WIRING SUBSTRATE AND MANUFACTURE THEREOF

PROBLEM TO BE SOLVED: To provide a wiring substrate which can prevent its deformation to obtain a high coplanarity for a surface of a substrate and electrodes by suitably providing protrusions on the substrate for preventing sag-deformation of the backside of the substrate due to the softening of the substrate when burned. SOLUTION: A plurality of island-like burned protrusions 11 having a height Ts nearly corresponding to a thickness Tp of external connection pads 6 are provided on an area of a backside 5 of a substrate 1 where the pads 6 are not present and which corresponds to an area of a surface 2 of the substrate where group of chip connection electrodes 3 present. Since the protrusions 11 are provided not only near a peripheral edge of the area corresponding to the electrode presence area but also at sites inside of the vicinity of the peripheral edge, sag-deformation in burning the substrate can be effectively prevented.