How to solve the heat dissipation problem in automotive chip design?

With the continuous advancement of chip manufacturing technology, chip packaging has become more and more complex, especially in automobiles and embedded devices. These devices are usually small in size and highly integrated, which makes the heat dissipation problem more severe, affecting the reliability and service life of the equipment. How can automobiles solve these challenges and their potential solutions from the perspective of chip and structural design?

Part 1

Embedding chips in stacked chip assemblies creates significant heat dissipation issues. In the past, these complex designs were primarily used in environments such as data centers, where overheating issues could be quickly resolved by shifting some of the computing load. However, as technology has evolved, these stacked chip assemblies have been increasingly used in safety-critical applications such as automotive sensors and pacemakers.

Thermal cycling has a direct impact on chip reliability. Every time a chip is turned on or off, it undergoes a process of heating, cooling, expansion, and contraction. When the chip is tightly enclosed, the cooling time is significantly extended, increasing the risk of failure.

Thermal management is absolutely necessary. If not managed properly, it can lead to performance loss, unreliable operation, device failure, and increased system costs. Many embedded devices involve different materials with different coefficients of thermal expansion, which can easily cause chip warping and deformation, further destroying the connection between the computing element and the substrate, and reducing device performance.

In embedded devices, heat is not only generated by the components themselves, but also by neighboring components. For example, automotive sensors may be affected by heat and vibration depending on their location. This means that both thermal and mechanical stress can become a problem. Heterogeneity at the package level increases the complexity of the design and makes thermal management more difficult.

Traditional cooling solutions such as fans and heat sinks are not always ideal in embedded devices. Fans can generate electrical interference and are easily damaged, affecting system reliability. As the number of transistors increases and the speed of operation increases, the need for heat dissipation also increases. Even efficient heat sinks can hardly completely solve the problem of heat accumulation.

Ambient temperature and usage scenarios can also pose additional challenges to the thermal management of the device. For example, the device may need to work under extreme temperature conditions, such as the high temperatures in Phoenix or the low temperatures in Edmonton, Canada. Designers must consider these environmental factors and reserve sufficient safety margins to cope with possible extreme conditions.

Part 2

To address these thermal issues, designers can take a variety of approaches. Extensive thermal simulation and prototyping early in the design cycle is key. Using digital twin technology can more accurately predict thermal performance under actual workloads. Physical improvements are also critical. Various forms of cooling can be used in the package, such as heat sinks and thermal interface materials (TIMs). When stacking chips, structures such as copper pillars can be introduced to help dissipate heat.

Thermal simulation from a multi-physics perspective is also very important. “Thermal simulation requires a volume mesh rather than a surface mesh because heat flows in three directions,” Ansys’ Swinnen noted. Using a volume mesh of the device, the effects of power spread and ambient temperature can be simulated more accurately.

Heat dissipation is a long-standing challenge in embedded and discrete device design. Increasing power density makes it more difficult to dissipate heat. In the future, solving these problems may require new materials (such as glass substrates) and new thinking about existing components. Designers must find the best balance between power, thermal management, and device performance to ensure the reliability and safety of the device in a variety of environments.

summary

Solving the heat dissipation problem is not only a technical challenge, but also requires innovative thinking and multidisciplinary collaboration. By continuously optimizing the design and manufacturing process, we can achieve more efficient thermal management in embedded devices and provide more reliable support for intelligent driving and other key applications.