Aluminum PCB is the most common type of metal core circuit boards. In terms of number of layers, aluminum PCBs are available in different types. These are single side, double side, and multilayer. Our major focus in this article is the single side aluminum PCB.
What is a Single Side Aluminum PCB?
A single side aluminum PCB comprises a metal base, IC components, solder mask, and dielectric copper circuit layer. Also, the prepreg dielectric offers heat transfer from the components and the foil to the base plate. The aluminum plate provides mechanical integrity to the single side substrate.
The single side aluminum PCB can be integrated with surface mount and wire components. The aluminum base offers much lower cost than ceramic substrates. A single side PCB comprises one conductive copper layer. All electronic components of a single side aluminum PCB are on one side of the circuit board.
The electronic components and conductive copper are all mounted on a side of the PCB. There is only a conductive layer in this PCB. A single side aluminum PCB is a great option when an application requires thermal conductivity. Also, this PCB keeps away heat from vital components. This helps to ensure less circuit damage.
Structure of Single Sided Aluminum Circuit Board
Single side aluminum PCB comprises the copper foil, dielectric, the aluminum base, and aluminum base membrane layer.
This is the circuit copper layer. It is thicker than CCL. Also, this layer helps to realize the connection and assembly of devices. The aluminum substrate features a higher current compared to traditional FR4.
The insulating layer is the back bone of the aluminum substrate. It acts as an insulator and heat conductor. Also, the insulating layer is the biggest thermal hindrance in the power module structure. When the insulating layer features more thermal conductivity, it enhances heat dissipation during the operation of the device.
The aluminum base is the third layer of the single side aluminum. This layer features a very high thermal conductivity.
Aluminum base membrane layer
The aluminum base membrane layer serves as a shield to the surface. It protects the PCB surface from unwanted etching and scraping.
Capabilities of a Single Side Aluminum PCB
A single side aluminum PCB offers great performance when used in electronic devices. This circuit board features several capabilities which include:
Aluminum PCB features exceptional thermal expansion. Therefore, this PCB offers solutions to thermal dissipation problems. This capability helps to improve the reliability and durability of electronic equipments. Furthermore, a single side aluminum PCB can solve SMT problems
Exceptional dimensional stability
Aluminum OCBs feature higher stability than insulating material. Also, aluminum substrate maintains 2.5 t0 3.0% dimensional change when heated.
PCB substrates like CEM3 and FR4 are poor thermal conductors. Lack of heat dissipation can result in failure of electronic components. Aluminum substrates are capable of solving heat dissipation problems.
Benefits of Single Side Aluminum PCB
Low manufacturing and production cost
The production of single side aluminum requires low cost. This circuit board doesn’t require much materials. Furthermore, aluminum is a low cost material.
Ideal for simple designs
Single side aluminum boards are suitable for simple designs.
It is lightweight
Aluminum is a very lightweight material. Also, this material adds resilience and strength without adding extra weight to the circuit board.
One of the benefits of aluminum circuit board is its environmental friendliness. Aluminum is safe for the environment. Furthermore, aluminum conserves energy since it is easy to assemble. Also, aluminum is easy to recycle.
Applications of Single Side Aluminum PCB
Aluminum boards help to enhance the performance of electronic devices. Also, the low thermal impedance of the dielectric layer offers more benefits than other PCB insulators. Also, the low cost aluminum and its excellent durability are some of the reasons single side aluminum PCBs are widely used in applications.
Aluminum boards are ideal for use in LED applications. This is because aluminum as a material offers the lowest possible temperatures while offering maximum illumination.
Thermal clad dielectric offers the electrical isolation required to meet safety test requirements. Also, aluminum PCBs are widely used for solid state relays.
Aluminum circuit boards provide various thermal performances which is works for mechanical fasteners.
The automotive industry relies on aluminum circuit boards. This is because aluminum boards offer long term reliability when used in high operating temperatures. You will find aluminum boards in automotive lighting system components.
Aluminum boards are commonly found in interior building lights, camping gears, and landscape lighting. Also, there are ideal for use in computer devices like motherboard, floppy disk drive, and more.
Manufacturing challenges of Single Side Aluminum PCB
Aluminum PCB features copper foil that is comparatively thicker. Etching will need width compensation if the copper foil is more than 3oz. Also, the trace width might be out of tolerance if it is not based on the demand of the design. Therefore, it is crucial to design the trace width compensation accurately. Furthermore, during the manufacturing process, ensure you control etching factors.
This involves V-scoring, molding, and mechanical drilling. Also, this process minimizes electrical strength. As a result, the professional milling cutter and electrical milling is ideal for low-volume manufacturing. Also, you should adjust the drilling parameters to prevent the generation of burr. This will also help the mechanical manufacturing process.
Solder mask printing
Since the copper foil in aluminum boards is thick, solder mask printing is difficult. When trace copper is very thick, the image etched will have a huge difference between the base board and trace surface. As a result of this, a two-time solder mask printing is usually integrated. Also, the solder mask oil should have great quality.
Aluminum boards are ideal for several applications due to their heat dissipation properties. Also, these properties of these boards enable them to perform well in high performance applications. Single side aluminum boards are ideal for use in power converting and LED electronics. Also, single side aluminum PCB tends to have more use cases than single side standard PCBs.