Our recent SAE webinar, Material Choices to Deliver Enhanced Reliability, Performance, and Differentiation, explored how control in transportation is changing on multiple fronts as we evolve towards Level 4 and 5 autonomy. Advances in vehicle safety systems are transferring operating responsibility from the human driver to machines, while significant changes in electronic hardware and vehicle architecture have increased the volume of materials required. Furthermore, competition in the industry places mounting pressure on carmakers to differentiate their offering.
We illustrated how taking control of your material choices drives enhanced reliability, performance, and design freedom. We also explained how to extend system life through effective thermal management, including joining materials for printed circuit boards and semiconductor assembly.
Here are the key learnings from the online event:
Substantial growth has become apparent in vehicle electronics over recent years due to the evolution of electronic powertrains and advanced safety systems. The advanced safety systems sensor market, in particular, is predicted to outpace automotive sales due to a bigger reliance on the components in autonomous vehicles. It takes a synergy of multiple sensors to fully capture a vehicle’s surroundings to make an informed safety decision. Those working in the supply chain will be aware that this period of significant change goes beyond technology; there is a shift in control.
Traditionally, OEMs heavily relied on Tier 1s to produce vehicle electronics, but now they want to open the black box and understand the technology within, asking the question: how can we influence the design-build and materials to differentiate ourselves from our competitors? Due to the critical interaction between various electronic components and to sustain the need for seamless communication, OEMs are selecting fewer system providers. In response, Tier 1s are introducing multiple sensor systems as a full package for next-level autonomy, all while new players are entering the market and increasing competition.
We are also seeing changes to complex vehicle architecture, including a move from electronic control units to domain control units (DCUs) – precipitated by the volume of electronics required to create unique autonomous vehicles and the critical processing required of the safety systems. With an increase in electronic content within car models, the risk of electronic failures becomes greater. It’s clear that material choice is critical for vehicle design success. But many manufacturers get hung up on the initial outlay required for high-quality products, even though overall, they deliver a net cost reduction on a system level.
For example, let’s say a typical Level 2 vehicle costs $47,000; 30% of that is electronics ($14,100), 20% of the electronics are dedicated to advanced safety systems ($2,820), and within the advanced safety functions there are about $15 of MacDermid Alpha Electronic Solutions materials. Break it down, and the MacDermid Alpha Electronic Solutions materials are 0.53% of the total advanced safety systems cost and 0.03% of the overall vehicle price; minuscule amounts when you consider the immense safety benefits from this small initial outlay.
The shifting responsibility from humans to machines requires enhanced reliability for all systems. Automotive electronics are held to stringent standards, including rigorous testing specifications for assessing critical thermal cycling and vibrations resistance.
The biggest challenge for electronics in any application is thermal and mechanical stress. High processing speed and power used to drive such systems create high heat levels, especially in miniaturized designs. When electronic materials are heated, they expand and contract at different rates, increasing the risk of cracks which can affect the resistance of the circuit, possibly rendering the system inoperable.
A conventional leadframe package contains a metal frame with a silicone die attached and an epoxy mold for cover. These leadframe packages are being used for more advanced applications and are creating higher levels of heat; traditional die attach materials cannot remove enough heat. MacDermid Alpha Electronic Solutions provides a conductive die attach material that has much greater thermal conductivity and this material can also be used to replace structural adhesives on multiple silicone die designs. This is another positive way to remove heat from the die and dispersity through the metal lid for increased characteristic life of the package; our material can improve conductivity by a whopping 4100%.
Choosing an appropriate solder paste is also essential. Most radar sensors are manufactured with a conventional tin-silver-copper solder paste. However, by switching to a superior paste, although you initially pay more, the component’s life expectancy is extended by 40% on average while enhancing reliability for all electronic connections. This is achieved for less than 1% of the overall sensor cost.
Innolot solder alloy was developed to combat thermal and mechanical stress in the solder joint by using additives that create a needle-like crystal, strengthening the solder and delivering more resistance to metal fatigue.
One of the biggest challenges for automotive designs is the introduction and necessity for large ball grid array packages. These must be used for processing the sense and respond features housed on the domain control units (DCU). All large packages run the risk of damage to the component’s edges due to the increased mechanical stress placed on the unit. An edge bond is designed to structurally support the package in its attachment to the circuit board; a standard DCU with three processors using solder alone can expect 600 thermal cycles per lifetime. In contrast, a unit using both solder and an edge bond can offer up to 2,700 per lifetime - another example of a small initial added cost that provides a massive return on investment.
We asked our webinar participants to share their views on what they believe is a current priority in autonomous vehicle design; here are the results:
What is your top priority?
Enhanced Reliability 69.23%
Improved Performance 23.08%
Design Freedom 7.69%
Are you designing around thermal management challenges?
We are not surprised by the answers; as mentioned, enhanced reliability is the biggest concern for carmakers. When humans relinquish control to machines, autonomy brings more liability challenges. Equally, thermal management plays a massive part in advanced safety systems, so OEMs and Tier 1s are right to consider efficient heat conductivity when developing advanced safety systems components.
Differentiation becomes critical to survive and remain relevant in the ever-changing automotive market. Our specialized formulas deliver performance and reliability enhancements, allowing OEMs and Tier 1s to concentrate on system design integration. The bespoke components are developed with sustainability in mind without compromising performance, extending system life and creating less waste.
Ultimately when all carmakers begin with the same basic materials, how can they hope to develop a revolutionary vehicle?
Catch the webinar in full here.