A wiring apparatus including a substrate, a via-hole penetrating the substrate, a buffer layer formed on an inner surface of the via-hole, and a plating layer filling filing the via hole inside of the buffer layer. When the wiring apparatus is applied to a protecting cap for device package, a difference in thermal expansion coefficient generated between the substrate and the plating layer can be compensated, thereby preventing damage to the packaging substrate even upon application of thermal impact. Methods for fabricating the wiring apparatus and a protecting cap for a device package using the above wiring processes are also disclosed.