The Researches Of Preparation And Properties Of AlN Ceramic Filled PTFE Substrate

PTFE polymer resin substrate is widely used in high-frequency field equipment due to its special molecular structure,stable dielectric constant,low dielectric loss,low water absorption and chemical stability.It has irreplaceable importance.This paper aims to produce an AlN/PTFE composite substrate with good thermal conductivity and other excellent performance parameters.Through detailed research and analysis,the best excellent modified coupling agent type and the best excellent modification process of AlN ceramic powder were studied.The optimum doping content of the filler of AlN/PTFE composite substrate and the optimal pre-baking temperature of the composite powder were further determined by experiments.AlN/PTFE composite substrate which has excellent performances was prepared.This paper mainly conducts experimental research from the following three aspects:1.Firstly,the AlN ceramic powders were modified by different contents of F8261,Z6124 and stearic acid respectively.The effects of the types of coupling agent in the grafting modification process of the filler surface were explored.The effect of the mass fraction of the modified reagent on the hydrophobic properties of the modified aluminum nitride ceramic powder was studied.The modification mechanism and modification effect of the modified powder were analyzed by means of SEM,XPS,XRD,etc.,thereby determining the optimum modification reagent formulation and modification process.The results show that when the content of F8261 is 1.2 wt.%,the contact angle of the modified powder is the largest(?=150.8o).When the content of Z6124 is 1.0 wt.%,the contact angle of the modified powder is the largest(?=148.4o).When the stearic acid content is 10 wt.%,the contact angle of the modified powder is the largest(?=151.1o).Based on the analysis of various data,it has concluded that the hydrophobicity of the AlN powder modified by the above formula is the best excellent in the groups.2.AlN/PTFE composite substrate was prepared by using aluminum nitride powder which modified by the optimum content of three modified reagents.The content of modified filler was used as the only variable in the same experiment,and the effects of aluminum nitride ceramic powder filler content on the performance of composite substrate were studied.The optimum modified aluminum nitride powder filling content was determined.At the same time,the micro-section analysis,dielectric properties,water absorption,thermal conductivity and other key performance parameters of the AlN/PTFE composite substrate were tested.The results show that the composite substrate which made by F8261,Z6214,stearic acid modified aluminum nitride powder,and the best doping content is 40 wt.%,45 wt.%and 35 wt.%,respectively.At this time,the performances of composite substrate are the best excellent.3.AlN/PTFE composite substrate was prepared by using 1.2 wt.%F8261 modified aluminum nitride ceramic powder,and the content of aluminum nitride ceramic was 40wt.%.The pre-baking temperature of AlN/PTFE composite powder was studied.The effects of different pre-baking temperatures on the properties of AlN/PTFE composite substrates were investigated.The results show that the AlN/PTFE composite substrate has the best comprehensive performance when the pre-baking temperature of the composite powder is 200?.