounces.
• The term thickness tells about the current-carrying capability.

Dielectric Layer:

• This layer is thermally conductive and its thickness is about fifty micrometers to two hundred micrometers. This layer provides less value of heat resistance.
• Aluminum Base: The 3^rd layer is the base that is constructed by the aluminum substrate and provides a higher value of heat conductivity.

Aluminum Membrane:

• This layer is optional it protects the aluminum from scratching and undesired corrosion.

Advantages of Aluminum PCB

• These are some important advantages of an aluminum-based printed circuit board.
• The use of aluminum for PCB construction is nonhazardous means environment-friendly and aluminum can be easily recycled. There is no need for special manufacturing tools for aluminum so its use is cost-effective.
• In any electronic circuitry, heat production causes a lot of problems so we should use a material that can easily bear heat aluminum is the best option for such circuitry.
• The operating life of aluminum is longer than the fiberglass and ceramic materials used for PCB production.

• The main feature of that makes it effective for the production of a printed circuit board is its lower weight.

Applications of Aluminum PCB

• Now we describe some practical applications of the aluminum printed circuit board.
• All types of amplifier circuits used in electronic industries consist of this board like input, output amplifiers, acoustic amplifiers, etc.
• Different power supply modules like switching regulators, analog to digital converters, etc use aluminum PCB for circuit construction.
• Your computer motherboard, floppy disk, also consists of this circuit board.
• Different inverters, relays, and rectifiers also comprise this circuit board.
• Different types of light-emitting diodes also comprise an aluminum circuit board.

Aluminum Pcb vs fr4

1. Aluminum provides good thermal conductivity about 6000 times higher than FR4. These features of aluminum board dissipate heat and best to use LED lights and a power converter. FR4 has a low heating dissipation factor so not used for high-temperature circuits.
2. FR4 has a high value of  Coefficient of Thermal Expansion (CTE) about 12-24 ppm/°C and aluminum has 24 ppm/°C
3. FR4 board can be made in single, double, and multilayer designs while aluminum PCBs are made in tri-layer designs.
4. ALumiunm boards provide high mechanical strength and have rigidity as compared to FR4 sine uses metallic base material.
5. FR4 boards come with high thickness but aluminum has limited thickness about 0.8mm to 4mm thick.

Manufacturing Difficulties of Aluminum PCB

1. The thickness of copper foil used in the aluminum board has a high thickness. If copper foil is higher than 3oz then needed more etching width. That causes problems for trace width that not be changed according to design.
2. The thick copper foil also causes issues with the application of solder masks on board. If trace copper has high thickness then the design etched will have high difference traces and solder mask printing will be difficult.
3.  use electrical milling and milling cutterthat help to avoid electrical strength issues. That makes mechanical manufacturing effective and comes with mechanical drilling, molding v-scoring, etc.

Aluminum PCB Applications

• It is used for making circuits of balanced amplifiers, audio amplifiers, and other amplifier circuits.
• It is also used for conditioners, and DC to AC adapter circuits.
• It is used to make communication device circuits such as high-frequency amplifiers.
• It makes motor driver circuits.
• It makes power supply circuits such as solid relay rectifier circuits.
• It makes relay and other control circuits
• LED display also made with use of aluminum PCB board

Related Posts

• Aluminum PCB (Printed Circuit Board)
• Multilayer PCB (Printed Circuit Board)
• Rigid PCB (Printed Circuit Board)
• Flex PCB (Printed Circuit Board)
• High Frequency PCB (Printed Circuit Board)
• Single Sided PCB (Printed Circuit Board)
• Rigid-Flex PCB (Printed Circuit Board)
• Double-sided PCB (Printed Circuit Board)

Faqs

This is the complete post on the aluminum PCB I have mentioned every parameter related to his PCB board. If you have any queries about this module, ask in comments. Thanks for reading. See you in the next tutorial.