The key points of heat dissipation design for aluminum-based PCB manufacturing mainly include the following aspects:
Material selection:
Aluminum substrate: The aluminum substrate is a core component of aluminum-based PCBS, featuring excellent thermal conductivity and mechanical processing performance. Select the appropriate aluminum substrate material and ensure its good thermal conductivity to enhance the heat dissipation effect.
Copper layer thickness: Increasing the copper layer thickness of a PCB can reduce resistance, decrease heat generation, and simultaneously enhance thermal conductivity. For high-power circuits, a thicker copper layer can be considered.
Layout optimization
Component layout: Arrange the heat-generating components reasonably on the PCB to avoid concentrating them in one area, thereby reducing heat accumulation. High-power and high-heat-generating components should be placed at the edge of the circuit board or in well-ventilated positions to facilitate the dissipation of heat more easily.
Spacing setting: Leave sufficient spacing between the heating elements to ensure that the heat can be effectively dissipated. At the same time, a certain distance should be maintained between the heat-generating element and the sensitive element to prevent heat from affecting the sensitive element.
Heat dissipation structure design
Heat dissipation holes and grooves: Design heat dissipation holes or grooves on the PCB to increase the heat exchange area between the circuit board and the surrounding environment and promote heat dissipation. The size and distribution density of the heat dissipation holes should be optimized based on the heat generation power and layout of the components.
Heat sink: For some high-power components, heat sinks can be installed on their surfaces to increase the heat dissipation area and improve the heat dissipation efficiency. The material of heat sinks is generally aluminum alloy or copper alloy, which has good thermal conductivity and heat dissipation.
Thermal resistance control
Thermal resistance optimization: The thermal resistance of aluminum-based PCBS mainly consists of internal device thermal resistance, interface thermal resistance, dielectric layer thermal resistance, metal substrate thermal resistance, and heat dissipation path thermal resistance, etc. By optimizing these thermal resistances, the overall thermal resistance can be reduced and the heat dissipation efficiency can be improved.
Thermal conductive materials: High thermal conductive interface materials (such as thermal conductive adhesives, thermal conductive pads, etc.) are used between the heating element and the heat sink to reduce thermal resistance and improve thermal conduction efficiency.
Simulation and Analysis
Thermal simulation: Use thermal simulation software for thermal analysis, identify hotspots and optimize the design. Through simulation analysis, the temperature distribution of the PCB under different working conditions can be predicted, providing a basis for heat dissipation design.
Design verification: After the design is completed, conduct thorough circuit simulation and thermal simulation analysis to ensure the reliability and performance of the design.
Manufacturing process:
Size matching: Ensure that the size of the aluminum substrate matches that of the circuit board to avoid any size mismatch.
Electrical insulation: The electrical insulation performance of aluminum substrates is relatively poor. Therefore, during the design process, it is necessary to pay attention to avoiding contact between wires and aluminum substrates to prevent short circuits.
