Microwave device having a conductive heat spreader and antenna having microwave device

A microwave device comprising:

• a first multilayer resin substrate including a plurality of ground via holes;
• a semiconductor substrate at one surface of the first multilayer resin substrate and including a high frequency circuit electrically connected to the first multilayer resin substrate;
• a conductive heat spreader at an opposite face of the semiconductor substrate from a face of the semiconductor substrate that faces the first multilayer resin substrate, the conductive heat spreader being electrically connected to the semiconductor substrate;
• a resin over the one surface of the first multilayer resin substrate and covering the semiconductor substrate and the conductive heat spreader;
• and
• a conductive film covering the resin and the conductive heat spreader and in contact with a face of the conductive heat spreader that faces away from the semiconductor substrate, wherein
• the semiconductor substrate includes a plurality of ground through holes extending through the semiconductor substrate in a stacking direction in which the first multilayer resin substrate, the semiconductor substrate, and the conductive heat spreader are stacked, the ground through holes being arranged within a surface of the semiconductor substrate,
• the first multilayer resin substrate includes a first ground pattern in an outer peripheral portion of another surface of the first multilayer resin substrate and a second ground pattern in an inner area within the another surface, the another surface being opposite the one surface,
• the plurality of ground via holes include:
• a plurality of first ground via holes at a position corresponding to the outer peripheral portion of the another surface in the first multilayer resin substrate and electrically connected to the conductive film and the first ground pattern provided in the outer peripheral portion, and
• a plurality of second ground via holes arranged in a distributed manner in the inner area within the another surface in the first multilayer resin substrate and electrically connected to the ground through holes and the second ground pattern in the inner area within the another surface,
• the conductive film is electrically connected to the first ground pattern provided in the outer peripheral portion via the first ground via holes and is electrically connected to the second ground pattern provided in the inner area within the another surface via the conductive heat spreader, the ground through holes of the semiconductor substrate, and the second ground via holes,
• the resin is directly in contact with an outer side surface of the conductive heat spreader in a same vertical plane as an outer side surface of the semiconductor substrate,
• a microwave signal line via hole is coaxially surrounded by the plurality of second ground via holes,
• the second through holes within the semiconductor substrate contacting the conductive heat spreader and the second ground via holes within the first multilayer resin substrate are arranged to implement electromagnetic shielding walls in a region surrounded by the conductive film and the first ground via holes,
• in a side sectional view, a signal line via hole is between a pair of the plurality of second ground via holes, and
• a chip bypass capacitor is mounted on the first multilayer resin substrate and is within the resin covered by the conductive film.