Description
Data Sheet

1. Overview of Aluminum PCB

Name: 2 layer aluminum PCB
Brand: PCB Printed Circuit Board and PCBA manufacturing
Availability: InStock
Rating: 5 (1 reviews)

Aluminum Base PCB (Aluminum PCB) is a key category of Metal-Based PCB, characterized by excellent heat dissipation performance. Structurally, single-layer aluminum PCB is composed of three functional layers: circuit layer, insulation layer, and aluminum base layer. In contrast, double-layer aluminum PCB has a more complex structure, consisting of circuit layer, insulation layer, aluminum base layer, insulation layer, and circuit layer in sequence.

Aluminum PCB base material features high thermal conductivity and is compatible with conventional machining processes such as drilling, punching, and cutting. The aluminum base layer endows the product with outstanding heat dissipation capability, while the insulating dielectric layer provides high-strength electrical insulation performance. During operation, heat generated by surface-mounted devices (SMD) on the PCB is transferred to the aluminum base layer through the insulation layer, and then dissipated outward by the aluminum base layer, thereby realizing effective heat dissipation of the devices. However, due to the inherent conductivity of aluminum, aluminum PCB cannot achieve inter-layer interconnection, which limits its application scope in some complex circuit scenarios.

2. Technical Pain Points of Traditional Double-Layer Aluminum PCB

In existing double-layer aluminum PCB manufacturing, traditional resin is commonly used to fill large holes to achieve inter-layer interconnection. This process has obvious drawbacks: first, traditional resin filling of large holes is prone to bubble generation, and cracks are likely to occur under high-temperature conditions, resulting in extremely low product yield; second, the thermal conductivity of traditional epoxy resin is only 0.2W/(m·K), which can no longer meet the increasing heat dissipation requirements of aluminum substrates. In addition, the heat dissipation coefficient at the hole position and between layers of aluminum PCBs manufactured by this method is inconsistent, failing to meet the product quality standards.

3. Structure of Double-Layer Aluminum PCB

Double-layer aluminum PCB is typically composed of five layers: circuit layer, insulation layer, aluminum base layer, insulation layer, and circuit layer. As a type of metal core circuit board, it retains excellent heat dissipation performance. The board is wired on both sides, and to realize the electrical connection between the two layers of wires, a reasonable interconnection structure is required.

3.1 Circuit Layer of Double-Layer Aluminum PCB

The circuit layer is made of copper foil, which serves as the conductive medium for the circuit, ensuring the normal transmission of electrical signals.

3.2 Insulation Layer of Double-Layer Aluminum PCB

The insulation layer is made of thermal insulation materials, and its thermal resistance directly determines the efficiency of heat transfer from LEDs (or other high-heat devices) to the aluminum base layer. The performance of the insulation layer is a key factor affecting the overall heat dissipation effect of the aluminum PCB.

3.3 Aluminum Base Layer of Double-Layer Aluminum PCB

The main functions of the aluminum base layer are twofold: first, to transfer the heat transmitted from the insulation layer to the circuit layer (realizing uniform heat distribution); second, to provide mechanical support for the entire PCB, facilitating installation and fixing.

4. Misunderstanding About Aluminum PCB Thermal Conductivity

There is a common misunderstanding that the thermal conductivity of aluminum PCB is related to the thickness of the aluminum base layer. In fact, to improve the thermal conductivity of aluminum PCB, the key lies in optimizing the performance of the insulation material and reducing its thermal resistance. Reducing the thermal resistance of insulation materials is not a simple process, as it is affected by both material composition and manufacturing process parameters.

5. Via Hole Function of Double-Layer Aluminum PCB

Via holes are small holes on the PCB that are filled or plated with metal, used to realize the electrical connection between the wires on both sides of the board. Compared with single-layer aluminum PCB, double-layer aluminum PCB has twice the wiring area and solves the problem of wiring interleaving in single-layer aluminum PCB (wires can be routed to the other side through via holes). Therefore, it is more suitable for circuits with higher complexity than single-layer aluminum PCB.

6. Selection Basis of Aluminum as PCB Metal Base Material

The structure of aluminum PCB mainly includes three layers: copper foil, insulation layer, and aluminum base layer. Many users will ask: since there is an insulation layer, can other metal materials be used instead of aluminum for the metal base layer, such as copper PCB, stainless steel PCB, iron-based PCB, silicon steel PCB, etc.?

In the selection of metal base materials for PCB, in addition to thermal performance, factors such as thermal expansion coefficient, thermal conductivity, mechanical strength, hardness, weight, surface condition, and cost must be comprehensively considered. From the perspective of cost and technical performance balance, aluminum sheets are the ideal choice. Common aluminum sheet models for aluminum PCB include 6061, 5052, 1060, etc. If the application requires higher thermal conductivity, mechanical performance, electrical performance, or other special requirements, metal materials such as copper, stainless steel, iron, and silicon steel can also be used to manufacture metal-based PCB.

7. Core Features of Aluminum PCB

Compatible with Surface Mount Technology (SMT), and has excellent thermal performance in circuit design, ensuring stable operation of high-heat devices.
Effectively reduces the operating temperature of devices, improves product power density and reliability, and extends the service life of electronic products.
Helps reduce the overall volume of electronic products, as well as hardware and assembly costs, realizing miniaturization and cost optimization.
Can replace ceramic substrates, with better mechanical durability and impact resistance, adapting to more complex application environments.

8. Differences Between Aluminum PCB and FR4 PCB

Aluminum PCB and FR4 PCB are both important types of PCB, but there are obvious differences in material, performance, and application scenarios:

From the category perspective, PCB is a general term, while aluminum PCB is a special type of PCB, belonging to metal core PCB, which is named for its aluminum-based core material and excellent heat dissipation performance. At present, the mainstream PCB in the market is FR4 PCB; aluminum PCB is mainly single-layer and double-layer, with a small number of multi-layer products.

In terms of material, the core material of aluminum PCB is aluminum sheet, while the core material of FR4 PCB is FR4 substrate. The insulation layer (PP material) of aluminum PCB is special, which endows it with excellent heat dissipation performance, but its cost is also higher than that of FR4 PCB.

In terms of performance, the heat dissipation performance of aluminum PCB (metal core PCB) is significantly better than that of FR4 PCB, and the thermal conductivity of the two is quite different. In terms of cost, aluminum PCB is generally more expensive than FR4 PCB due to its special material and manufacturing process.

9. Manufacturing Process of Aluminum PCB

The standard manufacturing process of aluminum PCB is as follows: Cutting → Drilling → Dry Film Optical Imaging → Board Inspection → Etching → Corrosion Inspection → Solder Mask (Green Oil) → Silkscreen (Character) → Solder Mask Inspection → Tin Spraying → Aluminum Base Surface Treatment → Punching → Final Inspection → Packaging → Shipment.

9.1 Key Process Details

1. Cutting

Strengthen incoming material inspection; aluminum substrates with surface protective film must be used.
No baking is required after cutting.
Operate with care to protect the surface protective film of the aluminum PCB from scratches.

2. Drilling

Drilling parameters are consistent with those of FR4 PCB.
Drill with the copper sheet facing upward to ensure drilling accuracy and avoid damage to the aluminum base layer.

3. Dry Film Process

Incoming inspection: Before grinding, check the protective film on the aluminum base surface; if damaged, firmly paste blue glue for protection before pretreatment, and grind the board only after re-inspection is qualified.
Board grinding: Only treat the copper surface, without damaging the aluminum base layer and its protective film.
Coating: Both the copper surface and aluminum base surface must be coated; the interval between board grinding and coating shall be controlled within 1 minute, and the coating temperature shall be kept stable.
Lamination: Ensure lamination accuracy to avoid deviation affecting circuit pattern.
Exposure: Use an exposure ruler to control the exposure effect, with residual glue in 7~9 grids as the standard.
Development: Control the pressure at 20~35psi and the speed at 2.0~2.6m/min; all operators must wear gloves to avoid scratching the protective film and aluminum base surface.

4. FQC Inspection

The circuit surface must be fully inspected in accordance with MI (Manufacturing Instruction) requirements.
The aluminum base surface must also be inspected to ensure that the dry film on the aluminum base surface is free of peeling and damage.

10. Manufacturing Precautions for Aluminum PCB

Strictly standardize the operation process in the production process to avoid losses and wastes caused by operational errors.
The surface of aluminum PCB has poor wear resistance; operators in each process must wear gloves and handle the board gently to avoid scratches on the board surface and aluminum base layer.
In case of discontinuous production, strengthen equipment maintenance to ensure the cleanliness of the conveyor and water tank, so as to guarantee the stability of subsequent operations and production efficiency.

11. Application Scenarios of Aluminum PCB

Due to its excellent heat dissipation performance, good machinability, dimensional stability, and reliable electrical performance, aluminum PCB is widely used in fields such as LED lighting, hybrid integrated circuits, automotive electronics, office automation equipment, high-power electrical equipment, and power supply equipment.

As a professional PCB manufacturer, Maxipcb has been committed to the R&D and production of high-quality aluminum PCB. With stable product quality and reasonable pricing, Maxipcb has won wide recognition and praise from global customers, and is moving towards becoming a well-known brand in the PCB industry.

Model: 2 layer aluminum PCB

Material: aluminum PCB material

Layer: 2 Layer

Color: White/Black

Finished Thickness: 1.2mm

Copper Thickness: 1OZ

Surface Treatment: Lead-free HASL

Thermal Conductivity: 2.0w/m.k

Special Process: The 2layer aluminum PCB needs to be made according to 4 layer PCB

Application: High end LED desk lamp

2 layer aluminum PCB

Description

Data Sheet