Power semiconductor device

A power semiconductor device comprising:

• a disc-shaped first electrode having a first contact face;
• a disc-shaped second electrode having a second contact face opposite to the first contact face;
• a wafer sandwiched between the first electrode and the second electrode;
• an outer insulating ring attached to the first electrode and to the second electrode, the outer insulating ring surrounding the wafer;
• an inner insulating ring inside of the outer insulating ring and surrounding the wafer;
• a ring-shaped first flange portion laterally surrounding a main portion of the first electrode;
• and
• an O-ring radially surrounding the main portion of the first electrode and being sandwiched in a vertical direction perpendicular to the first contact face between the inner insulating ring and the first flange portion;
• wherein the first electrode has a second flange portion radially extending from the main portion of the first electrode on a side of the first flange portion opposite to the O-ring;
• and
• wherein the O-ring is resiliently reversibly deformable and wherein in a relaxed state the O-ring has a cross-section that is elongated in the vertical direction such that, in the relaxed state, a height of the O-ring in the vertical direction is greater than a width of the O-ring in a radial direction that is parallel to the first contact face.

A power semiconductor device comprising:

• a first copper electrode having a first contact face and being disc-shaped;
• a second copper electrode having a second contact face and being disc-shaped, the second contact face being opposite to the first contact face;
• a wafer sandwiched between the first electrode and the second electrode;
• a ceramic outer insulating ring attached to the first electrode and to the second electrode, the outer insulating ring surrounding the wafer;
• a polymer inner insulating ring inside of the outer insulating ring and surrounding the wafer, the inner insulating ring comprising polymer material;
• a ring-shaped first flange portion laterally surrounding a main portion of the first electrode;
• and
• an O-ring radially surrounding the main portion of the first electrode and being sandwiched in a vertical direction perpendicular to the first contact face between the inner insulating ring and the first flange portion, wherein the O-ring is resiliently reversibly deformable and wherein in a relaxed state the O-ring has a cross-section that is elongated in the vertical direction such that, in the relaxed state, a height of the O-ring in the vertical direction is greater than a width of the O-ring in a radial direction that is parallel to the first contact face.