Abstract: The present invention relates to a method for producing an electrolytic copper foil, the method enabling providing an electrolytic copper foil such that the electrical conductivity is 99% or more, the thickness is 10 ?m or less, a problem of a bend is suppressed, the front side and the rear side are flat, the tensile strength is 500 MPa or more, and the elongation percentage is 5.5% or more. The method for producing an electrolytic copper foil includes forming an electrolytic copper foil by using, as an electrolytic solution, a sulfuric acid-copper sulfate aqueous solution not containing a heavy metal other than a copper metal, using an insoluble anode and a cathode drum facing the insoluble anode, and passing a direct current between these electrodes, wherein, in the electrolytic solution, particular additives (A) to (E) are contained each in a particular amount, and the additive (D) and the additive (A) are each added in a ratio such that (D)/(A) is 0.2 to 0.7.

Abstract: The present invention relates to a method for producing an electrolytic copper foil, the method enabling providing an electrolytic copper foil such that the electrical conductivity is 99% or more, the thickness is 10 ?m or less, a problem of a bend is suppressed, the front side and the rear side are flat, the tensile strength is 500 MPa or more, and the elongation percentage is 5.5% or more. The method for producing an electrolytic copper foil includes forming an electrolytic copper foil by using, as an electrolytic solution, a sulfuric acid-copper sulfate aqueous solution not containing a heavy metal other than a copper metal, using an insoluble anode and a cathode drum facing the insoluble anode, and passing a direct current between these electrodes, wherein, in the electrolytic solution, particular additives (A) to (E) are contained each in a particular amount, and the additive (D) and the additive (A) are each added in a ratio such that (D)/(A) is 0.2 to 0.7.

Abstract: Disclosed is a copper foil for a negative electrode collector capable of simultaneously achieving high capacity and long life charge/discharge cycles in a secondary battery, wherein the front and back surfaces are of a uniform shape and, for example, the properties of a silicon active material of a lithium ion secondary battery are sufficiently realized; and a negative electrode using the copper foil. In one embodiment, a first roughened layer of metallic copper is formed by pulse cathode electrolysis roughening treatment on the surface of an untreated rolled copper foil base material of oxygen-free copper in a first roughening treatment tank (1) filled with a copper-sulphuric acid electrolyte (12), and a second copper-plate layer is formed on the surface of the first roughened layer by smooth copper plating treatment in a second copper plating treatment tank (2) filled with a copper-sulphuric acid electrolyte (22).

Abstract: Disclosed is a copper foil which has excellent high frequency characteristics and heat resistance, while achieving high heat-resistant adhesion to a resin substrate at the same time. Specifically disclosed is a heat-resistant copper foil which has a configuration wherein a first roughened surface layer which has been treated by a first roughening treatment by copper metal, a second roughened surface layer which has been treated by a second roughening treatment by copper metal, and a third treated surface layer which has been treated by a third treatment process by zinc metal are sequentially provided on one surface of an untreated copper foil.

Abstract: A copper foil with a resistance layer is provided, wherein the variation value is small when it is made into a resistance element, the adhesion with the resin substrate to be laminated with is able to be sufficiently maintained, which has an excellent characteristics as a resistance element for a rigid and a flexible substrate. A copper foil with a resistance layer of the present invention comprises a copper foil on one surface of which a metal layer or alloy layer is formed from which a resistance element is to be formed, the surface of the metal layer or alloy layer being subjected to a roughening treatment with nickel particles. A method of production of a copper foil with a resistance layer of the present invention comprises: forming a resistance layer of phosphorus-containing nickel on a matte surface of an electrodeposited copper foil having crystals comprised of columnar crystal grains wherein a foundation of the matte surface is within a range of 2.5 to 6.

Abstract: A method of surface-roughening a copper foil by subjecting at least one side of the copper foil to electro-plating using an alternating current, wherein a sulfuric acid bath or a sulfuric acid-copper sulfate bath is used as an electrolyte.

Abstract: Disclosed is a both-side roughened copper foil with a protection film, comprising a metal foil as soft as or softer than copper, or an organic type film having a melting point equal to or higher than a lamination temperature, laminated on one side of a copper foil with both sides roughened, the metal foil or organic film being continuously or continually bonded or adhered to the copper foil. It is possible to protect the ruggedness on the roughened surface at the time the both-side roughened copper foil is cut, packed, transported or stacked on another both-side roughened copper foil, simplify the press molding work, and improve the production efficiency particularly in the step of fabricating a copper-clad laminated board for a printed circuit board as well as the quality of the acquired copper-clad laminated board.

Abstract: A copper foil for an inner layer circuit of a multi-layered printed circuit board, which comprises a black metal plated layer formed on at least the rough surface which becomes a surface of an inner layer circuit of a copper foil having both sides roughened in advance, in order to enhance the bonding strength to a prepreg, make it safe from haloing and facilitate optical checking of the copper foil.

Abstract: A method for preparing a copper-clad laminated board for a printed circuit board which comprises: (a) preparing a prepreg by permeating a thermosetting resin into a fabric and then drying the resulting material to a half-hardened state, (b) laminating a both-side roughened copper foil on both sides or one side of the prepreg or a plurality of prepregs bonded together, (c) placing the resulting laminate from step (b) between both press plates of a press machine, (d) placing a polyamide film having a melting point equal to or higher than 170.degree. C. between the exposed side of the both-side roughened copper foil of the laminate and a press plate, (e) pressing the laminate with the press plates of the press machine at a temperature of 170.degree. C. or higher, a pressure of 10 kgf/cm.sup.2 or higher for a time of 60 minutes or longer, (f) separating the laminate from the press machine and (g) peeling the polyamide film from the laminate to obtain the copper-clad laminated board.