Introduction of Performance Attributes of Automotive PCB

Posted on 2020-07-15

Learn More About the Performance Attributes of Automotive PCBs

Automotive PCB quality insurance requirements

Automotive PCB manufacturers should comply with ISO9001 regulations. PCB Cart fully complies with ISO9001:2008 quality management system and is committed to complying with the strictest manufacturing and assembly standards.

ISO/TS16949 is a set of technical regulations for the global automotive industry. Based on ISO9001, coupled with the special needs of the automotive industry, we pay more attention to defect prevention and reduce quality fluctuations and waste in the auto parts supply chain.

When implementing ISO/TS16949, special attention must be paid to the five main key tools: PPAP (Production Part Approval Procedure), which regulates products to be approved by customers after mass production or modification. APQP (Advanced Product Quality Program) shall regulate the production before production There is a quality plan and previous quality analysis. FMEA (failure mode and impact analysis) analyzes and proposes measures to prevent potential failure of the product. MSA (measuring system analysis) must analyze changes in measurement results to confirm measurement reliability. SPC (statistical process control ) Master the production process and product quality changes by applying statistical techniques. Therefore, the first step for PCB manufacturers to enter the automotive electronics market is to obtain the TS16949 certificate.

Basic performance requirements

  • High reliability

There are two main aspects of vehicle reliability: life and environmental resistance. The former refers to the normal operation can be guaranteed for a lifetime. The latter refers to the fact that the PCB function remains unchanged when the environment changes.

The average car life in the 1990s was in the range from 8 to 10 years. The current range is from 10 to 12 years, which means that automotive electronic systems and PCBs should be in this range.

In the application process, the car should withstand climate change. From extremely cold winter to hot summer, from sunlight to rain. And environmental changes caused by the temperature rise caused by its own operation. In other words, automotive electronic systems and PCBs must withstand multiple environmental challenges, including temperature, humidity, rain, acid mist, vibration, electromagnetic interference, and current surges. In addition, since PCBs are assembled inside cars, they are mainly affected by temperature and humidity.

  • Lightweight and miniaturized

Lightweight and miniaturized cars are conducive to energy saving. Light weight comes from the weight reduction of each component. For example, some metal parts are replaced by engineering plastic parts. In addition, automotive electronic equipment and PCB should be miniature. For example, the volume of the ECU (Electronic Control Unit) used in automobiles in early 2000 was about 1200cm 3, and less than 300cm 3, a reduction of 4 times. In addition, the starting point of firearms has changed from mechanical firearms connected by wires to electronic firearms connected internally by flexible wires and PCBs. The volume and weight have been reduced by more than 10 times. The shrinkage of light-weight PCBs stems from increased density, reduced area, thinness and multiple layers.

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Performance attributes of automotive PCB

Multi-class automotive PCB

Automobiles combine mechanical and electronic equipment. Modern automotive technology combines traditional technology and advanced science and technology. In modern automobiles, electronic devices with different functions in different locations, and electronic devices with different functions come from different types of PCBs.

According to substrate materials, automotive PCBs can be divided into two categories: inorganic ceramic-based PCBs and organic resin-based PCBs. The ceramic PCB has high temperature resistance and excellent dimensional stability, and can be directly applied to high temperature motor systems. However, it has poor ceramic manufacturability and high cost. At present, with the development of resin substrate materials in terms of heat resistance, resin-based PCBs have been widely used in automobiles, and substrate materials with different properties are applied in different locations.

Flex PCBs and rigid PCBs are used in ordinary instruments, indicating speed and mileage, and air conditioning equipment. Double-layer or multi-layer PCB and Flex PCB are used for audio and video entertainment equipment in automobiles. For communication and wireless positioning equipment and security control equipment, multi-layer PCB, HDI PCB and Flex PCB are applied.

In the automotive motor control system and power transmission control system, special circuit boards should be used, such as metal-based PCBs and flexible rigid PCBs. For automotive miniatures, component embedded PCBs are used. For example, a microprocessor chip is used in a power controller, directly embedded in the power controller PCB. Another example is that component-embedded PCBs are also used to automatically support system navigation equipment and stereo imaging equipment.

Manufacturing characteristics of automotive PCB

  • High-frequency substrate

Automobile anti-collision/predictive braking safety systems act as military radar equipment. Since the automotive PCB is responsible for transmitting microwave high-frequency signals, it is necessary to apply the substrate with low dielectric loss together with the ordinary substrate material as PTFE. Unlike FR4 materials, PTFE or similar high-frequency substrate materials require special drilling speeds and feed speeds during the drilling process.

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  • Thick copper PCB

Automotive electronic products bring more heat energy due to high density and high power. Hybrid and electric motors often require more advanced power transmission systems and more electronic functions. This leads to more requirements for heat dissipation and large current.

Manufacturing thick copper double-layer PCBs is relatively easy, while manufacturing thick copper multilayer PCBs is much more difficult. The key lies in the thick copper image etching and thickness air filling.

The surface difference between the inner conductor of the thick copper multi-layer PCB and the insulating substrate material and the ordinary multi-layer board is too large to fill the resin completely and create a cavity. To solve this problem, thin prepregs with a high resin content should be coated as much as possible. The thickness of the internal wiring copper on some multilayer PCBs is uneven, and different prepregs can be applied to areas where the copper thickness difference is large or small.

  • Component embedding

Component embedded PCBs are widely used in mobile phones to increase assembly density and reduce component size. This is also used by other electronic devices. Therefore, component-embedded PCBs are also used in automotive electronic equipment.

  • HDI technology

One of the key functions of automotive electronics is entertainment and communication, in which smart phones and tablets require HDI PCB. Therefore, the technologies included in the HDI PCB, such as micro-via drilling and amplifiers. Electroplating and lamination positioning are used in automotive PCB manufacturing.

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