Cable connection structure and cable connector including same

This application claims the benefit of Japanese Patent Application No. 2015-016108, filed Jan. 29, 2015, which is hereby incorporated by reference herein in its entirety.

The present invention relates to a cable connection structure and a cable connector including the same.

In an optical communication system, a transceiver module is put into practical use in order to transmit an optical signal, which is transmitted through an optical connector and the like, to a mother board. As disclosed in Japanese Patent No. 5573651, for example, the transceiver module comprises the following components in a housing as its main elements, namely: a transmitting optical sub-assembly (hereinafter also referred to as TOSA), a receiving optical sub-assembly (hereinafter also referred to as ROSA), a first circuit board and a second circuit board configured to perform signal processing, control, and the like for the TOSA and the ROSA, and a connector portion electrically connecting the first circuit board as well as the second circuit board to a host device.

The electrical connection between the TOSA and the first circuit board, and the electrical connection between the ROSA and the first circuit board are connected by using flexible boards, respectively. The electrical connection between the first circuit board and the second circuit board is also connected by using a flexible board.

In some cases, connecting work of connection terminals of the TOSA and the ROSA as well as connection terminals of the first circuit board and the second circuit board to connection end portions of the above-mentioned flexible boards may be carried out manually by an expert on soldering work, because quality of connection at the connection end portions of the flexible boards may adversely affect signal characteristics of the transceiver module when a communication speed (transfer efficiency) in the transceiver module is relatively high.

However, when the connecting work of the connection terminals of the first circuit board and the second circuit board and the like to the connection end portions of the flexible boards in the above-described transceiver module is carried out in the soldering work by hand, quality of the signal characteristics of the transceiver module may become unstable due to variation in work quality. In particular, when the transmission speed in the transceiver module is 25 Gbps or more, such variation in work quality may adversely affect the signal characteristics of the transceiver module.

In view of the above-described problem, the present invention aims to provide a cable connection structure and a cable connector including the same. The cable connection structure and a cable connector including the same can stabilize work quality in connecting a connection end portion of a flexible board to a circuit board, and maintain high quality in signal characteristics of a transceiver module even when a communication speed in the transceiver module is relatively high.

To achieve the above-described object, a cable connection structure according to the present invention comprises: a connection end portion of a flexible cable, the flexible cable having a group of contact pads formed at least at one ends of a plurality of signal lines configured to transmit a signal and one ends of a plurality of ground lines to be grounded, a ground plate electrically connected to the plurality of ground lines with respect to the contact pads, and a reinforcing plate provided on a surface of the ground plate with respect to the contact pads, the connection end portion which the ground plate and the reinforcing plate are oppositely joined to the group of contact pads; and a plurality of contact terminals each having a contact portion to come into contact with a corresponding one of the contact pads, the contact terminals being configured to electrically connect the connection end portion of the cable to a wiring board. The ground plate may have a plurality of extension portions formed at a given interval along a direction of arrangement of the contact terminals. In addition, a ground plate piece to be electrically connected to the ground line may further be formed between the extension portions adjacent to each other. Moreover, a plurality of ground plate pieces to be electrically connected to the ground lines may further be formed away from the ground plate and disposed at a given interval along the direction of arrangement of the contact terminals.

A cable connector according to the present invention comprises: the above-described cable connection structure; a cable end portion accommodating portion configured to detachably accommodate the connection end portion of the cable; and a cable holding means provided to the cable end portion accommodating portion, and configured to press the connection end portion of the cable against the contact portions of the contact terminals and to thus detachably hold the connection end portion on the cable end portion accommodating portion. Additionally, the cable connector may further include a conductive connection member provided to the cable end portion accommodating portion and configured to come into contact with fixed portions of the plurality of contact terminals electrically connected to ground line conductive layers of the cable to be connected. The reinforcing plate may be made of a conductive resin material.

The cable connection structure and the cable connector including the same according to the present invention comprise: the connection end portion of the flexible cable that is provided with a group of contact pads formed at least at one ends of a plurality of signal lines configured to transmit a signal and one ends of a plurality of ground lines to be grounded, the ground plate electrically connected to the plurality of ground lines with respect to the contact pads, and the reinforcing plate provided on the surface of the ground plate with respect to the contact pads, the connection end portion being configured to join the ground plate and the reinforcing plate to the group of contact pads while locating the ground plate and the reinforcing plate opposite to the group of contact pads; and the plurality of contact terminals each having the contact portion to come into contact with the corresponding one of the group of contact pads, the contact terminals being configured to electrically connect the connection end portion of the cable to the wiring board. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to a circuit board, and to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

FIG. 1 is a perspective view showing a first embodiment of a cable connection structure according to the present invention together with substantial part of a cable connector;

FIG. 2 is a perspective view showing a first embodiment of the cable connection structure according to the present invention together with the substantial part of the cable connector fixed to a printed circuit board;

FIG. 3 is a partial cross-sectional view taken along a III-III line in FIG. 1 ;

FIG. 4 is a perspective view showing external appearance of an example of the cable connector according to the present invention;

FIG. 5 is a perspective view showing a second embodiment of a cable connection structure according to the present invention together with substantial part of a cable connector;

FIG. 6 is a perspective view showing a third embodiment of a cable connection structure according to the present invention together with substantial part of a cable connector;

FIG. 7 is a perspective view showing a fourth embodiment of a cable connection structure according to the present invention together with substantial part of a cable connector;

FIG. 8 is a perspective view showing a fifth embodiment of a cable connection structure according to the present invention together with substantial part of a cable connector;

FIG. 9 is a characteristic diagram showing characteristic lines which represent characteristics of crosstalk in each embodiment of the cable connection structures according to the present invention;

FIG. 10 is a characteristic diagram showing characteristic lines which represent characteristics of insertion losses in each embodiment of the cable connection structures according to the present invention;

FIG. 11 is a perspective view showing external appearance of an example of the cable connector using another example of contact terminals and being applied in each embodiment of the cable connection structures according to the present invention;

FIG. 12 is a perspective view showing a state where a flexible board is connected in the example shown in FIG. 11 ;

FIG. 13 is another perspective view showing the state where the flexible board is connected in the example shown in FIG. 11 ;

FIG. 14 is a partial cross-sectional view taken along a XIV-XIV line in FIG. 12 ;

FIG. 15 is an enlarged partial view showing an enlarged part illustrated in FIG. 13 ;

FIG. 16 is a perspective view showing another example of the contact terminal;

FIG. 17 is a perspective view showing external appearance of still another example of the cable connector to which each embodiment of the cable connection structures according to the present invention are applied;

FIG. 18 is a cross-sectional view taken along a XVIII-XVIII line in FIG. 17 ;

FIG. 19 is a perspective view showing a conductive block unit to be used in the example shown in FIG. 17 ;

FIG. 20 is a perspective view showing a cable connector including a variation of the conductive block unit;

FIG. 21 is a cross-sectional view taken along a XXI-XXI line in FIG. 20 ; and

FIG. 22 is a perspective view showing external appearance of yet another example of the cable connector to which each embodiment of the cable connection structures according to the present invention are applied.

FIG. 2 shows a cable connector, to which a first embodiment of a cable connection structure according to the present invention is applied, together with a printed circuit board.

As shown in FIG. 3 , for example, a printed circuit board 24 is formed into a multilayer structure which comprises a first board 24 A, a second board 24 B, and a third board 24 C. The second board 24 B is stacked on an upper surface of the third board 24 C. The first board 24 A is also stacked on an upper surface of the second board 24 B. A conductive layer of the first board 24 A and a conductive layer of the second board 24 B are electrically connected to each other through a plurality of vias 26 ai (i=1 to n, n is a positive integer).

For example, a signal processing circuit which includes, among other things, an electronic device (not shown) and the like configured to convert optical signals that are supplied from a receiving optical sub-assembly (hereinafter also referred to as an ROSA) through a flexible board 10 and contact terminals 32 ai (i=1 to 13) of a cable connector 30 to be described later into electric signals, is formed on a mounting surface of the first board 24 A of the printed circuit board 24 . The signal processing circuit is connected to one end of each of a plurality of signal layers 24 S and a plurality of ground layers 24 G (see FIG. 2 ) formed on the mounting surface of the first board 24 A. Moreover, the signal processing circuit is electrically connected to a connector which is configured to send out formed electric signals to the outside. It is to be noted that, although another end of the flexible board 10 is connected to the ROSA in this example, the present invention is not limited to this example and the other end of the flexible board 10 may be connected to a TOSA (transmitting optical sub-assembly).

The plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A extend parallel to an X coordinate axis in the Cartesian coordinates shown in FIG. 2 , i.e., along a longitudinal direction of the printed circuit board 24 , respectively. Here, as shown in FIG. 2 , the plurality of signal layers 24 S and the plurality of ground layers 24 G are formed sequentially from one end to the other end of the printed circuit board 24 at given intervals along a Y coordinate axis in the order of a ground layer 24 G, a signal layer 24 S, another signal layer 24 S, and another ground layer 24 G, and so on. Note that FIG. 2 representatively illustrates some of the ground layers 24 G and the signal layers 24 S of the printed circuit board 24 .

Another end of each of the plurality of signal layers 24 S and of the plurality of ground layers 24 G is connected to a fixed terminal portion 32 F of the corresponding one of the contact terminals 32 ai of the cable connector 30 (see FIG. 3 ). Note that FIG. 2 representatively illustrates part of the cable connector 30 .

As shown in FIG. 4 , connection end portions 15 of two flexible boards 10 , for example, are to be connected to the cable connector 30 , respectively. The cable connector 30 is fixed to an end portion of the mounting surface of the first board 24 A. The cable connector 30 includes, as its main elements: a pair of cable end portion accommodating portions 30 A into which the connection end portions 15 on one side of the flexible boards 10 are detachably inserted, respectively; the contact terminals 32 ai (see FIG. 5 ) configured to electrically connect the connection end portions 15 on the one side of the flexible boards 10 to the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and a pair of lever members 34 configured to press the connection end portions on the one side of the flexible boards 10 , which are inserted into the cable end portion accommodating portions 30 A, against contact portions of the plurality of contact terminals 32 ai and to hold the connection end portions 15 thereon.

One of the pair of cable end portion accommodating portions 30 A is formed by being surrounded by a side wall 30 RW, a middle wall 30 MW, a back wall 30 BW, and a bottom wall, which collectively constitute a housing. The other cable end portion accommodating portion 30 A is formed by being surrounded by a side wall 30 LW, the middle wall 30 MW, the aforementioned back wall 30 BW, and the aforementioned bottom wall, which collectively constitute a housing. Each cable end portion accommodating portion 30 A has a cable insertion slot which is opened in a direction of extension of the printed circuit board 24 . Each cable end portion accommodating portion 30 A includes a plurality of slits 30 Si (i=1 to n, n is the positive integer) in which the contact terminals 32 ai are arranged. The plurality of slits 30 Si are formed at given intervals along the Y coordinate axis in FIG. 2 . The slits 30 Si penetrate the back wall 30 BW as shown in FIG. 3 . Every adjacent slits 30 Si are separated from each other by a corresponding one of partition walls 30 Pi (i=1 to n, n is the positive integer).

The lever members 34 serving as cable holding means are turnably provided above the cable end portion accommodating portions 30 A, respectively. Support shafts 34 S formed on two ends of one of the lever members 34 , respectively, are inserted into a hole 30 a in the side wall 30 RW and a hole (not shown) in the middle wall 30 MW. Support shafts 34 S formed on two ends of the other lever member 34 , respectively, are inserted into a hole 30 a in the side wall 30 LW and the hole (not shown) in the middle wall 30 MW. In the case where the flexible board 10 is attached to the cable connector 30 having the above-described configuration, the area of an opening of the cable insertion slot becomes largest when each lever member 34 is turned in a direction indicated with an arrow in FIG. 4 . Hence, the connection end portion 15 on the one side of the flexible board 10 is inserted into the insertion slot. Thereafter, the lever member 34 is turned in a direction opposite to the direction indicated with the arrow in FIG. 4 until tabs of the lever member 34 are inserted into a groove 30 G in the side wall 30 RW or 30 LW and into a groove 30 G in the middle wall 30 MW. Thus, a pressing surface of the lever member 34 presses the connection end portion 15 on the one side of the flexible board 10 against contact portions 32 C of the plurality of contact terminals 32 ai , and the contact end portion 15 is held in the corresponding cable end portion accommodating portion (see FIG. 3 ).

As shown in FIG. 3 , the contact terminals 32 ai are made of a thin-plate metal material, for example, and include: the contact portions 32 C to come into contact with contact pads (hereinafter also referred to as conductive layers) 22 ai (i=1 to n, n is the positive integer) of the connection end portion 15 on the one side of the flexible board 10 ; the fixed terminal portions 32 F to be soldered and fixed to the end portions of the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and movable pieces 32 M to couple the contact portions 32 C to the fixed terminal portions 32 F.

Each contact portion 32 C is bent into an arc shape such that its tip end is directed to the fixed terminal portion 32 F. The fixed terminal portion 32 F projects from an open end portion of the slit 30 Si that is adjacent to the cable insertion slot toward the first board 24 A. As shown in FIG. 3 , the movable piece 32 M extends to the back wall 30 BW and is bent substantially into a U-shape.

As shown in FIG. 1 and FIG. 3 , the flexible board 10 has a configuration in which a conductive body 20 including a plurality of conductive layers 22 ai (i=1 to n, n is the positive integer) each covered with a protection layer, for example, is formed on a surface 16 B of an insulative base material 16 opposed to the contact portions 32 C of the contact terminals 32 ai . The protection layer is made of a thermosetting resist layer or a polyimide film, for example. The insulative base material 16 is molded of a liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), or polyetherimide (PEI), for example. In addition, each conductive layer 22 ai is formed from layers of a copper alloy, for example. A contact pad is formed at a section at one end of each conductive layer 22 ai corresponding to the connection end portion of the flexible board 10 , the section being designed to come into contact with the contact portion 32 C of the contact terminal 32 ai . The conductive layers 22 ai include a ground line conductive layer (G), a signal line conductive layer (S), another signal line conductive layer (S), another ground line conductive layer (G), and so forth which are arranged sequentially from one end in FIG. 1 .

As shown in an enlarged manner in FIG. 1 , a ground plate 12 having a predetermined length is fixed to a surface 16 A of the insulative base material 16 located opposite from the surface 16 B. Extension portions 12 b are formed like teeth of a comb, respectively, at portions of the ground plate 12 which are located immediately above contact pads of the above-described ground line conductive layers (G). The ground line conductive layers (G) out of the conductive layers 22 ai and the extension portions 12 b are electrically connected to one another through vias 18 ai (i=1 to n, n is the positive integer).

A clearance 12 a is formed between every two extension portions 12 b that are adjacent to each other at a given interval. Two signal line conductive layers (S) out of the conductive layers 22 ai are formed at a position immediately below each clearance 12 a of the ground plate 12 . Moreover, in FIG. 1 , a cutout portion 12 c is formed adjacent to each endmost extension portion 12 b of the ground plate 12 .

A rectangular reinforcing plate 14 molded of a conductive resin material, for example, is fixed to part of an upper surface of the ground plate 12 . Electric conductivity (conductance) of the conductive resin material being an antistatic resin material is set in a range from 1 S/m to 30000 S/m inclusive, for example.

An end surface at one end of the reinforcing plate 14 and an end surface at one end of the insulative base material 16 are located on a common plane. Accordingly, the extension portions 12 b of the ground plate 12 is set to the same electric potential as that of the ground line conductive layers (G). Note that the reinforcing plate 14 is not limited to the above-described example, and may be formed by cutting the conductive resin material, for instance. The reinforcing plate 14 may be molded of a glass epoxy, polyimide, polyethylene terephthalate materials or the like.

When the flexible board 10 is connected to the cable connector 30 in the above-described configuration, the lever member 34 is turned in the direction indicated with the arrow in FIG. 4 , and the connection end portion on the one side of the flexible board 10 is inserted through the cable insertion slot and located at a predetermined position. Then, the lever member 34 is turned in the direction opposite to the direction indicated with the arrow in FIG. 4 until the tabs of the lever member 34 are inserted into the grooves 30 G. Thus, the pressing surface of the lever member 34 presses the connection end portion on the one side of the flexible board 10 against the contact portions 32 C of the plurality of contact terminals 32 ai , and the contact end portion is held thereon. On the other hand, when the flexible board 10 is detached from the cable connector 30 , the lever member 34 is turned in the direction indicated with the arrow in FIG. 4 , and the connection end portion on the one side of the flexible board 10 is pulled out and thus detached from the cable connector 30 .

Accordingly, in the above-described configuration, the connection end portion on the one side of the flexible board 10 can be electrically connected to the printed circuit board 24 without requiring any soldering work. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to the circuit board. In addition, the extension portions 12 b of the ground plate 12 are set to the same electric potential as that of the ground line conductive layers (G). Thus, it is possible to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

FIG. 5 shows substantial part of a cable connector, to which a cable connection structure according to a second embodiment of the present invention is applied, together with the printed circuit board.

In the example shown in FIG. 1 , the clearance 12 a is formed between every two extension portions 12 b of the ground plate 12 which are adjacent to each other at a given interval. On the other hand, in an example shown in FIG. 5 , a ground plate piece 42 C is additionally provided between extension portions 42 b of a ground plate 42 of a flexible board 40 . A cable connector has a configuration similar to that of the cable connector 30 shown in FIG. 4 .

Note that constituents in FIG. 5 which are the same as the constituents in the example shown in FIG. 1 will be designated by the same reference numerals and overlapping description thereof will be omitted.

As shown in FIG. 5 , the flexible board 40 has a configuration in which a conductive body including a plurality of conductive layers each covered with a protection layer, for example, is formed on a surface of an insulative base material 46 opposed to the contact portions 32 C of the contact terminals 32 ai . The protection layer is made of a thermosetting resist layer or a polyimide film, for example. The insulative base material 46 is molded of a liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), or polyetherimide (PEI), for example. In addition, each of the above-described conductive layers is formed from layers of a copper alloy, for example. A contact pad is formed at a section at one end of each conductive layer corresponding to a connection end portion of the flexible board 40 , the section being designed to come into contact with the contact portion 32 C of the contact terminal 32 ai . The conductive layers include a ground line conductive layer (G), a signal line conductive layer (S), another signal line conductive layer (S), another ground line conductive layer (G), and so forth which are arranged sequentially from one end.

A ground plate 42 having a predetermined length is fixed to a surface of the insulative base material 46 located opposite from the aforementioned surface. The substantially rectangular ground plate pieces 42 C are provided at given intervals on a common plane, respectively, at portions of the ground plate 42 which are located immediately above contact pads of the above-described ground line conductive layers (G). In addition, extension portions 42 b extending from an end of the ground plate 42 to an end of the insulative base material 46 are formed at given intervals like teeth of a comb at spaces between the adjacent ground plate pieces 42 C. The ground line conductive layers (G) out of the conductive layers, the ground plate pieces 42 C, and the ground plate 42 are electrically connected to one another through vias 48 ai.

Two signal line conductive layers (S) out of the conductive layers are formed at a position immediately below each extension portion 42 b of the ground plate 42 .

A rectangular reinforcing plate 44 molded of a conductive resin material, for example, is fixed to part of an upper surface of the ground plate 42 . Electric conductivity of the conductive resin material being an antistatic resin material is set in a range from 1 S/m to 30000 S/m inclusive, for example. An end surface at one end of the reinforcing plate 44 and an end surface at one end of the insulative base material 46 are located on a common plane. Accordingly, the extension portions 42 b of the ground plate 42 and the ground plate pieces 42 C are set to the same electric potential as that of the ground line conductive layers (G). Note that the reinforcing plate 44 is not limited to the above-described example, and may be formed by cutting the conductive resin material, for instance. The reinforcing plate 44 may be molded of a glass epoxy, polyimide, polyethylene terephthalate materials or the like.

Accordingly, in the above-described configuration as well, the connection end portion on the one side of the flexible board 40 can be electrically connected to the printed circuit board 24 without requiring any soldering work. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to the circuit board. In addition, the extension portions 42 b of the ground plate 42 and the ground plate pieces 42 C are set to the same electric potential as that of the ground line conductive layers (G). Thus, it is possible to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

FIG. 6 shows substantial part of a cable connector, to which a cable connection structure according to a third embodiment of the present invention is applied, together with the printed circuit board.

In the example shown in FIG. 1 , the extension portions 12 b of the ground plate 12 of the flexible board 10 , which are adjacent at the given intervals, are formed integrally with the remaining portion of the ground plate 12 . On the other hand, in an example shown in FIG. 6 , ground plate pieces 52 C are provided on a common plane, respectively, at portions of a ground plate 52 of a flexible board 50 which are located immediately above contact pads of ground line conductive layers (G), while having a given interval with the ground plate 52 .

A cable connector has a configuration similar to that of the cable connector 30 shown in FIG. 4 .

Note that constituents in FIG. 6 which are the same as the constituents in the example shown in FIG. 1 will be designated by the same reference numerals and overlapping description thereof will be omitted.

As shown in FIG. 6 , the flexible board 50 has a configuration in which a conductive body including conductive layers each covered with a protection layer, for example, is formed on a surface of an insulative base material 56 opposed to the contact portions 32 C of the contact terminals 32 ai . The protection layer is made of a thermosetting resist layer or a polyimide film, for example. The insulative base material 56 is molded of a liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), or polyetherimide (PEI), for example. In addition, each of the above-described conductive layers is formed from layers of a copper alloy, for example. A contact pad is formed at a section at one end of each conductive layer corresponding to a connection end portion of the flexible board 50 , the section being designed to come into contact with the contact portion 32 C of the contact terminal 32 ai . The conductive layers include a ground line conductive layer (G), a signal line conductive layer (S), another signal line conductive layer (S), another ground line conductive layer (G), and so forth which are arranged sequentially from one end.

The ground plate 52 having a predetermined length is fixed to a surface of the insulative base material 56 located opposite from the aforementioned surface. The substantially rectangular ground plate pieces 52 C are provided at given intervals on a common plane, respectively, at portions which are located away from an end of the ground plate 52 by the given interval and immediately above contact pads of the above-described ground line conductive layers (G). The ground line conductive layers (G) out of the conductive layers, the ground plate pieces 52 C, and the ground plate 52 are electrically connected to one another through vias 58 ai (i=1 to n, n is the positive integer).

Two signal line conductive layers (S) out of the conductive layers are formed at a position immediately below each space between the ground plate pieces 52 C.

A rectangular reinforcing plate 54 molded of a conductive resin material, for example, is fixed to part of an upper surface of the ground plate 52 . Electric conductivity of the conductive resin material being an antistatic resin material is set in a range from 1 S/m to 30000 S/m inclusive, for example. An end surface at one end of the reinforcing plate 54 and an end surface at one end of the insulative base material 56 are located on a common plane. Accordingly, the ground plate 52 and the ground plate pieces 52 C are set to the same electric potential as that of the ground line conductive layers (G). Note that the reinforcing plate 54 is not limited to the above-described example, and may be formed by cutting the conductive resin material, for instance.

The reinforcing plate 54 may be molded of a glass epoxy, polyimide, polyethylene terephthalate materials or the like.

Accordingly, in the above-described configuration as well, the connection end portion on the one side of the flexible board 50 can be electrically connected to the printed circuit board 24 without requiring any soldering work. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to the circuit board. In addition, the ground plate 52 and the ground plate pieces 52 C are set to the same electric potential as that of the ground line conductive layers (G). Thus, it is possible to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

FIG. 7 shows substantial part of a cable connector, to which a cable connection structure according to a fourth embodiment of the present invention is applied, together with the printed circuit board.

In the example shown in FIG. 1 , the plurality of extension portions 12 b of the ground plate 12 of the flexible board 10 are formed at the given intervals. On the other hand, in an example shown in FIG. 7 , a second ground plate 62 C extending along the arrangement of the contact terminals 32 ai is formed on a common plane while having a given interval with a first ground plate 62 of a flexible board 60 .

A cable connector has a configuration similar to that of the cable connector 30 shown in FIG. 4 .

Note that constituents in FIG. 7 which are the same as the constituents in the example shown in FIG. 1 will be designated by the same reference numerals and overlapping description thereof will be omitted.

As shown in FIG. 7 , the flexible board 60 has a configuration in which a conductive body including conductive layers each covered with a protection layer, for example, is formed on a surface of an insulative base material 66 opposed to the contact portions 32 C of the contact terminals 32 ai . The protection layer is made of a thermosetting resist layer or a polyimide film, for example. The insulative base material 66 is molded of a liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), or polyetherimide (PEI), for example. In addition, each of the above-described conductive layers is formed from layers of a copper alloy, for example. A contact pad is formed at a section at one end of each conductive layer corresponding to a connection end portion of the flexible board 60 , the section being designed to come into contact with the contact portion 32 C of the contact terminal 32 ai . The conductive layers include a ground line conductive layer (G), a signal line conductive layer (S), another signal line conductive layer (S), another ground line conductive layer (G), and so forth which are arranged sequentially from one end.

The first ground plate 62 having a predetermined length is fixed to a surface of the insulative base material 66 located opposite from the aforementioned surface. The substantially rectangular second ground plate 62 C extending in the direction of the arrangement of the ground line conductive layers (G) and the signal line conductive layers (S) described above is provided on a common plane at a position away from an end of the first ground plate 62 by the given interval. A length dimension and a width dimension of the second ground plate 62 C in terms of the direction of arrangement of the ground line conductive layers (G) and the signal line conductive layers (S) described above are set smaller than a length dimension and a width dimension of the first ground plate 62 .

The ground line conductive layers (G) out of the conductive layers, the first ground plate 62 , and the second ground plate 62 C of the flexible board 60 are electrically connected to one another through vias 68 ai (i=1 to n, n is the positive integer).

A rectangular reinforcing plate 64 molded of a conductive resin material, for example, is fixed to part of an upper surface of the first ground plate 52 and to an upper surface of the second ground plate 62 C. Electric conductivity of the conductive resin material being an antistatic resin material is set in a range from 1 S/m to 30000 S/m inclusive, for example. An end surface at one end of the reinforcing plate 64 and an end surface at one end of the insulative base material 66 are located on a common plane. Accordingly, the first ground plate 62 and the second ground plate 62 C are set to the same electric potential as that of the ground line conductive layers (G). Note that the reinforcing plate 64 is not limited to the above-described example, and may be formed by cutting the conductive resin material, for instance. The reinforcing plate 64 may be molded of a glass epoxy, polyimide, polyethylene terephthalate materials or the like.

Accordingly, in the above-described configuration as well, the connection end portion on the one side of the flexible board 60 can be electrically connected to the printed circuit board 24 without requiring any soldering work. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to the circuit board. In addition, the first ground plate 62 and the second ground plate 62 C are set to the same electric potential as that of the ground line conductive layers (G). Thus, it is possible to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

FIG. 8 shows substantial part of a cable connector, to which a cable connection structure according to a fifth embodiment of the present invention is applied, together with the printed circuit board.

In the example shown in FIG. 1 , the plurality of extension portions 12 b of the ground plate 12 of the flexible board 10 are formed to the extent that the tip ends thereof do not reach the end surface of the insulative base material 16 . On the other hand, in an example shown in FIG. 8 , a ground plate 72 is provided on the entire surface at an end portion of an insulative base material 76 corresponding to a connection end portion of a flexible board 70 .

A cable connector has a configuration similar to that of the cable connector 30 shown in FIG. 4 .

Note that constituents in FIG. 8 which are the same as the constituents in the example shown in FIG. 1 will be designated by the same reference numerals and overlapping description thereof will be omitted.

As shown in FIG. 8 , the flexible board 70 has a configuration in which a conductive body including a plurality of conductive layers each covered with a protection layer, for example, is formed on a surface of the insulative base material 76 opposed to the contact portions 32 C of the contact terminals 32 ai . The protection layer is made of a thermosetting resist layer or a polyimide film, for example. The insulative base material 76 is molded of a liquid crystal polymer, polyimide (PI), polyethylene terephthalate (PET), or polyetherimide (PEI), for example. In addition, each of the above-described conductive layers is formed from layers of a copper alloy, for example. A contact pad is formed at a section at one end of each conductive layer corresponding to a connection end portion of the flexible board 70 , the section being designed to come into contact with the contact portion 32 C of the contact terminal 32 ai . The conductive layers include a ground line conductive layer (G), a signal line conductive layer (S), another signal line conductive layer (S), another ground line conductive layer (G), and so forth which are arranged sequentially from one end.

The ground plate 72 having a predetermined length is fixed to a surface of the insulative base material 76 located opposite from the aforementioned surface. As shown in FIG. 8 , the ground plate 72 extends to the end portion on one side of the insulative base material 76 .

The ground line conductive layers (G) out of the conductive layers, and ground plate 72 of the flexible board 70 are electrically connected to one another through vias 78 ai (i=1 to n, n is the positive integer).

As shown in FIG. 8 , a rectangular reinforcing plate 74 molded of a conductive resin material, for example, is fixed to part of an upper surface of the ground plate 72 . Electric conductivity of the conductive resin material being an antistatic resin material is set in a range from 1 S/m to 30000 S/m inclusive, for example. An end surface at one end of the reinforcing plate 74 and an end surface at one end of the insulative base material 76 are located on a common plane. Accordingly, the ground plate 72 and the ground line contact terminals 32 ai are set to the same electric potential as that of the ground line conductive layers (G). Note that the reinforcing plate 74 is not limited to the above-described example, and may be formed by cutting the conductive resin material, for instance. The reinforcing plate 74 may be molded of a glass epoxy, polyimide, polyethylene terephthalate materials or the like.

Accordingly, in the above-described configuration as well, the connection end portion on the one side of the flexible board 70 can be electrically connected to the printed circuit board 24 without requiring any soldering work. Thus, it is possible to stabilize work quality in connecting the connection end portion of the flexible board to the circuit board. In addition, the ground plate 72 and the ground line contact terminals 32 ai are set to the same electric potential as that of the ground line conductive layers (G). Thus, it is possible to maintain high quality in signal characteristics of a transceiver module when a communication speed in the transceiver module becomes relatively high.

The inventor of the present application has conducted comparative verification concerning characteristics of insertion losses and crosstalk in the cable connection structures according to the above-described first to fifth embodiments of the present invention by use of a given simulator system.

FIG. 9 represents characteristics of crosstalk (far-end crosstalk) when a given signal is transmitted from the respective flexible boards described above, in which the vertical axis indicates the crosstalk (dB) and the horizontal axis indicates the frequency (GHz). Characteristic lines L 1 , L 2 , L 3 , L 4 , and L 5 show characteristics of crosstalk of the second embodiment (see FIG. 5 ), the third embodiment (see FIG. 6 ), the first embodiment (see FIG. 1 ), the fourth embodiment (see FIG. 7 ), and the fifth embodiment (see FIG. 8 ), respectively.

As apparent from the characteristic lines L 1 , L 2 , and L 3 in FIG. 9 , in a frequency range of 20 GHz to 25 GHz, for example, stable and fine characteristic results with no ripples were achieved in the order of the characteristic lines L 1 (the second embodiment), L 3 (the first embodiment), and L 2 (the third embodiment).

FIG. 10 represents characteristics of insertion losses when a given signal is transmitted from the respective flexible boards described above, in which the vertical axis indicates the insertion loss (dB) and the horizontal axis indicates the frequency (GHz). Characteristic lines L 1 , L 2 , L 3 , L 4 , and L 5 show characteristics of insertion losses of the second embodiment (see FIG. 5 ), the third embodiment (see FIG. 6 ), the first embodiment (see FIG. 1 ), the fourth embodiment (see FIG. 7 ), and the fifth embodiment (see FIG. 8 ), respectively.

As apparent from the characteristic lines L 1 , L 2 , and L 3 in FIG. 10 , in the frequency range of 20 GHz to 25 GHz, for example, stable and fine characteristic results with no ripples were achieved in the order of the characteristic lines L 3 (the first embodiment), L 2 (the third embodiment), and L 1 (the second embodiment).

FIG. 11 shows external appearance of another example of the cable connector to which the above-described cable connection structures according to the embodiments of the present invention are applied.

The fixed terminal portions 32 F of the contact terminals 32 ai used in the cable connector shown in FIG. 4 project from the open end portions of the slits 30 Si adjacent to the cable insertion slot toward the first board 24 A as shown in FIG. 3 . Instead, fixed terminal portions 82 F of contact terminals 82 ai used in the cable connector shown in FIG. 11 are electrically connected from the back wall 30 BW to the first board 24 A through the slits 30 Si as shown in FIG. 14 .

Note that constituents in FIG. 11 to FIG. 15 which are the same as the constituents in the example shown in FIG. 4 will be designated by the same reference numerals and overlapping description thereof will be omitted.

As shown in FIG. 11 , the connection end portions of the flexible boards 10 are to be connected to the cable connector 30 , respectively. The cable connector 30 is fixed to the end portion of the mounting surface of the first board 24 A. The cable connector 30 includes, as its main elements: the pair of cable end portion accommodating portions into which the connection end portions on the one side of the flexible boards 10 are detachably inserted, respectively; the plurality of contact terminals 82 ai configured to electrically connect the connection end portions on the one side of the flexible boards 10 to the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and the pair of lever members 34 configured to press the connection end portions on the one side of the flexible boards 10 , which are inserted into the cable end portion accommodating portions, against contact portions of the contact terminals 82 ai and to hold the connection end portions thereon. Note that FIG. 11 to FIG. 13 illustrate only one of the cable end portion accommodating portions, and illustration of the other cable end portion accommodating portion is omitted therein.

As shown in an enlarged manner in FIG. 16 , the contact terminals 82 ai (i=1 to n, n is the positive integer) are made of a thin-plate metal material, for example, and include: contact portions 82 C to come into contact with the contact pads 22 ai (i=1 to n, n is the positive integer) of the connection end portion on the one side of the flexible board 10 ; the fixed terminal portions 82 F to be soldered and fixed to the end portions of the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and movable pieces 82 M to couple the contact portions 82 C to the fixed terminal portions 82 F.

Each contact portion 82 C is bent into an arc shape such that its tip end is directed to the surface of the first board 24 A. As shown in FIG. 13 and FIG. 14 , the fixed terminal portions 82 F are soldered and fixed to the conductive layers of the first board 24 A through the slits 30 Si. As shown in FIG. 15 , a pair of claw portions 82 mn to be locked with grooves 30 Gi in the partition walls 30 Pi are provided at two positions of each movable piece 82 M (see FIG. 16 ), and the movable piece 82 M extends toward the back wall 30 BW and is bent substantially into a U-shape at a position immediately above the fixed terminal portion 82 F as shown in FIG. 14 . Accordingly, when the pressing surface of the lever member 34 presses the connection end portion on the one side of the flexible board 10 against the contact portions 82 C of the plurality of contact terminals 82 ai and the contact end portion is held therein, a group of signals supplied to the contact terminals 82 ai through the conductive layers of the flexible board 10 are further supplied to the conductive layers of the first board 24 A along a direction indicated with an arrow C in FIG. 14 .

FIG. 17 shows external appearance of still another example of the cable connector to which the above-described cable connection structures according to the embodiments of the present invention are applied.

As shown in FIG. 17 , the connection end portions of the flexible boards 10 described above are to be connected to a cable connector 90 , respectively. The cable connector 90 is fixed to the end portion of the mounting surface of the first board 24 A described above, which is not illustrated. The cable connector 90 includes, as its main elements: a pair of cable end portion accommodating portions into which the connection end portions on the one side of the flexible boards 10 are detachably inserted, respectively; a plurality of contact terminals 92 ai configured to electrically connect the connection end portions on the one side of the flexible boards 10 to the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and a pair of lever members 94 configured to press the connection end portions on the one side of the flexible boards 10 , which are inserted into the cable end portion accommodating portions, against contact portions of the plurality of contact terminals 92 ai and to hold the connection end portions thereon. Note that FIG. 17 illustrates only one of the cable end portion accommodating portions, and illustration of the other cable end portion accommodating portion is omitted therein.

The one of the cable end portion accommodating portions is formed by being surrounded by side walls 90 RW and 90 LW, a back wall 90 BW, and a bottom wall, which collectively constitute a housing. The cable end portion accommodating portion has a cable insertion slot which is opened in the direction of extension of the above-described printed circuit board 24 . As shown in FIG. 18 , the cable end portion accommodating portion includes a plurality of slits 90 Si (i=1 to n, n is the positive integer) to which the contact terminals 92 ai are provided. The plurality of slits 90 Si are formed at given intervals along a Y coordinate axis in FIG. 17 . The Y coordinate axis is set parallel to a direction of arrangement of the contact terminals 92 ai.

The slits 90 Si penetrate the back wall 90 BW as shown in FIG. 18 . Every adjacent slits 90 Si are separated from each other by a corresponding one of partition walls 90 Pi (i=1 to n, n is the positive integer).

The lever members 94 serving as cable holding means are turnably provided above the cable end portion accommodating portions, respectively. Support shafts 94 S formed on two ends of each lever member 94 are inserted into a hole 90 a in the side wall 90 RW and a hole (not shown) in the side wall 90 LW. In the case where the flexible board 10 is attached to the cable connector 90 having the above-described configuration, the area of an opening of the cable insertion slot becomes largest when each lever member 94 is turned in one direction. Hence, the connection end portion on the one side of the flexible board 10 is inserted into the insertion slot. Thereafter, the lever member 94 is turned in another direction, which is an opposite direction to the one direction mentioned above, until tabs of the lever member 94 are inserted into grooves 90 G in the side walls 90 RW and 90 LW. Thus, a pressing surface of the lever member 94 presses the connection end portion on the one side of the flexible board 10 against contact portions 92 C of the plurality of contact terminals 92 ai , and the contact end portion is held in the corresponding cable end portion accommodating portion.

As shown in an enlarged manner in FIG. 18 , the contact terminals 92 ai (i=1 to n, n is the positive integer) are made of a thin-plate metal material, for example, and include: the contact portions 92 C to come into contact with the contact pads 22 ai of the connection end portion on the one side of the flexible board 10 ; fixed terminal portions 92 F to be soldered and fixed to the end portions of the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and movable pieces 92 M and fixed portions 92 N to couple the contact portions 92 C to the fixed terminal portions 92 F.

Each contact portion 92 C is bent into an arc shape such that its tip end is directed to the surface of the first board 24 A. The fixed terminal portions 92 F are soldered and fixed to the conductive layers of the first board 24 A through the slits 30 Si. A pair of claw portions to be locked with the grooves in the partition walls 30 Pi are provided at two positions of each fixed portion 92 N, and the fixed portion 92 N extends toward the back wall 90 BW. Accordingly, when the pressing surface of the lever member 94 presses the connection end portion on the one side of the flexible board 10 against the contact portions 92 C of the contact terminals 92 ai and the contact end portion is held thereon, a group of signals supplied to the contact terminals 92 ai through the conductive layers of the flexible board 10 reach the fixed terminal portions 92 F from the contact portions 92 C through the movable pieces 92 M as well as the fixed portions 92 N, and are further supplied to the conductive layers of the first board 24 A.

In addition, metallic contact pieces 96 T, 98 T, and 99 T of a conductive block unit come into contact with the fixed portions 92 N of particular contact terminals 92 ai among the contact terminals 92 ai , which are electrically connected to the ground line conductive layers (G) of the flexible board 10 . Contact terminals 92 ai to be electrically connected to two signal line conductive layers (S) are provided at a given interval between the particular contact terminals 92 ai that are electrically connected to the ground line conductive layers (G).

The conductive block unit is provided inside an opening of the back wall 90 BW, which is opened above the fixed portions 92 N of the plurality of contact terminals 92 ai.

As shown in an enlarged manner in FIG. 19 , the conductive block unit includes a block 96 , three blocks 98 , and a block 99 .

In FIG. 19 , the block 96 constituting a left end of the conductive block unit is made of a conductive resin material and formed into an angular shape having a corner at an upper left end. A lock portion extending to a position immediately above the fixed portion 92 N of the corresponding contact terminal 92 ai is formed at an end on one side of the block 96 . The lock portion includes lock projections 96 N 1 and 96 N 2 , which are located on a surface opposed to a peripheral edge of the above-described opening. In addition, a groove into which the contact piece 96 T is press-fitted is provided in a surface of the lock portion opposed to the fixed portion 92 N of the contact terminal 92 ai . A lower end of the contact piece 96 T is in contact with the fixed portion 92 N of the contact terminal 92 ai electrically connected to the corresponding ground line conductive layer (G).

The block 99 constituting a right end of the conductive block unit is made of a conductive resin material and formed into an angular shape having a corner at a lower right end. A lock portion extending to a position immediately above the fixed portion 92 N of the corresponding contact terminal 92 ai is formed at an end on one side of the block 99 . The lock portion includes lock projections, which are located at two positions adjacent to each other on a surface opposed to the peripheral edge of the above-described opening. These lock projections have similar structures as the lock projections 96 N 1 and 96 N 2 . In addition, a groove into which the contact piece 99 T is press-fitted is provided in a surface of the lock portion opposed to the fixed portion 92 N of the contact terminal 92 ai . A lower end of the contact piece 99 T is in contact with the fixed portion 92 N of the corresponding contact terminal 92 ai.

Each of the three blocks 98 having the same shape is made of a conductive resin material and formed into a crank shape having a first side and a second side. A lock portion extending to a position immediately above the fixed portion 92 N of the corresponding contact terminal 92 ai is formed at an end of the first side of each block 98 . The lock portion includes lock projections, which are located at two positions adjacent to each other on a surface opposed to the peripheral edge of the above-described opening. These lock projections have similar structures as the lock projections 96 N 1 and 96 N 2 . In addition, a groove into which the contact piece 98 T is press-fitted is provided in a surface of the lock portion opposed to the fixed portion 92 N of the contact terminal 92 ai . A lower end of the contact piece 98 T is in contact with the fixed portion 92 N of the corresponding contact terminal 92 ai . The first side of the block 98 is coupled to the second side of the adjacent block 98 with a metallic coupler. Thus, a given clearance CL is defined between every two adjacent blocks 98 . Moreover, the first side of the block 98 adjacent to the left-end block 96 is coupled to the other side of the block 96 with a metallic coupler. Thus, a given clearance CL is also defined between the left-end block 96 and the block 98 adjacent to the block 96 . Furthermore, the second side of the block 98 adjacent to the right-end block 99 is coupled to the other side of the block 99 with a metallic coupler. Thus, a given clearance CL is also defined between the right-end block 99 and the block 98 adjacent to the block 99 .

Accordingly, the block 96 , the blocks 98 , and the block 99 collectively form the conductive block unit by being linearly arranged and coupled to one another.

Note that the block 96 , the blocks 98 , and the block are not limited to the above-described example. Specifically, the adjacent blocks do not have to be coupled to one another with the metallic couplers.

The inventor of the present application has confirmed that, regarding transmission characteristics of the group of signals obtained through the cable connector 90 , a peak of the insertion loss and a peak of the crosstalk are attenuated in a predetermined frequency range since the contact terminals 92 ai electrically connected to the ground line conductive layers (G) are set to the same electric potential as each other according to the above-described configuration.

FIG. 20 shows the cable connector 90 including a modified example of the above-described conductive block unit. The cable connector 90 shown in FIG. 17 includes the conductive block unit formed from the plurality of blocks. Instead, in the example shown in FIG. 20 , the cable connector 90 includes a single conductive block 86 that is integrally formed. Note that constituents in FIG. 20 which are the same as the constituents in the example shown in FIG. 17 will be designated by the same reference numerals and overlapping description thereof will be omitted.

The conductive block 86 made of a conductive resin material extends in the Y coordinate axis, and is provided inside the opening of the back wall 90 BW which is opened above the fixed portions 92 N of the plurality of contact terminals 92 ai.

As shown in FIG. 21 , the conductive block 86 is provided with a lock portion extending to a position immediately above the fixed portion 92 N of the corresponding contact terminal 92 ai . The lock portion includes lock projections 86 N 1 and 86 N 2 , which are located on a surface opposed to the peripheral edge of the above-described opening. In addition, as shown in FIG. 20 , projections 86 N 3 to come into contact with the fixed portions 92 N of the particular contact terminals 92 ai electrically connected to the ground line conductive layers (G) are formed at five positions at given intervals, for example, on a surface of the lock portion opposed to the fixed portions 92 N of the contact terminals 92 ai . Each projection 86 N 3 projects by a predetermined height toward the fixed portion 92 N of the corresponding contact terminal 92 ai located immediately therebelow.

FIG. 22 shows external appearance of yet another example of the cable connector to which the above-described cable connection structures according to the embodiments of the present invention are applied.

The cable connector shown in FIG. 22 includes the contact terminals 92 ai in a fewer number than that of the contact terminals 92 ai provided to the cable connector shown in FIG. 20 , and also includes a conductive block 88 in a smaller size than the size of the conductive block 86 . Note that constituents in FIG. 22 which are the same as the constituents in the example shown in FIG. 20 will be designated by the same reference numerals and overlapping description thereof will be omitted.

The connection end portions of the flexible boards 10 described above are to be connected to a cable connector 100 , respectively. The cable connector 100 is fixed to the end portion of the mounting surface of the first board 24 A described above, which is not illustrated. The cable connector 100 includes, as its main elements: the pair of cable end portion accommodating portions into which the connection end portions on the one side of the flexible boards 10 are detachably inserted, respectively; the plurality of contact terminals 92 ai configured to electrically connect the connection end portions on the one side of the flexible boards 10 to the plurality of signal layers 24 S and the plurality of ground layers 24 G of the first board 24 A; and a pair of lever members 104 configured to press the connection end portions on the one side of the flexible boards 10 , which are inserted into the cable end portion accommodating portions, against the contact portions of the plurality of contact terminals 92 ai and to hold the connection end portions thereon. Note that FIG. 22 illustrates only one of the cable end portion accommodating portions, and illustration of the other cable end portion accommodating portion is omitted therein.

The one of the cable end portion accommodating portions is formed by being surrounded by side walls 100 RW and 100 LW, a back wall 100 BW, and a bottom wall, which collectively constitute a housing. The cable end portion accommodating portion has a cable insertion slot which is opened in the direction of extension of the above-described printed circuit board 24 . Each cable end portion accommodating portion includes a plurality of slits to which the contact terminals 92 ai are provided. The plurality of slits are formed at given intervals along a Y coordinate axis in FIG. 22 . The Y coordinate axis is set parallel to the direction of arrangement of the contact terminals 92 ai.

The slits penetrate the back wall 100 BW. Every adjacent slits are separated from each other by a partition wall.

The lever members 104 serving as cable holding means are turnably provided above the cable end portion accommodating portions, respectively. Support shafts 104 S formed on two ends of each lever member 104 are inserted into a hole 100 a in the side wall 100 RW and a hole (not shown) in the side wall 100 LW. In the case where the flexible board 10 is attached to the cable connector 100 having the above-described configuration, the area of an opening of the cable insertion slot becomes largest when each lever member 104 is turned in one direction. Hence, the connection end portion on the one side of the flexible board 10 is inserted into the insertion slot. Thereafter, the lever member 104 is turned in another direction, which is an opposite direction to the one direction mentioned above, until tabs of the lever member 104 are inserted into grooves 100 G in the side walls 100 RW and 100 LW. Thus, a pressing surface of the lever member 104 presses the connection end portion on the one side of the flexible board 10 against the contact portions 92 C of the plurality of contact terminals 92 ai , and the contact end portion is held in the corresponding cable end portion accommodating portion.

In addition, projections 88 N 3 of the conductive block 88 come into contact with the fixed portions 92 N of particular contact terminals 92 ai among the contact terminals 92 ai , which are electrically connected to the ground line conductive layers (G) of the flexible board 10 . Contact terminals 92 ai to be electrically connected to two signal line conductive layers (S) are provided at a given interval between the particular contact terminals 92 ai that are electrically connected to the ground line conductive layers (G).

The conductive block 88 made of a conductive resin material extends in the Y coordinate axis, and is provided inside an opening of the back wall 100 BW which is opened above the fixed portions 92 N of the plurality of contact terminals 92 ai.

The conductive block 88 is provided with a lock portion extending to a position immediately above the fixed portion 92 N of the corresponding contact terminal 92 ai . The lock portion includes lock projections, which are located at two positions on a surface opposed to a peripheral edge of the above-described opening. In addition, projections 88 N 3 to come into contact with the fixed portions 92 N of the particular contact terminals 92 ai electrically connected to the ground line conductive layers (G) are formed at two positions at a given interval, for example, on a surface of the lock portion opposed to the fixed portions 92 N of the contact terminals 92 ai . Each projection 88 N 3 projects by a predetermined height toward the fixed portion 92 N of the corresponding contact terminal 92 ai located immediately therebelow.

In this example as well, the inventor of the present application has confirmed that, regarding transmission characteristics of a group of signals obtained through the cable connector 100 , a peak of an insertion loss and a peak of crosstalk are attenuated in a predetermined frequency range since the contact terminals 92 ai electrically connected to the ground line conductive layers (G) are set to the same electric potential as each other according to the above-described configuration.

Note that the examples of the cable connection structures according to the present invention are not limited to the application to the above-described transceiver module but are, of course, also applicable to cable connecting parts of other devices, for instance.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.