| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a circuit board device that relaxes elongation and stress of a printed board and a ceramic substrate due to temperature change, and has high bonding reliability of a BGA mounting structure. <P>SOLUTION: A thermal stress-absorbing member 3 made of metal having a coefficient of thermal expansion between coefficients of thermal expansion of the ceramic substrate 1 and printed board 2 is joined between the both, and is disposed so as to surround a solder bump 4, thereby a junction structure has high bonding reliability while relaxing thermal stress generated at a BGA junction part due to the solder bump 4. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
