Abstract: A method of producing an electrical conductor is described. The electrical conductor is made of an oxygen-free copper material having an oxygen content of not more than 50 ppm, wherein copper crystals constituting the copper material are giant crystals. These giant copper crystals are formed by heating the copper material in an inert atmosphere maintained at a temperature exceeding 800.degree. C. but below the melting point of copper for at least 15 minutes.

Abstract: A process for producing cooper foil laminated plates using rolled copper foils made of oxygen-free copper is described. The major feature of the present process is that in laminating a rolled copper foil on an insulating substrate, the rolled copper foil is ground or abraded and immediately brought into contact with water or steam to form a hydrate layer on the surface thereof. This hydrate layer increases the adhesion strength of the rolled copper foil to the insulating substrate through an adhesive, producing a copper foil laminated plate having an adhesion strength sufficiently high for practical use. Thus these copper foil laminated plates are very suitable for use in wiring of electronic devices.

Abstract: A process for manufacturing a copper-clad laminate which includes a rolled copper foil as a circuit conductive material comprising, introducing a rolled copper foil through a power supply/guide roller into an electrolyte so as to pass between two parallel electrodes which are disposed in the electrolyte. An AC, DC or a combination thereof is supplied to the power supply/guide roller and the electrodes to form an etched layer on either one or both sides of the rolled copper foil. An adhesive is applied to the etched layer and the resultant rolled copper foil is pressed with a substrate made of a synthetic resin put together to form a laminate.

Abstract: A method of producing an electrical conductor is described. The electrical conductor is made of an oxygen-free copper material having an oxygen content of not more than 50 ppm, wherein copper crystals constituting the copper material are giant crystals. These giant copper crystals are formed by heating the copper material in an inert atmosphere maintained at a temperature exceeding 800.degree. C., but below the melting point of copper for at least 15 minutes.