Overview of Multilayer Aluminum-based PCB Technology: Principles, Advantages and Application Expansion

This article focuses on the technology of multilayer aluminum-based printed circuit boards (PCBs), analyzes its structural principles, elaborates on its advantages by comparing with traditional PCBs, explores its applications in multiple fields, and analyzes the existing challenges and development trends. It aims to provide in-depth technical references for industry insiders and facilitate relevant work.

I. Introduction

With the rapid development of electronic technology, equipment is moving towards miniaturization, high performance, and high power density. Traditional PCBs are gradually showing limitations in heat dissipation and power carrying capacity. Multilayer aluminum-based PCBs have emerged at the right time, combining the advantages of multilayer wiring and aluminum-based heat dissipation, becoming a research hotspot in the field of electronic circuits and laying a solid foundation for high-performance electronic applications.

II. Structural Principles

1. Basic Structure

A multilayer aluminum-based PCB consists of an aluminum base layer, an insulation layer, and a conductive layer (including signal and power layers). The aluminum base layer is made of high-purity aluminum plates with excellent thermal conductivity and serves as the main force for heat dissipation. The insulation layer is made of materials such as epoxy resin and polyimide. Its thickness and dielectric properties are determined according to circuit design and play an electrical isolation role. The conductive layer creates circuit patterns through etching and electroplating. Electrical connections between layers are achieved through through holes, blind holes, or buried holes, building an efficient multilayer circuit.

2. Interlayer Connection Technology

Interlayer connection is extremely crucial for multilayer aluminum-based PCBs. Through holes penetrate the PCB for conventional electrical connections. In high-frequency and high-speed scenarios, blind holes connect the surface layer and the inner layer, and buried holes connect the inner layers, which can reduce signal transmission paths and parasitic parameters, ensuring signal integrity and speeding up transmission. When making connections, it is necessary to strictly control the diameter, depth, and electroplating quality of the holes, taking both electrical and heat dissipation properties into account.

III. Advantages

1. Excellent Heat Dissipation

The thermal conductivity of aluminum-based materials reaches 200 - 400 W/(m・K), far exceeding that of FR-4 substrates (0.2 - 0.5 W/(m・K)). Multilayer aluminum-based PCBs can quickly transfer the heat of heating elements to the aluminum base layer through the conductive layer and then dissipate it to the surroundings. For example, in LED lighting, it can reduce the junction temperature of LEDs, extend their lifespan, and improve lighting stability.

2. High Power Carrying Capacity

Excellent heat dissipation endows it with high power carrying capacity. In power electronic equipment, high-power components in frequency converters and inverters generate a large amount of heat. This PCB provides both electrical and heat dissipation guarantees for them, maintaining the stable operation of the equipment at high power and improving the power processing and efficiency of the system.

3. Good Mechanical Stability

The aluminum base layer gives multilayer aluminum-based PCBs high mechanical strength and strong stability, making them resistant to deformation and warping, suitable for complex mechanical and assembly environments. In automotive electronics, in the face of vehicle vibration and impact, it can ensure the normal operation of the electronic system, enhancing reliability and durability.

4. Strong Electromagnetic Shielding

The aluminum base layer has inherent electromagnetic shielding capabilities and serves as a shielding layer, reducing internal and external electromagnetic interference. It is of great significance in fields with high requirements for electromagnetic compatibility, such as communication base stations and radar systems, helping to improve the electromagnetic compatibility and anti-interference level of the system.

IV. Application Fields

1. Automotive Electronics

With the upgrading of automotive electronics, systems such as engine control, battery management, and autonomous driving require high-performance PCBs. Multilayer aluminum-based PCBs solve the heat dissipation problems of high-power components. For example, in the control of the drive motor of an electric vehicle, it can carry high voltage and large current, dissipate heat in a timely manner, and ensure the efficient and precise operation of the motor.

2. LED Lighting

LED lighting is widely used due to its energy-saving and long lifespan features. Multilayer aluminum-based PCBs are an ideal substrate. They can quickly dissipate heat, keep the temperature of LED chips appropriate, improve luminous efficiency and color rendering, and reduce light decay. They are active in various lighting and backlight source scenarios, promoting the popularization of the technology.

3. Communication Base Stations

In the 5G era, the power and signal processing requirements of base stations have increased. Multilayer aluminum-based PCBs are used in radio frequency and power amplification modules, conforming to high-frequency and high-speed transmission, efficiently dissipating heat, improving the reliability and performance of the base station, reducing signal distortion, and widening the communication coverage.

4. Power Electronics

For high-power power conversion and control equipment such as industrial frequency converters, solar inverters, and UPS, multilayer aluminum-based PCBs are suitable for high-voltage and large-current working conditions, ensuring electrical and heat dissipation performance. For example, in the inverter of a solar power generation system, it enables efficient operation and improves the overall efficiency of the system.

V. Challenges and Trends

1. Challenges

(1) Cost and Processing: High-quality aluminum base and insulation materials are expensive, driving up manufacturing costs. The high hardness of aluminum base makes drilling and etching difficult, easily leading to tool wear and loss of precision, affecting production efficiency and product quality.

(2) Signal and Electromagnetic Compatibility: Although there is an aluminum base layer for shielding during high-frequency and high-speed transmission, problems such as transmission line effects and interlayer crosstalk are complex. More refined design and simulation technologies are needed to optimize signal integrity and electromagnetic compatibility.

(3) Technical Integration: In emerging fields such as flexible electronics and wearable devices, the compatibility between the rigidity of aluminum base and flexible materials is poor. It is a challenge to achieve seamless integration of different materials and technologies.

2. Trends

(1) Material Innovation: Research and develop new aluminum-based and insulation materials to reduce costs and improve performance, develop aluminum alloys with high thermal conductivity and easy processing, and insulation materials with low dielectric constant and high heat resistance.

(2) Refined Design: Rely on CAD and electromagnetic simulation software for precise modeling and analysis, pre-research and optimize signal, electromagnetic, and heat dissipation properties. Combined with artificial intelligence and big data, achieve intelligent design decisions and reduce the number of iterations.

(3) Integrated Development: Explore the integration path with emerging technologies, develop flexible aluminum-based PCBs to meet the needs of foldable equipment; in the fields of the Internet of Things and intelligent sensing, integrate sensors and microprocessors to create multifunctional PCB modules, helping equipment to be miniaturized and high-performance.

VI. Conclusion

Multilayer aluminum-based PCB technology plays a crucial and irreplaceable role in multiple fields with its unique structure and excellent performance. Although it currently faces challenges in materials, processing, and signals, with technological innovation, it has broad prospects in material optimization, refined design, and technology integration. In-depth research and promotion of this technology will effectively promote the upgrading of the electronics industry and empower the development of modern electronic equipment towards high performance, high reliability, and miniaturization.