Resistor forming substrate and a manufacturing method thereof

Resistor forming substrate includes a first insulating layer, a first wiring formed on the first surface of the first insulating layer, and a thin film resistor layer formed on the second surface of the first insulating layer, the has a first via hole conductors, the. First via hole conductor, through the first insulating layer, it is electrically connected to the first wiring and the thin film resistor layer. Main component of the thin film resistor layer is nickel. First via hole conductor, a metal part having a low melting point metal and a refractory metal, and a paste resin portion, has. Low melting point metal comprises tin and bismuth, the melting point is less than 300 degrees. Refractory metal comprises at least one of copper or silver, a melting point of 900 degrees or more. First via hole conductors, and a paste resin part, in both the metal part is in contact with the thin film resistor layer.