| 摘要 |
PROBLEM TO BE SOLVED: To stop the progression of cracks due to heat deformation of bumps and increase reliability of connection between a pad electrode and bumps in a ball grid array(BGA), having an IC chip on the front surface and a pad electrode on the back surface of an interposer to be electrically connected with external terminals via the bumps bonded on the pad electrode. SOLUTION: In this BGA 100, recesses 40 are provided in the back surface 12 of an interposer 10. A pad electrode 16 is formed as a film which continuously covers the base, the internal side surface 42 and the opening edge 44 of the recesses 40. A solder bump 50 is bonded with the pad electrode 16 at the base 43, the internal side surface 42 and the opening edge 44 of the recesses 40. |
