Aluminum Circuit Boards: The Core of Heat Dissipation

This composite material, consisting of a circuit layer, an insulating layer, and an aluminum base layer, has become a core component in fields such as LED lighting, automotive electronics, and power conversion. When heat generated by power devices rapidly conducts through the insulating layer to the aluminum base layer, the efficiency of the entire heat dissipation process is fundamentally enhanced.

Heat Dissipation System

As electronic products evolve toward higher power density and greater integration, traditional printed circuit board materials struggle to meet increasingly demanding thermal challenges. Conventional FR-4 and CEM-3 materials are poor thermal conductors, prone to causing localized overheating and component failure.

The advent of aluminum-based circuit boards has fundamentally transformed this landscape. This metal-clad laminate comprises three critical layers: the circuit layer (copper foil), the insulating layer, and the metal substrate (aluminum base). This unique sandwich structure enables efficient heat transfer from heat-generating components across the entire board.

The core breakthrough lies in the insulating layer—a barrier to electrical current yet a thermal bridge. High-performance insulating layers typically consist of specialty ceramic-filled polymers, achieving minimal thermal resistance while maintaining superior electrical insulation.

Structural Analysis

The exceptional performance of aluminum-based circuit boards stems from their sophisticated three-layer design. Each layer serves a specific function, collectively forming an efficient thermal management system.

The circuit layer (copper foil), typically 35μm to 280μm thick, is etched to create intricate circuit patterns. This layer not only conducts electrical current but directly influences current-carrying capacity. Thicker copper foil supports higher current loads while reducing resistance-induced heating.

The insulating layer represents the core technology of the entire structure. Despite its minimal thickness of 0.003 to 0.006 inches (approximately 76 to 152 microns), it fulfills dual roles in insulation and thermal conductivity. It must exhibit excellent thermal conductivity while maintaining high dielectric strength.

The metal substrate serves as the ultimate heat carrier for aluminum-based circuit boards, typically constructed from aluminum alloys such as 6061, 5052, or 1060. This layer provides structural support while uniformly distributing heat across the entire board surface through its high thermal conductivity, or transferring it to external heat dissipation structures.

Technical Parameters and Performance Specifications

The performance of aluminum-based circuit boards can be quantitatively evaluated through multiple technical parameters, which directly determine their performance in practical applications. The following are the primary technical specifications for aluminum-based circuit boards:

In addition to the aforementioned fundamental parameters, aluminum-based circuit boards also exhibit outstanding dielectric properties (dielectric constant ≤5.0, dielectric loss ≤0.05), making them particularly suitable for high-frequency applications. They provide a stable operating environment for devices such as RF amplifiers and antennas.

Production Process and Precision

The manufacturing process of aluminum-based circuit boards integrates precision machining with chemical treatment techniques, with each step directly impacting the final product's performance. The primary production flow is as follows:

Cutting and drilling mark the starting point of the manufacturing process, requiring large-sized raw materials to be cut to production dimensions and undergo positioning drilling. Modern production lines achieve ultra-high precision of ±0.01 millimeters, ensuring accurate circuit pattern alignment.

Circuit formation transfers the designed circuit patterns onto copper foil through dry/wet film imaging and etching processes. During this step, acidic or alkaline etching solutions remove excess copper foil, leaving precise circuit patterns.

Insulation layer processing is a critical technical phase. Techniques like roller lamination and temperature gradient control ensure uniformity and reliability of the insulation layer. An excellent insulation layer must possess thermal aging resistance and withstand mechanical and thermal stresses in long-term operating environments.

During surface treatment and solder mask application, screen printing technology coats the circuit board with a solder mask layer. This protects areas not requiring soldering, preventing short circuits. Simultaneously, a character layer is added to mark component locations and circuit information.

Application Landscape

Aluminum-based circuit boards have penetrated every critical sector of the modern electronics industry due to their unique thermal management advantages:

In LED lighting, they serve as indispensable core components. With the widespread adoption of energy-efficient lighting, aluminum-based circuit boards are extensively used in LED lamps, providing a stable and reliable heat dissipation platform for high-brightness LED chips. In fact, nearly half of all LED lighting fixtures nationwide utilize aluminum-based copper-clad laminates for their core circuit boards.

The power supply equipment sector represents a major application scenario for aluminum-based circuit boards, encompassing switch regulators, DC/AC converters, SW regulators, and similar devices. These components often generate significant heat, where efficient thermal dissipation directly impacts conversion efficiency and reliability.

In automotive electronics, aluminum-based circuit boards deliver exceptional thermal performance across applications ranging from electronic regulators and igniters to power controllers. Given the demanding environments where automotive electronics must operate reliably over extended periods, the boards' durability and longevity represent key advantages.

Communication electronics also extensively utilize aluminum-based circuit boards, particularly in applications like high-frequency amplifiers, filters, and transmitter circuits where both heat dissipation and signal integrity must be considered. The low dielectric loss characteristics of aluminum-based circuit boards make them especially suitable for RF and microwave applications.

Industrial automation, medical equipment, and consumer electronics represent further significant application areas for aluminum-based circuit boards. They are found in motor drivers, medical diagnostic devices, audio amplifiers, and similar fields.

Development Trends

With the continuous evolution of electronic technology, the aluminum-based circuit board industry is advancing toward higher performance, greater environmental sustainability, and increased intelligence.

The ongoing enhancement of thermal management capabilities remains a core focus for industry development. Emerging new insulating materials and structural designs are elevating thermal conductivity from the current range of 1.0–2.0 W/(m·K) to higher levels. Researchers are exploring novel substrate materials like silicon carbide and aluminum nitride to further enhance heat dissipation capabilities.

Environmental sustainability has become a critical industry consideration. While aluminum-based circuit boards already comply with RoHS requirements, the sector continues to pursue greener manufacturing processes and recyclable materials. Concurrently, carbon neutrality goals are driving companies to optimize energy usage and reduce carbon emissions.

Intelligent and automated production will further elevate product quality and manufacturing efficiency. Ningxia Jinhang New Materials' digital workshop has achieved ultra-high precision production at ±0.01 millimeters. This smart manufacturing model will be promoted across the industry to ensure product consistency and reliability.

With the rapid development of 5G communications, new energy vehicles, and IoT devices, market demand for aluminum-based circuit boards will continue to grow. By 2030, the global aluminum-based PCB market is projected to expand further, presenting new development opportunities for industry participants.

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Here'e the PCB via filing capabilities at PCBONLINEL:

• Micriavia filling with copper: laser via size 0.1-0.125mm, priority 0.1mm
• Finished hole size for via-in-pad filling with resin: 0.1-0.9mm (drill size 0.15-1.0mm), 0.3-0.55mm normal (drill size 0.4-0.65mm)
• Max aspect ratio for via-in-pad filling with resin PCB - 12: 1
• Min resin plugged PCB thickness: 0.2mm
• Max via-filling ith resin PCB thickness: 3.2mm
• Making different hole sizes with via filling in one board: Yes
• Via filling with copper/silver: Yes

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Conclusion

Via filling is used for creating stacked vias in HDI PCB fabrication, BGA/CSP/QFN IC packaging, and filling PCB via-in-pad with resin during multilayer PCB fabrication. If you need one-stop electronics manufacturing for your HDI PCBA project, contact the one-stop advanced PCB manufacturer PCBONLINE for high-quality PCBA and box-build solutions tailored to your project's needs.