A printed circuit board includes: a substrate structure having a first surface including a chip mounting region on which a semiconductor chip is mounted and a second surface opposite to the first surface, the second surface having a rectangular shape having first to fourth edges and first to fourth corners formed by the first to fourth edges, and pad patterns on the second surface of the substrate structure, wherein the second surface includes a first region including a region corresponding to the chip mounting region and in contact with the first to fourth edges, respectively, and second regions adjacent to the first to fourth corners, respectively and spaced apart from each other by the first region, wherein the pad patterns include first pad patterns in the first region and surface-treated with a nickel/gold (Ni/Au) layer, and second pad patterns in the second regions and surface-treated with an organic solderability preservative.

A metal circuit structure based on a flexible printed circuit (FPC) contains: a substrate, a first metal layer attached on the substrate, a second metal layer formed on the first metal layer, and an intermediate layer defined between the first metal layer and the second metal layer. A first surface of the intermediate layer is connected with the first metal layer, and a second surface of the intermediate layer is connected with the second metal layer. The intermediate layer is made of a first material, the second metal layer is made of a second material, and the first material of the intermediate layer does not act with the second material of the second metal layer.

In an insulating circuit substrate, aluminum sheets formed of aluminum or an aluminum alloy are laminated and bonded to a surface of a ceramic substrate and, in the aluminum sheets, Cu is solid-solubilized at a bonding interface with the ceramic substrate and a ratio B/A between a Cu concentration A mass % at the bonding interface and a Cu concentration B mass % at a position of 100 μm in a thickness direction from the bonding interface to the aluminum sheets side is 0.30 or more and 0.85 or less.

An electric circuit board includes an insulating substrate, a metal plate, and a brazing material with which the insulating substrate and the metal plate are joined together. The metal plate has a side surface over which recessed portions are scattered. The side surface of the metal plate has lines in regions around the recessed portions. The metal plate is made of copper or a copper alloy. The brazing material has a side surface that is continuous with the side surface of the metal plate. The brazing material is a silver-copper brazing alloy. A ratio of copper on the side surface of the brazing material is higher than a copper component ratio of the silver-copper brazing alloy.

A resin flux solder paste includes a solder powder, and a flux, in which the flux contains at least an epoxy resin, a curing agent, a curing accelerator, and an activator, the epoxy resin contains 10% to 90% by weight of one or more of a biphenyl aralkyl type epoxy resin, a naphthalene type epoxy resin, and a dicyclopentadiene type epoxy resin, having an epoxy equivalent of 200 to 400, with respect to a total amount of the epoxy resin, and the curing agent contains 30% to 95% by weight of a biphenyl aralkyl phenol resin having a hydroxyl group equivalent of 150 to 350 with respect to a total amount of the curing agent, and 5% to 70% by weight of a phenol novolac resin having an allyl group having a hydroxyl group equivalent of 100 to 200 with respect to the total amount of the curing agent.

Disclosed is a method for manufacturing a wiring structure including a step of forming a wiring on an insulating resin layer. The step of forming the wiring includes: forming a modified region including pores in a surface layer of the insulating resin layer by treating a surface of the insulating resin layer with a treatment method including surface modification; forming a seed layer on the surface of the insulating resin layer by sputtering; and forming the wiring on the seed layer by electrolytic copper plating. The disclosed method may include, in this order: a step of forming a surface treatment agent layer that covers a surface of the wiring by treating the surface of the wiring with a surface treatment agent for improving adhesion; and a step of forming a modified region including pores in a surface layer of a first layer of the insulating resin layer by treating the surface of the first layer of the insulating resin layer with a treatment method including surface modification.

Examples are provided for a flexible circuit element including a flexible insulating support structure, a solid metal trace extending at least partially between a first connector and a second connector on the flexible insulating support structure, and a liquid metal conductor disposed in contact with the solid metal trace in a region of the trace configured to repeatedly flex when installed in a device.

A device including an electrically conducting track arranged on a support includes a step of supply of the support, and a step of formation of the electrically conducting track on the support including a step of supply of a solution intended to be deposited on the support, a step of deposition of the solution by printing on the support. The step of supply of the solution is such that the solution supplied includes a mixture of a solvent, of a set of metal particles and of a metallic material having a melting point below that of the metal particles of the set of metal particles, and the method includes a step of melting of the metallic material which results in the formation of a solder of metallic material between metal particles of the set of metal particles.

A method for manufacturing a structure for embedding and packaging multiple devices by layer includes preparing a polymer supporting frame, mounting a first device in a first device placement mouth frame to form a first packaging layer, forming a first circuit layer and a second circuit layer, forming a second conductive copper pillar layer and a second sacrificial copper pillar layer, forming a second insulating layer on the first circuit layer, and forming a third insulating layer on the second circuit layer, forming a second device placement mouth frame vertically overlapped with the first device placement mouth frame, mounting a second device and a third device in the second device placement mouth frame to form a second packaging layer, forming a third circuit layer on the second insulating layer. A terminal of the second device and a terminal of the third device are respectively communicated with the third circuit layer.

The present invention provides a carrier-attached copper foil, wherein an ultrathin copper foil is not peeled from the carrier prior to the lamination to an insulating substrate, but can be peeled from the carrier after the lamination to the insulating substrate. A carrier-attached copper foil comprising a copper foil carrier, an intermediate layer laminated on the copper foil carrier, and an ultrathin copper layer laminated on the intermediate layer, wherein the intermediate foil is configured with a Ni layer in contact with an interface of the copper foil carrier and a Cr layer in contact with an interface of the ultrathin copper layer, said Ni layer containing 1,000-40,000 μg/dm.sup.2 of Ni and said Cr layer containing 10-100 μg/dm.sup.2 of Cr is provided.