Stacked module

A stacked module, comprising:

• a first multilayer substrate that includes an opening having a stepwise wall face, and a first transmission line configured from a first line conductor provided on a front face side of a first substrate and a first grounding conductor layer provided on a back face side of the first substrate;
• a second multilayer substrate supported on a stepped portion provided on the stepwise wall face of the opening and including a second transmission line configured from a second line conductor provided on a front face side of a second substrate and a second grounding conductor layer provided on a back face side of the second substrate;
• a first semiconductor chip mounted on a bottom face of the opening of the first multilayer substrate and electrically coupled to a third transmission line provided on the first multilayer substrate;
• and
• a second semiconductor chip mounted on the front face of the second multilayer substrate and electrically coupled to the second transmission line;
• wherein
• a face to which the second grounding conductor layer or a fourth grounding conductor layer electrically coupled to the second grounding conductor layer is exposed is joined to the stepped portion provided on the first grounding conductor layer or on the opposite side of the first grounding conductor layer across the substrate on the lower side of the first grounding conductor layer and to which a third grounding conductor layer electrically coupled to the first grounding conductor layer is exposed, and the first grounding conductor layer and the second grounding conductor layer are electrically coupled to each other.