WO2008083166A2

WO2008083166A2 - Electrical connector with grounding pin

Info

Publication number: WO2008083166A2
Application number: PCT/US2007/088836
Authority: WO
Inventors: Steven Sprouse; Ka Ian Yung; Suresh Upadhyayula; Patricio Collantes
Original assignee: SanDisk Corp
Current assignee: SanDisk Corp
Priority date: 2006-12-29
Filing date: 2007-12-26
Publication date: 2008-07-10
Anticipated expiration: 2009-06-29
Also published as: CN101627510A; US7354314B1; TWI350034B; TW200841532A; WO2008083166A3; KR101036327B1; KR20090116727A; CN101627510B

Abstract

A semiconductor device (100) is disclosed including a sheathless connector (102) having a grounding pin (120) which protects against electrical shorts, and damage upon a backwards insertion of the connector to a host device. If the electrical connector is inserted backwards, the grounding pin mates, with the signal ground terminal (46) of the socket (36), and avoids contact with the remaining terminals. As a result, the damage otherwise occurring upon a backwards insertion of prior art devices is avoided.

Description

ELECTRICAL CONNECTOR WITH GROUNDING PIN

BACKGROUND OF THE INVENTION

Field of the Invention

[0001] Embodiments of the present invention relate to a sheathless connector having a grounding pin which protects against a short circuit and damage upon a backwards insertion of the connector to a host device.

Description of the Related Art

[0002] The strong growth in demand for portable consumer electronics is driving the need for high-capacity storage devices. Non-volatile semiconductor memory devices, such as flash memory storage cards, are becoming widely used to meet the ever-growing demands on digital information storage and exchange. Their portability, versatility and rugged design, along with their high reliability and large storage capacity, have made such memory devices ideal for use in a wide variety of electronic devices, including for example digital cameras, digital music players, video game consoles, PDAs and cellular telephones.

[0003] Equally ubiquitous is the universal serial bus (USB) interface for transferring signals between devices such as those named above and other components such as for example desktop computers and the like. The USB interface is comprised of a male plug and female socket connectors. Plugs generally have one or more pins that are inserted into openings in the mating socket. While there are several types of USB connectors, the most commonly used is the type-A plug on which is a 4-pin connector, surrounded by a shield. A conventional type-A USB plug and socket are shown in cross-section in prior art Figs. 1 through 3. The conventional USB plug 20 shown in Fig. 1 may for example be attached to an electronic device and includes a base 22 on which is formed a signal power pin 24, a pair of signal pins 26, 28 and a signal ground pin 30. The base and pins are covered by a shroud 32. As seen in Fig. 2, the conventional USB socket 36 may be incorporated in a host device and includes a base 38 and four terminals 40 through 46 formed thereon (shown in phantom lines for clarity). As seen in Fig. 3, the plug may be received within the socket with pins 24 through 30 mating with pins 40 through 46 to allow transfer of signals between the electronic and host devices.

[0004] In conventional USB connections, the shroud provides a grounding path for electrostatic charges in the electronic device to be dissipated. However, some low profile USB connective devices are currently being made without the shroud, such as plug 50 shown for example in prior art Figs. 4 and 5. In order to provide a path to ground in the absence of a sheath, it is known to include a grounding plate 52 on a side of the base opposite the signal pins for contacting the conductive sides of the socket 36. For example, U.S. Patent No. 6,896,527, entitled, "Slim USB Male Connector with System Grounding," discloses a USB connective device including signal pins on a first side of the base and a ground plate on the opposite side of the base for providing a path to ground.

[0005] However, a drawback to known connectors is that, without a shroud, it is often possible to insert a USB plug into a socket in the wrong orientation, i.e., backwards. That is, as shown in prior art Fig. 6, the plug is inserted so that the pins 24 through 30 face the wrong way. In prior art connectors, such as that disclosed in the '527 Patent, a backwards insertion of the plug will result in the plate 52 engaging the power and ground terminals of the host device socket. Connecting the host device grounding terminal with the power terminal via the plate 52 can result in a short circuit and damage to the host device. There is therefore a need of an electrical connector having a grounding path but which does not run the risk of electrical short or damage upon a backward insertion of the connector to a host device.

SUMMARY OF THE INVENTION

[0006] One embodiment relates to a semiconductor device including a sheathless connector having a grounding pin which protects against electrical shorts and damage upon a backwards insertion of the connector to a host device. The semiconductor device includes an integrated circuit coupled to the electrical connector. A top portion of the connector may include a plurality of signal pins, including a signal ground pin adjacent a first edge of the connector and connected to a ground plane or circuit of the integrated circuit. A bottom portion of the connector may include a grounding pin adjacent a second edge of the connector and similarly connected to the ground plane or circuit of the integrated circuit.

[0007] The semiconductor device may further include a printed circuit board. In embodiments, the signal pins and grounding pin may be formed on the printed circuit board so that the electrical connector is integrally formed with the integrated circuit. In an alternative embodiment, the electrical connector may be formed separately from the printed circuit board and affixed thereto after the connector and printed circuit board are formed.

[0008] The electrical connector may be inserted into a socket of a host device having signal terminals including a signal ground terminal as explained in the Background section. When the connector is properly inserted into the socket, the signal pins engage their respective terminals in the socket. Upon proper insertion, the grounding pin in turn engages an electrically conductive surface of the socket, thereby providing a ground path for the semiconductor device. However, if the electrical connector is inserted backwards, the grounding pin mates with the signal ground terminal of the socket, and avoids contact with the remaining terminals. As a result, the damage otherwise occurring upon a backwards insertion of prior art devices is avoided.

DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 is a cross-sectional view of a conventional USB plug including a shroud.

[0010] Figure 2 is a cross-sectional view of a conventional USB socket of a host device.

[0011] Figure 3 is a cross-sectional view of a conventional USB plug with shroud mated within a USB socket.

[0012] Figure 4 is a cross-sectional view of a conventional shroudless USB plug.

[0013] Figure 5 is a cross-sectional view of a conventional shroudless USB plug within a socket of a host device.

[0014] Figure 6 is a cross-sectional view of a conventional shroudless USB plug inserted backwards into a USB socket of a host device.

[0015] Figure 7 is a top view of a semiconductor device in accordance with an embodiment of the present invention.

[0016] Figure 8 is a bottom view of a semiconductor device in accordance with an embodiment of the present invention. [0017] Figure 9 is a cross-sectional side view of a semiconductor device in accordance with an embodiment of the present invention.

[0018] Figure 10 is a cross-sectional end view of an electrical connector in accordance with an embodiment of the present invention.

[0019] Figure 11 is a cross-sectional end view of an electrical connector in accordance with an embodiment of the present invention properly inserted within a host device socket.

[0020] Figure 12 is a cross-sectional end view of an electrical connector in accordance with an embodiment of the present invention improperly inserted within a host device socket.

[0021] Figure 13 is a cross-sectional end view of an electrical connector in accordance with an alternative embodiment of the present invention improperly inserted within a host device socket.

DETAILED DESCRIPTION

[0022] Embodiments will now be described with reference to Figs. 7 through 13, which relate to a sheathless connector having a grounding pin which protects against electrical shorts and damage upon a backwards insertion of the connector to a host device. It is understood that the present invention may be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the invention to those skilled in the art. Indeed, the invention is intended to cover alternatives, modifications and equivalents of these embodiments, which are included within the scope and spirit of the invention as defined by the appended claims. Furthermore, in the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be clear to those of ordinary skill in the art that the present invention may be practiced without such specific details.

[0023] Referring now to the top, bottom and cross-sectional views of Figs. 7-9, respectively, there is shown a semiconductor device 100 including a USB connector 102 at a first end and an integrated circuit 104 at its second end. Though not critical to the present invention, integrated circuit 104 may include at least semiconductor die 104a and 104b and passive components 104c. The type and function of integrated circuit 104 is again not critical to the present invention, but in embodiments may be a flash memory device including one or more flash memory die and one or more controller die such as an ASIC.

[0024] The connector 102 shown is for a type-A USB connection to a host device, but it is contemplated that other types of USB connectors may include the present invention as described hereinafter. The electrical connector 102 includes a first edge 102a and a second edge 102b opposed to the first edge 102a.

[0025] As seen in the top view of Fig. 7 and the cross-sectional view of Fig. 9, a top surface of connector 102 includes a plurality of signal pins 106-112. Signal pins 106-112 may be conventional signal pins within a type-A USB connector. Pin 106 may be adjacent to edge 102a of the connector and may be a signal power pin for supplying a voltage to a semiconductor device to which USB connector 100 is attached as explained hereinafter. Signal pins 108 and 110 may transmit signals between the semiconductor device and a host device to which USB connector 100 is connected. Pin 112 may be adjacent to edge 102b and may be a signal ground pin connected to a ground plane or circuit within integrated circuit 104. The ground plane or circuit provides the semiconductor device 104 with a path to ground. Each of pins 106-112 may be exposed on an upper surface of the semiconductor device 100. [0026] Signal pins 106-112 and integrated circuit 104 may be formed on a printed circuit board ("PCB") 118. As is known in the art, PCB 118 may be formed of a core, having a top conductive layer formed on a top surface of the core, and a bottom conductive layer formed on the bottom surface of the core. During fabrication of the integrated circuit 104 on PCB 118, the conductive layers of the PCB 118 may be etched to define the pins 106-112 on the first surface, and grounding pin 120 (explained below) on the opposite surface. The conductance pattern may further include electrical traces 122 for electrically coupling pins 106-112 to the integrated circuit 104. Once patterned, the PCB 118 may be laminated with a solder mask as is known in the art.

[0027] Referring now to the bottom view of Fig. 8 and the cross-sectional view of Fig. 9, in accordance with the present invention, a grounding pin 120 may be formed on PCB 118 adjacent to edge 102b, on a side opposite to pins 106-112 and. The grounding pin 120 may be connected to the ground plane or circuit of integrated circuit 104 in any of various ways, including by a trace 124 and a via 126 formed on PCB 118. Grounding pin 120 may be plated with gold, a nickel/gold alloy or other plating material in a known plating process.

[0028] As seen in Fig. 9 but omitted from Figs. 7 and 8, the PCB 118 may be encapsulated within molding compound 128 in a known encapsulation process. The pins 106-112 on the top surface and the grounding pin 120 on the bottom surface are exposed through the surface of molding compound 128. In alternative embodiments, the integrated circuit 104 and connector 102 may be enclosed within lids or a frame instead of, or in addition to, molding compound 128

[0029] In the above-described embodiments, electrical connector 102 is integrally formed as part of printed circuit board 118. In an alternative embodiment to the present invention, electrical connector 102 including signal pins 106-112 and grounding pin 120 may be formed separate from PCB 118. In such an embodiment, after the PCB 118 is formed with integrated circuit 104, the electrical connector may be affixed to the PCB 118. Once affixed, signal pins 106-112 may be soldered to contact pads on PCB 118 to electrically couple pins 106-112 to the integrated circuit. Similarly, grounding pin 120 may be soldered to a contact pad on PCB 118 to electrically couple grounding pin 120 to the ground plane or circuit.

[0030] Fig. 10 is a cross-sectional view of electrical connector 102 showing signal pins 106-112 and grounding pin 120 on printed circuit board 118 within molding compound 122. Fig. 11 is a cross-sectional view of the electrical connector 102 mounted within a conventional socket 36 (as described in the Background section) of a host device. The socket 36 may include signal power terminal 40, signal terminals 42 and 44 and signal ground terminal 46 (socket 36 is shown in phantom lines for clarity).

[0031] When properly inserted, pins 106-112 engage terminals 40-46, respectively, as is known in the art to allow the exchange of signals between the semiconductor device 100 and the host device. Similarly, grounding pin 120 engages an electrically conductive surface of socket 36, thereby providing a ground path through the host device for the semiconductor device 100.

[0032] However, as explained in the Background section, it may be possible that a low profile USB connector is improperly inserted backwards. Such a situation is illustrated in Fig. 12. As shown, when inserted backwards, the grounding pin 120 mates with signal ground terminal 46, and avoids contact with terminals 40-44. As a result, the damage otherwise occurring upon a backwards insertion of prior art devices is avoided. It is understood that the width of pin 120 (i.e., the dimension extending in between edges 102a and 102b) may vary in alternative embodiments. For example, as shown in Fig. 13, the width of pin 120 may be greater than the corresponding width of terminal 46. In embodiments, the width may be increased to a point where the grounding pin 120 comes near to, but does not contact, terminal 44.

[0033] The foregoing detailed description of the invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the invention and its practical application to thereby enable others skilled in the art to best utilize the invention in various embodiments and with various modifications as are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the claims appended hereto.

Claims

CLAIMSWe claim:

1. An electrical connector for affixing an electronic device to a host device, the electrical connector comprising: a base including a first and second opposed surfaces, and first and second opposed edges extending between the first and second surfaces; a signal ground pin on the first surface for connecting the electronic device to ground potential, the signal ground pin positioned adjacent the first edge; a signal pin on the first surface for transferring signals between the electronic device and the host device, the signal pin positioned adjacent the signal ground pin and spaced a distance from the first edge; and a grounding pin on the second surface for grounding the electronic device, the grounding pin positioned adjacent the second edge and having a width in a direction between the first and second edges, the width being less than the distance the signal pin is spaced from the first edge.

2. An electrical connector as recited in claim 1, wherein the grounding pin is substantially the same size as the signal ground pin.

3. An electrical connector as recited in claim 1, wherein the width of the grounding pin is greater than a width of the signal ground pin.

4. An electrical connector as recited in claim 1, wherein the width of the grounding pin is less than a width of the signal ground pin.

5. An electrical connector as recited in claim 1, the first surface further comprising a second signal pin and signal power pin adjacent the signal pin.

6. An electrical connector as recited in claim 1, wherein the electrical connector is capable of fitting within a USB receptacle of the host device.

7. A flash memory device capable of operating with a host device via a USB receptacle of the host device, the flash memory device comprising: an electronic device; and an electrical connector capable of fitting within the USB receptacle of the host, the electrical connector including: a base including a first and second opposed surfaces, and first and second opposed edges extending between the first and second surfaces, a signal ground pin on the first surface for connecting the electronic device to ground potential, the signal ground pin positioned adjacent the first edge, a signal pin on the first surface for transferring signals between the electronic device and host device, the signal pin positioned adjacent the signal ground pin and spaced a distance from the first edge, and a grounding pin on the second surface for grounding the electronic device, the grounding pin positioned adjacent the second edge and having a width less than the distance the signal pin is spaced from the first edge.

8. A flash memory device as recited in claim 7, wherein the grounding pin is substantially the same size as the signal ground pin.

9. A flash memory device as recited in claim 7, wherein the width of the grounding pin is greater than a width of the signal ground pin.

10. A flash memory device as recited in claim 7, wherein the width of the grounding pin is less than a width of the signal ground pin.