There are several types of aluminum PCBs which are used in many applications based on their construction and design. However, the primary purpose of all the aluminum PCBs is almost the same; providing heat dissipation solutions for the applications involving high temperatures.
The following are the main types of aluminum PCB.
Flexible Aluminum PCB Board
Firstly, Flexible aluminum PCB is a new flexible dielectric developed in the development of aluminum products. It is also a kind of flexible circuit board. Because of the combination of polyimide resin and ceramic filter, it has high flexibility, thermal efficiency, and excellent electrical insulation. When used in aluminum PCB products, the expensive cables and connectors no longer need to be used.
Flexible circuit boards have unparalleled flexibility, so flexible aluminum PCB can be arbitrarily folded, twisted, or formed in any other desired form.
However, it should be noted that once a specific shape is created, it can no longer be changed like other conventional flexible circuit boards or deform.
Hybrid Aluminum PCB Board
In hybrid aluminum construction, nonthermal material is processed and refined separately before it is applied to the thermal materials with aluminum base.
The most common practice is developing a two-layer or four-layer structure which comprises of FR4 material.
A nonthermal material that is bonded with thermal material and the aluminum base provides rigidity and helps in the dissipation of heat.
This nonthermal bonding is preferred over using all thermal materials because it features less cost and encompasses efficient thermal conductance over regular FR4 products.
No heat sinks or assembly steps are required for the development of this product.
Through-hole components can be easily adjusted using component windows on the aluminum base.
This helps in passing the cables and connectors through the substrate. Also, the seal created by solder fillet eliminates the need for costly adapters
Classification of Aluminum PCB
Aluminum PCBs are mainly divided into three categories.
- Universal Aluminum PCB: the dielectric layer used here is made up of epoxy glass fiber pre-preg.
- High Thermal-Conductive Aluminum PCB: the dielectric layer is made up of epoxy resin. The resin used must have high thermal conductivity.
- High-frequency Aluminum PCB: the dielectric layer is composed of polyolefin or polyimide resin glass fiber pre-preg.
Multilayer Aluminum PCB Board
Multilayer Aluminum PCBs are ubiquitous in power supply products and come with multiple layers of thermally conductive dielectrics.
These materials are beneficial when they are combined with one or more layers of circuitry in which thermally conductive dielectric is buried between the sheets with the help of blind vias, which also act as a signal or thermal vias.
Single-layer construction of these designs is not very active; however, when they come with more elaborate designs, they provide an ideal solution for many applications involving heat dissipation.
Through-Hole Aluminum PCB
When it comes to most complex constructions, a single layer of aluminum is back-filled and pre-drilled with before applying lamination, forming a Core of a multilayer construction.
Thermal bonding materials are then used for laminating the thermal materials on both sides of the aluminum.
Once lamination is done, drilling is applied to the assembly.
To maintain proper electrical insulation, the plated through holes created as the result of drilling must pass through aluminum clearances.
