Low surface roughness electrolytic copper foil and process for producing the same

Abstract

A low-roughness electrolytic copper foil having a roughness Rz of 2.5 μm or less and having a tensile strength of 500 MPa or more at 25° C. measured within 20 minutes from the end of electrodeposition, and at the same time, from the end of electrodeposition The reduction rate of the tensile strength at 25° C. measured after 300 minutes has elapsed is 10% or less, and the elongation at 180° C. is 6% or more. A method for manufacturing electrolytic copper foil, the electrolytic copper foil uses a sulfuric acid-copper sulfate aqueous solution as an electrolyte, uses an insoluble anode made of titanium coated with a platinum metal element or an oxide element thereof, and a titanium anode opposite to the anode A cathode cylinder, a direct current is passed between the two electrodes, wherein hydroxyethyl cellulose, polyethyleneimine, sulfonates of active organic sulfur compounds, acetylene glycol and chloride ions are present in the above electrolyte.

Description

Technical field [0001] The present invention relates to a low-rough surface electrolytic copper foil and a manufacturing method thereof. The low-rough surface electrolytic copper foil has a small decrease in tensile strength with the passage of time or heat treatment, and has excellent elongation at high temperatures. Background technique [0002] As we all know, electrolytic foil is manufactured by the following method, that is, sulfuric acid-copper sulfate aqueous solution is used as the electrolyte, and an insoluble anode composed of titanium coated with a platinum group metal element or its oxide element is placed opposite to the anode The electrolyte is filled between the titanium cathode cylinders, while rotating the cathode cylinder at a constant speed, a direct current is applied between the two electrodes, thereby depositing copper on the surface of the cathode cylinder, and peeling the deposited copper foil from the surface of the cathode cylinder. Method of continuous ...

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Problems solved by technology

[0011] It can be considered that in the case of the manufacturing method of electrolytic copper foil disclosed in Japanese Patent No. 3313277, since the copper foil deposited on the cathode cylinder is made of very It is composed of small crystal particles, so the small crystal particles need to minimize the surface area at room temperature and move to a thermodynamically stable state. The interface of the crystal grain boundary can become the driving force for a recrystallization to occur at room temperature. After the crystal particles are coarsened , the tensile strength is significantly reduced

[0012] In addition, if the tensile strength of the electrodeposited copper foil is lowered, wrinkles are likely to be formed when the foil is thinned, or the workability of the laminated multilayer substrate is reduced.

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