A semiconductor device, comprising: a semiconductor die wherein the semiconductor die comprises a first major surface having a first contact terminal arranged thereon and an opposing second major having a second contact terminal arranged thereon; a first lead frame having first and second opposing major surfaces wherein the first major surface is fixedly attached to the first contact terminal of the semiconductor die; a second lead frame having first and second opposing major surfaces wherein the first major surface is fixedly attached to the second contact terminal of the semiconductor die; a mould material configured and arranged to encapsulate the semiconductor die, wherein the first lead frame comprises an integrally formed external contact portion extending from the first major surface thereof to a plane co-planar with the second major surface of the second lead frame, wherein the first and second lead frames (108, 110) are respective first and second heat sinks configured and arranged such that respective second major surfaces are exposed through the mould material at respective first and second major surfaces of the semiconductor device; wherein the second major surface of the first lead frame is co-planar with the mould material at the first major surfaces of the semiconductor device; wherein the second major surface of the second lead frame is co-planar with the mould material at the second major surface of the semiconductor device; wherein the integrally formed external contact portion of the first lead frame extends along a length of a side wall from the first to the second major surfaces of the semiconductor device, wherein the first and second lead frames (108, 110) are L - shaped in cross-section, characterized in that the second lead frame comprises an integrally formed external contact portion which extends partially along a length of a side wall from the second major surface towards the first major surface of the semiconductor device; wherein the length of the external contact portion of the first lead frame is greater than the length of the external contact portion of the second lead frame. a semiconductor die wherein the semiconductor die comprises a first major surface having a first contact terminal arranged thereon and an opposing second major having a second contact terminal arranged thereon; a first lead frame having first and second opposing major surfaces wherein the first major surface is fixedly attached to the first contact terminal of the semiconductor die; a second lead frame having first and second opposing major surfaces wherein the first major surface is fixedly attached to the second contact terminal of the semiconductor die; a mould material configured and arranged to encapsulate the semiconductor die, wherein the first lead frame comprises an integrally formed external contact portion extending from the first major surface thereof to a plane co-planar with the second major surface of the second lead frame, wherein the first and second lead frames (108, 110) are respective first and second heat sinks configured and arranged such that respective second major surfaces are exposed through the mould material at respective first and second major surfaces of the semiconductor device; wherein the second major surface of the first lead frame is co-planar with the mould material at the first major surfaces of the semiconductor device; wherein the second major surface of the second lead frame is co-planar with the mould material at the second major surface of the semiconductor device; wherein the integrally formed external contact portion of the first lead frame extends along a length of a side wall from the first to the second major surfaces of the semiconductor device, wherein the first and second lead frames (108, 110) are L - shaped in cross-section, characterized in that the second lead frame comprises an integrally formed external contact portion which extends partially along a length of a side wall from the second major surface towards the first major surface of the semiconductor device; wherein the length of the external contact portion of the first lead frame is greater than the length of the external contact portion of the second lead frame.