Abstract: It is possible to provide a transformer core which can be mounted on a coil having both ends connected to a substrate or the like and can simplify the step for arranging an adhesive layer and suppress fluctuation of a magnetic gap. The transformer core (1) includes: a rectangular spacer (5, 20) having a region where a first convex portion (10, 21) is formed on the four sides of one of the surfaces as a unitary block and the first convex portion is not provided at least at a part of a pair of two opposing sides; and a sheet-shaped adhesive layer (6) bonded to a region where at least the first convex portion is not provided on the one of the surfaces of the spacer and connecting a soft ferrite core (4) to the spacer.

Abstract: It is possible to provide a transformer core which can be mounted on a coil having both ends connected to a substrate or the like and can simplify the step for arranging an adhesive layer and suppress fluctuation of a magnetic gap. The transformer core (1) includes: a rectangular spacer (5, 20) having a region where a first convex portion (10, 21) is formed on the four sides of one of the surfaces as a unitary block and the first convex portion is not provided at least at a part of a pair of two opposing sides; and a sheet-shaped adhesive layer (6) bonded to a region where at least the first convex portion is not provided on the one of the surfaces of the spacer and connecting a soft ferrite core (4) to the spacer.