| 摘要 |
PURPOSE:To improve the reliability of inter-layer connection and to make it possible to evaluate the amount of the inter-layer displacement by a method wherein a multi- layer printed circuit board is formed, and the electrical connection between an independent land corresponding to the inter-layer and other independent lands is inspected. CONSTITUTION:The central positions of the clearance holes H1-Hn bored on each inter-layer Q2, Q3 are formed on the center of the independent lands C1-Cn. Moreover, conductive foils 11, 2 are provided on the position corresponding to the independent land CO. If any displacement occurs, it deviates with respect to the central position of the independent land corresponding to the central position of the clearance hole. Thus, by providing a clearance hole for checking with a specified diameter on the central position of each independent land after lamination, the independent land CO is commonly connected regardless of presence of any displacement. If any displacement occurs, clearance holes H1-Hn with different diameter contact in accordance with the dimension of the amount of the displacement. Therefore, in the electrical connection test, the position of the independent land without electrical connection is confirmed to evaluate the amount of the displacement. |
