Patent attributes
Disclosed is a multilayer wiring board in which a copper foil is bonded by a thermocompression bonding onto an insulating layer having a bump for interlayer connection buried therein, and the copper foil and the bump are electrically connected to each other. The copper foil is provided with an oxide film having a thickness of 50 Å to 350 Å on a surface in contact with the bump and an insulating layer. In a manufacturing process, for example, an oxide coating of the copper foil to be subject to the thermocompression bonding is removed by acid cleaning, and then an oxide film having an appropriate thickness is formed by irradiating the copper foil with ultraviolet light. Consequently, reliability in electrical connection between the copper foil and the burn is adequately ensured, while achieving sufficient mechanical connection strength between the copper foil and the insulating layer.
