Today, with the trend of ultra-thin, intelligent and multi-functional consumer electronics, the increasing power and the thinner the product, the problem of heat dissipation is an urgent problem for engineers.
The problem of heat dissipation is long-lasting. Metal materials such as copper, aluminum and silver are used initially. They are generally called traditional heat-conducting materials. These materials have high density, high expansion coefficient and low thermal conductivity (thermal conductivity: silver) It is 430W/mK, copper 400W/mK, aluminum 238W/mK) to completely fail to meet the current development needs.
At present, there are three main types of die-cut materials for heat-dissipating materials on the market: natural graphite heat-dissipating film, artificial graphite heat-dissipating film, nano-heat-dissipating film, natural graphite heat-dissipating film. The first problem is that it cannot be made very thin, generally the thinnest product is 0.1MM. Thickness, this thickness occupies too much space in the structure of the mobile phone. If the heat-dissipating film is used in multiple parts of the mobile phone, it will directly affect the structure of the machine. Under the premise that the mobile phone is becoming thinner, the market share of natural graphite is increasing. The lower the temperature, due to the structural factors of natural graphite, the heat dissipation effect of natural graphite is the worst of the three materials, the thermal conductivity of 400W / mK artificial graphite can be very thin, the heat dissipation effect is very good, mainly reflected in the heat dissipation rate is very Fast, thermal conductivity is, but a big problem with artificial graphite is that the price is too expensive, such a price is becoming more and more strict for the mobile phone designers today. And graphite heat-dissipating film has a common problem, that is, graphite is extruded, and the finished product process must be glued, coated, and processed with many defects, etc. At the same time, in the die-cutting process, the edge of graphite is easy to fall off. Therefore, it is still necessary to do the edge processing, and it is very troublesome. Therefore, for the mobile phone R&D personnel and cost control personnel of the terminal, the price of the material of the graphite sheet itself is already very expensive, but the processing fee and the die cutting management fee of the graphite sheet have Time is more expensive than materials, so the cost pressure is great.
The nano heat dissipating film can be divided into a graphene heat dissipating film, a nano carbon heat dissipating film, a nano metal heat dissipating film, and the like.
Graphene heat-dissipating film, a new material of a single-layer sheet structure composed of carbon atoms. Graphene has always been considered a hypothetical structure and cannot be stabilized alone until 2004, when the physicists of the University of Manchester, André Heim and Konstantin Novoselov, succeeded in experimenting with graphite. Graphene was isolated and it was confirmed that it could exist alone. The thinnest and lightest features: 0.34nm thick, specific surface area of 2630m2/g, the highest thermal conductivity: 3000-6000W/mK, but its shortcomings are not currently mass-produced, and the production cost is very expensive, but the potential is great.
Nano-carbon material heat-dissipating film, the thinnest can achieve 0.03MM, nano-carbon and graphite are allotropes, the heat dissipation principle is similar, the heat dissipation power of nano-carbon is 1000-6000. The heat dissipation is very effective. At the same time, the nano-carbon heat-dissipating film is already finished, and the processing can only be opened by die-cutting, and the cutting process can be simple and the cost is low. The most important factor is that the cost of the nano-carbon heat-dissipating film is not high, and the price is lower on the market than artificial graphite.
The nano-metal heat-dissipating film is made of nano-metal material as a carrier (for example, nano-copper, etc.), and then processed in other processes to achieve rapid cooling. For example, Guangzhou Jiacheng W3 homogeneous thermal conductive material appears on the market. This technology, Guangzhou Jiacheng W3 homothermal thermal conductive material can not be used to quickly spread the temperature, and can also convert the thermal energy into the energy of the material, so that the purpose of rapid cooling can be achieved, the cooling of the whole machine is very obvious, the whole machine can be The 6-20OC drop, the processing of such materials is very simple, the processing is only open mold, punching can be, the price is far lower and artificial graphite and nano carbon material heat film, is a very competitive product.
Looking into the future, die-cutting of heat-dissipating materials will be dominated by nano-materials, graphene heat-dissipating films and nano-carbon heat-dissipating films, and nano-metal heat-dissipating films will be matched.