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Physical, mechanical, thermal, and dielectric behavior of surface modified hexagonal boron nitride (hBN) in epoxy matrix was investigated in this paper. Effective treatment of microsize boron nitride involved silane coupling agent, (γ‐aminopropyl)triethoxysilane such that the coating resulted from the treatment amounted to 2% of the weight of silane coupling agent of the treated BN. The present work revealed that the chemical treatment of BN surface could effectively enhance the adhesion between matrix and filler material. The dispersion and wettability of the BN powder in epoxy matrix after surface treatment were improved. These imparted improved physical and excellent mechanical and thermal properties to the developed material. The experimental study on thermal properties of fabricated composites indicated that incorporation of modified particles exhibits improved glass transition temperature. As filler loading increases, coefficient of thermal expansion of composite decreases which further decreases when treated filler were used. Further, appreciable improvement in thermal conductivity is obtained when treated hBN is used in place of untreated one. The dielectric properties are investigated for wide frequency range and filler content and found to be increased with hBN content and decrease with frequency enhancement. Furthermore, mechanical properties of such composites were also largely enhanced when treated fillers were used. With modified properties, the presently developed material is suitable for microelectronic applications. [ABSTRACT FROM AUTHOR]

The main focus of the work is on developing a new class of hybrid composite with polyester as the continuous phase and micro-sized hexagonal boron nitride (hBN) and short sisal fibre as the discontinuous phases. The effect of loading of discontinuous phases on the different properties of the composites is analysed experimentally. The incorporation of either of the discontinuous phases unwillingly increases the void content and water absorption rate. With hBN content, the density increases, whereas, with sisal fibre content density decreases. The hybrid combination of fillers successfully improves the glass transition temperature (Tg) and coefficient of thermal expansion (CTE) of the polymeric resin. The maximum Tg reported is 106.2°C and the minimum CTE reported is 51.7 × 10−6/oC for the polyester reinforced with 40 wt. % hBN and 5 wt. % sisal fibre. The incorporation of hBN upsurges the thermal conductivity but also increases the dielectric properties. The dielectric properties gainfully reduce with the addition of sisal fibre. Dielectric properties also decrease with an increase in the working frequency. The incorporation of sisal fibre slightly reduces the thermal conductivity of the composites. The mechanical properties like tensile strength and flexural strength of the hybrid composite increase when the combination of hybrid fillers is judicially selected, whereas, the compressive strength and hardness of the composite increase with filler/fibre loading with maximum 131.4 MPa and 80.0 Shore D number, respectively. Due to the improved overall properties, the composite material under investigation can find its potential application in various microelectronic applications. [ABSTRACT FROM AUTHOR]

To develop a new class of composites with adequately high thermal conductivity and suitably controlled dielectric constant for electronic packages and printed circuit board applications, polymer composites are prepared with microsized Al2O3 particle as filler having an average particle size of 80-100 μm. Epoxy and polypropylene (PP) are chosen as matrix materials for this study. Fabrication of epoxy-based composite is done by hand lay-up technique and its counterpart PP-based composite are fabricated by compression molding technique with filler content ranging from 2.5-25 vol%. Effects of filler loading on various thermal properties like effective thermal conductivity ( keff), glass transition temperature ( Tg), coefficient of thermal expansion (CTE) and electrical property like dielectric constant (εc) of composites are investigated experimentally. In addition, physical properties like density and void fraction of the composites along with there morphological features are also studied. The experimental findings obtained under controlled laboratory conditions are interpreted using appropriate theoretical models. Results show that with addition of 25 vol% of Al2O3, keff of epoxy and PP improve by 482% and 498% respectively, Tg of epoxy increases from 98°C to 116°C and that of PP increases from −14.9°C to 3.4°C. For maximum filler loading of 25 vol% the CTE decreases by 14.8% and 26.4% for epoxy and PP respectively whereas the dielectric constants of the composites get suitably controlled simultaneously. POLYM. COMPOS., 36:102-112, 2015. © 2014 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

This work investigates a composite prepared with polyester and hexagonal boron nitride (hBN) in terms of the properties required in the material for microelectronics applications. The influence of filler loading and the surface treatment of hBN with a silane coupling agent (γ‐aminopropyl triethoxy silane) is studied. It has been observed that the silane‐modified hBN improves the compatibility and adhesion with the matrix as verified by SEM images. The experimental investigation reveals that the addition of hBN in polyester unwillingly rises the density, voids content, and water absorption rate. Though, the increment is limited with surface‐modified hBN. The material's mechanical properties improve with filler loading over a particular range of filler loading. The material's thermal conductivity and glass transition temperature increase with hBN content, whereas the coefficient of thermal expansion reduces. Polyester when filled with 40 wt% of the silane‐hBN, the thermal conductivity improves around six times that of unfilled polyester. The dielectric properties are marginally augmented with filler loading whereas, the increase in frequency results in the reduction of dielectric properties. It can be observed from the overall experimental analysis that the developed material can be used in different microelectronic applications. Highlights: A new class of composite is developed with polyester and raw/modified hBN.Composite with modified hBN shows improved physical/mechanical properties.Thermal properties of polyester improved appreciably with treated hBN.The dielectric properties of composites remain well within the range.The fabricated composites are recommended for microelectronics applications. [ABSTRACT FROM AUTHOR]