Semiconductor device and power conversion device

A semiconductor device comprising:

• a positive electrode-side semiconductor element including a first positive electrode and a first negative electrode;
• a negative electrode-side semiconductor element including a second positive electrode and a second negative electrode;
• a positive electrode plate connected to the first positive electrode of the positive electrode-side semiconductor element;
• a negative electrode plate connected to the second negative electrode of the negative electrode-side semiconductor element;
• an AC electrode plate connected to the first negative electrode of the positive electrode-side semiconductor element and the second positive electrode of the negative electrode-side semiconductor element;
• a positive electrode-side auxiliary electrode terminal;
• a negative electrode-side auxiliary electrode terminal;
• a positive electrode-side capacitor connected to the positive electrode plate and the positive electrode-side auxiliary electrode terminal;
• and
• a negative electrode-side capacitor connected to the negative electrode plate and the negative electrode-side auxiliary electrode terminal;
• a heat dissipation conductor;
• and
• an insulator provided between the heat dissipation conductor and each of the positive electrode plate, the negative electrode plate and the AC electrode plate, wherein
• a capacitance of the positive electrode-side capacitor is greater than a capacitance provided between the first positive electrode of the positive electrode-side semiconductor element and the heat dissipation conductor with the positive electrode plate interposed therebetween, and
• a capacitance of the negative electrode-side capacitor is greater than a capacitance provided between the second negative electrode of the negative electrode-side semiconductor element and the heat dissipation conductor with the negative electrode plate interposed therebetween.