| 摘要 |
PROBLEM TO BE SOLVED: To provide a multilayered printed wiring board in which thickness of the prepreg layers that are laminated between outer and inner wiring layers can be inspected simply by a visual means. SOLUTION: The wiring board is provided with a double sided substrate 11 on both sides of which wiring layers L2 and L3 having a specified pattern for each are formed, respectively. At least one of the two wiring layers, L2, is specified as an inner wiring layer, above which an outer wiring layer L1 is formed, laminating prepreg layers 12 and 13 between the layer L1 and the layer L2. A pattern D1 for prepreg layer detection is formed at a specified position of the surface of the inner wiring plane, and a window W1 is formed in the outer wiring layer so that pattern D1 can be observed visually through prepreg layers 12 and 13. |
