| 摘要 |
PURPOSE:To effect a visual inspection of the circuit pattern condition easily as well as highly accurately and with a less fatigue, by overlaying a light-transmitting plate colored in a purple color on a printed-wiring board. CONSTITUTION:A light-transmitting plate, such as a transparent plastic film colored in a purple color, is overlaid on a printed-wiring board having a circuit pattern formed thereon, to visually inspect the circuit pattern on the printed- wiring board through the light-transmitting plate. Thus, the color difference between an electrical laminate of the printed-wiring board of brown, orange, yellow or the like and the copper circuit pattern of copper is made apparent thanks to the purple color of the light-transmitting plate. Thereby, the circuit pattern shape is made clear to facilitate the visual inspection. In inspection, if light is applied from the lower or upper side or both the upper and lower sides of the printed-wiring board, the degree of accuracy is further increased. |
