Electrodeposited copper foils having properties suitable for use as negative electrode current collectors in lithium-ion secondary batteries are disclosed. The copper foil has a yield strength in the range of 11 to 45 kg/mm.sup.2, and a difference in residual stress between the drum side and the deposited side of at most 95 MPa. Negative electrode current collectors for lithium-ion secondary battery, a lithium-ion secondary battery incorporating the negative electrode, and batteries containing the negative electrode current collector are also disclosed.

A surface-treated copper foil of the present disclosure includes a copper foil substrate, at least one surface of which has a surface treatment coat including at least a roughening-treated surface on which roughening particles are formed. Observation of a cross-section of the surface-treated copper foil with a scanning electron microscope shows that on a surface of the surface treatment coat, a standard deviation of the particle height of the roughening particles is 0.16 m or more and 0.30 m or less, and an average value of the ratio of the particle height to the particle width (particle height/particle width) of the roughening particles is 2.30 or more and 4.00 or less.

A joined body of a joining base material and a metal layer which, when the metal layer is joined to the base material, adhesion of the metal layer is high, variation in adhesion is small, and the joining can be performed inexpensively. The metal layer is joined to the joining base material via an intermediate layer coating formed on a joint surface of the base material. The intermediate layer coating is fused to the joint surface of the base material, and an anchor forming material that joins the metal layer by an anchor effect is dispersed and embedded in the intermediate layer coating; the anchor forming material partially protrudes outward from the intermediate layer coating, and is fused to the intermediate layer coating; and the metal layer is joined to a surface of the intermediate layer coating and a surface of the anchor forming material protruding outward from the intermediate layer coating.

A base material is provided. A first patterned circuit layer and a second patterned circuit layer are formed on a first surface and a second surface of the base material. A first insulation layer and a metal reflection layer are provided on the first patterned circuit layer and a portion of the first surface exposed by the first patterned circuit layer, wherein the metal reflection layer covers the first insulation layer, and a reflectance of the metal reflection layer is substantially greater than or equal to 85%, there is no conductive material between the first patterned circuit layer and the metal reflection layer. A first ink layer is formed on the first insulation layer before the metal reflection layer is formed.

A surface-treated copper foil according to exemplary embodiments includes a copper foil layer and a protrusion layer formed on one surface of the copper foil layer. Pores are formed inside the protrusion layer or around a boundary between the copper foil layer and the protrusion layer. Abnormal growth of the protrusions may be prevented through the pores and thus a bonding force with the insulation layer may be improved.

A copper foil for printed circuits is prepared by forming a primary particle layer of copper on a surface of a copper foil, and then forming a secondary particle layer based on ternary alloy composed of copper, cobalt and nickel on the primary particle layer. The average particle size of the primary particle layer is 0.25 to 0.45 m, and the average particle size of the secondary particles layer based on ternary alloy composed of copper, cobalt and nickel is 0.05 to 0.25 m. Provided is a copper foil for printed circuits, in which powder fall from the copper foil can be reduced and the peeling strength and heat resistance can be improved by forming a primary particle layer of copper on a surface of a copper foil, and then forming a secondary particle layer based on copper-cobalt-nickel alloy plating on the primary particle layer.

The present invention relates to a surface-treated copper foil, which has excellent adhesive strength with a resin substrate, shows low bending deformation after adhesion with a resin substrate, and is suitable as a high-frequency foil due to its low transmission loss, to a copper clad laminate comprising same, and to a printed wiring board.

Provided is a surface-treated copper foil in which in order to avoid failures of electronic parts by corrosion, a high bond strength between an electrolytic copper foil and a resin base material can be maintained even when the surface-treated copper foil is exposed to corrosive gases and microparticles, and a method for manufacturing the same. The surface-treated copper foil of the present invention comprises an electrolytic copper foil, a roughened layer covering at least one surface side of the electrolytic copper foil, and a rust preventive layer further covering the roughened layer, wherein the rust preventive layer is at least one surface of the surface-treated copper foil; the rust preventive layer comprises at least a nickel layer; and the thickness of the nickel layer is 0.8 to 4.4 g/m.sup.2 in terms of mass per unit area of nickel; and the noncontact roughness Spd of the rust preventive layer is 1.4 to 2.6 peaks/?m.sup.2 and the surface roughness RzJIS of the rust preventive layer is 1.0 to 2.5 ?m. The method for manufacturing the surface-treated copper foil forms the roughened layer having higher roughnesses than the noncontact roughness Spd and surface roughness RzJIS on one surface of the electrolytic copper foil, and thereafter forming the rust preventive layer meeting the predetermined condition.

A first and second patterned circuit layer are formed on a first surface and a second surface of a base material. A first adhesive layer is formed on the first patterned circuit layer. A portion of the first surface is exposed by the first patterned circuit layer. The metal reflection layer covers the first insulation layer and a reflectance thereof is greater than or equal to 85%, there is no conductive material between the first patterned circuit layer and the metal reflection layer, and the first adhesive layer is disposed between the first patterned circuit layer and the first insulation layer. A transparent adhesive layer and a protection layer are formed on the metal reflection layer. The transparent adhesive layer is disposed between the metal reflection layer and the protection layer. The protection layer comprises a transparent polymer. The light transmittance is greater than or equal to 80%.

A metal-clad laminate includes an insulating layer including a cured product of a resin composition, and a metal foil disposed on at least one principal surface of the insulating layer. The resin composition includes a thermosetting curing agent and a polyphenylene ether copolymer. The polyphenylene ether copolymer has an intrinsic viscosity ranging from 0.03 dl/g to 0.14 dl/g, inclusive. The intrinsic viscosity is measured in methylene chloride at 25 C. And the polyphenylene ether copolymer has, at a molecular terminal, a group represented by one of formula (1) and formula (2) at an average number of more than or equal to 0.8 and less than 1.5 per one molecule. Further, the metal foil includes a barrier layer containing cobalt on a first surface of the metal foil. The first surface is in contact with the insulating layer, and has a ten-point average roughness (Rz) of less than or equal to 2.0 m. In formula (1), R.sup.1 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms, and R.sup.2 represents an alkylene group having 1 to 10 carbon atoms. In formula (2), R.sup.3 represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

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