Patent ID: 8502632

Claim:
A transformer comprising: a winding member; and a core member being made of magnetic material, said core member including a middle leg portion and being disposed around said winding member such that said core member forms a magnetic path, wherein: said winding member comprises a first substrate and at least two second substrates which are stacked, each one of said first substrate and said second substrates is provided with an insertion hole and a patterned conductor which surrounds said insertion hole, said insertion hole is provided for passing the middle leg portion of said core member, said patterned conductor of said first substrate is defined by a one-turn patterned conductor which has one turn, whereby said patterned conductor of said first substrate defines a first winding, said patterned conductor of each of said second substrates defines a second winding, said transformer further comprises an interlayer connection member which is configured to electrically connect said patterned conductors of said second substrate, which is stacked, to each other, said interlayer connection member is located inward of said one-turn patterned conductor, said interlayer connection member is located in an end side of said one-turn patterned conductor, and said interlayer connection member is disposed such that a distance between an end portion of said interlayer connection member on a side of middle leg portion and an end portion of said middle leg portion on a side of the interlayer connection member is equal to or more than 0.5 mm.