Abstract: [Problem] An object is to provide novel composite copper foils. [Means to solve the problem] A composite copper foil comprises a copper foil and a layer of metal other than copper, the metal layer being formed on at least a part of a surface of the copper foil, wherein at least a part of the composite copper foil has protrusions on a surface thereof, and each protrusion has a height of 10 nm or more but 1000 nm or less in a cross-section of the composite copper foil.

Abstract: The present invention is directed to provide novel composite copper components. For example, provided is a composite copper component including a copper oxide-containing layer formed on at least a portion of the surface of a copper component, in which when the surface of the composite copper component is bonded to a resin substrate by thermocompression, and the copper component is peeled off from the resin substrate after the thermocompression bonding, metal contained in the copper oxide-containing layer is transferred to the resin substrate.

Abstract: [Problem] An object is to provide novel composite copper foils. [Means to solve the problem] A composite copper foil comprises a copper foil and a layer of metal other than copper, the metal layer being formed on at least a part of a surface of the copper foil, wherein at least a part of the composite copper foil has protrusions on a surface thereof, and each protrusion has a height of 10 nm or more but 1000 nm or less in a cross-section of the composite copper foil.