PATENT DOCUMENT

Publication Number: US-7729131-B2
Application Number: US-65012207-A
Country: US
Kind Code: B2

Title: Multiple circuit board arrangements in electronic devices

Abstract:
Electronic devices can be provided with at least one first circuit component coupled to a first circuit board, at least one second circuit component coupled to a second circuit board, and a mating assembly coupled to the boards for holding them in a vertical stack. The first circuit components can face the second circuit components in the stack. One or more of the first circuit components can be horizontally offset from one or more of the second circuit components in the stack to reduce the thickness of the mated circuit boards. Portions of the circuit boards and the mating assembly can shield the circuit components of the stack from electromagnetic interference.

Claims:
1. An electronic device, comprising:
 a first board; 
 first circuit components coupled to a first circuitry side of the first board; 
 a first board-to-board coupler coupled to the first circuitry side of the first board; 
 a second board; 
 second circuit components coupled to a second circuitry side of the second board; 
 a second board-to-board coupler coupled to the second circuitry side of the second board; 
 a first interference shield structure having a first planar portion and first side portions coupled to a first shielding side of the first board opposite the first circuitry side; and 
 a second interference shield structure having a second planar portion and second side portions coupled to a second shielding side of the second board opposite the second circuitry side, 
 wherein the first and second interference shield structures mate with each other to hold the first board and the second board in a vertical stack, wherein the first and second interference shields substantially surround the first and second circuit components to provide electromagnetic shielding for the first and second circuit components, wherein the first and second board-to-board couplers are electrically connected in the vertical stack, wherein the first circuitry side and the first circuit components face the second circuitry side and the second circuit components in the vertical stack, wherein each of the first circuit components is horizontally offset from each of the second circuit components in the vertical stack, and wherein there is no shielding layer interposed between the facing first and second circuitry sides of the first and second boards. 
 
   
   
     2. The electronic device of  claim 1 , wherein the first circuit components comprise a tallest first circuit component and wherein the tallest first circuit component is substantially adjacent to the second board in the vertical stack. 
   
   
     3. The electronic device of  claim 1 , wherein the first circuit components comprise a tallest first circuit component and wherein the tallest first circuit component is horizontally offset from each of the second circuit components in the vertical stack. 
   
   
     4. The electronic device of  claim 1 , wherein the first circuit components comprise a tallest first circuit component having a height, wherein the first and second boards are separated by a distance in the vertical stack and wherein the distance between the first and second boards in the vertical stack is substantially equal to the height of the tallest first circuit component. 
   
   
     5. The electronic device of  claim 1 , further comprising an insulating layer between at least a portion of the first board and at least a portion of the second board in the vertical stack. 
   
   
     6. An electronic device having a housing with a substantially planar surface, comprising:
 a first board within the housing that occupies a region partially overlapping with the planar surface of the housing; 
 first circuit components coupled to the first board; 
 a first board-to-board coupler coupled to the first board; 
 a second board within the housing; 
 second circuit components coupled to the second board; 
 a second board-to-board coupler coupled to the second board; 
 a first interference shield structure having a first planar portion and first side portions coupled to the first board; 
 a second interference shield structure having a second planar portion and second side portions coupled to the second board, 
 wherein the first and second interference shield structures mate with each other and hold the first and second boards in a stack, wherein the first and second interference shield structures substantially surround the first and second circuit components in the stack, wherein the first and second board-to-board couplers are electrically connected in the stack, wherein the first circuit components face the second circuit components in the stack, wherein each of the first circuit components is horizontally offset from each of the second circuit components in the stack, and wherein there is no shielding layer interposed between the first and second boards; and 
 an antenna that is located within the housing and outside the region occupied by the first board. 
 
   
   
     7. The electronic device of  claim 6 , wherein the first circuit components extend from the first board towards the second board in the stack and wherein the second circuit components extend from the second board towards the first board in the stack. 
   
   
     8. The electronic device of  claim 6 , wherein the first and second interference shield structures serve as an electromagnetic shield for the first circuit components in the stack. 
   
   
     9. The electronic device of  claim 7 , wherein the first and second interference shield structures serve as an electromagnetic shield for the first circuit components in the stack. 
   
   
     10. A method for arranging multiple circuit boards in an electronic device, wherein the device includes a first circuit board with a first interference shield structure having a first planar side and first side portions, a second circuit board with a second interference shield structure having a second planar side and second side portions, first circuit components, and second circuit components, and wherein the first portions have outer sides and the second side portions have inner sides, the method comprising:
 disposing the first circuit components on the first circuit board; 
 disposing the second circuit components on the second circuit board; 
 disposing the first interference shield structure on the first circuit board; 
 disposing the second inference shield structure on the second circuit board; and 
 mating the outer sides of the first side portions against the inner sides of the second of the second side portions in a mated configuration that holds the first circuit board and the second circuit board in a vertical stack, wherein the first and second side portions are horizontally offset from one another in the mated configuration, wherein the first circuit components face the second circuit components in the vertical stack, wherein each of the first circuit components is horizontally offset from each of the second circuit components in the vertical stack, wherein the first and second interference shield structures substantially surround the first and second circuit components in the vertical stack to provide electromagnetic shielding for the first and second circuit components, and wherein there is no shielding layer interposed between the first circuit components and the second circuit components. 
 
   
   
     11. The method of  claim 10 , wherein the second circuit components comprise a tallest circuit component and wherein disposing the second circuit components comprises selectively placing the second circuit components in a configuration that horizontally offsets the tallest circuit component from each of the first circuit components in the vertical stack. 
   
   
     12. The electronic device defined in  claim 1 , wherein the first circuit components comprise a tallest first circuit component having a first height, wherein the second circuit components comprise a tallest second circuit component having a second height, wherein the first and second boards are separated by a distance in the vertical stack, and wherein the distance between the first and second boards in the vertical stack is less than a sum of the first and second heights. 
   
   
     13. The electronic device defined in  claim 6 , wherein the first circuit components comprise a tallest first circuit component having a first height, wherein the second circuit components comprise a tallest second circuit component having a second height, wherein the first and second boards are separated by a distance in the stack, and wherein the distance between the first and second boards in the stack is less than a sum of the first and second heights. 
   
   
     14. The method defined in  claim 10  wherein the first circuit components comprise a tallest first circuit component having a first height and wherein the second circuit components comprise a tallest second circuit component having a second height, the method further comprising:
 separating the first and second boards by a distance in the vertical stack; and 
 disposing the first and second boards so that the distance between the first and second boards in the vertical stack is less than a sum of the first and second heights.

Description:
BACKGROUND OF THE DISCLOSURE 
   The present invention can relate to apparatus and methods for arranging multiple circuit boards in an electronic device. 
   In some cases, an electronic device can include a housing with one or more electrical circuit components and a circuit board. The circuit board can be used to mechanically support and electronically interconnect the one or more electrical circuit components of the device. 
   In some cases, high frequency communication signals can be transmitted and/or received by the device, and it is, therefore, generally desirable to shield the circuit board and its circuit components from electromagnetic interference (EMI) caused by such high frequency communication. However, the various amounts of electrical circuit components that may be coupled to the circuit board, as well as the one or more shielding layers that may be used to prevent EMI on the board, create significant challenges to manufacturing smaller and thinner electronic devices. 
   SUMMARY OF THE DISCLOSURE 
   Apparatus and methods for coupling and shielding multiple circuit boards in an electronic device are provided. 
   According to a particular embodiment of the present invention, an electronic device is provided that includes at least one first circuit component coupled to a first board, at least one second circuit component coupled to a second board, and a mating assembly coupled to the first board and the second board for holding the first board and the second board in a vertical stack. The one or more first circuit components can face the one or more second circuit components in the vertical stack. In certain embodiments, one or more of the first circuit components can be horizontally offset from one or more of the second circuit components in the vertical stack. In other embodiments, the tallest of the first components can be substantially adjacent the second board in the vertical stack. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The above and other features of the present invention, its nature and various advantages will become more apparent upon consideration of the following detailed description, taken in conjunction with the accompanying drawings, in which like reference characters refer to like parts throughout, and in which: 
       FIG. 1  is a perspective view of an exemplary electronic device in accordance with the principles of the present invention; 
       FIG. 2  is an exploded perspective view of the electronic device of  FIG. 1 , but with the housing omitted; 
       FIG. 3  is a horizontal cross-sectional view of a portion of the electronic device of  FIGS. 1 and 2 , taken from line  3 - 3  of  FIG. 2 ; 
       FIG. 4  is a horizontal cross-sectional view of a portion of the electronic device of  FIGS. 1-3 , taken from line  4 - 4  of  FIG. 2 ; 
       FIG. 5  is a vertical cross-sectional view of a portion of the electronic device of  FIGS. 1-4 , taken from line  5 - 5  of  FIG. 2 ; 
       FIG. 6  is a vertical cross-sectional view of the electronic device of  FIGS. 1-5 , taken from line  6 - 6  of  FIG. 1 ; 
       FIG. 7  is a vertical cross-sectional view, similar to  FIG. 6 , of an alternative embodiment of an electronic device in accordance with the principles of the present invention; and 
       FIG. 8  is a perspective view, similar to  FIG. 1 , of yet another alternative embodiment of an electronic device in accordance with the principles of the present invention, but with a portion of the housing and I/O components omitted. 
   

   DETAILED DESCRIPTION OF THE DISCLOSURE 
   Apparatus and methods for arranging multiple circuit boards in an electronic device are provided and described with reference to  FIGS. 1-8 . 
     FIGS. 1-6  illustrate an exemplary electronic device that can incorporate the present invention. The term “electronic device” can include, but is not limited to, music players, video players, still image players, game players, other media players, music recorders, video recorders, cameras, other media recorders, radios, medical equipment, calculators, cellular telephones, other wireless communication devices, personal digital assistants, remote controls, pagers, laptop computers, printers, or combinations thereof. In some cases, the electronic devices may perform a single function (e.g., an electronic device dedicated to playing music) and, in other cases, the electronic devices may perform multiple functions (e.g., an electronic device that plays music, displays video, stores pictures, and receives and transmits telephone calls). 
   In any case, these electronic devices are generally any portable, mobile, hand-held, or miniature electronic device that may allow a user to listen to music, play games, record videos, take pictures, and/or conduct telephone calls, for example, wherever the user travels. Miniature electronic devices may have a form factor that is smaller than that of hand-held electronic devices, such as an iPod™ available by Apple Computer, Inc. of Cupertino, Calif. Illustrative miniature electronic devices can be integrated into various objects that include, but are not limited to, watches, rings, necklaces, belts, accessories for belts, headsets, accessories for shoes, virtual reality devices, other wearable electronics, accessories for sporting equipment, accessories for fitness equipment, key chains, or any combination thereof. Alternatively, electronic devices of the present invention may not be portable at all. 
   Electronic device  10  can have one or more input/output (I/O) components, such as I/O components  12 A- 12 D, at least partially disposed within a housing  14 . The I/O components can include any type of component that receives and/or transmits digital and/or analog data (e.g., audio data, video data, radio frequency data, other types of data, or a combination thereof). For example, I/O component  12 A may be a display that provides graphic images to a user, I/O component  12 B may be a user input component that can permit a user to input data into the electronic device, I/O component  12 C may be an antenna that can permit electronic device  10  to interact with a computer or other device, and I/O component  12 D may be a media input/output connector that can communicate media data to an accessory. Accessories can include, but are not limited to, docks, printers, external storage devices, external displays, speakers, lanyards having headphones and microphones coupled thereto, and other audio and/or visual input/output devices. 
   In one embodiment, I/O component  12 B may be a scroll wheel similar to that used by the iPod™ device, which may include one or more buttons for selecting software entries and a capacitive touchpad. In other alternative embodiments, user I/O component  12 B may include, for example, one or more buttons, a touchpad, a touch-screen display, electronics for accepting voice commands, infrared ports, ejectable smart card assemblies, or combinations thereof. 
   In one embodiment of the present invention, I/O component  12 C may be an antenna capable of transmitting and receiving data from a computer or another device. In another embodiment, component  12 C may be a multiple-pin connector having 30 pins, for example, that transmit data to and from the electronic device. Media connector I/O component  12 D can include, for example, an audio connector that transmits audio data to speakers or headphones and/or receives audio data from a microphone. Alternatively, media connector  12 D can transmit and/or receive, for example, video data, still image data, games data, or other media data known in the art or otherwise. Media connector  12 D also can transmit and/or receive combinations of media data. 
   Housing  14  of electronic device  10  can be designed to protect the I/O components (e.g., I/O components  12 A- 12 D), one or more electrical circuit components, and at least two circuit boards coupled thereto. For example, as shown in  FIG. 2 , each of I/O components  12 A- 12 D may be coupled to respective electrical circuit components  20 A- 20 D of one or both of two circuit boards  16  and  18 , via respective coupling circuits  19 A- 19 D. Each of coupling circuits  19 A- 19 D can be any flexible printed circuit (FPC), including one-sided, double-sided, multi-layer, dual access, rigid-flex FPCs, or combinations thereof. In alternative embodiments, any of coupling circuits  19 A- 19 D can be replaced with ribbon cables, other types of cables, wires, other types of data transmission lines, or combinations thereof. 
   In one embodiment, each of I/O components  12 A- 12 D and electrical circuit components  20 A- 20 D can be coupled to a respective end of its respective coupling circuit  19 A- 19 D using surface mount technology (SMT), soldering techniques, or through-hole constructions. In alternative embodiments, each I/O component  12  and/or electrical circuit component  20  can be electrically coupled to an end of its respective coupling circuit  19  using other methods known in the art or otherwise. Therefore, when I/O components  12  are physically and electrically coupled to electrical circuit components  20  of boards  16  and  18  via coupling circuits  19 , one or more of boards  16  and  18  may communicate with each of I/O components  12  of device  10  concurrently in order for the device to function properly. 
   In addition to each of electrical circuit components  20 A- 20 D that may be coupled to a respective I/O component via a respective coupling circuit, device  10  may also include additional electrical circuit components  20  coupled to the two or more circuit boards. For example, device  10  can also include electrical circuit component  20 E coupled to circuit board  16  (see, e.g.,  FIG. 3 ) and electrical circuit component  20 F coupled to circuit board  18  (see, e.g.,  FIG. 4 ). While each one of electrical circuit components  20 A- 20 D may be of any suitable type of I/O communications circuitry, each of additional electrical circuit components  20 E and  20 F may be of any suitable type of circuitry, including, but not limited to, a processor, a storage device, communications circuitry, a bus, a power supply for powering the device, or any combination thereof, for example. 
   A bus circuit component  20  of device  10  may provide a data transfer path for transferring data, to, from, or between at least a processor, a storage device, and/or communications circuitry. A processor circuit component  20  of device  10  may control the operation of many functions and other circuitry included in the device  10 . For example, a processor component may receive user inputs from I/O component  12 B via electrical circuit component  20 B and drive I/O component  12 A via electrical circuit component  20 A. Alternatively, a processor component may be a codec, an analog-to-digital converter, a digital-to-analog converter, or any other suitable type of processor, for example. 
   A storage device circuit component  20  of device  10  may include one or more storage mediums, including, for example, a hard-drive, a permanent memory such as ROM, a semi-permanent memory such as RAM, or cache, that may store media (e.g., music and video files), software (e.g., for implementing functions on device  10 ), wireless connection information (e.g., information that may enable device  10  to establish wireless communication with another device or server), subscription information (e.g., information that keeps track of podcasts, television shows, or other media that the user subscribes to), and any other suitable data. 
   A communications circuitry component  20  of device  10  may include circuitry for wireless communication (e.g., short-range and/or long-range communication). For example, the wireless communication circuitry of device  10  may be wi-fi enabling circuitry that permits wireless communication according to one of the 802.11 standards. Other wireless protocol standards could also be used, either in alternative or in addition to the identified protocol. Another network standard may be Bluetooth®. 
   A communications circuitry component  20  may also include circuitry that enables device  10  to be electrically coupled to another device (e.g., a computer or an accessory device) and communicate with that other device. Furthermore, additional types of electrical circuit components  20  may be provided by device  10  for sending and receiving media, including, but not limited to, microphones, amplifiers, digital signal processors (DSPs), image sensors (e.g., charge coupled devices (CCDs)) or optics (e.g., lenses, splitters, filters, etc.), receivers, transmitters, transceivers, and the like. 
   Each of the plurality of circuit boards (e.g., boards  16  and  18 ) of the present invention can be any type of board, including, but not limited to, printed circuit boards (PCBs), logic boards, printed wiring boards, etched wiring boards, and other known boards, that may be used to mechanically support and electronically connect the one or more electrical circuit components (e.g., electrical circuit components  20 ) coupled thereto. Each circuit board may be constructed using one or more layers of a non-conductive substrate and signal conducting pathways. 
   The signal conducting pathways can exist in one or more layers or in each layer of the non-conductive substrate. The signal conducting layers, sometimes referred to as traces, members, or leads, may be a metal conductive material (e.g., copper or gold) or an optical conductive material (e.g., fiber optics). 
   In order to manufacture device  10  with a smaller surface area, rather than coupling all of components  20  on one larger circuit board, electrical circuit components  20  can be coupled to one of two smaller circuit boards  16  and  18  that may be stacked on top of one another. By placing some of components  20  on a first board (e.g., components  20 A,  20 B, and  20 E on a first side  15  of board  16 ) and some of components  20  on a second board (e.g., components  20 C,  20 D, and  20 F on a first side  15  of board  18 ), the total surface area consumed by the boards can be reduced when the boards are stacked. 
   The total surface area created by two circuit boards in a stacked combination is considerably less than the total surface are created by the same two boards placed side by side in substantially the same plane. For example, the surface area created by boards  16  and  18  in a stacked configuration (see, e.g., the surface area created by length LM and depth DM of  FIGS. 2 and 4 ) is by at least a factor less than the total surface area created by boards  16  and  18  when they are merely placed side by side in substantially the same plane (not shown, but see, e.g., the total of not only the surface area created by length LM and depth DM of  FIGS. 2 and 4  but also the surface area created by length L 1  and depth D 1  of  FIG. 3 ). Therefore, by splitting up components  20  of device  10  amongst two or more circuit boards, not only may the surface area of each board be reduced due to the lower number of components on that individual board, but the total surface area of the device may also be reduced by stacking the two smaller circuit boards on top of one another as opposed to placing them side by side. 
   In certain embodiments, one or more of the plurality of circuit boards, as well as the circuit components coupled thereto, can be designed specifically for one or more particular purpose and can be entirely self-reliable. For example, circuit board  16  and components  20  coupled thereto (e.g., components  20 A,  20 B, and  20 E) can be specifically designed and dedicated to recording and playing music, while circuit board  18  and components  20  coupled thereto (e.g., components  20 C,  20 D, and  20 F) can be specifically designed and dedicated to receiving and transmitting wireless communications. In certain embodiments, one or more of such specifically designed boards (e.g., boards  16  and  18 ) may be completely independent and may not need or be able to share any capabilities or circuit components  20  with the other board or boards of the device. 
   These specifically designed and dedicated circuit boards can be smaller and require less electrical circuit components  20  than more generic boards that are designed to facilitate many various types of functions (e.g., playing music, displaying videos, taking pictures, and receiving telephone calls). Therefore, by splitting up components  20  of device  10  amongst two or more stacked circuit boards, not only may the surface areas of each board and the entire device be reduced, but the utility of the device may be enhanced as well. 
   While stacking the circuit boards can reduce the total surface area of the boards within the device, this stack may consequentially increase the total height or thickness of the circuit boards. Therefore, rather than stacking the circuit boards such that their respective circuit components extend away from or in the same direction as each other, the circuit boards may be stacked with their respective circuit components extending towards each other in order to reduce the total thickness of the circuit board stack. As shown in  FIGS. 2-6 , for example, each of electrical circuit components  20  may be coupled to first side  15  of one of circuit boards  16  or  18  such that, when the two boards are stacked together with first sides  15  facing each other, circuit components  20  on board  16  are extending therefrom and towards circuit components  20  on board  18 , and vice versa. 
   Device  10  can also be provided with a mating assembly for holding two or more boards in a vertical stack according to the present invention. In certain embodiments, each of any two circuit boards to be stacked can be provided with one or more of its own circuit board mating components of a mating assembly. A circuit board mating component from each of two circuit boards can interact so as to hold those two circuit boards in a fixed relationship with their respective electrical circuit components facing each other, as described above. As shown in  FIGS. 2-6 , for example, device  10  can be provided with a mating assembly that includes a board mating component  30  coupled to circuit board  16  and a board mating component  40  coupled to circuit board  18 . 
   In one embodiment, board mating component  30  can include a base portion  36  and one or more side portions  34  extending therefrom. As shown in  FIGS. 2 ,  3 ,  5 , and  6 , for example, second side  17  of circuit board  16  can be coupled to first side  35  of base portion  36 , and four side portions  34  may extend from first side  35  of base portion  36  about board  16 . Second side  17  of board  16  may be coupled to first side  35  of base portion  36  by any suitable technique, including, but not limited to, adhesives, soldering, screw points, fingers secured with metal screws or any other securable pressure/force device (e.g., rivets, nails, pins) or bonding agent or glue or laser welding or spot welding, or combinations thereof. In alternative embodiments, two or more sides  34  may be spaced such that board  16  can be held in a tight fit therebetween and against base portion  36 . 
   Board mating component  40  can be similar to board mating component  30  and can include a base portion and one or more side portions extending therefrom. In an alternative embodiment, there may be no base portion and board mating component  40  can include one or more side portions  44  extending from first side  15  of circuit board  18 . As shown in FIGS.  2  and  4 - 6 , for example, four side portions  44  may extend from first side  15  of circuit board  18  about circuit components  20  coupled thereto. In one embodiment, as shown in FIGS.  2  and  4 - 6 , side portions  44  may continuously surround circuit components  20  of board  18 . In an alternative embodiment, just as each of side portions  34  may be individually coupled to base portion  36  of mating component  30 , one or more of side portions  44  may be separately and independently coupled to board  18 . First side  15  of board  18  may be coupled to side portions  44  of mating element  40  by any suitable technique, including, but not limited to, adhesives, soldering, screw points, fingers secured with metal screws or any other securable pressure/force device (e.g., rivets, nails, pins) or bonding agent or glue or laser welding or spot welding, or combinations thereof. 
   Each of mating components  30  and  40  may be provided with corresponding mating elements that can interact to hold the two circuit boards together in a stacked relationship. As shown in  FIGS. 2 ,  5 , and  6 , for example, board mating component  30  may be provided with one or more board mating elements  32  along the outer side of one or more of side portions  34 . Likewise, board mating component  40  may be provided with one or more board mating elements  42  along the inner side of one or more of side portions  44 . 
   When mating elements  32  and  42  interact, they can retain mating components  30  and  40 , and, thus boards  16  and  18 , in a mated stack. For example, as shown in  FIG. 6 , when boards  16  and  18  are moved towards each other in the directions of arrows  21  and  23 , respectively (see, e.g.,  FIGS. 2 and 5 ), the outer sides of mating component  30  can slide against the inner sides of mating component  40  such that mating elements  32  and  42  can interact and thereby hold boards  16  and  18  in a fixed and mated relationship. 
   In one embodiment, as shown in  FIGS. 2-6 , mating elements  32  can be notches or grooves formed in side portions  34  and mating elements  42  can be nubs or balls protruding from side portions  44 . In an alternative embodiment, mating elements  32  and  42  may be provided as any suitable interlocking mechanism or technique for holding boards  16  and  18  in their mated combination, including, but not limited to, snap-fit, threaded fastener, glue, soldering, bonding agent, or combinations thereof. In yet another alternative embodiment, one or both of mating components  30  and  40  may not include its respective mating element  32  or  42 . Instead, the geometries of sides  34  and  44  can be such that they themselves create a tight fit with one another, and the tension between sides  34  and  44  can hold components  30  and  40 , and, thus, boards  16  and  18 , in their mated position. 
   Openings, cut-outs, or holes can also be provided in one or more portions of the mating components for passing coupling circuits between respective circuit components internal to the mated circuit board stack and respective I/O components external thereto. For example, as shown in  FIGS. 2-6 , openings  51  and  52  can be respectively provided in portions of mating components  30  and  40  such that, when boards  16  and  18  are in a mated stack (see, e.g.,  FIG. 6 ), openings  51  and  52  can align and pass coupling circuit  19 C therethrough. Similarly, openings  53  and  54  can be respectively provided in portions of mating components  30  and  40  such that, when boards  16  and  18  are in a mated stack, openings  53  and  54  can align and pass coupling circuit  19 D therethrough. Likewise, openings  55  and  56  can be respectively provided in portions of mating components  30  and  40  such that, when boards  16  and  18  are in a mated stack, openings  55  and  56  can align and pass coupling circuits  19 A and  19 B therethrough. 
   The geometries of mating components  30  and  40  can be such that their fixed and mated relationship may hold boards  16  and  18  apart from one another by a distance D. This distance may ensure that no electrical components of one board contact the other circuit board or the components thereon when the two boards are stacked by their mating components. 
   Distance D can be any distance that maintains at least a minimal vertical offset distance in the Z-direction between any two components of different boards that are at least partially aligned in each of the X- and Y-directions (i.e., at least partially horizontally aligned). For example, as shown in  FIGS. 3-6 , despite component  20 A of board  16  being partially aligned with component  20 F of board  18  in the Y-direction and also in the X-direction (e.g., by overlapping width W 1  of  FIG. 6 ), distance D may maintain at least a minimal vertical offset distance H 1  in the Z-direction between components  20 A and  20 F. 
   Distance D can also be any distance that maintains at least a minimal vertical offset distance in the Z-direction between any component of one board and another board itself when that component is not at least partially aligned with a component of the other board in each of the X- and Y-directions (i.e., at least partially horizontally aligned). For example, as shown in  FIGS. 3-6 , despite component  20 B of board  16  not being at least partially aligned with any component  20  of board  18  in either the X- or Y-directions, distance D may maintain at least a minimal vertical offset distance H 3  in the Z-direction between component  20 B and circuit board  18  (see, e.g.,  FIG. 6 ). 
   This distance D provided by mating components  30  and  40  between boards  16  and  18  can mitigate the potential for one or more of components  20  of one circuit board to short by contacting a component  20  of another board or that other board itself. In certain embodiments, distance D may be great enough so as to absorb any potential compression of the distance between boards  16  and  18  (and, e.g., distances H 1  and H 3 ) that may occur due to compressive forces of the user sitting on the device, for example. 
   In an alternative embodiment, any suitable non-conductive insulating material may be provided on components  20  and/or side  15  of at least one of circuit boards  16  and  18  to mitigate the potential for shorting of the device due to unintended compression of the circuit board stack. For example, as shown in  FIG. 7 , a device  10 ′ can be provided that may be substantially the same as device  10 , but that also can include layer  60 , which may be made of any suitable non-conductive insulating material, on top of first side  15  of circuit board  16  and components  20  coupled thereto. 
   In certain embodiments, distance D 1  of device  10 ′ may not maintain a minimal vertical offset distance between any two components of different boards that are at least partially horizontally aligned (e.g., minimal vertical offset distance H 1  between components  20 A and  20 F of  FIG. 6 ) because layer  60  itself can be adequate to mitigate any potential short-circuits therebetween. Also, in certain embodiments, distance D′ of device  10 ′ may not maintain a minimal vertical offset distance between any component of one board and another board itself when that component is not at least partially horizontally aligned with a component of the other board (e.g., minimal vertical offset distance H 3  between component  20 B and circuit board  18  of  FIG. 6 ) because layer  60  itself can be adequate to mitigate any potential short-circuits therebetween. 
   Non-conductive layer  60  may also include a compressible material, such as, but not limited to, a gel, foam, or sponge, and/or include a compressive device, such as a spring. The damping effect of the compressible material of non-conductive layer  60  may protect electronic device  10  from compressive forces applied thereto. In certain embodiments, compressible layer  60  can augment or absorb any potential compression of the distance between boards  16  and  18  that may occur due to compressive forces of the user sitting on the device, for example. 
   Even though the boards are mated together, the thickness of the mated combination, and, therefore, distance D, for example, can be minimized. This thickness can be minimized by selectively placing the electrical circuit components on each board such that at least certain circuit components coupled to the first board (e.g., extending away from the board in the Z-direction) are not opposed by or vertically in line with at least other certain circuit components coupled to the second board (e.g., are not at least partially horizontally aligned). 
   For example, if a first board has a centrally located stack of circuit components (see, e.g., component  20 E of board  16 ), the second board may have peripherally located vertical stacks of circuit components (see, e.g., component  20 D of board  18 ) that, when the boards are mated together, are adjacent to the centrally located circuit component. Therefore, by not opposing or being vertically in line with one another, components  20 D and  20 E, for example, can reduce the thickness of their vertical stack from that of a vertical stack in which components  20 D and  20 E do oppose or are vertically in line with one another. 
   To reduce the total thickness of this circuit board stack, in one embodiment, components  20  can be selectively placed on the circuit boards in such a way that at least the component extending the greatest distance from one of the circuit boards may be horizontally offset from the component extending the greatest distance from the other of the circuit boards. For example, as shown in  FIGS. 2-6 , component  20 B may vertically extend away from its circuit board  16  in the Z-direction to the greatest distance T 1 , and component  20 C may vertically extend away from its circuit board  18  in the Z-direction to the greatest distance T 2 . To reduce the thickness of the circuit board stack (e.g., to reduce distance D), component  20 B may be horizontally offset from component  20 C in the Y-direction and the X-direction (e.g., by an offset width W 2  of  FIG. 6 ), despite those components vertically overlapping in the Z-direction by an overlapping height H 2 . 
   By selectively placing components  20  on the circuit boards such that at least the tallest components  20 B and  20 C on their respective boards  16  and  18  are horizontally offset from one another, the thickness of the circuit board stack can be reduced. As shown, in  FIG. 6 , for example, the thickness between second sides  17  of boards  16  and  18  in their mated configuration (see, e.g., mated thickness TM) can be considerably less than the sum of the thicknesses between the tops of the tallest components  20 B and  2 C and second sides  17  of their respective boards  16  and  18  (not shown, but see, e.g., the sum of greatest distances T 1  and T 2 ). In certain embodiments, one or more additional components  20  on one circuit board may be horizontally offset from components  20  on the other circuit board to reduce the thickness of the circuit board stack (see, e.g., components  20 D and  20 E). 
   It is to be noted that, even when the tallest components are placed on their respective boards such that those components are horizontally offset from one another (e.g., components  20 B and  20 C), other components  20  of the device can be at least partially horizontally aligned. For example, although components  20 A and  20 F may be at least partially aligned with one another (e.g., by overlapping width W 1  in the X-direction), distance D may still be defined by the greatest distance that a component extends from a circuit board (e.g., distance T 1 ) along with minimal vertical offset distance H 3 . Alternatively, the distances that horizontally overlapping components  20 A and  20 F extend from their respective circuit boards (e.g., distances T 3  and T 4 ) along with minimal vertical offset distance H 1  may determine distance D, rather than greatest distance T 1  along with minimal vertical offset distance H 3 . Therefore, in certain embodiments, in order to minimize the thickness of a mated stack, each of the components may be selectively coupled to one of the circuit boards such that, when stacked, the tallest of all the components is substantially adjacent to the circuit board to which it is not coupled. In such an embodiment, the thickness of the stack can be limited only by the height of its tallest component. 
   As described above, one or more of the plurality of circuit boards of the electronic device may be specifically designed to facilitate one or more specific functions. Such specifically designed boards may be completely independent and may not need or be able to share any capabilities or circuit components with the other board or boards of the device in order to function properly. However, in alternative embodiments, two or more of the circuit boards can be coupled to one another and may share each other&#39;s electrical circuit components, thereby essentially combining to form a single circuit board. 
   For example, as shown in  FIGS. 2-6 , first side  15  of circuit board  16  can be provided with a board-to-board coupler  26  extending therefrom and first side  15  of circuit board  18  can be provided with a board-to-board coupler  28  extending therefrom. Couplers  26  and  28  can be selectively placed on boards  16  and  18 , respectively, such that they are at least partially horizontally aligned. Therefore, when mating components  30  and  40  of device  10  are in their fixed and mated relationship (see, e.g.,  FIG. 6 ), board-to-board coupler  26  may be aligned and designed to mate with complimentary board-to-board coupler  28 , thereby coupling circuit board  16  to circuit board  18 . 
   Board-to-board couplers  26  and  28  may have electrical contacts that can transmit data to and receive data from each other when they contact one another. The geometries of couplers  26  and  28  can be related to the geometries of mating components  30  and  40  such that the fixed and mated relationship of the mating components holding boards  16  and  18  apart by a distance D allows the electrical contacts of the board-to-board couplers to contact each other (see, e.g.,  FIG. 6 ). 
   In certain embodiments, a shim can be disposed between a circuit board and a board-to-board coupler and/or between two board-to-board couplers to further reinforce the board-to-board connection. For example, as shown in  FIGS. 3-6 , shim  27 , which may be made of any suitable conductive material, can be provided at the end of board-to-board coupler  26  opposite to that of circuit board  16 . When boards  16  and  18  are held in their mated relationship (see, e.g.,  FIG. 6 ), conductive shim  27  can maintain a conductive pathway between couplers  26  and  28 . Conductive shim  27  may also include a compressible material, such as, but not limited to, a gel, foam, or sponge, and/or include a compressive device, such as a spring. The damping effect of the compressible material of shim  27  may protect electronic device  10  from compressive forces applied thereto and ensure that board-to-board couplers  26  and  28  maintain contact. In certain embodiments, compressible shim  27  can augment or absorb any potential compression of the distance between boards  16  and  18  that may occur due to compressive forces of the user sitting on the device, for example. 
   Electronic devices of the present invention can be designed to transmit and/or receive electromagnetic waves for wireless communication. For example, as mentioned, I/O component  12 C of device  10  may be an antenna capable of wirelessly transmitting and/or receiving data (e.g., electromagnetic waves) from a computer or another device. Such electromagnetic waves transmitted or received by components (e.g., antenna  12 C) of the device for wireless communications may create electromagnetic interference (EMI) or radio frequency interference (RFI) with other electrical components of the device (e.g., circuit components  20  and boards  16  and  18 ). Therefore, in certain embodiments, an electronic device can be provided with one or more shields about one or more portions of the circuit boards and their circuit components for shielding against EMI caused by the electromagnetic signals being transmitted and/or received by the device for wireless communications. 
   In certain embodiments, EMI shields may be provided on or within portions of the device about one or more of the circuit boards. For example, each of side portions  34  and base portion  36  of mating component  30  can be made by, coated with, or attached to an EMI shield or EMI shielding material. Furthermore, each of side portions  44  of mating component  40  can similarly be equipped with an EMI shield or EMI shielding material. Moreover, second side  17  of circuit board  18  can similarly be equipped with an EMI shield or EMI shielding material (see, e.g., EMI shield or EMI shielding material  70  of  FIGS. 5 and 6 ). 
   Therefore, when boards  16  and  18  are held in their stacked and mated relationship (see, e.g.,  FIG. 6 ), electrical circuit components  20  of circuit boards  16  and/or  18  may be partially or completely encapsulated by one or more EMI shields or EMI shielding materials  70 . One or more of these EMI shields  70  of device  10  can protect circuit components  20  of both circuit boards  16  and  18  rather than being dedicated to shielding a particular board of the device. This encapsulation of components  20  of mated circuit boards  16  and  18  by one or more shared EMI shields  70  can further reduce the space within device  10  consumed by the circuit board stack. 
   While the embodiments of  FIGS. 1-7  illustrate circuit board stacks that have substantially the same size as the housing of the device (e.g., housing  14  of  FIGS. 1 ,  6 , and  7 ), the total space consumed by two or more stacked circuit boards may alternatively only take up a fraction of the space provided by the housing. For example, as shown in  FIG. 8 , a device  10 ″ can be provided that may be substantially the same as device  10  or  10 ′, but whose mated stack of circuit boards  16  and  18  take up only a fraction of the space provided by housing  14 . 
   In certain embodiments, the stacked circuit boards can be significantly spaced from certain other components of the device. For example, as shown in  FIG. 8 , the mated stack of circuit boards  16  and  18  can be spaced from antenna I/O component  12 C by a distance I. This distance may help mitigate any potential EMI involving the electromagnetic signals encapsulated between the mated circuit boards and the electromagnetic signals being transmitted and/or received by the I/O component for wireless communications. 
   Furthermore, while the embodiments of  FIGS. 1-8  illustrate circuit boards having cross-sectional shapes that are substantially rectangular, the cross-sections of the boards may have any shape (e.g., circular or polygonal). Moreover, the shapes of each of any two circuit boards to be mated may vary from one another (e.g., circuit board  16  may be oval and circuit board  18  may be trapezoidal), as long as they can be stacked by appropriately sized and shaped mating components. 
   Additionally, while the embodiments of  FIGS. 1-8  illustrate mated stacks of two circuit boards, various other numbers of circuit boards may be mated and stacked. In one embodiment, a third circuit board can be mated on top of or placed adjacent to two other stacked and mated circuit boards. In an alternative embodiment, a first mated stack of two circuit boards may be mated on top of or adjacent to a second mated stack of two other circuit boards. 
   While there have been described electronic devices with circuit boards held in a mated stack, it is to be understood that many changes may be made therein without departing from the spirit and scope of the present invention. It will also be understood that various directional and orientational terms such as “horizontal” and “vertical,” “top” and “bottom” and “side,” “length” and “width” and “height” and “depth” and “thickness,” “upper” and “lower,” and the like are used herein only for convenience, and that no fixed or absolute directional or orientational limitations are intended by the use of these words. For example, the devices of this invention, as well as their individual components, can have any desired orientation. If reoriented, different directional or orientational terms may need to be used in their description, but that will not alter their fundamental nature as within the scope and spirit of this invention. Moreover, an electronic device constructed in accordance with the principles of the present invention may be of any suitable three-dimensional shape, including, but not limited to, a sphere, cone, octahedron, or combination thereof, rather than a hexahedron, as illustrated by device  10  of  FIGS. 1-6 . Those skilled in the art will appreciate that the invention can be practiced by other than the described embodiments, which are presented for purposes of illustration rather than of limitation, and the invention is limited only by the claims which follow.

Metadata:
Filing Date: 20070105
Publication Date: 20100601
Grant Date: 20100601
Priority Date: 20070105
Inventors: WANG ERIK L.
SANGUNIETTI LOUIE
Assignee: APPLE INC
CPC Classifications: [{"code": "H05K9/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K7/1417", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/144", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K2201/2018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/042", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10371", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K7/1417", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/144", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/18", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/10371", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K2201/2018", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K9/005", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/042", "inventive": false, "first": false, "tree": "[]"}]
Family ID: 39594061