环氧模塑料中导热通道的构造与导热性能

以低密度聚乙烯(LDPE)为原料,添加不同含量的高导热氮化硅陶瓷颗粒和短切玻璃纤维,熔融挤出不同直径的Si3N4/LDPE杆料。采用热模压法制备了环氧模塑料(EMC)。研究了杆料直径、陶瓷填充量对EMC导热性能、介电性能的影响。结果表明:在相同填充量下,杆料直径越大,样品热导率越大;5mm含玻纤杆料φ(填充量)为40%,热导率高达2.1W/(m·K)。样品的εr随杆料填充量的增大而显著减小,φ5mm含玻纤杆料填充量为40%时降至最低,为3.25(1MHz)。

Thermal conductive paths forming and thermal conductivity in epoxy molding compounds

LDPE as raw material with different contents of high thermal conductive Si3N4 ceramic particles and short cut glass fiber filled in, Si3N4/LDPE rods of different diameters were fabricated using melt extrusion. The epoxy molding compounds (EMC) was prepared by hot pressing molding method. Influences of the rads’ diameter and the ceramic filling amount on the thermal conductivity and dielectric property of EMC were studied. The results indicate that thermal conductivity of EMC is remarkably increased with the diameter of Si3N4/LDPE rods filled in, a 2.1 W/(m·K) thermal conductivity of EMC is observed with 40% 5 mm-diameter rods which contains glass fiber filled in. A remarkable decrease in εr is observed with higher volume fraction of Si3N4/LDPE rods, the lowest εr of 3.25 (1 MHz) is observed with 40% 5 mm-diameter rods which contained glass fiber filled in.