Bonding properties of epoxy-containing solder joints were investigated by a high temperature aging test. Specimens were prepared by bonding an R3216 standard chip resistor to an OSP-finished PCB by a reflow process with two basic types of solder (SAC305 & Sn58Bi) pastes and two epoxy-solder (SAC305+epoxy & Sn58Bi+epoxy) pastes. In all epoxy solder joints, an epoxy fillet was formed in the hardened epoxy, lying around the outer edge of the solder joint, between the chip and the Cu pad. In order to analyze the bonding characteristics of solder joints at high temperatures, a high-temperature aging test at 150°C was carried out for 14 days (336 h). After aging, the intermetallic compound Cu₆Sn₅ was found to have formed in the solder joint on the Cu pad, and the shear stress on the conventional solder joint was reduced by a significant amount. The reason that the shear force did not decrease much, even though in epoxy solder, was thatbecause epoxy hardened at the outer edge of the supported solder joints. Using epoxy solder, strong bonding behavior can be ensured due to this resistance to shear force，even in metallurgical changes such as those where intermetallic compounds form at solder joints.

In this paper, PZT piezoelectric ceramic specimens with 4 compositions (Zr/Ti=50/50, 53/47, 56/44, 58/42) in Pb(Zr,Ti)O3 system were fabricated. We studied effects of poling strength and thermal aging on the temperature characteristics of eletromechanical coupling factor k31 of the specimens, which were poled with the DC electric fields, 1.5, 2.5 and 3.5 kV/mm respectively and thermally aged for an hour at 200℃. The eletromechanical coupling factor k31 of the specimen with the composition Zr/Ti=53/47, nearest to the morphotropic phase boundary decreased the most greatly, irrelevant to the intensity of poling field, due to 1st thermal aging. And the temperature coefficient of eletromechaical coupling factor k31 was(-) in the ereragonal phase composition and (+) in the rhombohedral phase composition, which is reverse in the temperature coefficient of resonance frequency. It is interesting that eletromechanical coupling factor k31 of PZT ceramics is shown to be able to be able to increase as temperature increase in the interval -20~80℃.

The accelerated thermal aging of a CSPE were carried out for 0, 80.82, 161.63 days at 100℃, which are equal to 0, 40 and 80 years of aging at 50℃, respectively. The volume electrical resistivities of the seawater and freshwater flooding were measured through 3-terminal circuit diagram. The volume electrical resistivities of the 0y, 40y and 80y were 2.454×1013∼1.377×1014Ω?cm, 1.121×1013∼7.529×1013Ω?cm and 1.284×1013∼8.974×1013Ω?cm at room temperature, respectively. The dielectric constant of the 0y, 40y and 80y were 2.922∼3.431, 2.613∼3.285 and 2.921∼3.332 at room temperature, respectively. It is certain that the ionic (Na+, Cl-, Mg2+, SO4 2-, Ca2+, K+) conduction current was formed by the salinity of the seawater. The volume electrical resistivity of the cleaned CSPE via freshwater trends slightly upward with the number of dried days at room temperature. As a result, the CH2 component of thermally accelerated aged CSPE decreased after seawater and freshwater flooding for 5 days respectively, whereas the atoms such as Cl, O, Pb, Al, Si, Sb, S related with the conducting ion (Na+, Cl-, Mg2+, SO4 2-, Ca2+, K+) component increased relatively.