The potential of an innovation for establishing a simultaneous mechanical, thermal, and electrical connection between two metallic surfaces without requiring a prior time-consuming and expensive surface nanoscopic planarization and without requiring any intermediate conductive material has been explored. The method takes advantage of the intrinsic nanoscopic surface roughness on the interconnecting surfaces: the two surfaces are locked together for electrical interconnection and bonding with a conventional die bonder, and the connection is stabilized by a dielectric adhesive filled into nanoscale valleys on the interconnecting surfaces. This “nano-locking” (NL) method for chip interconnection and bonding is demonstrated by its application for the attachment of high-power GaN-based semiconductor dies to its device substrate. The bond-line thickness of the present NL method achieved is under 100 nm and several hundred times thinner than those achieved using mainstream bonding methods, resulting in a lower overall device thermal resistance and reduced electrical resistance, and thus an improved overall device performance and reliability. Different bond-line thickness strongly influences the overall contact area between the bonding surfaces, and in turn results in different contact resistance of the packaged devices enabled by the NL method and therefore changes the device performance and reliability. The present work opens a new direction for scalable, reliable, and simple nanoscale off-chip electrical interconnection and bonding for nano- and micro-electrical devices. Besides, the present method applies to the bonding of any surfaces with intrinsic or engineered surface nanoscopic structures as well.

With the aim of reducing the insulation faults in GIS and achieving the purpose of GIS device miniaturization, it is very important to develop a new type insulation material. In this paper, the micro-nano AI203/Epoxy composites were proposed, and its dielectric breakdown strength was investigated. Nano-fillers and micro-fillers (u-AI203 with a purity of 99.9%, particle size range at 12-21 J.lm for micro fillers, and average particle size with 30 nm for nano fillers)were dispersed in the epoxy resin with shear force and ultrasonic vibration. The specimens were produced by a curing reaction with the hardener. Six kinds of material were prepared for this investigation, which were neat epoxy, nano-composite (loaded with 5 wt% nano-Al203 fillers), nano-composite (loaded with 5 wt% nano-Ti02 fillers),micro-composite (loaded with 65 wt% micro-Al203 fillers), nano-micro-mixture-composites (loaded with 2 wt% nano-Al203 fillers and 63 wt% micro-Al203 fillers), nano-micro-mixture-composites (loaded with 2 wt% nano-Ti02 fillers and 63 wt% micro-Al203 fillers).Dispersion of the micro and nano AI203 in the epoxy resin was observed through SEM, and thermal behavior was analyzed with Thermo-Gravimetric Analysis (TGA) and differential scanning calorimeter (DSC). The dielectric constant and dielectric loss were measured by broadband dielectric spectrum test facility. Dielectric breakdown experiments were carried out through the sphere-plate sample-sphere configuration under AC voltage.

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