阅读说明：本技术 相互屏蔽的印刷电路板组装件 (Mutually shielded printed circuit board assembly ) 是由 J·A·哈里根 于 2020-03-31 设计创作，主要内容包括：一种电子组装件,包括第一印刷电路板(PCB)、第二PCB和接地屏蔽。第一PCB包括第一多个电子组件和第一导电层。第二PCB包括第二多个电子组件和第二导电层。接地屏蔽被电连接在第一PCB的第一导电层与第二PCB的第二导电层之间以电连接第一PCB与第二PCB。第一PCB和第二PCB以堆叠方式被布置,使得该第一导电层和该第二导电层相互屏蔽第一多个电子组件中的至少一者和第二多个电子组件中的至少一者以防电磁干扰。(An electronic assembly includes a first Printed Circuit Board (PCB), a second PCB, and a ground shield. The first PCB includes a first plurality of electronic components and a first conductive layer. The second PCB includes a second plurality of electronic components and a second conductive layer. The ground shield is electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB to electrically connect the first PCB and the second PCB. The first PCB and the second PCB are arranged in a stacked manner such that the first conductive layer and the second conductive layer shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from each other against electromagnetic interference.)

1. An electronic assembly, comprising:

a first Printed Circuit Board (PCB) including a first plurality of electronic components and a first conductive layer;

a second PCB comprising a second plurality of electronic components and a second conductive layer; and

a ground shield electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB to electrically connect the first PCB and the second PCB, wherein the ground shield at least partially shields at least one of the first plurality of electronic components and/or at least one of the second plurality of electronic components, wherein the ground shield comprises at least one surface mountable electronic component electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB, and

wherein the first PCB and the second PCB are arranged in a stacked manner such that the first conductive layer and the second conductive layer shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from each other.

2. The electronic assembly of claim 1, wherein the at least one surface-mountable electronic component comprises a zero ohm resistor.

3. The electronic assembly of claim 1, wherein the at least one surface-mountable electronic component comprises a decoupling, filtering, or matching component.

4. The electronic assembly of claim 3, wherein the decoupling, filtering, or matching component is one of a shunt capacitor, an inductor, or a multi-element filter.

5. The electronic assembly of claim 1, wherein the at least one surface-mountable electronic component comprises a non-rigid or flexible surface-mountable electronic component.

6. The electronic assembly of claim 1, wherein at least one of the first plurality of electronic components and/or at least one of the second plurality of electronic components are thermally connected to an opposing PCB by mechanical contact or a thermal interface material.

7. The electronic assembly of claim 1, further comprising a third PCB including a third conductive layer, wherein at least one additional surface mountable electronic component is electrically connected between the first conductive layer of the first PCB and the third conductive layer of the third PCB such that the first conductive layer and the third conductive layer provide mutual shielding.

8. The electronic assembly of claim 1, wherein the ground shield comprises a metal sidewall or fence having at least one slot, wherein at least one surface mountable electronic component is positioned in the at least one slot, and wherein the surface mountable electronic component is electrically connected between the first PCB and the second PCB.

9. The electronic assembly of claim 1, wherein the ground shield extends along substantially an entire first perimeter of the first PCB and an entire second perimeter of the second PCB.

10. The electronic assembly of claim 1, further comprising one or more additional surface mountable electronic components electrically connected between the first PCB and the second PCB at any location within a mutually shielded region formed between the first PCB and the second PCB, wherein the one or more additional surface mountable electronic components serve as an interconnect between the first PCB and the second PCB.

11. The electronic assembly of claim 1, further comprising:

a non-shielded electrical connector electrically connected between a first electronic component of the first PCB and a second electronic component of the second PCB.

12. The electronic assembly of claim 1, wherein the ground shield is electrically connected to the first PCB via a high temperature solder, and the ground shield is electrically connected to the second PCB via a reflow solder, the reflow solder having a lower melting point than the high temperature solder.

13. A method for manufacturing an electronic assembly, the method comprising:

electrically and mechanically attaching one or more surface mountable electronic components to a Printed Circuit Board (PCB) comprising a first plurality of electronic components such that the one or more surface mountable electronic components form a perimeter on the first PCB at least partially around at least one of the first plurality of electronic components;

aligning the first PCB with a second PCB comprising a second plurality of electronic components such that the one or more surface-mountable electronic components form a perimeter on the second PCB at least partially around at least one of the second plurality of electronic components; and

electrically and mechanically attaching the one or more surface mountable electronic components to the second PCB when the first PCB and the second PCB are aligned such that the first PCB is electrically connected to the second PCB via the one or more surface mountable electronic components to encapsulate and electromagnetically isolate at least one of the first plurality of electronic components and at least one of the second plurality of electronic components.

14. The method of claim 13, wherein the one or more surface mountable electronic components are electrically connected and mechanically attached to the first PCB using a pick and place machine.

15. The method of claim 13, wherein the one or more surface mountable electronic components are electrically connected and mechanically attached to the first PCB via high temperature solder.

Background

Electromagnetic (EM) radiation may be emitted from various electron sources. Such EM radiation may prevent the electronic device from functioning properly due to electromagnetic interference (EMI). To prevent EMI, an EMI shield may be electrically connected to a Printed Circuit Board (PCB) to block EM radiation. One or more EMI shields may sometimes be required to cover the entire PCB or a portion of the PCB.

Disclosure of Invention

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not limited to implementations that solve any or all disadvantages noted in any part of this disclosure.

An electronic assembly includes a first Printed Circuit Board (PCB), a second PCB, and a ground shield. The first PCB includes a first plurality of electronic components and a first conductive layer. The second PCB includes a second plurality of electronic components and a second conductive layer. The ground shield is electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB to electrically connect the first PCB and the second PCB. The first PCB and the second PCB are arranged in a stacked manner such that the first conductive layer and the second conductive layer shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from each other against electromagnetic interference.

Brief Description of Drawings

Fig. 1A and 1B schematically illustrate an example electronic assembly including mutually shielded Printed Circuit Boards (PCBs) electrically connected to a common ground shield.

Fig. 2A and 2B schematically illustrate another example electronic assembly that includes a mutually shielded PCB electrically connected to a common ground shield that includes a plurality of surface-mountable electronic components and/or surface-mountable metallic structures positioned around an entire perimeter.

Fig. 3A and 3B schematically illustrate another example electronic assembly including mutually shielded PCBs electrically connected to a common ground shield including a plurality of ground contacts, the common ground shield including surface-mountable electronic components and surface-mountable metallic structures located around different portions of a perimeter and other ground structures or materials electrically connecting the two PCBs.

Fig. 4 schematically illustrates another example electronic assembly that includes a plurality of surface-mountable electronic components electrically connected between ground planes of two mutually shielded PCBs.

Fig. 5 schematically illustrates another example electronic assembly that includes a plurality of surface-mountable electronic components electrically connected between ground planes of two mutually shielded PCBs.

Fig. 6 schematically illustrates another example electronic assembly in which a PCB provides mutual shielding in cooperation with two additional PCBs electrically connected on the same side of the PCB.

Fig. 7 schematically illustrates another example electronic assembly in which a PCB provides mutual shielding in cooperation with two additional PCBs electrically connected on opposite sides of the PCB.

FIG. 8 is a flow diagram depicting aspects of an example method for producing an electronic assembly.

Detailed Description

Certain electronic components mounted on a Printed Circuit Board (PCB) may generate signal noise that may electromagnetically interfere with other nearby radio components, thereby degrading the performance of the radio components. This form of electromagnetic interference may be referred to as desensitization or "desensitization," in which a radio receiver is unable to receive radio signals that it may be able to receive without interference. For example, desensitization of radio components may be caused by nearby electronic components with noise signals of similar frequencies, which may overload the radio and thus fail to fully receive the desired signal. Other situations may occur in which sensitive electronic components on the PCB may be protected from noise generated by the environment or elsewhere on the device. Furthermore, the equipment may need to comply with electromagnetic compatibility (EMC) regulations, which respectively specify maximum and minimum noise that the equipment may emit, or be operable in the presence of, the maximum and minimum noise. To mitigate desensitization and/or other electromagnetic interference effects, at least some electronic components on the PCB may be encapsulated by some form of electromagnetic interference (EMI) shielding to electromagnetically isolate the electronic components. As one example, EMI shielding includes a metal housing that surrounds electronic components on a PCB. The EMI shield may be electrically connected to a ground plane of the PCB to provide EMI shielding for the electronic component.

In electronic assemblies that cooperatively use two or more PCBs, the two or more PCBs may be electrically connected to each other by one or more electrical connectors. In past solutions, there would be a single EMI shield or multiple EMI shields per PCB. The use of separate EMI shields for each PCB may result in an increase in the size of the PCB, which in turn may result in an increase in the length of the electrical connector electrically connected between the PCBs. In one example of a side-by-side arrangement of PCBs, the electrical connector may have to extend beyond the perimeter formed by the EMI shield in order to reach the electronic components (or another electrical connection point — e.g., ground plane, power plane) being shielded within the EMI shield. In this case, the distance between the edge of the PCB and the electronic component may be increased to allow the EMI shield to be located therebetween, which may be the reason for increasing the length of the electrical connector. In another example where the PCBs are arranged in a stacked manner, the height of the EMI shield may be greater than the height of any electronic components on the PCB. In this case, the height of the EMI shield may be a cause of increasing the length of the electrical connector.

In addition, various EMI problems may arise when interconnecting between two PCBs. High speed signals passing through the interconnect are typically shielded using more complex, more expensive connectors or using mechanical shielding of the package interconnect. The number of interconnects used may be limited by cost or EMI requirements. If a lower cost connector can be used without EMI issues, multiple connectors can be used in multiple locations, which would reduce design constraints and/or cost. In addition, the length and location of the electrical connectors may limit signal integrity and the speed of signals that may be transmitted between PCBs, as well as presenting PCB trace routing challenges. Attempts to add more electrical connectors to simplify trace routing may have a negative impact on EMI.

Accordingly, the present specification is directed to an electronic assembly that addresses the above-mentioned problems. The electronic assembly may include a first PCB, a second PCB, and a ground shield electrically connected between conductive layers (e.g., ground planes) of the first and second PCBs. The first PCB includes a first plurality of electronic components. The second PCB includes a second plurality of electronic components. The first PCB and the second PCB may be arranged in a stacked manner such that a first conductive layer (e.g., a ground plane) of the first PCB and a second conductive layer (e.g., a ground plane) of the second PCB cooperate with the ground shield to shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from each other to provide isolation from the interior shielded area to the exterior. Such isolation may include inhibiting noise caused by electronic components from exiting the interior shielded area, or may include preventing EMI from the environment from entering the interior shielded area.

In some examples, the ground shield may surround the entire perimeter of the two PCBs to provide perimeter EMI shielding to the first and second pluralities of electronic components. In some examples, the ground shield may extend at least partially around one or more electronic components to provide EMI shielding for the one or more components. In some examples, the ground shield may include a perimeter ground shield and additional ground shield elements inside the perimeter to shield or isolate different electronic components.

Such electronic assemblies may improve the size and cost issues of previous solutions described above. In particular, by replacing two separate EMI shields with a mutual shield provided by the conductive layers of two PCBs and a single common ground shield, the distance (i.e., height) between the two PCBs may be reduced. This in turn may reduce the length of the electrical connector electrically connected between the two PCBs. Further, in such electronic assemblies, electrical connectors may be electrically connected between the PCBs within the interior shielding region. This allows the use of less costly unshielded electrical connectors. Additionally, the electrical connector may be electrically connected between the PCBs at any location within the inner shielding region. This allows for layout design flexibility, which may increase the integration density of electronic components on the PCB, which may reduce the footprint of the PCB. Furthermore, such design flexibility allows for the use of additional electrical connections between PCBs as needed, because lower cost non-shielded electrical connectors may be used for such connections, and because not all traces/connections must be fed through a single shielded electrical connector.

In some implementations, the ground shield can include one or more surface mountable electronic components or surface mountable mechanical structures electrically connected between the first PCB and the second PCB. Such surface mountable electronic components or surface mountable mechanical structures may be configured to provide EMI shielding to at least some of the electronic components of the first and second PCBs. In some examples, such surface mountable electronic components or surface mountable mechanical structures may be commercialized electronic components having standardized sizes and shapes, which are configured to be mounted on a PCB in an automated manner using commercial machinery (e.g., pick and place machines). By using such a production method, the time and cost of producing such an electronic assembly can be reduced. Furthermore, in some cases, surface mountable electronic components may provide additional benefits in addition to EMI shielding. In some examples, the surface-mountable electronic components may include decoupling, filtering, or matching components that may be electrically connected between conductive traces of two PCBs. The decoupling, filtering or matching components may be used to shunt or filter signals or noise, filter or condition signals, or for impedance matching of signals transmitted via the conductive traces.

Fig. 1A and 1B schematically illustrate an example electronic assembly 100 that includes a first PCB 102 and a second PCB 104 electrically connected to a common ground shield 106. Fig. 1A shows the second PCB 104 spaced apart from the first PCB 102 to expose the ground shield 106 and a first plurality of electronic components 108 located on a surface 110 of the first PCB 102. In addition, a second plurality of electronic components 112 is located on a second surface 114 of second PCB 104. The first and second PCBs 102 and 104 are arranged in a stacked manner such that the surface 110 is opposite the surface 114.

Any suitable type of electronic component may be mounted on a surface of first PCB 102 or second PCB 104. Non-limiting examples of electronic components that may be mounted on the surfaces of the first and second PCBs 102, 104 include: passive circuit components (e.g., capacitors, resistors, inductors), active circuit components (e.g., diodes, transistors), electromechanical components, opto-electronic components, display components, audio components, sensor components, Radio Frequency (RF) components, Integrated Circuits (ICs), system on a chip (SoC), and power components. In some examples, at least some of the plurality of electronic components 108 and/or 112 may be commercially available surface-mountable or surface-mount technology (SMT) type components. In some examples, at least some of the plurality of electronic components 108 and/or 112 optionally may be through-hole type components.

A plurality of conductive traces 116 may extend along the surface 110 of the first PCB 102. The plurality of conductive traces 116 may be configured to electrically connect the plurality of electronic components 108 to various other electronic components and/or other circuitry (e.g., power, ground) on the first PCB 102. The plurality of conductive traces 116 may be formed from any suitable conductive material. As one example, the conductive traces 116 comprise copper. Any suitable number of conductive traces 116 may be disposed on surface 110 of first PCB 102 according to any suitable layout design. Further, in some examples, one or more of the conductive traces 116 may be connected to different non-surface layers of the first PCB 102. Similarly, the second PCB 104 may include a plurality of conductive traces (not shown). In some examples, the electronic assembly may include electrical connectors that are electrically connected between conductive traces on the first and second PCBs 102, 104.

Board-to-board interconnect 118 is mounted on surface 110 of first PCB 102. The interconnect 118 may be configured to make electrical connection with a corresponding interconnect (not shown) on the second PCB 104 to enable signals to be sent between the two PCBs. The interconnects 118 may take any suitable form and may be electrically and/or mechanically connected to corresponding interconnects on the second PCB 104 in any suitable manner. As a non-limiting example, the interconnect may be a snap fit, a spring fit, or a press fit with a corresponding interconnect to connect the two PCBs. In the depicted example, the interconnect 118 is located in the center of the first PCB 102. It should be understood that the interconnects may be placed in any suitable location on first PCB 102. In some examples, two or more interconnects may be electrically connected between the two PCBs 102, 104.

The first and second PCBs 102, 104 may take any suitable form. More specifically, the first and second PCBs 102, 104 may be sized and shaped to accommodate the plurality of electronic components 108, 112 and the plurality of conductive traces 116. The first and second PCBs 102, 104 may include any suitable number of different layers, including conductive layers (e.g., ground layers, power layers) and non-conductive/base layers (e.g., surface layers, insulating layers). In some examples, either of the first and second PCBs 102, 104 may be non-rigid or flexible.

Fig. 1B schematically shows the second PCB 104 electrically and mechanically attached (affix) to the first PCB 102 via a ground shield 106. The ground shield 106 may be electrically connected between a first conductive layer of the first PCB 102 and a second conductive layer of the second PCB 104. The first and second PCBs 102, 104 may be arranged such that conductive layers, e.g., ground planes (not shown) of the first and second PCBs 102, 104, provide mutual EMI shielding. In particular, the conductive layer in the first PCB 102 may provide a lower EMI shielding layer and the conductive layer in the second PCB 104 may provide a higher shielding layer. The lower shield layer of the first PCB 102, the upper shield layer of the second PCB 104, the surrounding ground shield 106 and the appropriate PCB vias collectively form an inner shield region that electromagnetically isolates the electronic components 108, 112 and traces 116 located therein. The ground shield 106 may serve a number of additional purposes, such as acting as a heat sink, a base, or a structural component that provides mechanical support.

The electronic assembly optionally may include features that facilitate heat dissipation from the electronic components. In some implementations, the ground shield may be porous or may have holes to allow air to flow in the space between the PCBs. In some implementations, the electronic component 108 or 112 may be thermally connected to the opposing PCB by mechanical contact or thermal interface material. The opposing PCB may have a plurality of vias or copper layers to spread or dissipate heat from the electronic components. In some implementations, multiple holes may be formed in the opposing PCB and multiple heat sinks may be attached directly to the electronic component 108 or 112. In some implementations, holes may be formed in the PCB to allow airflow through the PCB. In some implementations, the thermal potting material may fill the space between the PCBs. In some implementations, the ground shield may be a vapor chamber and may be configured to provide dual shielding and cooling functionality.

In some examples, the ground plane may extend substantially under the entire surface of the PCBs 102, 104. In some examples, the first and second PCBs 102, 104 may include partial or non-continuous layers that occupy only a portion of the total area of the PCB. In some such examples, the first and second PCBs 102, 104 may provide mutual shielding in portions of the two PCBs having overlapping ground planes.

In the depicted example, the ground shield 106 extends continuously around the perimeter of the first and second PCBs 102, 104 to provide EMI shielding for all electronic components 108, 112 and conductive traces 116 on the surface of the PCBs 102, 104. In some examples, the ground shield 106 may surround only some of the electronic components 108, 112 and/or the conductive traces 116 to form a shield sub-region between two conductive layers of the PCBs 102, 104. In some such examples, other electronic components not positioned within the shielded sub-area may be partially shielded or unshielded. In some implementations, the ground shield can include a perimeter ground shield and an additional internal ground element that at least partially surrounds the individual electronic component or group of electronic components to isolate the electronic component from other electronic components within the internal shield region. In other words, the ground shield may include a plurality of different inner shield regions that are isolated from each other to strategically prevent undesirable resonances or couplings within the structure and/or to provide additional grounding in some regions.

The ground shield 106 may include any suitable conductive material, such as metal, conductive foam, conductive fabric on foam, conductive elastomer, metal chassis or heat sink, surface mountable metal structure, any other suitable conductor, or combinations thereof. The metallic ground shield may be made in any suitable manner. For example, the metallic ground shield may be machined, stamped or drawn. In some examples, the ground shield 106 may include metallized plastic or resin. In some examples, the ground shield 106 may include an aluminum base. The ground shield 106 may be electrically and mechanically attached to the first and second PCBs 102, 104 in any suitable manner. As one example, the ground shield 106 may be electrically and mechanically attached to the first and second PCBs 102, 104 via metal clips connected to the ground plane of each of the PCBs 102, 104. The metal clip may hold the ground shield 106 in place via a tension fit or a spring force fit. As another example, the ground shield 106 may be electrically connected and mechanically attached to the first and second PCBs 102, 104 via solder. As discussed in further detail below, in some implementations, different types of solder optionally may be used to connect different components to facilitate construction of the electronic assembly 100.

In some examples, the electronic component on the PCB may be an EM radiation or coupling source, and the inner shielding region may be configured to encapsulate the electronic component to contain the EM radiation or coupling at the source. In other examples, electronic components on the PCB may be susceptible to EMI, and the inner shielding region may be configured to encapsulate the electronic components to prevent EM radiation or coupling from reaching the electronic components.

Note that the depicted electronic assembly includes only electronic components located on the inner surface of the PCB. It should be understood that additional electronic components may also optionally be positioned on the outer surface of the PCB. In some of these examples, there may be an internal ground plane layer inside the PCB with a via opening that allows some signals to pass between the outer and inner surfaces through the PCB. In some such examples, decoupling capacitors or other decoupling, filtering, or matching components may be placed at these locations on the PCB to shunt noise to the ground plane and prevent it from escaping the shielded area. In some examples, decoupling, filtering, or matching components may not be used at such locations if the application does not require high shielding efficiency.

Fig. 2A and 2B schematically illustrate another example electronic assembly 200 that includes a first PCB 202 and a second PCB204 electrically connected to a common ground shield 206, the common ground shield 206 including a plurality of commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 around the entire perimeter of the PCBs 202, 204. Fig. 2A shows the second PCB204 spaced apart from the first PCB 202 to expose the ground shield 206 and a first plurality of electronic components 208 located on a surface 210 of the first PCB 202. In addition, a second plurality of electronic components 212 is located on a second surface 214 of second PCB 204. A plurality of conductive traces 216 may extend along the surface 210 of the first PCB 202. The plurality of conductive traces 216 may be configured to electrically connect the plurality of electronic components 208 to various other electronic components and/or other circuitry (e.g., power, ground) on the first PCB 202. Similarly, the second PCB204 may include a plurality of conductive traces (not shown). The first and second PCBs 202 and 204 are arranged in a stacked manner such that the surface 210 is opposite the surface 214.

Fig. 2B schematically illustrates the second PCB204 being electrically and mechanically attached to the first PCB 202 via a plurality of commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 of the ground shield 206. The first and second PCBs 202, 204 may be arranged such that conductive layers, e.g., ground planes (not shown) of the first and second PCBs 202, 204, provide mutual EMI shielding. Further, the first and second PCBs 202, 204, in cooperation with the plurality of commercial surface-mountable electronic components and/or surface-mountable metallic structures 207 forming the ground shield 206, may collectively form an internal shield region that electromagnetically isolates the electronic components 208, 212 and traces 216 located therein. The ground shield 206 may serve a number of additional purposes, such as acting as a heat sink, a base, or a structural component that provides mechanical support.

In some implementations, the ground shield 206 can be used to dissipate heat using separate surface mountable electronic components and/or surface mountable metallic structures 207. Heat can be dissipated via heat conduction, convection, or radiation. A plurality of surface mountable electronic components and/or surface mountable metallic structures 207 may be added in the interior region between the PCBs to improve heat dissipation.

Each of the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may provide an electrical connection between the first conductive layer of the first PCB 202 and the second conductive layer of the second PCB204, such that the plurality of commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 collectively form the ground shield 206. In some examples, one or more of the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may include a zero-ohm resistor that provides an electrical connection between the PCBs 202, 204. In some examples, the commercialized surface-mountable electronic components and/or surface-mountable metallic structure 207 may include other electronic components as discussed in further detail herein.

Typically, commercial surface-mountable electronic components are mounted to a single PCB. In such cases, the commercialized surface-mountable electronic component is oriented "horizontally", with both ends electrically connected to different connection points on the same PCB. Instead, each of the plurality of commercially available surface mountable electronic components and/or surface mountable metallic structures 207 included in the ground shield 206 is oriented "vertically" at the ends and connected between different PCBs.

The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may have standardized sizes and dimensions. Such commercially available surface-mountable electronic components may be of any suitable size and/or packaging type (e.g., 0402 or 0201). By using commercially available surface mountable components in this manner, the ground shield 206 may have a substantially uniform height and thickness. Further, the electronic assembly 200 may be constructed using commercial manufacturing equipment, such as a pick and place machine, to electrically connect the commercialized surface-mountable electronic component or surface-mountable metallic structure 207 to the PCB. In other words, by using commercial manufacturing equipment, the production cost of the electronic assembly 200 may be reduced because the electrical and mechanical characteristics of the components have been designed, tested, and mass produced.

Note that commercial surface-mountable electronic components and/or surface-mountable metallic structures are one example of the types of electronic components that may be used to form the ground shield 206, and other types of electronic components may be used in other examples. In addition, other assembly approaches/techniques may be used to produce such electronic assemblies.

The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may be electrically connected and/or mechanically attached between the first PCB 302 and the second PCB204 using any suitable electrically conductive material/technology. In one example, a commercial surface mountable electronic component and/or surface mountable metallic structure 207 may be soldered between the first PCB 202 and the PCB 204. In one particular example, the commercialized surface-mountable electronic component and/or surface-mountable metallic structure 207 may first be connected to the first PCB 202 via high-temperature solder soldering. The commercialized surface-mountable electronic component and/or surface-mountable metallic structure 207 may then be soldered to the second PCB204 via a reflowed solder having a melting point lower than the high temperature solder. This may allow the entire first PCB 202 and the mounted commercial surface mountable electronic components and/or surface mountable metallic structures 207 forming the ground shield 206 to be reflowed in an oven to be soldered to the second PCB204 without the need for high temperature solder melting.

Additionally or alternatively, in some examples, the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may be electrically connected and/or mechanically attached in different ways. Examples of such may include epoxy, solder, friction or mechanical fit, spring force, and adhesive.

In some implementations, at least some of the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 forming the ground shield 206 may be electrically connected to other conductors on either surface of the PCBs 202, 204 instead of the ground plane. As one example, commercial surface-mountable electronic components and/or surface-mountable metallic structures may be electrically connected between the power planes of the PCBs 202, 204. As another example, commercial surface-mountable electronic components and/or surface-mountable metallic structures may be electrically connected between conductive traces on the surface of the PCBs 202, 204. As yet another example, the commercialized surface-mountable electronic components and/or surface-mountable metallic structures may be electrically connected between another conductor (e.g., any copper sheet) exposed on the surface of the PCBs 202, 204.

It should be noted that when a commercial surface-mountable electronic component and/or surface-mountable metallic structure is electrically connected between conductive traces on the surface of the PCB 202, 204, it can serve as a low-cost interconnect. This differs from existing implementations in important respects. First, the interconnect is very low cost, for example, if a zero ohm resistor is used, the cost may be only a fraction of a penny. Second, it takes up little PCB board space because it requires only small footprint surface mount components. Third, any radiated or coupled EM noise is contained between the PCBs, and does not generate EMI extending to the outside of the PCBs, achieving a shielding effect of mutual PCB shielding. Fourth, it allows a large number of interconnects to be placed anywhere on the PCB, which allows for more flexible routing options, potentially requiring fewer PCB layers and a lower cost PCB, as well as enabling a high density design so that more data can be transferred from one PCB to another and/or more integrated circuits to be more tightly integrated together, due to the first three benefits. These are potential advantages over existing non-mutually shielded PCBs that are not connected together by commercially available surface-mountable electronic components and/or surface-mountable metallic structures.

Active electronic components (e.g., transistors, ICs) 208, 212 on the first or second PCBs 202, 204 may operate at high frequencies or fast clock signals, which may generate noise harmonics or broadband noise spectra. Under certain conditions (such as impedance mismatch, proximity, or geometry of conductors), electric and magnetic fields may radiate to space or couple to other electronic components. Further, the electronic components 208, 212 may be connected to a power source through conductive traces and/or other conductors having finite resistance and inductance. If the current drawn by the active electronic components changes, the voltage drop from the power supply to the device also changes due to these impedances. If multiple active devices share a common path to the power supply, changes in current drawn by one component may produce voltage changes large enough to affect the operation of other components, such as voltage spikes or ground bounce, so that state change components of one electronic component may couple to other electronic components through the common impedance of the power supply in the form of signal noise. In some cases, the electronic components may not generate noise, but the impedance matching with the electronic components needs to be optimized so that signal loss can be minimized. In other cases, noise may not be present, but filtering or conditioning of the signal may be required, such as a band pass filter, low pass filter, or duplexer.

To address these issues, in some implementations, one or more of the commercially available surface-mountable electronic components 207 may be decoupling, filtering, or matching components. In some examples, decoupling, filtering, or matching components may be electrically connected between conductive traces on each PCB 202, 204. Decoupling, filtering or matching components connected between the conductive traces may help prevent the radiation or coupling of electromagnetic interference due to component frequency content or rapidly changing supply currents. In particular, the decoupling, filtering, or matching component may provide a bypass path for the transient current to flow through the return path rather than allowing the transient current to flow through the common impedance of the conductive traces. In this case, the decoupling, filtering, or matching components may serve a dual role configured to filter or match signals or shunt noise from the conductive traces and provide an electrical and mechanical connection between the first PCB 202 and the second PCB 204. Furthermore, the electrical connection provided by the decoupling, filtering, or matching components may help form an internal shielding region between the PCBs 202, 204. In some examples, the decoupling, filtering, or matching components may be electrically connected between other conductors of the PCBs 202, 204, including the power plane and the ground plane.

In some cases, the decoupling, filtering, or matching component may be configured to act as a filter. As one example, the decoupling, filtering, or matching component may be configured to act as a low pass filter. Such decoupling, filtering, or matching components may be configured to filter any suitable frequency range. In some examples, different decoupling, filtering, or matching components may be configured to filter different frequency ranges depending on the type of connection (e.g., to trace, ground plane, power plane) and/or other factors. Further, the decoupling, filtering, or matching components may be configured to match the impedance of the traces, as applicable. In some cases, the decoupling, filtering, or matching components may be configured to act as a ground reference for the electronic components, while the shielding may be considered a secondary function. In some cases, decoupling, filtering, or matching components may be used as DC blocks.

Any suitable type of decoupling, filtering, or matching component may be integrated into the ground shield 206 and electrically connected between the PCBs 202, 204. For example, the decoupling, filtering, or matching components may include a decoupling capacitor, an inductor, a multi-element filter (e.g., an "L," "T," "pi" topology), or another type of filter or signal conditioning component, such as a duplexer, circulator, combiner, or the like.

The ground shield 206 may include any suitable combination of different types of commercially available surface mountable electronic components and/or surface mountable metallic structures 207. In some examples, all of the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 207 may be the same type of electronic component (e.g., a zero ohm resistor). In some examples, different types of electronic components may be positioned according to the surface layout of the PCBs 202, 204. For example, a zero ohm resistor may be electrically connected between the perimeter ground planes of the PCBs 204, 204 at one portion of the ground shield 206, and a decoupling, filtering, or matching component may be electrically connected between the conductive traces of the PCBs 202, 204 at another portion of the ground shield 206. Any suitable type of commercially available surface-mountable electronic component and/or surface-mountable metallic structure may be positioned at any suitable portion of the ground shield 206 depending on the type of connection and functionality required for the electronic component.

Fig. 3A and 3B schematically illustrate another example electronic assembly 300 that includes a first PCB 302 and a second PCB 306 electrically connected to a common ground shield 304, the common ground shield 306 including a plurality of commercially available surface-mountable electronic components and/or surface-mountable metallic structures 307 and/or other conductive materials 309. Fig. 3A shows the second PCB 304 spaced apart from the first PCB 302 to expose the ground shield 306 and a first plurality of electronic components 308 located on a surface 310 of the first PCB 302. In addition, a second plurality of electronic components 312 is located on a second surface 314 of second PCB 304. A plurality of conductive traces 316 may extend along the surface 310 of the first PCB 302. The plurality of conductive traces 316 may be configured to electrically connect the plurality of electronic components 308 to various other electronic components and/or other circuitry (e.g., power, ground) on the first PCB 302. Similarly, second PCB 304 may include a plurality of conductive traces (not shown). The first and second PCBs 302 and 304 are arranged in a stacked manner such that the surface 310 is opposite the surface 314.

The ground shield 306 may include a plurality of commercially available surface-mountable electronic components and/or surface-mountable metallic structures 307 that may be intelligently positioned around the perimeter to provide particular functionality between particular connections. For example, decoupling, filtering, or matching components may be positioned around the perimeter to align with and electrically connect between conductive traces of the PCBs 302, 304. As another example, commercial surface-mountable electronic components and/or surface-mountable metallic structures may be positioned around the perimeter to align with and electrically connect between power planes of the PCBs 302, 304. Another example is if the conductive material 309 is a heat sink, a base or structural mechanical component and a plurality of commercially available surface mountable electronic components and/or surface mountable metallic structures 307 are used to fill any remaining gaps or voids. Another example is if the conductive material 309 requires a large relief area, for example if it is a conductive foam, and a plurality of commercial surface mountable electronic components or surface mountable metallic structures 307 are placed in areas where there is insufficient space to accommodate the relief area. In another example, the conductive material 309 forms a perimeter and the plurality of commercialized surface-mountable electronic components or surface-mountable metallic structures 307 form an additional ground shielding element inside the perimeter. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 307 may be intelligently positioned at any portion of the ground shield 306 to provide any suitable functionality.

Further, other electrically-conductive material 309 may be connected between the ground planes of the PCBs 302, 304 in a portion of the perimeter (which portion of the perimeter may include a portion within the perimeter where no commercial surface-mountable electronic components 307 are present) so as to provide EMI shielding around substantially the entire perimeter, which may include portions inside the perimeter of the PCBs 302, 304. In some examples, the other conductive material 309 may provide structural rigidity to ensure that the two PCBs 302, 304 remain parallel and/or separated. In some examples, the other conductive material 309 may be non-rigid or flexible. In some such examples, the PCB and/or surface mountable electronic component may also be non-rigid or flexible. Other conductive materials 309 may include any suitable type of conductive material, including stamped or drawn metal, conductive foam, conductive elastomer, conductive fabric on foam, conductive non-woven, cast or machined aluminum, or other conductive material. The other conductive material 309 may be electrically connected to the ground plane of the PCBs 302, 304 in any suitable manner. Such examples may include epoxy, welding, friction or mechanical fit (e.g., via metal clips), spring force, and adhesives. There may be multiple layers of different conductive materials, for example one such stacked layer is a conductive adhesive, a conductive foam, a conductive adhesive. Many other combinations are possible.

The plurality of commercially available surface-mountable electronic components and/or surface-mountable metallic structures 307 may be integrated with the other conductive material 309 in the ground shield 306 in any suitable manner. In the depicted example, the other conductive material 309 forms a sidewall or perimeter fence having a cutout or slot 318, the cutout or slot 318 configured to receive a commercial surface mountable electronic component and/or surface mountable metallic structure 307. The slot(s) 318 may be sized to minimize the distance between the other conductive material 309 and the commercial surface mountable electronic component and/or surface mountable metallic structure 307 in order to maintain the shielding effectiveness of the ground shield 306 and reduce parasitic inductance. In other words, the commercialized surface-mountable electronic component and/or surface-mountable metallic structure 307 may substantially fill the space of the slot to maintain shielding along the sidewalls and reduce parasitic inductance. In another example, the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 307 may be confined within the multi-layer sidewalls of the ground shield 306.

The electronic assembly 300 may include an interior wall or compartment. For example, an interior shielded compartment 320 may be formed around the integrated circuit 322 to isolate the integrated circuit from other electronic components on the first PCB 302. Commercial surface mountable electronic components and/or surface mountable metallic structures 307 may occupy slots in these interior compartment walls in the same manner as the external ground shield 306 to provide the same function. For example, the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 324 may be electrically connected to conductive traces that connect between the integrated circuit 322 and an adjacent integrated circuit located outside the inner shielded compartment 322. In one example, the commercialized surface-mountable electronic component and/or surface-mountable metallic structure 324 may provide the decoupling, filtering, or matching functions of the conductive traces.

Fig. 3B schematically illustrates the second PCB 304 being electrically and mechanically attached to the first PCB 302 via a plurality of commercialized surface-mountable electronic components and/or surface-mountable metallic structures 307 and other electrically conductive material 309 of the ground shield 306. The first and second PCBs 302, 304 may be arranged such that conductive layers, e.g., ground planes (not shown) of the first and second PCBs 302, 304, provide mutual EMI shielding. Further, the first and second PCBs 302, 304 in cooperation with the plurality of commercial surface-mountable electronic components and/or surface-mountable metallic structures 307 and other conductive materials 309 forming the ground shield 306 may collectively form an inner shield region that electromagnetically isolates the electronic components 308, 312 and traces 316 located therein.

Fig. 4 and 5 show aspects of different example electronic assemblies with a common ground shield electrically connected between two mutually shielded PCBs. In particular, these figures show partial cross-sectional views of electronic assemblies.

Fig. 4 illustrates an example electronic assembly 400. The depicted view is a partial cross-section taken at the angle of line a-a in fig. 2A. However, line a-a is provided only as a frame of reference because electronic assembly 400 differs from electronic assembly 200 shown in fig. 2A. The electronic assembly 400 includes a first PCB402 that includes a plurality of base layers 404 (e.g., a first layer 404A, a second layer 404B, a third layer 404C). The ground plane 406 is located between the first layer 404A and the second layer 404B. Power plane 408 is located between second layer 404B and third layer 404C. Outer conductive layer 410 is located below third layer 404C.

The electronic assembly 400 includes a second PCB 412 opposite the first PCB 402. The second PCB 412 includes a plurality of base layers 414 (e.g., a first layer 414A, a second layer 414B, a third layer 414C). The ground plane 416 is located between the first layer 414A and the second layer 414B. The power plane 418 is located between the second layer 414B and the third layer 414C. The outer conductive layer 420 is located over the third layer 414C.

In the depicted example, the plurality of commercially available surface mountable electronic components and/or surface mountable metallic structures 422 collectively form a ground shield that is electrically connected between the first PCB402 and the second PCB 412. Within the ground shield, different commercially available surface mountable electronic components 422 may have different types of connections and provide different functions. In particular, the commercialized surface-mountable electronic components and/or surface-mountable metallic structures 422A, 422B, 422G and 422H are all electrically connected between the ground planes 406 and 416. For example, these components may be zero ohm resistors. Commercial surface-mountable electronic components and/or surface-mountable metallic structures 422D are electrically connected between power planes 408 and 418. The commercially available surface-mountable electronic components 422B, 422C, 422E and 422F are decoupling, filtering or matching components that are electrically connected between different conductive traces on the surfaces of the first and second PCBs 402, 412. In some implementations, additional decoupling, filtering, or matching components may reside entirely on one PCB and be connected to any of the decoupling, filtering, or matching components 422B, 422C, 422E, 422F. These additional decoupling, filtering, or matching components may be used to provide performance gains and/or additional functionality for filtering or matching applications. For example, a multi-pole lumped element filter may be constructed. Such different electrical connections and functionality provided by the different commercially available surface-mountable electronic components 422 may allow for design flexibility in that the PCBs may be electrically connected to each other via any suitable exposed conductor (e.g., copper) on the surface of the PCB.

Note that outer conductive layers 410 and 420 may optionally be added to electronic assembly 400 to provide additional EMI shielding. In such cases, through holes are added to complete the shielding shell.

Fig. 5 illustrates an example electronic assembly 500. The depicted view is a partial cross-section taken from the angle of line B-B in fig. 2A. However, line B-B is provided only as a frame of reference because electronic assembly 500 differs from electronic assembly 200 shown in fig. 2A. The electronic assembly 500 includes a first PCB 502 including a first ground plane 508 and a second PCB 504 including a second ground plane 510. The first PCB 502 is opposite the second PCB 504 in the stack so that the ground planes 508 and 510 provide mutual EMI shielding. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 506A and 506B are electrically connected between the ground planes 508 and 510 of the first and second PCBs 502 and 504 as ground shields that cooperate with the mutually shielded PCBs 502 and 504 to form a portion of the inner shield region 512.

The use of commercially available surface-mountable electronic components and/or surface-mountable metallic structures to form a ground shield may reduce the height (Z) of the inner shield region 512 relative to an assembly in which each PCB is individually shielded via a "can" type EMI shield. Such a reduced height may reduce the overall form factor of the electronic assembly 500. However, due to the limited height of the inner shielded region 512, different electronic assemblies may be intelligently disposed on the surfaces of the two PCBs 502, 504 so that the electronic components do not contact or otherwise interfere with each other. For example, a capacitor 514 having a greater height requirement may be positioned on the first PCB 502 such that no electronic components on the second PCB 504 are opposite the capacitor 514. As another example, a surface mount component 516 having a smaller height requirement may be positioned on the first PCB 502 and an integrated circuit 518 also having a smaller height requirement may be positioned on the second PCB 504 opposite the surface mount component 516, as the two electronic components do not contact or otherwise mechanically interfere with each other.

The inner shielded region 512 may allow for electrical connection between the first PCB 502 and the second PCB 504 using a non-shielded electrical connector 520. The unshielded electrical connector 520 may be electrically connected between any suitable electronic components, traces, and other connection points on the PCBs 502, 504. The non-shielded electrical connector 520 need not have any EMI shielding material or need only have a small amount of EMI shielding material because the electrical connector 520 resides in the inner shielded region 512. The lack of EMI shielding material may reduce the cost of the electrical connector 520. In some examples, if lower speeds or more current are desired, the electrical connector 520 is comprised of a plurality of commercially available surface mountable electronic components and/or surface mountable metallic structures. The electrical connector 520 may also be an integrated structure to support high speed or other requirements.

The inner shielded region 512 may allow design flexibility of the electronic assembly 500, as different electrical connections between the PCBs 502, 504 may be placed at any location within the inner shielded region 512. For example, unshielded electrical connector 520 may be positioned at any suitable location within inner shielded region 512. As another example, commercial surface-mountable electronic components and/or surface-mountable metallic structures 522 may be connected between ground planes 508 and 510 to provide a ground reference at any suitable location within inner shield region 512. In some implementations, multiple commercial surface-mountable electronic components and/or surface-mountable metallic structures placed inside in a similar manner as the commercial surface-mountable electronic components or surface-mountable metallic structures 522 may be used to create mutually isolated internal shielded cavities. Additionally or alternatively, one or more commercially available surface mountable electronic components are electrically connected between the PCBs 502, 504 at any location to serve as an interconnect. In general, the inner shield area 512 provides flexibility for various electronic components to be disposed on the surface of the PCBs 502, 504 according to any suitable layout design depending on the purpose of the electronic assembly 500.

Fig. 6 schematically illustrates another example electronic assembly 600 in which a first PCB 602 cooperates with a second PCB 604 and a third PCB 606 to provide mutual shielding, both second PCB 604 and third PCB 606 being electrically connected on the same side/surface 608 of first PCB 602. The first PCB 602 includes a first ground plane 610. The second PCB includes a second ground plane 612. The third PCB comprises a third ground plane 614. The first PCB 602 is opposite the second PCB 604 in the stack such that the first and second ground planes 610 and 612 provide mutual EMI shielding. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 616A and 616B are electrically connected between the first and second ground planes 610 and 612 of the first PCB 602 and the second PCB 604, as ground shields that cooperate with the mutually shielded PCBs 602 and 604 to form part of an inner shield area that isolates electronic components 618 (which may be, for example, integrated circuits).

Similarly, the first PCB 602 is opposite the third PCB 606 in the stack such that the first and third ground planes 610 and 614 provide mutual EMI shielding. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 616C and 616D are electrically connected between the first and third ground planes 610 and 614 of the first PCB 602 and the third PCB 606 as a ground shield cooperating with the mutually shielded PCBs 602 and 606 to form part of an inner shielding area of the isolated electronic component 612 (which may be a capacitor). In the depicted example, electronic components 618 and 620 may be isolated from each other in different, mutually shielded interior regions. In some examples, additional electronic components may be mounted to either the second PCB 604 or the third PCB 606 within a separate inner shielding region.

In the depicted scenario, a larger first PCB cooperates with smaller second and third PCBs attached to the first PCB to provide mutual shielding.

Fig. 7 schematically illustrates another example electronic assembly 700 in which a first PCB 702 provides mutual shielding in cooperation with a second PCB 704 and a third PCB 706, both of which are electrically connected on opposite sides/surfaces of the first PCB 702. In particular, the second PCB 704 is electrically connected to a first side 708 of the first PCB 702. The third PCB 706 is electrically connected to a second side 710 opposite the first side 708. The first PCB 702 includes a first ground plane 712. The second PCB includes a second ground plane 714. The third PCB includes a third ground plane 716. The first PCB 702 is opposite the second PCB 704 in the stack such that the first and second ground planes 712 and 714 provide mutual EMI shielding. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 718A and 718B are electrically connected between the first and second ground planes 712 and 714 of the first PCB 702 and the second PCB 704 as ground shields that cooperate with the mutually shielded PCBs 702 and 704 to form part of an inner shield area that isolates the electronic components 720 (which may be, for example, integrated circuits).

Similarly, the first PCB 702 is opposite the third PCB 706 in the stack such that the first and third ground planes 712 and 716 provide mutual EMI shielding. The commercialized surface-mountable electronic components and/or surface-mountable metallic structures 718C and 718D are electrically connected between the first and third ground planes 712 and 716 of the first PCB 702 and the third PCB 706 as ground shields that cooperate with the mutually shielded PCBs 702 and 706 to form part of an inner shield area that isolates electronic components 722 (which may be, for example, integrated circuits). In the depicted example, electronic components 720 and 722 may be isolated from each other in different, mutually shielded interior regions. In some examples, additional electronic components may be mounted to any of first PCB 702, second PCB 704, or third PCB 706 within a separate inner shield region.

In the depicted example, multiple PCBs are stacked such that each PCB shields adjacent PCBs from each other. In some implementations, a larger PCB may have multiple smaller, mutually shielded PCBs on its top and bottom surfaces.

It should be appreciated that the PCBs may cooperate with any suitable number of additional PCBs to provide mutual shielding. Furthermore, the multiple PCBs may have any suitable spatial arrangement relative to one another so as to provide such mutual shielding. In some implementations, multiple PCBs may be formed into geometric shapes such that the PCBs are shielded from each other. For example, six PCBs may form each face of a cube, with an interior shielding region. In such a case, the edges of the PCB would be mechanically and electrically connected. In this case, commercial surface-mountable electronic components or surface-mountable metallic structures may not be suitable for providing electrical connections between PCBs, as the PCBs may not be parallel to each other.

Fig. 8 illustrates aspects of an example method 800 for producing an electronic assembly as described herein. At 802, method 800 includes electrically and mechanically attaching one or more surface mountable electronic components, surface mountable metallic structures, and/or other conductors to a Printed Circuit Board (PCB) that includes a first plurality of electronic components. One or more surface mountable electronic components, surface mountable metallic structures, and/or other conductors may form a perimeter at least partially around at least one of the first plurality of electronic components on the first PCB. For example, one or more surface-mountable electronic components, surface-mountable metallic structures, and/or other conductors may be electrically and mechanically attached to a ground plane, power plane, or conductive trace of the first PCB.

In some examples, the plurality of surface-mountable electronic components, surface-mountable metallic structures, or other conductors may surround an integrally formed perimeter of the first plurality of electronic components on the first PCB. In some examples, a plurality of surface-mountable electronic components, surface-mountable metallic structures, or other conductors may form a perimeter around a single electronic component or group of electronic components on the first PCB. In some examples, a plurality of commercially available surface-mountable electronic components, surface-mountable metallic structures, or other conductors may form a perimeter around the first PCB and an internal additional internal shielding region around one or more electronic components of the first PCB.

In some examples, the ground shield may be formed by electrical and mechanical attachment to the first PCB using only a plurality of surface mountable electronic components. In some examples, a plurality of surface-mountable electronic components, surface-mountable metallic structures, and other conductors (e.g., stamped or drawn metal, conductive foam, metallized plastic, or resin) may cooperate to form a ground shield by being electrically and mechanically attached to the first PCB.

In some implementations, the method 800 may optionally include placing high temperature solder (or other connecting material, such as conductive epoxy) on the first PCB, vertically placing one or more of the commercialized surface-mountable electronic components using a pick-and-place machine such that one end contacts the high temperature solder (or other connecting material), and reflowing the first PCB and the one or more commercialized surface-mountable electronic components and/or surface-mountable metallic structures in an oven to electrically connect and mechanically attaching the one or more commercialized surface-mountable electronic components and/or surface-mountable metallic structures to the first PCB. In some implementations, the one or more commercialized surface-mountable electronic components and/or surface-mountable metallic structures may be electrically connected and mechanically attached to the first PCB via at least one of mechanical crimping, spring force, conductive epoxy, or soldering.

At 804, the method 800 includes aligning the first PCB with a second PCB including a second plurality of electronic components such that the one or more surface mountable electronic components form a perimeter on the second PCB at least partially around at least one of the second plurality of electronic components. In some implementations, the method steps may optionally be performed by a pick and place machine.

At 806, the method 800 includes electrically and mechanically attaching one or more surface mountable electronic components, surface mountable metallic structures, or other conductors to the second PCB when the first PCB and the second PCB are aligned such that the first PCB is electrically connected to the second PCB via the one or more surface mountable electronic components, surface mountable metallic structures, or other conductors to encapsulate and electromagnetically isolate at least one of the first plurality of electronic components and at least one of the second plurality of electronic components. For example, one or more surface-mountable electronic components, surface-mountable metallic structures, or other conductors may be electrically and mechanically attached to a ground plane, power plane, or conductive trace of the second PCB.

In some implementations, one or more of the commercialized surface-mountable electronic components and/or surface-mountable metallic structures may be first soldered to the first PCB via a high-temperature solder. One or more of the commercial surface mountable electronic components and/or surface mountable metallic structures may then be soldered to the second PCB via a reflow solder having a melting point lower than the high temperature solder. This may allow the entire first PCB and connected commercial surface mountable electronic components and/or surface mountable metallic structures to be reflowed in an oven to be soldered to the second PCB without the need for high temperature solder melting.

In some implementations, multiple additional smaller PCBs may be added to either side of the first larger PCB following the same process. In some implementations, three or more PCBs may be stacked using the same process.

The resulting electronic assembly enables the PCB to provide mutual EMI shielding in cooperation with one or more surface-mountable electronic components, surface-mountable metallic structures, or other conductors to encapsulate and electromagnetically isolate at least one of the first plurality of electronic components on the first PCB and at least one of the second plurality of electronic components on the second PCB. In some examples, more than two PCBs are used to form more complex mutual shielding assemblies.

In one example, an electronic assembly, comprising: a first Printed Circuit Board (PCB) including a first plurality of electronic components and a first conductive layer; a second PCB comprising a second plurality of electronic components and a second conductive layer; and a ground shield electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB to electrically connect the first PCB and the second PCB, wherein the ground shield at least partially shields at least one of the first plurality of electronic components and/or at least one of the second plurality of electronic components, wherein the ground shield comprises at least one surface mountable electronic component electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB, and wherein the first PCB and the second PCB are arranged in a stacked manner such that the first conductive layer and the second conductive layer mutually shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from electromagnetic interference. In this and/or other examples, the at least one surface-mountable electronic component may include a zero ohm resistor. In this and/or other examples, the at least one surface-mountable electronic component may include a decoupling, filtering, or matching component. In this and/or other examples, the decoupling, filtering, or matching component may be one of a shunt capacitor, an inductor, or a multi-element filter. In this and/or other examples, the at least one surface-mountable electronic component may include a non-rigid or flexible surface-mountable electronic component. In this and/or other examples, at least one of the first plurality of electronic components and/or at least one of the second plurality of electronic components may be thermally connected to an opposing PCB by mechanical contact or thermal interface material. In this and/or other examples, the electronic assembly may further include a third PCB including a third conductive layer, and the at least one additional surface mountable electronic component may be electrically connected between the first conductive layer of the first PCB and the third conductive layer of the third PCB such that the first conductive layer and the third conductive layer provide mutual shielding. In this and/or other examples, the ground shield may include a metal sidewall or rail having at least one slot, the at least one surface mountable electronic component is positioned in the at least one slot, and the surface mountable electronic component may be electrically connected between the first PCB and the second PCB. In this and/or other examples, the ground shield may extend along substantially an entire first perimeter of the first PCB and an entire second perimeter of the second PCB. In this and/or other examples, the electronic assembly may further include one or more additional surface mountable electronic components electrically connected between the first PCB and the second PCB at any location within the mutual shielding region formed between the first PCB and the second PCB, the one or more additional surface mountable electronic components operable as an interconnect between the first PCB and the second PCB. In this and/or other examples, the electronic assembly may further include a non-shielded electrical connector electrically connected between the first electronic component of the first PCB and the second electronic component of the second PCB. In this and/or other examples, the ground shield may be electrically connected to the first PCB via a high temperature solder, and the ground shield may be electrically connected to the second PCB via a reflow solder, the reflow solder having a melting point lower than the high temperature solder.

In one example, a method for manufacturing an electronic assembly, the method comprising: electrically and mechanically attaching one or more surface mountable electronic components to a Printed Circuit Board (PCB) comprising a first plurality of electronic components such that the one or more surface mountable electronic components form a perimeter at least partially around at least one of the first plurality of electronic components on the first PCB;

aligning the first PCB with a second PCB comprising a second plurality of electronic components such that one or more surface mountable electronic components form a perimeter on the second PCB at least partially around at least one of the second plurality of electronic components; and electrically and mechanically attaching the one or more surface mountable electronic components to the second PCB when the first PCB and the second PCB are aligned such that the first PCB is electrically connected to the second PCB via the one or more surface mountable electronic components to encapsulate and electromagnetically isolate at least one of the first plurality of electronic components and at least one of the second plurality of electronic components. In this and/or other examples, the one or more surface mountable electronic components may be electrically connected and mechanically attached to the first PCB using a pick and place machine. In this and/or other examples, the one or more surface mountable electronic components may be electrically connected and mechanically attached to the first PCB via a high temperature solder. In this and/or other examples, the one or more surface mountable electronic components may be electrically and mechanically attached to the second PCB via a reflow solder, the reflow solder having a melting point lower than the high temperature solder. In this and/or other examples, the one or more surface mountable electronic components may be electrically connected and mechanically attached to the first PCB and the second PCB via a conductive epoxy. In this example and/or other examples, the one or more surface mountable electronic components may be electrically connected and mechanically attached to the first PCB and the second PCB via one of mechanical crimping, spring force, or soldering.

In one example, an electronic assembly, comprising: a first Printed Circuit Board (PCB) including a first plurality of electronic components and a first conductive layer; a second PCB comprising a second plurality of electronic components and a second conductive layer; and a ground shield electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB to electrically connect the first PCB and the second PCB, wherein the ground shield is electrically connected to the first PCB via a high temperature solder, wherein the ground shield is electrically connected to the second PCB via a reflow solder, the reflow solder having a lower melting point than the high temperature solder; and wherein the first PCB and the second PCB are arranged in a stacked manner such that the first conductive layer and the second conductive layer shield at least one of the first plurality of electronic components and at least one of the second plurality of electronic components from each other to prevent electromagnetic interference. In this and/or other examples, the ground shield may include a plurality of surface mountable electronic components electrically connected between the first conductive layer of the first PCB and the second conductive layer of the second PCB, the plurality of surface mountable electronic components being positionable around substantially an entirety of the first perimeter of the first PCB and the second perimeter of the second PCB to electrically connect the first PCB with the second PCB.

It is to be understood that the configurations and/or approaches described herein are exemplary in nature, and that these specific embodiments or examples are not to be considered in a limiting sense, because numerous variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. As such, various acts illustrated and/or described may be performed in the sequence illustrated and/or described, in other sequences, in parallel, or omitted. Also, the order of the processes described above may be changed.

The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various processes, systems and configurations, and other features, functions, acts, and/or properties disclosed herein, as well as any and all equivalents thereof.