Thermally Detachable Conformal Electromagnetic Interference Shielding Film With Segregated Conductive Networks for Repairable Electronics.

The escalating demand for miniaturized and high-frequency electronics necessitates next-generation electromagnetic interference (EMI) shielding materials that offer both conformal adaptability and repairability. Herein, we present a thermally detachable conformal shielding film (DCSF) comprising thermally expandable microspheres (TEMs), silver flakes (Ag), thermoplastic polyurethane (TPU), epoxy resin (EP). The TEMs induce a segregated conductive network within the DCSF, enabling exceptional electrical conductivity of 10884 ± 211 S·cm-1 and ultralow contact resistance of 1.30 ± 0.01 mΩ·mm-2. The formation of the Ag-TPU/EP-TEM heterogeneous interface enhances multiple reflections and interface scattering of electromagnetic waves, achieving outstanding EMI shielding effectiveness of 93.7 ± 0.4 dB and near-field shielding effectiveness of beyond 56 dBm. Crucially, the embedded TEMs facilitate on-demand detachment from printed circuit board assemblies (PCBAs) upon heating above 180°C. This detachment mechanism operates via isotropic interfacial stresses generated during volumetric expansion of the TEM, significantly reducing the film-substrate contact area. Consequently, the DCSF enables residue-free removal without damaging underlying electronic components. By simultaneously addressing critical challenges in EMI suppression and component reparability, the DCSF provides a novel strategy for solvent-free and mechanically nondestructive electronics recovery holding significant promise for sustainable consumer electronics.