Synchronously Enhancing Through‐Plane Thermal Conductivity and Near‐Field Electromagnetic Interference Shielding Effectiveness of Aligned‐Graphite Composites for Advanced Microelectronic Packaging

Abstract The application of composites that integrate functions of thermally conductive and electromagnetic interference (EMI) shielding in advanced microelectronic packaging has provided an effective solution to the heat dissipation and electromagnetic compatibility issues of electronic devices. Graphite flakes, with their outstanding electrical and thermal conductivities, are widely regarded as ideal candidates for creating composites that achieve both thermal conductivity and EMI shielding. However, the anisotropic properties of graphite lead to significant differences in electrical and thermal conductivity in different directions, which may limit their applications. To overcome this issue, the vertically aligned graphite (VG), nickel‐coated graphite (Ni@G), and silicone gel (SG) composites (VG‐Ni@G‐SG) have been successfully fabricated via shear‐induced alignment and ultrasonic cutting technology. The VG‐Ni@G‐SG composites synchronously achieve high through‐plane thermal conductivity of 15.8 W m −1 K −1 and near‐field shielding effectiveness (NF‐SE) of −68 dB in the frequency range of 500 MHz–7 GHz, and also exhibit a low compression modulus of 0.6 MPa, which is essential for reducing packaging thickness and improving electromagnetic sealing and heat dissipation of electronics. The VG‐Ni@G‐SG composites demonstrate promising prospects for the miniaturization and high performance of modern electronic devices.