Abstract: There is provided a light source device, a headlight, a display apparatus, and an illumination apparatus having excellent heat dissipation. The light source device includes a substrate, a phosphor, a light emitting element, and a wavelength-selective reflecting member. The phosphor is disposed in contact with the substrate. The light emitting element emits excitation light for exciting the phosphor. The wavelength-selective reflecting member partially reflects the excitation light emitted from the light emitting element to be guided to the phosphor and transmits fluorescence emitted from the phosphor by excitation caused by incidence of the excitation light and the excitation light reflected by the phosphor.

Abstract: A semiconductor element mounting board includes: a circuit conductor disposed on the insulating board, a plurality of semiconductor element connection pads connected to the circuit conductor, a semiconductor element mounted on a surface of the insulating board, a first capacitor and a second capacitor disposed on a surface or an inside of the insulating board, and a first conductor path configured to connect the first capacitor between the semiconductor element connection pads, and a second conductor path configured to connect the second capacitor between the semiconductor element connection pads; and an inductance of the first conductor path is smaller than an inductance of the second conductor path, and capacitance of the first capacitor is smaller than capacitance of the second capacitor, and an internal inductance of the first capacitor is smaller than an internal inductance of the second capacitor.

Abstract: A semiconductor element mounting board includes: a circuit conductor disposed on the insulating board, a plurality of semiconductor element connection pads connected to the circuit conductor, a semiconductor element mounted on a surface of the insulating board, a first capacitor and a second capacitor disposed on a surface or an inside of the insulating board, and a first conductor path configured to connect the first capacitor between the semiconductor element connection pads, and a second conductor path configured to connect the second capacitor between the semiconductor element connection pads; and an inductance of the first conductor path is smaller than an inductance of the second conductor path, and capacitance of the first capacitor is smaller than capacitance of the second capacitor, and an internal inductance of the first capacitor is smaller than an internal inductance of the second capacitor.

Abstract: A wiring board includes an insulating substrate having a plurality of laminated insulating layers and a mounting part in one surface of the insulating substrate, a large number of semiconductor element connection pads, a large number of external connection pads, and a solid pattern extending from a region corresponding to the mounting part to the peripheral portion of the insulating substrate, and including a straight line shaped current path without intervention of gas vent openings.

Abstract: A wiring board including an insulating board formed such that an inner insulating layer is laminated under a front insulating layer, a pair of semiconductor element connection pads for a signal, formed on the front insulating layer, and a pair of strip-shaped wiring conductors formed on the inner insulating layer, having connection ends connected to the pair of pads for the signal under the pair of pads through via holes, and having parallel extending portions extending to an outer peripheral portion from the connection ends on the inner insulating layer in parallel to each other, where a part from the connection end to one part of the parallel extending portion has a width smaller than a width of a residual part, and length equal to or less than one-sixteenth of a wavelength of a signal transmitting in the pair of strip-shaped wiring conductors.

Abstract: A wiring board includes an insulating substrate having a plurality of laminated insulating layers and a mounting part in one surface of the insulating substrate, a large number of semiconductor element connection pads, a large number of external connection pads, and a solid pattern extending from a region corresponding to the mounting part to the peripheral portion of the insulating substrate, and including a straight line shaped current path without intervention of gas vent openings.

Abstract: The wiring board according to the embodiment of the present invention includes a core substrate including a through-hole for a grounding and a through-hole for a power supply disposed adjacent to each other, and a build-up layer formed on one surface of the core substrate. The through-hole for a grounding and the through-hole for a power supply have a cross-sectional shape perpendicular to a thickness direction of the core substrate, being any one of a triangular shape, a quadrangular shape and a hexagonal shape, containing a corner portion and a side portion connecting between the corner portions. The side portions of the through-hole for a grounding and the through-hole for a power supply being mutually adjacent are disposed so as to face each other.

Abstract: A wiring board including an insulating board formed such that an inner insulating layer is laminated under a front insulating layer, a pair of semiconductor element connection pads for a signal, formed on the front insulating layer, and a pair of strip-shaped wiring conductors formed on the inner insulating layer, having connection ends connected to the pair of pads for the signal under the pair of pads through via holes, and having parallel extending portions extending to an outer peripheral portion from the connection ends on the inner insulating layer in parallel to each other, where a part from the connection end to one part of the parallel extending portion has a width smaller than a width of a residual part, and length equal to or less than one-sixteenth of a wavelength of a signal transmitting in the pair of strip-shaped wiring conductors.