Magnetic material core-embedded resin multilayer board, manufacturing method therefor, electronic device, and antenna device

A magnetic material core-embedded resin multilayer board comprising:

• a plurality of resin sheets stacked on each other;
• a cavity provided within the resin multilayer board;
• a magnetic material core that is a sintered body and is disposed within the cavity;
• and
• a conductor pattern provided on one of the plurality of resin sheets that directly faces the magnetic material core or on one of the plurality of resin sheets that indirectly faces the magnetic material core via another one of the plurality of resin sheets;
• wherein
• the magnetic material core is fractured along a portion of the conductor pattern.

An antenna device comprising:

• a magnetic material core-embedded resin multilayer board including:
• a plurality of resin sheets stacked on each other;
• a cavity provided within the resin multilayer board;
• a magnetic material core that is a sintered body and is disposed within the cavity;
• and
• a conductor pattern provided on one of the plurality of resin sheets that directly faces the magnetic material core or on one of the plurality of resin sheets that indirectly faces the magnetic material core via another one of the plurality of resin sheets;
• wherein
• the magnetic material core is fractured along a portion of the conductor pattern;
• and
• a coil conductor defined by the conductor pattern in the magnetic material core-embedded resin multilayer board.

A manufacturing method for a magnetic material core-embedded resin multilayer board, comprising:

• a preliminary pressure-bonding step of preliminarily pressure-bonding a magnetic material core, which is a sintered body, to at least one resin sheet to form a magnetic material core-equipped resin sheet;
• and
• a full pressure-bonding step of stacking a plurality of resin sheets including a resin sheet including a conductor pattern formed thereon, a resin sheet including an aperture formed therein, and the magnetic material core-equipped resin sheet, in a state in which the magnetic material core is disposed in a cavity formed by the aperture, and fully pressure-bonding the plurality of resin sheets;
• wherein
• in the preliminary pressure-bonding step or the full pressure-bonding step, a crack is formed in the magnetic material core along a conductor pattern formed on a resin sheet that directly faces the magnetic material core or on a resin sheet that indirectly faces the magnetic material core via another resin sheet.