Why does PGS artificial graphite sheet have such high thermal conductivity?

In non-metallic materials, heat conduction primarily relies on phonons (quantized energy packets of lattice vibrations). Graphite sheets consist of layers of graphene, where within each graphene , carbon atoms are connected by robust sp⊃2; covalent bonds forming a hexagonal network structure. These covalent bonds are exceptionally strong and exhibit excellent vibrational coherence, enabling phonons to propagate within the with remarkable efficiency and near-zero resistance. It is the fundamental reason for its ultra-high thermal conductivity in-.

The planar thermal conductivity of graphite sheets differs significantly from their longitudinal (thickness direction) thermal conductivity, which is a highly distinctive characteristic of graphite sheets: the planar thermal conductivity is extremely high, typically ranging from 300 to 2000 W/(m·K). Its function is to rapidly and uniformly diffuse the "point" or "line" heat generated by a heat source (such as a CPU) across the entire , forming a temperature-uniform "heat-dissipating surface," and then dissipate the heat through convection with air or contact with other cooling structures (such as casings or fins). It primarily serves as a "heat diffuser" or "thermal equalization plate." The longitudinal thermal conductivity of graphite sheets is average, ranging from 5 to 20 W/(m · K). This is because only weak van der Waals forces bind between layers, making it very difficult for phonons to propagate vertically and causing significant resistance.