Using silicon nitride ceramics as raw material for mobile phone backplanes

As smartphone technology continues to develop and competition intensifies, mobile phone manufacturers have launched various new designs and innovations to attract more consumers, and ceramic backplanes are one of the tricks. Its emergence began in 2012 when Sharp launched a smartphone with a ceramic backplane. However, due to technical and cost issues, ceramic backplanes were only used in a few high-end brands at that time. However, with the development of processing technology, the application range of ceramic backplanes is becoming wider and wider.

In the field of ceramic backsheets, the protagonists are almost all zirconia ceramics, but recently researchers seem to have begun to think about silicon nitride. Compared with zirconia, silicon nitride is considered by researchers to be a superior and promising mobile phone backplane material, especially whisker-toughened silicon nitride ceramics. The reasons are as follows:

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(1) Silicon nitride ceramics have higher impact toughness, are not easily broken, are not easily damaged during machining, and have a higher yield;

(2) Silicon nitride ceramic has high thermal conductivity, which is more than 10 times that of zirconia ceramic, and it is easier to dissipate heat. Therefore, the heat generated when the mobile phone is running at high speed or the battery is charging and discharging is easy to dissipate, which is beneficial to the normal operation of the mobile phone. Avoid slowdowns and other phenomena;

(3) The dielectric loss of silicon nitride ceramics is two orders of magnitude lower than that of zirconia, making it more transparent to mobile phone signals and making it easier to communicate smoothly in environments with weak signals;

(4) Silicon nitride ceramic has higher hardness and lower density than zirconia, which can effectively reduce the quality of the fuselage, and its cost is close to that of zirconia;

(5) Silicon nitride ceramic is a colorless ceramic, which is relatively easy to color and has good coloring effect. It also has a jade-like texture and is suitable for use in, for example, mid-to-high-end mobile phone casings.

Therefore, the use of silicon nitride ceramic materials as communication device mobile phone backplane materials can, to a certain extent, make up for the shortcomings of current zirconia mobile phone backplane materials, and does have certain prospects.

Although there are not many reports on silicon nitride mobile phone backplane materials, it has been used as a structural ceramic for a long time and has fully proven its application stability and reliability in harsh environments such as automobile engines. If silicon nitride is used as a new mobile phone backplane material, it not only has the same excellent mechanical properties as zirconia, but also has the advantages of good texture, light weight, and more sensitive signals. It is a new mobile phone backplane material with great potential.

At present, the key to breakthrough lies in how to optimize the process to make Si3N4 ceramics not only easy to dissipate heat and rich in color, but also the preparation process can be simple and reliable, and the cost becomes acceptable. If the above difficulties can be overcome, perhaps one day in the future we will be able to see Si3N4 on smartphone backplanes and smart wearable devices.