US20070254503A1

US20070254503A1 - Single elastomeric connector system to support rf, digital, audio and dc signals

Info

Publication number: US20070254503A1
Application number: US11/775,373
Authority: US
Inventors: Shanquan Bao; Liming Gao; Taojin Le; Bin Luo; Hongqi Wu
Original assignee: UTStarcom Inc
Current assignee: UTStarcom Inc
Priority date: 2006-04-06
Filing date: 2007-07-10
Publication date: 2007-11-01
Also published as: US7416450B2; TW200814436A; WO2007113701A2; US20070238363A1; WO2007113701A3

Abstract

A connector system employs a first connector moiety on an insertable miniaturized form factor card. A mobile information device (MID) has a printed circuit board having a second connector moiety with a frame mounted on the MID PCB for receiving the card and having a slot for engagement of an elastomeric connector element in alignment with the second connector moiety. The card is positioned by the frame for alignment of the first connector moiety with the elastomeric connector element. The elastomeric connector element is a single integrated element. The first connector moiety incorporates a plurality of contact pads on the card and the second connector moiety incorporates a like plurality of contact pads on the MID PCB. The contact pads include at least a first set of RF pads and the signals on the first and second connector moieties are arranged for cross talk shielding in the elastomeric connector.

Description

RELATED APPLICATIONS

This application is a continuation-in-part of U.S. application Ser. No. 11/308,559 filed on Apr. 6, 2006 entitled CONNECTOR FOR A HIGHLY INTEGRATED, INSTALLABLE MINIATURIZED FORM FACTOR CARD FOR WIRELESS COMMUNICATIONS FUNCTIONS having a common assignee with the present invention the disclosure of which is incorporated herein as though fully set forth.

BACKGROUND OF THE INVENTION

Related Art

U.S. patent application Ser. No. 11/308,221 filed on Mar. 13, 2006 entitled MINIATURIZED FORM FACTOR WIRELESS COMMUNICATIONS CARD FOR GENERIC MOBILE INFORMATION DEVICES, having a common assignee with the present invention and which is incorporated herein by reference in its entirety as though fully set forth, provides a system that allows communications capability to be inserted into a mobile information device without the usual lead times for design of wireless communications directly into the device itself. This system using a miniaturized form factor card provides the ability to integrate hardware, software, utilities and drivers which will allow true plug and play functionality for end users or mobile information device design houses. The desired functional capability is provided through an insertable card to eliminate the requirement for a separate CPU or applications processor in the mobile information device and additionally, provides a complete modem solution that will support multi-mode and multi-band.
Many insertable cards for communications capability will include digital, Direct Current (DC), Radio Frequency (RF) and audio frequency signal connection requirements with the mobile information devices in which the cards are inserted. It is therefore desirable to provide a connector system which simplifies the arrangement of the connector elements to reduce complexity and increase reliability of the system.

SUMMARY OF THE INVENTION

The present invention provides a connector system having a first connector moiety on an insertable miniaturized form factor card. A mobile information device (MID) has a printed circuit board having a second connector moiety and a frame mounted on the MID PCB for receiving the card and having a slot for engagement of an elastomeric connector element in alignment with the second connector moiety, the card positioned by the frame for alignment of the first connector moiety with the elastomeric connector element. The elastomeric connector element is a single integrated element.
In an exemplary embodiment, the first connector moiety incorporates a plurality of contact pads on the card and the second connector moiety incorporates a like plurality of contact pads on the MID PCB. Further, the contact pads include at least a first set of RF pads and the signals on the first and second connector moieties are arranged for cross talk shielding in the elastomeric connector.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the present invention will be better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:
FIG. 1A is an isometric view of the elements of a connector system for an insertable miniaturized form factor card for employing the present invention;
FIG. 1B is an isometric view of the system of FIG. 1A showing the printed circuit board (PCB) for the card and dual elastomeric connector elements;
FIG. 2 is an isometric view of an exemplary embodiment of the present invention with a frame and single elastomeric connector element;
FIG. 3A is an exploded front section view of an embodiment for contact pads on the miniaturized form factor card, MID and associated elastomeric connector element; and
FIG. 3B is a bottom partial view of the contact pads on the miniaturized form factor card as shown in FIG. 3A.

DETAILED DESCRIPTION OF THE INVENTION

To enhance the space savings and weight reduction to permit more compact portable devices with flexible designs and integrate chipsets with passive components into a common module, the system provided in copending patent application Ser. No. 11/308,559 filed on Apr. 6, 2006 entitled CONNECTOR FOR A HIGHLY INTEGRATED, INSTALLABLE MINIATURIZED FORM FACTOR CARD FOR WIRELESS COMMUNICATIONS FUNCTIONS, having a common assignee with the present invention and which is incorporated herein by reference as though fully set forth, employs integral connector systems having standard interfaces and indexing for mating to PC boards within the mobile information device platforms and to properly index and mate the miniaturized form factor card. To further simplify the connector system a single Elastomeric connector element in combination with connection pad arrangement on the insertable miniaturized form factor card and host Mobile Information Device (MID) is employed.
FIGS. 1A and 1B show a connector system for employing embodiments of the present invention having miniaturized form factor card 10 received within a frame 12 mounted to PC board 14 in a MID handset. Circuit connection to the MID PCB is provided in the embodiment shown by two elastomeric connector elements 16 a and 16 b, contained within connector receiving slots 18 a and 18 b in the frame. The Elastomeric connector elements receive the mating elements of a first connector moiety on the card. An exemplary elastomeric connector is a STAX™ connector produced by Tyco Electronics. For the digital signals connector, a STAX™ model LD connector is employed in exemplary embodiments. The elastomeric connector element engages contact pads on the PCB in the MID for completing the circuit functionality.
The card is installed in the MID, for the embodiment of the connector system shown in FIGS. 1A and 1B, by insertion vertically within frame 12 which receives the external edges 20 of the card. A hinged cover 22 is provided on the frame to secure the entire card within the frame after insertion, urging the connector moieties into firm engagement. PCB 24 with the card covers removed is shown in FIG. 1A with the elasomteric connector is shown exploded from the slot in the frame for greater clarity.
As shown in FIG. 2, a single Elastomeric connector element 26 according to the present invention is received in a single slot 28 in the frame. To allow the miniaturized form factor card to use one Elastomeric Connector to support RF, Digital, Audio and power signals cross talk interference among these signals, particularly cross talk interference among noisy high speed digital signals, highly sensitive audio (speaker and microphone) and RF signals, must be minimized. To accomplish cross talk reduction, the signals are arranged in a unique principle or sequence. In an exemplary ordering, RF pins are placed on one end of the connector for lowest noise affect from other signals. High speed digital pins such as USB, LCD bus are placed far away from RF and audio pins and digital ground and DC power pins are used as shielding pads and inserted in between noisy signal pins such as LCD pins and USB pins. Digital ground or DC power pins can be combined into wider pins to achieve improved shielding performance. Finally, low speed Digital pins such as Keypad, SIM or GPIO are used as buffer pins in close proximity to noisy signal pins such as UART.
As shown in FIGS. 3A and 3B, pad placement and size are employed to achieve the desired shielding effects. For the exemplary embodiment two sets of RF pins are employed at opposite ends of the connector. Using the card connector moiety for description of the contact pad arrangement, a first RF ground pin 30 and a second RF ground pin 32 employ a larger foot print in one or both axes to provide shielding for RF pin 34. RF ground 32 is shown with a double width as exemplary. Conductive layers 36 in the elastomeric conductor element interconnect the contact pads on the miniaturized form factor card and the MID PCB. For larger transverse footprint pads such as the second RF ground pin 32, a larger number of conductive layers, 38 and 40 as examples in the drawing, are employed which based on the granular nature of the conducting material in the elastomeric connector element, typically layers of silver embedded in silicone rubber, further enhances the shielding capability. For actual Elastomeric connector elements employed in exemplary embodiments, pitch of the Conductive Layers as low as 0.13 mm (0.005″) is employed which provides three to four conductive layers typically in contact with 0.5 mm wide pads. Three to four non-conductive layers typically separate adjacent 0.5 mm wide pads on 1.0 mm centers. The wide foot print ground pins in the exemplary embodiment discussed above provide approximately 1.0 mm width thereby contacting double the number of conductive layers. For the example embodiment in FIGS. 3A and 3B, the second set of RF pins incorporate large footprint RF ground pads 42 and 44 surrounding a second RF pin 46. Placement of the second RF pin set on the opposite end of the connector allows maximum segregation of the two RF elements.
Continuing the pin description inboard from the first RF pin set, a digital ground pad 48 is provided with an adjacent DC power pad 50 followed by pads 52 for speaker and microphone signals. Low speed digital signal pads 54, as described above, separate the audio pins from the LCD bus 56. A digital ground pad 58 segregates the LCD bus on the other side from low speed digital signal pad 60 which in turn further shields pad 62 which may be employed for SIM, USB or UART connection. The second RF pin set is further shielded using a second digital ground pad 64 adjacent the inner RF ground pad.
An exemplary pin ordering for optimized shielding may include an arrangement of RF pin|RF and Digital Ground|DC Power|Audio Pins (Speaker&Mic)|Digital Ground|SIM Pin|UART|Digital Ground|USB|Keypad pins|Digital Ground|LCD/Camera Bus.
Having now described the invention in detail as required by the patent statutes, those skilled in the art will recognize modifications and substitutions to the specific embodiments disclosed herein. Such modifications are within the scope and intent of the present invention as defined in the following claims.

Claims

1. A connector system comprising:

a first connector moiety on an insertable miniaturized form factor card;

a mobile information device (MID) printed circuit board having a second connector moiety;

a frame mounted on the MID PCB for receiving the card and having a slot for engagement of an elastomeric connector element in alignment with the second connector moiety, the card positioned by the frame for alignment of the first connector moiety with the elastomeric connector element;

the first and second connector moieties having signal arrangement for cross talk shielding in the Elastomeric connector.

2. The connector system defined in claim 1 wherein the first connector moiety comprises a plurality of contact pads on the card and the second connector moiety comprises a like plurality of contact pads on the MID PCB.

3. The connector system defined in claim 2 wherein the contact pads incorporate a first set of RF pads.

4. The connector system defined in claim 3 wherein the contact pads incorporate a second set of RF pads.

5. The connector system defined in claim 4 wherein the first set of RF pads is located at a first end of the connector moiety and the second set of RF pads is located at a second end of the connector moiety.

6. The connector system defined in claim 3 wherein the first set of RF pads incorporates a first RF ground pad, a second RF ground pad and an RF signal pad intermediate the first and second ground pads.

7. The connector system defined in claim 6 wherein the first and second RF ground pads have a larger footprint than adjacent pads.

8. The connector system defined in claim 2 wherein noisy digital pads are shielded using adjacent ground pads.

9. The connector system defined in claim 8 wherein noisy digital pads are further shielded using low speed digital pads.

11. A method for connection of a miniaturized form factor card on a mobile information device printed circuit board comprising the steps of:

providing a frame on the MID PCB to receive the card;

providing a first connector moiety on the card;

providing an elastomeric connector constrained by the frame and contacting a second connector moiety on the MID PCB;

arranging signals on the first and second connector moieties for cross talk shielding in the elastomeric connector

12. The method of claim 11 in which providing the first connector moiety comprises the step of forming a plurality of contact pads on a PCB in the card and a like plurality of pads on the MID PCB.

13. The method of claim 12 in which the step of arranging signals includes the step of providing first set of RF pads.

14. The method of claim 14 wherein the step of providing a first set of RF pads includes providing a first RF ground pad, a second RF ground pad and an RF signal pad intermediate the first and second ground pads.

15. The method of claim 13 in which the step of arranging signals further includes the step of providing a second set of RF pads.

16. The method of claim 15 wherein the second set of RF pads is located on an opposite end of the connector moiety from the first set of RF pads.

17. The method of claim 12 in which the step of arranging the signals includes the steps of shielding noisy digital pads using adjacent ground pads.

18. The method of claim 17 wherein the step of arranging the signals further includes shielding using low speed digital pads.

19. The method of claim 18 wherein the step of arranging the signals includes arranging the pads in the order of RF pin, RF and Digital Ground, DC Power, Audio Pins (Speaker&Mic), Digital Ground, SIM Pin, UART, Digital Ground, USB, Keypad pins, Digital Ground, LCD/Camera Bus.