Conventional test methods to evaluate the quality of glass passivation overcoats on semiconductor devices are generally inadequate and/or destructive. We have recently devised three new methods that overcome these problems: (1) Sequential selective chemical etching of metal/dielectric structures to detect buried, latent, or partial defects as a function of dielectric layer depth. (2) Electrophoretic cell decoration with uv phosphor particles suspended in an insulating liquid, the sample forming one electrode of the cell. (3) Electrostaticcorona charging to selectively deposit surface ions from a high‐voltage dc discharge on the insulating surfaces of the samples, followed by placing of the charged sample in a suspension of charged carbon black particles in an insulating liquid; depending on the polarity of the ions the particles can be deposited on the insulator surface or at the defect sites. The etching method is most suitable in process research studies, and the electrophoretic technique for demarcating relatively large defects. The corona‐decoration method, coupled with automated instrumental readout based on measuring the reflected‐light intensity, is ideal for routine testing of devices because it is fast, simple, sensitive, and nondestructive to devices such as glass‐passivated MOS and linear bipolar silicon‐integrated circuits.