China's Chip process is still in the transition stage from 14 nm to 7 nm, two generations behind the manufacturing level of developed countries (5 nm). High-end Chip is extremely scarce, ranking first in imported goods, and independent research and development of it cannot be delayed. In the development of high-performance Chip, a series of changes such as the reduction of the size of the Chip internal field effect tube, the increase of unit density, and the increase of operating frequency make it difficult to effectively and quickly diffuse a large amount of joule heat to the Chip shell and the heat sink in contact. The accumulated heat makes the Chip temperature rise rapidly, which has harmful effects on the stability, reliability and life of Chip components, and has become a "stuck neck" problem that cannot be ignored in self-research. This team has carried out in-depth research on micro-nano scale interface heat transfer mechanism and regulation, and developed thermal conductivity materials such as graphene, carbon nanotube fibers, vertical/horizontal/hybrid carbon nanotube arrays, and self-assembled monolayer with high interface thermal conductivity characteristics, and integrated with Chip packaging structure, and strive to solve the "disease" of Chip heat dissipation.
Carbon nanotube fiber: The strategy of "phonon resonance and macromolecular crosslinking" is proposed to improve the thermal conductivity of carbon tube interface. Polar molecules such as ethanol are introduced into the primary interface to shorten the tube spacing. The low frequency phonon resonance is activated by nano-elements such as noble metal particles and iodine chains at the secondary interface. The three-stage interface (between the bundle and the polymer molecular chain) controls the molecular chain content to minimize the increase of tube spacing caused by excessive. The thermal conductivity of the carbon tube fiber has been increased by nearly 6 times (374 W/ K, which is equivalent to the international advanced level of 380 W/ K).
Vertical/horizontal/hybrid carbon nanotube arrays: A strategy to control the contact area of the microstructure by stages is proposed to improve the thermal conductivity of the carbon tube array-heat sink interface. In the preparation stage of the carbon tube array, the operating parameters of the carbon source and carrier gas are adjusted to improve the height uniformity and diameter of the array, which is conducive to forming more effective contact area with heat sink. During the application phase, the contact area is further enhanced by applying coating, mechanical shear and compression. The interface thermal conductivity of the carbon tube array and heat sink has been increased by nearly 50 times (3.3×106 W/m2 K, the international leader).
Self-assembled monolayer: The solution method is used to prepare a high thermal conductivity self-assembled monolayer that can be orderly arranged on the chip surface, so that the heat generated inside the chip can be quickly transferred to the chip surface, and then dissipated through heat deposition, avoiding problems such as chip performance degradation and damage caused by excessive temperature. The resulting self-assembled monolayer can increase the thermal conductivity of the interface between chip and the packaging material by nearly 3 times.
CCVD operation experimental platform: Through the gas path control system to accurately regulate the carbon source, protection atmosphere and standard gas flow, the use of three-temperature zone tube furnace to achieve gradient heating and stable temperature control, efficient synthesis of carbon nanotube arrays and graphene.
Home
>>Research Focus
MOBILE Version
