Abstract: A transformer for an OBC of an electric vehicle includes: a housing; a cover for opening and closing a storage space of the housing; a plate-type primary coil embedded in the storage space of the housing and supplied with power from a charger side; and a plurality of plate-shaped secondary coils embedded in the storage space of the housing to independently generate an induced current by magnetic field induction from the primary coil and output the induced current to a high voltage battery, and according to this, there is an advantage of reducing the size and improving the product productivity.

Abstract: A transformer includes: an upper primary substrate (110) which is formed by stacking a plurality of dielectric substrates, each substrate being provided with spiral conductive patterns; a lower secondary substrate (120) which is formed by stacking a plurality of dielectric substrates, each substrate being provided with spiral conductive patterns, in which the lower secondary substrate is positioned below the upper primary substrate (110) in such a way that the lower secondary substrate comes into contact with the upper primary substrate (110) or is spaced apart from the upper primary substrate (110); and a secondary coil element (200) of a planar shape to produce an induced current by a current applied to the upper primary substrate (110) and the lower primary substrate (120).