Shielding technique for semiconductor package including metal lid and metalized contact area
View Patent ↗In one embodiment a semiconductor package includes a metal lid configured as a shield that effectively surrounds the active circuitry, and thus forms a type of Faraday shield. The lid is electrically coupled to a metalized area located on the surface of the active circuitry, or to an additional metalized die. Appropriate interconnect methods between the lid and the metalized die or metalized area include, but are not restricted to, wire bonding, bumps, tabs, or similar techniques.
1. A semiconductor package comprising:
a semiconductor die having terminals and a metalized surface portion, the metalized surface portion disposed on a major surface of the semiconductor die and spaced apart from the terminals, the semiconductor die coupled to a die paddle, and the metalized surface portion electrically connected to the die paddle;
a wire mesh formed on the metalized surface portion of the semiconductor die;
a plurality of leads extending at least partially about the semiconductor die, wherein the semiconductor die and at least a portion of the plurality of leads are electrically connected;
a package body covering at least portions of the plurality of leads; and
a lid having a peripheral rim portion attached to the package body and a top portion, the top portion having a first surface facing the semiconductor die and a second surface opposite to the first surface and external to the semiconductor package, wherein the first surface is spaced apart from the package body, and wherein the wire mesh physically contacts the first surface to provide an electrically conductive path between the lid and the die paddle.
2. The semiconductor package of claim 1 wherein:
the package body includes a bottom surface, and a top surface having at least first and second sections, the first section being recessed relative to the second section;
the lid is attached to the second section of the top surface; and
the package body is formed such that at least some of the leads include a portion which is exposed in the first section of the top surface.
3. The semiconductor package of claim 2 wherein those leads which include a portion exposed in the first section of the top surface of the package body each comprise:
a generally planar top surface which is partially exposed in the first section of the top surface of the package body;
a generally planar bottom surface which is disposed in opposed relation to the top surface and exposed in the bottom surface of the package body; and
a shelf which is disposed in opposed relation to the top surface and recessed relative to the bottom surface, the shelf being covered by the package body.
4. The semiconductor package of claim 3 wherein the semiconductor die is electrically connected to the partially exposed top surfaces of at least some of the leads through the use of conductive wires which are covered by the lid.
5. The semiconductor package of claim 2 wherein the lid is attached to the second section of the top surface of the package body by a non-conductive epoxy.
6. The semiconductor package of claim 1 wherein the wire mesh is sized to be of a loop height which is selected to facilitate at least a partial compaction of the wire mesh between the semiconductor die and the lid.
7. A semiconductor package comprising:
a die pad;
a semiconductor die attached to the die pad having a plurality of terminals and a metalized surface portion, wherein the metalized surface portion is centrally located on the semiconductor die and spaced apart from the terminals;
a wire mesh formed on the metalized surface portion of the semiconductor die;
a plurality of leads extending at least partially about the die pad in spaced relation thereto, the semiconductor die being electrically connected to at least some of the leads and the metalized surface portion being electrically connected to the die pad;
a package body comprising an encapsulant material covering at least portions of the die pad and the leads; and
a lid having a peripheral rim portion attached to the package body and a top portion, the top portion having a first surface facing the semiconductor die and a second surface opposite to the first surface and external to the semiconductor package, wherein the first surface is spaced apart from the package body and physically contacts the wire mesh, and wherein the lid is electrically connected to the die pad through the wire mesh and the metalized surface portion.
8. The semiconductor package of claim 7 wherein:
the package body includes a bottom surface, and a top surface having at least first and second sections, the first section being recessed relative to the second section and disposed between inner ends of the plurality of leads and a side surfaces of the die pad;
the lid is attached to the second section of the top surface; and
the package body is formed such that the die pad and at least some of the leads each include a portion which is exposed in the first section of the top surface.
9. The semiconductor package of claim 8 wherein those leads which include a portion exposed in the first section of the top surface of the package body each comprise:
a generally planar top surface which is partially exposed in the first section of the top surface of the package body;
a generally planar bottom surface which is disposed in opposed relation to the top surface and exposed in the bottom surface of the package body; and
a shelf which is disposed in opposed relation to the top surface and recessed relative to the bottom surface, the shelf being covered by the package body.
10. The semiconductor package of claim 9 wherein the die pad comprises:
a generally planar top surface which is exposed in the first section of the top surface of the package body;
a generally planar bottom surface which is disposed in opposed relation to the top surface and exposed in the bottom surface of the package body; and
a shelf which is disposed in opposed relation to the top surface and recessed relative to the bottom surface, the shelf being covered by the package body.
11. The semiconductor package of claim 10 further comprising a plurality of tie bars which each extend from the die pad and comprise:
a generally planar top surface which is partially exposed in the first section of the top surface of the package body;
a generally planar bottom surface which is disposed in opposed relation to the top surface and is covered by the package body.
12. The semiconductor package of claim 10 wherein the semiconductor die is electrically connected to the top surface of the die pad and to the partially exposed top surfaces of at least some of the leads through the use of conductive wires which are covered by the lid.
13. The semiconductor package of claim 8 wherein the lid is attached to the second section of the top surface of the package body by a non-conductive epoxy.
14. The semiconductor package of claim 7 wherein the wire mesh is sized to be of a loop height which is selected to facilitate at least a partial compaction of the wire mesh between the semiconductor die and the lid.
15. A semiconductor package comprising:
a die pad;
a first semiconductor die attached to the die pad;
a second semiconductor die stacked upon and attached to the first semiconductor die, the second semiconductor die defining a metalized surface portion and being electrically connected to the die pad;
a wire mesh formed on the metalized surface portion of the second semiconductor die;
a plurality of leads extending at least partially about the die pad in spaced relation thereto, the first semiconductor die being electrically connected to at least some of the leads;
a package body covering at least portions of the die pad and the leads, wherein the wire mesh is devoid of the package body; and
a lid having a peripheral rim portion attached to the package body and a top portion, the top portion having a first surface facing the second semiconductor die and a second surface opposite to the first surface and external to the semiconductor package, wherein the first surface is spaced apart from the package body and physically contacts at least a portion of the wire mesh, and wherein the lid is electrically connected to the die pad through the wire mesh and the metalized surface portion.
16. The semiconductor package of claim 15 wherein:
the package body includes a bottom surface, and a top surface having at least first and second sections, the first section being recessed relative to the second section;
the lid is attached to the second section of the top surface; and
the package body is formed such that the die pad and at least some of the leads each include a portion which is exposed in the first section of the top surface.
17. The semiconductor package of claim 16 wherein:
those leads which include a portion exposed in the first section of the top surface of the package body each comprise a generally planar top surface which is partially exposed in the first section of the top surface of the package body, a generally planar bottom surface which is disposed in opposed relation to the top surface and exposed in the bottom surface of the package body; and
the die pad comprises a generally planar top surface which is exposed in the first section of the top surface of the package body, and a generally planar bottom surface which is disposed in opposed relation to the top surface and exposed in the bottom surface of the package body.
18. The semiconductor package of claim 17 wherein the first semiconductor die is electrically connected to the top surface of the die pad and to the partially exposed top surfaces of at least some of the leads, and the second semiconductor die is electrically connected to the top surface of the die pad, through the use of conductive wires which are covered by the lid.
19. The semiconductor package of claim 16 wherein the lid is attached to the second section of the top surface of the package body by a non-conductive epoxy.
20. The semiconductor package of claim 15 wherein the wire mesh is sized to be of a loop height which is selected to facilitate at least a partial compaction of the wire mesh between the second semiconductor die and the lid.