The challenges of thermal management of next-generation electronic equipment

The Chinese and Greek authors of a recent review paper (1) stress that electronic chips are the most important components for the development of technologies such as the Internet, artificial intelligence, supercomputers, etc. To enable high performance and high integration, the power density of electronic chips must increase dramatically, yielding much higher heat-dissipation requirements.

 

If heat cannot be removed in time, a local hotspot with a large temperature gradient will directly affect the performance and operational reliability of such electronic devices. Therefore, long-time stable and reliable operation of high-performance chips requires a high-efficiency thermal management strategy to eliminate high-heat flux and maintain a device’s temperature below its limits. 

 

Recent studies have indicated that about 55% of electronic equipment failure is related to high temperatures. Moreover, when component temperatures exceed their normal operating range, each 10°C increase in temperature results in a 50% decrease in system reliability (2).  

 

Today, electronic chips can produce heat fluxes as high as 10–100 W/cm². In next-generation electronic systems, the typical heat flux may even exceed 1000 W/cm². However, the cooling capacity of the conventional heat-dissipation methods (air cooling, microchannel, semiconductor cooling, heat pipes, etc.) is less than 100 W/cm2, which cannot meet the increasingly stringent chip-cooling requirements.  

 

According to the authors of the article (1), one of the solutions to this cooling problem is the spray-cooling technique. Compared with the traditional cooling technology, spray cooling has advantages such as small heat-transfer temperature difference, high heat removal capability with a small amount of working fluid consumption, precise temperature control and uniform temperature distribution over the cooling surface. 

 

Thus, spray cooling using water as a working fluid has demonstrated a strong ability to remove heat fluxes as high as 1000 W/cm2. Therefore, it has great potential in the future heat dissipation of high-power electronic equipment. 

 

However, many parameters affect the heat-transfer performance of spray systems, including spray parameters (nozzle type, flow rate, spray angle, etc.), types of working fluid, surface modification, and environmental parameters.  

 

Spray cooling systems have been designed for high-performance computers and data centers, spacecraft, hybrid electric vehicles, and reactor pressure vessels, but have not been widely industrializsd.  

 

Moreover, current electronic devices tend to be more miniaturised and integrated. How to adapt complex spray-cooling systems to the limited space of small electronic devices is a key issue to further develop the application of spray-cooling technology. 

 

(1) Jin Y. et al, Spray Cooling as a High-Efficient Thermal Management Solution: A Review, Energies 2022, 15, 8547. See in FRIDOC.

(2) Zhang T., Advanced Study of Spray Cooling: From Theories to Applications, Energies 2022, 15, 9219. See in FRIDOC.