Insulated power semiconductor module with reduced partial discharge and manufacturing method

A method for assembling a power semiconductor module, comprising the steps of:

• disposing a first electrically conductive layer on at least one portion of a top surface of an electrically insulating substrate, so that at least one peripheral top region of said electrically insulating substrate remains uncovered by the first electrically conductive layer;
• disposing a precursor of a first electrically insulating material in a first corner region formed by said first electrically conductive layer and said peripheral region of said electrically insulating substrate;
• polymerizing the precursor of the first electrically insulating material to form the first electrically insulating material;
• bonding a semiconductor chip onto said first electrically conductive layer;
• bonding the electrically insulating substrate onto a bottom plate;
• covering said semiconductor chip, said electrically insulating substrate, said first electrically conductive layer, and said first electrically insulating material at least partially with a second electrically insulating material;
• wherein
• the precursor of the first electrically insulating material(S) is a low viscosity monomer or oligomer that forms a polyimide when polymerizing, wherein
• small amounts of said precursor are being applied to the junction of said first electrically conductive layer and said peripheral region of said electrically insulating substrate.