| 摘要 |
PURPOSE:To make it possible to check every portion of a component-mounted substrate in a short time by the use of an inspection board made of a liquid crystal board and a deflecting board and arranged on the board opposite to each other and a signal generating means for producing a signal that represents two-dimensional variations in the state of the liquid crystal. CONSTITUTION:When a component-mounted board 1 is examined, an inspection board 2 made by the lamination of a liquid crystal board and a deflecting board together is closely arranged above the board 1 with a certain distance kept between them. When an electric circuit of the board 1 is actuated, an electric field instantaneously or continuously develops around components on the board 1 and printed interconnections, thereby causing variations 3 to appear in the state of liquid crystal in accordance with the electric field. The abnormality of the board 1 is determined by observing the variations 3 in the state of the liquid crystal. Microcurrents flowing between electrodes 4 and 5 change in accordance with variations in the state of the liquid crystal. Upon detection of such changes in the microcurrents, a control section 6 produces a matrix signal representing two-dimensional variations in the state of the liquid crystal. This signal is processed, and then shown on a display 7. |
