China develops artificial diamonds to cool chips

In the global artificial intelligence (AI) race, China is leading the production of super-large synthetic diamonds, a key material that helps disperse heat from semiconductors. As chip performance is increasingly limited by the physical challenge of heat, a series of breakthroughs in the development of large single-crystal diamonds promises to give China an edge in producing next-generation AI hardware.

Theo South China Morning Postresearcher Zhu Jiaqi and colleagues at the School of Aerospace Engineering at Harbin Institute of Technology (HIT) developed technology that can produce high-purity single-crystal diamonds of any shape and size from jewelry to wafers. The team used microwave plasma chemical vapor deposition (MPCVD) to create carbon atoms in an ultra-clean environment, then layered them onto diamond seed crystals.

While HIT provides many of the core technologies, refines MPCVD development techniques and increases crystal sizes, Sinomach Group’s engineering team solves one of the most persistent challenges in the industry: wafer warping (the phenomenon of semiconductor wafers becoming deformed, crooked or not completely flat during fabrication or processing). According to Science and Technology Dailythrough optimization of the powder formulation and compression ring conditions, they reduced the deformation in the diamond heatsink to a microscopic level, allowing precise integration with semiconductor devices.

Nanjing Realway New Materials Technology solved another major obstacle: bonding diamond to copper. Due to poor chemical compatibility, these two materials are difficult to adhere to in nature. By developing specialized metal alloying and plating techniques, the company reduces the thermal resistance at the diamond-copper interface by 80%. Henan Carbon Core Material Technology Company has contributed to the commercialization of this technology, turning laboratory prototypes into mass-produced thermal management products.

While conventional synthetic diamonds are only a few millimeters wide, Chinese researchers have increased the crystal size to 15.2 cm and recently more than 20 cm. Huanghe Whirlwind Company in Henan Province is producing diamond radiators about 20.3 cm in diameter, only slightly smaller than a basketball (24 cm). This heatsink is designed to be placed directly above the hottest area of ​​the chip. For AI processors containing billions of transistors packed into increasingly small footprints, efficient heat management is becoming a necessity.

The AI ​​industry is facing the challenge of handling heat as power consumption increases due to next-generation accelerators and dense computing clusters. Conventional copper radiators are approaching physical limits. The thermal conductivity of copper is around 400 watts per meter – degrees Celsius while diamond can exceed 2,000 watts per meter – degrees Celsius, five times higher. According to Bloombergthe AI ​​boom has increased demand for synthetic diamonds as they become effective cooling materials in advanced chip manufacturing, allowing for more powerful and compact AI chips. This is a superior alternative to traditional solutions such as copper or aluminum. Diamond heatsinks also have thermal expansion properties compatible with gallium nitride (GaN) and silicon carbide (SiC), reducing mechanical stress.

SF Diamond Company in Zhengzhou, Henan Province started delivering diamond radiators in small batches after passing tests by foreign customers. Henan Liliang Diamond Company also revealed that it has begun production of the first phase of its high-power radiator project.

At the Consumer Electronics Show in early January, Nvidia announced it would eliminate traditional cooling methods for the company’s next generation of GPUs. Instead, they will switch to a thermal management system based on diamond-copper composites incorporating liquid cooling to meet AI’s growing power and water needs.