(12) Unlted States Patent
`(10) Patent No.:
`US 8,270,915 B2
`
`Sanford et al.
`(45) Date of Patent:
`Sep. 18, 2012
`
`USOO8270915B2
`
`(75)
`
`(54) ANTENNA AND BUTTON ASSEMBLY FOR
`WIRELESS DEVICES
`Inventors: Emery A. Sanford, San Francisco, CA
`(US); Zhijun Zhang, Santa Clara, CA
`.
`‘
`(CUASL Evans Hankey’ san FranCISCO’
`(U )
`.
`.
`(73) Ass1gnee: Apple Inc., Cupertlno, CA (US)
`
`~~~~~~~~~~~~~~~~~~~ 343/702
`
`l.
`
`18301113th all
`21/388;
`2,222,221; 31 *
`war eta .
`5
`a
`2/2005 Chang
`6,859,179 B2
`t
`2/2006 H
`6,995,716 B2
`4/2006 W33? 33
`7,023,387 132
`12/2009 Caballero et a1.
`7,639,187 B2
`11/2002 Kasuya et al.
`2002/0163472 A1
`8/2003 Bae ............................... 455/568
`2003/0157972 A1*
`11/2003 Sward et al.
`2003/0210199 A1
`2004/0203488 A1* 10/2004 Sullivan et al.
`.............. 455/901
`2005/0243015 A1
`11/2005 Kfoury et al.
`2007/0109204 A1 *
`5/2007 Phillips et al.
`
`................ 343/702
`
`( * ) Notice:
`
`Subject to any disclaimer, the term of this
`patent is extended or adjusted under 35
`U.S.C. 15403) by 1258 days.
`
`FOREIGN PATENT DOCUMENTS
`
`W0
`W0
`
`W0 02/087011
`WO 99/41801
`
`10/2002
`8/1999
`
`(21) Appl. No.: 11/651,094
`
`* cited by examiner
`
`(22)
`
`Filed:
`
`Jan. 6, 2007
`
`Primary Examiner 7 Lana N Le
`Assistant Examiner 7 Hsin-Chun Liao
`
`(65)
`
`Prior Publication Data
`
`US 2008/0166004 A1
`
`Jul. 10, 2008
`
`(51)
`
`(56)
`
`Int Cl
`(2006.01)
`H04B 1/38
`(52) US. Cl.
`....... 455/903. 455/902. 343/904. 381/375
`(58) Field of Classification Search
`5
`:155/90 2
`455/90 3343/904 381/375
`lication file for com lete search histo
`p
`References Cited
`U.S. PATENT DOCUMENTS
`
`See a
`
`pp
`
`ry.
`
`2,931,115 A *
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`5,657,969 A
`5,710,987 A *
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`6,046,699 A
`6,097,339 A
`6,099,482 A *
`6,266,017 B1
`6,509,876 B1
`
`.................. 353/116
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`4/1960 Pester et al.
`8/1995 Wright et al.
`8/1997 Bivens
`1/1998 Paulick ...................... 455/5757
`5/1998 Rudisill
`4/2000 Elliott et al.
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`8/2000 Brune et al.
`.................. 600/549
`7/2001 Aldous
`1/2003 Jones et 31.
`
`(74) Allorneyflgenl, orFirm 7 Treyz Law Group; G.Victor
`T
`' D 'd C. K 11
`reyz’ a“
`e Ogg
`
`ABSTRACT
`(57)
`An antenna and button assembly is provided for a compact
`portable Wireless dev1ce such as a Wireless headset for a
`handheld electronic device. An antenna structure is mounted
`within a button structure. The button structure includes a
`switch actuation member that extends past the antenna struc-
`ture and into engagement with a switch. The switch actuation
`member may reciprocate within the button structure. A user
`may press upon an exposed end of the switch actuation mem-
`ber to operate the switch. The switch may be used to control
`the application of power to the compact portable wireless
`device or to perform other suitable functions. The button
`structure may be formed using dielectric materials such as
`plastic. By forming the button structure from dielectric, clear-
`ance is provided between the antenna structure and conduc-
`tive portions of the compact portable wireless device so that
`the antenna of the compact wireless device operates properly.
`
`16 Claims, 9 Drawing Sheets
`
`
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`APPLE 1006
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`APPLE 1006
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`1
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`US. Patent
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`Sep. 18, 2012
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`Sheet 1 019
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`US 8,270,915 B2
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`2
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`U.S. Patent
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`Sep. 18, 2012
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`Sheet 2 of 9
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`US. Patent
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`Sep. 18, 2012
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`Sheet 3 of9
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`US. Patent
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`Sheet 4 of9
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`US. Patent
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`Sep. 18, 2012
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`Sheet 5 of9
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`FIG.5
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`US. Patent
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`Sep. 18, 2012
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`Sheet 6 of9
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`FIG.6
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`Sep. 18, 2012
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`Sheet 7 of9
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`FIG.7
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`US. Patent
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`Sep. 18, 2012
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`Sheet 8 of9
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`US 8,270,915 B2
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`FIG.8
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`9
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`US. Patent
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`Sep. 18, 2012
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`Sheet 9 of9
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`US 8,270,915 B2
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`100
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`FIG.9
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`US 8,270,915 B2
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`1
`ANTENNA AND BUTTON ASSEMBLY FOR
`WIRELESS DEVICES
`
`BACKGROUND
`
`This invention relates generally to wireless communica-
`tions devices, and more particularly, to antenna and button
`structures for wireless communications devices.
`
`As integrated circuit technology advances, it is becoming
`feasible to construct portable wireless devices with small
`form factors. Examples of portable wireless devices include
`mobile telephones, wireless headsets, digital cameras with
`wireless
`capabilities,
`remote controls, wristwatch-type
`devices, music players with wireless functions, and handheld
`computers. Devices such as these are often small enough to be
`held in the hand and may sometimes be referred to as hand-
`held electronic devices. Larger portable wireless devices
`include laptop computers.
`Portable electronic devices sometimes use antennas to
`
`transmit and receive radio-frequency signals. For example,
`wireless Bluetooth headsets have antennas for communicat-
`
`ing with cellular telephones.
`For proper antenna operation, an antenna resonating ele-
`ment in a portable wireless device is generally placed at a
`suitable distance from the conductive structures in the device.
`
`Sometimes antennas are mounted externally. This type of
`arrangement is used, for example, in certain cellular tele-
`phone whip antenna arrangements. When a more compact
`arrangement is needed, an antenna resonating element may be
`mounted on a printed circuit board in a device. However, to
`ensure satisfactory performance, it is generally necessary to
`locate the resonating element on a special portion of the
`circuit board that has been maintained free of electrical com-
`
`ponents. If suflicient clearance is not provided for the antenna
`resonating element in this way, the antenna may fail to operate
`properly.
`In some situations, it is not acceptable to use an external
`antenna design. Constraints such as a desire for compactness,
`light weight, and good esthetics can make external designs
`inappropriate. Similarly, antenna arrangements based on cir-
`cuit boards in which a large clearance is provided between an
`antenna resonating element and components mounted on the
`board may be unsatisfactory because too much board real
`estate is dedicated to providing the clearance.
`It would therefore be desirable to be able to provide
`improved compact antenna configurations for wireless com-
`munications devices.
`
`SUMMARY
`
`In accordance with the present invention, wireless commu-
`nications devices are provided. For example, a compact por-
`table wireless device such as a wireless headset may be pro-
`vided. The compact portable wireless device may have a
`button. The button may be formed substantially from dielec-
`tric such as plastic. An antenna may be formed by mounting
`an antenna resonating element on part of the button. Because
`the button is formed from dielectric, the button does not
`interfere with the proper operation ofthe antenna and helps to
`provide suitable clearance between the antenna resonating
`element and conductive structures in the compact portable
`wireless device.
`
`the button contains a
`With one suitable arrangement,
`switch such as a dome switch. The switch may be operated by
`pressing against the switch with a switch actuation member.
`The button may have a button guide structure. The button
`guide structure may have a guide channel. The guide channel
`
`2
`
`may be provided in the form of a hole through the button
`guide structure. The switch actuation member may have a
`stem that is supported and guided by the guide channel. When
`pressed by a user, the switch actuation member moves along
`the guide channel towards the switch. Raised structures such
`as ribs may be used to ensure that the switch actuation mem-
`ber reciprocates smoothly within the guide channel.
`The wireless device may have a metal housing portion and
`a dielectric housing portion. The button may be formed within
`the dielectric housing portion, so that the performance of the
`antenna is not degraded.
`The antenna resonating element may be formed from a flex
`circuit containing a strip of conductor. The flex circuit may be
`attached to the button guide structure using adhesive. The flex
`circuit may contain registration holes that mate with corre-
`sponding registration bosses. One or more of the bosses may
`serve as heat stake bosses and may be heat treated to help
`secure the flex circuit to the button guide structure.
`Further features of the invention, its nature and various
`advantages will be more apparent from the accompanying
`drawings and the following detailed description of the pre-
`ferred embodiments.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is a schematic diagram of an illustrative compact
`portable wireless device in accordance with an embodiment
`of the present invention.
`FIG. 2 is a cross-sectional side view of an illustrative
`
`compact portable wireless device using an antenna and button
`assembly in accordance with an embodiment of the present
`invention.
`
`FIG. 3 is an exploded perspective view of an antenna and
`button assembly in accordance with an embodiment of the
`present invention.
`FIG. 4 is a perspective view of an antenna and button
`assembly in which a circuit board has been mounted to a
`button guide and antenna support structure in accordance
`with an embodiment of the present invention.
`FIG. 5 is a top view of a portion of a printed circuit board
`in an antenna and button assembly in accordance with an
`embodiment of the present invention.
`FIG. 6 is a cross-sectional side view of an illustrative
`
`antenna and button assembly showing how electrical contact
`for an antenna resonating element may be made using a spring
`conductor in accordance with an embodiment of the present
`invention.
`
`FIG. 7 is a side view of an antenna and button assembly in
`accordance with an embodiment of the present invention.
`FIG. 8 is a top view of an illustrative flex circuit that
`includes a patterned antenna resonating element in accor-
`dance with an embodiment of the present invention.
`FIG. 9 is an end view of an illustrative antenna and button
`
`assembly showing how a flex circuit that includes an antenna
`resonating element may be wrapped around a button support
`in accordance with the present invention.
`
`DETAILED DESCRIPTION
`
`The present invention may apply to any suitable type of
`compact portable wireless device. Compact portable wireless
`devices that may be used with the antenna and button arrange-
`ments of the invention include cellular telephones, remote
`controls, global positioning system devices, music players,
`portable computers, wrist devices, pendant devices, head-
`phone and earpiece devices, other wearable and miniature
`devices, and hybrid devices that include the functionality of
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`US 8,270,915 B2
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`3
`two or more of these devices. With one particularly suitable
`arrangement, which is described herein as an example, the
`compact portable wireless device is a wireless headset. It is
`desirable for wireless headsets to be compact and lightweight
`and to be free of unsightly protrusions.
`An illustrative wireless headset is shown in FIG. 1. Headset
`
`device 10 may have a elongated housing 12. For esthetic
`reasons and for durability, most ofhousing 12 may be formed
`of metal or other conductive materials (as an example).
`Device 10 may use an antenna to communicate wirelessly
`with external equipment. The antenna may be enclosed in
`housing 12 in region 26. To avoid interference with the
`antenna, the portion of housing 12 in region 26 may be con-
`structed from plastic or other suitable dielectric.
`The external equipment with which device 10 may com-
`municate includes personal computers, portable computers,
`cellular telephones, music players, cellular telephones with
`music player functionality, other handheld electronic devices,
`and other suitable equipment. As an example, headset device
`10 may be a Bluetooth® headset that communicates over a
`2.4 GHZ communications band with a handheld electronic
`
`device having voice communications capabilities. An illus-
`trative Bluetooth headset arrangement of the type that may be
`used for device 10 is described in concurrently-filed com-
`monly-assigned US. patent application No. 60/879,177,
`entitled “Wireless Headset,”, which is hereby incorporated by
`reference herein in its entirety.
`During use of device 10, earbud 16 is placed in a user’s ear.
`In this position, end 28 of device 10 extends downward,
`towards the user’ s mouth. Sound (e.g., from a telephone call)
`may be presented to the user through slots 18 of earbud 16. At
`end 28 of device 10, device 10 has a microphone that resides
`within housing 12. Opening 14 in housing 12 allows sound to
`be conveyed to the microphone.
`A button such as button 30 may be located at end 26 of
`device 10. Switch actuation member 20 reciprocates in direc-
`tions 22 along longitudinal axis 24 of device 10 (i.e., in and
`out of end 26 of device 10). Switch actuation member 20 and
`other suitable portions of device 10 in the vicinity of end 26
`may be formed ofplastic or other suitable dielectric materials.
`For example, button 30 may contain a structure that guides
`switch actuation member 20 along axis 24. This button guide
`structure may be formed ofplastic or other suitable dielectric.
`An antenna resonating element may be mounted to the
`button guide structure or other suitable dielectric portions of
`device 10 in the vicinity of button 30 and end 26. Because the
`materials used to form button 30 and device 10 at end 26 are
`
`dielectrics, radio-frequency signals may be readily received
`by the antenna and transmitted by the antenna without inter-
`ference button components.
`A cross-sectional side view ofdevice 10 is shown in FIG. 2.
`
`Microphone 54 may be mounted to a printed circuit board
`such as printed circuit board 52 or other suitable mounting
`structures. Circuit components for processing microphone
`signals may be mounted on board 52. A signal path such as
`flex circuit cable 48 may be used to convey signals between
`microphone board 52 and circuit board 42. Electrical compo-
`nents may be mounted to circuit board 42 (e. g., battery pro-
`tection circuits, control circuits, etc.).
`One or more light emitting diodes (LEDs) such as LED 44
`may be mounted in housing 12 for use as indicators. In the
`illustrative arrangement of FIG. 2, LED 44 has been mounted
`on printed circuit board 42 below hole 42 in housing 12. This
`allows light to escape from the housing 12 for viewing by a
`user.
`
`Housing 12 (FIG. 1) may be formed from first portion 12-1
`and second portion 12-2. First portion 12-1 may be formed of
`
`4
`
`aluminum, stainless steel, magnesium, titanium, other suit-
`able metals, alloys of these metals, and other suitable con-
`ductive materials. First housing portion 12-1 may also be
`formed partly or entirely from dielectric. Second portion 12-2
`may be formed from dielectric materials such as plastic. With
`one suitable arrangement, no significant amounts of conduc-
`tor are present at end 26 of device 10 to prevent interference
`with the antenna of device 10.
`
`A connector such as coaxial cable connector 40 may be
`mounted to printed circuit board 42. Coaxial cable 38 may be
`connected to printed circuit board 34 using miniature coaxial
`cable connector 36.
`
`Printed circuit board 34 may contain electronic compo-
`nents such as radio-frequency transceiver circuits. The radio-
`frequency transceiver circuitry of device 10 may support
`wireless communications over any suitable communications
`bands. Examples of communications bands that device 10
`may support include the Bluetooth band at 2.4 GHZ, the
`WiFi® communications bands, the wireless USB band, etc.
`With one suitable arrangement, which is described herein as
`an example, transceiver circuitry 34 supports Bluetooth com-
`munications between device 10 and an associated handheld
`
`electronic device (e.g., a cellular telephone handset or a
`hybrid cellular telephone and music player device).
`Speaker 32 may be used to generate sound for the user of
`device 10. For example, when the user is using device 10 to
`conduct a telephone call, speaker 32 may be used to present
`audio from the telephone call. When device 10 is used as a
`music player, speaker 32 may be used to play music for the
`user. A source of power such as battery 50 may be used to
`power device 10.
`A switch such as switch 56 may be mounted to circuit
`board 42. Switch actuation member 20 reciprocates in direc-
`tions 22 along axis 24. When a user desires to perform a
`function associated with button 30, the user may press button
`outer surface 62. Button outer surface 62 may be pressed to
`force end 58 of switch actuation member 20 against switch
`56. Depending on the type of switch being used (e.g., nor-
`mally open, normally closed, etc.) pressing against switch 56
`causes switch 56 to open or close. Electrical signals from
`switch 56 may be passed to circuitry on boards such as boards
`52, 42, and 34. The control circuitry on these boards may
`process the switch signals and take appropriate action.
`Examples of actions that may be taken in device 10 when
`switch 56 is operated include turning device 10 on or off,
`resetting device 10, changing the mode of operation of device
`10, etc. The control circuitry of device 10 may take actions
`based on single presses of button 30 or multiple presses of
`button 3 0. For example, a particular action may be taken when
`three rapid button presses are detected within a predetermined
`time interval.
`
`A guide structure is provided in housing portion 12-2. The
`guide structure helps to support and guide switch actuation
`member 20. Any suitable mechanical arrangement may be
`used to support and guide switch actuation member 20 in
`button 30. With one suitable arrangement, which is described
`herein as an example, the guide structure includes portions
`that define a guide channel. Switch actuation member 20 has
`a stem that reciprocates along the channel. The channel may
`have elevated ribs or other raised portions that help to reduce
`friction between the sidewalls of switch actuation member 20
`
`and the surfaces of the guide channel as the guide structure
`supports and guides switch actuation member 20.
`The antenna of device 10 has a ground (sometimes referred
`to as a ground plane). The ground may be formed from any
`suitable conductive structures in device 10. For example, the
`antenna ground may be formed from conductive housing
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`US 8,270,915 B2
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`5
`portion 12-1, layers of conductor on printed circuit boards
`such as board 42, combinations of such conductive structures,
`etc. The antenna of device 10 also has an antenna resonating
`element 60. Antenna resonating element 60, which is some-
`times referred to as the antenna of device 10, may be mounted
`to the guide structure or other suitable structure associated
`with button 30. Because the structures that make up button 30
`are primarily or entirely formed ofdielectric, the antenna may
`function properly without interference from metal compo-
`nents in device 10 (e. g., circuit components on board 42) and
`without interference from the metal or other conductors that
`
`may be used in forming housing portion 12-1.
`Antenna resonating element 60 is spaced away from hous-
`ing portion 12-1 and the electrical components of device 10
`such as the components on board 42 by distance D. Distance
`D can be selected to ensure that the spacing between the
`electrical components and housing materials of device 10 and
`antenna resonating element 60 are sufficient for satisfactory
`antenna performance. The distance D may be, for example,
`about 3-10 mm. Larger distances D offer greater clearance
`between the antenna resonating element and the electrical
`components of device 10, but require use of a housing portion
`such as portion 12-2 that is more elongated along axial dimen-
`sion 24.
`
`Because antenna resonating element 60 is mounted within
`the portion of device 10 that is being used by button 30, it is
`not necessary to increase the size of device 10 to accommo-
`date antenna spacing D. No space is wasted, because antenna
`resonating element 60 is mounted to dielectric structures that
`are already being provided to support the operation of button
`30. Button 30 therefore serves at least two functions. First,
`button 30 uses switch 56 to provide a control mechanism for
`device 10. Second, button 30, by serving as a support struc-
`ture for antenna resonating element 60, creates clearance
`between antenna resonating element 60 and conductive hous-
`ing portion 12-1 and/or other conductive structures in device
`10 such as electrical components on board 42. Because the
`structures of button 30 serve as both button structures and as
`
`antenna support structure, button 30 and antenna resonating
`element 60 are sometimes collectively referred to as a button
`and antenna assembly, as a button structure or assembly, as an
`antenna structure or assembly, as a button, as an antenna, etc.
`An exploded perspective view of an illustrative embodi-
`ment ofbutton 3 0 is shown in FIG. 3 . As shown in the example
`of FIG. 3, button 30 may have switch actuation member 20,
`button guide structure 64, switch 56 mounted on a printed
`circuit board such as board 42, and a button housing.
`The button housing for button 30 may be formed from
`device housing portion 12-1. This allows device 10 to retain
`an esthetically pleasing appearance. For example, the sur-
`faces of button housing 12-1 and housing portion 12-1 may
`have similar colors and textures, so that it is not apparent to a
`user of device 10 that two separate housing portions are in
`use. Rather, to the user, it can appear as if device 10 is formed
`of a single unitary housing.
`Circuit board 42 and button 30 may be attached to each
`other. With one suitable approach, housing portion 12-1 has
`guiding grooves 70. During assembly of button 30, edges 72
`of circuit board 42 may slide into grooves 70. Cyanoacrylate
`glue or other suitable adhesives may be used to secure circuit
`board edges 72 to grooves 70. Other adhesives (e. g., ultravio-
`let-light cured epoxy) may be placed on printed circuit board
`surfaces 84, to help secure board 42 in button 30.
`Button guide structure 64 has members 66 that receive
`surfaces 84 of board 42 and help to hold board 42 in place
`within button 30. Button guide structure 64 may be formed
`from a non-opaque material such as clear polycarbonate. This
`
`6
`ensures that ultraviolet light that is applied to button 3 0 during
`manufacturing can reach ultraviolet-curing adhesives that
`have been applied to surfaces such as surfaces 84.
`Button guide structure 64 may have a guide channel 68 that
`receives stem 86 of switch actuation member 20. During
`operation, switch actuation member 20 reciprocates back and
`forth along longitudinal axis 24 in directions 22. As switch
`actuation member 20 reciprocates, stem 86 reciprocates in
`channel 68. Gussets 76 on switch actuation member 20 pro-
`vide structural support for stem 86. Button guide structure 64
`may have recesses that accommodate gussets 76 when switch
`actuation member 20 is pressed fully inward in direction 88.
`Ribs may be formed along the inner surfaces of channel 68
`to help provide a low-friction guide path for stem 86. When
`pressed inward in direction 88, end 58 of switch actuation
`member 20 may press against surface 90 of switch 56 or other
`suitable switch actuation surface. This closes or opens a cir-
`cuit between a pair of contacts within switch 56 or otherwise
`operates the switch 56 so that suitable actions may be taken by
`the control circuitry of device 10.
`Switch 56 may be a side-actuated dome switch or any other
`suitable type of switch. In a side actuated dome switch, a
`rocker resides within the housing of the switch. As end 58 of
`switch actuation member 20 presses sideways in direction 88
`against the rocker, the rocker bears against the switch housing
`and translates this sideways motion into vertical motion
`towards the surface of board 42. A dome switch may be
`mounted directly beneath the rocker, so downward motion of
`the rocker presses against the dome switch and causes switch
`contacts that are associated with the dome switch to become
`
`shorted together (or opened). Control circuitry in device 10
`may sense the closing (or opening) of switch 56.
`In addition to guiding stem 86, button guide structure 64
`may serve as a support structure for antenna resonating ele-
`ment 60. Antenna resonating element 60 may be formed from
`a conductive strip or any other suitable antenna structure. A
`typical conductive strip may be about 0.6 mm in width and
`may have a length that is appropriate for handling the fre-
`quencies in the communications band of interest for device
`10. Conductive strips may be formed of metal or other suit-
`able conductors and may be straight, serpentine, curved, or
`any other suitable shape. Illustrative metals that may be used
`for resonating element 60 include copper, silver, gold, and
`brass. If desired, other metals or alloys ofthese metals may be
`used to form antenna resonating element 90. If the metal or
`other conductor that is used to form antenna resonating ele-
`ment 90 has a tendency to oxidize upon exposure to air,
`encap sulant may be used to ensure that the antenna resonating
`element 90 is hermetically sealed.
`Switch actuation member 20 may have a latch portion 74.
`During assembly, latch portion 74 is forced past a matching
`portion of button guide structure 64. Once past the matching
`portion ofbutton guide structure 64, switch actuation member
`20 and latch portion 74 snap into place. When switch actua-
`tion member 20 is withdrawn in direction 90, surface 92 of
`latch 74 catches on button guide structure 64, thereby pre-
`venting switch actuation member 20 from being removed
`from button 30.
`
`Switch actuation member 20 may have button head portion
`78. During operation, a user may use a finger to press against
`surface 62 of button portion 78. Portion 78 may be formed
`from a single material or multiple materials. The illustrative
`arrangement of FIG. 3 shows how button portion 78 may be
`formed from two different plastic portions 80 and 82 using a
`double shot process. Outer plastic portion 82 may be formed
`from clear polycarbonate to add gloss to the exposed button
`surface. Portion 80 may be formed from a plastic based on
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`65
`
`13
`
`13
`
`

`

`US 8,270,915 B2
`
`7
`(sometimes
`copolymers
`acrylonitrile-butadiene-styrene
`referred to as ABS plastic). ABS plastic flows well during
`molding operations and is suitable for forming small parts.
`Button guide structure 64 may be formed ofpolycarbonate
`(e.g., clear polycarbonate that permits ultraviolet light to
`reach ultraviolet-cured adhesive on surfaces 84). Stem 86,
`which reciprocates within channel 68 of guide structure 64,
`may be formed as a unitary part with portion 80. By forming
`stem 86 from ABS plastic, potentially squeaky polycarbon-
`ate-to-polycarbonate surface contact between stem 86 and
`channel 68 of guide structure 64 is avoided.
`Housing portion 12-1, which serves as the enclosure for
`button 30, may be formed from a blend of polycarbonate and
`ABS plastic. This type of blend provides device 10 with an
`attractive appearance. The ABS portion ofthe blend may help
`housing portion 12-1 from becoming too brittle.
`Although shown as being formed from three separate plas-
`tic structures in FIG. 3, button 30 may be formed from any
`suitable dielectrics. Some conductive materials (e.g., portions
`of switch 56) are associated with button 30, but these mate-
`rials are insignificant when compared to the overall size and
`shape of the dielectric portions of button 30. Moreover,
`switch 56 is located away from antenna resonating element 60
`to ensure sufficient clearance around antenna resonating ele-
`ment 60.
`
`Antenna resonating element 60 may be formed from a strip
`of metal that is aflixed to button guide structure 64 using
`adhesive or other suitable attachment mechanisms. With one
`
`particularly suitable arrangement, resonating element 60 may
`be formed from a strip of conductor that is part of a flex
`circuit. Flex circuits, which are sometimes referred to as
`flexible printed circuit boards, may be formed from polyim-
`ide and other flexible substrates. Copper strips or other suit-
`able conductive strips may be pattered on the flex circuit
`substrate to form antenna resonating element 60. During
`assembly, the flex circuit that contains antenna resonating
`element 60 may be mounted to button guide structure 64.
`If desired, the flex circuit or other suitable structure used
`for forming antenna resonating element 60 may be attached to
`an inner surface of button guide structure 64 (e.g., along the
`inner surface of channel 68). As shown in FIG. 4, another
`suitable technique involves attaching antenna resonating ele-
`ment 60 to outer surface 94 of button guide structure 64 by
`wrapping flex circuit 96 and embedded antenna resonating
`element 60 around button guide structure 64. Arrangements
`in which flex circuit 96 is attached to an exposed outer surface
`of button guide structure 64 are generally considered to be
`easier to manufacture than arrangements in which flex circuit
`96 or another antenna structure is mounted within button
`
`guide support 64. Configurations in which antenna resonating
`element 60 is mounted to the exterior of button guide struc-
`ture 64 are therefore described herein as an example.
`Flex circuit 96 may contain registration features such as
`hole 98 and other suitable registration structures. When flex
`circuit 96 is wrapped around button guide structure 64, the
`registration features may engage associated registration
`structures on button guide structure 64 such as boss 100. This
`helps to ensure proper alignment of flex circuit 96 and
`antenna resonating element 60 relative to button guide struc-
`ture 64. Bosses such as boss 100 may serve both as registra-
`tion structures and as heat stake structures that are used to
`
`attach flex circuit 96 to button guide structure. When the
`bosses are used as heat stake structures, heat is applied to the
`tips of the bosses. The heat deforms and enlarges the tips of
`the bosses so that the flex circuit 96 is retained. Flex circuit 96
`
`may also be aflixed to outer surface 94 using adhesive. With
`one suitable arrangement, flex circuit 96 is formed from adhe-
`
`8
`sive-backed flex circuit material having multiple registration
`holes that mate with corresponding registration bosses on
`button guide structure 64. At least one of the registration
`bosses may be heat treated to help secure flex circuit 96.
`A top view of a portion of circuit board 42 in the vicinity of
`connector 40 is shown in FIG. 5. As shown in FIG. 5, con-
`nector 40 may be connected to coaxial cable 38. Connector 40
`has positive terminals (sometimes called signal terminals)
`104, which may be connected to pad 106 via conductive path
`108. Ground terminals 102 may be connected to the ground
`plane of device 10 (e.g., via buried interconnects and ground
`plane structures in board 42).
`Pad 106 may be electrically connected to antenna resonat-
`ing element 60 by a spring or other suitable conductive path.
`A schematic cross-sectional view ofbutton guide structure 64
`that shows how spring 110 may be used to interconnect pad
`106 on circuit board 42 with contact pad 112 on flex circuit 96
`is shown in FIG. 6. Contact pad 112 may be electrically
`connected to antenna resonating element 60. With one suit-
`able arrangement, antenna resonating element 60 is formed of
`copper and is coatedwith a sealing cap formed of solder mask
`material. The sealing cap can help to protect the copper ofthe
`antenna resonating element 60 from oxidation. A hole may be
`formed in the sealing cap to allow a gold plating to be formed
`for pad 112. Clip 110 may press against pad 112, as shown
`schematically in FIG. 6. If desired, clip 110 can be wrapped
`tightly around the exterior ofbutton guide structure 64 to help
`hold flex circuit 96 in place against button guide structure 64.
`A heat stake boss may be used to help secure clip 110 to
`button guide structure 64.
`A side view of button 30 after circuit board 42 has been
`
`attached to button guide structure 64 is shown in FIG. 7. As
`shown in FIG. 7, even though button guide structure 64 has a
`slanted shape (in this example), antenna resonating element
`60 is able to conform to the shape ofbutton guide structure 64
`when flex circuit 96 is wrapped around button guide structure.
`FIG. 8 shows a suitable shape that may be used for flex circuit
`96 when it is desired to wrap flex circuit 96 around a slanted
`button guide structure of the type shown in FIG. 7. In the
`illustrative arrangement of FIG. 8, flex circuit 96 has regis-
`tration holes 98 that may mate with corresponding bosses on
`button guide structure 64. Notch 114 may be used to accom-
`modate spring 110 ofFIG. 6.
`An end view of button 30 is shown in FIG. 9. As shown in
`
`FIG. 9, flex circuit 96 may be wrapped around button support
`structure 64 so that there is an overlap region 118. If desired,
`the length of f