The complete guide to automotive PCB assembly

The Complete Guide To Automotive PCB Assembly
Table of Contents

In the automotive sector, electronics are increasingly the decisive element. That poses difficult problems for engineers. Their products must, on the one hand, deliver ever-improving performance, but on the other hand, price per volume continues to be a key consideration.

Automotive PCBA is what helps to replace the diesel injection pump chip, which includes an immobilizer and ZDCAN. People should choose automotive PCBAs correctly because they can help them keep the stock control unit in place and, simultaneously, make a simple replacement.

What is the difference between PCB and PCBA?

These multi-layered, interconnected printed circuit boards form the basis of PCBs and PCBAs. A PCB refers to the design stage of a product, while a PCBA refers to the assembled product.

PCB: printed circuit board


A printed circuit board (PCB) is a flat board of copper. It contains a pattern of conductive traces using various techniques (e.g., silk screening, electroplating) to form an electrical circuit. These conductive traces route signals throughout the product and connect to other components. The purpose of a PCB determines whether it is single-sided or double-sided.

PCBA: printed circuit board assembly


Printed circuit board assembly (PCBA) involves mounting components onto a PCB before its assembly. A machine operator follows instructions from an engineer to ensure all components are securely attached and properly positioned on the board’s layers. Following quality control testing, this assembly is ready for installation into its final product.

Types of automotive PCBs

Automotive PCBAs come in several different types and sizes. The most common types include:

  • Led PCBs: These are used for backlighting or other lighting applications in automobiles. They are also used in front-end applications like instrument clusters and displays.
  • Flexible PCBs:These are flexible boards that can be bent around corners, making them ideal for front-end applications where space is limited.
  • Heavy copper PCBs: They have a thicker copper layer than standard PCBs, allowing them to run hotter and dissipate heat more efficiently. They’re also made from more durable materials than traditional boards, which makes them ideal for high-temperature applications like engine control units (ECUs).

What does automotive PCBA mean?

Automotive PCBA is a printed circuit board assembly (PCBA) used in the automotive industry. The term PCBA refers to the fact that the board is made of multiple layers of PCB material, and solder, or other conductive materials, are used to create connections between these layers. This automotive PCBA has been specifically designed for vehicles and can be found in cars and trucks.

Applications of PCB assembly in the automotive industry

Automotive PCBA assembly is a very important process. Engineers handle it with the utmost care, especially in the automotive industry. The market for automotive electronics is on the rise, and PCBs play a major role in this growth.

Here are some of the applications of automotive PCBA assembly in the automotive industry:

  • Airbag controls: Airbags are an integral part of an automobile’s safety system and can save lives in case of accidents. The control unit of airbags is often made up of a PCB that connects all the components, making it easier to install and test them before putting them into use.

Airbag controls

  • Anti-lock brake systems:  help prevent skidding during braking, which helps improve vehicle stability and reduces fuel consumption. This system uses sensors to detect any skidding condition and then controls the braking pressure accordingly to prevent it from happening again.

Anti-lock brake systems

  • Climate control: The main function of an electronic climate control system is to provide comfort to the driver and passengers by maintaining a constant temperature inside the car. It also has other functions, such as automatic defogging, seat heating, and ventilation control, all controlled by buttons or knobs on the dashboard.

man hand turning on car air conditioning system

  • Digital displays: Digital displays are used in most modern vehicles to provide accurate information about vehicle speed, fuel level, and other parameters. The data is displayed on an LCD or LED screen through ICs, integrated circuits containing several transistors and resistors. These ICs can be mounted on a PCB using surface mount technology (SMT).

Digital displays

What performance properties do automotive PCBs have?

In the automotive industry, automotive PCBAs are used in various applications. The following is a list of performance properties that automotive PCBs have:

  • Workable for complex systems: An automotive circuit board must be able to handle complex systems such as engine control computers, airbag controls, and steering wheels. It must also be able to deal with high temperatures and vibrations.
  • Resistant to chemical corrosion: The PCB must resist chemicals such as salt water, oil, and gasoline. It must withstand exposure to these chemicals without causing any damage or malfunction to the vehicle’s electrical system.
  • High reliability: An automotive circuit board has many components that make up its functionality, such as switches, relays, and sensors. These components must function properly at all times so that they do not cause any problems with the car’s performance or safety features.
  • Resistant to dirt: An automotive circuit board is exposed to a lot of dirt due to its proximity to other parts of the car’s interior (such as seats). Therefore, this component needs to withstand harsh environments and resist dust buildup, not to affect its functionality.

What are the manufacturing features of automotive PCBs?

The manufacturing features of automotive PCBAs include:

  • High reliability: The automotive industry is highly regulated and demanding, especially in the automotive electronics market. Automotive PCBs must withstand extreme temperatures, vibration, shock, and harsh chemicals.

High reliability

  • Low cost: To meet the strict price requirements of the automotive market, manufacturers must reduce costs by using automation and reducing assembly time. The automated assembly also ensures consistency in production quality and reduces defects that can lead to recalls.
  • Small size: Smaller parts are easier to fit into tight spaces in cars, which reduces overall weight.

Small size

  • High performance: The performance of automotive PCBs is critical for safety reasons — if a control unit fails during a crucial moment, such as when braking hard or turning sharply, it can lead to disaster. Therefore, automotive PCBs need to be designed with high reliability and high-performance characteristics in mind from the beginning of the design process onward.

What are the processes of automotive PCB assembly?

Automotive PCBA assembly is a complex process involving multiple steps and components. The following article will give you an overview of the processes involved in automotive PCB assembly.

Solder paste stencil

Solder paste stenciling is the first step in the assembly process. After the preparation of stencils, a dispenser applies the solder paste. The stencils are then placed on top of each component on the automotive PCBA. Once all the components have been added to the board, they are baked in an oven at high temperature for several minutes until all air bubbles have been eliminated between the components and their soldered pads.

Solder Paste Stencil

Pick and place

After solder paste stencil, pick and place machines place all components on top of their respective pads. This step is done by placing a vacuum nozzle over each component and lowering it into position with a robotic arm. If a component doesn’t fit properly or becomes dislodged during this phase, it will be discarded and replaced by another one that fits correctly.

Reflow soldering

Reflow soldering is used to solder components on printed circuit boards (PCBs). Many types of components can be soldered using this method, including through-hole components, surface mount components, BGA packages, and more. Reflow soldering is a process that requires a trained technician to perform the process and ensure proper quality control properly.

Reflow Soldering

Inspection and quality control

Once all of the necessary steps in the assembly process have been completed, it’s time to inspect and verify the quality of each product. This is done by testing each product to ensure that all aspects function as expected. This can include testing electrical signals and conducting physical inspections of each product before it leaves the facility for shipment.

Final inspection and functional test

The final inspection ensures that every product meets your specifications before being shipped out for use in your end-product or device. This process includes functional tests and visual reviews to ensure that each item meets all requirements for functionality and appearance before shipping out to your final destination.

PCB Functional Test

How do we select substrates of automotive PCBs?

  • Substrate Material

The most common substrate materials for automotive PCBAs are FR4 and Rogers, which have good thermal stability, electrical properties, and mechanical strength. The advantages of FR4 include low cost, high thermal stability, good strength, and flame resistance, but the disadvantage is poor dielectric properties. Rogers has excellent dielectric properties but a higher cost and lower thermal stability than FR4.

  • Thickness of Substrate

The thickness of the substrate can be determined by considering the size of each component on the circuit board to ensure sufficient space for all components without affecting each other’s performance. The thickness of the substrate should also meet product and processing requirements, such as drilling holes and etching holes in PCBs during production processes.

  • Thickness Tolerance

The allowable deviation in thickness tolerance is 0.05mm~0.10mm, which is based on experience gained from production processes and customer requirements for different applications; this tolerance can be adjusted according to the actual needs of customers when purchasing materials or purchasing PCBs from factories directly after production.

  • Cost

The more expensive materials have more advantages than less expensive ones but may not be necessary for all applications.

  • Mechanical Properties

This includes strength, stiffness, and thermal expansion coefficient. These are important because they can affect how a PCB will perform over time under various environmental conditions such as temperature changes, moisture exposure, etc.

What factors affect the quality of automotive PCBs?

The quality of automotive PCBAs is crucial in determining cars’ overall performance. To meet the requirements of various markets, these PCBs must be made of high-quality materials and have optimal performance.

What factors affect the quality of automotive PCBs

Many factors can affect the quality of automotive PCB boards. Some of these include:

  • The material used for manufacturing the automotive PCBA
  • The type of circuit board technology that is used to manufacture it
  • The environmental conditions under which the PCB is manufactured

Considerations when designing an automotive PCB

Here are five factors to keep in mind while designing an automotive PCBA board

  • Power and Ground Planes
  • Track Design
  • Pad and Hole Dimension
  • Signal Integrity and RF Issues
  • Thermal Issues.

Automotive industry standards for PCB design and manufacture

The automotive industry is a high-tech, high-cost production environment that demands rigid quality controls. The demands of the automotive industry have created a set of standards for PCB design and manufacture, which engineers around the world use.

These standards ensure that every printed circuit board (PCB) meets the highest quality. They apply to both standard and custom-made PCBs and include the following:

AEC-Q100 is an automotive electronics standard developed by SEMI. It is used to ensure the reliability of electronic components in automobiles, including automotive PCBA.

IPC-A-610 is an international standard for quality management systems in electronics manufacturing. It was developed by the International Electrotechnical Commission (IEC) Technical Committee 80 (TC80). IPC-A-610 provides requirements for companies that manufacture electronic equipment such as printed circuit boards (PCBs).


IATF 16949 is an internationally recognized quality management system standard that specifies requirements for implementing a quality management system. It meets customer requirements while minimizing risks to employees, assets, facilities, and the environment.

IATF 16949

SAE J1169-2002 (Class 2) standard defines printed circuit boards used in lead-acid batteries, including safety requirements, electrical performance specifications, and physical dimensions and mounting features. It also specifies methods for testing compliance with these requirements.

Future of PCB in the automotive industry

The automotive industry is one of the fastest growing industries in the world. With the increasing demand for cars, there has been a growing need for better technology, which has led to a significant rise in the use of electronics in vehicles.

The automotive industry is one of the fastest growing industries in the world

The use of automotive PCBAs in the automotive industry has several benefits. They are easy to manufacture and have a longer lifespan than their counterparts. They are also highly resistant to vibrations and shocks, making them ideal for use in vehicles with common conditions. In addition, they are cheaper than other types of circuit boards, making them an affordable option for most manufacturers.

Even though automotive PCBAs have been used for many years by car manufacturers, there is still more room for improvement and innovation in this area. There will always be new ways to improve safety features or add new features to keep up with consumer demands.

FAQs about automotive PCBA

What is the role of PCB assembly in automobiles?

The role of PCB assembly in automobiles is critical to the performance and reliability of the vehicle. PCBs are crucial in operating various electronic modules like engine management systems, airbags, power windows, etc. The need for high-quality PCBs has increased as automotive manufacturers strive to achieve higher safety standards and fuel efficiency.

PCBA is vital in automobiles

What are some of the environmental impacts on automotive PCBA?

Automotive PCBAs are also affected by environmental factors to a certain extent.

  • The pressure of multiple loads on automotive PCBA can cause the board to crack, leading to product failure and waste of resources.
  • The climatic temperature can affect the quality of the automotive PCBA. When the temperature is high, the solder joints and components may be over-expanded, resulting in increased thermal stress on the board and component terminals.

climate temperature

  • Moisture can also cause damage to electronic components. When moisture enters through the holes of electronic components, it will cause corrosion or oxidation and thus reduce their reliability.
  • Vibration is another factor affecting automotive PCBA quality. The vibration during transportation or installation may affect soldering joints between terminals and connectors, causing short circuits and failure in operation control signals.


Considerations when choosing an automotive PCB manufacturer

When choosing an automotive PCB board manufacturer, there are several things that you must consider. Here are some of the most important ones:

  1. Do they have experience in automotive PCB assembly?
  2. What is their lead time?
  3. What is their minimum order quantity (MOQ)?
  4. Are they ISO 9001 certified?
  5. What is their pricing structure and method (cost-plus or fixed price basis)?


The market for automotive PCBA is constantly growing

The market for automotive PCBA is constantly growing. This can be attributed to the rising demand for automotive technology worldwide, especially as developing nations adopt vehicles due to their comparative advantages over other forms of transport in some cases.