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 circuit board structure includes a dielectric substrate, at least one embedded block, at least one electronic component, at least one first build-up circuit layer, and at least one second build-up circuit layer. The dielectric substrate includes a through cavity penetrating the dielectric substrate. The embedded block is fixed in the through cavity. The embedded block includes a first through hole and a second through hole. The electronic component is disposed in the through hole of the embedded block. The first build-up circuit layer is disposed on the top surface of the dielectric substrate and covers the embedded block. The second build-up circuit layer is disposed on the bottom surface of the dielectric substrate and covers the embedded block.

Provided are a conductive composition for thin film printing and a method for forming a thin film conductive pattern, which can easily performing thin film printing, and can capable of improve conductivity by thermal sintering at a comparatively low temperature of 300° C. or less or by photo irradiation. A conductive composition comprises metal particles, a binder resin, and a solvent, the content of an organic compound in the solvent being 5 to 98% by mass, the organic compound comprising a hydrocarbon group having a bridged cyclic structure and a hydroxyl group, the content of metal particles being 15 to 60% by mass, the metal particles containing 20% by mass or more of flat metal particles, the content of the binder resin being 0.5 to 10 parts by mass relative to 100 parts by mass of the metal particles, and the viscosity at 25° C. being 1.0×10.sup.3 to 2×10.sup.5 mPa.Math.s. The composition is printed in a pattern having any selected shape on a substrate, by screen printing, and the pattern is subjected to thermal sintering at a temperature of 300° C. or less and/or subjecting the pattern to pulsed light irradiation.

Provided is a self-adhesive sheet including a 4-methyl-1-pentene-based polymer. In the self-adhesive sheet, it is preferable that at least one or more temperatures showing a local maximum value of a loss tangent (tan δ) , which is obtained by dynamic viscoelasticity measurement under conditions of a temperature rising rate of 4° C./min, a frequency of 1.59 Hz, and a strain amount of 0.1%, are present in a range of 10° C. or higher and 100° C. or lower, the local maximum value of the loss tangent is 0.5 or more and 3.5 or less, an arithmetic average roughness Ra on one surface of the self-adhesive sheet is in a range of 0.01 to 10 .Math.m, and a ten-point average roughness Rz is in a range of 0.1 to 50 .Math.m.

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 printed substrate includes a land that is to be soldered. The land includes a plating film that defines a surface of the land. The plating film includes a metal as a main constituent and a pi-acceptor molecule that is dispersed in the plating film. The pi-acceptor molecule has pi-acceptability and causes ligand field splitting equal to or greater than that of 2,2′-bipyridyl in spectrochemical series. A content of the pi-acceptor molecule in the plating film is equal to or greater than 0.1 weight percent, in terms of carbon atoms, with respect to the metal of the plating film.

The present invention relates to a method for fabricating blackened conductive patterns, which includes (i) forming a resist layer on a non-conductive substrate; (ii) forming fine pattern grooves in the resist layer using a laser beam; (iii) forming a mixture layer containing a conductive material and a blackening material in the fine pattern grooves; and (iv) removing the resist layer remained on the non-conductive substrate.

A power supply device includes a main unit and a power switching module. The main unit includes a primary circuit board, a transformer including a primary and a secondary coil, a primary-side circuit and a secondary-side circuit. The power switching module includes a separate PCB formed with at least two connection pads and two conductive tracks, and at least one power switching element disposed on the PCB and having two terminals respectively connected to the two connection pads through the two conductive tracks. The power switching module is in the form of a separate PCB that is electrically connected to the primary- or secondary-side circuits through the two connection pads.

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 conductive layer formed on at least one of surfaces of the base film. In the substrate for a printed circuit board, at least the conductive layer contains titanium in a dispersed manner. The conductive layer preferably contains copper or a copper alloy as a main component. A mass ratio of titanium in the conductive layer is preferably 10 ppm or more and 1,000 ppm or less. The conductive layer is preferably formed by application and heating of a conductive ink containing metal particles. The conductive ink preferably contains titanium or a titanium ion. The metal particles are preferably obtained by a titanium redox process including reducing metal ions using trivalent titanium ions as a reducing agent in an aqueous solution by an action of the reducing agent.

An object is to provide a substrate for a printed wiring board that has good circuit formability while maintaining adhesion strength between a conductive layer (2) and a base film (1). The substrate includes a base film having an insulating property (1) and a conductive layer (2) formed on at least one surface of the base film (1). The maximum height Sz, which is defined in ISO25178, of the surface of the base film (1) is 0.05 μm or more and less than 0.9 μm.