Packaged radio-frequency module having wirebond shielding

Abstract

According to one exemplary embodiment, an overmolded package includes a component situated on a substrate. The overmolded package further includes an overmold situated over the component and the substrate. The overmolded package further includes a wirebond cage situated over the substrate and in the overmold, where the wirebond cage surrounds the component, and where the wirebond cage includes a number of wirebonds. The wirebond cage forms an EMI shield around the component. According to this exemplary embodiment, the overmolded package further includes a conductive layer situated on a top surface of the overmold and connected to the wirebond cage, where the conductive layer forms an EMI shield over the component.

What is claimed is: 
     
         1 . A packaged radio-frequency (RF) module comprising:
 a packaging substrate having a reference potential layer;   an RF component positioned over the packaging substrate;   an overmold implemented over the packaging substrate to substantially encapsulate the RF component, the overmold including an upper surface;   a conductive layer implemented on the upper surface of the overmold; and   a plurality of wirebonds implemented on the packaging substrate, each of the plurality of wirebonds having a first end electrically connected to the reference potential layer and a second end electrically connected to the conductive layer, the plurality of wirebonds arranged in a pattern relative to the RF component to yield electromagnetic shielding with respect to the RF component.   
     
     
         2 . The packaged RF module of  claim 1  wherein a combination of the conductive layer, the reference potential layer, and the plurality of wirebonds results in electromagnetic shielding with respect to a volume that covers the RF component. 
     
     
         3 . The packaged RF module of  claim 2  wherein the pattern of the wirebonds defines a boundary of the volume. 
     
     
         4 . The packaged RF module of  claim 1  wherein the pattern of the wirebonds includes a segment that separate a region associated with the RF component and another region on the packaging substrate, such that the pattern of the wirebonds provides the electromagnetic shielding between the region and the other region. 
     
     
         5 . The packaged RF module of  claim 1  wherein the pattern of the wirebonds includes a perimeter around the RF component, such that the pattern of the wirebonds provides the electromagnetic shielding between a region within the perimeter and a region outside of the perimeter. 
     
     
         6 . The packaged RF module of  claim 5  wherein the perimeter is substantially at or near the perimeter of the packaging substrate. 
     
     
         7 . The packaged RF module of  claim 1  wherein the packaging substrate includes a laminate substrate or a ceramic substrate. 
     
     
         8 . The packaged RF module of  claim 1  wherein the RF component is positioned directly on the packaging substrate. 
     
     
         9 . The packaged RF module of  claim 1  wherein the RF component includes a semiconductor die having an RF circuitry. 
     
     
         10 . The packaged RF module of  claim 1  wherein the RF component includes a passive device. 
     
     
         11 . The packaged RF module of  claim 1  further comprising a plurality of bond pads implemented on the packaging substrate and electrically connected to the reference potential layer, such that the first end of each of one or more of the plurality of wirebonds is attached to a corresponding bond pad. 
     
     
         12 . The packaged RF module of  claim 11  wherein each wirebond has associated with it a corresponding bond pad. 
     
     
         13 . The packaged RF module of  claim 11  wherein each wirebond extends generally upward between the corresponding bond pad and the conductive layer. 
     
     
         14 . The packaged RF module of  claim 13  wherein each wirebond is substantially straight. 
     
     
         15 . The packaged RF module of  claim 1  wherein a spacing between an adjacent pair of wirebonds is selected to provide the electromagnetic shielding for a particular frequency or range of frequencies. 
     
     
         16 . The packaged RF module of  claim 15  wherein the spacing is substantially uniform among the adjacent pairs of wirebonds. 
     
     
         17 . The packaged RF module of  claim 1  wherein the conductive layer includes a sprayed-on conductive layer. 
     
     
         18 . A radio-frequency (RF) device comprising:
 a circuit board; and   a packaged device mounted on the circuit board, the packaged device including a packaging substrate having a reference potential layer, and an RF component positioned over the packaging substrate, the packaged device further including an overmold implemented over the packaging substrate to substantially encapsulate the RF component, the overmold including an upper surface, the packaged device further including a conductive layer implemented on the upper surface of the overmold, the packaged device further including a plurality of wirebonds implemented on the packaging substrate, each of the plurality of wirebonds having a first end electrically connected to the reference potential layer and a second end electrically connected to the conductive layer, the plurality of wirebonds arranged in a pattern relative to the RF component to yield electromagnetic shielding with respect to the RF component.   
     
     
         19 . The RF device of  claim 17  wherein the RF device is a cellular phone. 
     
     
         20 . The RF device of  claim 17  wherein the electromagnetic shielding includes either or both of shielding between a region on the packaging substrate associated with the RF component and another region on the packaging substrate, and shielding between a region on the packaging substrate associated with the RF component and another region exterior to the packaged device. 
     
     
         21 . A shielded radio-frequency (RF) module comprising:
 a packaging substrate having a ground;   a conductive layer implemented over a region on the packaging substrate; and   a plurality of wirebonds configured to provide an electrical connection between the conductive layer and the ground, the plurality of wirebonds arranged in a pattern to yield electromagnetic shielding with respect to the region.