`
` PHISON 2002
`PNY Technologies, Inc. v. Phison Electronics Corp
` Case IPR2014-00150
`
`
`
`Patent Application Publication
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`Patent Application Publication Aug. 2, 2007 Sheet 2 of 9
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`US 2007/0178769 A1
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`FIG. 3(A)
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`Patent Application Publication Aug. 2, 2007 Sheet 3 of 9
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`US 2007/0178769 A1
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`Patent Application Publication Aug. 2, 2007 Sheet 4 of 9
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`US 2007/0178769 A1
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`1/410
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`FABRICATE 1 CASING
`WITH PERIPHERAL
`WALLS INCLUDING SLOTS
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`WITH TABS EXTENDING
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`SUCH THAT CONTACT PADS ARE EXPOSED THROUGH
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`Patent Application Publication Aug. 2, 2007 Sheet 5 of 9
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`US 2007/0178769 A1
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`Patent Application Publication Aug. 2, 2007 Sheet 6 of 9
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`US 2007/0178769 A1
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`Patent Application Publication Aug. 2, 2007 Sheet 7 of 9
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`US 2007/0178769 A1
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`PRKJR ART
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`PRIOR ART
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`8
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`Patent Application Publication Aug. 2, 2007 Sheet 8 of 9
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`US 2007/0178769 A1
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`PRIOR ART
`
`FIG. 13(A)
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`Patent Application Publication Aug. 2, 2007 Sheet 9 of 9
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`US 2007/0178769 A1
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`PRIOR AR?
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`PRiOR ART
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`PR¥0R ART
`
`FIG. 15(3)
`
`10
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`US 2007/0178769 A1
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`Aug. 2, 2007
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`REDUCED-LENGTI-I, LOW’-PROFILE USB DEVICE
`AND CARD-LIKE CARRIER
`
`RELATED APPLICATIONS
`
`[0001] This application is a divisional of U.S. patent
`application Scr. No. ll/257,575, entitled “Reduced-Length,
`Low—Profile USB Device Anc Card—Like Carrier” filed Oct.
`24. 2005.
`
`FIELD OF THE INVENTION
`
`to portable electronic
`invention relates
`[0002] This
`devices, and more particularly to portable electronic devices
`that utilize the Universal-Serial-Bus (USB) specification.
`
`BACKGROUND OF THE INVENTION
`
`[0003] Rapid advances in technology in several areas have
`converged to enable small, portable memory cards with vast
`capacities. Flash memory technologies such as those using
`electrically—erasable
`programmable
`read—only memory
`(EEPROM) l1ave produced chips storing 128 M-Bytes or
`more. Small flash—memory cards have been designed that
`have a connector that can plug into a specialized reader, such
`as for compact-flash, secure-digital, memory stick, or other
`standardized fon11ats.
`
`[0004] More recently, flash memory cards are being sold
`that contain a USB connector. Such USB—flash memory
`cards do not require a specialized reader but can be plugged
`into a USB connector on a host system, such as a personal
`computer (PC). These USB—flash memory cards can be used
`in place of floppy disks. A USB—flash card can have a
`capacity of more than ten floppy disks in an area not much
`larger than a large postage stamp.
`
`FIG. 12(A) shows a prior—art flash—memory card
`[0005]
`with a conventional male USB connector. Flash memory
`chip 12 may be a I28 Mega-byte non-volatile chip or may
`have some other capacity. Controller chip 14 contains a
`flash—memory controller that generates signals to access
`memory locations within flash memory chip 12. Controller
`chip 14 also contains a USB interface controller that serially
`transfers data to and from flash memory chip 12 over a USB
`connection.
`
`[0006] Male USB connector 20 may be mounted on board
`10, which is a small circuit board with chips 12, 14 mounted
`thereon. Multi-layer printed-circuit board (PCB) technology
`can be used for board 10. A plastic case (not shown) can
`surround board 10.
`
`[0007] Male USB connector 20 contains a small connector
`substrate 16, wl1icl1 is often white ceramic. black rigid
`plastic, or another sturdy substrate. Connector substrate 16
`has four or more metal contacts 18 formed thereon. Metal
`contacts 18 carry the USB signals generated or received by
`controller chip 14. USB signals include power, ground, and
`serial diifcrential data D+, D—.
`
`[0008] Male USB connector 20 contains a metal case that
`wraps around connector substrate 16. The metal case
`touches connector substrate 16 on three of the sides of
`connector substrate 16. The top side of connector substrate
`16. holding metal contacts 18, has a large gap to the top of
`the metal case. On the top and bottom of this metal wrap are
`formed holes 15. USB connector 20 is a type-A USB
`connector.
`
`FIG. 12(B) shows a female USB socket connector
`[0009]
`22. Female USB socket connector 22 can be an integral part
`
`of a PC or other host system, or can be connected by cable
`21 to such a host system. Another comiector substrate 26
`contains four metal contacts 28 that make electrical contact
`with the four metal contacts 18 of the male USB connector
`20 of FIG. 12(A). Comiector substrate 26 is wrapped by a
`metal case, but small gaps are between the metal case and
`connector substrate 26 or1 the lower three sides.
`
`[0010] Locking is provided by metal springs 24 in the top
`and bottom of the metal case. When male USB connector 20
`of FIG. l2(A) is flipped over and inserted into Female USB
`socket connector 22 of FIG. 12(B), metal springs 24 lock
`into holes 15 of male USB connector 20.
`
`[0011] FIGS. 13(A) and 13(B) are cross—sections high-
`ligl1tir1g connections between male and female USB con-
`nectors. Female USB socket connector 22 is on the left while
`male USB cormector 20 is being inserted from the right.
`Male USB connector 20 is flipped over relative to the view
`of FIG. 12(A). Metal contacts 18 are formed on the lower
`surface of connector substrate 16 on male USB connector
`20, while metal contacts 28 are formed on the upper surface
`of connector substrate 26 on female USB socket connector
`22. Thus the metal contacts face one another to allow for
`electrical contact when male USB connector 20 is inserted
`into female USB socket connector 22 as shown in FIG.
`13(3).
`
`[0012] Metal springs 24 formed on the metal case sur-
`rounding connector substrate 26 on female USB socket
`connector 22 fit into holes on the metal case of male USB
`connector 20. This helps to lock the connectors together.
`
`[0013] A problem associated with the production of con-
`ventional male USB devices that utilize standard male USB
`plug connectors typically require lead-based soldering meth-
`ods to attach the standard plug structure (e.g., substrate 16
`and plug shell 11) to circuit board 10. Lead (Pb) is recog-
`nized as a hazardous material, and may at some point in time
`be banned from use. Lead-free soldering requires higher
`peak temperatures (about 240° C.) that can shrink or warp
`plastic substrates, thereby making such conventional USB
`plug connector structures unsuitable for lead—free fabrication
`processes.
`
`FIG. 14 shows a prior—art USB flash memory card
`[0014]
`using a low-profile USB connector. Male USB connector 20
`of FIGS. 13 and 14 is relatively large. The metal case in
`particular is cumbersome and increases manufacturing cost.
`Costs may be reduced by integrating male USB connector
`30 with board 32. Board 32 is a PCB that l1as flash memory
`chip 12 and controller chip 14 mounted thereon. Board 32 is
`extended to include male USB connector 30, which has
`metal contacts 38 formed on end 36 of board 32.
`
`[0015] The width and thickness of board 32 at end 36
`containing male USB connector 30 is designed to approxi-
`mately match that of connector substrate 16 of FIG. 12(A).
`Plastic case 34 can enclose board 32 but have an opening for
`metal contacts 38. Plastic case 34 can cover the bottom and
`sides of male USB connector 30 up to end 36 to emulate
`portions of the metal case of the male USB connector of
`FIG. 12(A).
`
`[0016] FIGS. 15(A) and 15(B) show cross—sections of the
`prior—art low-profile USB connector being inserted into a
`standard female USB connector. Board 32 that has male
`USB cormector 30 formed on end 36 is flipped over from the
`view shown ir1 FIG. 14, and end 36 is inserted into fer11ale
`USB socket connector 22 from the right side.
`
`11
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`Aug. 2, 2007
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`[0017] Metal contacts 38 are located on the lower surface
`of male USB connector 30. Plastic case 34 has an opening
`on the lower surface of male USB connector 30 to expose
`the metal contacts so they can make electrical connection
`with metal contacts 28 on the upper surface of connector
`substrate 26 of female USB socket connector 22 when
`inserted as shown ir1 FIG. 15(B).
`
`Plastic case 34 helps to fill the gate between board
`[0018]
`32 and the top edge of the metal case of female USB socket
`connector 22. However, no holes are provided in plastic case
`34, so metal springs 24 are pushed up slightly when male
`USB connector 30 is inserted into female USB socket
`connector 22. Plastic case 34 is also formed along the thin
`edges of board 32 and helps to fill in the gaps between
`connector substrate 26 and the sides of the metal case of
`female USB socket connector 22 that are above and below
`the plane of FIG. 15(B).
`[0019] There is currently a demand for USB devices that
`include large capacity memory chips, but are very small in
`size for easy transportation. A problem with miniaturizing
`low-profile USB connector 30 shown in FIG. 14 is that,
`although the height of the plug section of male USB con-
`nector 30 is reduced, the thickness of the plastic case 34 is
`significantly thicker than the plug portion. Thus, reducing
`the profile (height) of male USB connector 30 is limited in
`part by the height of flash memory chip 12 and controller
`chip 14. Further, reducing the overall length of male USB
`connector 30 is limited by the length of board 32, wl1icl1 ir1
`turn is limited by the space needed for flash memory chip 12,
`controller chip 14 and metal contacts 38. Moreover, even if
`it were possible to reduce both the height and length of the
`male USB connector 30, the resulting smaller card structure
`would necessarily be easier to accidentally bend or other-
`wise damage when not in use (i.e., when being carried in a
`user’s pocket). Further, because the plug shell is omitted.
`contacts 38 are essentially unprotected when the prior-art
`USB flash memory card is not in use, thus exposing metal
`contacts 38 to damage.
`low-profile
`[0020] What is needed is a reduced—length,
`USB device that has minimal outer dimensions, thus mini-
`mizing manufacturing costs. Further, what is needed is a
`card-like carrier for protecting the reduced-ler1gtl1,
`low-
`profile USB device that both suaports the peripheral edges
`of the device housing and covers the metal contacts when the
`USB device is not in use.
`
`SUMMARY OF THE INVENTION
`
`[0021] The present invention is directed to a USB device
`in which all of the device’s ICs are located on a lower
`surface of the Printed Circuit Board (i.e., opposite to the
`metal contacts) to minimize the device’s thickness, where at
`least one of the ICs is positioned on a relatively narrow plug
`portion of the PCB to minimize the device’s length, thereby
`providing a reduced—length, low-profile USB device having
`smaller outer dimensions and lower manufacturing costs
`when compared to conventional USB devices.
`[0022]
`I11 accordance with an aspect of the present inven-
`tion, a thickness of the USB device’s handle structure is
`substantially equal
`to and coplanar with the low-profile
`thickness of the USB device’s plug structure. To minimize
`the overall height (thickness) of the USB device to the
`thickness of the plug structure, a PCB Assembly is provided
`that includes metal contacts formed on a first (e.g., upper)
`surface of a PCB, ar1d all IC components (e.g., USB con-
`troller chip, flash memory chip, etc.) mounted on the oppo-
`
`lower) surface of the PCB. A housing is then
`site (e.g.,
`mounted or otherwise formed over the IC components (i.e.,
`over the lower surface of the PCBA) that includes a plug
`section extending opposite to the metal contacts to provide
`the necessary plug structure thickness, and a handle section
`that covers the IC components. The housing has a planar
`cover plate that is parallel to the PCB ar1d extends along the
`entire length of the USB device (eg, from a front edge of
`the plug structure to a rear edge of the handle structure).
`Accordingly, the thickness of the handle structure is made
`substantially equal to the plug structure thickness, which is
`required for secure and reliable connection to a standard
`female USB socket connector, thus producing a flat, low-
`profile (thin) structure that car1 be easily carried ir1 a user’s
`poc <et, or incorporated into a utility tool.
`[0023]
`In accordance with another aspect of the present
`invention, a USB controller IC of the reduced—length, low-
`profile USB device is mounted at
`least partially on a
`rela ively narrow PCB plug section of the PCBA, and in one
`specific embodiment is located directly below the metal
`con acts to facilitate a reduced length of the USB device.
`The PCB has a relatively wide handle section and the
`rela ively narrow plug section that extends from a front edge
`of the handle section. Larger ICs (e.g., flash r11er11ory chips)
`are mounted on the relatively wide handle section. The metal
`con acts are disposed on the upper surface of the relatively
`narrow plug section, which has a width that is determined by
`standard USB female connectors. The USB controller IC,
`which is electrically connected to the metal contacts and
`con rols USB—defined communication operations between
`the USB device and a host,
`is mounted onto the lower
`surface of the PCB at least partially on the PCB plug section,
`and in one embodiment is located directly below the metal
`con acts. By positioning the USB controller IC on the lower
`surface of the PCB plug section, and in particular below the
`metal contacts, instead of on the PCB handle section as in
`conventional USB devices, the PCB body section can be
`mace smaller (i.e., because the handle space conventionally
`used for the IC controller is no longer needed), thereby
`allowing a reduction in the overall length of the PCB handle
`section. As such, this arrangement facilitates the production
`of s iorter, low profile USB devices that require less material
`and, hence, are less expensive to manufacture.
`[0024] The present invention is also directed to a card-like
`carrier for protecting low-profile USB devices when not in
`use. The card-like carrier includes a frame-like base portion
`having peripheral walls surrounding a relatively wide main
`chamber, and art end portion that is attached to the base
`portion and includes end walls that define a relatively
`narrow slot. A reduced—length, low-profile USB device is
`mounted onto the carrier by inserting the plug structure
`through the main chamber into the slot tmtil a front edge of
`the handle structure abuts the end walls, and then rotating
`the handle structure downward into the main chamber until
`a peripheral edge of the handle structure is parallel to the
`carrier base portion. Support structures are provided on
`lower edges of the body portion peripheral walls, and one or
`more locking structures disposed along upper edges of the
`peripheral walls. In one embodiment, the locking structures
`include short protrusions that allow snap-coupling of the
`handle structure into the main chamber, and the support
`structures include rails that support a lower surface of the
`handle structure. Therefore, when the USB device snap-
`coupled into the carrier, the peripheral edge of the handle
`structure is surrounded by the peripheral wall of the carrier,
`thereby protecting the USB device housing from damage
`when not in use. In addition, the end portion includes a
`
`12
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`US 2007/0178769 Al
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`Aug. 2, 2007
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`protective cover wall that covers the metal contacts of the
`USB device plug structure,
`thereby protecting the metal
`contacts of the USB device from contamination or damage
`when not in use.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`Z0025: These and other features, aspects and advantages of
`the present invention will become better Lmderstood with
`rcgard to thc following dcscription, appended claims, and
`accompanying drawings, where:
`Z0026:
`FIGS. 1(A) a11d 1(B) are perspective and cross
`sectional side views showing an exemplary USB device
`according to an embodiment of the present invention;
`Z0027:
`FIGS. 2(A) and 2(B) are cross—sectional end views
`showing a standard female USB socket connector and the
`plug s ructurc of thc USB device of FIG. 1(A) in scparatcd
`and assembled conditions, respectively;
`Z0028:
`FIGS. 3(A) and 3(B) are perspective and cross-
`sectional side views showing a printed circuit board assem-
`bly (PCBA) of the USB device shown in FIG. 1(A);
`Z0029:
`FIG. 4(A) and 4(B) are exploded perspective ar1d
`assem Jled perspective views showing an USB device
`according to another embodiment of the present invention;
`Z0030:
`FIG. 5 is a How diagram showing a method for
`assemjling the USB device of FIG. 4(B) according to
`another cmbodimcnt of thc prcscnt invcntion;
`
`FIGS. 6(A), 6(B) and 6(C) are cross—sectional end
`Z0031:
`views depicting tl1e USB device of FIG. 4(B) during suc-
`cessive assembly stages;
`Z0032:
`FIG. 7 is an exploded perspective view showing an
`USB device and card-like carrier according to another
`embociment of the present invention;
`
`FIGS. 8(A) and 8(B) are cross—sectional side views
`Z0033:
`showing the USB device mounted inside the carrier of FIG.
`7;
`
`FIG. 9 is a perspective view depicting an assembly
`Z0034:
`including the USB device and carrier shown in FIG. 7;
`Z0035:
`FIG. 10 is a perspective view showing tl1e carrier
`of FIG. 7 with a USB device that includes a keychain in
`accordance with another embodiment of the present inven-
`tion;
`
`FIG. 11 is a perspective view showing a wireless
`Z0036:
`communication-type USB device produced in accordance
`with another embodiment of the present invention;
`Z0037:
`FIG. 12(A) shows a prior—art flash-n1emory card
`with a USB connector;
`
`0038:
`FIG. 12(B) shows a female USB connector;
`Z0039:
`FIGS. 13(A) and 13(B) are cross-sections high-
`lighting connections between male and female USB con-
`nectors;
`
`FIG. 14 shows a prior—art USB flash memory card
`Z0040:
`using a low—profile USB connector; and
`
`FIGS. 15 A) and l5(B) show cross-sections of thc
`Z0041:
`prior—art low—profile USB connector being inserted into a
`standard female LSB connector.
`
`DETAILED DESCRIPTION OF THE DRAWINGS
`
`presented to enable one of ordinary skill in the art to make
`and use the invention as provided in the context of a
`particular application a11d its requirements. As used herein,
`the terms “upper”, "upwards”, “lower”, and “downward” are
`intcndcd to provide rclativc positions for purposes of
`description, and are not intended to designate an absolute
`frame of reference. Various modifications to the preferred
`embodiment will be apparent to those with skill in the art,
`and the general principles defined herein may be applied to
`other embodiments. Therefore, the present invention is not
`intended to be limited to the particular embodiments shown
`and dcscribcd, but
`is to bc accordcd thc widcst scopc
`consistent with the principles and novel features herein
`disclosed.
`
`[0043] FIGS. 1(A) and 1(B) are exploded and assembled
`perspective views showing a reduced length,
`low-prolile
`U11iversal-Serial-Bus (USB) device 100A according to a first
`cmbodimcnt of thc prcscnt invention. USB dcvicc l00A
`generally includes a printed circuit board assembly (PCBA)
`110 and a plastic housing 150 that is fixedly mounted onto
`PCBA 110.
`
`[0044] Referring to the upper portion of FIG. 1(A) and to
`FIG. 3(A), PCBA 110 includes a printed circuit board (PCB)
`111 including a relatively wide PCB handle section 112 and
`a relatively narrow PCB plug section 114 that extends from
`a front end of PCB handle section 112. PCB 111 is a
`substantially flat substrate, and has opposing sides that are
`rcfcrrcd to below as upper (first) surface 116 and lowcr
`(second) surface 118. Formed on upper surface 116 in plug
`section 114 are a plurality of metal contacts 120. Metal
`contacts 120 are shaped and arranged in a pattern established
`by the USB specification. According to an aspect of the
`invention, at least one control integrated circuit (IC) 130 and
`zero or more auxiliary ICs 135 (e.g., a flash memory device
`or an RF communication circuit) are mounted solely on
`lower surface 118 (i.e., on the side of PCB 111 opposite to
`metal contacts 120). ICs 130 and 135 are electrically con-
`nected to each other and to metal contacts 120 by way of
`mctal traccs 131 and 136, a fcw of which bcing dcpictcd in
`FIG. 1(A) in a simplified manner by dashed lines. PCB 111
`is formed in accordance witl1 known PCB manufacturing
`techniques such that metal contacts 120 and ICs 130 and 135
`(as well as zero or more other circuit components, which are
`omitted for brevity) are electrically interconnected by a
`predefined network including conductive traces 131 and 136
`and other conducting structures that are sandwichcd bctwccn
`multiple layers of an insulating material (e.g., FR4) and
`adhesive.
`
`[0045] Housing 150 is arranged such that substantially all
`of the plastic used to form housing 150 is located below
`upper surface 116 of PCB 111. Housing 150 includes a
`pcriphcral wall 15] extending downward, pcrpcndicular to
`PCB 111, and a lower cover plate 152 that extends parallel
`to PCB 111. For discussion purposes, the portion of periph-
`eral wall 151 surrounding handle section 112 of PCB 111 is
`referred to below as handle wall section 151-1, and the
`section of peripheral wall 151 surrounding plug section 114
`of PCB 111 is referred to below as plug wall section 151-2.
`Similarly, the portion of cover plate 152 covering handle
`section 112 of PCB 111 is referred to below as handle cover
`section 152-1, and the section of cover plate 152 covering
`plug section 114 of PCB 111 is referred to below as plug
`covcr scction I52-2.
`
`[0042] The present invention relates to an improvement in
`low—profile USB CODJICCIOFS. The following description is
`
`[0046] Referring again to FIG. 1(A), a handle structure
`102 of USB device 100A is formed by handle wall section
`
`13
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`151-], handle cover section 152-], and the exposed upper
`surface 116 of PCB handle section 112. Similarly, a plug
`structure 105 of USB device 100A is formed by plug wall
`section 151-2, plug cover section 152-2, and the exposed
`upper surface 116 of PCB plug section 114.
`
`[0047] Referring to FIGS. 2(A) and 2(B), a thickness T1
`and width W1 of plug structure 105 is selected to produce a
`secure (snug) fit inside standard female USB socket con-
`nector 22 (described above). Referring to FIG. 2(A), a height
`H between metal contacts 28 (i.e., a lower surface of
`connector substrate 26) and a lower wall 23A of the sur-
`rounding metal case is set by the USB standard at approxi-
`mately 2.5 mm. Thickness Tl is set, for example, at 2.4 mm
`to assure a snug fit of plug structure 105 inside lower region
`25A of female USB socket connector 22 (i.e., without
`significant vertical wobble) with metal contacts 120 in
`secure electrical contact with metal contacts 28 (as indicated
`in FIG. 2(B)). Similarly. a width W between side walls
`23B-1 and 2313-2 of the metal case is set by the USB
`standard at approximately 12.5 mm. Width W2 of plug
`structure 105 (i.e., between the outermost surfaces of side
`walls 151-2A and 151-2B) is set, for example, at 12 mm to
`further assure the snug fit of plug structure 105 inside lower
`region 25A of female USB socket connector 22. Note that
`plug structure 105 is referred to as “low—profile" and “half-
`height” herein in that plug structure 105 is only inserted ir1to
`lower region 25A of female USB socket connector 22 (i.e.,
`side regions 25B—1 and 25B—2 and upper region 25C, which
`are normally occupied by the metal case of a standard male
`USB plug connector, remain unoccupied by low-profile plug
`structure 105).
`
`[0048] According to an aspect of the present invention,
`lower cover plate 152 includes a planar surface 152—S that is
`parallel to the PCB, and defines a single plane such that a
`first
`thickness T1 of plug structure 105 (i.e., measured
`between upper PCB surface 116 and planar surface 152S
`adjacent to metal contacts 120) is substantially equal to a
`second tl1ickr1ess T2 of handle section 102 (i.e., measured
`between upper PCB surface 116 and planar surface 152
`adjacent to IC 135. That is, as indicated in FIG. 1(B), USB
`device 100A is substantially flat along its entire length (i.e.,
`fro111 rear edge 151-1A to front edge 151-1B). lhe term
`“substantially flat” is meant to indicate that planar surface
`152S is substantially parallel to an uppennost surface of
`USB device 100A along its entire ler1gtl1. In the embodiment
`shown in FIG. 1(A) and 1(B), the uppermost surface of USB
`device 100A is defined in part by upper surface 116 of PCB
`111, which is parallel to planar surface 152 along the entire
`length of USB device 100A. Similarly, the term “substan-
`tially flat” is also intended to cover embodiments described
`below in which the housing includes a thin wall structure
`that is formed o11 or otherwise contacts the upper surface of
`the PCB. In these embodiments, the thickness T2 of handle
`structure 102 may differ by a small amount (e.g., 5% from
`thickness T1 of plug structure 105.
`
`[0049] According to another aspect of the present inven-
`tion, the “fiatness" associated with USB device 100A is
`achieved by mounting all of the IC “chips” and other
`electronic components of USB device l00A on lower sur-
`face 118 of PCB 111 (i.e., on the side opposite to metal
`contacts 120). That is,
`the minimum overall thickness of
`USB device 100A is determined by the thickness T1, which
`is required to maintain a snug connection between plug
`structure 105 and female USB socket connector 22 (as
`indicated ir1 FIG. 2(B)). Because this arrangement requires
`that metal contacts 120 be located at the uppermost surface,
`
`and that plug wall section 151-2 plug and cover section
`152-2 extend a predetermined distance below PCB 111 to
`provide the required thickness T1. Thus, the overall thick-
`ness of USB device 100A can be minimized by mounting the
`ICs 130 and 135 only on lower surface 118 of PCB 111. That
`is, if the ICs are mounted on upper surface 116, then the
`overall thickness ofthe resulting USB structure would be the
`required thickness Tl plus the thickness that the ICs extend
`above PCB 111 (plus the thickness of a protective wall, if
`used).
`
`[0050] According to another aspect associated with the
`embodiment shown in FIG. 1(A) and 1(B), upper surface
`116 of PCB 111 is entirely exposed or1 the upper surface of
`USB device 100A, thus facilitating the production of USB
`device 100A with a maximum thickness equal to thickness
`T1 ofplug structure 105. That is, because metal contacts 120
`are formed on upper surface 116, and upper surface 116
`defines the higher end of required plug structure thickness
`T1, the overall height of USB device 100A can be 1nini—
`mized by exposing upper surface 116 (i.e., by making any
`point on upper PCB surface 116 the uppermost point ofUSB
`device 100A). As indicated in FIG. 1(A), in accordance with
`feature specifically associated with USB device 100, periph-
`eral wall 151 extends around a11d covers the peripheral side
`edges of PCB 111, and an upper edge ofperipheral wall 151
`is coplanar with upper surface 116 of PCB 111. By covering
`the peripheral side edge of PCB 111, peripheral wall 151
`prevents objects from wedging between PCB 111 and hous-
`ing 150, thereby preventing undesirable separation of PCBA
`110 from housing 150.
`
`[0051] Referring to FIGS. 3(A) and 3(B), according to
`another aspect of the present invention, controller IC 130 at
`least partially extends onto plug section 114 on lower
`surface 118, and one or more auxiliary lCs 135 (e.g., flash
`memory devices and/or a RF communication circuits) are
`respectively mounted on handle section 112 on lower sur-
`face 118. As indicated in FIG. 3(B), electrical contact
`between metal contacts 120 and controller IC 130 is facili-
`tated by metal via structures 132 that extend through PCB
`111 using known methods. The positioning of USB control-
`ler IC 130 on plug portion 114 is facilitated by the smaller
`footprint of USB controllers. In accordance with a further
`aspect, as indicated by the dashed vertical line “V” in FIG.
`3(B), at least a portion of USB controller IC 130 is located
`directly below contact pads 120. By positioning USB con-
`troller IC 130 on lower surface 118 of PCB plug section 114,
`and in particular below metal contacts 120, instead of on
`PCB handle section 112 as in conventional USB devices, the
`overall length L of PCB handle section 112 can be shortened,
`thereby facilitating the production of shorter USB devices
`that require less material and, hence, are less expensive to
`manufacture.
`
`[0052] As set forth in the previous paragraphs, reduced-
`ler1gtl1, low-profile USB device 100A is made thinner (low
`profile) by mounting controller IC and auxiliary IC(s) 135
`on lower surface 118 of PCB 111, and is made shorter
`(reduced length) by moving controller IC 130 forward (i.e.,
`onto plug section 114 and/or below metal contacts 120).
`Accordingly, the present invention provides USB devices
`having minimal size and manufacturing costs by combining
`these features.
`
`[0053] Referring again to FIGS. 3(A) and 3(B), in accor-
`dance with another aspect of the present invention, PCBA
`110 is fabricated using lead-free soldering materials and
`processes. Lead (Pb) is recognized as a hazardous material,
`
`14
`
`
`
`US 2007/0178769 Al
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`Aug. 2, 2007
`
`and may at some future point in time be banned from use.
`Conventional USB structures that utilize standard USB plug
`connectors typically require lead-based soldering methods
`to attach the standard plug structure to a plastic substrate.
`Lcad-frcc soldcring rcquircs highcr pcak tcmpcraturcs
`(about 240° C.) that can shrink or warp such plastic sub-
`strates, thereby making such conventional USB plug con-
`nector structures unsuitable for lead-free fabrication pro-
`cesses. In contrast, because metal contacts 120 are formed
`directly on PCB 111. which is formed, for example, using
`FR4. In addition, ICS 130 and 135 are provided as surface
`mount components that don’t contain lcad in their pins/balls,
`thereby further enabling lead-free fabrication. After the
`lead-free PCBA fabrication process is completed, plastic
`housing 150 is formed and/or assembled onto PCBA 110
`according to the various specific embodiments described
`below to complete the manufacture of low-profile USB
`device 100A.
`
`FIGS. 4(A) and 4(B) are exploded and assembled
`[0054]
`perspective views showing an USB device 100B according
`to another specific embodiment of the present invention.
`USB device 100B generally includes a lower (first) housing
`portion 350C-1, and upper (second) housing portion 350C-
`2, a11d PCBA 110.
`
`[0055] Lower housing portion 350C-1 generally includes
`a lower (first) cover plate 352C (including a handle cover
`section 352C-1 and a plug cover section 352C.-2) and an
`inner pcriphcral wall 351C-1 (including a handle wall sec-
`tion 351C—11, a plug wall section 351C—12, a rear wall
`section 351C-13, and a front wall section 351C-14) extend-
`ing upward from (perpendicular to) opposing edges of cover
`plate 352C. Several support ribs 357C extend upward from
`plug cover section 352B-2 that, when assembled, contact
`and help support plug section 114 of PCB 111.
`
`[0056] Upper housing portion 350C-2 generally includes
`an outer peripheral wall 351C-2 (including a handle wall
`section 351C-21 and a plug wall section 351C-22) that are
`sized to fit over inner peripheral wall 351C—1 in the manner
`described below, and a thin plastic top plate 358C that is
`integrally formed on upper edges of handle wall section
`351C-21. Note that plug wall section 351C-22 defines an
`opening 354C.
`
`In accordance with an aspect of the present
`[0057]
`cmbodimcnt invention, lowcr housing portion 350C-1 and
`upper housing portion 350C-2 are fabricated such that the
`housing portions can be snap-coupled over PCBA 110
`during the housing assembly process. In particular,
`the
`respective peripheral walls of housing portions 350C-1 and
`350C-2 are constructed such that
`inner peripheral wall
`351C-1 can be inserted inside peripheral wall 351C.-2,
`whereby the outside surfaces of peripheral wall 351 C-1 abut
`the inside surfaces of peripheral wall 351C-2. In addition,
`either a slot or a tab are provided on the outside surface of
`inner peripheral walls 351-C1, and a corresponding tab or
`slot arc provided on thc insidc surfaces of outer pcriphcral
`wal