Isolator

An isolator comprising:

• a first coil at a primary side;
• a second coil at a secondary side, the second coil being magnetically coupled to the first coil;
• a first insulating film provided between the first coil and the second coil, the second coil being provided at a front surface side of the first insulating film, the first coil being provided at a back surface side of the first insulating film;
• and
• a primary side conductor provided at the front surface side of the first insulating film, the primary side conductor being apart from the second coil and electrically connected to the primary side,
• the first insulating film including a plurality of island-shaped convex portions being provided at the front surface side, the plurality of island-shaped convex portions being provided between the second coil and the primary side conductor,
• the plurality of island-shaped convex portions providing a creepage distance from the second coil to the primary side conductor along the front surface of the first insulating film, the creepage distance being longer in any direction along the front surface of the first insulating film than a direct distance from the second coil to the primary side conductor.