Abstract: A method is provided for detecting cracks and other imperfections in a solar cell, which includes scanning a narrow light beam back and forth across the cell in a raster pattern, while monitoring the electrical output of the cell to find locations where the electrical output varies significantly. The electrical output can be monitored on a television type screen containing a raster pattern with each point on the screen corresponding to a point on the solar cell surface, and with the brightness of each point on the screen corresponding to the electrical output from the cell which was produced when the light beam was at the corresponding point on the cell. The technique can be utilized to scan a large array of interconnected solar cells, to determine which ones are defective.

Abstract: A method for analyzing the radiation sensitivity of an integrated circuit to determine the components, particularly tansistors, of greatest radiation sensitivity, including the application of a narrow radiation beam to portions of the circuit, as by applying the beam of a scanning electron microscope, so the radiation is applied to only one transistor at a time. The circuit is operated under normal bias conditions during the application of radiation in a dosage that is likely to cause malfunction of at least some transistors, while the circuit is monitored for failure of the irradiated transistor. If the irradiated transistor does not fail, then the other transistors are irradiated one at a time. When a radiation sensitive transistor is found, then the radiation beam is further narrowed and, using a fresh integrated circuit, a very narrow beam is applied to different parts of the transistor such as its junctions to locate the points of greatest sensitivity.