Provided herein is a carrier-attached copper foil having desirable laser drillability through an ultrathin copper layer, preferred for fabrication of a high-density integrated circuit substrate. The carrier-attached copper foil includes an interlayer and an ultrathin copper layer that are provided in this order on one or both surfaces of a carrier. The surface roughness Sz and the surface roughness Sa on the interlayer side of the ultrathin copper layer satisfy Sz3.6 m, and Sz/Sa14.00 as measured with a laser microscope in case of detaching the carrier from the carrier-attached copper foil according to JIS C 6471 after the carrier-attached copper foil is laminated to an insulating substrate from the ultrathin copper layer side under a pressure of 20 kgf/cm.sup.2 and heated at 220 C. for 2 hours. GMD, which is a 60-degree glossiness of the ultrathin copper layer surface on the interlayer side in MD direction, satisfies GMD150 in case of detaching the carrier from the carrier-attached copper foil according to JIS C 6471 after the carrier-attached copper foil is laminated using the same procedure.

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.

Some forms relate to an example stretchable electronic assembly. The stretchable electronic assembly includes a stretchable body that includes electronic components. A plurality of meandering conductors electrically connect the electronic components. The plurality of meandering conductors may be exposed from the stretchable body. A plurality of conductive pads are electrically connected to at least one of the electronic components or some of the plurality of meandering conductors. The plurality of conductive pads may be exposed from the stretchable body. The stretchable body includes an upper surface and lower surface. The plurality of meandering conductors may be exposed from the lower surface (in addition to, or alternatively to, the upper surface) of the stretchable body.

A wiring board includes: a wiring structure including: a first insulating layer; a first wiring layer formed on a bottom surface of the first insulating layer; and a protective insulating layer which covers the bottom surface of the first insulating layer and has a first opening; and a support base member bonded to the protective insulating layer with an adhesive layer and has a second opening. A diameter of the second opening at a position between the top surface and the bottom surface of the support base member in a thickness direction of the support base member is smaller than a diameter of the second opening at the top surface of the support base member and a diameter of the second opening at the bottom surface of the support base member, and smaller than a diameter of the first opening.

A substrate for mounting a semiconductor device includes an insulating layer having first and second opposed surfaces defining a thickness. First and second electrically conductive lands are included in the insulating layer. The first electrically conductive lands extend through the whole thickness of the insulating layer and are exposed on both the first and second opposed surfaces. The second electrically conductive lands have a thickness less than the thickness of the insulating layer and are exposed only at the first surface. Electrically conductive lines at the first surface of the insulating layer couple certain ones of the first electrically conductive lands with certain ones of the second electrically conductive lands. The semiconductor device is mounted to the first surface of the insulating layer. Wire bonding may be used to electrically coupling the semiconductor device to certain ones of the first and second lands.

Disclosed are an ultra-thin copper foil with a carrier foil and a method for manufacturing an embedded substrate by using the same, the ultra-thin copper foil with a carrier foil including: a carrier foil; a non-etching release layer on the carrier foil; a first ultra-thin copper foil layer on the non-etching release layer; an etch stop layer on the first ultra-thin copper foil layer; and a second ultra-thin copper foil layer on the etch stop layer.

Provided is a method for manufacturing a wiring board that forms a wiring layer having favorable adhesion without a resin resist pattern. A method prepares a substrate with seed-layer including: a underlayer on the surface of an insulating substrate; and a seed layer on the surface of the underlayer, the seed layer having a predetermined pattern and containing metal; presses a solid electrolyte membrane against the seed layer and the underlayer, and applies voltage between an anode and the underlayer to reduce metal ions in the membrane and form a metal layer on the surface of the seed layer; and removes an exposed region without the seed layer and the metal layer of the underlayer to form a wiring layer including the underlayer, the seed layer and the metal layer on the surface of the substrate.

Provided herein is a carrier-attached copper foil having desirable fine circuit formability. The carrier-attached copper foil includes a carrier, an interlayer, and an ultrathin copper layer in this order. The maximum trough depth Sv as measured with a laser microscope according to ISO 25178 on a surface of a bismaleimide-triazine resin substrate exposed by detaching the carrier and etching and removing the ultrathin copper layer after the carrier-attached copper foil is heat pressed against the resin substrate from the ultrathin copper layer side under the pressure of 20 kgf/cm.sup.2 at 220 C. for 2 hours is 0.181 to 2.922 m.

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, wherein a surface-treated layer is formed on a copper foil, and the proportion of the area corresponding to the particles of the surface of the surface-treated layer is 0.1 to 0.85.

A package substrate is provided. The package substrate includes a dielectric layer and a passive component embedded in the dielectric layer and contacting the dielectric layer. A circuit layer is embedded in the dielectric layer and has a first surface aligned with a second surface of the dielectric layer. A conductive structure is embedded in the dielectric layer and electrically connected to the passive component and the circuit layer. A chip package is also provided.