WO2002029934A1

WO2002029934A1 - Connector device

Info

Publication number: WO2002029934A1
Application number: PCT/SE2001/002119
Authority: WO
Inventors: Ulf Palin
Original assignee: Allgon Mobile Communications Ab
Priority date: 2000-10-02
Filing date: 2001-10-01
Publication date: 2002-04-11
Also published as: SE0003533D0; SE519385C2; AU2001292495A1; SE0003533L

Abstract

A connector device for use in a portable radio communication device, such as a mobile phone, comprises an conductive elongated element with a longitudinal axis and having a first and a second end portion, wherein the elongated element is arranged to be attached at the first end portion to e.g. an antenna element. A separate spring element adapted to exert a spring force essentially in the direction of said longitudinal axis is attached to the second end. The spring element provides a well-defined electrical connection between the body and a substrate, such as a PCB of the mobile phone. This solution provides for a compact, inexpensive connector device with is well suited for RF applications.

Description

CONNECTOR DEVICE

FIELD OF INVENTION

The present invention relates generally to electrical connectors and more particularly to a connector device adapted for use in a portable radio communication device, such as a mobile phone. It also relates to an antenna device and a portable radio communication device, such as a mobile phone, comprising such a connector or antenna device.

BACKGROUND

It is previously known so-called contact pins in the technical field of mobile phones. Such contact pins are used as radio frequency contact means between for example a built in or internal radiating element and a printed circuit board (PCB). An example of such pins is sold under the trademark PoGo, so-called PoGo-pins. Because there are radio frequency applications involved, it is of vital importance that the contact point is well defined, as otherwise the RF characteristics will vary for the radiating element in an unwanted way.

Mobile phones are also subject to cost reduction demands as well as increasing adaptation for large scale manufacturing. For that reason parts included in a mobile phone are preferably designed to ensure low manufacturing and assembling costs. The above mentioned PoGo-pins are rather complicated, comprising a sleeve with a spring therein exerting a spring force on a contact element. The complicated nature of that design makes it worthwhile to look for more inexpensive solutions .

Another problem with prior art connectors using a helical spring or the like is that the electrical parameters, notably inductance and capacitance, vary with the length of the spring. Thus, in some applications in which the spring is compressed, this compression creates unwanted variations in the RF characteristics. Furthermore, the use of a helical spring sets a lower limit on the length of the connector device.

Another drawback with some prior art solutions is that the connector device occupies space that otherwise could be used as an effective radiating area of a radiating element.

The German utility patent document DE 198 52 636 Al discloses a connector element with an holding portion and a contact end interconnected by a spring portion. The contact end is adapted for soldering to an object and the entire connector element is unitary. This makes the described connector element unsuited for RF applications. It is also difficult to adapt the described connector to different lengths, making assembly difficult.

SUMMARY OF THE INVENTION

An object of the present invention is to provide a connector device for use in a portable radio communication device wherein the contact point between the connector and a contacted object is well defined and the connector is adapted for good RF signal transfer.

Another object of the present invention is to provide a connector device, which is easy and inexpensive to manufacture and assemble.

The invention is based on the realization that the above mentioned objects can be achieved by providing a contact pin with a separate spring element provided at one end portion thereof .

According to the present invention there is provided a connector device as defined in appended claim 1.

In another aspect of the present invention there is provided an antenna device as defined in appended claim 18.

In yet another aspect of the present invention there is provided a portable radio communication device as defined in appended claim 20.

With the inventive connector device the above mentioned drawbacks of prior art are eliminated or at least mitigated. The connector device according to the present invention as defined by the appended claims provides a connector device that is easy to manufacture and assemble and that provides a well defined path for RF signals passing between two objects, such as a radiating element and a printed circuit board of a mobile phone.

The dependent claims define further preferred embodiments of the inventive RF connector. BRIEF DESCRIPTION OF DRAWINGS

The invention is now described, by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a first embodiment of a connector device according to the invention;

FIG. 2 is an enlarged view of the lower end portion of the connector device shown in FIG. 1;

FIGS 3 and 4 are side and front views respectively, of the connector device shown in FIG. 1;

FIG. 5 is an exploded view of the connector shown in FIG. 1;

FIG. 6 is a perspective view of a second embodiment of a connector device according to the invention;

Fig. 7 is an enlarged view of the lower end portion of the connector device shown in FIG. 6;

FIGS 8 and 9 are side and front views respectively, of the connector shown in FIG. 6;

FIG. 10 is a detailed view of a spring element used with the connector shown in FIG. 6;

FIG. 11 is a perspective view of the connector shown in FIG. 1 used with a first embodiment of a connector support;

FIG. 12 is detailed view of the support shown in FIG. 11;

FIG. 13 is a view of a second embodiment of a connector support before mounting; and FIG. 14 is a detailed view of the support shown in FIG. 13.

DETAILED DESCRIPTION OF THE INVENTION

In the following, a detailed description of two embodiments of a connector device according to the invention will be given. In the description, for purposes of explanation and not limitation, specific details are set forth, such as particular hardware, applications, techniques etc. in order to provide a thorough understanding of the present invention.

However, it will be apparent to one skilled in the art that the present invention may be utilized in other embodiments that depart from these specific details. In other instances , detailed descriptions of well-known methods, apparatuses, and circuits are omitted so as not to obscure the description of the present invention with unnecessary details.

A first embodiment of a connector device according to the invention will now be described with reference to FIGS. 1-5. A connector, generally designated 1, comprises an elongated pin element 10 having a circular cross-section with a diameter of e.g. 1 millimeter. The pin element is made of an electrically conductive material, such as copper, a copper alloy, or stainless steel, or it can be provided with a plating of a suitable material, such as gold or a suitable corrosion resistant alloy. As the pin element 10 functions as a guide for RF signals, high conductivity is of importance. Thus, the pin element comprises an elongated body 12, the upper end portion 16 of which is adapted to be attached to a radiating antenna element 20 in some suitable way, such as by soldering, riveting or welding or by means of a so-called star-lock arrangement. In this embodiment and the embodiment described below, the radiating element is described as a planar conductive element made of for example sheet metal and having an essentially square or rectangular shape. However, it is to be realized that in practice the radiating element can take many different shapes and the rectangular shape shown in the figures is just a general outline of the shape of the radiating element. Also, although the radiating element preferably is made of a sheet metal, also other solutions are viable, such as a plastic support having a conductive flex film attached thereto and functioning as an antenna pattern.

The configuration of the pin element 10 enables a mounting to the radiating element which provides for an efficient utilization of the radiating element area, i.e., the attachment area comprising e.g. a rivet does not occupy a large area that could have been used for the radiating element itself as is the case in some prior art solutions.

The pin element 10 is provided with a circumferential groove, creating a waist portion 14 close to the lower end portion 18 of the pin element 10, see FIG. 5. The function of this waist portion 14 will be described below. The connector device 1 also comprises a spring clip 30 with a shape generally resembling an "U" turned over 90°. The spring clip thus has an upper leg portion 32 and a lower leg portion 34 with a typical mutual dis- tance "d" of about 1 millimeter, see FIG. 3. The upper leg portion 32 is provided with a cut-out portion 36, see FIG. 5, having a width essentially corresponding to the diameter of the waist portion 14. During assembly the waist portion 14 is fully inserted into the cut out portion 36 of the upper leg portion 32, thereby attaching the spring clip 30 to the pin element 10. The cut-out portion 36 is preferably narrower at the outer end thereof, having a width slightly less than the diameter of the waist portion of the pin element, thereby retaining the waist portion in a fixed position.

The lower leg portion 34 is provided with a generally circular protrusion 38 at the underside thereof. The protrusion 38 functions as a contact point to an underlying substrate, such as a printed circuit board (PCB) 40 of a mobile phone 50, the general outlines of which are denoted by dashed lines, see FIGS. 3 and 4. On the PCB 40 there is provided a contact pad of some conductive material (not shown), thus establishing a path to RF electronics on the PCB. The pad typically has an area of 2x2 millimeters, although the size can vary.

As is clearly apparent from FIGS. 3 and 4, the protrusion 38 is positioned on the center axis of the pin element 10. This is particularly advantageous as the forces exerted by the connector device are directed in a direction perpendicular to the planes of the antenna element 20 and the PCB 40. This eliminates any radial forces that possibly can change the position of the protrusion on the PCB, thereby altering the RF charac- teristics of the signal path.

The protrusion is created e.g. by means of a stamp process, etching, or milling. Alternatively, the protrusion 38 can be provided as part of a gold-plated wire or the like that is welded onto the underside of the lower leg portion 34. Thus, the provision of the protrusion 38 ensures a well-defined connection between the connector device 1 and the PCB 40, an important aspect in RF applications .

Also, the signal path through the spring clip is rela- tively short, which ensures good RF characteristics for the connector device.

The provision of a separate spring clip is advantageous when considering manufacturing and storage aspects, as only one type of spring clip has to be manufactured and stored. The pin element 10 is then manufactured in different lengths typically ranging from 4 to 12 millimeters but shorter or longer pin elements are also possible. This modular concept reduces manufacturing costs and also provides a solution wherein less storage space is required.

The described connector device can be made very short; to the length of the pin body 12 is only added the distance between the lower end portion 18 of the pin element and the lower leg portion 34 of the spring clip 30, which typically is less than 1 millimeter. This distance varies in a very small degree, ensuring well-defined electrical characteristics of the connector device.

A second embodiment of a connector device according to the invention will now be described with reference to FIGS. 6-10, which essentially correspond to FIGS. 1-5 of the first embodiment. Like parts in the two embodiments are given the same reference numeral. Thus, in FIG. 6 is shown a perspective view of a connector de- vice, generally designated 1'. The connector device 1' comprises a pin element 10 identical to that described with reference to the first embodiment and attached to a radiating antenna element 20.

However, the spring clip 130 of the second embodiment differs from that of the first embodiment. The spring clip 130 comprises an upper portion 132 having a cutout portion 136 corresponding to the cut-out portion 36 of the first embodiment. Thus, it is designed to co-operate with the waist portion 14 of the pin element 10.

The upper portion 132 of the spring clip 130 extends into two legs 134a, 134b generally forming an angle α of approximately 45° with the plane of the upper portion, see FIG. 10, and having a respective end portion 135a, 135b being essentially parallel to the upper portion 132. The end portions 135a, 135b are provided with a respective protrusion 138a, 138b corresponding to the protrusion 38 of the first embodiment.

The spring clip 138 is thus provided with two well- defined contact points that can be used to establish electrical contact with an underlying substrate, such as a PCB 140, see FIGS. 8 and 9 showing a front and side view, respectively, of the connector device 1 ' connected to a PCB. In this case, the two protrusions 138a, 138b contact either a single pad or two different pads (not shown) on the PCB, depending on the application. In either case, the symmetrical configuration of the spring clip 130 ensures uniform contact pressure of the two contact points.

In the description above, the pin element 10 has been described as a self-supporting element attached to the radiating element 20. However, it is realized that it is also possible to provide a support structure or a supplementary guiding part, preferably made of plas- tics. In FIG. 11 is shown a support element, generally designated 200, used together with a connector of the kind described with reference to FIGs . 1-5. The connector is attached to an antenna element 20 mounted in an antenna carrier 210, two walls of which 212, 214 are shown in FIG. 11. The antenna carrier 210 is in turn mounted in a telephone chassis, generally designated 220.

The support element has a length slightly shorter than that of the pin element 10 and is provided with a through hole 202 with a diameter adapted for receiving the pin element 10. The support element 200 is also provided with a dovetail portion 204 adapted to cooperate with a corresponding slot in the antenna carrier 210. By means of the dovetail arrangement, the support element 200 is firmly attached to the wall 214 of the antenna carrier 210. When assembling the arrangement shown in FIG. 11, the pin element 10 is attached to the antenna element 20 in some suitable way, as has already been described above. The support element 200 is then thread onto the pin element. Finally, the spring clip 30 is attached to the pin element 10.

In an alternative embodiment, the support element is provided in two halves, see FIGs. 13 and 14. Thus, two parts 302, 304 together form a support element 300 with a shape as the one shown in FIGs. 11 and 12. The parts 302, 304 are held together by means of a pin and hole arrangement, comprising four pins provided on part 302, three of which pins 306a-c are shown in FIG. 13, arranged to cooperate with corresponding holes 308a-d in the part 304, see FIG. 14. With this alternative support element 300, the spring clip 30 can be attached to the pin element 10 before it is mounted in the support element 300.

In case a support structure as shown in FIGs. 11-14 is used, it is also possible to provide a spring clip at both end portions 16, 18 of the pin element.

Preferred embodiments of a connector according to the invention have been described. The person skilled in the art realizes that these could be varied within the scope of the appended claims. Thus, the shapes of the different parts shown in the figures can of course be adapted to different needs .

No antenna patterns have been shown in the figures but the inventive idea is applicable to radiating elements for many kinds of antennas, such as a conventional or modified PIFA, micro-strip, patch, or meander antenna.

In the embodiments described above, an antenna element is connected to a PCB of a mobile phone. It is also possible to interconnect e.g. two antenna elements by means of the inventive connector device .

In the embodiment described with reference to FIGS. 6- 10, the two legs 134a, 134b form an angle α of approximately 45° with the plane of the upper portion 132. However, it is realized that other angles are also possible, such as any angle between 15 and 75°, or more preferably between 20 and 50°.

Also, although the spring clip shown in FIGS. 1-5 has leg portions 32, 34 with a typical mutual distance "d" of about 1 millimeter, other distances are possible, such as between 0.5 and 5 millimeters , although even longer or shorter distances are possible.

Throughout this description, the term radiating element has been used. It is to be understood that this term covers any antenna element adapted to receive or transmit electromagnetic waves .

Claims

1. A connector device for use in a portable radio communication device, said connector providing electrical connection between a first object (20) and a second object (40; 140), said connector device comprising:

a conductive elongated element (10) with a longitudinal axis and having a first (16) and a second (18) end portion, wherein said elongated element is arranged to be attached to said first object (20) at said first end portion (16), and

a conductive spring element (30; 130),

characterized in that

- said spring element (30; 130) is a separate element attached to said second end portion (18) and adapted to exert a spring force directly on said second object essentially in the direction of said longitudinal axis.

2. The connector device according to claim 1, wherein said elongated element (10) is provided with a waist portion (14) at said second end portion (18).

3. The connector device according to claim 1 or 2 , wherein said spring element (30) is essentially U- shaped having a first (32) and a second (34) leg portion.

4. The connector device according to claim 3, wherein said first leg portion (32) of said spring element (30) is provided with a cut-out portion (36) adapted for receiving said waist portion (14) of said elongated element (10).

5. The connector device according to claim 3 or 4, wherein said first (32) and second (34) leg portions have a mutual distance (d) of 0.5-5 millimeters, and more preferably approximately 1 millimeter.

6. The connector device according to any of claims 3-5, wherein an outer surface of said second leg por- tion (34) is provided with a protrusion (38).

7. The connector device according to claims 6, wherein said protrusion (38) is located on said longitudinal axis of said elongated element (10).

8. The connector device according to claim 1 or 2, wherein said spring element (130) comprises two leg portions (134a, 134b) interconnected by a attachment portion (132) adapted to be attached to said elongated element ( 10) .

9. The connector device according to claim 8, wherein said attachment portion (132) is essentially planar.

10. The connector device according to claim 8 or 9, wherein said attachment portion (132) is provided with a cut-out portion (136) adapted for receiving said waist portion (14) of said elongated element (10).

11. The connector device according to any of claims 8-10, wherein said leg portions (134a, 134b) form a respective angle (α) with said attachment portion (132) of 15-75°, and preferably 20-50°.

12. The connector device according to any of claims 8-11, wherein said leg portions (134a, 134b) end in a respective end portion (135a, 135b) being essentially parallel to said attachment portion (132).

13. The connector device according to claim 12, wherein said end portions (135a, 135b) of said leg portions (134a, 134b) are provided with a respective protrusion (138a, 138b).

14. The connector device according to any of claims 1-13, comprising a support element (200; 300) supporting said elongated element (10).

15. The connector device according to any of claims 1-14, comprising an additional spring element at said first end portion (16).

16. The connector device according to any of claims 1-15, wherein one of said first (20) and second (40; 140) objects is an antenna element and the other is a printed circuit board.

17. The connector device according to any of claims 1-15, wherein said first (20) and second (40; 140) objects are antenna elements.

18. An antenna device for use in a portable radio communication device, said antenna device comprising:

an antenna element (20), a conductive elongated element (10) with a longitudinal axis and having a first (16) and a second (18) end portion, wherein said elongated element is attached to said antenna element (20) at said first end portion (16), and

a conductive spring element (30; 130),

characterized in that

said spring element (30; 130) is a separate element attached to said second end portion (18) and adapted to exert a spring force directly on an object

(40; 140) in said portable radio communication device essentially in the direction of said longitudinal axis .

19. The antenna device according to claim 17, wherein said antenna element (20) is provided on an antenna carrier (210) and said elongated element (10) is supported by a support element (200; 300) attached to said antenna carrier.

20. A portable radio communication device, com- prising a connector device (1, 1') according to any of claims 1-17 or an antenna device according to claim 18 or 19.