Metal-based circuit board

Abstract

A metal-based circuit board, which reduces the influence of thermal expansion, is provided having a structure where an insulating layer A having a large coefficient of thermal expansion is sandwiched between insulating layers B having a small coefficient of thermal expansion. Such a structure allows the insulating layers B to contract and expand so as to suppress contraction and expansion of the insulating layer A and thereby reduce the stress in the direction of negating the stress. As a result, while warpage or distortion is suppressed to be minimal, the bonding strength of the upper and the lower layer is maintained, and degree of freedom for circuit design is not impaired, thereby providing a highly reliable circuit structure.

Dependencies are inferred from the claim text.