Abstract: A method of making a printed circuit board includes a step of providing a double-sided plate that is an insulating substrate having conductive layers on respective surfaces thereof, a first coating step of coating a first surface of the double-sided plate with a first photosensitive resin film, a second coating step of coating a second surface of the double-sided plate with a second photosensitive resin film, a first exposure step of exposing the photosensitive resin film coating the first surface after the first and second coating steps, and a second exposure step of exposing the photosensitive resin film coating the second surface after the first exposure step, wherein a maximum depth of a depression in an outermost surface of the second photosensitive resin film used in the second exposure step is less than 1.0 ?m.

Abstract: A method of making a printed circuit board includes a step of providing a double-sided plate that is an insulating substrate having conductive layers on respective surfaces thereof, a first coating step of coating a first surface of the double-sided plate with a first photosensitive resin film, a second coating step of coating a second surface of the double-sided plate with a second photosensitive resin film, a first exposure step of exposing the photosensitive resin film coating the first surface after the first and second coating steps, and a second exposure step of exposing the photosensitive resin film coating the second surface after the first exposure step, wherein a maximum depth of a depression in an outermost surface of the second photosensitive resin film used in the second exposure step is less than 1.0 ?m.

Abstract: The substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties, and a metal layer stacked on at least one surface of the base film, in which the base film includes a portion where a transition metal in group 10 of the periodic table is present. The transition metal in group 10 is preferably nickel or palladium. The portion where the transition metal in group 10 is present preferably includes a region having an average thickness of 500 nm and extending from an interface with the metal layer.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a base film having an insulating property, and a metal layer formed on at least one surface side of the base film. In the substrate for a printed circuit board, a plurality of fine particles are disposed between the base film and the metal layer, and the fine particles are formed of a metal the same as a main metal of the metal layer or formed of a metal compound of the main metal. The fine particles preferably have an average particle size of 0.1 nm or more and 20 nm or less. The fine particles are preferably formed of a metal oxide or a metal hydroxide. The fine particles are preferably present between the base film and the metal layer so as to form a layer. The metal layer preferably includes a metal grain layer formed by firing metal nanoparticles.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties and a sintered layer formed of a plurality of metal particles, the sintered layer being stacked on at least one surface of the base film, in which a region of the sintered layer extending from an interface between the sintered layer and the base film to a position 500 nm or less from the interface has a porosity of 1% or more and 50% or less.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties and a sintered layer formed of a plurality of metal particles, the sintered layer being stacked on at least one surface of the base film, in which a region of the sintered layer extending from an interface between the sintered layer and the base film to a position 500 nm or less from the interface has a porosity of 1% or more and 50% or less.

Abstract: A substrate for a printed circuit board according to an embodiment of the present invention includes a base film having an insulating property, and a metal layer formed on at least one surface side of the base film. In the substrate for a printed circuit board, a plurality of fine particles are disposed between the base film and the metal layer, and the fine particles are formed of a metal the same as a main metal of the metal layer or formed of a metal compound of the main metal. The fine particles preferably have an average particle size of 0.1 nm or more and 20 nm or less. The fine particles are preferably formed of a metal oxide or a metal hydroxide. The fine particles are preferably present between the base film and the metal layer so as to form a layer. The metal layer preferably includes a metal grain layer formed by firing metal nanoparticles.

Abstract: The substrate for a printed circuit board according to an embodiment of the present invention includes a base film having insulating properties, and a metal layer stacked on at least one surface of the base film, in which the base film includes a portion where a transition metal in group 10 of the periodic table is present. The transition metal in group 10 is preferably nickel or palladium. The portion where the transition metal in group 10 is present preferably includes a region having an average thickness of 500 nm and extending from an interface with the metal layer.