Automotive Electronics
Automotive Electronics
Major Challenges for Automotive Electronic Manufacturing Service providers?
Wide Working Temperature Range
The working environment of the automotive is even harsh. The temperature range of the engine compartment is between -40°C and 150°C. Therefore, automotive chips and circuit boards need to meet this wide temperature range, while consumer chips only need to meet 0°C C~70°C working environment. More, vehicles are sold worldwide, and different regions often have different environmental characteristics of temperatures and humidity. Therefore, automotive PCBs must be able to adapt to different environments, although some manufacturers make PCBs for specific environments.
Long Product Life Cycle
The design lifetime of an automobile product is longer. The life cycle of mobile phones is 3 years, but not more than 5 years at most. In comparison, the design life of automobiles is generally around 15 years or 200,000 kilometers, far longer than the life requirements of consumer electronics products. Therefore, the automotive product life cycle must be more than 15 years, while the supply cycle may be as long as 30 years.
High Reliability
The PCB and components mounted on the boards must follow high-reliability standards because it is related to the safety of operation and life. Generally, automobiles are made of strong materials with stable performance and can work well in harsh environments.
Adapt to a Harsh Environment
The vehicle will encounter more vibration and shock on the road; the vehicle’s electronic system needs to resist the threat of various chemical corrosion such as corrosive acid, organic solvent, salt water, etc. Therefore, the circuits must have a certain anti-corrosion ability; the electronic system ensures that automotive circuit boards resist the accumulation of dirt during years of operation is critical. Usually, automotive PCBA manufacturers use special laminates to prevent dirt on the board so that we can use this PCBA even in dusty environments.
High-Security Requests
In addition to providing comfort, the automotive must ensure the safety of the entire vehicle system and even zero defects. In addition, with the popularization of electric vehicles, the importance of information security is becoming more and more prominent. As a real-time online device, The communication between it and the network, including the communication with the in-vehicle network, requires data encryption.
What are the common automotive electronics standards?
Looking back at the history of the automotive industry, automotive electronics has become the most important supporting foundation for automotive control systems, and automotive electrification has become a symbol of the automotive industry revolution. The industry will develop in the direction of intelligence, networking, and deep electronics. As a complex industrial product, the use environment generally affects the durability and operational performance of electronic equipment and units. Therefore, the environmental reliability of automotive electronic sections has become one of the core issues of automotive reliability.
ISO Standards
The application environment of automotive electronic products includes electromagnetic, electrical, climatic, mechanical, chemical, etc. At present, the standard environmental conditions and test standards for automotive electronics formulated by ISO mainly include the following aspects:
ISO 16750-1: Road vehicles – Environmental conditions and tests for electrical and electronic products: General
ISO16750-2: Road vehicles – Environmental conditions and tests for electrical and electronic products: Power supply environment
ISO16750-3: Road vehicles – Environmental conditions and tests for electrical and electronic products: Mechanical environment
ISO16750-4: Road vehicles – Environmental conditions and tests for electrical and electronic products: Climatic environment
ISO16750-5: Road vehicles – Environmental conditions and tests for electrical and electronic products: Chemical environment
ISO20653 Automotive electronic equipment protection level against foreign objects, water, and contact
ISO21848 Road vehicles – Electrical and electronic equipment power supply environment with a supply voltage of 42V
AEC series standards
These standards are most focused on the components used in the car, In the 1990s, Chrysler, Ford, and General Motors established the Automotive Electronics Council (AEC) to establish a common set of parts qualifications and quality system standards. AEC established standards for quality control. The AEC-Q-100 Qualified Specification for Chip Stress Testing is AEC’s first standard. AEC-Q-100 was published in 1994. Since the above three car manufacturers can adopt the parts that meet the AEC specifications simultaneously, it has promoted the willingness of parts manufacturers to exchange their product characteristic data and implemented the universality of auto parts. The AEC standard has gradually become a general test specification for automotive electronic components. After more than 10 years of development, AEC-Q-100 has become a common standard for automotive electronic systems. After AEC-Q-100, specifications such as AEC-Q-101 for discrete components and AEC-Q-200 for passive components have been formulated, as well as guiding principles such as AEC-Q001/Q002/Q003/Q004.
TS16949
TS16949 is the technical specification of the international automobile industry. It is based on ISO9001 and added the technical specification of the automotive industry. This specification is consistent with ISO9000:2008 but focuses more on defect prevention and reducing quality fluctuations and waste that are prone to occur in the auto parts supply chain. The pertinence and applicability of the ISO/TS16949 standard are very clear. It is only applicable to automobile manufacturers and their direct spare parts manufacturers. That is to say, these manufacturers must be directly related to the production of automobiles and can carry out processing and manufacturing activities. This activity enables products to add value. At the same time, there are also strict restrictions on the qualifications of the certified company manufacturers. Those units with only support functions, such as design centers, company headquarters, and distribution centers, or those that manufacture equipment and tools for vehicle manufacturers or auto parts manufacturers are not certified. Five major supervisory bodies manage ISO/TS16949:2009 certification on behalf of the IATF, which use the same procedural approach to supervise the operation and implementation of the ISO/TS16949 specification to form a fully uniform standard and operation around the world.
What Kind of PCBs are in Automotive Electronics?
Electric cars have consistent, indispensable, and innovative requirements. Now Tesla leads the innovation wave. But any manufacturing and design innovation on electric cars requires highly durable, reliable, and rugged PCB applications. High-performance automotive PCB requirements significantly can withstand harsh driving conditions and can become a catalyst for innovations of growing new energy driving systems.
PCB demand for electric vehicles mainly comes from power train-related equipment—onboards, battery management systems (BMS), voltage conversion systems (DC-DC, inverters, etc.), and other high-voltage and low-voltage devices. In addition, millimeter-wave radar is an important sensing device for realizing intelligent driving and even autonomous driving, and it has obvious advantages compared with other sensors.
High-power copper-plated PCBs are one of the emerging industry’s most widely used PCB applications. Flexible PCBs, HDI PCBs, and LED PCBs are major applications used on AC/DC power converters, audio and video, digital displays, braking systems, automatic dimming, electronic mirror control, automotive lighting, and Engine timing system, and remote diagnosis system. Eashub offers the below solutions for the automotive product:
| PCB Type | Multi Layers | LED | High Frequency | Aluminum | Thick Copper | High Tg | HDI | Flexible | Rigid Flex |
| Automotive | x | x | x | x | x | x | x | x | x |
Our Automotive PCB
Layers: 8 L Thickness: 1.2mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.15mm Min Line Width/Space: 3mil
Surface Finish: ENIG Application: GPS Navigate
Layers: 8 L Thickness: 1.6mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.25mm
Min Line Width/Space: 4mil
Surface Finish: ENIG
Application: GPS
Layers: 6 L Thickness: 1.6mm
Out Layer Copper Thickness: 1 OZ
Inner Layer Copper Thickness: 1 OZ
Min Hole Size: 0.25mm
Min Line Width/Space: 4mil
Surface Finish: ENIG Application: Entertainment
Eashub's Capabilities of Automotive Electronics Assembly
Eashub has many years of experience in the automotive industry. Eashub’s strategic EMS partner ranks among the top 5 in the world’s largest contract manufacturing supplier of automotive products. It has many years of experience serving Volkswagen, BOSHI, SAIC Motor, etc., and Kara Group, our factory stakeholders. It is also a leading EMS company in Japan, with a history of serving Denso and Honda automotive.
Leading industry qualifications:
The factory owns certifications as TS16949、, ISO9001、 ISO14001 ANSI/ESD S20.20.
Full process capability:
– BGA and Micro BGA placement
– Cable and Harness Assemblies
– Box assembled
– IC programming
– ICT/FCT
– X-ray inspection
– AOI
Automotive specific process
– Class 100 Clean Room
– Selective Solder Wave
– High Voltage Test
– Aging test
– Conformal Coating
– Aqueous Washing
– Third-Party Reliability Testing
Other tips about automotive product manufacturing
What factors can cause PCB failure in the production of automotive PCBs, the common environmental loads and PCB assembly and their possible failure modes are as follows:
Possible failure modes
- Plated through-holes or internal copper cracks
- Cracks in the outer copper layer
- Microvia Cracks
- Semi-cured cracks
- Solder mask crack
Electrochemical Migration on PCB Surface
- PCB environmental load
- Temperature cycling and storage
- bending
- shock
- humidity
- Combination of several loads
- Lamination technology
The above factors will affect the reliability of automotive PCB manufacturing. In order to manufacture high-quality automotive PCBs, let us understand the performance requirements of automotive PCBs and how to test them to ensure high quality.
Compact size and light
Reasonably reducing the size and weight of the automotive can save more fuel, electricity, energy, and improve environmental protection. Therefore, the size of the automotive is becoming more and more compact. Due to the automotive’s overall size reduction, the automotive PCB will inevitably become more compact and lighter.
High reliability
The high reliability of automotive PCB means that within the normal service life of the automotive, the PCB can maintain good stable performance in the face of different complex environments. In other words, automotive PCBs must be able to withstand a variety of environmental interfaces, including humidity resistance, water resistance, heat resistance, corrosion resistance, vibration resistance, and electromagnetic interference resistance.
Automotive PCB reliability is closely related to our safety, so various reliability tests must be passed when manufacturing automotive PCBs. Automotive PCBs in different locations require different reliability tests. Common tests include:
1) Thermal shock test
Automotive PCBs must normally work in a high-temperature environment caused by external heat or the high temperature from self-generated heat. Automotive PCBs must withstand the shock of sudden changes in heat, and we need to conduct thermal shock tests on automotive PCBs.
2) Thermal cycle test
According to different positions of the automotive, the PCB thermal cycle test has different levels. The commonly used PCB thermal cycle temperatures are as follows:
Location | Class | Low Temperature | High Temperature |
Inside the seat | a | -40℃ | 85℃ |
Engine protection cover | b | -40℃ | 125℃ |
Engine | c | -40℃ | 145℃ |
Transmission | d | -40℃ | 155℃ |
Engine compartment | e | -40℃ | 165℃ |
3) Temperature and humidity deviation test
Changes in temperature and humidity are one of the essential factors that cause the failure of automotive PCBs, although automotive manufacturers have taken various measures to solve this problem; such as:
- Optimized materials
- Self-heating
But self-heating is often only used when the automotive is running normally, if the automotive does not run and was parked for days or weeks in a very harsh environment, such as a high tide, a highly corrosive environment. Then humidity or corrosive gas may enter the interior of electronic products through plastic or atmospheric compensation components. Then the humidity will also have a significant impact on the surface and internal structure of the PCB, causing it to fail. So let’s understand some details of PCB failure caused by temperature, humidity and bias (THB).
The image below shows the growth of conductive crystals during PCB condensation (water condensation)
Even if there is no condensation, high humidity can cause an electrical short if no strict materials are used. Surface Insulation Resistance (SIR) can drop, potentially causing electronics to fail. EASHUB’s method is to thoroughly understand the temperature and humidity conditions inside the protective cover (metal or plastic case) through simulation and experimental testing.
On the other hand, EASHUB tests the materials used (such as PCBs, devices, fluxes, thermal interface materials, or conformal coatings) and designs elements under different temperature and humidity conditions according to the SIR test method in IPC-9202.
EASHUB uses an efficient simulation model to predict the actual condition of local humidity in the ECU,
We determined the SIR of material and design within an enclosed enclosure under the harshest conditions.
To ensure that the PCB design elements and materials are safe and reliable, thus ensuring the reliability of the automotive PCB during the life cycle.
THB testing must take into account the CAF migration of the PCB. CAF usually occurs between adjacent lines or adjacent layers, vias, between vias and lines, causing insulation degradation or even short circuits. The corresponding insulation resistance depends on the distance between vias, lines and layers.
Common PCB technology for Manufacturing of Automotive PCBs
High-frequency substrate
The car’s predictive braking safety system and anti-collision system are the first line of defense for our safety assurance. Its electronic system is like a radar monitoring system. The automotive PCB of this part of the electronic system is mainly used to transmit high-frequency microwave signals. Therefore, in addition to the substrate material PTFE, it is also necessary to use a substrate with low dielectric loss. Unlike FR4 materials, PTFE or similar high-frequency matrix materials require special drilling speeds and feed rates during the drilling process.
Thick copper Techonology
As automobiles are developing towards smaller size and higher dynamic performance, automobiles need to use higher-tech power transmission systems and more complex electronic systems. Automotive PCBs have higher thermal performance and can withstand larger current surges.
Double-layer thick copper PCBs are relatively easy to make. However, multilayer thick copper PCBs are much more difficult to make due to the complexity of thick copper image etching and thick vacancy filling processes.
The internal paths of the multilayer thick copper PCB are all thick copper, so the pattern transfer photo dry film is also relatively thick and requires very high etching resistance. Because the etching time of the thick copper pattern becomes longer, the etching equipment and technology are also more demanding to ensure the complete wiring of the thick copper.
When we do external thick copper wiring fabrication, the combination between laminating a relatively thick copper foil and patterning a thick copper layer can be done first, followed by film void etching. In addition, the anti-plating dry film of pattern plating also needs to be relatively thick.
In addition to the above difficulties, we also encounter the following problems:
- The surface difference between the inner conductor of the multilayer thick copper PCB and the insulating substrate material is large.
- Ordinary multilayer board lamination cannot be completely filled with resin, and it will generate cavities.
To solve this problem, we should use thin prepregs with high resin content as much as possible. If the copper thickness of the internal routing on some multilayer PCBs is not uniform, we can use different prepregs in areas with large or small differences in copper thickness.
HDI technology
The comfort and good experience of the car are also closely related to the entertainment and communication systems built into the car. Automotive built-in entertainment microcomputers often use HDI PCBs.
HDI PCB technology includes micro-hole drilling and electroplating, lamination positioning and other processes. Due to the rapid development of automotive technology, more and more common applications in life are built into automotive systems. Therefore, with the increase in automotive electronic systems, more PCBs are bound to be used to meet the requirements of high-quality cars better.
Component embedding
In order to reduce the size of components, the assembly density of the PCB must be increased. PCBs with embedded components are widely used not only in mobile phones but also in automotive electronics.
According to different component embedding methods, the manufacturing methods of component embedded PCBs are also different. There are mainly four manufacturing methods for component embedded PCBs used in automotive electronic systems:
- Excavation type
- Lamination type
- Ceramic type
- Module type
The above is the supply technology commonly used in manufacturing automotive PCBs, so how to choose a reliable automotive PCB manufacturer.
