Recently, Prof. LIU Jing from the Technical Institute of Physics and Chemistry (TIPC) of Chinese Academy of Sciences (CAS) published a cutting edge book Advanced Liquid Metal Cooling for Chip, Device and System (Shanghai Scientific & Technical Publishers, 2020) to interpret the latest top cooling technologies. This publication is the first ever book to summarize the core principles and practical applications of a brand-new advanced chip cooling category: Liquid metal cooling.   

An explosive growth of personal computers, communication systems and workstations in the microelectronic industry is witnessed in the last two decades. Meanwhile, the chip integration density is approaching its limit due to “thermal barrier” encountered. As it is well-known, over-heating of a computer chip would result in shortened life, malfunction, low reliability and failure of work. Therefore, removal of the large amount of heat generated in the electronic components remains a big challenge facing by modern system designers and thermal management engineers. However, most of the currently available advanced thermal management techniques are not sufficient enough to cope with the ever increasing devices’ power density like 100–1,000 W/cm2 and the more compact package technology.   

At the year around 2000-2002, Prof. LIU proposed to adopt metals with extremely low melting point and larger thermal conductivity as the cooling fluids for the thermal management of computer chip. A series of theoretical and experimental investigations have therefore been continuously carried out in his lab, aiming to develop the new generation liquid metal cooling category. Compared to the conventional heat transfer fluids, low melting point liquid metals are rather desirable for thermal management of high power density devices. Liquid metal has large thermal conductivity and electrical conductivity, low vapor pressure, low dissolution in water and extensive temperature range over which they remain in the liquid phase.   

This book is an output of Prof. LIU’s more than 16 years’ continuous academic endeavors. It is dedicated to draft a new area towards advanced cooling based on room temperature liquid metal and present a systematic overview on the latest science and art developed therein. Several major categories are outlined: 1. Liquid metal as thermal interface material in reducing heat conduction resistance between neighboring contacting objects. 2. Liquid metal as flowing coolant in enhancing convective heat transport. 3. Hybrid cooling via mixed liquid metal and surrounding solution together. 4. Low melting point metal for phase change cooling, heat absorption or energy storage. 5. Liquid metal for typical high flux chip cooling or thermal management. Basic features of liquid metal, key mechanisms of the advanced cooling modality and future directions are also summarized and suggested in the book.  

With both uniquely important fundamental and practical values, this book is intended for researchers to set up their foundation and then find new ways of making advanced cooling system to fulfill the increasingly urgent needs in modern highly integrated chip industry. The book is published with the support of China National Publication Funding. 

Figure.Advanced Liquid Metal Cooling for Chip, Device and System, Published by Shanghai Scientific & Technical Publishers (Image by LIU Jing)