Modern Automotive Circuit Boards: The Skeleton of Today's Automotive Sector
Printed Circuit Boards (PCBs) play a crucial role in the operation of modern automobiles, holding together the sensors and components that make a vehicle function. In the automotive sector, PCBs are designed and manufactured to withstand extreme environmental conditions, vibrations, and operate reliably over the long run.
Common Types of Automotive PCBs
The common types of automotive PCBs include rigid, flexible (FPC), and rigid-flex boards, each suited to different automotive applications based on mechanical and environmental demands.
Rigid PCBs
Rigid PCBs, made of FR-4 (Fiberglass epoxy), offer good mechanical strength, electrical insulation, thermal stability (with high Tg options exceeding 170°C), and flame resistance. They are widely used in general automotive electronics such as infotainment, lighting, Engine Control Units (ECUs), and sensor boards.
Flexible PCBs
Flexible PCBs, made of Polyimide (PI), provide high flexibility, thermal stability up to 400°C, chemical resistance, and high dielectric strength. They are used where bending is needed, such as in sensors, connectors, and harness interconnections in cramped or moving parts in vehicles.
Rigid-Flex PCBs
Rigid-Flex PCBs are a combination of rigid and flexible boards, offering a blend of strength and flexibility. They are employed in advanced automotive systems requiring complex shapes, vibration resistance, and weight reduction, such as advanced driver-assistance systems and electric vehicle modules.
Metal-Core PCBs
Metal-Core PCBs, consisting of an aluminum base layer, provide improved electrical insulation and thermal conductivity, making them suitable for heat transfer applications. They are used in high-power or high-temperature environments like brake and suspension controllers, LED modules, and power electronics.
Specific Applications in Automobiles
Safety Systems
Safety systems such as airbags, Electronic Stability Program (ESP), and Hill Start Assist typically use robust FR-4 rigid PCBs for reliability and cost-effectiveness.
Passenger Cars with Advanced Features
Passenger cars with advanced features, including infotainment systems and parking assistance, integrate large-area multi-layer rigid and rigid-flex PCBs for connectivity and electronic control.
Electric Vehicles (EVs)
EVs require PCBs with high dielectric breakdown strength (>40 kV/mm) for battery management, inverter, and onboard charger modules. These often employ polyimide flexible or high-performance FR-4 substrates with enhanced thermal properties.
Commercial Vehicles and Heavy-Duty Applications
Commercial vehicles and heavy-duty applications focus on ruggedized PCBs, often metal-core or thick-copper FR-4, to withstand vibration and thermal stresses.
The Future of Automotive PCBs
The growth of the PCB industry in the automotive sector is expected to increase significantly due to the focus on autonomous and electric vehicles. Manufacturers of automotive PCBs are required to be qualified with ISO/TS 16949, which is based on ISO 9001 automotive standards. PCBs also need to qualify for stringent thermal cycling test, thermal shock test, and temperature humidity test before they are taken into consideration.
The CAN bus protocol is used to ease serial communication and reduce cost and complexity in automotive systems. The evolution of PCB technology will continue to drive innovation in the automotive industry, enabling the development of safer, more efficient, and more advanced vehicles.
- The growing emphasis on autonomous and electric vehicles promises significant expansion in the PCB industry, particularly in the automotive sector, as manufacturers strive to meet stringent thermal cycling test, thermal shock test, and temperature humidity test requirements.
- To facilitate serial communication, reduce cost, and enhance the complexity of automotive systems, the CAN bus protocol is commonly used, and its application is expected to increase alongside the advancement of PCB technology in the automotive industry.
