Diamond‐Reinforced Al(H₂PO₄)₃@Epoxy Hybrid Thermal Adhesive With Ultra‐High Thermal Conductivity and Bonding Strength

Abstract The miniaturization, integration, and increased power of electronic devices have exacerbated serious heat dissipation issues. Thermally conductive adhesives, which effectively transfer heat and firmly bond components, are critical for addressing these challenges. This paper innovatively proposed a composite comprising inorganic phosphate/alumina as a matrix and diamond as filler. The composite achieved an isotropic thermal conductivity (TC) of up to 18.96 W m⁻¹ K⁻¹, significantly surpassing existing reports while maintaining electrical insulation. First‐principles calculations and experimental tests confirmed that the high TC of phosphate and excellent interface contact ensured efficient heat transfer. To optimize bonding performance, a modified‐diamond/Al(H₂PO₄)₃@epoxy hybrid composite is subsequently developed using an organic modification method. The unique hybrid structure, combining inorganic thermal pathways and an organic adhesive network, enabled the hybrid composite to simultaneously possess a high TC (3.23 W m⁻¹ K⁻¹) and strong adhesion (14.35 MPa). Compared to previous reports, the comprehensive performance of this hybrid thermally conductive adhesive is exceptionally remarkable. The superior heat dissipation capability of the hybrid thermal adhesive is demonstrated in chip cooling scenarios. This organic/inorganic hybrid approach offered a new direction for obtaining advanced thermal interface materials, demonstrating significant application potential in chip soldering, packaging, and heat dissipation.