The following description relates to electronic devices. In particular, the following description relates to shields used to protect circuitry from electromagnetic interference and other noises, as well as provide a thermal dissipation path for heat generated by the circuitry. The shields described herein are formed by non-rigid materials, which enhance the compliant properties of the shields.
Shields can be used to block noise from interfering with circuitry. Some noise shields include a relatively rigid metal, such as sheet metal. However, while metal provides noise-blocking and thermal conductivity properties, the rigidity of metal layers (including sheet metal and other rigid metals) can cause certain issues. For example, in order to secure a shield to a circuit board, several holes are formed in the shield (including the metal layer), with each hole receiving a fastener. These holes define voids in the metal layer(s), which can permit noise to pass through the shield and extend to one or more components located on the circuit board.
Additionally, when the metal layer is secured to another structure located on the circuit board, other issues may occur. For example, when the fastener secures the shield to the circuit board, the fastener provides a force to the metal layer(s). When a (vertical) height difference exists between the fastener and the other structure, the metal layer(s) applies a bending moment to the structure. The force provided by the bending moment can cause the structure to bend or warp, and possibly break away from the circuit board, thereby reducing the noise mitigation capabilities of the shield. In order to offset the height differences, one or more heat-dissipating layers of the shield can be removed. However, with fewer heat-dissipating layers, the shield can no longer dissipate thermal energy as efficiently.
In one aspect, an electronic device is described. The electronic device may include a circuit board that carries a processing circuit. The electronic device may further include a shield that covers the processing circuit. The shield may include an electrically conductive layer configured to block radio interference generated by the processing circuit. The shield may further include a thermal assembly coupled with the electrically conductive layer. The thermal assembly can be configured to dissipate thermal energy generated by the processing circuit. The thermal assembly may include a first thermally conductive layer. The thermal assembly may further include an adhesive layer coupled with the first thermally conductive layer. The thermal assembly may further include a second thermally conductive layer coupled with the adhesive layer. In some embodiments, the first thermally conductive layer and the second thermally conductive layer may include a non-metal material.
In another aspect, an electronic device is described. The electronic device may include a display configured to present visual information. The electronic device may further include an enclosure coupled with the display. The enclosure may define an internal volume configured to carry components. The components may include a circuit board that carries a processing circuit. The components may include an antenna electrically coupled to the circuit board. The components may further include a metal wall located on the circuit board. The components may further include a shield. The shield may include a conductive tape adhered to the metal wall. The conductive tape may be configured to shield the antenna from radio frequency shield generated by the processing circuit. The shield may further include a thermal assembly adhered with the conductive tape. The thermal assembly may provide a thermal dissipation path for thermal energy generated by the processing circuit.
In another aspect, a shield suitable for use in an electronic device is described. The shield may include a first electrically conductive tape. The shield may further include a first electrically conductive tape adhered to the first electrically conductive tape. The shield may further include a thermal assembly positioned between the first electrically conductive tape and the second electrically conductive tape. The thermal assembly may include a first thermally conductive layer. The thermal assembly may further include a first adhesive layer adhered to the first thermally conductive layer. The thermal assembly may further include a second thermally conductive layer adhered to the first adhesive layer. The thermal assembly may further include a second adhesive layer adhered to the second thermally conductive layer. In some embodiments, the first thermally conductive layer and the second thermally conductive layer may include a non-metal material.
Other systems, methods, features and advantages of the embodiments will be, or will become, apparent to one of ordinary skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description and this summary, be within the scope of the embodiments, and be protected by the following claims.
The disclosure will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements, and in which:
Those skilled in the art will appreciate and understand that, according to common practice, various features of the drawings discussed below are not necessarily drawn to scale, and that dimensions of various features and elements of the drawings may be expanded or reduced to more clearly illustrate the embodiments of the present invention described herein.
Reference will now be made in detail to representative embodiments illustrated in the accompanying drawings. It should be understood that the following descriptions are not intended to limit the embodiments to one preferred embodiment. To the contrary, it is intended to cover alternatives, modifications, and equivalents as can be included within the spirit and scope of the described embodiments as defined by the appended claims.
In the following detailed description, references are made to the accompanying drawings, which form a part of the description and in which are shown, by way of illustration, specific embodiments in accordance with the described embodiments. Although these embodiments are described in sufficient detail to enable one skilled in the art to practice the described embodiments, it is understood that these examples are not limiting such that other embodiments may be used, and changes may be made without departing from the spirit and scope of the described embodiments.
The following disclosure relates to a shield for use with electronic devices, such as portable electronic device, including smartphones, tablet computing devices, and laptops (as non-limiting examples). The shield is designed to cover, or overlay, a circuit board of an electronic device, as well as the components on the circuit board. Based upon its position, the shield can provide several benefits. For example, the shield may include conductive adhesives, such as electrically conductive tapes, that shield wireless components (e.g., antennae and wireless circuitry) in the electronic device from radio frequency (“RF”) interference, including electromagnetic interference (“EMI”), generated by one or more components on the circuit board. The electrically conductive tape can also mitigate desense for the wireless components. Additionally, the shield may include a thermal assembly that includes thermally conductive layers designed to draw away thermal energy generated by one or more components located on the circuit board. The electrically conductive tape may include a metal (e.g., copper) or metals, while the thermal assembly may use multiple layers formed from a material (or materials) of relatively high thermal conductivity. For example, at least some layers of the thermal assembly may include graphite, which provides enhanced thermal energy dissipation and less rigidity.
While the electrically conductive tape may include metal, both the electrically conductive tape and the thermally conductive layers are generally non-rigid bodies (as compared to sheet metal, for example). For instance, the electrically conductive tape may be flexible in a manner similar to that of adhesive tapes commonly known in the art. Also, based on adhesive properties of the electrically conductive tape, the shield can secure with a structure located on the circuit board, such as a metal wall (or metal perimeter), thereby forming a cage (based on the shield and the metal wall) to prevent propagation of RF interference generated by one or more components on the circuit board. In this manner, the shield, including its components and layers, may not require any openings, or through holes, as the adhesive properties, and not fasteners, are used to secure the shield with the metal wall. As a result, the shield can define a body with a continuous surface area that is unsusceptible, or at relatively less susceptible, to RF emission that would otherwise pass through the openings required for fasteners used to secure a traditional shield.
Moreover, by forming the thermal assembly and the electrically conductive tape from non-rigid bodies, the shield can provide a more compliant body. In this manner, the shield can more readily secure with the circuit board, and in particular, with the metal wall located on the circuit board. The compliant properties of the shield allow the shield to adjust and account for, or conform to, manufacturing variations of the metal wall due to the specified dimensional tolerances allowed for the metal wall. Also, the compliant properties of the shield allow the shield to easily bend, thereby minimizing or preventing an applied force by the shield to the metal wall (to which the shield is secured). As a result, the metal wall is less likely to undergo any bending, warping, or otherwise becoming damaged, and the likelihood of the metal wall breaking away from the circuit board is significantly reduced. In other words, the assembly process between the shield and the metal wall does not cause the metal wall to become non-compliant with respect to design specifications provided for the electronic device.
These and other embodiments are discussed below with reference to
As shown, electronic device 100 may include an enclosure 102, or housing, that provides a protective body as well as defines an internal volume, or cavity, that receives several components, such as processing circuitry, memory circuitry, batteries, speaker modules, microphones, cameras, antennae, and flexible circuits that electrically couple together the aforementioned components. Enclosure 102 may include a metal, such as aluminum, steel (including stainless steel), or a metal alloy (as non-limiting examples). Alternatively, enclosure 102 may include non-metals, such as plastic or ceramic (as non-limiting examples).
Electronic device 100 may further include a display assembly 104. Display assembly 104 may include a touchscreen with capacitive touch input capabilities designed to receive user inputs and/or gestures. Electronic device 100 may further include a protective layer 106 that covers/overlays display assembly 104. Protective layer 106 can be formed from a transparent material, such as glass, plastic, or sapphire (as non-limiting examples). In order to receive additional inputs, electronic device 100 may further include a button 108a and a button 108b (each protruding through a respective opening of enclosure 102). Buttons 108a and 108b may be depressed to actuate a respective switch (not shown in
Electronic device 100 may include a port 112 designed to electrically couple with an external source (not shown in
Electronic device 100 may further include a shield 130 that covers, or at least partially covers, circuit board 128. Accordingly, shield 130 may cover several aforementioned electronic components (shown as dotted lines) that are located on circuit board 128. Shield 130 is designed to provide RF shielding, including EMI shielding, thermal energy dissipation, and desense mitigation. The various features of shield 130 will be shown and described below. Additionally, electronic device 100 may further include a cowling 132a and a cowling 132b, each of which cover a portion of circuit board 128. Cowlings 132a and 132b can be used to secure several components, such as connectors, to enclosure 102. As shown in
Also, as shown, a wall 136 is disposed on circuit board 128. Wall 136 may include a metal wall formed from sheet metal, as a non-limiting example. Wall 136 defines a perimeter around at least some components located on circuit board 128, such as components 134a and 134b. Further, wall 136 may define a platform, or receiving surface, for shield 130. Further, shield 130 may include adhesive properties that allow shield 130 to adhere to wall 136. For example, shield 130 may include an adhesive tape. When shield 130 is adhered to wall 136, shield 130 and wall 136 may form a cage that blocks RF interference by components 134a and 134b from propagating throughout electronic device 100 (shown in
Further, shield 130 may include a thermal assembly 150 formed from several thermally conductive layers. For example, thermal assembly 150 may include a thermally conductive layer 152a, a thermally conductive layer 152b, a thermally conductive layer 152c, and a thermally conductive layer 152d. Thermally conductive layers 152a, 152b, 152c, and 152d may be referred to as a first thermally conductive layer, a second thermally conductive layer, a third thermally conductive layer, and a fourth thermally conductive layer, respectively. In some embodiments, each of thermally conductive layers 152a, 152b, 152c, and 152d is formed from a non-metal material, such as graphite. Accordingly, each of thermally conductive layers 152a, 152b, 152c, and 152d may define a graphite layer. Due in part to material makeup of the graphite (e.g., fibers), each of thermally conductive layers 152a, 152b, 152c, and 152d may define relatively flexible layer, as opposed to a rigid metal layer.
In order to hold thermally conductive layers 152a, 152b, 152c, and 152d together, thermal assembly 150 includes several adhesive layers. For example, thermal assembly 150 may include an adhesive layer 154a, an adhesive layer 154b, and an adhesive layer 154c. Adhesive layers 154a, 154b, and 154c may be referred to as a first adhesive layer, a second adhesive layer, and a third adhesive layer, respectively. In some embodiments, each of adhesive layers 154a, 154b, and 154c includes a pressure sensitive adhesive designed to activate adhesive properties when a threshold force is applied. Generally, for n thermally conductive layers, thermal assembly 150 includes n−1 adhesive layers. Also, the thickness of each of adhesive layers 154a, 154b, and 154c is substantially small enough so as not prevent, or at least not substantially prevent, thermal energy passage through each individual layer.
Shield 130 may further include a structural layer 156 formed from one or more structural components. In some embodiments, structural layer 156 is formed from a polyester film that includes biaxially-oriented polyethylene terephthalate (“BoPET”), as a non-limiting example, BoPET may also be referred to as MYLAR®. Structural layer 156 may provide shield 130 with additional strength and stability, which can be particularly beneficial when metal layers are not integrated with shield 130. As shown, structural layer 156 is defined by a structural component 158a, a structural component 158b, a structural component 158c, and a structural component 158d. When assembled, the aforementioned structural components of structural layer 156 may be adhered to conductive layer 140b. In this regard, conductive layer 140b may include a two-sided adhesive layer.
Also, in order to accommodate certain components of circuit board 128 (shown in
In some embodiments, the size and shape of the conductive layers (such as conductive layers 140a and 140b) may differ from that of the thermally conductive layers (such as the thermally conductive layers 152a, 152b, and 152c). For example, conductive layer 140a (representative of the size and shape of conductive layer 140b) includes a dimension 143a along the X-axis and a dimension 143b along the Y-axis, while thermally conductive layer 152a (representative of the size and shape of thermally conductive layers 152b and 152c) includes a dimension 153a along the X-axis and a dimension 153b along the Y-axis. The X-, Y-, and Z-axes shown in
Also, in some embodiments, the size and shape of thermally conductive layers 152a, 152b, and 152c differs from that of thermally conductive layer 152d. For example, thermally conductive layer 152d includes a dimension 155a along the X-axis. Dimension 155a of thermally conductive layer 152d is less than dimension 153a of thermally conductive layer 152a. Accordingly, thermally conductive layer 152a includes a greater surface area (defined along an X-Y plane) as compared to that of thermally conductive layer 152d. In other words, thermally conductive layer 152a is larger than thermally conductive layer 152d. Also, by comparison, conductive layer 140a is larger than thermally conductive layer 152d. The difference in size and shape among thermally conductive layers 152a, 152b, 152c, and 152d allows thermal assembly 150 to provide more or less thermal energy dissipation capabilities as needed, while also accommodating some components of circuit board 128 (shown in
Shield 130 may provide several advantages over traditional shields. For example, the use of non-rigid bodies (i.e., graphite and no sheet metal) by shield 130 for thermal conductivity, can reduce the overall weight and cost of shield 130. Further, due in part to the use of graphite, the thermal energy transfer capabilities of shield 130 may increase, as compared to using a metal layer for thermal energy transfer. Finally, by eliminating openings, or through holes, shield 130 reduces EMI leaks and provides enhanced desense mitigation, as opposed to a shield that requires openings for fasteners.
Additionally, based on the non-rigid properties of conductive layers 140a and 140b, both conductive layers 140a and 140b are compliant bodies that can conform to the position/location of wall 136. For example, prior to the assembly of shield 130 with wall 136, conductive layers 140a and 140b are both generally flat. However, subsequent to the assembly of shield 130 with wall 136, at least one of conductive layers 140a and 140b can bend or deform so that at least one of conductive layers 140a and 140b is positioned onto wall 136 without applying a bending force that bends or otherwise reshapes wall 136. As shown in
Further, at least some of the thermal energy flowing in direction 166a passes into thermal assembly 150 of shield 130. In this manner, the trajectory/direction of the thermal energy flowing into thermal assembly 150 begins to flow in a direction 166c along the Y-axis through thermal assembly 150, with the Y-axis being generally parallel to thermal assembly 150. Accordingly, thermal assembly 150 can redirect the heat to flow in a different direction, which may limit or prevent other components from receiving the thermal energy, such as display assembly 104 (shown in
Further, shield 230 may include a thermal assembly 250 defined by a thermally conductive layer 252. As shown, thermally conductive layer 252 represents a single thermally conductive layer. In order to maintain thermally conductive layer 252 intact, thermal assembly 250 may include an adhesive layer 254a and an adhesive layer 254b. Also, shield 230 may further include a structural layer 256 formed from one or more structural components.
Although thermal assembly 250 includes fewer thermally conductive layers as compared to thermal assembly 150 (shown in
It should therefore be understood that the thickness of thermal assemblies may vary based upon the number of thermally conductive layers used, which may be selected based upon required thermal characteristics and/or size and volume constraints. Also, in some embodiments, the size and shape of the conductive layers (such as conductive layers 240a and 240b) may differ from that of thermally conductive layer 252 in that each of conductive layers 240a and 240b are larger than thermally conductive layer 252. Also, while
While the foregoing embodiments show and describe adhesive layers having a size and shape that generally matches the size and shape of thermally conductive layers, adhesive layers may include alternate sizes and shapes. For example,
While
In step 502, a thermal assembly is secured with a first conductive layer. The thermal assembly may include one or more thermally conductive layers. Further, the thermally conductive layer(s) may include a non-metal, such as graphite. Also, the first conductive layer may include an electrically conductive tape. In this regard, the first conductive layer is generally flexible.
In step 504, the thermal assembly is secured with a second conductive layer. Also, the second conductive layer may include an electrically conductive tape. For example, the second conductive layer may include a copper tape. Similar to the first conductive layer, the second conductive layer is generally flexible. Also, in some embodiments, the second conductive layer may include a cut out, or opening, having a size and shape capable of receiving a heat-generating component, such as an integrated circuit.
In step 506, a structural layer is secured with the second conductive layer. The structure layer may include one or more structural components designed to enhance the structural rigidity of the shield. For example, the structural layer may include BoPET (as a non-limiting example) In some embodiments, the one or more structural components of the structural layer define an opening or space/void that is aligned with the cut out.
According to some embodiments, electronic device 600 can include a display unit 620 capable of presenting a user interface that includes icons (representing software applications), textual images, and/or motion images. In some examples, each icon can be associated with a respective function that can be executed by one or more processors 610. In some cases, display unit 620 includes a display layer (not illustrated), which can include a liquid-crystal display (LCD), light-emitting diode display (LED), or the like. According to some embodiments, display unit 620 includes a touch input detection component and/or a force detection component that can be configured to detect changes in an electrical parameter (e.g., electrical capacitance value) when the user's appendage (acting as a capacitor) comes into proximity with display unit 620 (or in contact with a transparent layer that covers display unit 620). Display unit 620 is connected to one or more processors 610 via one or more connection cables 622.
According to some embodiments, electronic device 600 can include one or more sensors 630 capable of providing an input to one or more processors 610 of electronic device 600. One or more sensors 630 may include a temperature sensor, as a non-limiting example. One or more sensors 630 is/are connected to one or more processors 610 via one or more connection cables 632.
According to some embodiments, electronic device 600 can include one or more input/output components 640. In some cases, one or more input/output components 640 can refer to a button or a switch that is capable of actuation by the user. When one or more input/output components 640 is/are used, one or more input/output components 640 can generate an electrical signal that is provided to one or more processors 610 via one or more connection cables 642.
According to some embodiments, electronic device 600 can include a power supply 650 that is capable of providing energy to the operational components of electronic device 600. In some examples, power supply 650 can refer to a rechargeable battery. Power supply 650 can be connected to one or more processors 610 via one or more connection cables 652. Power supply 650 can be directly connected to other devices of electronic device 600, such as one or more input/output components 640. In some examples, electronic device 600 can receive power from another power sources (e.g., an external charging device) not shown in
According to some embodiments, electronic device 600 can include memory 660, which can include a single disk or multiple disks (e.g., hard drives), and includes a storage management module that manages one or more partitions within memory 640. In some cases, memory 660 can include flash memory, semiconductor (solid state) memory or the like. Memory 660 can also include a Random Access Memory (“RAM”) and a Read-Only Memory (“ROM”). The ROM can store programs, utilities or processes to be executed in a non-volatile manner. The RAM can provide volatile data storage, and stores instructions related to the operation of the electronic device 600. In some embodiments, memory 660 refers to a non-transitory computer readable medium. One or more processors 610 can also be used to execute software applications. In some embodiments, a data bus 662 can facilitate data transfer between memory 660 and one or more processors 610.
According to some embodiments, electronic device 600 can include wireless communications components 670. A network/bus interface 672 can couple wireless communications components 670 to one or more processors 610. Wireless communications components 670 can communicate with other electronic devices via any number of wireless communication protocols, including at least one of a global network (e.g., the Internet), a wide area network, a local area network, a wireless personal area network (WPAN), or the like. In some examples, wireless communications components 670 can communicate using NFC protocol, BLUETOOTH® protocol, or WIFI® protocol.
The various aspects, embodiments, implementations or features of the described embodiments can be used separately or in any combination. Various aspects of the described embodiments can be implemented by software, hardware or a combination of hardware and software. The described embodiments can also be embodied as computer readable code on a computer readable medium for controlling manufacturing operations or as computer readable code on a computer readable medium for controlling a manufacturing line. The computer readable medium is any data storage device that can store data which can thereafter be read by a computer system. Examples of the computer readable medium include read-only memory, random-access memory, CD-ROMs, HDDs, DVDs, magnetic tape, and optical data storage devices. The computer readable medium can also be distributed over network-coupled computer systems so that the computer readable code is stored and executed in a distributed fashion.
The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the described embodiments. However, it will be apparent to one skilled in the art that the specific details are not required in order to practice the described embodiments. Thus, the foregoing descriptions of the specific embodiments described herein are presented for purposes of illustration and description. They are not targeted to be exhaustive or to limit the embodiments to the precise forms disclosed. It will be apparent to one of ordinary skill in the art that many modifications and variations are possible in view of the above teachings.
It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.
The present application claims the benefit of U.S. Provisional Application No. 62/991,468, entitled “CONDUCTIVE SHIELD FOR AN ELECTRONIC DEVICE,” filed Mar. 18, 2020, the content of which is incorporated herein by reference in its entirety for all purposes.
Number | Date | Country | |
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62991468 | Mar 2020 | US |