Industry dynamic

In high power integrated circuits and high power density in the field of electronic industry, with the development of electronic devices and products to the high degree of integration, high operational direction, dissipated power re-double, thermal issue gradually becomes the key factor to limit it’s development. So, R&D of high thermal conductivity materials is very important. Carbon materials have high thermal conductivity, according to the calculation, graphite thermal conductivity parallel to the crystal layer in theory could achieve as high as ４１８０Ｗ·ｍ-１·Ｋ-１,which is almost 10 times over silver、aluminum &cooper, with good prospects for development.

  1、DTF(diamond thin film)

     Natural diamond thermal conductivity in room temperature is top high in known natural materials, ２０００～２１００Ｗ·ｍ-１·Ｋ-１.The thermal conductivity of synthetic diamond single crystal can be ２９９０Ｗ·ｍ-１·Ｋ-１ at ３６℃. The production process of synthetic diamond depends on high temperature and high pressure technology, greatly increase the cost of production; Since the chemical vapor deposition method was used for preparing diamond film, the film products could be large area、 high quality and the cost is relatively low. Obtain transparent diamond films using DC hot cathode vapor deposition method on tantalum plate, the size of the diameter of thin film is４０～８０ｍｍ, the film thickness is up to 4.2mm, the thermal conductivity is 1000 ~ 1200W - M-1 - K-1.

  2、Graphite

     Natural graphite (002) surface conductivity rate at room temperature is 2200W - M-1 - K-1, but ordinary polycrystalline graphite thermal conductivity at room temperature is only 70 ~ 150W - M-1 - K-1. High fixed direction pyrolytic graphite  thermal conductivity can reach 2000W - M-1 - K-1; Polyimide film artificial graphite film is made by carbonization and graphitization after heat treatment, which is with graphite array orientation and high thermal conductivity, the thermal conductivity can reach 1000 ~ 1600W - M-1 - K-1.

  3、Graphene

     Graphene is a single layer graphite carbon atoms material separated from graphite carbon atoms, with a single layer carbon atoms planar structure of hexagonal honeycomb is composed of closely arranged, single layer graphene thermal conductivity at room temperature can reach 3000 ~ 5300W - M-1 - K-1. China has successfully prepared the 696.78cm2 monolayer grapheme, this will greatly expand the application prospects of grapheme, which will have a profound impact on the design and manufacture of mobile phone, tablet computer and other electronic products to the consumer terminal.

  4、Carbon nanotubes and their composites

     The carbon nanotube is a low dimensional structure material which is formed by the carbon atoms in the single or multi layer graphite. Carbon nanotubes have good electrical and thermal conductivity，and transfer heat energy only in one-dimensional axial. According to reports, the thermal conductivity of carbon nanotubes (Length of 2.6 m, diameter of 1.7nm) at room temperature reaches 3500Ｗ·ｍ-１·Ｋ-１, high thermal conductive polymer matrix could be obtained by filling the carbon nanotubes into polymer.

  5、Carbon fiber and C/C composite materials

     Carbon fibre is made by organic fiber or low molecular hydrocarbon gas feedstock in inert gas with carbonization and high temperature graphite treatment. After the graphite lattice is highly preferred oriented in the axial direction of the fiber, it will have a high thermal conductivity. C/C composites made of high thermal carbon fiber have a series of outstanding performance such as the high temperature, the coefficient of thermal expansion is small, good self - lubricating and high thermal conductivity etc.