| 摘要 |
PROBLEM TO BE SOLVED: To form all lead wires on a single-layer printed wiring board by forming, a land on the printed wiring board at positions, corresponding to each of pins of a grid array package. SOLUTION: Virtual closed curves 10a, 10b, 10c, and 10d are formed in a nested state, on a base board 1 of a grid array package 5. Joining lands 2 are arrayed on the respective virtual closed curves 10a, 10b, 10c, and 10d, and distances between the joining lands 2 on the virtual closed curves 10a, 10b, 10c, and 10d are a, b, c, and d respectively, and the distance therebetween becomes larger from the inside virtual closed curves 10a toward the outside virtual closed curves 10d, that is, a<b<c<d. |
