Component-embedded substrate and manufacturing method thereof

A method for manufacturing a component-embedded substrate in which a component is embedded, the component having a plurality of terminal electrodes, at least part of the terminal electrodes being provided on an opposite surface with respect to a predetermined direction, the method comprising:

• forming, in a plurality of resin layers which are made of a thermoplastic material, a plurality of joining conductors which are to be joined to the plurality of terminal electrodes, a plurality of wiring conductors which are to be electrically coupled to the plurality of joining conductors, and at least one auxiliary member within a region where the component is to be placed when viewed in plan in the predetermined direction;
• forming a multilayer body by stacking up the plurality of resin layers in the predetermined direction while embedding the component during the stacking of the layers;
• and
• heating and compressing the multilayer body,
• wherein the auxiliary member is electrically insulated from each of the plurality of wiring conductors and arranged to balance pressures acting on the plurality of terminal electrodes during the heating and compression of the multilayer body.