3DVC Solution for High Power Consumption and High Heat Flux Chips

With the progress of chip manufacturing technology, some new trends have emerged in the field of chips:
First, the power consumption of the chip is becoming higher and higher, gradually transitioning from 165 watts to 500 watts, and even developing to 1000 watts;
Secondly, the heat flux density of the chip is getting higher and higher, from 20 watts per square centimeter to 200 watts per square centimeter, and in the future, it will develop towards a higher heat flux density such as 300 watts per square centimeter;
Thirdly, for existing frameworks, the heat dissipation space has not increased, and the chip temperature requirements have not changed. Therefore, the same heat dissipation space used to require only 200 watts of heat dissipation, but now requires 500 watts of heat dissipation, or even higher, with a steep increase in difficulty;
Fourthly, more application scenarios require chips with high power consumption and high heat flux density. For example, ChatGPT, the most popular artificial intelligence robot nowadays, requires an enormous amount of high-performance GPUs to shoulder its computing power. In the future, more and more artificial intelligence will emerge, which poses very high requirements for chip thermal control, which is undoubtedly a difficult challenge and requires new heat removal solutions.

When the heat dissipation space is constant or limited, and the power consumption and heat flux density of the chip are continuously increasing, the most important thing is how to solve the heat conduction problem of the chip, increase its thermal conductivity, and reduce its thermal conductivity resistance. For air cooling, the main means of heat conduction include heat pipes, hot plates, or stacked heating pipes on hot plates. Due to the small steam channels, limited capillary limits, and low heat transfer power consumption of heat pipes, hot plates can only transfer heat along a plane, and their application is limited. The method of stacking heating pipes on hot plates is obviously much better than the heat conduction of a single heat pipe or hot plate, but due to the superposition of heat pipes on hot plates, there is an additional set of evaporation thermal resistance, For chips with higher power consumption or higher heat flux density, they still cannot meet their thermal conductivity requirements. As shown in Figure 1, 3DVC has only one evaporation thermal resistance, and the steam space is large enough to fully meet the thermal conductivity requirements of high power consumption or high heat flux chips.

Due to its structural characteristics, 3DVC has many advantages:
Firstly, it is flexible in structure and utilizes the structural characteristics of heat pipes to achieve spatial extension of 3DVC, especially in narrow and irregular spaces;
Secondly, the steam chamber has a large space, which connects the heat pipe and the steam chamber of the soaking plate, increasing the volume of the steam chamber, allowing the steam to reach the tail end of the heat pipe directly, reducing the thermal resistance from the soaking plate cover plate to the heat pipe;
Thirdly, the thermal resistance is relatively low. Compared to the soaking plate+heat pipe superposition method, the thermal resistance of 3DVC is significantly reduced due to the removal of the evaporation thermal resistance of the heat pipe, leaving only the evaporation thermal resistance of the soaking plate. This is particularly evident in applications with high power and high heat flux density. 3DVC heat transfer at low air volume is more competitive and has a greater difference.

The 3DVC structure can be divided into two types, vertical and parallel.