| 摘要 |
PROBLEM TO BE SOLVED: To provide a circuit board, capable of reducing a thermal stress applied to a ceramic substrate side of the circuit board, preventing cracks in the ceramic substrate from occurring and improving a reliability due to thermal stress. SOLUTION: In the circuit board in which a plurality of substrates (11) are stuck on a main board (17) with solder (19), the plurality of substrates (11) contain a substrate whose coefficient of thermal expansion is relatively smaller than that of the main board (17), and the plurality of boards (11) are constituted by pasting a ceramic substrate (12) and a substrate (13) which is located at the main board (17) side of the ceramic substrate (12) and is stronger than the ceramic substrate (12). Thereby, since the substrate (13), which is stronger than the ceramic substrate (12), is pasted at the main substrate (17) side of the ceramic substrate (12), the thermal stress applied to the ceramic substrate (12) side of the circuit substrate is reduced, and it is possible to prevent cracks from occurring at the ceramic substrate (12), and reliability of the circuit board caused by the thermal stress can be improved. COPYRIGHT: (C)2005,JPO&NCIPI |
