| 摘要 |
PURPOSE:To obtain the substrate for mounting of the semiconductor elements in high density by a method wherein the substrate is made of the material the same with the semiconductor elements to remove the difference between the coefficients of thermal expansion. CONSTITUTION:When a comparatively soft polymer of polyimide, etc., is used as an insulating film for construction of a multilayer wiring on the Si substrate, concentration of stress at the connecting part of a chip and the substrate can be prevented. The polymer has the larger coefficient of thermal expansion than Si usually, while when it is formed in a thin film, behavior of thermal expansion thereof nearly follows that of Si. Therefore even when the Si chip is connected electrically to the wiring on the polymer film formed on the Si substrate using solder balls, break off of the connecting part to be caused according to thermal expansion is not generated. Accordingly, formation of the chip in a large area, provision of connecting pins in high density can be facilitated. |
