| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent cracking in a solder ball formed on a land, and then increase shear strength of the solder ball. SOLUTION: A printed wiring board 10 has a land 12 formed in a wiring pattern 11 corresponding to the forming position of a solder ball, a pattern protective film 13 having an opening 13a which opens at the forming position of the land 12. In this printed wiring board 10, the diameter of the opening 13a of the pattern protective film 13 is set larger than the outer diameter of the land 12, and a reinforcement pattern 14 is extended in the outward direction from the outer peripheral edge of the land 12. Moreover, the extended terminal of the reinforcement pattern 14 is covered with the pattern protective film 13.</p> |
