In this paper, the technique of drilling process with picosecond(ps) laser is studiedinAl2O3 ceramics. The defocus method is used to drill the ceramic slice, which is able to improve thedrilling ratio of depth to diameter.It is found out that the best location ofthis ps-laser is about0.15mm under the lower surface of workpiece,demonstrating the difference from nanosecond(ns)-laser machinein the respective ofdefocusing.The impact of the power and the processing speed isinvestigated on the quality of the drilling. For ps-laser machine,a smaller and high qualitythrough-holeis achievable by increasing the power of laser and reducing the speed of process, withthe ratio of depth to diameter from 3.12 to 4.27.The ratio can be further increased upto 6.25,throughoptimization of these three parameters: defocusing amount, laser power and laser processing speed.

A laser drilling technique named the nested-circle method is introduced in this work, in the respect of short-pulse laser processing.it is found that, as the power increases, the depth to diameter ratio of the hole will increase and the minimum number of circles can be set drilled hole reliably is reduced. Further studies have been carried out on the effect of the number of circles in the nested-circle method. Keys of settings the nested-circle method parameters—Outer circle diameter ‘D1’, Inner circle diameter ‘D2’, The Number of circles ‘R’—have been found out.

The long-term stability of microelectronic devices is crucial for their practical applications. However, silver particles in the conductive adhesive can migrate easily under certain conditions, resulting in failure of the devices. In this investigation, the migration of silver particles has been studied by using the devices of Plate-capacitors in the cavity that are bonded with conductive adhesives. The experimental results show that the migration of silver particles occurred in the condition of humid environment with an applied direct current (DC) electric field. Also, the migration of silver particles under a variety of humidity was analyzed, and the reasons causing the failure of the devices were demonstrated.