Such a metal foil is provided that a release layer is provided on a metal foil to enable physical release of a resin substrate, to which the metal foil is adhered, and thereby in the step of removing the metal foil from the resin substrate, the metal foil can be removed with good cost without damaging the surface profile of the metal foil transferred to the surface of the resin substrate, and also resins having different resin components can be adhered with good adhesion. A metal foil containing, on at least one surface of the metal foil, surface unevenness having a root mean square height Sq of from 0.25 to 1.6 m.

Embodiments of the present disclosure are directed towards techniques and configurations for formation of a dielectric with a smooth surface. In one embodiment, a method includes providing a dielectric with first and second surfaces, a conductive feature formed on the first surface, and a laminate applied to the second surface, curing the second surface while the laminate remains applied, and removing the laminate. Other embodiments may be described and/or claimed.

The present invention provides a surface-treated copper foil capable of imparting the profile shape of the substrate surface after removal of the copper foil, the profile shape maintaining fine wiring formability and achieving satisfactory adhesion of electroless copper plating coating. The present invention also provides a resin substrate provided with a profile shape of the surface maintaining fine wiring formability and achieving satisfactory adhesion of electroless copper plating coating. The surface-treated copper foil of the present invention is a surface-treated copper foil having a surface-treated layer formed on a copper foil, and the surface roughness Sz of the surface of the surface-treated layer is 2 to 6 m.

There is provided a method for manufacturing a printed wiring board that effectively suppresses pattern failure and is also excellent in fine circuit forming properties. This method includes: providing an insulating substrate including a roughened surface; performing electroless plating on the roughened surface of the insulating substrate to form an electroless plating layer less than 1.0 m thick having a surface having an arithmetic mean waviness Wa of 0.10 m or more and 0.25 m or less and a valley portion void volume Vvv of 0.010 m.sup.3/m.sup.2 or more and 0.028 m.sup.3/m.sup.2 or less; laminating a photoresist on the surface of the electroless plating layer; performing exposure and development to form a resist pattern; applying electroplating to the electroless plating layer; stripping the resist pattern; and etching away an unnecessary portion of the electroless plating layer to form a wiring pattern.

A circuitized substrate which includes a conductive paste for providing electrical connections. The paste, in one embodiment, includes a metallic component including nano-particles and may include additional elements such as solder or other metal micro-particles, as well as a conducting polymer and organic. The particles of the paste composition sinter and, depending on what additional elements are added, melt as a result of lamination to thereby form effective contiguous circuit paths through the paste. A method of making such a substrate is also provided, as is an electrical assembly utilizing the substrate and including an electronic component such as a semiconductor chip coupled thereto.

A multilayer rigid flexible printed circuit board including a flexible region including a flexible film having a circuit pattern formed on one or both surfaces thereof and a laser blocking layer formed on the circuit pattern and a rigid region formed adjacent to the flexible region and including a plurality of pattern layers on one or both surfaces of extended portions extended to both sides of the flexible film of the flexible region, and a method for manufacturing the same.

The present invention provides a multilayer rigid flexible printed circuit board including: a flexible region including a flexible film having a circuit pattern formed on one or both surfaces thereof and a laser blocking layer formed on the circuit pattern; and a rigid region formed adjacent to the flexible region and including a plurality of pattern layers on one or both surfaces of extended portions extended to both sides of the flexible film of the flexible region, and a method for manufacturing the same.

There is provided a carrier-attached metal foil including a carrier having a first surface and a second surface facing each other, and a side face connected to the first surface and the second surface; a release layer provided on the first surface of the carrier; and a metal layer having a thickness of 0.01 m or more and 4.0 m or less provided on the release layer. The metal layer extends from the first surface to the side face of the carrier so that at least a portion of the side face is covered by the metal layer. The carrier has an uneven region having a developed interfacial area ratio Sdr of 3% or more and 39% or less on the side face or the side face and the first surface, and the uneven region encompasses a region of the side face covered by the metal layer.