| 摘要 |
PURPOSE:To provide a method of manufacturing a board of high reliability, wherein an insulating layer can be flattened by removing its projections and the board can be easily enhanced in number of layers. CONSTITUTION:A conductor pattern 4 is formed on a board 6, an insulating layer 5 is formed on the conductor pattern 4, a mask is provided to the end face of the board 4 protruding to cut off laser ray 3, laser ray is made to irradiate in parallel with the board 6, and the part of the insulating layer 5 protruding above the mask 7 is removed by laser ray 3 transmitted through the mask 7. Or, a groove sloped by a prescribed angle is provided to the one side of the board, an end dummy pattern is formed on the part of the board which confronts the slope of the groove protruding above a conductor pattern to shade laser ray, a slope dummy pattern is formed on the slope of the groove protruding above the end dummy pattern to reflect laser ray. Laser ray is made to irradiate the slope dummy pattern to obtain the reflected laser ray parallel with the board, and an insulating layer protruding above the end dummy pattern is removed by the reflected laser ray concerned. |
