PATENT DOCUMENT

Publication Number: US-8659906-B2
Application Number: US-201213442801-A
Country: US
Kind Code: B2

Title: Printed circuit board

Abstract:
A methodology for connecting device components with circuitry located at different levels and orientations relative to one another is described. First circuitry can be located on a multi-plane rigid circuit board where the multi-plane rigid circuit board can include at least one flexible member sharing a common substrate with the multi-plane rigid circuit board that extends from a body portion of the multi-plane rigid circuit board. The flexible member can include traces used to convey power and/or data and an interface coupled to the power and/or data traces. The flexible member can be deflected or twisted to connect first circuitry on the body portion of the multi-plane rigid circuit board to second circuitry associated with another device component.

Claims:
What is claimed is: 
     
       1. A printed circuit board comprising:
 a body portion of the printed circuit board; 
 a flexible portion of the printed circuit board that extends from the body portion of the printed circuit board, comprising a plurality of traces; and 
 an end portion of the printed circuit board including an interface to the plurality of traces, wherein the flexible portion is proximately located in a first plane at a first depth level within an enclosure, wherein the body portion of the printed circuit board is proximately located in a second plane at a second depth level within the enclosure, wherein the plurality of traces includes thicker traces and thinner traces and wherein the thicker traces are located in a first region of the flexible portion that is near a side edge of the flexible portion, wherein the thinner traces are located in a second region of the flexible portion that is farther from the side edge of the flexible portion than the first region, wherein the first region of the flexible portion is devoid of thinner traces and the second region of the flexible portion is devoid of thicker traces. 
 
     
     
       2. The printed circuit board as recited in  claim 1 , wherein the printed circuit board is secured by a first fastener placed across the printed circuit board proximate to where the flexible portion of the printed circuit board extends from the body portion of the printed circuit board and is secured by a second fastener placed across the printed circuit board proximate to an end of the flexible portion of the printed circuit board. 
     
     
       3. The printed circuit board of  claim 2  wherein the first fastener includes a rounded surface configured to increase a bending radius of the printed circuit board proximate to the first fastener. 
     
     
       4. The printed circuit board of  claim 3  wherein the first fastener and the second fastener are configured to concentrate bending stress in an area of the printed circuit board between the two fasteners. 
     
     
       5. A printed circuit board, comprising:
 a body portion of the printed circuit board; 
 a flexible portion of the printed circuit board, comprising a plurality of traces and an end portion of the printed circuit board including an interface to the plurality of traces, wherein the flexible portion is proximately located in a first plane at a first depth level within an enclosure, wherein the body portion of the printed circuit board is proximately located in a second plane at a second depth level within the enclosure, wherein the plurality of traces includes thicker traces and thinner traces, wherein the thicker traces are located closer to a side edge of the flexible portion than the thinner traces; and 
 a second circuit board secured within the enclosure and couple to the interface on the end portion of the printed circuit board such that power and data are communicated between the second circuit board and a main logic board via the plurality of traces on the flexible portion of the printed circuit board. 
 
     
     
       6. The printed circuit board as recited in  claim 5 , wherein the second plane is rotated at an angle relative to the first plane. 
     
     
       7. The printed circuit board as recited in  claim 6 , wherein the printed circuit board and the main logic board share a common substrate. 
     
     
       8. A multi-plane printed circuit board for use in computing device, comprising:
 an integrally formed portion, comprising a rigid body portion and a flexible portion integrally formed with the rigid body portion, wherein a free end of the flexible portion is arranged to be deflected and rotated as needed and secured at a location that is displaced in a different plane from the rigid body portion of the multi-plane rigid PCB; and 
 an interface at the free end of the flexible portion, the interface on the free end of the flexible portion suitable for being coupled to another printed circuit board in place of a flexible cable. 
 
     
     
       9. The multi-plane PCB as recited in  claim 8 , further comprising:
 a plurality of traces organized in layers comprising a first layer of traces and a second layer of traces that experience stress concurrently. 
 
     
     
       10. The multi-plane PCB as recited in  claim 9 , wherein the first of traces in the flexible portion located at a bottom part of the flexible portion of the multi-plane PCB experiences a tensile force when the free end of the flexible portion is bent in an up-ward direction. 
     
     
       11. The multi-plane PCB as recited in  claim 10 , wherein the second layer of traces in the flexible portion located at a top part of the flexible portion of the multi-plane PCB experiences a compressive force when the free end of the flexible portion is bent in the up-ward direction. 
     
     
       12. The multi-plane PCB as recited in  claim 11 , wherein the compressive force at the top part of the upwardly bent multi-plane PCB and the tensile force at the bottom part of the upwardly bent PCB are balanced at a neutral axis of the multi-plane PCB. 
     
     
       13. The multi-planned PCB as recited in  claim 12 , wherein the location of the neutral axis of the multi-plane PCB is based upon a location, number, and thickness of the first and second plurality of traces. 
     
     
       14. The multi-plane PCB an recited in  claim 13 , wherein the plurality of traces in a high stress portion of the multi-plane PCB are thick traces. 
     
     
       15. The multi-plane PCB as recited in  claim 13 , wherein the plurality of traces in a low stress portion of the multi-plane PCB are thin traces. 
     
     
       16. The multi-plane PCB as recited in  claim 8 , further comprising:
 a stress isolator, the stress isolator arranged to reduce an amount of stress in the multi-plane PCB. 
 
     
     
       17. The multi-plane PCB as recited in  claim 16 , wherein the stress isolator is configured as a fastener. 
     
     
       18. The multi-plane PCB as recited in claim wherein the flexible bed portion comprises a plurality of traces including thicker traces and thinner traces and wherein at least some of the thicker traces are routed across areas on the flexible portion with stress values that are higher than the stress values where at least some of the thinner traces are routed on the flexible portion. 
     
     
       19. A printed circuit board, comprising:
 a flexible portion; 
 a plurality of thicker traces in the flexible portion, wherein at least some of the thicker traces are located in one or more first regions of the flexible portion; and 
 a plurality of thinner traces in the flexible portion, wherein at least some of the thinner traces are located in one or more second regions of the flexible portion, wherein the one or more first regions of the flexible portion experiences more stress than the one or more second regions of the flexible portion. 
 
     
     
       20. The printed circuit board defined in  claim 19  wherein at least some of the thicker traces are located closer to a side edge of the flexible body portion than at least some of the thinner traces. 
     
     
       21. The printed circuit board defined in  claim 19  wherein at least some of the thicker traces are routed across areas on the flexible portion with stress values that are higher than the stress values where at least some of the thinner traces are routed on the flexible portion.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of and claims priority to U.S. application Ser. No. 13/117,016, entitled “A METHOD OF MANUFACTURING A PRINTED CIRCUIT BOARD” by McClure et al., filed on May 26, 2011 which is a divisional of and claims priority to U.S. application Ser. No. 12/694,166, entitled “PRINTED CIRCUIT BOARD” by McClure et al., filed on Jan. 26, 2010 and U.S. Pat. No. 7,995,334 issued on Aug. 9, 2011 which claims priority to U.S. Provisional Patent Application No. 61/292,739, entitled “HANDHELD COMPUTING DEVICE” by Ternus et al., filed Jan. 6, 2010, all of which are hereby incorporated by reference herein. 
     This patent application is related to and incorporates by reference in their entirety the following co-pending patent applications:
         (i) U.S. patent application Ser. No. 12/694,085, entitled “HANDHELD COMPUTING DEVICE” by Ternus et al., filed Jan. 26, 2010;   (ii) U.S. patent application Ser. No. 12/694,162, entitled “ASSEMBLY OF A DISPLAY MODULE” by McClure et al., filed Jan. 26, 2010;   (iii) U.S. patent application Ser. No. 12/694,200, entitled “COMPONENT ASSEMBLY” by McClure et al., filed Jan. 26, 2010;   (iv) U.S. patent application Ser. No. 12/694,168, entitled “DISPLAY MODULE” by McClure et al., filed Jan. 26, 2010; and   (v) U.S. patent application Ser. No. 12/694,083, entitled “EDGE BREAK DETAILS AND PROCESSING” by Sweet et al., filed Jan. 26, 2010, that is, in turn, a continuation in part of U.S. patent application Ser. No. 12/580,934, entitled “METHOD AND APPARATUS FOR POLISHING A CURVED EDGE” by Lancaster et al., filed Oct. 16, 2009, that takes priority under 35 U.S.C. §119(e) to U.S. Provisional Patent Application Ser. No. 61/249,200, entitled “COMPLEX GEOGRAPHICAL EDGE POLISHING” by Johannessen, filed Oct. 6, 2009.       

    
    
     BACKGROUND 
     1. Field of the Described Embodiments 
     The described embodiments relate generally to computing devices such as laptop computers, tablet computers, and the like. More particularly, circuit board connection schemes are described. 
     2. Description of the Related Art 
     In recent years, portable computing devices such as laptops, PDAs, media players, cellular phones, etc., have become small, light and powerful. One factor contributing to this reduction in size can be attributed to the manufacturer&#39;s ability to fabricate various components of these devices in smaller and smaller sizes while in most cases increasing the power and or operating speed of such components. The trend of smaller, lighter and powerful presents a continuing design challenge in the design of some components of the portable computing devices. 
     One design challenge associated with the portable computing device is the design of the enclosures used to house the various internal components. This design challenge generally arises from a number conflicting design goals that includes the desirability of making the enclosure lighter and thinner, the desirability of making the enclosure stronger, and making the enclosure more aesthetically pleasing. Within the enclosure, power and data connections need to be established between the various internal components with considerations of the packing efficiency and ease of assembly. 
     Typically, the portable computing device will have one or more enclosure components where each enclosure component has some external profile with a ‘thickness’ that is relatively constant. Various internal components can be distributed within the external profile of each of the enclosure components. To improve the packing efficiency, the internal components can be located at various heights within the thickness of each enclosure component. Numerous data and power connections can link the internal components. Since two internal components can be situated at different heights, the data and power connections are needed to traverse the height difference to link the two components. 
     A connection between two internal components of different heights is often accomplished using a flexible cable often referred to as “flex.” As an example, flex can be used to connect two circuit boards at different heights where each circuit board includes a connector that is compatible with connectors on each end of the flex. The use of flex requires extra connectors and more assembly steps, which increases costs. In view of the foregoing, there is a need for improved internal component connection schemes. 
     SUMMARY OF THE DESCRIBED EMBODIMENTS 
     This paper describes various embodiments that relate to systems, methods, and apparatus for enclosures for use in computing applications, such as the assembly of portable computing devices. A methodology for connecting device components with circuitry located at different levels and orientations relative to one another is described. In one embodiment, first circuitry can be located on a multi-plane rigid circuit board. The multi-plane rigid circuit board can include at least one flexible member. The flexible member can include traces used to convey power and/or data and an interface coupled to the power and/or data traces. The flexible member can be deflected or twisted to connect first circuitry on the multi-plane rigid circuit board to second circuitry associated with another device component. The flexible member can be formed as an integral component of the multi-plane rigid circuit board, i.e., the flexible member and the multi-plane rigid circuit and the flexible member share a common substrate. 
     In one aspect, a first printed circuit board and an enclosure for a portable computing device can be provided. The first printed circuit board can include a flexible member extending from a body portion of the first printed circuit board. The flexible member can includes a number of traces and a free end of the flexible member can include a first interface to the traces. The first printed circuit board can be secured within an interior portion of the enclosure. A first fastener can be secured across the flexible member such that a surface of the first fastener is in contact with a side of the flexible member including the traces. A portion of the fastener can be insulated to prevent shorts from occurring across the traces. 
     The free end of the flexible member can be deflected such that the flexible member is bent along a first line near the first fastener. The free end of the flexible member can be secured using a second fastener where the flexible member is bent along a second line near the second fastener. The first and second fasteners can tend to localize stresses resulting from deflecting and/or twisting the flexible members to an area on the flexible member between the two fasteners. After it is secured, the end portion of the free end can be located at a different depth within the enclosure than the body portion of the first printed circuit board and/or at a different angular orientation to the body portion. A second circuit board including second circuitry can be connected to the first interface to allow data and power to be transmitted between the second circuit circuitry and first circuitry located on the body portion of the first circuit board via the traces on the flexible member. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The embodiments 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: 
         FIGS. 1   a  and  1   b  show a side view and a top view, respectively, of a portable computing device with three unconnected internal components in accordance with the described embodiments. 
         FIGS. 2   a  and  2   b  show a side view and a top view, respectively, of a portable computing device with three internal components shown in  FIGS. 1   a  and  1   b  connected using a multi-plane rigid circuit board in accordance with the described embodiments. 
         FIG. 3  shows a top view of a multi-plane rigid circuit board in accordance with the described embodiments. 
         FIG. 4  is a flow chart of a method of manufacturing a portable computer device using a multi-plane rigid circuit board. 
     
    
    
     DESCRIBED EMBODIMENTS 
     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 particular embodiments of the devices described herein, one or more of internal components can include a multi-plane rigid circuit board. The multi-plane rigid circuit board can include at least one flexible member. The flexible member can include traces used to convey power and/or data and an interface coupled to the power and/or data traces. The multi-plane rigid circuit board can be installed within a computing device and then a free end of the flexible member can be deflected and/or twisted and secured at a location that is above or below a level where a remaining portion of the multi-plane rigid circuit board is secured or in a different plane from the remaining portion of the multi-plane rigid circuit board. The interface on the free end of the member can be coupled to a printed circuit board such that power and/or data can be transmitted between circuitry residing on the multi-plane rigid circuit board and circuitry residing on the printed circuit board via the flexible member. In some instances, the use of multi-plane circuit board can be used to replace flex cables in the design of the portable computing device. 
     As an example, a portable computing device can have a main logic board. The portable computing device can have an enclosure and the main logic board where the main logic board is designed to reside at a certain depth within the enclosure. The main logic board can be a multi-plane rigid circuit board. Thus, the main logic board can include one or more flexible members including power and/or data traces and an interface to the power and/or data traces. The main logic board can be installed at a first level within the portable computing device and then the one or more flexible members can be secured at locations above or below the level of the main logic board or in a different plane than the main logic board. The traces on the flexible member can be used to transmit power and/or data between the main logic board and another component associated with the portable computing device, such as but not limited to a SIM card, a wireless interface (e.g., an antenna), a multi-pin data connector, a multi-pin power connector or a combination multi-pin data and power connector. 
     The circuitry associated with the additional component can be located in a plane that is above or below a body portion of the main logic board and/or is not parallel to the main logic board. The flexible member on the main logic board can be used to traverse the depth change as well as an angle change between the body portion of the main logic board and a location of the circuitry associated with the additional component. In general, the methodology used herein can be used to connect two different circuitry components located in planes of a different depth where the planes can be at an angle relative to one another. The methodology can be applied within a computing device, portable or not, and is not limited to the example of a connection between a main logic board and other circuitry within a computing device. 
     The use of multi-plane rigid circuit boards is described with respect to the following  FIGS. 1   a - 4 .  FIGS. 1   a  and  1   b  show a side view and a top view, respectively, of a computing device with three unconnected internal components where one of the components is a multi-plane rigid circuit board with two flexible members.  FIGS. 2   a  and  2   b  show a side view and a top view, respectively, of a portable computing device with three internal components shown in  FIGS. 1   a  and  1   b  connected using the two flexible members of the multi-plane rigid circuit board in accordance with the described embodiments.  FIG. 3  shows a top view of a multi-plane rigid circuit board with three different flexible members.  FIG. 4  is a flow chart of a method of manufacturing a portable computer device incorporating a multi-plane rigid circuit board. 
       FIGS. 1   a  and  1   b  show a side view and a top view, respectively, of a portable computing device  100  with three unconnected internal components in accordance with the described embodiments. The portable computing device  100  includes an enclosure  102 . The external profile and the internal profile of the enclosure  102  is that of a rectangular box. The enclosure  102  can have a thickness, where different thickness heights are denoted by the ‘z’ dimension  110 . A length and width of the enclosure  102  can be denoted by the x and y dimensions,  116  and  118 , respectively. 
     The rectangular profile including its relative thickness is provided for illustrative purposes only. In various embodiments, the external profile can include various surfaces, such as rounded surfaces that differ from a pure rectangular profile. Further, the internal profile can be shaped very differently from the external profile. The internal profile can have steps and curved surfaces that vary from location to location throughout the interior of the computing device where a nominal thickness between the external and internal profiles can vary throughout the enclosure. 
     Various devices and their associated components can be distributed throughout the enclosure and linked together, such as but not limited to antenna components, external data and power interfaces, mechanical button components, audio components, display components, touch screen components, processor and memory components and battery components. Typically, devices and their associated components include printed circuit boards (PCBs) with associated connectors that allow the components to be linked to one another via a connection scheme of some type. The connection scheme can allow power to be delivered to a component, if required, and can allow for communication between various components to occur. 
     In  FIGS. 1   a  and  1   b , three PCBs, such as,  104 ,  106  and  108 , are shown. The PCBs,  104 ,  106  and  108 , are shown unconnected to one another. In one embodiment, PCB  104  is a main logic board and includes a CPU component  112 . The PCBs,  104 ,  106  and  108 , can be constructed from a material, such as a plastic, and other suitable materials useful with printed circuit boards. 
     In  FIG. 1   a , the PCBs,  104 ,  106  and  108  are located at different heights  110  within the enclosure  102 . The first PCB  104  is located at a first height. The second PCB  106  and third PCB  108  are located at height above the first PCB  104 . Further, the height of PCB  106  changes along the y dimension  118  while the heights of PCB  104  and PCB  108  are constant in this direction, i.e., the boards lie on a constant z-plane. 
     Each of the PCBs,  104 ,  106  and  108  can be secured or anchored to an underlying support structure that is coupled to the enclosure  102 . The underlying support structure is generically illustrated as box  101 . The support structure can include frames, fasteners and posts that can vary depending on the design of the portable computing device  100 . 
     In  FIG. 1   b , prior to the connections being formed between the boards, the PCBs,  104 ,  106  and  108  can overlap with one another in the x,  116 , and y,  118 , dimensions. PCB  104  can include a center portion with two rectangular flexible members,  124  and  126 , extending from the center portion of the PCB  104 . Thus, in this example, PCB  104  can be multi-plane rigid circuit board. In the unconnected state, a portion of member  124  can be disposed below and can overlap with PCB  106  and a portion of member  126  can be disposed below and can overlap with PCB  108  as shown in the top view of  FIG. 1   b.    
     The flexible members  124  and  126  can be made of the same material as the remaining portion of the multi-plane rigid circuit board  104  where board  104  can be a single integral piece including integral traces, i.e., the members  124  and  126  are not formed separately and then coupled to the board  104 . In some embodiments, the material composition used in  104  can be adjusted to make the entire board  104  and hence the flexible members  124  and  126  more flexible. In other embodiments, the material composition of the flexible members  124  and  126  and the area proximate to where the flexible members  124  and  126  extend from the board  104  can be adjusted to improve flexibility of the members and the board in these areas. Thus, portions of the board  104  can be more rigid than other portions of the board  104 . 
     Member  124  includes an interface  128   b  to the power and/or data traces  120  that generally aligns with an interface  128   a  to circuitry on PCB  106 . Member  126  includes an interface  130   b  to the power and data traces  122  that generally aligns with an interface  130   b  to circuitry on PCB  108 . The interface pairs, ( 128   a ,  128   b ) and ( 130   a ,  130   b ) are shown slightly off set from one another because they are unconnected. The deflection of the flexible members  124  and  126  in the z-dimension  110  to enable a connected state can shorten their length in the x,  116 , and y,  118 , dimensions respectively. When deflected, the interface pairs can be more closely aligned, i.e., less off-set in the x-y plane as is shown and described with respect to  FIGS. 2   a  and  2   b . Possible deflection distances in the z-dimension can be up to 15 mm or greater. 
     As described above, members,  124  and  126 , of PCB  104  can include traces,  120  and  122 , respectively. The traces form conductive paths on the PCB  104  and allow power and/or data to be transmitted between components on the PCB  104 . The traces can be laid down when the over-all circuitry of PCB  104  is formed. Typically, the traces are a thin line of metal, such as copper. The thickness of each trace can vary from trace. For instance, a trace that carries power can be thicker than a trace that carries data. 
     In general, one or more traces can be located on the members  124  and  126  and embodiments are not limited to the three traces shown in the Figures. Further, the number of traces can vary from member to member. For instance, member  124  can include traces that lead to a 30 pin connector and thus, can have 30 traces when all of the pins are connected. Member  126  can include traces that lead to a 10 pin connector and thus, can have 10 traces when all of the pins are connected. Seventy and one hundred pin connectors are available for certain devices and members  124  and  126  can be configured with the number of traces necessary to provide connections to these types of connectors. The number traces can vary according to the devices that are being connected, such as but not limited to a main logic board and a Sim card or an external data connector. 
       FIGS. 2   a  and  2   b  show a side view and a top view, respectively, of a portable computing device with three internal components shown in  FIGS. 1   a  and  1   b  connected using the two flexible members,  124  and  126 , of the multi-plane rigid circuit board in accordance with the described embodiments. Referring to  FIG. 2   b , in a connected state, an end of the member  124  is deflected in the z dimension  110  and twisted at an angle  132  such that the end of the member is secured in an orientation that is proximately parallel to a bottom surface of board  106 . The amount of twist along the member  124  varies to allow it to reach angle  132  at its end. Thus, traces  120  on the member  124  are also bent and twisted through a range of angles until the angle  132  is reached. 
     The member  126  is bent at an angle  134  relative to the z-plane of the remaining portion of board  104 . An end portion of member  126  is bent through a second angle  135  such that the end portion is parallel to a portion of the surface of board  108 . Thus, the traces on  122  on member  126  are also bent through these two angles. 
     In this example, board  108  and the remaining portion of board  104  are proximately parallel. Thus, the angles  134  and  135  are proximately equal. In other embodiments, the angles  134  and  135  can be different. For instance, board  108  can be rotated up or down through an axis in the x dimension as indicated by the arrows in the  FIG. 2   a , such that angle  135  is greater than or less than angle  134  (depending on the direction and angle of rotation) to enable the end portion of member  126  to be parallel to a portion of surface  108 . 
     Between the bend points at which angles  134  and  135  are shown, the member  126  is shown is being straight. This orientation is provided for illustrative purposes. Between the bend points, the member  126  can be bowed up or bowed down and possibly slightly twisted if board  104  and board  106  are not parallel to enable proper alignment of an interface on the member  126  and an interface on board  108 . Thus, the orientation is not limited to being in a straight orientation as shown in the figure. 
     In a connected orientation, interface  128   a  is on a lower surface of board  106  and interface  128   b  is on a top surface of flexible member  124 . In various embodiments, during assembly, a body portion of board  104  and the end of member  124  can be secured in their respective orientations. The body portion of board  104  can be secured first and then the end of member  124  can be secured or vice versa or both can be secured simultaneously. After the end of member  124  is secured (the remaining portion of board  104  may or may not be secured at this point), the board  106  can be secured such that a successful connection is made between the interfaces  128   a  and  128   b . In another embodiment, the board  106  can be secured first and then the end of member  124  can be slid under board  106  to form a connection between the boards. After a connection is formed, the member  124  can be secured in place. 
     In another example, in a connected orientation, interface  130   b  is on an underside surface of the end of flexible member  126  and interface  130   a  is on a top surface of board  108 . In various embodiments, during assembly, end portion of member  126  can be secured in place and then board  108  can be slid underneath to form a connection. Alternatively, board  108  can be secured in place and then the end portion of member  126  can be placed over the board  108 , connected and then secured. 
     Referring to  FIG. 2   b , proximate to bend locations, fasteners can be used. For example, fasteners,  125   a  and  125   b , are shown securing member  124  and fasteners  125   c  and  125   d  are shown securing member  126 . The fasteners  125   a - 125   d  can include holes and posts, such as  127 , for allowing a fastener, such as a screw, to be placed through the fastener. A portion of the fastener can be in contact with the traces, such as traces  120  and  122 . When a portion of the fastener is in contact with the traces, it can be composed of a non-conductive material, such as plastic, to prevent shorts across the traces. A remaining portion of the fastener can be comprised of another material if desired, such as a metal. For instance a piece of metal with the mounting holes can be secured over a piece of plastic in contact with the traces. 
     The fasteners  125   a  and  125   b  can be placed in contact with the flexible members to define regions of bending on the flexible member  124 . Similarly, fasteners  125   a  and  125   b  can be placed in contact with flexible member  126  to define region of bending. When the fasteners  125   a  and  125   b  or  125   c  and  125   d  are secured, most of the bending stress can be confined on the region of the flexible members,  124  or  126 , between the fasteners such that stress is not transferred to the remaining portion of board  104  or to the areas where interfaces  128   a / 128   b  and  130   a / 130   b  are connected. Using fasteners in this way can prevent damage to board components, such as components on board  104  and prevent the connections between boards  104 - 106  and  104 - 108  from coming loose. Thus, the fasteners can be considered “stress isolators,” in that the fasteners tend to localize or isolate the stress to particular areas, such as to a particular area of the flexible member. 
     In a particular embodiment, a surface of the portion the fasteners, such as  125   a ,  125   b ,  125   c  and  125   d , can be rounded. The rounded surface can provide a radius of curvature for the bending of one of the members, such as  124  and  126 , and prevent a sharp edge from pressing into the traces and possibly damaging the traces. Further, the radius of curvature can possibly reduce stresses on the traces that occur as result of bending. For example, an underside of fastener  125   c  can be rounded to provide a radius of curvature for the bending of member  126  through angle  134 . The boards  108  can also be rounded for a similar purpose. For instance, an edge of board  108  can be rounded to provide a radius of curvature for the bending of the free end of member  126  through angle  135 . 
     In particular embodiments, the traces on the flexible member can be organized in layers. For example, a number of trace layers, such as 10 trace layers, can be provided from near the top surface of flexible member  124  to a bottom surface of flexible member  124 . One or more traces can be located in the in-depth layers. The trace layers can be populated when a multi-plane rigid circuit board, such as  104  is formed. 
     When the flexible member  124  is bent, a portion of the member  124  can be placed in compression and a portion can be placed in tension. For example, when member  126  is bent upwards near fastener  125   c , a top portion of the member  126  is placed in compression and a lower portion of the member  126  is placed in tension. Within the member  126 , such as near a center layer, the compressive and tensile forces are proximately balanced. In a bending beam, the layer where the forces are balanced is often referred to as the neutral axis. Similarly, in twisting, there can be regions that are compressed or stretched more than other areas and regions where forces are balanced. Areas where compressive and tensile forces are balanced or nearly balanced can be good locations to locate traces within a flexible member, such as members  124  and  126 . 
     Referring to  FIG. 2   b , a side view across member  124  is shown to expose a number of layers between the top and bottom surface of member  124 . A neutral axis  124   c  where compressive and tensile forces are proximately balanced is depicted. The neutral axis  124   c  is provided for the purposes of discussion only and is not meant to be an accurate representation of the location of the neutral axis. 
     On the portion of the secured members between the fasteners, such as between fasteners,  125   a  and  125   b , on flexible member  124 , more stress can be located near the top and bottom edge layers of the flexible member, such as in location  124   b  near the bottom surface, as compared to the center area  124   a  of the flexible member. The traces arranged on the member  124 , such as traces  120   a  and  120   b , can be of different thicknesses. For instance, a trace carrying power can be thicker than a trace carrying data. The thicker traces can tolerate more stress. During design of a multi-plane rigid circuit board, such as  104 , the traces on the flexible members can be arranged such that thicker traces are located in regions anticipated to experience high stress and thinner traces can be located in regions anticipated to experience lower stresses as a result of bending. For example, the stresses on member  124  can be higher at the edge  124   b  than at the center  124   a  under bending. If trace  120   a  is thicker than  120   b , trace  120   a  can be placed closer to the edge  124   b  than trace  120   b.    
     The shape of a flexible member can be altered if it is does not have a big enough area of low stress to accommodate all of the traces that require a low stress level. For instance, if there were too many traces to fit in a center area  124   a  of member  124  that will experience low stress upon bending, then width of member  124  can be widened to increase an area of low stress near the center  124   a . Then, additional traces can be routed through the low stress area. As another example, the thickness of the flexible member, such as  124  or  126 , can be increased to possibly increase a number of suitable layers in the low stress areas. 
     As a result of variable bending and twisting along a length of a flexible member. The areas of low stress can vary along a length of the member. For example, as a result of twisting at one end of member  124  the area of low stress can be closer to a particular edge or surface than at the other end. The traces can be designed to follow a path of low stress along the member. Thus, traces do not necessarily have to follow a straight path parallel to the edge of the flexible member along the length of the member. For instance, the traces can follow a curved path along the length of a flexible member. In the design process, stress distributions for various deflections of a flexible member can be determined and these stress distributions can be used to develop trace paths along the flexible member. 
     In particular embodiments, because of the stress between the fasteners on a flexible member, it may be desirable not to place any circuitry components other than the traces in between the fasteners. In other embodiments, if the stress is not too great it can be possible to place additional circuitry components in this area. To allow the fasteners to apply a force evenly across the flexible members and because the region next to the fasteners experiences high bending stresses, it may be desirable not to locate circuitry other than traces proximate to where the fasteners are secured and particularly beneath the fasteners. 
       FIG. 3  shows a top view of a multi-plane rigid circuit board  136  in accordance with the described embodiments. The board  136  includes three flexible members,  138 ,  142  and  146 . Two of the flexible members  142  and  146  extend from a body portion  137  of the board  136 . A third member  138  is within the body portion  137 . Each flexible member, such as  138 ,  142  and  146  can be associated with multiple bend lines and include an end portion located near the free end of the flexible member. Bend lines  140   a  and  140   b  are depicted for member  138  and bend lines  144   a  and  144   b  are depicted for member  142 . 
     An end portion  143 , below bend line  140   b , on the free end of member  138  is shown. The end portion  143  can include an interface that connects to power and/or data traces located on the member  138 . The free end of member  138  can be deflected up or down as well as twisted and secured at another location. Then, the interface on the free end can be coupled to other circuitry, such as another board, to establish power and data connections. 
     A bend line does not have to be necessary located at the intersection between the flexible member and the body portion  137 . In various embodiments, the bend line can be located a distance away from the intersection. For example, bend line  144   b  is located on flexible member  142  above the intersection between the member  142  and the body portion  137 . 
     Two bend lines are depicted for members  138  and  142 . In one embodiment, a flexible member, such as  138 ,  142  or  146  can be bent along only a single bend line. In other embodiments, a flexible member can be bent at more than two locations along the member. The bend lines that are generally perpendicular to an edge of the flexible member are depicted. Nevertheless, in further embodiments, one or more diagonal bend lines, such as bend line  145  can be used. Finally, although flexible members have been shown as rectangles of a constant width other shapes are possible in various embodiments. For instance, member  146  includes a widened end portion  148  where the width of the portion  148  is wider than the rest of the body of the member  146 . In other examples, the flexible members can have curved or tapered portions (not shown). 
       FIG. 4  is a flow chart of a method  149  of manufacturing a computer device, such as portable computing device, using a multi-plane rigid circuit board. In  150 , the bend line locations and stress distributions across of a flexible member of a first circuit board can be determined. The first printed circuit board can be a multi-plane rigid circuit board as previously described. In one embodiment, the first printed circuit board can be a main logic board for the portable computing device. In  152 , the trace locations on a flexible member of a first printed board can be determined. The trace locations can be arranged on the flexible member based upon the determined stress locations. For instance, thicker traces can be placed in high stress areas and thinner traces can be placed in low stress areas. If the low stress areas are not large enough to accommodate all of the thin trace lines then the flexible member can be resized and steps  150  and  152  can be repeated. Next, the first circuit board can be manufactured. In one embodiment, the first circuit board can include markings on the flexible member indicating proximate locations where bending is to take place on the flexible member during assembly. 
     In  154 , the first printed circuit board can be secured to a support structure associated with an enclosure of the portable computing device. In  156 , a first stress isolator, which can be a fastener, can be secured across a flexible member associated with the first printed circuit board proximate to a first bend line associated with the flexible member. In  158 , a free end of the flexible member can be deflected and/or twisted such that an end portion of the flexible member is aligned in a preferred orientation. The preferred orientation of the flexible member can be at different level and/or in a different planar orientation than a portion of the first printed circuit board. 
     In  160 , a second stress isolator, which can be a fastener, can be secured across the flexible member proximate to a second bend line to fix the end of the flexible member in the preferred orientation. If necessary, additional fasteners can be used to secure the end portion in the preferred orientation. In  162 , a first connection interface on the end the portion of the member in the preferred orientation can be secured to a second connection interface on a second printed circuit board. Via traces on the flexible member, power and/or data can be transferred between the first circuit board and the second circuit board. In a particular embodiment, the first circuit board can be a main logic board and the second circuit board can be associated with one of a an external pin connector interface, a Sim Card, an antenna, a memory unit, a display, an audio device, a touch screen, a button or some other type of mechanical controller (e.g., a volume slider or volume disc). 
     The advantages of the invention are numerous. Different aspects, embodiments or implementations may yield one or more of the following advantages. The connection schemes described herein allows for a first circuit board with a flexible member. The flexible member can include traces for carrying power and/or data and an interface to the power and/or data traces. A flexible member can be deflected and secured at a first level within the portable computing device and a remaining portion of the first circuit board can be secured at a second level. Via the interface on the flexible member, a second circuit board secured at the first level can be coupled to the first circuit board. One advantage is that power and/or data connections between two circuit boards secured within a portable device at different levels can be linked without the use of flex. The many features and advantages of the present invention are apparent from the written description and, thus, it is intended by the appended claims to cover all such features and advantages of the invention. Further, since numerous modifications and changes will readily occur to those skilled in the art, the invention should not be limited to the exact construction and operation as illustrated and described. Hence, all suitable modifications and equivalents may be resorted to as falling within the scope of the invention.

Metadata:
Filing Date: 20120409
Publication Date: 20140225
Grant Date: 20140225
Priority Date: 20100106
Inventors: MCCLURE STEPHEN R.
BANKO JOSHUA D.
TERNUS JOHN P.
Assignee: APPLE INC
CPC Classifications: [{"code": "Y10T29/49135", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1613", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/147", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49135", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1633", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0277", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49126", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49169", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0252", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49124", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49155", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1613", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49169", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/4914", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49128", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0281", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/118", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/4914", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/118", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/09727", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49155", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K3/326", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/0277", "inventive": true, "first": true, "tree": "[]"}, {"code": "Y10T29/49128", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K5/0017", "inventive": false, "first": false, "tree": "[]"}, {"code": "Y10T29/49126", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}, {"code": "Y10T29/49124", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0252", "inventive": false, "first": false, "tree": "[]"}, {"code": "H05K1/0281", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1656", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K2201/09727", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04M1/0266", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1643", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/1613", "inventive": true, "first": true, "tree": "[]"}, {"code": "H05K1/147", "inventive": false, "first": false, "tree": "[]"}, {"code": "G06F1/1626", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/118", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04M1/0277", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/11", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/02", "inventive": true, "first": false, "tree": "[]"}, {"code": "H05K1/14", "inventive": true, "first": false, "tree": "[]"}, {"code": "G06F1/18", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 47215981