| 摘要 |
PROBLEM TO BE SOLVED: To ensure an LSI mounting board of structural reliability even if an assembly operation is carried out on the surface of a mounting board under the same condition as usual, by a method wherein a stiffener which is of the same external shape with an LSI mounted on the mounting board and as thick as prescribed is provided to the rear surface of the mounting board with adhesive agent that is used for mounting the LSI on the front surface of the mounting board. SOLUTION: A silicon chip as a stiffener 4 of the same shape with an LSI 1 is bonded to the rear surface of a printed board 2 so as to be axially symmetrical to the LSI 1 about the printed board 2. The thermal expansion coefficient of the stiffener 4 is set near to that of silicon as much as possible. It is preferable that the stiffener 4 is identical to the LSI 1 both in thickness and in external shape. The stiffener 4 is fixed to the rear surface of the printed board 2 with adhesive agent 5. The adhesive agent 5 is used to bond the stiffener 4 to the printed board 2, and it is preferable that (stiffener 4 and adhesive agent 5) is soldered to the printed board 2 to exhibit the same behavior (generation of the offset stress in an opposite direction as to warpage) with the LSI 1 provided with an underfill 3. |
