Provided is a copper foil provided with a carrier in which the laser hole-opening properties of the ultrathin copper layer are good and which is suitable for producing a high-density integrated circuit substrate. A copper foil provided with a carrier having, in order, a carrier, an intermediate layer, and an ultrathin copper layer, wherein the specular gloss at 60 in an MD direction of the intermediate layer side surface of the ultrathin copper layer is 140 or less.

A manufacturing method of an interposed substrate is provided. A photoresist layer is formed on a metal carrier. The photoresist layer has plural of openings exposing a portion of the metal carrier. Plural of metal passivation pads and plural of conductive pillars are formed in the openings. The metal passivation pads cover a portion of the metal carrier exposed by openings. The conductive pillars are respectively stacked on the metal passivation pads. The photoresist layer is removed to expose another portion of the metal carrier. An insulating material layer is formed on the metal cattier. The insulating material layer covers the another portion of the metal carrier and encapsulates the conductive pillars and the metal passivation pads. An upper surface of the insulating material layer and a top surface of each conductive pillar are coplanar. The metal carrier is removed to expose a lower surface of the insulating material layer.

A conductive grid formation system, apparatus, and related methods may include a drum having a conductive surface, an insulation layer coating said surface, and a grid pattern formed in the insulation layer to expose portions of the conductive surface. The drum surface may be rotated into and out of a chemical bath, such that a metallic grid is electrodeposited in the exposed portions of the conductive surface. A polymer sheet may be laminated to the surface of the drum and then removed, such that the metallic grid attaches to the polymer sheet and is removed with the polymer sheet. Heat, pressure, and/or adhesive may be utilized in various steps of the process, to facilitate preferential adhesion of the metallic grid to the polymer sheet.

A carrier-attached copper foil having good circuit formability is provided. The carrier-attached copper foil has a carrier, an intermediate layer and an ultra-thin copper layer in this order, the average grain size of crystal grains that form the ultra-thin copper layer is 1.05 to 6.5 m, and a ten point average roughness Rz of a surface on a side of the ultra-thin copper layer is 0.1 to 2.0 m.

The present invention has the following configuration. The present invention relates to a low-loss flat cable signal line for an ultra-high frequency, wherein the signal line plated, by a manufacturing method using an electroplating bath, on a micro circuit pattern part formed in a cylindrical circuit mold configured in the electroplating bath is configured to have an arc-shaped cross section or oval-shaped cross section, and a ratio (=a/b) between an electroplated line width (b) and a micro circuit pattern part line width (a) is 0.3 or less.