Wiring board, multilayer wiring board, method for manufacturing a multilayer wiring board, coil structure, and magnetic device

Abstract

To provide a wiring board that offers excellent embedding properties and can be stacked flat. [Solution] A wiring board 100 comprising an insulating substrate 11, a copper foil etched in a pattern and provided on at least one surface of the insulating substrate 11, and an insulating layer 2 provided on the copper foil and formed by heat-pressing an adhesive sheet, wherein the copper foil consists of a circuit pattern 12 and a dummy pattern 13, the area ratio of the copper foil (circuit pattern 12 and dummy pattern 13) is 25% or more and 95% or less of the substrate area, and the minimum melt viscosity of the adhesive sheet before heat-pressing, measured by a rheometer at temperatures from 40°C to 170°C, is 1,000 Pa·s or more and 100,000 Pa·s or less.

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