"The increase of new 5G frequency bands has greatly improved the transmission rate and corresponding indicators. In the future, the internal structure of mobile phones will be more complicated and power consumption will be higher.
5G puts forward higher requirements on mobile phones: on the one hand, signal processing and transmission capabilities are stronger. On the other hand, due to more functions, including more data operations and more complex radio frequency systems, mobile phones consume more power and require better thermal management. Zhou Wei believes that the development trend of 5G mobile phone materials is mainly to meet better signal transmission capabilities and thermal management.
Zhou Wei said that compared with the current post-4G era mobile phones, the material of the back shell of the mobile phone will not change much for the future 5G mobile phones, mainly non-metallic materials such as glass, ceramics and plastics.
Although the application of metal materials on the back shell of mobile phones is gradually decreasing, the middle frame part of the 5G era will still be mainly metal, and new requirements for metal materials are put forward. Zhou Wei introduced that in the 5G era, the speed of signal transmission has accelerated, the amount of data transmission has greatly increased, and the requirements for antenna signals and digital bandwidth are higher. In this scenario, the structure of the mobile phone is more suitable for metal middle frame + non-metal back shell.
To this end, BYD has specially developed a series of aluminum and magnesium alloy materials with high thermal conductivity to meet the new needs of industry development. Compared with the ordinary aluminum alloy material ADC12, this new type of high thermal conductivity aluminum alloy can increase the thermal conductivity by up to 20-60% and the strength by 10-50%. This kind of high thermal conductivity aluminum alloy material has been applied in batches in mobile phone terminals.
In the 5G era, the main screen area of mobile phones has increased and the thickness has become thinner. Zhou Wei said that the middle frame of mobile phones is getting thinner and thinner, and the middle frame needs higher-strength metal materials. For this reason, BYD has developed a high-strength and tough aluminum alloy whose yield strength is more than twice that of ordinary aluminum alloy material ADC12.
In addition, the PMH technology (metal-plastic integrated molding technology) invented by BYD will continue to be widely used in mobile phones, especially in the mobile phone frame of the 5G era.
It is reported that PMH technology connects finely surface-treated metal and special PMH plastic through multiple precise molding, processing and surface treatment procedures, and the two materials are seamlessly and highly connected together, and the complex structure and components of the Exquisite appearance. It was first mass-produced and applied to HTC mobile phones in 2012. Since then, BYD has opened the entire "all-metal era" of mobile phones.
Zhou Wei believes that according to the basic theory of antennas, the lower the dielectric constant of the plastic material, the larger the signal bandwidth that can be transmitted. He said that in order to meet the mobile phone’s need for better signal transmission capabilities, BYD has been launching the world’s first low-dielectric PMH plastic since 2015, and has quickly obtained large-scale mass production applications. With efforts, the dielectric constant of low-dielectric PMH plastic has been reduced from 3.3 to 2.9, and the dielectric loss has also been reduced from 0.007 to less than 0.005.
According to Zhou Wei, PMH plastic with a dielectric constant as low as 2.7 has also been successfully developed and will be applied according to the needs of industry customers.
It is understood that BYD has established the Central Research Institute, the Institute of Communications and Electronics, and the Research Institute of Automotive Engineering, which are responsible for the research and development of materials, electronic technology and automotive technology, and have expertise in product design and project management in terms of hardware, software, and testing. The team, with complete independent development experience and data accumulation of a variety of products, has gradually formed a technology development platform with its own characteristics and an international level.