A hybrid sheet of nanofiller/PDMS composite with thermal dissipation and EMI shielding properties for foldable displays

To integrate excellent heat dissipation and electromagnetic interference (EMI) shielding properties, some flexible hybrid sheets were fabricated using a polydimethylsiloxane (PMDS) matrix for a foldable display. The PDMS matrix was filled with Cu flakes and silicon carbide (SiC) powder, known for its high thermal conductivity and excellent EMI shielding properties, improving heat dissipation and EMI shielding. The acrylate resin used for an adhesive had Graphene powder and hexagonal-boron nitride (h-BN) as fillers with high heat dissipation characteristics. The optical microscopy confirmed multiple heat-transfer paths formed by the fillers. In the fabricated foldable hybrid sheet, the in-plane and out-of-plane thermal conductivities were 0.81 $ \textrm{W}/\textrm{mk} $ W/mk and 0.61 $ \textrm{W}/\textrm{mk} $ W/mk, respectively. EMI shielding rate was 11.67 $ \textrm{dB} $ dB (X Band, 8 similar to 12 $ \textrm{GHz} $ GHz). In addition, the hybrid sheet exhibited excellent flexibility without microcracks in 2R repeated bending tests over 300,000 cycles.