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Electron-induced electron yields of high-resistivity high-yield materials--ceramic polycrystalline aluminum oxide and polymer polyimide (Kapton HN)--were made by using a low-fluence pulsed incident electron beam and charge neutralization electron source to minimize charge accumulation. Large changes in the energy-dependent total yield curves and yield decay curves were observed, even for incident electron fluences of < 3 fC/[mm.sup.2]. The evolution of the electron yield as charge accumulates in the material is modeled in terms of electron recapture based on an extended Chung--Everhart model of the electron emission spectrum. This model is used to explain the anomalies measured in highly insulating high-yield materials and to provide a method for determining the limiting yield spectra of uncharged dielectrics. The relevance of these results to spacecraft charging is also discussed. Index Terms--Charging, dielectrics, electron, emission.

Electroless-plated copper improves the surface morphology of the AIN substrate, initially increased and then decreased the adhesion strength of copper after 150 degrees centigrades thermal storage and introduced stress concentrations in the interface leading to decrease in adhesive strength of the interface of Sn/Pb solder and electroless copper-plated AIN substrate. The presence of intermetallic compound leads to cracks along the interface and reduced adhesive strength.