Unveiling the choice: Why Engineers Opt for Aluminum-based PCBs in Design

In today's high-tech landscape, the escalating demands for heat dissipation in designs, spanning from LEDs to high-power circuits, are steering an innovative wave in thermal management technologies. Aluminum-based PCBs are at the forefront of this revolution, offering designers a broader scope for creativity. Not only do these PCBs efficiently transfer heat away from components, but they also excel in temperature control for projects. In comparison to equivalent glass fiber backboards, aluminum-based PCBs boast thermal dissipation efficiency often up to ten times higher, opening possibilities for designs with increased power and density. This article delves into why engineers choose aluminum-based PCBs when designing LED systems.

What is an Aluminum-based PCB?

A Printed Circuit Board (PCB) is a fundamental component in electronic devices. An aluminum-based PCB is a type of metal-clad PCB with excellent heat dissipation properties. Typically composed of three layers for single-sided boards – circuit layer (copper foil), insulation layer, and metal base layer – high-end applications may feature double-sided designs with a structure of circuit layer, insulation layer, aluminum base, insulation layer, and circuit layer. In rare cases, multilayer boards can be created by combining conventional multilayer boards with insulation layers bonded to aluminum bases.

Composition of Aluminum-based PCB

1.Circuit Layer:
The circuit layer, usually made of electrolytic copper foil, is etched to form printed circuits for device assembly and connection. When compared to traditional FR-4, aluminum-based boards, with the same thickness and line width, can carry higher currents.
2.Insulation Layer:
The insulation layer is crucial in aluminum-based PCB technology, serving functions of bonding, insulation, and thermal conduction. The insulation layer acts as the largest thermal barrier in power module structures. Better thermal conductivity of the insulation layer facilitates the diffusion of heat generated during device operation, leading to lower operating temperatures and, consequently, enhanced module performance.
3.Metal Base Layer:
The choice of metal for the base layer in an insulated metal baseboard depends on considerations such as the coefficient of thermal expansion, thermal conductivity, strength, hardness, weight, surface condition, and cost.

Structure and Characteristics of Aluminum-based PCB

While traditional PCBs use glass fiber-based boards (usually FR-4 standard boards), aluminum-based PCBs comprise an aluminum base, a high thermal conductivity dielectric layer, and a standard circuit layer. The circuit layer is essentially a thin PCB adhered to the aluminum layer. Even in LED designs, the solder mask layer is often white to enhance the light reflection of LED arrays and design efficiency. In power designs, a black solder mask layer aids in better heat dissipation.

Single-sided aluminum substrate: There is only one conductive pattern layer and insulating material plus an aluminum plate (substrate)

Double-sided circuit aluminum substrate: There are two layers of conductive graphics layer and insulating material plus aluminum plate (substrate) superimposed together

Multilayer printed aluminum-based circuit board: a printed circuit board made of three or more conductive pattern layers and insulating materials plus aluminum plates (substrates) alternately laminated and bonded together.

Principles of Aluminum-based PCB Heat Dissipation

Power devices are surface-mounted on the circuit layer, and the heat generated during device operation quickly conducts through the insulation layer to the metal base layer. Subsequently, the metal base layer transfers the heat away, achieving effective heat dissipation. Compared to traditional FR-4, aluminum-based boards minimize thermal resistance, endowing them with excellent thermal conductivity. Additionally, aluminum-based boards offer unique heat dissipation advantages, such as efficient handling of heat diffusion in circuit design, reducing module operating temperatures, extending lifespan, and enhancing power density and reliability.

High-Power Applications of Aluminum-based PCBs

Aluminum-based PCBs play a crucial role in high-power and high-heat dissipation applications, initially used in high-power switch-mode power supplies and now gaining popularity in LED applications. Typical scenarios for LED applications include traffic signal lights, general lighting, and automotive lighting. Adopting aluminum-based designs (LED PCBs) allows for a higher density of LEDs, supporting increased current while maintaining appropriate temperature ranges. Compared to traditional PCBs, aluminum-based designs enable designers to lower the safety margin for power LEDs, achieving more efficient designs. Lower LED operating temperatures correspond to prolonged lifespans, a critical factor for design reliability.

Other Applications of Aluminum-based PCB

Beyond LED applications, aluminum-based PCBs find widespread use in high-current circuits, power supplies, motor controllers, and the automotive sector. For designs requiring high-power surface-mounted ICs, aluminum-based PCBs serve as an ideal solution for thermal management. Notably, they eliminate the need for forced ventilation and additional hardware (including thermal interface materials), reducing overall design costs. In summary, any aspect of design improvement achievable through enhanced thermal conductivity and temperature control may be an applicable domain for aluminum-based PCBs.

Conclusion

In conclusion, when traditional glass fiber (FR-4) backboards fall short of meeting design requirements for heat dissipation and density, aluminum-based PCBs become a key element in solving thermal design challenges, especially in LED applications. Choosing aluminum-based PCBs in design is a prudent move for pursuing efficient heat dissipation and innovative design.



Aluminum-based PCB, metal core pcb manufacturer, aluminum core pcb,