| 摘要 |
PURPOSE: To control the dislocation of a pad from a pin as an input/output lead by a method wherein a second dummy pad larger than a first pad is formed on a mounting board, a bump and the second pad are mounted on the board and the pin for a package is mounted. CONSTITUTION: A PGA package 1 comprises 288 pins 2. A protrusion part 0.8mm high is formed in the central part of the package 1, and solder bumps 3 for dummies are formed additionally. On the other hand, second pads 7 larger than first pads 6 are formed on a mounting board 5. Then, the bumps 3 are bonded to, and mounted on, the pads 7, and the pins 2 on the package 1 are mounted on the mounting board 5. Thereby, thanks to the self-alignment effect of solder in the dummy pad parts 7, an alignment operation is performed easily, and a stress concentrated on input/output pins can be relaxed. |
