HK1201378B - Apparatus and methods related to conformal coating implemented with surface mount devices - Google Patents

Description

Device and method for conformal coating using surface mount devices

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Application No. 61/812,610, filed on April 16, 2013, entitled “RADIO-FREQUENCY SHIELD GROUNDPATH THROUGH A SURFACE MOUNT DEIVCE,” and U.S. Provisional Application No. 61/817,295, filed on April 29, 2013, entitled “TIERED PACKAGE-LEVEL RADIO-FREQUNCY SHIELDING,” the disclosures of each of which are hereby expressly incorporated herein by reference in their entirety.

Technical Field

The present disclosure generally relates to shielding of radio frequency modules.

Background Art

Electromagnetic (EM) fields may be generated from or have an undesirable effect on the area of a radio frequency (RF) device, such as an RF module. This EM interference (EMI) can degrade the performance of wireless devices using the RF module. Some RF modules may be provided with EM shielding to address these EMI-related performance issues.

Summary of the Invention

In some embodiments, the present disclosure relates to a radio frequency (RF) module comprising a package substrate configured to accommodate a plurality of components. The RF module further comprises an RF component mounted on the package substrate and configured to facilitate processing RF signals. The RF module further comprises an RF shield disposed relative to the RF component. The RF shield is configured to provide shielding for the RF component. The RF shield comprises a plurality of shielding wires and at least one shielding assembly. The at least one shielding assembly is configured to replace one or more shielding wires.

In some embodiments, the RF module may further include a conductive path implemented under a plurality of shielding bond wires. The conductive path may be electrically connected to the shielding bond wires and a ground plane within the package substrate. The RF shield may include at least one shielding bond wire arranged along a selected edge of the package substrate. The selected edge may be substantially free of shielding bond wires and conductive paths. The selected edge may be substantially free of margin for accommodating shielding bond wires and conductive paths, thereby reducing the overall lateral area of the package substrate.

In some embodiments, the shield assembly may include an upper surface and a conductive feature implemented on the upper surface. The conductive feature may be electrically connected to a ground plane of the RF shield through the shield assembly. An upper portion of the conductive feature on the shield assembly may be electrically connected to an upper conductive layer of the RF shield. The upper conductive layer may also be electrically connected to an upper portion of a shield bond wire. The RF module may further include an overmold structure that encapsulates the shield bond wire and at least a portion of the shield assembly, the overmold structure may include an upper surface that exposes an upper portion of the shield bond wire and an upper portion of the conductive feature.

In some embodiments, the shielding bond wires may include a filter device, such as a CSSD filter.

According to some embodiments, the present disclosure relates to a method for manufacturing a radio frequency (RF) module. The method includes providing a package substrate configured to accommodate a plurality of components. The method further includes mounting an RF component on the package substrate, wherein the RF component is configured to facilitate processing RF signals. The method further includes forming an RF shield relative to the RF component. The RF shield is configured to provide shielding for the RF component. The RF shield includes a plurality of shielding wires and at least one shielding assembly. The at least one shielding assembly is configured to replace one or more shielding wires.

In some embodiments, forming the RF shield includes installing at least one shield assembly along a selected edge of the package substrate. The selected edge may be substantially free of shielding wire bonds. The selected edge may be substantially free of excess space for accommodating shielding wire bonds, thereby reducing the overall lateral area of the package substrate.

In some embodiments, the present disclosure relates to a wireless device comprising an antenna and a module in communication with the antenna. The module is configured to facilitate either or both transmission and reception of RF signals by the antenna. The module includes a packaging substrate configured to accommodate a plurality of components. The module further includes an RF component mounted on the packaging substrate and configured to facilitate processing of RF signals. The module further includes an RF shield disposed relative to the RF component. The RF shield is configured to provide shielding for the RF component. The RF shield includes a plurality of shielding wires and at least one shielding assembly. The at least one shielding assembly is configured to replace one or more shielding wires.

According to some embodiments, the present disclosure relates to a radio frequency (RF) module comprising a package substrate configured to accommodate a plurality of components and including a ground plane. The RF module further comprises a conductive layer implemented on the package substrate. The RF module further comprises a surface mount device (SMD) mounted on the package substrate. The SMD is configured to electrically connect the conductive layer and the ground plane, thereby providing RF shielding between a first and a second region surrounding the SMD.

In some embodiments, the first region may be on the package substrate, and the second region may be outside the module. In some embodiments, each of the first and second regions may be on the package substrate.

In some embodiments, the SMD may include a functional component. The functional component may include an upper connection feature electrically contacting the conductive layer, a lower connection feature electrically contacting the ground plane, and at least one interconnection feature configured to electrically connect the conductive layer and the ground plane. The functional component may include a functional tube core, whereby the upper connection feature includes a metal layer formed on one side of the tube core. At least one interconnection feature may include at least one conductive via passing through the tube core. The lower connection feature may include a contact feature electrically connecting the conductive via passing through the tube core to the ground plane. The tube core may include a radio frequency (RF) filter, such as a tube core-sized surface acoustic wave (SAW) device (CSSD). The tube core may be mounted on the surface of the package substrate in an orientation flipped relative to its designed direction of use.

In some embodiments, the module may be substantially free of shielding wire bonds. In some embodiments, the module may include a plurality of shielding wire bonds configured to provide shielding functionality with the SMD.

In some embodiments, the present disclosure relates to a method for manufacturing a radio frequency (RF) module. The method includes providing a package substrate, wherein the package substrate is configured to accommodate a plurality of components and includes a ground plane. The method further includes mounting a surface mount device (SMD) on the package substrate. The method further includes forming or providing a conductive layer above the SMD, such that the SMD electrically connects the conductive layer and the ground plane, thereby providing RF shielding between a first and a second region around the SMD.

In some embodiments, mounting the SMD includes flipping the SMD from its designed orientation for use, the SMD including the conductive features facing upward and in electrical contact with the conductive layer in the flipped orientation.

According to some embodiments, the present disclosure relates to a wireless device comprising an antenna and a module communicating with the antenna. The module is configured to facilitate processing of RF signals passing through the antenna. The module includes a package substrate configured to accommodate multiple components and having a ground plane. The module further includes a conductive layer implemented on the package substrate. The module further includes a surface mount device (SMD) mounted on the package substrate. The SMD is configured to electrically connect the conductive layer and the ground plane, thereby providing RF shielding between the first and second areas around the SMD.

In some embodiments, the present disclosure relates to a method for forming a conductive path for a radio frequency (RF) module. The method includes identifying a location of a surface mount device (SMD) mounted on a package substrate and sealed by an overmold. The method further includes forming an opening through the overmold in an area above the SMD, such that the opening has a sufficient depth to expose at least a portion of the SMD surface. The method further includes forming a conformal layer on the overmold, such that the conformal layer fills at least a portion of the opening to provide a conductive path between a portion of a conductive layer outside the opening and the surface of the SMD.

In some embodiments, each of the conformal layer and the exposed portion of the surface of the SMD may comprise a conductive layer, such conductive path comprising an electrical conductive path. Forming the opening may comprise using a laser ablation overmold. Forming the conformal layer may comprise applying a metallic paint.

According to some embodiments, the present disclosure relates to a method for manufacturing a radio frequency (RF) module. The method includes providing a package substrate configured to accommodate a plurality of components. The method further includes mounting a surface mount device (SMD) on the package substrate, the SMD including a metal layer facing upward when mounted. The method further includes forming an overmold on the package substrate so that the overmold covers the SMD. The method further includes forming an opening through the overmold in an area above the SMD to expose at least a portion of the metal layer. The method further includes forming a conductive layer on the overmold so that the conductive layer fills at least a portion of the opening to provide a conductive path between the conductive layer and the metal layer of the functional component.

In some embodiments, the forming of the openings may include ablating the overmold using a laser.The forming of the conductive layer may include applying a metallic paint.

In some embodiments, the method may further include forming a shielding bond wire on the package substrate before forming the overmold. The shielding bond wire may have a height greater than a height of the SMD. The overmold may have a height substantially equal to or greater than a height of the shielding bond wire.

In some embodiments, the method may further include removing an upper portion of the overmold before forming the opening to expose the top of the shielding wire bond but still cover the SMD. Removing the upper portion of the overmold may include an ablation process, such as micro-ablation.

In some embodiments, the method may further include removing residue resulting from the formation of the opening after forming the opening. Removing the residue may also result in removing additional material from the overmold, thereby further exposing the shielding wires. Removing the residue may include an ablation process, such as micro-ablation.

In some embodiments, the method may further include cleaning the exposed surface of the overmold and the metal layer of the SMD before forming the conductive layer.

In some embodiments, the SMD includes functional components that can be configured to help process RF signals.

According to some embodiments, the present disclosure relates to a radio frequency (RF) module comprising a package substrate configured to accommodate a plurality of components, and a surface mount device (SMD) mounted to the package substrate. The SMD includes a metal layer that faces upward when mounted. The RF module further includes an overmold formed on the package substrate, the overmold being sized to cover the SMD. The RF module further includes an opening defined by the overmold in an area above the SMD, the opening having a depth sufficient to expose at least a portion of the metal layer. The RF module also includes a conductive layer formed above the overmold, the conductive layer being configured to fill at least a portion of the opening to provide an electrical path between the conductive layer and the metal layer of the SMD.

In some embodiments, the SMD includes a functional component. The functional component may include an RF filter formed on the die. The RF filter may include a plurality of conductive vias passing through the die, at least some of the conductive vias being electrically connected to the metal layer and contact features on the underside of the RF filter. The contact features on the underside of the RF filter may be electrically connected to a ground plane of the package substrate, such that the conductive layer above the overmold is electrically connected to the ground plane through the RF filter. In some embodiments, the RF module may further include a plurality of shielding wire bonds arranged relative to the RF filter, the shielding wire bonds being configured to facilitate electrical connection between the conductive layer and the ground plane.

In some embodiments, the opening may include a sidewall having a chamfered profile such that the angle between the sidewall and the surface of the overmold has a value greater than 90 degrees, thereby facilitating improved uniformity of the conductive layer transition between the opening and the surface of the overmold. The conductive layer may include, for example, a layer formed by a metallic paint.

In some embodiments, the present disclosure relates to a wireless device having an antenna and a module that communicates with the antenna. The module is configured to facilitate either or both of the transmission and reception of RF signals through the antenna. The module includes a package substrate configured to accommodate a plurality of components. The module also includes a surface mount device (SMD) mounted on the package substrate. The SMD includes a metal layer that faces upward when installed. The module also includes an overmold formed above the package substrate, the size of the overmold being formed to cover the SMD. The module also includes an opening defined by the overmold in an area above the SMD, such that the opening has a depth sufficient to expose at least a portion of the metal layer. The module also includes a conductive layer formed above the overmold. The conductive layer is configured to fill at least a portion of the opening to provide an electrical path between the conductive layer and the metal layer of the SMD.

In some embodiments, the SMD may be a functional component. The functional component includes, for example, an RF filter. The wireless device may be a cellular phone configured to operate in a cellular frequency band associated with the RF filter.

For purposes of summarizing this disclosure, some aspects, advantages, and novel features of the present invention have been disclosed herein. It should be understood that not all of these advantages are necessarily achieved according to any particular embodiment of the present invention. Thus, the present invention may be implemented or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other advantages as may be taught or suggested herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 depicts a radio frequency (RF) module with an RF shield.

FIG2 illustrates a process that may be implemented to fabricate an RF module having one or more features as described herein.

3A-3C illustrate examples of how one or more RF components can be arranged in an RF module to provide shielding functionality.

FIG. 4 illustrates an exemplary module having a racetrack extending around the entire perimeter of a package substrate, and shielding wire bonds implemented on the racetrack.

FIG5 shows an example module including similar components as in FIG4; however, one side of the module is shielded by the RF components, thereby allowing a portion of the racetrack and corresponding shielding wire bonds to be omitted.

6A-6C illustrate examples of shielding wire bonds that may be implemented in an RF module.

7A-7D illustrate various examples of how ground connections may be made through one or more shield assemblies.

FIG. 8A illustrates an exemplary configuration of a module that may implement internal module RF shielding using one or more shielding assemblies.

FIG8B shows a more specific example of the shielding configuration of FIG8A .

9A depicts a cross-sectional view of an exemplary functional assembly that may be used as the shield assembly of FIGS. 8A and 8B .

FIG. 9B shows the functional components of FIG. 9A mounted on a package substrate in a desired orientation for use.

FIG. 10A shows that in some embodiments a functional assembly similar to the die of FIG. 9A can be flipped for mounting.

FIG. 10B shows a mounting configuration in which the flipped die is mounted on a package substrate.

FIG. 10C illustrates an exemplary packaging configuration in which overmold material 262 is shown laterally surrounding the mounted die of FIG. 10B .

FIG. 11A depicts an exemplary configuration for providing electrical connections between conductive layers on an RF module and a shield assembly.

FIG. 11B depicts a shielded electrical path that may be provided by the configuration of FIG. 11A .

12A-12E illustrate examples of how openings formed through an overmold layer can allow electrical connections to be formed between a conductive layer of an RF module and a conductive layer of a shield assembly.

13A-13F illustrate examples of how techniques such as laser ablation can be used to form openings through the overmold to facilitate electrical connection between the conductive layer of the module and the metal layer of the shield assembly.

FIG. 14 illustrates a process that may be implemented to achieve the exemplary module fabrication stages of FIGs. 13A-13F.

15A-15C illustrate examples of one or more arrangements of openings that may be implemented to facilitate electrical connections as described herein.

FIG16 depicts an example wireless device having one or more advantageous features described herein.

DETAILED DESCRIPTION

The headings provided herein, if any, are for convenience only and do not necessarily affect the scope and meaning of the claimed invention.

Disclosed herein are various devices and methods for providing radio frequency (RF) isolation or shielding for active or passive RF devices. For purposes of this description, it will be understood that RF may include electromagnetic signals having a frequency or frequency range associated with wireless devices. RF may also include electromagnetic signals radiated within an electronic device, whether or not the electronic device operates as a wireless device. RF may also include signals or noise associated with typical electromagnetic interference (EMI) effects.

For purposes of this description, it will be understood that such RF devices may include devices configured to operate in the RF range to facilitate transmission and/or reception of RF signals, as well as devices that may affect other devices through RF signals or noise or be affected by RF signals or noise. Non-limiting examples of such RF devices may include semiconductor dies with or without RF circuitry. Non-limiting examples of such RF-related devices may include discrete devices such as inductors and capacitors, or even a section of a conductor.

For the purposes of this description, it will be understood that the terms isolation and shielding can be used interchangeably, depending on the context of use. For example, a shielded RF device can include a condition in which RF signals from another source are partially or completely blocked. In another example, an isolated RF device can include a condition in which RF signals (e.g., noise and/or actively generated signals) are partially or completely blocked from reaching other devices. Unless the context of use clearly indicates otherwise, it will be understood that each of the terms shielding and isolation can include either or both of the aforementioned functions.

1 depicts an RF module 100 having an RF shield 102. The RF shield 102 is shown as including a portion 104 where one or more components can be positioned and/or configured to provide a shielding function. Various examples of how such component portions can be configured are described in greater detail herein.

1 , an exemplary module 100 may include a package substrate 120 (e.g., a laminate substrate) configured to house a plurality of components. Such components may include, for example, a die 122 having an integrated circuit (IC) such as an RF circuit. One or more surface mount devices (SMDs) 124 may also be mounted on the package substrate 120 to facilitate various functions of the module 100. In some embodiments, the module 100 may further include an overmold structure that encapsulates some or all of the RF shield 102, the component portion 104, the die 122, and the SMDs 124.

FIG2 shows a process 110 that can be implemented to manufacture a module (e.g., module 100 in FIG1 ) having one or more features as described herein. In block 112, an RF component can be provided. In block 114, the RF component can be positioned and mounted on a package substrate to provide an RF shielding function together with shielding wires. Such shielding wires can be formed before or after the RF component is installed. Examples of the placement of such RF components are described in more detail herein. In block 116, one or more ground connections that facilitate the RF shielding function can be formed. Examples of such ground connections are described in more detail herein. Although various examples are described herein in the context of shielding wires, it will be understood that one or more features of the present disclosure can also be implemented without such shielding wires, using other types of RF shielding technology, without using any other shielding technology, or any combination thereof.

3A-3C illustrate non-limiting examples of how one or more RF components 130 can be mounted to form one or more shielding portions 104 around or near the perimeter of the module 100. Such shielding portions, along with a plurality of shielding wire bonds 106, can form an RF shield and provide RF shielding between the inner and outer sides of the RF shield. Although described in the context of RF shielding of an area generally surrounded by the RF shield, it will be understood that one or more features of the present disclosure can also be implemented to provide RF shielding between two areas both on the module 100.

FIG3A illustrates that in some embodiments, a shielding portion 104 can be provided on selected sides along the perimeter of the module 100. A plurality of shielding wire bonds 106 can be provided on the remaining sides of the perimeter. An exemplary shielding portion 104 is shown as including first and second components 130 a, 130 b. A greater or lesser number of components can be included in the shielding portion 104. Such components can be active RF components, passive components, or some combination thereof.

FIG3B illustrates that in some embodiments, shielding sections 104a, 104b may be provided on more than one side of module 100. In the example, first shielding section 104a is shown as including first and second components 130a, 130b; second shielding section 104b is shown as including a single component 130c. Each of shielding sections 104a, 104b may contain a greater or lesser number of components. Such components may be active RF components, passive components, or some combination thereof. In the example of FIG3B , multiple shielding wire bonds 106 may be provided on the remaining sides of the perimeter.

FIG3C illustrates that in some embodiments, shield portion 104 does not necessarily occupy an entire side. For example, shield portion 104 with component 130 is shown positioned along a selected side, with shielding wire bonds 106 to the left and right of component 130. It will be appreciated that, in some embodiments, such shielding wire bonds 106 may be positioned to the left or right of component 130. Furthermore, more than one component (active, passive, or some combination thereof) may be positioned on a given side of a module; and such components may be positioned with or without one or more shielding wire bonds along that side.

In some embodiments, using one or more shielding components instead of one or more shielding wire bonds can provide advantageous features such as reducing the module area. For example, consider the following RF shielding configuration in which the shielding wire bonds are connected to the ground plane via a conductive path that extends substantially along the entire perimeter of the module. Such a configuration typically requires a margin along the perimeter to accommodate the conductive path and the shielding wire bonds. Therefore, by providing one or more components along a given side of the module and forming a ground connection facilitated by such components, the path and the corresponding shielding wire bonds can be removed from the given side. Since the margin along the given side is no longer required, that portion of the module can be removed, thereby reducing the overall lateral area of the module.

4 illustrates, by way of example, an exemplary module 140 having a conductive racetrack 144 extending around the entire perimeter of a package substrate 142. A plurality of shielding wire bonds 106 are shown provided along the line defined by the racetrack 144. Various components, including an integrated circuit (IC) die 122 and filters 130a, 130b, are shown within the boundaries defined by the racetrack 144. As described herein, the margin desired or required outside of the racetrack 144 contributes to the overall lateral dimensions d1×d2 of the package substrate 142.

In FIG5 , an example module 150 is shown as including components similar to those in FIG4 (e.g., IC die 122 and filters 130 a, 130 b). However, while three of the four sides of package substrate 152 include paths 154 and a plurality of shielding wire bonds 106, a fourth side 156 of package substrate 152 (the right side in the example of FIG5 ) does not include any paths or shielding wire bonds. Therefore, fourth side 156 does not require the margins found on the other three sides. Thus, the area required for the paths and shielding wire bonds on the fourth side can be removed from package substrate 152.

In the specific example of FIG5, dimension d2 can be substantially the same as in the example of FIG4. However, dimension d1 of FIG4 can now be reduced by Δd to produce a reduced dimension d3. In some embodiments, this reduction by Δd can generally be the area required to implement the fourth side path and the corresponding shield bond wire.

5 , filters 130 a, 130 b may be, for example, chip-scale SAW (surface acoustic wave) devices (CSSDs), such as commercially available Taiyo Yuden CSSD filters. Each filter may include or be equipped with a grounded top surface that may be used to form one or more electrical connections to facilitate RF shielding functionality.

In some embodiments, the RF shielding wire bonds 106 used with the shield assembly 130 described herein can be configured in a variety of ways. Figures 6A-6C illustrate non-limiting examples of such shielding wire bonds 106. In Figure 6A, shielding wire bonds 106 having a deformable configuration are shown as being formed on pads 52a, 52b on a package substrate 54 (e.g., a laminate substrate). Additional details regarding such wire bond configurations can be found in International Publication No. WO 2010/014103 (International Application No. PCT/US2008/071832, filed July 31, 2008, entitled "SEMICONDUCTOR PACKAGE WITH INTERGRATED INTERFERENCE SHIELDING AND METHOD OF MANUFACTURE THEREOF"), the disclosure of which is incorporated herein by reference in its entirety.

In FIG6B , arched shielding wire bonds 50 are shown formed on bonding pads 52 a, 52 b on a package substrate 54 (e.g., a laminate substrate). Additional details regarding this wire bond configuration can be found in U.S. Patent No. 8,399,972, entitled “OVERMOLDED SEMICONDUCTOR PACKAGE WITH A WIREBOND CAGE FOR EMISHIELDING,” the disclosure of which is incorporated herein by reference in its entirety.

FIG6C shows that in some embodiments, the shielding bond wire need not be curved or have endpoints that start and end on the package substrate. A bond wire structure 106 that starts on the package substrate 54 and ends at a location above the package substrate 54 is shown formed on the bonding pad 52. Further details of this bond wire configuration can be found in the aforementioned U.S. Patent No. 8,399,972. Other configurations of shielding bond wires can also be used.

7A-7D illustrate various non-limiting examples of how ground connections can be made through one or more shielding assemblies 130. In the example configuration 160 of FIG. 7A , the shielding assembly 130 (e.g., an RF filter) is depicted as being mounted on the package substrate 56 via contact pads 162 a, 162 b. In the package substrate, at least one such contact pad can be a ground pad electrically connected to a ground plane. The upper surface of the shielding assembly 130 is shown as including a conductive layer 164. In some embodiments, such a conductive layer 164 can be electrically connected to the ground pad and, thereby, to the ground plane.

Positioned relative to the shield assembly 130 are exemplary shielding bond wires 106 formed on the pads 52a, 52b. As described in the above-referenced U.S. Patent No. 8,399,972, the bond pads can be electrically connected to a ground plane in the package substrate. Also as described in the above-referenced U.S. Patent No. 8,399,972, the upper portion 58 of the shielding bond wires 106 can be exposed from the overmold structure 56 to allow for electrical connection to the conductive layer 60. This arrangement of the conductive layer 60, the shielding bond wires 106, and the ground plane allows for shielding of RF signals, RF noise, electromagnetic interference (EMI), etc. between interior and exterior areas and/or between selected areas within the module boundary.

7A , the conductive layer 60 may be electrically connected to the conductive layer 164 of the shield assembly 130 . Thus, the aforementioned shielding arrangement may be extended to areas where the shield assembly 130 replaces one or more shielding wire bonds 106 .

In the example shown, the height of the upper surface of the conductive layer 164 is depicted as h. In some embodiments, the shield bond wires 106 can be appropriately sized so that their height is also approximately h.

In the example of FIG7A , conductive layer 164 is depicted as a single layer extending laterally to substantially cover shield assembly 130. FIG7B illustrates that in some embodiments, such a conductive layer need not cover the entire upper portion of shield assembly 130. In example configuration 170, conductive layer 174 is shown covering only a portion of the upper surface of shield assembly 130. The remaining area is shown as being covered by an overmold structure.

In some embodiments, each of the conductive layers 164, 174 of Figures 7A and 7B can be a single continuous sheet. In some embodiments, each of the conductive layers 164, 174 can include multiple conductive features electrically connected to a ground pad. Other configurations can also be implemented.

7C shows that in some embodiments, the heights of the shielding wirebond and the shield assembly do not need to be the same. In the example configuration 180, the shielding wirebond 106 is depicted as having a height h1, and the upper surface of the conductive layer 164 above the shield assembly 130 is depicted as having a height h2 that is less than h1. This configuration may occur when, for example, the shield assembly 130 has a relatively low profile.

If the height difference h3 (h1 minus h2) is large enough, it may be undesirable or impractical to form an electrical connection between conductive layers 60 and 164 through a solid conductive layer. To form an electrical connection, one or more reduced-size shield bond wires 182 may be provided on conductive layer 164 so that the tops 184 of the bond wires 182 are in electrical contact with conductive layer 60. In some embodiments, the shape of the reduced-size shield bond wires 182 may be similar to the shape of shield bond wire 106. In some embodiments, the two shapes may be different.

FIG7D illustrates that in some embodiments, the additional height bridged by the multiple reduced-size shielding wire bonds 182 in the example of FIG7C can also be occupied in other ways. In the example configuration 200, the additional shielding assembly 202 is shown positioned above the shielding assembly 130. A conductive layer 206 on the upper surface of the additional assembly 202 is shown in electrical contact with the conductive layer 60, and the conductive layer 206 can be electrically connected to a ground pad (e.g., either or both of the pads 204a, 204b). The pads 204a, 204b are shown in electrical contact with the corresponding conductive layers 164a, 164b. As described herein, either or both of the conductive layers 164a, 164b can be electrically connected to a ground plane.

In some embodiments, additional component 202 may be an active or passive device that facilitates the operation of the module. In some embodiments, additional component 202 may be a dummy device configured to provide the aforementioned electrical bridge between conductive layers 60 and 164 .

In various examples described with reference to Figures 1-7, RF shielding functionality includes some combination of one or more shielding components (130) and a plurality of shielding wire bonds (106). Further, some such combinations are described in the context of generally surrounding an area on a package substrate to provide RF shielding functionality between an interior and exterior of the area.

As described herein, it will be appreciated that one or more features associated with the use of shielding assemblies (130) may be implemented in other configurations. For example, one or more shielding assemblies (130) (with or without shielding wire bonds) may be implemented to provide RF shielding between first and second regions of the same module without necessarily defining a generally enclosed area. In such configurations where the intra-module RF shielding does not include shielding wire bonds, the use of the necessary components as shielding assemblies and the absence of shielding wire bonds may make the packaging process more efficient and save costs.

FIG8A illustrates an example configuration of a module 100 in which intra-module RF shielding may be implemented using one or more shield assemblies 130. Three example shield assemblies 130a, 130b, and 130c are shown providing RF shielding 210 between a first region "A" and a second region "B," both of which are part of the same module 100. In the example shown, the module 100 does not include any shielding wire bonds. However, shielding wire bonds may be implemented to provide RF shielding between, for example, interior and exterior locations of the module 100.

FIG8B shows a more detailed example of the intra-module shielding configuration of FIG8A . An exemplary front-end module (FEM) 100 is shown including a power amplifier (PA) die having PA circuitry configured to provide multi-mode multi-band (MMMB) capability. Operation of such PA circuitry in different cellular frequency bands and/or different modes may be facilitated by one or more band switches, filters, duplexers, and antenna switches.

In the example shown in FIG8B , it is assumed that a band switch 212 located in one region (e.g., region A) radiates RF signals and/or noise that affect the operation of a duplexer 214 (e.g., a B4 band duplexer) located in another region (e.g., region B). This known pair of components can be separated within the module to the extent possible or practical; however, it may be desirable to protect the B4 duplexer 214 from the radiated RF signals/noise from the band switch 212.

In some embodiments, RF filter devices can be used as shielding components. For example, some or all filters, such as B1 filter 130a, B3 filter 130b, B25 filter 130c, and B17 filter, can be positioned and configured as described herein to provide in-module shielding functionality. In the example shown in FIG8 , B1 filter 130a and B3 filter 130b can be located near B4 duplexer 214 to provide RF shielding from the effects of RF radiation (as depicted by arrow 216) from band switch 212.

In some embodiments, some or all of the shielding components 130 of Figures 8A and 8B can be functional components. For the purpose of description, it will be understood that a functional component can include a device (active or passive) that is part of the RF design of the module and therefore provides some RF-related functions. As described herein, a filter device such as a CSSD filter can be such a functional component. It will also be understood that a functional component can include a device (active or passive) that may or may not be part of the RF design of the module, and the RF design of the module includes connection features through the device, around the device, or some combination thereof. For example, as described in more detail herein, such a device can include through-substrate vias that provide or can provide an electrical connection path between two opposing sides of the device. It will be understood that the aforementioned elements can also be used as the shielding components described herein with reference to Figures 1-7.

FIG9A depicts a cross-sectional view of an example functional assembly 130 that can be used as one of the functional assemblies of FIG8A and FIG8B . In FIG9A , the functional assembly 130 is oriented as intended for conventional use, with the metal layer 228 on one side of the die substrate 220 facing downward for mounting to the package substrate 232 ( FIG9B ). In some embodiments, this metal layer (228) can be used during die fabrication; however, the metal layer 228 may or may not be used in the finished die. In some embodiments, the metal layer 228 can function as a ground for the die.

The other side of the die substrate 220 is shown to include a plurality of electrical contact pads 226a, 226b, 226c. Some of the contact pads (eg, 226a, 226b) may be used for signals, power, etc.; some (eg, 226c) may be used as ground contacts.

As further shown in FIG. 9A , the functional component 130 may include a plurality of through-die vias 222 a, 222 b, 222 c, 222 d. In some embodiments, such vias may be configured to provide, for example, an electrical connection between two sides of the die, a thermal conduction path, or some combination thereof. In some embodiments, some of such vias may be used during die fabrication but may not be used in the finished die. In the example shown, via 222 c is shown as providing an electrical connection between contact pad 226 c and metal layer 228 (e.g., to provide a ground connection). Other vias (222 a, 222 b, 222 d) may be utilized to conduct heat to the metal layer to dissipate heat from the die.

9B , metal layer 228 can be secured (e.g., soldered) to ground pads 236 to physically mount the die and provide an electrical connection between the die's ground and the module's ground. The die's non-ground contact pads (e.g., 226 a, 226 b) can be electrically connected to their respective contact pads (e.g., 234 a, 234 b) on package substrate 232.

FIG10A shows that in some embodiments, a functional component 130 substantially identical or similar to the die of FIG9A can be flipped over so that the metal layer 228 is now facing upward. FIG10B shows a mounting configuration in which the flipped die is mounted on a package substrate 252. In some embodiments, the package substrate 252 can be configured with contact pads (e.g., 254a, 254b, 254c) to facilitate physical mounting (e.g., by soldering) and electrical connection to the contact pads (e.g., 226a, 226b, 226c) of their respective die. The contact pads 254a, 254b, 254c can be electrically connected to their respective module terminals or module ground via various connection features (not shown) within the package substrate 252 (e.g., a stacking substrate).

10B , vias (e.g., 222 a, 222 b, 222 d) that are not connected in the aforementioned manner can be electrically grounded, for example, by one or more ball joints 256 that are in turn electrically connected (not shown) to a module ground. In some embodiments, such a module ground can include one or more ground planes that provide RF shielding beneath the surface of the package substrate 252.

10C illustrates an exemplary packaging configuration 260 in which overmold material 262 is shown laterally surrounding the mounted die. Additionally, metal material 264 is shown formed or provided on overmold 262 (eg, as described with reference to FIG. 7 ) and in electrical contact with metal layer 228 of the die.

As shown in FIG10C , metal layer 264 electrically contacts the ground plane within package substrate 252 through the die's metal layer 228, one or more through-die conductive vias (e.g., 222 a, 222 b, 222 c, 222 d), and their respective die-to-package substrate connection features (e.g., 256, 226 c, 254 c). As shown, conductive vias 222 a, 222 b, 222 c, 222 d can provide lateral RF shielding functionality (e.g., inter-module shielding between regions A and B in FIG8A and 8B ), which can be enhanced by electrically connecting the upper (metal layer 264) shielding plane and the lower (ground plane) shielding plane.

10A-10C , it can be seen that the functional component 130 (e.g., a CSSD filter die) can provide dual functionality—one for filtering and another for providing RF shielding. Note also that the flipped mounting configuration can also eliminate the need to use bonding wires to electrically connect the pads of the functional component 130. In some cases, this absence of bonding wires can be advantageous. In some embodiments, and as described herein, a shielding assembly as described herein can be an assembly that provides or facilitates electrical connections for a shielding function and also serves as a functional component of circuitry associated with a corresponding module. Using such a shielding assembly for dual purposes can allow, for example, a reduction or optimization of the space required for a module.

As described herein, there may be situations where the height of the overmold structure is greater than the height of the shield assembly (e.g., the examples of Figures 7C and 7D). Figure 11A depicts an exemplary configuration 500 for providing an electrical connection 510 between the conductive layer 264 on the RF module 100 and the shield assembly 130. As described herein, this electrical connection can be formed by a layer of the overmold structure 262 that seals the shield assembly 130. The shield assembly 130 is shown mounted on a package substrate 252 that includes a ground plane 504. Utilizing the electrical connection 510 between an electrical node A associated with the conductive layer 264 and the shield assembly 130, an electrical path 502 can be formed between node A and a node B associated with the ground plane 504 (see Figure 11B). This electrical path may include the conductive layer 264, the electrical connection 510, one or more electrical paths on, around, and/or through the shield assembly 130, one or more electrical connections between the shield assembly 130 and the package substrate 252, and one or more electrical connections within the package substrate 252.

In some embodiments, shielding assembly 130 can be a functional assembly, such as an RF filter device. Such functional assemblies and examples of using the functional assemblies to provide RF shielding functionality are described in more detail herein.

12A-12E illustrate examples of how openings through the overmold layer may allow electrical connections ( 510 in FIG. 11 ) to be formed between the conductive layer 532 of the RF module and the conductive layer of the functional component 130 .

As described herein, functional components 130 may include devices (active or passive) that are part of the module's RF design and thus provide some RF-related functionality. Devices such as CSSD (Chip Scale SAW (Surface Acoustic Wave) Device) filters may be such functional components.

10A , FIG12A depicts a cross-sectional view of an exemplary functional assembly 130. In the example shown, the functional assembly 130 is shown flipped over so that the metal layer 228 faces upward. Some or all of the exemplary through-die conductive vias 222a-222d can be electrically connected to the metal layer 228. Some of these through-die conductive vias can be electrically connected to one or more contact pads 226 formed on the bottom surface of the functional assembly 130. Some of these contact pads 226 can be electrically connected to circuits (e.g., signal input, signal output, power) formed within the functional assembly 130.

Similar to FIG10B , FIG12B shows a mounting configuration in which the flipped die 130 is mounted on a package substrate 252. In some embodiments, the package substrate 252 may include contact pads (e.g., 254a, 254b, 254c) to facilitate physical mounting (e.g., by soldering) and electrical connection to their respective contact pads (e.g., 226a, 226b, 226c) on the die. The contact pads 254a, 254b, 254c may be electrically connected to their respective module terminals or module ground via various connection features (not shown) within the package substrate 252 (e.g., a laminate substrate).

As further shown in FIG12B , vias (e.g., 222a, 222b, 222d) that are not connected in the aforementioned manner can be electrically grounded, for example, by ball joints 256 that are in turn electrically connected (not shown) to module ground. Thus, metal layer 228 is electrically connected to module ground through some or all of the conductive vias. In some embodiments, such module ground can include one or more ground planes that provide RF shielding beneath the surface of package substrate 252.

12C shows an example configuration in which an overmold 262 has been formed on the package substrate 252 and covers the metal layer 228 of the flipped die 130. Therefore, for the example configuration shown in FIG12C , a conductive layer (not shown) formed on the overmold 262 will not make direct electrical contact with the metal layer 228.

FIG12D shows an example configuration 520 in which an opening 522 has been formed on the metal layer 228 through a portion of the overmold 262. The opening 522 can be formed so as to produce an exposed surface 524 on the upper portion of the metal layer 228. Such an opening can be formed using a variety of techniques, including, for example, laser drilling or ablation. An example of forming the opening by laser ablation is described in more detail herein. Although described in this context, it will be understood that other opening formation techniques (e.g., mechanical drilling or chemical etching) can also be used.

12E shows an example configuration 530 in which a conductive layer 532 has been formed over overmold 262 and opening 522. In some embodiments, conductive layer 532 may provide continuous coverage of the area surrounding opening 522, the walls of opening 522, and the surface 524 of metal layer 228 exposed through opening 522. Thus, conductive layer 532 as a whole may be in electrical contact with metal layer 228, and thereby with a ground plane (not shown) of the module.

13A-13F illustrate examples of how laser ablation can be used to form openings through the overmold to facilitate electrical connections between the conductive layer of the module and the metal layer of the functional component. FIG13A shows an example configuration in which a functional component 130, such as a filter device, and shielding wire bonds 106 are mounted to a package substrate 252. Although described in the context of implementing both the functional component 130 and the shielding wire bonds 106 together, it will be understood that one or more features associated with forming electrical connections through a portion of the overmold can also be implemented without the shielding wire bonds 106. It will also be understood that the functional component 130 includes an upper metal layer (e.g., 228 in FIG12).

13B illustrates an example stage of module fabrication in which an overmold 262 has been formed on the package substrate 252. The overmold 262 is shown as substantially encapsulating the shield bond wires 106. An upper surface 540 of the overmold 262 may or may not expose the tops of the shield bond wires 106 (58 in FIG. 13C).

In the example shown, the height of the shield bond wires 106 is greater than the height of the functional component 130. Thus, the overmold 262 is shown covering the upper surface of the functional component 130.

13C shows an exemplary stage in which material has been removed from the upper surface (540 in FIG. 3B ) to create a new upper surface 542. The amount of material removed can be selected so that the tops 58 of the shielding wire bonds 106 are sufficiently exposed to allow electrical connection to the conductive layer formed on the new upper surface 542. In some embodiments, this removal of material can be accomplished by micro-ablation.

13D shows a stage 550 where a laser beam 554 is applied to an area above the functional component 130 to melt the overmold material and form an opening 552. In some embodiments, the overmold material may include, for example, epoxy molding compounds (EMCs). For such exemplary materials, the opening may be formed using a laser having a wavelength in the range of, for example, 355 nm to 1060 nm.

In some embodiments, the laser beam 554 can be applied until the upper surface 556 (e.g., metal layer) of the functional component 130 is sufficiently exposed to form an electrical connection. With the example lasers described above, the beam at the operating power can generally be reflected from the metal surface 556. Thus, the likelihood of overburning substantially into or through the metal layer is reduced.

In some embodiments, the laser beam 554 can be focused to provide a desired transverse beam size, for example, at the ablation location. Such a focused beam can have a conical shape, thereby resulting in the opening 552 having a chamfered wall that forms an angle greater than 90 degrees with the upper surface 542. Such a chamfered profile can help to form improved coverage of the conductive layer.

13E illustrates an exemplary stage 560 in which the opening 552 formed by the laser can be cleaned, for example, to remove laser ablation residue on the surface 556. In some embodiments, such cleaning can be accomplished by microablation similar to the microablation example of FIG. 13C.

In some embodiments, the entire module (and, in the case where an array of modules is fabricated in a panel, the entire panel) can undergo a micro-ablation process to clean the openings 552. This exposure to micro-ablation can result in further removal of the overmold material, thereby creating a new surface 544. In some embodiments, approximately 1 to 5 μm of overmold material can be removed during this micro-ablation process.

In the example stages of performing microablation (FIGS. 13C to 13E), it will be understood that the example figures are not necessarily drawn to scale. Thus, the microablation associated with FIG. 13E may remove a greater or lesser amount of overmold material than the microablation of FIG. 13C.

13E shows that this further removal of the overmold material further exposes the shield bond wires 106. In some embodiments, this increase in the exposed portion of the shield bond wires 106 can help form an improved electrical connection with the conductive layer.

In some embodiments, a rinse process may be performed to remove residue from the micro-ablation process and prepare the surfaces ( 544 , 556 ) of the overmold 262 and the exposed metal layer of the functional component 130 .

13F illustrates an example stage 570 in which a conductive layer 572 has been applied to substantially cover the overmold surface 544, the walls 558 of the opening 552, and the exposed metal surface 556 of the functional component 130. The conductive layer 572 is also shown to have covered the exposed upper portions of the shield bond wires 106. Thus, the conductive layer 572 is now electrically connected to a ground plane (not shown) through the shield bond wires 106 and the functional component 130.

In some embodiments, conductive layer 574 can include a metallic paint applied by spraying. Various examples of such metallic paints are described in more detail, for example, in U.S. Patent Application Publication No. 2013/0335288, entitled “SEMICONDUCTOR PACKAGE HAVING A METAL PAINT LAYER,” the contents of which are incorporated herein by reference in their entirety.

FIG14 illustrates a process 600 that may be implemented to complete the example module manufacturing stages described with reference to FIG13A-13F . In block 602, a functional component may be mounted on a package substrate. In block 604, one or more shielding wire bonds may be formed relative to the functional component. In block 606, an overmold structure may be formed to seal the functional component and the shielding wire bonds. In block 608, a first ablation may be performed to expose the upper portions of the shielding wire bonds. In some embodiments, this ablation process may include a micro-ablation process. In block 610, an opening may be formed through the overmold to expose at least a portion of the metal layer of the functional component. In some embodiments, this opening may be formed by laser ablation. In block 612, a second ablation process may be performed to further expose the shielding wire bonds and remove residue from the surface of the exposed metal layer of the functional component. In some embodiments, this ablation process may include a micro-ablation process. In block 614, the exposed surface of the overmold and the metal layer surface may be cleaned. In block 616 , an upper conductive layer may be formed to cover the exposed portions of the shield bond wires and the exposed portions of the metal layer of the functional component. In some embodiments, the upper conductive layer may be formed by spray application of a metallic paint.

In some embodiments, additional details regarding the example stages of FIG. 13 and some of the process blocks of FIG. 14 can be found in U.S. Patent Application Publication No. 2013/0335288. It will be appreciated, however, that one or more features of the present disclosure may also be implemented with other configurations. For example, removal of the overmold material need not necessarily be performed by micro-ablation. In another example, formation of the upper conductive layer need not necessarily be performed by spray application of a metallic coating.

In various examples described herein, the opening (522 in FIG. 12 , and 552 in FIG. 13 ) is described in the context of forming one opening in the functional component (130). It will be understood that more than one opening may be formed and used to facilitate more than one electrical connection between the upper conductive layer and the functional component. For example, if a given functional component has a relatively large lateral dimension, it may be desirable to form multiple such electrical connections.

15A shows a plan view of the functional component 130 sealed by the overmold 262. An opening (522, 552) is shown formed to facilitate electrical connections as described herein. This opening may or may not be centered relative to the functional component 130.

15B shows an example configuration in which a plurality of openings (522, 552) are formed in the functional component 130. In some embodiments, such openings are generally arranged along selected lines.

15C shows that in some embodiments, the plurality of openings (522, 552) can also be arranged laterally in two dimensions. For example, the openings can be arranged in a two-dimensional array.

In various examples herein, a conformal conductive layer (e.g., 572 in FIG. 13F ) and its contact with the exposed metal surface of an SMD (e.g., 130) are described in the context of forming an electrically conductive path to facilitate a ground path between the conformal conductive layer and the ground plane of the package substrate. However, it will be understood that one or more features associated with such a conformal layer formed so as to contact the upper surface of the SMD can also be used to provide other conductive paths between the SMD and the conformal layer. For example, heat can be transferred from the SMD through its upper surface and reach the conformal layer by conduction. In such applications, either or both of the conformal layer and the upper surface of the SMD can be configured to provide good thermal conductivity and may or may not include electrical conductivity.

For the purposes of description herein, a surface mount device (SMD) may include any device that can be mounted on a substrate, such as a package substrate utilizing various surface mount technologies. In some embodiments, an SMD may include any device that can be mounted on a package substrate and has an upper surface. In some embodiments, such an upper surface may be larger than the upper portion of a bent wire bond. An SMD may include active and/or passive components; and such components may be configured for RF and/or other applications. The SMD is also referred to herein as, for example, an RF component, a component, a filter, a CSSD, a shielding component, a functional component, etc. It will be understood that these terms may be used interchangeably in their respective contexts.

In some embodiments, the devices and/or circuits having one or more features described herein may be included in an RF device such as a wireless device. Such devices and/or circuits may be implemented directly in the wireless device in a modular form as described herein, or in some combination thereof. In some embodiments, such a wireless device may include, for example, a cellular phone, a smartphone, a handheld wireless device with or without telephone functionality, a wireless tablet, and the like.

FIG16 illustrates an example wireless device 700 having one or more advantageous features described herein. In the context of a module 100 having one or more features as described herein, the module may be generally depicted by the dashed box 100 and may be implemented as a front-end module (FEM). Other modules within the wireless device 700 may also benefit from the implementation of one or more features as described herein.

PA (power amplifier) 712 can receive their respective RF signals from transceiver 710, which can be configured and operated to generate RF signals to be amplified and transmitted, and process received signals. Transceiver 710 is shown interacting with baseband subsystem 708, which is configured to provide conversion between data and/or voice signals suitable for the user and RF signals suitable for transceiver 710. Transceiver 710 is also shown connected to power management component 706, which is configured to manage power for operation of the wireless device. Such power management can also control the operation of baseband subsystem 708 and module 100.

Baseband subsystem 708 is shown connected to user interface 702 to facilitate providing various inputs and outputs of sound and/or data to and from the user. Baseband subsystem 708 may also be connected to memory 704, which is configured to store data and/or instructions to facilitate operation of the wireless device and/or provide stored information to the user.

In the example wireless device 700, the output of the PA 712 is shown as being matched (via respective matching circuits 714) and routed to the antenna 722 via a band select switch 716, their respective duplexers 718, and an antenna switch 720. In some embodiments, each duplexer 718 can allow for simultaneous transmit and receive operations (e.g., 722) using a common antenna. In FIG16, received signals are shown as being routed to an "Rx" path (not shown) that includes, for example, one or more low noise amplifiers (LNAs).

Many other wireless device configurations can utilize one or more of the features described herein. For example, a wireless device is not required to be a multi-band device. In another example, a wireless device can include additional antennas, such as a diversity antenna, and additional connectivity features, such as Wi-Fi, Bluetooth, and GPS.

Unless the context clearly requires otherwise, throughout the specification and claims, the words "comprises" and "comprising" and the like should be interpreted in an inclusive sense, and not in an exclusive or exhaustive sense; that is, in the sense of "including, but not limited to". As generally used herein, the word "coupled" means that two or more elements can be connected directly or through one or more intermediate elements. In addition, when used in this application, the words "herein", "above", "below" and words of similar meaning shall refer to this application as a whole and not to any particular part of this application. Where the context permits, words in the above specific embodiments that use the singular or plural may also include the plural or singular, respectively. When the word "or" refers to a list of two or more items, the word covers all of the following interpretations of the word: any item in the list, all items in the list, and any combination of items in the list.

The above detailed description of the embodiment is not intended to be exhaustive or to limit the invention to the precise form disclosed above. Although specific embodiments and examples of the present invention have been described above for illustrative purposes, various equivalent modifications may be within the scope of the present invention as will be appreciated by those skilled in the relevant art. For example, although processes or blocks are presented in a given order, alternative embodiments may perform routines with steps in different orders, or adopt systems with blocks, and may delete, move, add, subdivide, combine and/or modify some processes or blocks. Each of these processes or blocks may be implemented in various ways. In addition, although processes or blocks are sometimes shown as being performed serially, alternatively, these processes or blocks may be performed in parallel, or may be performed at different times.

The teachings of the invention provided herein can be applied to other systems, not necessarily the system described above.The elements and acts of the various embodiments described above can be combined to provide further embodiments.

Although certain embodiments of the present invention have been described, these embodiments are presented by way of example only and are not intended to limit the scope of the present disclosure. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions, and changes in the form of the methods and systems described herein may be made without departing from the spirit of the present disclosure. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the present disclosure.

Claims (20)

1. A method for manufacturing a radio frequency (RF) module, the method comprising: A packaging substrate configured to accommodate multiple components is provided, the packaging substrate including a ground plane; A surface mount device (SMD) is mounted on a packaging substrate. The SMD contains a metal layer facing upwards during mounting and includes an RF filter. An encapsulation mold is formed on the packaging substrate, which covers the SMD; An opening is formed in the area above the SMD, penetrating the overmolding, to expose at least a portion of the metal layer; and A conductive layer is formed on top of the overmolding, which fills at least a portion of the opening to provide an electrical path between the conductive layer, the metal layer of the SMD, and the ground plane. 2. The method of claim 1, wherein forming the opening comprises using laser ablation of the covering mold. 3. The method of claim 1, wherein forming the conductive layer comprises applying a metallic coating. 4. The method of claim 1, further comprising forming shielding bonding wires on the packaging substrate prior to forming the encapsulation mold. 5. The method of claim 4, wherein the shielding wire has a greater height than the SMD. 6. The method of claim 5, wherein the covering mold has a height substantially equal to or greater than the height of the shielding bonding wire. 7. The method of claim 6, further comprising removing the upper portion of the overlay mold before forming the opening to expose the top of the shielded solder wires while still covering the SMD. 8. The method of claim 7, wherein removing the upper part of the covering mold comprises an ablation process. 9. The method of claim 8, wherein the ablation process comprises microablation. 10. The method of claim 8, further comprising removing residues resulting from the formation of the opening after the opening has been formed. 11. The method of claim 10, wherein removing the residue further results in the removal of additional material from the encapsulation mold, thereby further exposing the shielding solder lines. 12. The method of claim 10, wherein removing the residue comprises an ablation process. 13. The method of claim 12, wherein the ablation process comprises microablation. 14. The method of claim 10, further comprising cleaning the exposed surfaces of the overlay mold and the metal layer of the SMD prior to forming the conductive layer. 15. A radio frequency (RF) module, comprising: A packaging substrate configured to accommodate multiple components, the packaging substrate including a ground plane; A surface mount device (SMD) mounted on a package substrate, the SMD including a metal layer facing upwards during mounting, and the SMD containing an RF filter; An encapsulation mold formed on a packaging substrate, the size of which is configured to cover the SMD; An opening defined by a cover mold in the area above the SMD, the opening having a depth sufficient to expose at least a portion of the metal layer; and A conductive layer is formed on top of the overmolding, the conductive layer being configured to fill at least a portion of the opening to provide an electrical path between the conductive layer, the metal layer of the SMD, and the ground plane. 16. The RF module of claim 15, wherein the SMD includes an RF filter formed on the die. 17. The RF module of claim 16, wherein the RF filter includes a contact feature on the opposite side of the metal layer, the contact feature being electrically connected to the metal layer and also connected to a ground plane of the package substrate, such that a conductive layer above the encapsulation is electrically connected to the ground plane through the RF filter. 18. The RF module of claim 15, wherein the opening includes a sidewall with a beveled profile such that the angle between the sidewall and the surface of the overlay mold has a value greater than 90 degrees, thereby contributing to improved uniformity as a conductive layer transition between the opening and the surface of the overlay mold. 19. The RF module of claim 18, wherein the conductive layer comprises a layer formed by a metallic coating. 20. A wireless device, comprising: Antenna; and A module for communicating with an antenna, configured to facilitate either or both the transmission and reception of RF signals via the antenna, the module comprising a package substrate configured to accommodate a plurality of components, the package substrate including a ground plane, the module further comprising a surface mount device (SMD) mounted on the package substrate, the SMD including an upward-facing metal layer and including an RF filter, the module further comprising an overlay formed on the package substrate, the overlay being sized to cover the SMD, the module further comprising an opening defined by the overlay in a region above the SMD, the opening having a depth sufficient to expose at least a portion of the metal layer, the module further comprising a conductive layer formed on the overlay, the conductive layer being configured to fill at least a portion of the opening to provide an electrical path between the conductive layer, the metal layer of the SMD and the ground plane.