Multilayer coil and method for manufacturing the same

A multilayer coil comprising:

• a first substrate including a first insulating base material layer and a first conductor pattern provided on the first insulating base material layer;
• a second substrate including a second insulating base material layer and a second conductor pattern provided on the second insulating base material layer;
• a joining layer that joins the first insulating base material layer and the second insulating base material layer together in a laminated state;
• a hole extending through the first insulating base material layer and the second insulating base material layer;
• and
• a conductor provided in the hole, and electrically connecting a portion of the first conductor pattern and a portion of the second conductor pattern to each other;
• wherein
• the joining layer is made of a thermoplastic resin;
• amounts of deformation of materials of the first insulating base material layer and the second insulating base material layer at a fusion temperature of the joining layer are less than an amount of deformation of the joining layer at the fusion temperature of the joining layer;
• the first conductor pattern and the second conductor pattern each include a coil pattern with a coil axis that extends in a lamination direction in which the first substrate and the second substrate are laminated together;
• the joining layer is a single layer;
• the multilayer coil includes a portion in which only the joining layer is interposed between the first conductor pattern and the second conductor pattern;
• and
• the conductor electrically connects only the portion of the first conductor pattern and the portion of the second conductor pattern to each other.