Fan-out wafer level packages having preformed embedded ground plane connections and methods for the fabrication thereof
Fan-Out Wafer Level Packages (FO-WLPs) and methods for fabricating FO-WLPs having Embedded Ground Plane (EGP) connections are provided. In one embodiment, the method includes forming a molded panel around an EGP array from which a plurality of preformed EGP connections project. One or more Redistribution Layers (RDLs) are produced over the molded panel. The molded panel is then singulated to yield a plurality of FO-WLPs each including a molded package body containing an EGP from the EGP array and one or more of preformed EGP connections.
1. A method for fabricating Fan-Out Wafer Level Packages (FO-WLPs), comprising:
bonding a plurality of preformed connections to a ground plane array, the ground plane array comprising a plurality of ground plane structures interconnected by a plurality of spars;
after bonding the plurality of preformed connections to the ground plane array, placing the plurality of preformed connections and the ground plane array on a temporary substrate;
after placing the plurality of preformed connections and the ground plane array on the temporary substrate, forming a molded panel over the temporary substrate and around the ground plane array and the plurality of preformed connections to yield an Embedded Ground Plane (EGP) array and a plurality of preformed EGP connections, respectively;
after forming the molded panel, removing material from a backside of the molded panel to thin the molded panel and expose the plurality of preformed EGP connections;
after removing material from the backside of the molded panel, removing the temporary substrate to expose a frontside of the molded panel;
after removing the temporary substrate, producing one or more Redistribution Layers (RDLs) over the frontside of the molded panel; and
after producing the one or more RDLs over the frontside of the molded panel, singulating the molded panel and severing the ground plane array through the plurality of spars to yield a plurality of FO-WLPs, each of the plurality of FO-WLPs including a molded package body containing a singulated EGP separated from the EGP array and one or more of the preformed EGP connections.
2. The method of claim 1 further comprising providing an Electromagnetic Interference (EMI) shield on the backside of the molded package body and electrically coupled to the singulated EGP through the one or more preformed EGP connections.
3. The method of claim 1 further comprising depositing at least one continuous electrically-conductive layer over the backside of the molded panel and in ohmic contact with the plurality of preformed EGP connections, the at least one continuous electrically-conductive layer forming Electromagnetic Interference (EMI) shields included within the plurality of FO-WLPs when the molded panel is singulated.
4. The method of claim 1 wherein bonding the plurality of preformed ground plane connections to the ground plane array, comprises:
dispensing an electrically-conductive material in a predetermined pattern over the ground plane array; and
curing the electrically-conductive material to produce the plurality of preformed connections.
5. The method of claim 4 wherein dispensing comprises:
positioning a stencil over the ground plane array, the stencil having stencil openings defining a shape and position of the plurality of preformed connections; and
applying the electrically-conductive material into the stencil openings and onto the ground plane array.
6. The method of claim 4 wherein the electrically-conductive material comprises a metal particle-filled adhesive, and wherein the curing comprises sintering the metal particle-filled adhesive to produce the plurality of preformed connections.
7. The method of claim 1 wherein the plurality of preformed connections comprise a plurality of electrically-conductive structures, and wherein bonding comprises bonding the plurality of electrically-conductive structures to the ground plane array utilizing an electrically-conductive adhesive prior to forming the molded panel.
8. The method of claim 1 wherein forming comprises forming the molded panel around the ground plane array, the plurality of preformed connections, and a plurality of electrical components positioned in openings provided in the ground plane array.
9. The method of claim 8 wherein the plurality of preformed connections comprise substantially continuous walls extending around the openings provided in the ground plane array and a semiconductor die positioned therein.
10. The method of claim 9 further comprising:
positioning the electrical components in the openings and surrounded by the substantially continuous walls, wherein the electrical components are selected from semiconductor die and discrete components, and wherein at least some of the electrical components are configured to operate at radio frequencies (RF); and
forming at least one Electromagnetic Interference (EMI) shield on the backside of the molded package body cooperating with the substantially continuous walls to form an EMI cage enclosing the electrical components.
11. The method of claim 1 further comprising producing the plurality of preformed connections as a plurality of vertically-extending columns projecting upwardly from selected locations of the ground plane array.
12. The method of claim 1 wherein bonding comprises:
aligning a stencil with the ground plane array;
after aligning the stencil to the ground plane array, utilizing a squeegee to applying an electrically-conductive material over the stencil and into openings provided in the stencil;
curing the electrically-conductive material to form the plurality of preformed connections; and
after curing, removing the stencil from over the ground plane array.
13. The method of claim 1 wherein removing material comprises thinning the backside of the molded panel to expose portions of the plurality of preformed EGP connections, while imparting the backside with a substantially planar geometry; and
wherein the method further comprises, after thinning, forming an Electromagnetic Interference (EMI) shield on the backside of the molded package body and in electrical contact with the exposed portions of the plurality of preformed EGP connections.
14. The method of claim 1 further comprising:
selecting the plurality of ground plane structures to comprise rectangular bodies; and
forming the plurality of preformed connections to comprise continuous walls extending over and around the rectangular bodies of the plurality of ground plane structures.