Abstract: The present invention provides a circuit substrate which has a substrate including a first surface and a second surface opposite to the first surface. A first and a second conductor patterns are formed on the first and the second surface respectively. The second surface has larger surface roughness than the first surface. When the circuit substrate is mounted on another substrate, it is mounted to the other substrate via the second surface. The circuit substrate is capable of mounting a device or being mounted on another substrate to form an apparatus.

Abstract: The present invention provides a packaged substrate which has a superior positioning accuracy of wiring formed on a circuit substrate made of ceramics, and a conductive pattern with a thick film and yet a fine pattern. On a surface of flexible base member made of plastic, fine grooves are formed in a pattern corresponding to a first conductive pattern so that a cavity face is produced. Conductive paste is filled and into the grooves on this cavity face, and then dried. The cavity face and a circuit substrate are pasted with each other by applying predetermined heat and pressure. A pattern of the dried conductive paste is transcribed onto the circuit substrate, and then the first conductive pattern is formed by firing. A first ball solder is coupled with a second conductive pattern which is coupled to the first conductive pattern through an electrode in a through-hole of the circuit substrate.