the inside of the first semiconductor element as seen in the stacking direction is made more than the connecting rigidity between the second semiconductor element and the substrate through the second synthetic resin at the outside of the second semiconductor element as seen in the stacking direction without the synthetic resin whose Young""s modulus is not less than Young""s modulus of the first synthetic resin at the inside of the second semiconductor element as seen in the stacking direction so that the connecting rigidity between the second semiconductor element and the substrate is substantially formed by a bending low rigidity of the second synthetic resin, the stress on the semiconductor element increases in accordance with the increase of the connecting rigidity between the semiconductor element and the substrate,increases in accordance with an increase of the rigidity against bending of the semiconductor element, and the stress on the semiconductor element decreases in accordance with the decrease in thickness thereof on the substrate, the crack or excessive stress on the second semiconductor element whose rigidity against bending is made more than the rigidity against bending of the first semiconductor element by a difference in Young""s modulus between the first and second semiconductor elements is effectively prevented.
When each of the first and second semiconductor elements includes a first surface facing to the substrate and a second surface as a reverse surface with respect to the first surface in the stacking direction, and the second surface of the first semiconductor element is prevented from being a grinder-finished surface while