Patent attributes
A composite multi-layer substrate comprising a flat plate-like core member formed of a material having an excellent electric conductivity, an excellent heat conductivity, and a high rigidity, a front resin layer and a rear resin layer covering at least the front and rear surfaces of the core member, and a bottomless hole formed in the core member through the front and rear sides of the core member, wherein an electronic component is installed in the bottomless hole, whereby since the strength of the composite multi-layer substrate can be assured by the rigidity of the core member, conventional prior art glass cloth can be eliminated, deterioration in the electric characteristics caused by ion migration can be avoided and will result in reduced production cost.