A resin composition contains a resin component (A) and a phosphorus-containing flame retardant (B). The resin component (A) contains an epoxy resin (a1), of which the viscosity at 25° C. is equal to or less than 50000 mPa.Math.s. The proportion of the epoxy resin (a1) to the resin component (A) is equal to or greater than 20% by mass. The phosphorus-containing flame retardant (B) includes a phosphorus-containing flame retardant (B1) that neither melts nor thermally decomposes at a temperature lower than 150° C.

A wiring board includes a substrate including a first surface and a second surface located on an opposite side to the first surface, where the substrate has stretchability, an interconnection wire located adjacent to the first surface of the substrate, and a stress relaxation layer located between the first surface of the substrate and the interconnection wire, where the stress relaxation layer has a modulus of elasticity lower than that of the substrate.

A circuit board includes, in order in a stacking direction, a first insulating layer, a second insulating layer in contact with the first insulating layer, and a conductor layer, the first insulating layer includes a liquid crystal polymer as a main component, and the second insulating layer includes a fluoropolymer including at least one of polytetrafluoroethylene and a perfluoroalkoxy alkane and includes a polyimide resin with an imidization rate of about 90% or more, the polyimide resin being present in an amount of about 0.5 parts or more by weight and less than about 20 parts by weight per 100 parts by weight of the fluoropolymer.

A circuit board structure for mobile PCI express module is applied to conform to PCI Express 4.0 specification. The circuit board structure includes a top signal layer and a bottom signal layer with a core and a conductive copper wire, a power supply layer disposed between the top signal layer and the bottom signal layer, a plurality of first insulating layers disposed between the top signal layer and the power supply layer and between the bottom signal layer and the power supply layer, and a plurality of second insulating layers disposed between the power supply layer and the first insulating layers. The dielectric loss values of the first insulating layer and the second insulating layer are between 0.004 and 0.014, and the length of the conductive cooper wire is between 500 and 2500 mil, so that the signal loss of the mobile PCI express module is less than 8 dB.

An electronic device with self-recovering properties including a substrate including a polymer composite, a conductive pattern disposed on the substrate, and an electrode disposed on the conductive pattern is provided, and the polymer composite includes a composite of different first and second polymers, the first polymer includes a first functional group capable of forming a hydrogen bond between polymer chains, and the second polymer includes a second functional group capable of forming a hydrogen bond between polymer chains.

A multilayered polyimide film includes a first polyimide layer containing fluorine-containing polymer particles and having a first surface and a second surface, and a second polyimide layer and a third polyimide layer respectively disposed on the first surface and the second surface. The second and the third polyimide layers contain organic silicon oxygen compound particles. The multilayered polyimide film has a coefficient of thermal expansion (CTE) between about 13 and about 30 ppm/° C.

A circuit board includes a substrate, a first magnetic structure, a first dielectric layer and an inductive coil. The substrate has a top surface and a bottom surface. The first magnetic structure is disposed on the top surface of the substrate. The first dielectric layer covers the substrate and the first magnetic structure. The inductive coil includes a first interconnect, a second interconnect and a plurality of conductive pillars. The first interconnect is disposed on the first dielectric layer. The second interconnect is disposed on the bottom surface of the substrate. The conductive pillars connect the first interconnect and the second interconnect. The first interconnect, the second interconnect and the conductive pillars form a helical structure surrounding the first magnetic structure.

A resin substrate includes an insulating substrate, and first and second signal conductors that partially extend in parallel or substantially in parallel with each other along a signal transmission direction. The first signal conductor includes a parallel portion that extends in parallel or substantially in parallel with the second signal conductor along the signal transmission direction, and a first connection portion. In a portion where the first signal conductor and the second signal conductor extend in parallel or substantially in parallel with each other, the first signal conductor and the second signal conductor are disposed at a same position in the thickness direction of the insulating substrate, and the first connection portion is disposed at a different position from the second signal conductor in the thickness direction and a width direction of the insulating substrate.

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.

Buffer structures are provided that can be used to reduce a strain in a conformable electronic system that includes compliant components in electrical communication with more rigid device components. The buffer structures are disposed on, or at least partially embedded in, the conformable electronic system such that the buffer structures overlap with at least a portion of a junction region between a compliant component and a more rigid device component. The buffer structure can have a higher value of Young's modulus than an encapsulant of the conformable electronic system.