Improvement of the Thermal Conductivity of Microwave Substrate by Constructing a 2D/3D Dense Phonon Transmission Network
With the advent of"5G"and deepening of the information technology revolution,electronic components are developing in the direction of high integration,miniaturization,high power and high performance,requiring devices to have better heat dissipation.In this study,hexagonal boron nitride(h-BN)with high thermal conductivity was used as 2D ceramic filler,and was introduced into the polytetrafluoroethylene(PTFE)-based microwave substrate in collaboration with 3D-like SiO2.The two components were bonded to each other,and successfully constructed a dense phonon transport network.The thermal conductivity of the dielectric layer is greatly improved(from 0.6 W/(m·K)to 1.196 W/(m·K),an increase of 99.33%).In this process,the use of advanced calendering process,through the mixed flocculation-drying-grinding-mixing-preforming-calendering process,can improve the uniformity of the medium layer,to avoid the use of glass fiber cloth brought about by the"glass fiber braid effect".At the same time,the microwave substrate maintains the low dielectric loss,suitable dielectric constant and high stripping strength of PTFE dielectric layer.When the h-BN addition reaches 26%,the thermal conductivity of the dielectric layer reaches 1.196 W/(m·K),the dielectric loss factor is 0.0008675,and the stripping strength is 1.072 N/mm.In this paper,a new idea of 2D/3D collaborative construction of dense phonon network was proposed for the development of a new dielectric layer of high thermal conductivity substrate to improve the thermal conductivity of microwave substrate.
polytetrafluoroethylenehexagonal boron nitridemicrowave substratephonon transport networksynergistic effect