| abstract |
For the purpose of providing a semiconductor element built-in type multilayered circuit board in which a semiconductor element is closely joined to a recess of an insulating substrate to effectively disperse heat generated from the semiconductor element through the insulating substrate at a working temperature region of the semiconductor element circuit board, to surely conduct an electrical connection of an electronic part such as semiconductor element or the like in a short wiring and to enable the high density mounting of semiconductor elements, miniaturization and increase of working speed, there is proposed a semiconductor element built-in type multilayered circuit board formed by laminating a plurality of semiconductor element built-in type boards each comprising an insulating substrate and a semiconductor element accommodated in a recess formed therein, characterized in that a difference between a linear expansion coefficient of the insulating substrate and a linear expansion coefficient of the semiconductor element in a temperature zone of 20-300° C. is less than 1×10 −5 /K. |