There is no significant breakthrough in the functional powder fillers of thermal conductive absorbing materials

Thermal conductive absorbing materialThe performance of the material is mainly achieved by adding functional powders, and the functional characteristics of the material are mainly determined by the performance of the functional fillers. At present, the thermal conductivity and absorption materials produced by various units are basically composed of two or more single functional powders to achieve dual function composite. However, functional fillers in polymer matrix materials can be added up to about 90% (mass fraction) at most. Simply using high thermal conductivity ceramics and magnetic powders for composite is close to the theoretical performance limit, and it is difficult to further improve the thermal conductivity and absorption function of the material.

Although there have been developments that combine thermal conductivity and absorption functionspowder materialThere have been reports on materials such as carbon fiber, modified aluminum nitride, carbon black, etc., but there have been no reports on the use of single functional fillers to truly improve the thermal conductivity and absorption properties of polymer matrix materials. Moreover, most of these new powder materials require nanoscale doping, modification, and modification, with complex synthesis methods and poor process repeatability, which cannot guarantee stable product performance and seriously limit the industrial application of these new materials in the field of thermal conductivity and absorption. At the same time, when these powder materials are mixed with the matrix polymer, the interfacial compatibility between the two substances is low, which easily leads to large-scale macroscopic segregation, greatly affecting the performance of the filler. After years of development, there is an urgent need for a new type of dual functional enhanced powder that can be prepared on a large scale. By using a single powder, the electromagnetic wave absorption function and thermal conductivity of the material can be synchronously improved, solving the problems of screening composite fillers and adjusting the distribution ratio in production. This provides excellent functional powder raw materials for the preparation of new thermal conductive absorbing materials.

The performance of thermal conductive absorbing materials still needs to be further improved

Heat dissipation and electromagnetic compatibility are two important factors that directly determine the performance and service life of electronic devices. If the heat generated during the device's operation cannot be timely conducted to the external environment, it will inevitably cause a significant increase in its own temperature, a decrease in working stability, or even burnout. Electromagnetic interference between devices will seriously affect the normal operation of the equipment. Therefore, within the cost budget range, electronic devices usually choose thermal pads with the highest possible performance (thermal conductivity usually greater than 5W/(m · K)) in the production design processAbsorbing patchThe reflectivity of the working frequency band is less than -10 dB. The main purpose of using thermal conductive absorbing materials is to improve the heat accumulation of electronic components inside the equipment, while reducing or shielding the electromagnetic interference generated, reducing the occupied space, and improving the compactness of the internal structure, as shown in Figure 7. However, its main indicators still have a certain gap compared to single functional materials, and the effective absorption range of existing absorbing materials is mostly located in higher frequency bands. It is still difficult to achieve low thickness strong absorption in P/L/S and other frequency bands. The auxiliary advantages of using thermal conductive absorbing materials are not enough to make up for the gap in main functional indicators, resulting in certain limitations in its application field.