Molded semiconductor module having a mold step for increasing creepage distance

A semiconductor module includes: a dual-gauge leadframe having thicker and thinner parts, part of the thinner part forming a high voltage lead; a semiconductor die attached to the thicker part; and a molding compound (MC) encapsulating the die. The thicker leadframe part is disposed at a bottom side of the MC. A side face of the MC has a stepped region between the high voltage lead and thicker leadframe part. A first generally vertical part of the stepped region extends from the high voltage lead to the generally horizontal part, a generally horizontal part of the stepped region extends to the second generally vertical part, and a second generally vertical part of the stepped region extends to the bottom side of the MC. A linear dimension of the generally horizontal part as measured from the first generally vertical part to the second generally vertical part is at least 4.5 mm.