Ideas and Innovation Blog

Vehicles today are, in many ways, high-powered computers on wheels. The industry is packing more and more functionality into vehicles – from connectivity and entertainment features to comfort and advanced mobility applications to ADAS system integration and autonomous driving capabilities. While these enhancements improve the driver and passenger experience, they also introduce increased complexity to vehicles’ electrical architectures and electronics systems and put pressure on manufacturers to continuously enhance system performance.

To illustrate the level of advancement taking place in automotive electronics, consider a vehicle’s infotainment system. Not long ago, a CD disc changer was an innovative entertainment feature. Today, vehicles feature ever-more-robust infotainment systems that provide passengers with unique and customized experiences. These systems include touch screens, music streaming capabilities, advanced navigation, voice-command capabilities, and even 360-degree camera views.

The challenge: Increasing functionality, power and complexity (in extreme and harsh environments) while decreasing the footprint

The increased functionality of infotainment systems is creating unique challenges for engineers who are designing systems, components, modules and PCBs. First, PCBs aren’t getting bigger, but they still must accommodate more micros, pads and circuits. The result is a more powerful PCB (in effect, a “superior” PCB). While the PCB is crowded with components – which creates design and operability challenges – it drives higher performance in next-gen electronics.

Further, the stringent electrical and manufacturability requirements of automotive customers create a second challenge for PCB engineers. While new board design processes can help accommodate the many components that support increased functionality – and these processes have been successfully used in consumer electronics for decades – PCB manufacturers in the automotive industry must account for challenging specifications and extreme environments.

So, how do PCB engineers fit all the necessary inputs and outputs on their boards while also ensuring reliable, long-term operation in demanding environments?

The solution: Transition to HDI

To ensure more crowded PCBs function reliably, manufacturers must transition from using multi-layer board (MLB) designs to high-density interconnection (HDI) designs. With a MLB, design engineers use the Through Hole process to connect each copper layer of the PCB. When working with a HDI, design engineers use Blind Micro Via to connect selected copper layers. The ability to connect selected layers allows the manufacturer to include more connections in a limited space, increasing the number of inputs and outputs, and therefore increasing functionality without increasing the size of the PCB.

Further, by transitioning from MLB to HDI, the pitch of the PCB is reduced from 150-200 μm to less than 150 μm. A finer pitch allows for more circuits to be deployed on the PCB, again increasing functionality. Additionally, the finer pitch and use of Blind Micro Via allow design engineers to implement more complex geometric structures to accommodate the electrical and physical requirements of automotive applications.

The transition from MLB to HDI, and from Through Hole to Blind Micro Via, allows design engineers to improve uniformity and maximize the design density of the PCB, thus optimizing reliability. But to successfully make this transition, engineers need advanced metallization, copper plating and dry film photoresist processes. When these processes are optimized, they help engineers improve reliability and signal integrity on crowded boards. Further, consistent metallization, plating and photoresist processes can help engineers improve manufacturing yield and productivity.

PCB innovation: Designing for the future

Considering the speed of innovation in the automotive industry, it is guaranteed that next-gen vehicles will require even more functionality than today’s most advanced vehicles. Therefore, the board density and the environmental and operational demands of automotive applications will continue to increase. In response to these trends, design engineers must leverage innovative processes to ensure the reliable performance of high-powered infotainment and other advanced electronics systems in next-gen vehicles.

The transition from MLB to HDI is a critical step that will help engineers meet the performance requirements of advanced infotainment systems. This transition requires new metallization capabilities to take advantage of the benefits of HDI and accommodate more interconnects in more tightly packed spaces.

Application examples: HDI in action

Example 1

When an automotive customer struggled with reliability issues in its new audio product, our team identified the cause was due to improper process control and equipment issues. Using CircupositTM 4000 electroless copper – which offers strong copper to copper bonds to guarantee higher thermal cycle and thermal shock to improve reliability – DuPont Interconnect Solutions was able to support the new audio system and resolve the audio reliability issues.

Further, the customer experienced sustainability benefits by using CircupositTM 4000 electroless copper. The electroless copper bath allowed the customer to reduce water consumption for bath maintenance.

Example 2

A customer needed to upgrade its manufacturing capabilities, including adding via-fill technology, to win new opportunities with automotive OEMs. We helped the customer integrate MicrofillTM EVF-III – a next-gen via-fill electrolytic copper solution – to support electrolytic plating of HDIs. Due to our technical skill and decades of expertise, we were able to quickly scale up their process to mass production volume and help the customer win new orders with its OEM customers.

Example 3

An automotive PCB manufacturer required finer pitch to accommodate more connections on a PCB. Using our Riston® DI3000 series dry film photoresist, we were able to drive the pitch capability as low as 100μm, allowing the customer to add more interconnects to the board, therefore increasing functionality of the vehicles’ infotainment system.