WO2009040613A1

WO2009040613A1 - Electrical connector and connection system

Info

Publication number: WO2009040613A1
Application number: PCT/IB2007/054342
Authority: WO
Inventors: Michel Fonteneau; Per Georg Gabrielsson; Bernardus Paagman
Original assignee: Fci
Priority date: 2007-09-28
Filing date: 2007-09-28
Publication date: 2009-04-02

Abstract

An electrical connector comprising - a housing defining an inner cavity with a top wall, a bottom wall opposite the top wall and a PCB connection opening, a receptacle (15) inside the cavity, the receptacle comprising: an electrically insulating body (23). electrical terminal members (25) in said connection region, each terminal member comprising a first portion and a second portion, the second portions projecting from the insulating body, a flexible printed circuit (29) connected to said second portions and adapted for electrically connecting the receptacle to a circuit board (2) through said PCB connection opening.

Description

ELECTRICAL CONNECTOR AND CONNECTION SYSTEM

FIELD OF THE INVENTION

The present invention relates to electrical connectors and connection systems. BACKGROUND OF THE INVENTION

In particular, the instant invention is related to an electrical connector according to the preamble of claim 1. For instance, US 6,443,768 already describes such a connector. This connector can be used in a stacked assembly as shown in Fig. 3, wherein a first connector 100 is mounted on a first upper side of a circuit board and a second connector 200 is mounted on the opposite side (lower side) of said circuit board. Insofar as these connectors are identical, it means that the first 100 and the second connector 200 are in mirror-image relationship on respective opposite sides of the circuit board. When mating connectors, for instance a transceiver module 400, are plugged into the stacked assembly, the user is required to turn up-side-down the mating connector for installing it into the second connector 200.

As a consequence, such a handling is not user- friendly. This problem is made worse when such stacked assembly is installed in a system implemented in reduced spaces such as in telecom cabinet.

An aim of the invention is to provide a connector which is can be mounted on a lower side of a circuit board and adapted to accommodate a pluggable connector without requiring an up-side-down manipulation of the pluggable connector .

A second objective is to propose a connector meeting the above-mentioned aim and which requires very few modification in respect to an existing connector. SUMMARY OF THE INVENTION

According to the invention, it is provided a connector according to claim 1.

With these features, it will be possible to use a standard receptacle while offering a connector which, as a whole, may be connected on the bottom face of a printed circuit board without changing the whole configuration of the connector and its connections and without necessitating a reverse handling of the complementary mating connector. Indeed the connection between the standard receptacle and the bottom face of the printed circuit board is transferred and realized by means of an intermediary flexible printed circuit board.

In some embodiments, one might also use one or more of the features defined in the dependent claims, considered independently or in combination.

According to an embodiment, there is provided a connector according to claim 12.

According to another embodiment, there is provided a connector according to claim 13.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages of the invention will readily appear from the following description of one of its embodiments, provided as non- limitative examples, and of the accompanying drawings. On the drawings :

Fig. 1 is a perspective exploded view of an embodiment of a connector, - Fig. 2 is a sectional view along line II-II of

Fig. 1 of the connector of Fig. 1 after connection of an opto-electric module, and

Fig. 3 is a perspective exploded view of a connector assembly according to prior art. On the different figures, the same reference signs designate like or similar elements.

DETAILED DESCRIPTION

Fig. 1 shows an exploded view of a connector 1 according to one embodiment of the invention. The connector 1 is mechanically and electrically attached to a circuit board (PCB) 2 only partially and schematically shown on Fig. 1, and for example to the bottom face of the PCB. In the present example, the connector 1 is of the small form-factor pluggable (SFP) format for use for opto- electric conversion, for example in servers, routers, storage devices, switches, optical or networking devices.

The connector 1 comprises an external cage 3 which is made from an electrically conductive material such as for example, a metallic sheet. In the present example, the cage 3 is provided in two parts, a lower part 3a and an upper part 3b defining therebetween a cavity. However, in other embodiments, the cage 3 could be designed differently. The upper part 3b comprises a top wall 4 extending longitudinally along a longitudinal axis X and from which extend two top side walls 5b and a back wall 6. Along direction X, the upper part 3b comprises a front portion 7b, an intermediate portion 8b and a rear portion 9b. At the front portion 7b, the top wall 4 comprises a latch device 10 for example formed as an elastic tongue biased so as to protrude downwardly from the top wall, and provided with a locking opening 11 for example of triangular shape. The top wall 4 and the top side walls 5b can further include openings 12, provided with spring tabs, for example obtained by partial cut-outs in the metallic sheet. These openings 12 will provide air cooling of the connector, while the spring tabs ensure shielding against electro-magnetic interferences. In the present example, the top side walls 5b extend downward to the circuit board. In the intermediate portion 8b, the top wall is provided with through openings 12 which are for example provided in three different rows and will also provide air cooling. Further, the top side walls 5b will be provided with other openings 12, as well as locking openings 13 for locking the upper part 3b of the cage to the lower part 3a.

At its rear portion 9b, the top wall 4 is stepped with respect to the top wall of the intermediate portion

8b, so that it extends further away from the circuit board, when compared to the top wall at the medium portion 8b. There, the top wall is provided with two mechanical retention through-holes 14 for mechanical retention of a receptacle 15. As well as in the intermediate portion 8b, the top side walls 5b of the rear portion 9b comprise locking openings 13.

The back wall 6 extends to the circuit board and is provided with mechanical retention posts 18 to be mechanically fixed, for example soldered, on or into the PCB 2 for connection to a grounding circuit of the circuit board.

The lower part 3a of the cage is of similar construction to the upper part 3b, and comprises a bottom wall 16 extending parallel to the top wall 4 along the longitudinal direction X, and from which extend bottom side walls 5a. The lower part 3a comprises a front portion 7a, an intermediate portion 8a and a rear portion 9a along the longitudinal direction X.

On the front portion 7a, there are no lateral bottom walls 5a, but only the bottom wall 16 which is also provided with openings 12 and spring tabs such as previously described. There is no front wall, so as to define a module opening 38 in the front of the cage 3. In the medium portion 8a and in the rear portion 9a, the external face of the lateral bottom wall 5a is provided with locking lances 17, which mechanically cooperate with the locking openings 13 of the upper part 3b of the cage for mechanically locking together the lower and the upper part of the cage. For example, upon manufacturing, the upper part 3b will be moved downward toward the lower part 3a upon which the lateral top walls 5b will deflect the locking lances 17 out of the rest position until these are inserted into the locking openings 13 in which they can resiliently deform back to their original position in which they prevent an upward movement of the upper part 3b of the cage with respect to the lower part. The herein described mechanical connection of the upper and lower cages is by way of example only.

The bottom wall 16 at the rear portion 9a does not extend up to the back wall 6, defining therebetween a PCB connection opening 37 (Figure 2). Further, an accommodating space is defined between the walls of the rear portions 9a, 9b.

At the junction between the bottom wall 16 and the bottom side walls 5a, cooling apertures 12 are also provided in the intermediate portion 8a. Other cooling apertures 12 can be provided in the bottom wall 16. Further, a plurality of mounting posts 18 extends downwardly from the bottom edges of the side walls 5a, to be mechanically fixed, for example soldered, to the printed circuit board. These posts 18 are for example cut out and bent from the metal sheet, which enables to simultaneously define a cooling aperture 12 in the bottom wall 16.

A support portion 19 is provided at said rear portions 9a, 9b. It comprises a support wall 20 which extends parallel to the top wall 4 and the bottom wall 16, and in between these walls, but does not extend up to the back wall 6 along the longitudinal direction. The support wall 20 is retained onto the cage 3 by any suitable means, such as by two lateral wings 21 which extend respectively along side each of the internal faces of the lateral bottom walls 5a. The support portion 19 is for example made in an electrically conductive material providing electromagnetic interferences shielding, and/or is a resilient material so as to permanently exert an upward force. Two resilient members (in dotted lines) 22 are provided between the support wall 20 and the bottom wall 16, for example in the form of flexible metallic tongues which would bias the inserted electro-optical module in the longitudinal direction X opposite to the transceiver module insertion direction.

The support wall 20 supports, and/or biases upward an electrical receptacle 15 which comprises an electrically insulating body 23 which defines a card receiving slot 24 in which electrical terminal members 25 extend on one or both sides of the slot 24, for electrical connection to an opto-electrical transceiver module 26 to be connected to the connector 1. As can be seen in particular in Fig. 2, each electrical terminal member 25 comprises a first portion 27 for electrical connection to the module 26, and a second portion 28 which extends in the vicinity of the top wall 4. The second portions 28 are each electrically connected to a flexible printed circuit (FPC) 29 which extends from a first connection portion 29a which extends parallel and in close proximity to the top face 4, to a second connection portion 29b which extends parallel to the back wall 6 of the cage, behind the support wall 20. Thus, the flexible printed circuit 29 is bent by about 90° between these two portions. As illustrated in the present embodiment, the electrical connection between the flexible printed circuit 29 and the printed circuit board 2 could be performed through a specific connector 30, so called FPC connector, in which the tracks on the second connection portion 29b of the flexible printed circuit 29 are electrically connected to electrical terminal members 31 which are themselves electrically connected, for example soldered, to the printed circuit board 2. The tracks of the printed circuit board 2 are adapted to mimic the connection pattern of the FPC connector. The FPC connector 30 could be mounted so as to have its connection portion floating inside an outer housing so as to allow good coplanarity with the printed circuit board 2. Upon assembly, the FPC connector 30 will first contact the circuit board 2, and then other parts of the connector such as the cage.

In another not shown embodiment, the FPC could be bent by an additional 90° so that the tracks of its second portion 29b could be directly electrically connected to the corresponding tracks of the circuit board, through the PCB- opening of the cage.

The receptacle 15 is fixed to the cage 3, for example by two pins 35 which extend upward from said body, through suitable openings in the flexible printed circuit 39 and are fixed, for example soldered, to the complementary retention through holes 14 of the top wall 4. For example, the two pins 35 have different geometries. As is shown schematically on Fig. 2, which is upside-down with respect to Fig. 1 so as to show the connector as it is installed on the bottom face of the PCB in the electrical device, the opto-electrical transceiver module 26 extends into the cavity inside the cage 3, after having been inserted there through the module opening. Upon insertion, the module is introduced along longitudinal direction X, against the bias of the resilient member 22 onto its end 26a, until its latching part 32 will be introduced into the locking opening 11 of the top wall 4 of the upper part 3b of the cage. In this position, an electrical connection part 33 of the module 26 is inserted into the slot 24 of the receptacle 15. The electrical connection part 33 is for example a part of a printed circuit board comprising tracks which are electrically connected to the electrical terminal members 25. Due to the position of the receptacle 15 inside the cavity and the shape of the module 26, insertion of the module 26, without calling for reverse manipulation of it, in the connector 1 is only possible with the correct orientation but. The module 26 further comprises a connection portion schematically shown as 34 for connection to a suitable complementary mating connector schematically shown as 36, for example such as a RJ 45 plug.

The embodiment which has just been described enables to use pre-existing elements, such as the cage, the card receiving portion of the receptacle, with very few modifications, to provide with a reverse-mated SFP connector. The use of pre-existing compounds allows not to define an entirely new connector, which would require extensive development and validation work but to use preexisting components for providing the function of a reverse-mated SFP connector.

It should be appreciated by the skilled person that, although the description refers to a SFP connector, the inventive concept could be used for other connectors as long as it is necessary to provide a connector adapted to be mounted on a circuit board and in which a mating connector has to be inserted in its "usual" orientation, and not in "up-side-down" arrangement.

Claims

1. An electrical connector comprising:

- a housing defining an inner cavity with a top wall, a bottom wall opposite the top wall and a circuit board connection opening, a receptacle (15) inside the cavity, the receptacle comprising: an electrically insulating body (23) . electrical terminal members (25) in said connection region, each terminal member comprising a first portion and a second portion, the second portions projecting from the insulating body, a flexible printed circuit (29) connected to said second portions and adapted for electrically connecting the receptacle to a circuit board (2) through said circuit board connection opening.

2. A connector according to claim 1, wherein the housing comprises an outer cage (3) made in an electrically conducting material and defining the inner cavity and comprising the bottom wall (16), the top wall (4) and the circuit board connection opening, the bottom wall being adapted to be fixed to the printed circuit board.

3. A connector according to claim 2, wherein said second portions project from the insulating body toward the top wall.

4. A connector according to any preceding claim, wherein the second portions of the electrical terminal members are adapted for electrical connection to an opto- electrical transceiver module (26).

5. A connector according to any preceding claim further comprising a support wall (20) extending between said top and bottom walls, parallel to said top and bottom walls, and supporting said receptacle.

6. A connector according to claim 5, wherein the support wall (20) is adapted to resiliently urge the receptacle (15) toward the top wall.

7. A connector according to claim 4, wherein said top wall comprises a latch device (11) for mechanical connection to said transceiver module.

8. A connector according to any preceding claim, further comprising an FPC connector (30) for electrically connecting the flexible printed circuit (29) to the circuit board (2) .

9. A connector according to any preceding claim 1 to 7, wherein said flexible printed circuit (29) extends between a first connection portion for connection to said second portions of said electrical terminal members and a second connection portion for connection to said circuit board, wherein the flexible printed circuit is bent by at least about 90°.

10. A connector according to any preceding claim, wherein said receptacle is mechanically attached to the top wall of the cage.

11. A connector according to any preceding claim wherein said top wall comprises at least a first portion

(7b, 8b) and a second portion (9b) stepping from said first portion away from said bottom wall, to provide an accommodating space for said receptacle (15) below said second portion.

12. A connector comprising: an outer cage (3) made in an electrically conducting material and defining an inner cavity, said cage comprising a bottom wall (16) adapted to be fixed to a circuit board, and a top wall (4) opposite said bottom wall, said cage comprising a circuit board connection opening, a receptacle (15) inside said cavity, the receptacle comprising: . an electrically insulating body (23) defining a connection region (24), electrical terminal members (25) in said connection region, each terminal member comprising a first portion and a second portion, said first portion being adapted for electrical connection to an opto-electrical transceiver module (26), said second portion projecting from the insulating body toward the top wall, a flexible printed circuit (29) connected to said second portions and adapted for electrically connecting the receptacle to the circuit board (2) through said PCB connection opening,

- an FPC connector (30) for electrically connecting the flexible printed circuit (29), to the printed circuit board (2) .

13. A connector comprising: an outer cage (3) made in an electrically conducting material and defining an inner cavity, said cage comprising a bottom wall (16) adapted to be fixed to a circuit board, and a top wall (4) opposite said bottom wall, said cage comprising a PCB-connection opening, a receptacle (15) inside said cavity, the receptacle comprising: an electrically insulating body (23) defining a connection region (24), electrical terminal members (25) in said connection region, each terminal member comprising a first portion and a second portion, said first portion being adapted for electrical connection to an opto-electrical transceiver module (26), said second portion projecting from the insulating body toward the top wall, a flexible printed circuit (29) connected to said second portions and adapted for electrically connecting the receptacle to the circuit board (2) through said PCB connection opening, wherein said top wall (4) comprises a latch device (11) for mechanical connection to said transceiver module, wherein said cage comprises resilient members (32) adapted to bias said opto-electrical transceiver module into locking engagement with said latch device (11), said resilient members being provided between said support wall (20) and said bottom wall (16) .