| 摘要 |
<p>PURPOSE:To simplify mounting and reduce cost by directly connecting a chip and a substrate through a plurality of films C of intermediate coefficient of thermal expansion between a film A and a film B with the same coefficient of thermal expansion as that of chip and the substrate. CONSTITUTION:A multilayer film 5 is formed of a film A with the same coefficient of thermal expansion as that of a chip 1, a film B with the same coefficient of thermal expansion as that of a substrate, and a plurality of films C with an intermediate coefficient of thermal expansion and the chip 1 and the substrate 3 are directly connected through a pin 9. When power is supplied to the chip 1 through the pin 9, the chip 1 expands thermally but no shear stress occurs in a solder ball 2 since the film A equally expands. Also, no shear stress occurs in a pin pad 10 by the film B for expansion of the substrate 3 and the difference in coefficient of thermal expansion between the films A and B is relaxed through the film C. It allows the chip and the substrate to be connected directly, simplifies mounting, and then reduce cost.</p> |
