| 摘要 |
PROBLEM TO BE SOLVED: To improve the bonding strength between a solder ball and a PCB by forming first and second conductive pads on first and second pattern layers, respectively, and providing a mounting groove for the solder ball having a depth substantially equal to the spacing between the first and second pattern layers. SOLUTION: A circuit board, on which a semiconductor chip 2 is mounted and which includes a first pattern layer 24 and a second pattern layer 26 having predetermined conductive patterns formed thereon, respectively, is provided. Also, a plurality of solder balls 5, which are electrically connected with the semiconductor chip 2 through the predetermined conductive patterns and are adhered to the bottom surface of the circuit board, are provided. Particularly, a first conductive pad 22 is formed on the first pattern layer 24 of the circuit board on which the plurality of solder balls 5 are adhered, and a second conductive pad 23 is formed on the second pattern layer 26. Moreover, a mounting groove for the solder balls 5 having a depth substantially equal to the spacing between the first pattern layer 24, and the second pattern layer 26 is provided. Thus, the bonding strength between the solder balls 5 and the PCB is improved. |
