Power conversion unit
A heat sink includes a base having a flat plate shape and a heat dissipation fin. A housing accommodates the heat dissipation fin and is connected to ground. The base includes a first surface on which a semiconductor module is mounted, and a second surface opposite the first surface and to which the heat dissipation fin is fixed. The housing includes a flange supporting the second surface of the base. The power conversion unit further includes a first insulating member that electrically insulates the heat sink and the housing from each other. The first insulating member includes a base portion and a first bent portion. The base portion has a flat plate shape and is provided between the second surface of the base and the flange. The first bent portion is bent perpendicular to the base portion and is in surface contact with a side surface of the base.
1. A power conversion unit comprising:
a semiconductor module including a semiconductor element;
a heat sink including
a base having a flat plate shape, and
a heat dissipation fin;
a housing connected to ground, the housing accommodating the heat dissipation fin; and
the base including a first surface on which the semiconductor module is mounted, and a second surface which is opposite to the first surface and to which the heat dissipation fin is fixed,
the housing including a flange supporting the second surface of the base,
a first insulating member that electrically insulates the heat sink and the housing from each other, the first insulating member including
a base portion having a flat plate shape and provided between the second surface of the base and the flange, and
a first bent portion which is bent perpendicular to the base portion and is in surface contact with a side surface of the base,
wherein the first bent portion is in contact with a second insulating member to enclose an edge region of the base.
2. The power conversion unit according to claim 1 , wherein the first insulating member further includes a second bent portion which is bent perpendicular to the base portion and is in surface contact with a sidewall of the housing.
3. The power conversion unit according to claim 2 , wherein
the base has a first through hole passing through the base in a thickness direction,
each of the flange and the first insulating member has a second through hole overlapping the first through hole,
the power conversion unit further comprises:
a bolt passing through the first through hole and the second through holes of the first insulating member and the flange for fastening the base to the flange; and
the second insulating member and an insulating spacer that electrically insulates the heat sink and the bolt from each other,
the second insulating member has a flat plate shape and is provided between a head of the bolt and the first surface of the base, and
the insulating spacer is arranged inside the first through hole of the base so as to allow the bolt to pass therethrough.
4. The power conversion unit according to claim 3 , wherein the second insulating member has a thickness of not less than 0.5 mm and not greater than 2.0 mm.
5. The power conversion unit according to claim 2 , wherein the base portion of the first insulating member has a thickness of not less than 0.5 mm and not greater than 2.0 mm.
6. The power conversion unit according to claim 1 , wherein
the base has a first through hole passing through the base in a thickness direction,
each of the flange and the first insulating member has a second through hole overlapping the first through hole,
the power conversion unit further comprises:
a bolt passing through the first through hole and the second through holes of the first insulating member and the flange for fastening the base to the flange; and
the second insulating member and an insulating spacer that electrically insulates the heat sink and the bolt from each other,
the second insulating member has a flat plate shape and is provided between a head of the bolt and the first surface of the base, and
the insulating spacer is arranged inside the first through hole of the base so as to allow the bolt to pass therethrough.
7. The power conversion unit according to claim 6 , wherein the second insulating member has a thickness of not less than 0.5 mm and not greater than 2.0 mm.
8. The power conversion unit according to claim 1 , wherein the base portion of the first insulating member has a thickness of not less than 0.5 mm and not greater than 2.0 mm.