Silicon/aluminum(Si/Al)composite is a kind of lightweight electronic packaging material that received a lot of attention in the past 20 years.In this paper,a series of Si/Al composites with lowered coefficient of ther...Silicon/aluminum(Si/Al)composite is a kind of lightweight electronic packaging material that received a lot of attention in the past 20 years.In this paper,a series of Si/Al composites with lowered coefficient of thermal expansion(CTE)and high thermal conductivity were produced by powder metallurgy(PM).The Si/Al composites are fully dense and have fine Si particles uniquely distributed within pure Al matrix.Three 50%Si/Al composites were designed to have strength in the range of 185-290 MPa to meet different demands,while the other properties keep invariable.Fracture toughness of the composites is measured to be 9-10 MPa·m^(1/2).The composites were machined to 50%Si/Al housings and 27%Si/Al lids.Both the hermeticities of housings before and after laser-beam-welding sealing are determined.The measured leak rate of composites and sealed housings is in magnitude order of 1×10^(-10)and 1×10^(-9)Pa·m^(3)·s^(-1),respectively,suggesting high hermeticity.The good hermeticity is attributed to the full dense materials,good weldability,and extremely low weld porosity.The present Si/Al composites are expected to be extensively used in highly hermetic electronic packages.展开更多
基金the National Basic Research Program of China(No.2012CB619600)。
文摘Silicon/aluminum(Si/Al)composite is a kind of lightweight electronic packaging material that received a lot of attention in the past 20 years.In this paper,a series of Si/Al composites with lowered coefficient of thermal expansion(CTE)and high thermal conductivity were produced by powder metallurgy(PM).The Si/Al composites are fully dense and have fine Si particles uniquely distributed within pure Al matrix.Three 50%Si/Al composites were designed to have strength in the range of 185-290 MPa to meet different demands,while the other properties keep invariable.Fracture toughness of the composites is measured to be 9-10 MPa·m^(1/2).The composites were machined to 50%Si/Al housings and 27%Si/Al lids.Both the hermeticities of housings before and after laser-beam-welding sealing are determined.The measured leak rate of composites and sealed housings is in magnitude order of 1×10^(-10)and 1×10^(-9)Pa·m^(3)·s^(-1),respectively,suggesting high hermeticity.The good hermeticity is attributed to the full dense materials,good weldability,and extremely low weld porosity.The present Si/Al composites are expected to be extensively used in highly hermetic electronic packages.
基金Project supported by the National Natural Science Foundation of China(Nos.31101783 and 31472164)the Special Fund for Independent Innovation of Agricultural Science and Technology in Jiangsu Province of China(No.CX(13)3070)
基金supported by the National Natural Science Foundation of China(Nos.31372421,31530074,and 31672515)the Fundamental Research Funds for the Central Universities(No.KYZ201415)the Priority Academic Program Development of Jiangsu Higher Education Institutions,China