What Do You Know about Automotive PCBs in 2022?


What do you know about automotive PCBs in 2022?PCB boards are an integral part of the development of automotive electronics, and automotive electronics are an important future trend. Rising electronic rates have led to increased demand for automotive PCB boards and higher quality requirements . PCB boards are becoming more and more rigorous. Today's gasoline cars, diesel cars, new energy cars, electric cars, agricultural cars, motorcycles, racing cars, special vehicles, military vehicles, mountain bikes, special cruise vehicles, unmanned combat vehicles, unmanned vehicles, toy vehicles, etc. Circuits are required when PCBs are integrated, and the quality and performance requirements of automotive electronics are much higher than the requirements of consumer PCB integrated circuits related to personal safety and safe use. I will .

First of all, automotive electronics have their own rigorous quality system in the industry.

Automotive PCB manufacturers must comply with ISO 9001 regulations. PCB manufacturers are fully compliant with ISO9001: 2008 quality management systems and are committed to complying with the strictest standards in manufacturing and assembly.

Each automobile product has its own characteristics. In 1994, Ford, General Motors and Chrysler jointly established the quality management system QS9000 in the automotive industry. At the beginning of the 21st century, a new quality management system for the automobile industry, ISO / IAT F16949, was announced in compliance with the ISO9001 standard.

ISO / IATF16949 is a set of technical regulations for the global automotive industry. Based on ISO9001, coupled with the special requirements of the automotive industry, we focus on defect prevention and reduce quality fluctuations and waste that are easily generated in the automotive parts supply chain. When implementing ISO / IATF16949, special attention should be paid to the following five main tools: PPAP (Manufacturing Part Approval Process). This stipulates that the product must be approved by the customer before mass production or after modification. APQP (Advanced Product Quality Planning), which pre-runs quality planning and previous quality analysis in production, followed by FMEA (Failure Mode and Effects Analysis) analysis to prevent potential product failures. It stipulates that we propose countermeasures for. MSA (Measurement System Analysis) needs to analyze changes in measurement results. To ensure the reliability of measurements, SPC (Statistical Process Control) learns manufacturing procedures and uses statistical methods to change product quality. Therefore, the first step for PCB manufacturers to enter the automotive electronics market is to obtain an IATF 16949 certificate.

One of the world's leading printed circuit board manufacturers, has long been compliant with ISO9001 / IATF16949 quality management system standard management, providing high quality HDI PCB, Embedded bus bar PCB, thick copper PCB, high frequency PCB. I did . , Copper core PCB and technical support to contribute to the development of the automobile industry .

• Basic performance requirements

a. High reliability

Automotive reliability comes from two main aspects: longevity and environmental resistance. The former refers to the fact that normal operation is guaranteed over its useful life, and the latter refers to the fact that PCB functions remain the same as the environment changes.

The average life expectancy of a car in the 1990s was 8-10 years, but now it is 10-12 years. That is, both the automotive electronics and PCBs should be within this range.

The application process must withstand the effects of climate change from frigid winters to hot summers, sunlight to rain, and environmental changes caused by rising temperatures due to driving a private car. In other words, automotive electronics and PCBs must withstand multiple environmental issues such as temperature, humidity, rain, acid rain, vibration, electromagnetic interference, and current surges. Also, because PCBs are assembled in the car, they are primarily affected by temperature and humidity.

b. Lightweight and small size

Lightweight and small cars are suitable for energy saving. Lightness comes from the weight reduction of each ingredient. For example, some metal parts have been replaced with engineering plastic parts. In addition, both automotive electronics and PCBs need to be miniaturized. For example, the volume of ECUs (electronic control units) for automobiles has been about 1200 cm3 since 2000, but less than 300 cm3, it decreases four times. In addition, the starting point firearm has changed from a wire-connected mechanical firearm to an electronic firearm connected by a flexible wire with a PCB inside, reducing volume and weight by a factor of 10.

The weight and size of PCBs is due to increased density, reduced area, reduced thickness, and multi-layering.

Types of PCBs for automobiles

• High frequency board

The vehicle collision avoidance / predictive braking safety system acts as a military radar device. Since automotive PCBs are responsible for transmitting microwave high frequency signals, low dielectric loss substrates must be used with the common substrate material PTFE. Unlike FR4 materials, PTFE or similar high frequency matrix materials require special drilling and feed rates during the drilling process.

• Thick copper PCB

Due to high density, high power, hybrid power, the electronic equipment of the vehicle brings more heat energy, and the electric vehicle tends to require more advanced power transmission system and more electronic functions, heat dissipation and large Advocate higher requirements for current.

thick copper two-layer PCB is relatively easy, but creating a thick copper multi-layer PCB is much more difficult. Important is the image etching of thick copper and the filling of thick vacancies.

Since the internal pathways of thick copper multilayer PCBs are all thick copper, pattern transfer photoresists are also relatively thick and require very high etching resistance. Thick copper pattern etching time is long and the etching equipment and technical conditions are in the best condition to ensure perfect routing of thick copper. When manufacturing external thick copper wiring, the combination of laminating relatively thick copper foil and patterning thick copper layers can be performed first, followed by film void etching. The drywall resist for pattern plating is also relatively thick.

The surface difference between the inner conductor of the thick copper multilayer board and the insulating substrate material is large, and the resin cannot be completely filled by normal multilayer board lamination, resulting in cavities. To solve this problem, it is necessary to use a thin prepreg with a high resin content as much as possible. The copper thickness of the internal wiring of some multi-layer PCBs is not uniform, and different prepregs can be used in areas where the copper thickness difference is large or small .

One of the key features of automotive electronics is the entertainment and communication that smartphones and tablets require HDI PCB . Therefore, the technologies contained in HDI PCB, such as micro via drills, electroplating, and lamination positioning , apply to automotive PCB manufacturing.

So far, the rapid changes in automotive technology and the continuous upgrade of automotive electronic capabilities have led to a dramatic increase in PCB applications. It is imperative for engineers and PCB manufacturers to focus on new technologies and content to meet higher automotive requirements.

Busbars are high current printed circuit boards and are also the integration of busbars and electronic systems. It is a technology that combines high current and microelectronic control in a single system for powertrain and electrical applications. This combination adds busbars and other bulk copper wire to the printed circuit board (PCB) for high current capacity and heat dissipation from power loss components.

Embedded busbar PCB printed circuit board is a copper core embedded in a slot that has been pre-milled during the press process. Laminated prepregs are used to connect copper cores to printed circuit boards. The embedded copper core is in direct contact with the internal FR4 epoxy board and the PCB is used to quickly transfer heat to the copper block. The heat is then removed from the air through the copper core. The heat dissipation effect is better than the embedded copper core PCB, the process is simple, the cost is low and the application prospects are wide.

The main function of the busbar is to carry a large current. Busbar PCB require high current distribution units (also known as busbar copper electric busbars) that are widely used in the new energy industry, such as electric vehicle motor controllers, high voltage distribution boxes, frequency converters, and photovoltaic inverters. is. High voltage, used for inverters High current converter bus PCB products for inverters, wind converters, rail transport, car traction equipment, communication and data equipment and other equipment. This product provides simple, traditional high-voltage and high-current distribution and can be deployed in traditional complex low-voltage control circuits. A typical application in the automotive industry or aeronautical electronics processes a current of about 1000 amperes.

The thermal conductivity of copper in the metal core PCB manufacturing process is as high as 384 W / (m · K). Heat is the directional thermal pad (PAD) and electricity is the positive and negative electrodes. The two are separated by an insulating material to form a special thermal pad. The role of the thermal pad is to conduct heat. The main function of the electrode is to conduct electricity. This packaging method is called thermoelectric separation. , It has many advantages, mainly LED heat sink design is very convenient. The large area of bare copper is designed as a large boss that conducts heat in direct contact with the copper base and heat sink, greatly improving the heat dissipation effect. Copper core PCB thermoelectric separation products can fully solve the heat generation and light efficiency problems in the use of automotive lamps, with the advantages of fast heat dissipation, high brightness and energy saving.

The thermoelectrically separated copper substrate PCB structure is suitable for high frequency circuits, areas with large changes between high and low temperatures, heat dissipation of precision communication equipment, and all the hottest LED car headlights including front and rear car lights are copper . Made of core pcb .