Power semiconductor package with strap
View Patent ↗A semiconductor package and a method for fabricating a semiconductor package are disclosed. In one embodiment, the semiconductor package includes an exposed portion of a conductive strap at a package horizontal first surface and exposed surfaces of multiple leads at a package horizontal second surface. A power semiconductor die is mounted on a die pad connected to at least one lead having an exposed surface. Heat generated by the die within the package may be dissipated through thermal paths including the exposed surfaces.
1. A semiconductor package, comprising:
a die having a bottom surface and a top surface;
a die pad having first and second surfaces, the bottom surface of the die being mounted to the first surface of the die pad;
a plurality of leads, each of the leads having first and second surfaces, at least some of the leads being integrally connected to the die pad;
a conductive strap electrically connected to and extending between the top surface of the die and the first surface of at least one of the leads which is not integrally connected to the die pad; and
an encapsulant material encapsulating the die, at least a portion of the die pad, at least a portion of the conductive strap, and at least a portion of each of the leads such that the second surface of each of the leads is generally co-planar with an exterior surface of the encapsulant material.
2. The semiconductor package of claim 1 wherein a portion of the conductive strap is exposed in the encapsulant material.
3. The semiconductor package of claim 1 wherein at least a portion of the second surface of the die pad is exposed in the encapsulant material.
4. The semiconductor package of claim 1 wherein the conductive strap includes a through hole which is filled with the encapsulant material.
5. The semiconductor package of claim 1 , wherein the conductive strap comprises:
a first end portion coupled to the top surface of the die;
a second end portion coupled to the first surface of at least one of the leads; and
a central portion extending between the first and second end portions, the central portion having a through hole formed therein which is filled with the encapsulant material.
6. The semiconductor package of claim 1 wherein each of the leads includes a recessed portion which is adjacent to the second surface thereof and is filled with the encapsulant material.
7. The semiconductor package of claim 1 wherein the die pad has a recessed portion which is adjacent to and extends about the periphery of the second surface thereof, the recessed portion of the die pad being filled with the encapsulant material.
8. The semiconductor package of claim 1 wherein:
the conductive strap includes a flange portion having the lip formed thereon;
a conductive layer is disposed between the flange portion and the top surface of the die and between the lip and the die; and
the conductive layer has a first thickness adjacent to the lip and a second thickness adjacent to the flange portion, the first thickness exceeding the second thickness.
9. The semiconductor package of claim 1 wherein:
each of the leads has a recessed portion formed in the first surface thereof; and
the conductive strap has a foot portion which is disposed in the recessed portion of at least one of the leads.
10. The semiconductor package of claim 1 wherein the conductive strap is secured to the first surface of at least one of the leads by a conductive layer.
11. A semiconductor package, comprising:
a die;
a die pad having first and second surfaces, the die being mounted to the first surface of the die pad;
a plurality of leads, each of the leads having first and second surfaces, at least some of the leads being integrally connected to the die pad;
a conductive strap electrically connected to and extending between the die and the first surface of at least one of the leads which is not electrically connected to the die pad; and
an encapsulant material encapsulating the die, at least a portion of the die pad, at least a portion of the conductive strap, and at least a portion of each of the leads such that a portion of the conductive strap is exposed in and substantially flush with an exterior surface of the encapsulant material, at least a portion of the second surface of the die pad is exposed in and substantially flush with the exterior surface of the encapsulant material, and the second surface of each of the leads is exposed in and substantially flush with the exterior surface of the encapsulant material.
12. The semiconductor package of claim 11 wherein the conductive strap comprises:
a first end portion coupled to the die;
a second end portion coupled to the first surface of at least one of the leads; and
a central portion extending between the first and second end portions, the central portion having a through hole formed therein which is filled with the encapsulant material.
13. The semiconductor package of claim 11 wherein each of the leads has a recessed portion which is adjacent to the second surface thereof and is filled with the encapsulant material.
14. The semiconductor package of claim 11 wherein the die pad has a recessed portion adjacent to and extending about the periphery of the second surface thereof, the recessed portion being filled with the encapsulant material.
15. The semiconductor package of claim 11 wherein:
the conductive strap includes a flange portion having a lip formed thereon;
a conductive layer is disposed between the flange portion of the conductive strap and the die and between the lip and the die; and
the conductive layer has a first thickness adjacent to the lip and a second thickness adjacent to the flange portion, the first thickness exceeding the second thickness.
16. A semiconductor package, comprising:
a die;
a die pad having first and second surfaces, the die being mounted to the first surface of the die pad;
a plurality of leads, each of the leads having first and second surfaces, at least some of the leads being integrally connected to the die pad;
a conductive strap electrically connected to and extending between the die and the first surface of at least one of the leads which is not integrally connected to the die pad; and
an encapsulant material encapsulating the die, at least a portion of the die pad, at least a portion of the conductive strap, and at least a portion of each of the leads such that the second surface of each of the leads is exposed in and substantially flush with an exterior surface of the encapsulant material;
each of the leads having a recessed portion adjacent to the second surface thereof which is filled with the encapsulant material, and the die pad having a recessed portion adjacent to and extending about the periphery of the second surface thereof, the recessed portion of the die pad being filled with the encapsulant material.
17. The semiconductor package of claim 16 wherein the conductive strap comprises a through hole which is filled with the encapsulant material.
18. The semiconductor package of claim 16 wherein at least a portion of the second surface of the die pad is exposed in and substantially flush with the exterior surface of the encapsulant material.