Composites Based On Cyanate Ester Resin For Microelectrical Packaging

Micorelectronic packaging is an integrated technology which constitutes the electronic circuit semiconductor components and electronic components into electronic devices. With the development of microelectrical technology, microelectrical packaging is playing more and more important role. High density, high frequency and high speed stand for the development direction of this technology. In order to meet the needs of microelectronic industries, especially the high performance microelectronic products, the materials for electrical packaging must have more and better properties including higher thermal conductivity, lower dielectric constant, better thermal stability and mechanical properties.Cyanate ester (CE) resins are high performance thermosettings, which have excellent dielectric properties, especially very low and stable dielectric constant and dielectric loss over a wide ranges of temperature and frequency, outstanding thermal and mechanical propertities, as well as good processing characteristics, so CE resins have been considered as the most competitive resins for high performence microelectrical packaging. However, CEs have low thermal conductivity limiting their applications for high performance microelectronic packaging.The purpose of this thesis is to develop high performance composites based on CE resin for microelectrical packaging with high thermal conductivity, low dielectric constant and good mechanical property.Three composites based on CE resin, aluminum nitride (AlN), and silicon dioxide (SiO2), coded as AlN/CE, AlN-SiO2/CE and AlN(KH560)-SiO2(KH560)/CE composite, respectively, were developed for the first time. The thermal conductivity and dielectric properties of all composites were investigated in detail. Results show that properties of fillers in composites have great influence on the thermal conductivity and dielectric properties of composites. When the volume fracition of fillers reaches 60%, the thermal conductivity (λ) of composites are 6 times higher than that of neat CE resin. The thermal conductivity is greatly dependent on filler content when fillers content is high (>50vol%). The surface treatment of fillers is beneficial to increase the thermal conductivity and reduce the dielectric constant of the composites. Comparing with binary composite, when the filler content is high, ternary composites possess lower thermal conductivity and dielectric constant. The reasons leading to these outcomes are discussed intensively.A new ternary composites based on AlN and a blended matrix of polypropylene (PP) and CE, code as AlN/CE-PP, were prepared, and the distribution and morphology of components were investigated. The relationship with thermal conductivity and dielectric properties were also studied. Results show thatλvalues of all composites are higher than neat CE resin. The blend ratio of PP and CE has a significant effect onλ. At the research scope of this thesis, the composite has the hightestλwhen the mass fraction of PP in the blended matrix is 30%. Then theλvalue decreases with continuous increase of the PP content. The conversion of the continuous phase in matrix and the distribution of AlN are the key reasons for the above change ofλvalue. The dielectric properties are also dependent on PP content. The dielectric constant of the composite decreases with the increase of the PP content.A series of CE composites based on different AlN content, coded as AlN/CE, were developed, the effect of AlN content on dynamic mechanical property of composites was investigated intensively. Results show that AlN content has great effect on dynamic mechanical properties of AlN/CE composites. The storage modulus in the glassy region increases linearly with the addition of AlN as well as the increase of AlN content. When the mass friction of AlN reaches 60% the storage modulus of the composite is 2.6 times higher than neat CE resin. Meanwhile, all composites also exhibit notably higher loss modulus than cured CE resin due to the appearance of new energy dissipation form. In addition, AlN content has negative effect on Tg. All reasons leading to the phenomena are analyzed from the view of structure–property relationship.