Design and characterization of novel doped heterostructured electromagnetic shielding packaging materials for Current sensor chip applications

Electromagnetic radiation not only disrupt the use of equipment such as sensors, electronic components and precision instruments and affects their normal operation, but also leads to the leakage of important data and even reduces their reliability. It is still challenging to significantly improve the anti-electromagnetic interference performance from the chip packaging material level. Doped polyaniline (PANI) is considered as one of the most potent electromagnetic shielding materials as its easy synthesis, stable performance, unique chemical and electromagnetic properties.to address the technical challenges of chip anti-interference in complex electromagnetic environment and make full use of the advantages of doped PANI in electromagnetic shielding, this thesis uses doped PANI, carbon fiber, metal particles, etc. to prepare heterogeneous structure composite electromagnetic shielding packaging materials. Through the modification of the material and the construction of the shielding structure, the influence of the content of functional components, the size and structure of the reflective cavity on its electromagnetic properties is systematically studied, and the mechanism of the regulation of the electromagnetic shielding performance of the material is revealed. A series of CF/PANI heterogeneous structure composite electromagnetic shielding materials were obtained by in situ polymerization of carbon fiber surface coated with PANI, through optimization of components, structure and properties. Based on the excellent electrical properties of PANI and the characteristic of no electromagnetic loss, the reflective layer is constructed inside the material, and the effects of carbon fiber and metal particle content and morphology on the conductivity and dielectric behavior of CF/PANI are systematically investigated to enhance the dielectric loss and absorption loss of the material and improve the electromagnetic shielding effectiveness of the material through multiple reflective interfaces of electromagnetic waves. With the increase of carbon fiber content, the conductivity of the material shows a trend of increasing and then decreasing, and the change of skinning depth is the opposite. When the mass ratio of carbon fiber to PANI was 6:4, the sample has the highest conductivity (10.32 ± 0.29 S/cm) and the Electromagnetic shielding efficiency values achieved 63dB. The above excellent performance gives the CF/PANI /EP composite material potential applications in the packaging of magnetic sensors, current sensing chips, SRAM and other chips.