US 5,672,910 A · Semiconductor device and semiconductor module

Abstract

It is an object to downsize a device while maintaining a high breakdown voltage. An external terminal (7) protrudes to the outside from the side wall of a sealing resin (2) and a heat sink (1) is exposed in the bottom of the sealing resin (2). A step surface (21) retracted from the exposed surface of the heat sink (1) is formed in the part of the sealing resin (2) surrounding the periphery of the heat sink (1). When using this semiconductor device, the exposed surface of the heat sink (1) is brought into surface contact with the flat surface (41a) of the radiation fin (41) and an insulation sheet (31) is interposed between the step surface (21) and the flat surface (41a), and which is pressed therebetween. The insulation sheet (31) is disposed to cover the region facing the external terminal (7) in the flat surface (41a). Accordingly, it is possible to set the height of the external terminal (7) from the exposed surface of the heat sink (1) lower than the spatial distance determined on the basis of the rated voltage while keeping the breakdown voltage between the external terminal (7) and the radiation fin (41) as the rated voltage.

Claims18

Dependent claims

A semiconductor device, comprising:

a lead frame having a planar portion being electrically conductive and having first and second main surfaces and having therearound a plurality of external terminals outwardly projecting;
a power semiconductor element fixed on said first main surface;
a heat sink like a plate being thermally conductive and having third and fourth main surfaces and provided so that said third main surface faces said second main surface with a gap therebetween;
and
a sealing resin having electrically insulating properties and sealing said power semiconductor element, said lead frame, and said heat sink arranged so that said plurality of external terminals and said fourth main surface are exposed to an outside,
said plurality of external terminals includes a high breakdown voltage terminal that sets a breakdown voltage for the device, where the breakdown voltage corresponds to a rated voltage for said device developed between said high voltage terminal and said heat sink;
a portion interposed between said high breakdown voltage terminal and said fourth main surface in an outer surface of said sealing resin has a surface shape capable of pressing and holding a sheet having elasticity with an external flat surface in surface contact with said fourth main surface, and
a height of said plurality of external terminals measured from said fourth main surface is smaller than a permissible shortest spatial distance, which is a reference value corresponding to said rated voltage for said device.

5 more elements

A semiconductor device, comprising:

a lead frame having a planar portion being electrically conductive and having first and second main surfaces and having therearound a plurality of external terminals outwardly projecting;
a power semiconductor element fixed on said first main surface;
a heat sink like a plate being thermally conductive and having third and fourth main surfaces and provided so that said third main surface faces said second main surface with a gap therebetween;
and
a sealing resin having electrically insulating properties and sealing said power semiconductor element, said lead frame, and said heat sink arranged so that said plurality of external terminals and said fourth main surface are exposed to an outside;
said plurality of external terminals includes a high breakdown voltage terminal that sets a breakdown voltage for the device, where the breakdown voltage corresponds to a rated voltage for said device developed between said high voltage terminal and said heat sink,
wherein a creeping distance along a creepage path between said high breakdown voltage terminal and said heat sink along an outer surface of said sealing resin is equal to or larger than a permissible shortest creeping distance corresponding to said rated voltage, and
a height of said external terminals measured from said fourth main surface is smaller than a permissible shortest spatial distance, which is a reference value corresponding to said rated voltage for said device.

5 more elements