# Patent

## Title
Board-connecting electric connector

## Abstract

A good mating state can be obtained while reducing interference of transmission signals by a simple configuration. A contact portion is provided at a single location on each of mating recessed portions of signal contact members arranged in a multipolar shape, contact portions are provided at a plurality of locations for a mating recessed portion of an integrated power-source contact member, and signal transmission is carried out through the single-location contact portion provided at the single location for each of the mating recessed portions of the signal contact members. As a result, particularly, interference in high-frequency transmission is reduced to obtain good transmission characteristics, while sufficient mating retention force is configured to be obtained by causing the contact portions at the plurality of locations provided on the mating recessed portion of the power-source contact member to be in a state in which the contact portions are in contact with contact portions of a mating counterpart by the plurality of locations.

## Background
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to board-connecting electric connectors mutually connected in a state in which they are mounted on wiring boards.
Generally, in various electric devices, board-connecting electric connector devices referred to as stacking connectors, etc. are widely used. In the board-connecting electric connector device, for example, above a first electric connector (receptacle connector) coupled to a first wiring board, a second electric connector (plug connector) coupled to a second wiring board is disposed so as to be opposed thereto, the second electric connector in the upper side is pushed in so as to be lowered toward the first electric connector in the lower side from such a vertically opposed state, and both of the electric connectors are brought into a mutually mated state as a result, thereby electrically connecting the first and second wiring boards to each other.
In order to improve the electric connection characteristics of a board-connecting electric connector device like this, the state in which both of the electric connectors are mated with each other has to be maintained well. Conventionally, in order to obtain good and sufficient mating force, for example as disclosed in below described Japanese Patent Application Laid-Open No. 2014-170726, the cases in which the number of the contact portions provided on contact members or other mating members is increased to obtain a multipoint contact state are increasing.
However, under the circumstances of recent years in which the frequencies of transmission signals are being increased, it is conceivable that the signals transmitted through a plurality of contact portions mutually cause interference, etc. in contact members and affect transmission characteristics.
Herein, the inventor of the present application discloses below Patent Document as prior techniques of the present invention.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2014-170726
SUMMARY OF THE INVENTION
Therefore, it is an object of the present invention to provide a board-connecting electric connector that enables to reduce the interference of transmission signals and, at the same time, to obtain a good mating state by a simple configuration.
The invention according to claim 1 in order to achieve the above described object employs a configuration of an electric connector having a plurality of signal contact members arranged in a multipolar shape and a power-source contact member or a ground contact member attached to an insulating housing, the electric connector configured so that contact portions provided on the signal contact members and the power-source contact member or the ground contact member are electrically connected to contact portions provided on a mating counterpart; the electric connector having: the signal contact members and the power-source contact member or the ground contact member each provided with a mating recessed portion receiving the mating counterpart and provided with a solder connection portion extending from the mating recessed portion in a direction orthogonal to a direction of arrangement of the multipolar shape; the contact portion of the signal contact member provided at a single location for each mating recessed portion of each of the signal contact members; and the contact portions of the power-source contact member or the ground contact member provided at a plurality of locations for the mating recessed portion of the power-source contact member or the ground contact member integrated therewith.
According to the present invention provided with such a configuration, signals are transmitted through the contact portion provided at the single location for each of the mating recessed portions of the signal contact members. Therefore, particularly, the interference in high-frequency transmission is reduced, and good transmission characteristics are obtained. On the other hand, since the contact portions at the plurality of locations provided on the mating recessed portion of the power-source contact member or the ground contact member is brought into the state in which they contact the contact portions of the mating counterpart, sufficient mating retention force is obtained.
Moreover, in the present invention, the power-source contact member or the ground contact member can be disposed at an outer position in the direction of arrangement of the multipolar shape of the plurality of signal contact members.
Moreover, it is desired that the signal contact member of the present invention be configured so as to sandwich the mating counterpart by the contact portion and part of the insulating housing when mated with the mating counterpart.
According to the present invention provided with such a configuration, the contact portion of the signal contact member is structured to be pressed against the mating counterpart by the insulating housing sandwiching the signal contact member. Therefore, the electric connectivity of the contact portion is enhanced, and impedance matching of the signal transmission utilizing the dielectric property of the insulating housing can be expected.
Moreover, in the present invention, it is desired that the signal contact member and the power-source contact member or the ground contact member be formed by band-plate-shaped members having predetermined width sizes in the direction of arrangement of the multipolar shape; and the width size of the band-plate-shaped member constituting the power-source contact member or the ground contact member be formed to be larger than the width size of the band-plate-shaped member constituting the signal contact member.
According to the present invention provided with such a configuration, the mating retention force by the power-source contact member or the ground contact member is further enhanced.
Moreover, in the present invention, the power-source contact member or the ground contact member can have the contact portions at two locations; and one of the contact portions at the two locations can be formed into a lock portion that becomes a mechanically latched state when mated with the mating counterpart.
As described above, in the board-connecting electric connector according to the present invention, on the plurality of signal contact members arranged in a multipolar shape and the power-source contact member or the ground contact member, the contact portion is provided at the single location for each of the mating recessed portions of the signal contact members, the contact portions are provided at the plurality of locations for the mating recessed portion of the power-source contact member or the ground contact member integrated therewith, and signals are transmitted through the single-location contact portion provided at the single location for each of the mating recessed portions of the signal contact members. As a result, particularly, interference in high-frequency transmission is reduced, and good transmission characteristics are obtained; on the other hand, sufficient mating retention force is configured to be obtained by causing the contact portions at the plurality of locations provided on the mating recessed portion of the power-source contact member or the ground contact member to be in a state in which they contact the contact portions of the mating counterpart by the plurality of locations. Therefore, by a simple configuration, a good mating state can be obtained while reducing the interference of transmission signals, and the reliability of the board-connecting electric connector can be significantly enhanced at low cost.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an explanatory external perspective view showing, from an upper side, a first electric connector (receptacle connector) according to an embodiment of the present invention;
FIG. 2 is an explanatory external perspective view showing, from a lower side, the first electric connector (receptacle connector) according to the embodiment of the present invention shown in FIG. 1;
FIG. 3 is an explanatory plan view showing the first electric connector (receptacle connector) according to the embodiment of the present invention shown in FIG. 1 and FIG. 2;
FIG. 4 is an explanatory front view showing the first electric connector (receptacle connector) according to the embodiment of the present invention shown in FIG. 1 to FIG. 3;
FIG. 5 is an explanatory lateral view showing the first electric connector (receptacle connector) according to the embodiment of the present invention shown in FIG. 1 to FIG. 4;
FIG. 6 is an enlarged explanatory transverse-sectional view taken along a line VI-VI in FIG. 3;
FIG. 7 is an enlarged explanatory transverse-sectional view taken along a line VII-VII in FIG. 3;
FIG. 8 is an explanatory transverse-sectional view taken along a line VIII-VIII in FIG. 3;
FIG. 9 is an explanatory external perspective view showing the first electric connector (receptacle connector) according to the embodiment of the present invention shown in FIG. 1 to FIG. 8 in an exploded manner;
FIG. 10 is an explanatory external perspective view showing, from the upper side, a second electric connector (plug connector) according to the embodiment of the present invention to be mated with the first electric connector (receptacle connector) shown in FIG. 1 to FIG. 9;
FIG. 11 is an explanatory external perspective view showing, from the lower side, the second electric connector (plug connector) according to the embodiment of the present invention shown in FIG. 10;
FIG. 12 is an explanatory plan view showing the second electric connector (plug connector) according to the embodiment of the present invention shown in FIG. 10 and FIG. 11;
FIG. 13 is an explanatory front view showing the second electric connector (plug connector) according to the embodiment of the present invention shown in FIG. 10 to FIG. 12;
FIG. 14 is an explanatory lateral view showing the second electric connector (plug connector) according to the embodiment of the present invention shown in FIG. 10 to FIG. 13;
FIG. 15 is an enlarged explanatory transverse-sectional view taken along a line XV-XV in FIG. 12;
FIG. 16 is an enlarged explanatory transverse-sectional view taken along a line XVI-XVI in FIG. 12;
FIG. 17 is an explanatory transverse-sectional view taken along a line XVII-XVII in FIG. 12;
FIG. 18 is an explanatory external perspective view showing the second electric connector (plug connector) according to the embodiment of the present invention shown in FIG. 10 to FIG. 17 in an exploded manner;
FIG. 19 is an explanatory external perspective view showing, from the upper side a state in which the first and second electric connectors according to the embodiment of the present invention are mated with each other;
FIG. 20 is an explanatory external perspective view showing, from the lower side, the mutually mated state of the first and second electric connectors shown in FIG. 19;
FIG. 21 is an explanatory plan view showing the mutually mated state of the first and second electric connectors shown in FIG. 19 and FIG. 20;
FIG. 22 is an explanatory front view showing the mutually mated state of the first and second electric connectors shown in FIG. 19 and FIG. 20;
FIG. 23 is an explanatory lateral view showing the mutually mated state of the first and second electric connectors shown in FIG. 19 and FIG. 20;
FIG. 24 is an enlarged explanatory transverse-sectional view shown together with wiring boards along a line XXIV-XXIV in FIG. 21;
FIG. 25 is an enlarged explanatory sectional view shown together with the wiring boards along a line XXV-XXV in FIG. 21;
FIG. 26 is an explanatory transverse-sectional view shown together with the wiring boards along a line XXVI-XXVI in FIG. 21;
FIG. 27 is an explanatory external perspective view showing a positioned state for mutually mating the first and second electric connectors according to the embodiment of the present invention;
FIG. 28 is an explanatory front view showing the positioned state for mutually mating the first and second electric connectors according to the embodiment of the present invention;
FIG. 29 is an explanatory lateral view showing the positioned state for mutually mating the first and second electric connectors according to the embodiment of the present invention;
FIG. 30 is an explanatory external perspective view showing a structure example of a printed wiring board on which the first electric connector (receptacle connector) is to be mounted; and
FIG. 31 is an explanatory external perspective view showing a structure example of a printed wiring board on which the second electric connector (plug connector) is to be mounted.



DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, an embodiment to which the present invention is applied will be described in detail based on drawings.
[About Overall Structure of Electric Connector Device]
A board-connecting electric connector device according to the embodiment of the present invention shown in the drawings is used for, for example, electrically connecting wiring boards, which are disposed in an electric device of various types such as a mobile phone, a smartphone, or a tablet-type computer, to each other and is composed of a receptacle connector 10 serving as a first electric connector shown in FIG. 1 to FIG. 9 and a plug connector 20 serving as a second electric connector shown in FIG. 10 to FIG. 18. The receptacle connector (first electric connector) 10 is mounted on a first wiring board P1 shown in, for example, FIG. 30; the plug connector (second electric connector) 20 is mounted on a second wiring board P2 shown in, for example FIG. 31; and, when both of the electric connectors 10 and 20, which are in such a mounted state, are disposed so as to be opposed to each other and are subjected to a mating operation, the above described first and second wiring boards P1 and P2 are electrically connected to each other.
In the below description, the mating direction of the receptacle connector (first electric connector) 10 and the plug connector (second electric connector) 20 is assumed to be “up-down direction”. The plug connector 20 is disposed at a position above the receptacle connector 10, which is disposed at a lower position in the up-down direction; in such an opposed state in the up-down direction, a positioning operation is carried out in a state in which both of the electric connectors 10 and 20 contact each other as shown in FIG. 27 to FIG. 29; when they are positioned at mating positions, the plug connector 20 is pushed in toward a downward direction; and, as a result, both of the electric connectors 10 and 20 are caused to be in a mutually mated state as shown in FIG. 19 to FIG. 26.
Also, when the plug connector (second electric connector) 20 is pulled up toward the upper side with appropriate force from the above described mating state, the plug connector 20 is removed from the lower-side receptacle connector (first electric connector) 10 toward the upper side.
The operations of mating/removing the plug connector (second electric connector) 20 with/from the receptacle connector (first electric connector) 10 in this manner are not limited to be carried out by the hand(s) of an operator, but may be automatically carried out by a predetermined jig or machine.
Note that, when the mating/removal of both of the electric connectors 10 and 20 with/from each other is to be carried out, the plug connector (second electric connector) 20 disposed in the upper side is in a vertically inverted state and is disposed to be opposed to the receptacle connector (first electric connector) 10 disposed in the lower side. However, in the description of the single plug connector 20, the description will be given in the state before inversion, in other words, in the state in which the plug connector 20 is mounted from the upper side onto the second wiring board P2 disposed in the lower side.
The receptacle connector (first electric connector) 10 and the plug connector (second electric connector) 20, which constitute the board-connecting electric connector device like this, respectively have insulating housings 11 and 21 extending in long and thin shapes. The insulating housings 11 and 21 have undergone, for example, mold forming by using a resin material such as plastic, and many signal contact members 13 and 23 are arranged along the longitudinal direction of the insulating housings 11 and 21 so as to form multipolar shapes at predetermined pitches. The longitudinal direction of the insulating housings 11 and 21, which is the arrangement direction of the signal contact members 13 and 23, will be hereinafter referred to as “connector longitudinal direction”, and the short-side direction orthogonal to the “connector longitudinal direction” and the “up-down direction” will be referred to as “connector width direction”.
Particularly as shown in FIG. 9 and FIG. 18, each of these insulating housings 11 and 21 has base end portions ha and ha or 21a and 21a at both end parts of the insulating housing 11 or 21 in the longitudinal direction (connector longitudinal direction). A central projecting portion 11b is provided so as to integrally bridge the connector-width-direction central parts of the base end portions ha and ha to each other in the connector longitudinal direction, and a central recessed portion 21b is provided so as to integrally bridge the connector-width-direction central parts of the base end portions 21a and 21a to each other in the connector longitudinal direction. In this manner, the base end portions 11a, 11a and 21a, 21a of the insulating housings 11 and 21 are in the disposition relations in which the base end portions are opposed to each other in the connector longitudinal direction via the central projecting portion 11b and the central recessed portion 21b, and electrically-conductive shells 12 and 22 are attached so as to bridge the base end portions 11a and 11a to each other and the base end portions 21a and 21a to each other.
The electrically-conductive shells 12 and 22 constitute shield wall portions for later-described signal contact members 13 and 14, are formed by bent structures of electrically-conductive members formed of thin-plate-shaped metal members or the like, and are attached so as to surround the outer peripheral parts of the above described insulating housings 11 and 21 and so as to sandwich them from both sides in the connector longitudinal direction and the connector width direction. Herein, the electrically-conductive shells (shield wall portions) 12 attached to the receptacle connector (first electric connector) 10 side are fixed by press-fitting from the upper side with respect to the insulating housing 11; and, on the other hand, the electrically-conductive shells (shield wall portions) 22 attached to the plug connector (second electric connector) 20 side are fixed by insert molding with respect to the insulating housing 21.
Also, at the central projecting portion 11b and the central recessed portion 21b of the above described insulating housings 11 and 21, contact attachment grooves 11c and 21c, which form recessed groove shapes, are provided in a recessed manner so as to be juxtaposed at constant intervals along the connector longitudinal direction, and the signal contact members 13 and 23 and power-source contact members 14 and 24 are attached to the contact attachment grooves 11c and 21c by press-fitting and insert molding, respectively. The signal contact members 13 and 23 among them are arranged at the constant intervals so as to form multipolar shapes along the connector longitudinal direction, and the power-source contact members 14 and 24 are disposed at both-side outer positions of the signal contact members 13 and 23 in the multipolar-shape arrangement direction (connector longitudinal direction).
The overall configuration of the receptacle connector (first electric connector) 10 and the plug connector (second electric connector) 20 is roughly as described above, and the detailed configuration and disposition relation of each part will be described below.
First, each of the signal contact members 13, which are attached to the insulating housing 11 of the receptacle connector (first electric connector) 10 by press-fitting, and the signal contact members 23, which are attached to the insulating housing 21 of the plug connector (second electric connector) 20 by insert molding, has a disposition relation in which two electrode rows extending approximately in parallel along the connector longitudinal direction are formed for the electric connector 10 or 20 thereof. The signal contact members 13 and 13 or the signal contact members 23 and 23 constituting the two electrode rows have a disposition relation so as to be symmetrically opposed to each other in the connector width direction. The below description describes the signal contact members 13 and 13 and the signal contact members 23 and 23, which have such symmetrical disposition relations, as the same without distinguishing them.
[About Contact Members of Receptacle Connector]
More specifically, first, particularly as shown in FIG. 7, at the central projecting portion 11b of the insulating housing 11 to which the signal contact members 13 of the receptacle connector (first electric connector) 10 side are attached, a partition plate 11d projecting from a bottom surface plate toward the upper side is provided in the part between the above described two electrode rows, in other words, at a connector-width-direction central part so as to form a band plate shape and extend along the connector longitudinal direction. This partition plate 11d constitutes the groove bottom parts of the above described contact attachment grooves 11c, and, in the spatial parts between the partition plate 11d and the longitudinal lateral wall portions 11e and 11e, which are provided to stand in the connector-width-direction both sides of the partition plate 11d, the pair of the signal contact members 13 and 13 constituting the electrode rows in both sides is disposed in a positional relation in which they are opposed to each other so as to form symmetrical shapes in the connector width direction.
Each of these signal contact members 13 is formed by a band-plate-shaped member made of metal which is bent so as to extend to form a curved shape from the connector central side toward the outer side in the connector width direction, and the signal contact member 13 is attached to the above described contact attachment groove 11c by press-fitting from the lower side. The signal contact member 13 is formed so that a mating recessed portion 13a, which is bent and formed so as to extend in an approximately U-shape, is hollowed so as to form a recessed shape at a connector central-side part close to the above described partition plate 11d; and part of the signal contact member 23 of the plug connector (second electric connector) 20, which is a mating counterpart, is configured to be inserted in and received by the inner space of the mating recessed portion 13a from the upper side.
More specifically, the mating recessed portion 13a of the signal contact member 13 extending to form the approximately U-shape in the above described manner has an outer rising side portion 13c and an inner rising side portion 13d, which rise toward the upper side from both sides of a bottom side portion 13b extending in the connector width direction. Among the inner/outer both-side rising side portions 13c and 13d, the outer rising side portion 13c, which is disposed in the outer side in the connector width direction, is caused to be in a fixed state by press-fitting from the lower side into the contact attachment groove 11c, which is provided in a recessed manner in the above described longitudinal lateral wall portion 11e. The above described bottom side portion 13b is extending in a cantilever shape from the outer rising side portion 13c, which is in the fixed state, toward the connector central side (inner side), and the inner rising side portion 13d is also extending in a cantilever shape via the bottom side portion 13b. The inner rising side portion 13d is disposed so as to be close to the partition plate 11d in the connector central side and is configured to be elastically displaceable in the connector width direction with respect to the outer rising side portion 13c, which is in the fixed state as described above.
The upper end part of the inner rising side portion 13d, which is disposed in the connector central side, has undergone bend forming so as to extend to form a curved shape toward the inner space of the above described mating recessed portion 13a, and a projection-shaped contact portion 13e is formed at a part of the curved-shape bent part that is bulging to the inner space of the mating recessed portion 13a. The projection-shaped contact portion 13e is configured to have a relation in which, when part of the signal contact member 23 of the plug connector (second electric connector) 20 is inserted in the inner space of the mating recessed portion 13a in the above described manner, the projection-shaped contact portion 13e contacts and is electrically connected to the part of the signal contact member 23. This point will be described in detail later.
On the other hand, the outer rising side portion 13c, which is disposed in the connector outer side, is caused to be in an insulated state in which the outer rising side portion 13c is inserted and buried in the longitudinal lateral wall portion 11e in the above described manner. In other words, as shown in FIG. 25, without electrically contacting the signal contact member 23 of the plug connector (second electric connector) 20, which is the mating counterpart, the inner surface of the longitudinal lateral wall portion 11e is configured to contact and be pressed against part of the signal contact member 23, which is inserted in the inner space of the mating recessed portion 13a. 
In this manner, the signal contact members 13 of the receptacle connector (first electric connector) 10 are configured so that the projection-shaped contact portion 13e at each location is provided for each of the mating recessed portions 13a of the signal contact members 13, and signal transmission with respect to the signal contact member 23 of the plug connector (second electric connector) 20 is configured to be carried out via the projection-shaped contact portion 13e, which is provided at each location for each of the signal contact members 13.
Also, the outer rising side portion 13c of the signal contact member 13 like this is raised from the above described bottom side portion 13b to the upper-surface position of the receptacle connector (first electric connector) 10, bulges toward the connector outer side, is then bent in a reversed U-shape so as to be inverted toward the lower side, and, at the lower-surface position of the receptacle connector 10, is bent again approximately at right angle toward the connector outer side and formed into a board-connecting leg portion (contact connecting portion) 13f. The board-connecting leg portion 13f is extending approximately horizontally toward the outer side in the connector width direction and is configured to be solder-joined with a signal-transmitting electrically-conductive path (signal pad) P1a on the first wiring board P1 particularly as shown in FIG. 30 when the receptacle connector 10 is mounted on the first wiring board P1. The solder joining of the board-connecting leg portions 13f is carried out collectively for all the board-connecting leg portions 13f by using a solder material having a long shape.
Moreover, at each of the both-side outer positions in the arrangement direction of the multipolar shape of the above described plurality of signal contact members 13 and 13, and so on, the pair of power-source contact members 14 and 14 is attached to the contact attachment grooves 11c of the central projecting portion 11b. The power-source contact members 14 and 14 basically have similar configurations as the above described signal contact members 13 except the structures of the contact portions and have a disposition relation in which the power-source contact members 14 and 14 are opposed to each other so as to form symmetrical shapes in the connector width direction in the both sides sandwiching the partition plate 11d. 
Each of these power-source contact members 14 is also formed by a band-plate-shaped member made of metal which is bent so as to form a curved shape and extend from the connector-width-direction connector central side toward the outer side, and, particularly as shown in FIG. 9, a plate-width size W1 of the power-source contact member (or ground contact member) 14 is set to have a size that is several times a plate-width size W2 of the above described signal contact member 13 or more than that (W1>W2).
Also in the power-source contact member 14 like this, at a connector central-side part close to the above described partition plate 11d as shown in FIG. 6, a mating recessed portion 14a hollowed to form a recessed shape is bent and formed so as to extend in an approximately U-shape, and part of the power-source contact member 24 of the plug connector (second electric connector) 20, which is the mating counterpart, is configured to be received so as to be inserted from the upper side into the inner space of the mating recessed portion 14a. 
More specifically, the mating recessed portion 14a of the power-source contact member 14 extending to form the approximately U-shape in the above described manner has an outer rising side portion 14c and an inner rising side portion 14d, which rise toward the upper side from both sides of a bottom side portion 14b extending in the connector width direction. Among the inner/outer both-side rising side portions 14c and 14d, the outer rising side portion 14c, which is disposed in the outer side in the connector width direction, is caused to be in a fixed state by press-fitting from the lower side into the contact attachment groove 11c, which is provided in a recessed manner in the above described longitudinal lateral wall portion 11e. Also, the inner rising side portion 14d is extending in a cantilever shape from the outer rising side portion 14c, which is in such a fixed state, via the above described bottom side portion 14b. The inner rising side portion 14d is disposed so as to be close to the partition plate 11d in the connector central side and is configured to be elastically displaceable in the connector width direction with respect to the outer rising side portion 14c, which is in the fixed state as described above.
The upper end part of the inner rising side portion 14d, which is disposed in the connector central side, has undergone bend forming so as to extend to form a curved shape toward the inner space of the above described mating recessed portion 14a, and a projection-shaped contact portion 14e is formed at a part of the curved-shape bent part that is bulging to the inner space of the mating recessed portion 14a. The projection-shaped contact portion 14e is configured to have a relation in which, when part of the power-source contact member 24 of the plug connector (second electric connector) 20, which is the mating counterpart, is inserted in the inner space of the mating recessed portion 14a in the above described manner, the projection-shaped contact portion 14e contacts and is electrically connected to the part of the power-source contact member 24. This point will be described in detail later.
On the other hand, a recess-shaped contact portion 14f is formed at an intermediate position of the part in which the outer rising side portion 14c, which is disposed in the connector outer side, is extending in the up-down direction. The recess-shaped contact portion 14f is configured to contact and be electrically connected to part of the power-source contact member 24 when the part of the power-source contact member 24 of the plug connector (second electric connector) 20, which is the mating counterpart, is inserted in the inner space of the mating recessed portion 14a in the above described manner. This point will be also described later in detail.
In this manner, the power-source contact member 14 of the receptacle connector (first electric connector) 10 is configured to be provided with the contact portions at two locations consisting of the projection-shaped contact portion 14e and the recess-shaped contact portion 14f for the mating recessed portion 14a of each of the power-source contact members 14, and supply of power-source currents is configured to be carried out with respect to the power-source contact member 24 of the plug connector (second electric connector) 20, which is the mating counterpart, via the contact portions 14e and 14f at the two locations.
Also, the outer rising side portion 14c of the above described power-source contact member 14 is raised to the upper-surface position of the receptacle connector (first electric connector) 10, is then bent so as to be inverted toward the lower side while bulging toward the connector outer side, and, at the lower-surface position of the receptacle connector 10, is bent approximately at right angle toward the connector outer side and formed into a board-connecting leg portion (contact connecting portion) 14g. The board-connecting leg portion 14g is extending approximately horizontally toward the outer side in the connector width direction and is configured to be solder-joined with a power-supplying electrically-conductive path (signal pad) P1b on the first wiring board P1 in a case of mounting of the receptacle connector 10. The solder-joining of the board-connecting leg portions 14g is carried out collectively for all the board-connecting leg portions 14g by using a solder material having a long shape.
[About Contact Members of Plug Connector]
Next, the central recessed portion 21b of the insulating housing 21 of the plug connector (second electric connector) 20 has a pair of longitudinal lateral wall portions 21d and 21d extending approximately in parallel along the connector longitudinal direction (multipolar-shape arrangement direction), and the signal contact members 23 and the power-source contact members 24 are attached to the contact attachment grooves 21c having recessed groove shapes, which are arranged at constant intervals along the connector longitudinal direction of the longitudinal lateral wall portions 21d, by insert molding so as to constitute two electrode rows. The signal contact members 23 and the power-source contact members 24 constituting the two electrode rows are in a disposition relation in which they are symmetrically opposed to each other in the connector width direction.
More specifically, at the central recessed portion 21b of the insulating housing 21 to which the signal contact members 23 and the power-source contact members 24 are attached, particularly as shown in FIG. 15 and FIG. 16, the part between the above described two electrode rows, in other words, the part between the longitudinal lateral wall portions 21d and 21d in both sides is formed into a recess-shaped space extending in the connector longitudinal direction, and the signal contact members 23 and the power-source contact members 24 are attached so as to be wound around the outer peripheral side of the longitudinal lateral wall portions 21d. Each pair of the signal contact members 23 and 23 and each pair of the power-source contact members 24 and 24 constituting the electrode rows of the both sides are disposed in a positional relation in which they are opposed to each other so as to form symmetrical shapes in the connector width direction.
Each of the signal contact members 23 and the power-source contact members 24 is formed by a band-plate-shaped member made of metal which is bent so as to form a curved shape of a reversed U-shape and extend so as to cover upper edge portions of the above described longitudinal lateral wall portions 21d, and, particularly as shown in FIG. 18, the plate-width size W3 of the power-source contact member 24 is set to have a size that is several times the plate-width size W4 of the signal contact member 23 or larger than that (W3>W4).
In this manner, in the present embodiment, the width size W1 or W3 of the band-plate-shaped members constituting the power-source contact member 14 or 24 is formed to be larger than the width size W2 or W4 of the band-plate-shaped member constituting the signal contact member 13 or (W1, W3>W2, W4). Therefore, the mating retention force by the power-source contact member 14 or 24 is configured to be higher compared with the signal contact member 13 or 23.
Particularly, in the present embodiment, since the power-source contact members 14 and 24 having the large mating retention force compared with the signal contact members 13 and 23 are configured to be disposed at four corners in a planar view of the electric connector device, the power-source contact members 14 and 24 have functions as simple lock mechanisms about mating of both of the electric connectors 10 and 20.
In each of the signal contact members 23 and the power-source contact members 24, the part that forms a reversed U-shape and projects to the upper side is formed into a mating projection portion 23a or a mating projection portion 24a. The mating projection portions 23a and the mating projection portions 24a are configured to be inserted from the upper side into the mating recessed portions 13a and the mating recessed portions 14a, which are provided in the signal contact members 13 and the power-source contact members 14 of the receptacle connector (first electric connector) 10, which is a mating counterpart, and to be received when the signal contact members 13 and the power-source contact members 14 are elastically displaced.
Herein, the mating projection portions 23a and the mating projection portions 24a, which form the reversed U-shapes in the above described signal contact members 23 and the power-source contact members 24 have connector-central-side inner wall surfaces and connector-outer-side outer wall surfaces extending approximately in parallel in the up-down direction; and, among both of the connector inner/outer wall surfaces, on each of the inner wall surfaces of the mating projection portions 23a, a recess-shaped contact portion 23b is formed. The recess-shaped contact portions 23b of the plug connector 20 side are configured to elastically contact and be electrically connected to the projection-shaped contact portions 13e of the receptacle connector 10 side when both of the electric connectors 10 and 20 are mated with each other, wherein the mating projection portions 23a and 24a of the signal contact members 23 and the power-source contact members 24 provided in the plug connector (second electric connector) 20 are inserted in the inner spaces of the mating recessed portions 13a and 14a of the signal contact members 13 and the power-source contact members 14 provided in the above described receptacle connector (first electric connector) 10.
On the other hand, the outer wall surface of the mating projection portion 23a provided in the signal contact member 23 is extending to form a flat surface shape. As shown in FIG. 25, the outer wall surface of the mating projection portion 23a, which is provided so as to form the flat surface shape in the plug connector 20 side, is configured to be brought into a state in which it contacts and is pressed against the inner wall surface of the longitudinal lateral wall portion 11e, which is provided in the insulating housing 11 in the above described receptacle connector (first electric connector) 10 side, from the connector central side, thereby achieving an insulated state in which electrical connection is not established when both of the electric connectors 10 and 20 are mated with each other, wherein the mating projection portion 23a of the signal contact member 23 provided in the plug connector (second electric connector) 20 is inserted in the inner space of the mating recessed portion 13a of the signal contact member 13, which is provided in the above described receptacle connector (first electric connector) 10.
In this manner, in the present embodiment, when both of the electric connectors 10 and 20 are mated with each other, the projection-shaped contact portion 13e of the signal contact member 13 is structured to be pressed against the recess-shaped contact portion 23b of the plug connector 20 side, which is the mating counterpart, by part of the insulating housing 11 in which the signal contact member 13 of the receptacle connector (first electric connector) 10 is sandwiched. Therefore, the electric connectivity of the contact portion is enhanced, and impedance matching of signal transmission utilizing the dielectric property of the insulating housing 11 can be expected.
Meanwhile, the signal contact members 13 and 23 provided in the above described both electric connectors 10 and 20 are configured to be electrically connected to each other only by the contact portion at a single location consisting of the projection-shaped contact portion 13e and the recess-shaped contact portion 23b disposed in the connector central side, and signal transmission is configured to be carried out via the contact portion at the single location.
On the other hand, a projection-shaped contact portion 24c is formed at an intermediate position of the up-down-direction extension of the connector outer lateral wall surface of the mating projection portion 24a provided in the power-source contact member 24. The projection-shaped contact portion 24c of the plug connector 20 side is configured to be in a relation in which it contacts and is electrically connected to the recess-shaped contact portion 14f provided in the power-source contact member 14 of the receptacle connector (first electric connector) 10 side when both of the electric connectors 10 and 20 are mated with each other, and, as a result, the mating projection portion 23a of the signal contact member 23 provided in the plug connector (second electric connector) 20 is inserted in the inner space of the mating recessed portion 13a of the signal contact member 13 provided in the above described receptacle connector (first electric connector) 10.
In this manner, the power-source contact members 14 and 24 respectively provided in both of the electric connectors 10 and 20 are configured to be electrically connected to each other via the contact portions at two locations composed of the inner-side contact portion, which is composed of the projection-shaped contact portion 14e and a recess-shaped contact portion 24b disposed in the connector central side, and the outer-side contact portion, which is composed of the recess-shaped contact portion 14f and the projection-shaped contact portion 24c disposed in the connector outer side so that power-source currents are supplied via the contact portions at the two locations.
According to the present embodiment as described above, signal transmission is carried out through the projection-shaped contact portion 13e and the recess-shaped contact portion 23b, which are provided at one location for the mating recessed portion 13a and the mating projection portion 23a of the signal contact members 13 and 23. Therefore, particularly interference in high-frequency transmission is reduced, and good transmission characteristics are obtained. On the other hand, the projection-shaped contact portion 14e and the flat surface portion provided in the mating recessed portion 14a and the mating projection portion 24a of the power-source contact members (or ground contact members) 14 and 24 are brought into a mutually contacted state, and the projection-shaped contact portion 24c and the recess-shaped contact portion 14f are brought into a mutually contacted state, and, therefore, sufficient mating retention force is obtained.
Meanwhile, the lower end parts of the inner wall surfaces of the mating projection portions 23a and 24a provided in the above described signal contact member 23 and the power-source contact member (or ground contact member) 24 are bent at approximately right angle at the lower-surface position of the plug connector 20 toward the connector outer side and are formed into board-connecting leg portions (contact connecting portions) 23c and 24d. The board-connecting leg portions 23c and 24d are extending approximately horizontally toward the connector-width-direction outer side and are configured so as to be solder-joined with signal-transmitting electrically-conductive paths (signal pads) P2a and a power-supplying electrically-conductive paths (power-source pads) P2b on the second wiring board P2 particularly as shown in FIG. 31 in a case of mounting of the plug connector 20. The solder-joining of the board-connecting leg portions 23c and 24d is collectively carried out with respect to all the board-connecting leg portions 23c and 24d by using a solder material having a long shape.
[About Electrically-Conductive Shells of Receptacle Connector]
Next, the electrically-conductive shells 12 provided as the shield wall portions in the receptacle connector (first electric connector) 10 side are formed by a frame-shaped structure divided into two bodies and are attached to the insulating housing 11 in a state in which they are disposed to be opposed so as to face each other. More specifically, each of the pair of electrically-conductive shells (shield wall portions) 12 and 12 is formed by a thin-plate-shaped metal bent member which forms an approximately L-shape in a planar view, the longitudinal lateral wall plate 12a constituting the long-side part of the shape which is approximately L-shaped in a plane in the electrically-conductive shell 12 is disposed so as to extend along the connector longitudinal direction, and the short-side lateral wall plate 12b constituting the short-side part of the shape which is approximately L-shaped in a plane is disposed so as to extend along the connector width direction. The longitudinal lateral wall plates 12a and 12a and the short-side lateral wall plates 12b and 12b constituting the pair of electrically-conductive shells 12 and 12 are disposed in a state in which they are opposed to each other approximately in parallel, and, as a result of such an opposed disposition relation, the frame structure which forms an approximately rectangular shape as an overall shape in a planar view is formed.
Herein, on an upper edge part of the short-side lateral wall plate 12b of the electrically-conductive shell (shield wall portion) 12, a pair of fixation latch pieces 12c and 12c are provided with a predetermined interval therebetween. Each of the fixation latch pieces 12c constitutes an auxiliary cover as described later, is bent so as to bulge from the upper edge part of the short-side lateral wall plate 12b toward the connector central side (inner side), and is then formed into a bent curved shape of a reversed U-shape, which is inverted toward the lower side. When both of the fixation latch pieces 12c and 12c are subjected to press-fitting from the upper side with respect to the base end portion 11a of the above described insulating housing 11, the entire electrically-conductive shell 12 is brought into a fixed state with respect to the insulating housing 11.
On the other hand, on the lower edge portions of the longitudinal lateral wall plates 12a and the short-side lateral wall plates 12b of the electrically-conductive shells (shield wall portions) 12, a plurality of ground connecting portions 12d composed of plate-shaped protruding pieces which project to the lower side toward the surface of the first wiring board P1 are formed. The plate-shaped protruding pieces constituting the ground connecting portions 12d are formed so as to be continuous to have the surfaces which are flat to the longitudinal lateral wall plate 12a or the short-side lateral wall plate 12b and are extending in the plate thickness of the longitudinal lateral wall plate 12a or the short-side lateral wall plate 12b. 
In this manner, in the receptacle connector (first electric connector) 10 according to the present embodiment, the ground connecting portions (plate-shaped protruding pieces) 12d of the electrically-conductive shells (shield wall portions) 12 are disposed in a state in which they are within the range of the plate thickness of the electrically-conductive shells 12 and are configured so as not to bulge to the outer side of the electrically-conductive shells 12. Therefore, the entire connector can be downsized.
Note that the lower end portions of the above described ground connecting portions 12d are electrically connected to ground electrically-conductive paths (ground pads) P1c, which are provided on the surface of the first wiring board P1, by solder-joining therewith, and the solder-joining of the ground connecting portions 12d in that case is collectively carried out for all of the ground connecting portions 12d by using a solder material having a long shape.
Since the electrically-conductive shells (shield wall portions) 12 composed of the frame structures having such an approximately rectangular shape in the plane are formed so as to surround the entire outer periphery of the insulating housing 11, electromagnetic shielding with respect to the signal contact members 13 attached to the insulating housing 11 is carried out.
Particularly, there is a disposition relation that, at the positions having predetermined intervals in the connector width direction from the board-connecting leg portions (contact connecting portions) 13f of the above described signal contact members 13, the longitudinal lateral wall plates 12a of the electrically-conductive shells (shield wall portions) 12 are provided to stand on the surface of the first wiring board P1. More specifically, since the longitudinal lateral wall plates 12a of the electrically-conductive shells 12 are opposed to the outer end surfaces of the board-connecting leg portions 13f of the signal contact members 13 and are extending in the connector longitudinal direction (multipolar-shape arrangement direction), the electromagnetic shielding with respect to the entire signal contact members 13 including the board-connecting leg portions 13f is configured to be carried out well in a state in which impedance matching is appropriately carried out via the spatial parts between the above described board-connecting leg portions 13f and the longitudinal lateral wall plates 12a of the electrically-conductive shells 12.
[About Lateral Check Window]
Meanwhile, the plurality of ground connecting portions (plate-shaped protruding pieces) 12d provided on the longitudinal lateral wall plates 12a of the above described electrically-conductive shells (shield wall portions) 12 are disposed at constant intervals in the connector longitudinal direction (multipolar-shape arrangement direction), and, in the region of the interval between the pair of ground connecting portions 12d and 12d, which are adjacent to each other in the connector longitudinal direction, a lateral check window 12e composed of the space which enables visual check of the board-connecting leg portions (contact connecting portions) 13f of the signal contact member 13 in the connector width direction is formed.
More specifically, the ground connecting portions 12d provided in the electrically-conductive shells (shield wall portions) 12 are in a disposition relation in which the installation positions thereof in the connector longitudinal direction are shifted with respect to the board-connecting leg portions (contact connecting portions) 13f of the signal contact members 13, and there is a relation that the ground connecting portion 12d is disposed in the part between the board-connecting leg portions 13f and 13f which are adjacent to each other in the connector longitudinal direction. In the part between the pair of ground connecting portions 12d and 12d which are adjacent to each other in the connector longitudinal direction, a laterally-long spatial part formed by the ground connecting portions 12d and 12d and the lower edge portion of the longitudinal lateral wall plate 12a of the electrically-conductive shell 12 is formed, and the laterally-long spatial part is formed into the above described lateral check window 12e. 
The connector-longitudinal-direction length of the lateral check window 12e according to the present embodiment is formed to correspond to the length in which the plurality (three) of board-connecting leg portions (contact connecting portions) 13f are juxtaposed. In a case in which an assembly operator carries out a visual check toward the connector width direction through the lateral check window 12e, the end faces of the plurality (three) of board-connecting leg portions 13f are configured to be visually checked in the inner region of the lateral check window 12e. 
[About Planar Cover]
Furthermore, a planar cover 12f, which is approximately horizontally extending, is continued to the upper edge part of the longitudinal lateral wall plate 12a of the above described electrically-conductive shell (shield wall portion) 12. The planar cover 12f is formed so as to be bent approximately at right angle from the upper edge portion of the longitudinal lateral wall plate 12a toward the connector central side (inner side) and is extending approximately horizontally so as to cover, from the upper side, the spatial part which is formed from the longitudinal lateral wall plate 12a to the vicinities of the distal ends of the board-connecting leg portions (contact connecting portions) 13f of the signal contact members 13.
In this manner, according to the present embodiment, the electromagnetic shielding function with respect to the board-connecting leg portions (contact connecting portions) 13f of the signal contact members 13 is obtained well by the electrically-conductive shells (shield wall portions) 12. Particularly, since the electrically-conductive shells 12 of the receptacle connector (first electric connector) 10 according to the present embodiment are provided with the planar covers 12f, which cover the upper surface of the insulating housing 11 approximately in parallel with the first wiring board P1, the electromagnetic shielding function with respect to the board-connecting leg portions 13f is further enhanced by the planar covers 12f. 
The pair of planar covers 12f is disposed in both sides sandwiching the central projecting portion 11b of the insulating housing 11 in the connector width direction so as to be opposed to each other, and a plurality of cover coupling portions 12g are provided on the connector-central-side inner edge part of each of the planar covers 12f so as have constant intervals in the connector longitudinal direction. Each of the cover coupling portions 12g is formed by a plate-shaped protruding piece which is projecting approximately horizontally toward the connector central side, and the cover coupling portions 12g are supported so as to be placed on receiving portions 11f, which are formed so as to form mount shapes on the longitudinal lateral wall portions 11e of the central projecting portion 11b, from the upper side. Since the cover coupling portions 12g like this are provided, reinforcement in a case of insertion/removal of the receptacle connector (first electric connector) 10 and the plug connector (second electric connector) 20 is carried out.
The plate-shaped protruding pieces constituting the cover coupling portions 12g are formed so as to have the surfaces flat to the planar covers 12f and continued therefrom and are extending within the plate thickness of the planar cover 12f. In this manner, the cover coupling portions 12g provided at the planar covers 12f in this manner are disposed in the state in which they are within the range of the plate thickness of the planar covers 12f and do not bulge to the outer side of the planar covers 12f. Therefore, the height of the entire connector can be reduced.
Meanwhile, the plurality of cover coupling portions 12g provided at the planar cover 12f are disposed at constant intervals in the connector longitudinal direction as described above, and, in the region of the interval between the pair of cover coupling portions 12g and 12g which are adjacent to each other in the connector longitudinal direction, a planar test window 12h composed of the space which enables visual check of the board-connecting leg portions (contact connecting portions) 13f of the signal contact members 13 in the downward direction is formed.
More specifically, the cover coupling portions 12g provided in the above described electrically-conductive shells (shield wall portions) 12 are in a disposition relation in which the installation positions thereof in the connector longitudinal direction are shifted with respect to the board-connecting leg portions (contact connecting portions) 13f of the signal contact members 13, and there is a relation that the cover coupling portion 12g is disposed in the part between the board-connecting leg portions 13f and 13f, which are adjacent to each other in the connector longitudinal direction. In the part between the pair of cover coupling portions 12g and 12g, which are adjacent to each other in the connector longitudinal direction, a laterally-long spatial part formed by the cover coupling portions 12g and 12g and the inner edge portion of the planar cover 12f of the electrically-conductive shell 12 is formed, and the laterally-long spatial part is formed into the above described planar check window 12h. 
The connector-longitudinal-direction length of the planar check window 12h according to the present embodiment is formed so as to correspond to the length in which the plurality (three) of board-connecting leg portions (contact connecting portions) 13f are juxtaposed. In a case in which an assembly operator carries out visual check toward the downward direction through the planar check window 12h, the end surfaces of the plurality (three) of board-connecting leg portions 13f are configured to be visually checked in the inner region of the planar check window 12h. 
In this manner, in the present embodiment, through the lateral check windows 12e and the planar check windows 12h provided in the electrically-conductive shells 12, the connection state of the board-connecting leg portions (contact connecting portions) 13f with respect to the signal-transmitting electrically-conductive paths (signal pads) P1a of the first wiring board P1 and the assembly state of the connectors are configured to be checked by visual from the lateral side and the upper side.
[About Contact Pieces]
Furthermore, on the planar cover 12f of the above described electrically-conductive shell 12 and the part bent and extending downward from the planar cover 12f to the longitudinal lateral wall plate 12a, plate-spring-shaped contact pieces 12i, which elastically contact the mating counterpart, are integrally formed so as to be cut and raised therefrom. The plurality of contact pieces 12i are formed at constant intervals in the connector longitudinal direction, the root parts of the plate-spring-shaped members constituting the contact pieces 12i are provided in the planar cover 12f side, and the distal-end parts of the plate-spring-shaped members are formed so as to obliquely bulge toward the connector-width-direction outer side from the outer surface of the longitudinal lateral wall plate 12a. 
There is a disposition relation that, when the plug connector (second electric connector) 20 is mated with the receptacle connector (first electric connector) 10 from the upper side, the distal-end parts of the above described contact pieces 12i elastically contact the electrically-conductive shells of the plug connector 20 (described later) from the inner side. This point will be described later in detail.
Note that each of the above described contact pieces 12i is disposed at the part between the pair of cover coupling portions 12g and 12g, which are adjacent to each other in the connector longitudinal direction. Since the contact pieces 12i are in the disposition relation in which the contact pieces 12i are positionally shifted in the connector longitudinal direction with respect to the cover coupling portions 12g in such a manner, the pressing force applied to the contact pieces 12i does not directly act on the cover coupling portions 12g, and, as a result, the strength of the cover coupling portions 12g is maintained.
[About Mating Guide]
On the other hand, the surface of the planar cover 12f provided at the longitudinal lateral wall plate 12a of the electrically-conductive shell (shield wall portion) 12 in the above described manner is formed into a sliding guide surface which allows mutual contact movement when both of the electric connectors 10 and 20 are to be mated with each other. Moreover, with respect to the surface of the planar cover 12f formed into the sliding guide surface like this, the top surfaces of the fixation latch pieces 12c and 12c continued to the upper edge part of the short-side lateral wall plate 12b of the electrically-conductive shell 12 are disposed so as to be approximately at the same height as the surface of the planar cover 12f, and the top surfaces of the fixation latch pieces 12c are also formed into sliding guide surfaces when both of the electric connectors 10 and 20 are to be mated with each other. In this manner, the fixation latch pieces 12c provided in the electrically-conductive shell 12 are provided with the configuration as the auxiliary cover with respect to the planar cover 12f, and the planar cover 12f and the auxiliary cover 12c constitute a sliding guide surface.
The surfaces of the later-described electrically-conductive shells 22 of the plug connector (second electric connector) 20 are configured to contact, from the upper side, and slide on the planar covers 12f and the auxiliary covers (fixation latch pieces) 12c constituting the sliding guide surface like this, and guiding to a mating position determined in advance is carried out. This point will be also described later in detail.
[About Electrically-Conductive Shells of Plug Connector]
On the other hand, the electrically-conductive shells 22 provided as the shield wall portions in the plug connector (second electric connector) 20 side are also formed by a frame-shaped structure divided into two bodies and are attached to the insulating housing 21 in a state in which they are disposed to be opposed so as to face each other. More specifically, each of the pair of electrically-conductive shells (shield wall portions) 22 and 22 is formed by a bent member of thin-plate-shaped metal forming approximately a U-shape in a planar view, and the longitudinal lateral wall plate 22a constituting the long-side part of the planarly approximately U-shape of each of the electrically-conductive shells 22 is disposed so as to extend along the connector longitudinal direction.
Meanwhile, at connector-longitudinal-direction both-end parts of the above described longitudinal lateral wall plate 22a, fixation latch pieces 22b and 22b, which are bent at approximately right angle toward the electrically-conductive shell 22 of the other side disposed to be opposed thereto, are integrally continued therefrom. The fixation latch pieces 22b and 22b of each of the electrically-conductive shells 22 are extending in the connector width direction and are buried in the base end portions 21a and 21a, which constitute the connector-longitudinal-direction edge parts of the insulating housing 21, by insert molding, thereby causing the entire electrically-conductive shell 22 to be in a state fixed to the insulating housing 21.
Herein, engagement holes 22f for carrying out positioning with respect to the insulating housing 21 and enhancing fixation latch force are formed to penetrate through the fixation latch pieces 22b of each of the above described electrically-conductive shells 22, and latch protrusions 21e provided on the base end portions 21a of the insulating housing 21 are molded so as to be in a state in which they penetrate through the engagement holes 22f of the electrically-conductive shells 22 when the insert molding as described above is carried out.
The longitudinal lateral wall plates 22a and 22a constituting the above described pair of electrically-conductive shells (shield wall portions) 22 and 22 are disposed to be opposed to each other approximately in parallel, and the fixation latch pieces 22b and 22b constituting the short-side lateral wall plates are disposed to face each other in the connector width direction, thereby constituting the frame structure which forms an approximately rectangular shape as an overall shape in a planar view.
In this manner, in the plug connector (second electric connector) 20 side, the frame structure in which the pair of electrically-conductive shells (shield wall portions) 22 and 22 forming an approximately U-shape in a plane are disposed to be opposed to each other is formed. On the other hand, in the above described receptacle connector (first electric connector) 10 side, the frame structure in which the pair of electrically-conductive shells (shield wall portions) 12 and 12 forming an approximately L-shape in a plane are disposed to each other is formed. Therefore, in a state in which both of the electric connectors 10 and 20 are mated with each other, the gaps generated by disposing the electrically-conductive shells 12 and 12 of the receptacle connector 10 side to be opposed to each other are covered by the electrically-conductive shells 22 of the plug connector 20 side from the outer side, and the gaps generated by disposing the electrically-conductive shells 22 and 22 of the plug connector 20 side to be opposed to each other are covered by the electrically-conductive shells 12 of the receptacle connector 10 side from the inner side. As a result, a state in which the entire periphery of the electric connector device is completely covered by the shield wall portions is obtained so that an extremely good shield function is obtained.
On the other hand, a plurality of ground connecting portions 22c, which are composed of plate-shaped protruding pieces projecting to the lower side toward the surface of the second wiring board P2, are formed on the lower edge portions of the longitudinal lateral wall plates 22a and the fixation latch pieces (short-side lateral wall plates) 22b of the electrically-conductive shells (shield wall portions) 22. The plate-shaped protruding piece constituting each of the ground connecting portions 22c is formed so as to have the surface flat to the longitudinal lateral wall plate 22a or the fixation latch piece (short-side lateral wall plate) 22b and continued, and the plate-shaped protruding piece is extending within the plate thickness of the longitudinal lateral wall plate 22a or the fixation latch piece (short-side lateral wall plate) 22b. 
In the plug connector (second electric connector) 20 according to the present embodiment like this, the fixation latch pieces (short-side lateral wall plates) 22b provided at both-end parts of the longitudinal lateral wall plates 22a of the electrically-conductive shells (shield wall portions) 22 are subjected to insert molding so as to be buried in the base end portions 21a of the insulating housing 11. Therefore, the electrically-conductive shells 22 disposed in the state in which the electrically-conductive shells 22 are housed within the range of the total length of the insulating housing 21 do not bulge to the outer side of the insulating housing 21 so that the entire connector is downsized in the connector longitudinal direction. In addition, in the present embodiment, the ground connecting portions (plate-shaped protruding pieces) 22c of the electrically-conductive shells (shield wall portions) 22 are disposed in the state in which they are within the range of the plate thickness of the electrically-conductive shells 22. Therefore, the ground connecting portions 22c do not bulge to the outer side of the electrically-conductive shells so that the entire connector is further downsized also in the connector width direction.
Note that the lower end portions of the above described ground connecting portions 22c are electrically connected when they are solder-joined with ground electrically-conductive paths (ground pads) P2c provided on the surface of the second wiring board P2, and the solder-joining of the ground connecting portions 22c in this case is collectively carried out with respect to all of the ground connecting portions 22c by using a solder material having a long shape.
Since the electrically-conductive shells (shield wall portions) 22 composed of the frame structure having the planarly approximately rectangular shape like this is formed so as to surround the entire outer periphery of the insulating housing 21, electromagnetic shielding with respect to the signal contact members 23 attached to the insulating housing 21 is carried out.
Particularly, the longitudinal lateral wall plate 22a of the electrically-conductive shell (shield wall portion) 22 is in a disposition relation in which the longitudinal lateral wall plate 22a stand on the surface of the second wiring board P2 at a position that has a predetermined interval in the connector width direction from the board-connecting leg portions (contact connecting portions) 23c of the above described signal contact members 23. More specifically, since the longitudinal lateral wall plate 22a of the electrically-conductive shell 22 is opposed to the outer end surfaces of the board-connecting leg portions 23c of the signal contact members 23 and is extending in the connector longitudinal direction (multipolar-shape arrangement direction), the electromagnetic shielding with respect to the entire signal contact members 23 including the board-connecting leg portions 23c is configured to be carried out well in a state in which impedance matching is appropriately carried out via the spatial part between the above described board-connecting leg portions 23c and the longitudinal lateral wall plate 22a of the electrically-conductive shell 22.
As described above, in the present embodiment, in each of the receptacle connector (first electric connector) 10 and the plug connector (second electric connector) 20, the electromagnetic shielding function with respect to the board-connecting leg portions (contact connecting portions) 13f or 23c is configured to be obtained by the electrically-conductive shells 12 or 22 provided as the shield wall portions thereof. When both of the electric connectors 10 and 20 are mated with each other, the electrically-conductive shells 12 and 22 are doubly disposed inside/outside, and the gap formed between the shield wall portion formed by one of the electrically-conductive shells 12 and 22 and one of the wiring boards P1 and P2 is partially covered by the shield wall portion formed by the other one of the electrically-conductive shells 12 and 22. Therefore, an extremely good shielding function is obtained as the electric connector device. Particularly, since the gaps between the electrically-conductive shells 12 and 22 and the first and second wiring boards P1 and P2 can be efficiently blocked, sufficient EMI measured can be expected.
[About Lateral Check Windows]
Meanwhile, the plurality of ground connecting portions (plate-shaped protruding pieces) 22c provided on the longitudinal lateral wall plate 22a of the above described electrically-conductive shell (shield wall portion) 22 are disposed at the constant intervals in the connector longitudinal direction (multipolar-shape arrangement direction), and, in the region of the interval between the pair of ground connecting portions 22c and 22c adjacent to each other in the connector longitudinal direction, a lateral check window 22d composed of the space that enables visual check of the board-connecting leg portions (contact connecting portions) 23c of the signal contact members 23 toward the connector width direction is formed.
More specifically, each of the ground connecting portions 22c provided in the above described electrically-conductive shell (shield wall portion) 22 is in a disposition relation in which the installation position thereof in the connector longitudinal direction is shifted with respect to the board-connecting leg portions (contact connecting portions) 23c of the signal contact members 23, and there is a relation that the ground connecting portion 22c is disposed in the part between the board-connecting leg portions 23c and 23c, which are adjacent to each other in the connector longitudinal direction. In the part between the pair of ground connecting portions 22c and 22c adjacent to each other in the connector longitudinal direction, a laterally-long spatial part formed by the ground connecting portions 22c and 22c and the lower edge portion of the longitudinal lateral wall plate 22a of the electrically-conductive shell 22 is formed, and the laterally-long spatial part is formed into the above described lateral check window 22d. 
The length of the lateral check window 22d according to the present embodiment in the connector longitudinal direction is formed so as to correspond to the length in which the plurality (three) of board-connecting leg portions (contact connecting portions) 23c are juxtaposed so that, when the assembly operator carries out visual check toward the connector width direction through the lateral check window 22d, the end surfaces of the plurality (three) of board-connecting leg portions 23c can be visually checked in the inner region of the lateral check window 22d. 
In this manner, also in the plug connector (second electric connector) 20 according to the present embodiment, the connection state of the board-connecting leg portions (contact connecting portions) 23c with respect to the signal-transmitting electrically-conductive paths (signal pads) P2a of the second wiring board P2 and the assembly state of the connectors can be visually checked from the lateral side through the lateral check windows 22d provided in the electrically-conductive shells 22.
Meanwhile, when both of the electric connectors 10 and 20 are mated with each other, the electrically-conductive shells (shield wall portions) 22 provided in the plug connector (second electric connector) 20 like this are disposed so as to cover the entire outer periphery of the receptacle connector (first electric connector) 10 from the outer side. In that process, there is a disposition relation that the inner wall surfaces of the electrically-conductive shells 22 of the plug connector 20 elastically contact the distal-end parts of the contact pieces 12i, which are provided in the electrically-conductive shells 12 of the above described receptacle connector 10, from the outer side. As a result, both of the electrically-conductive shells 12 and 22 are caused to be in an electrically ground connection state.
More specifically, in the present embodiment, when both of the electric connectors 10 and 20 are mated with each other, an electrically ground connection is established through the contact pieces 12i provided in the electrically-conductive shells (shield wall portions) 12 of the receptacle connector (first electric connector) 10. Therefore, ground resistance is reduced, and, corresponding to that, shield characteristics are improved.
[About Mating Guide]
On the other hand, the upper edge parts of the longitudinal lateral wall plates 22a of the above described electrically-conductive shells (shield wall portions) 22 are formed into sliding guide surfaces which allow mutual contact movement when both of the electric connectors 10 and 20 are mated with each other. The longitudinal lateral wall plates 22a serving as the sliding guide surfaces are in a disposition relation in which they can contact, from the upper side, the planar covers 12f, which are provided so as to similarly form the sliding guide surfaces on the electrically-conductive shells 12 of the above described receptacle connector (first electric connector) 10. As shown in FIG. 27 to FIG. 29, positioning with respect to the mating positions determined in advance is configured to be carried out by causing the longitudinal lateral wall plates 22a of the electrically-conductive shells 22 of the up/down-inverted plug connector (second electric connector) 20 to be in a state in which they are disposed to contact, from the upper side, the planar covers 12f of the electrically-conductive shells 12 of the receptacle connector (first electric connector) 10 disposed in the lower side and carrying out relative sliding in the state in which the contact disposition is maintained.
Herein, in the corner regions at the four corners of the electrically-conductive shells (shield wall portions) 22 provided in the plug connector (second electric connector) 20, in other words, at the parts at which the longitudinal lateral wall plates 22a and the fixation latch pieces 22b constituting the short-side lateral wall plates are coupled, in total, four positioning portions 22e which regulate both of the electric connectors 10 and 20 to the mating positions are provided. Each of the positioning portions 22e is formed by a mount-shaped projection-shaped part projecting from the upper edges of the longitudinal lateral wall plate 22a and the fixation latch piece (short-side lateral wall plate) 22b to form a step, and the positioning portion is formed so as to extend in the connector longitudinal direction and the connector width direction along the coupling shape of the longitudinal lateral wall plate 22a and the fixation latch piece (short-side lateral wall plate) 22b and form an approximately L-shape in a plane.
When relative sliding is carried out in the state in which the longitudinal lateral wall plates 22a of the electrically-conductive shells 22 of the plug connector (second electric connector) 20 are disposed to contact, from the upper side, the planar covers 12f of the electrically-conductive shells 12 of the receptacle connector (first electric connector) 10 disposed in the lower side in the above described manner to reach the mating positions determined in advance, the positioning portions 22e provided on the electrically-conductive shells 22 in the plug connector 20 side fit in the four corner portions of the electrically-conductive shells 12 of the receptacle connector 10 side from the outer side, and positioning of the mating positions is configured to be carried out as a result.
Note that, in the state in which both of the electric connectors 10 and 20 are mated with each other, the positioning portions 22e provided on the electrically-conductive shells 22 of the plug connector (second electric connector) 20 are disposed to be opposed to the surface of the first wiring board P1 on which the receptacle connector (first electric connector) 10 is mounted, wherein no electrically-conductive path, etc. are formed on the surface of the first wiring board P1 on which the positioning portions 22e are disposed to be opposed thereto. Therefore, even when the heights of both of the electric connectors 10 and 20 are reduced, a situation in which the positioning portions 22e contacts the surface of the first wiring board P1 upon mating is configured to be avoided.
In this manner, in the present embodiment, when both of the electric connectors 10 and 20 are to be mated with each other, they are relatively moved while the sliding surfaces 12f and 22a of the electrically-conductive shells 12 and 22 of both of the electric connectors 10 and 20 are in contact with each other. Therefore, the relative movement of the electric connectors 10 and 20 is carried out well in a low friction state.
When the relative movement between the electric connectors 10 and 20 as described above is carried out, the sliding guide surfaces 12f and 22a composed of electrically-conductive members such as metal are brought into a mutually contacted state. Therefore, compared with the contact state of other materials such as resin, problems in terms of usage durability such as scraping and breakage do not easily occur.
Furthermore, when movement to the final mating positions is carried out, the positions are regulated by the positioning portions 22e provided on the electrically-conductive shells (shield wall portions) 22. Therefore, the mating operation is smoothly carried out.
Hereinabove, the invention accomplished by the present inventor has been described in detail based on the embodiment. However, the present invention is not limited to the above described embodiment, and it goes without saying that various modifications can be made within a range not departing from the gist thereof.
For example, the plate-spring-shaped members constituting the contact pieces 12i in the above described embodiment can be configured to provide the base-end parts of the root side on the longitudinal lateral wall plates 12a and to provide the distal-end parts of the contact pieces 12i in the planar cover 12f side. Furthermore, the connection counterparts of the contact pieces 12i are not limited to the counterpart connector, and, for example, a configuration in which they are connected with an electrically-conductive chassis of a device can be also employed.
Moreover, the power-source contact members 14 and 24 in the above described embodiment can serve as ground contact members for grounding.
Furthermore, the recess/projection mating relations between the contact members 12 and 22 in the above described embodiment can be disposed in reversed relations between the receptacle connector 10 and the plug connector 20.
As described above, the present invention can be widely applied to various board-connecting electric connector devices used in various electronic/electric devices.

## Claims

1. A board-connecting electric connector having a plurality of signal contact members arranged in a multipolar shape and a power-source contact member or a ground contact member attached to an insulating housing, the board-connecting electric connector configured so that contact portions provided on the signal contact members and the power-source contact member or the ground contact member are electrically connected to contact portions provided on a mating counterpart; the board-connecting electric connector comprising:
the signal contact members and the power-source contact member or the ground contact member each being provided with a mating recessed portion receiving the mating counterpart and provided with a solder connection portion extending from the mating recessed portion in a direction orthogonal to a direction of arrangement of the multipolar shape;
the contact portion of the signal contact member being provided at a single location for each mating recessed portion of each of the signal contact members; and
the contact portions of the power-source contact member or the ground contact member being provided at a plurality of locations for the mating recessed portion of the power-source contact member or the ground contact member integrated therewith.

2. The board-connecting electric connector according to claim 1, wherein
the power-source contact member or the ground contact member is disposed at an outer position in the direction of arrangement of the multipolar shape of the plurality of signal contact members.

3. The board-connecting electric connector according to claim 1, wherein
the signal contact member is configured so as to sandwich the mating counterpart by the contact portion and part of the insulating housing when mated with the mating counterpart.

4. The board-connecting electric connector according to claim 1, wherein
the signal contact member and the power-source contact member or the ground contact member are formed by band-plate-shaped members having predetermined width sizes in the direction of arrangement of the multipolar shape; and
the width size of the band-plate-shaped member constituting the power-source contact member or the ground contact member is formed to be larger than the width size of the band-plate-shaped member constituting the signal contact member.

5. The hoard-connecting electric connector according to claim 1, wherein
the power-source contact member or the ground contact member has the contact portions at two locations; and
one of the contact portions at the two locations is formed into a lock portion that becomes a mechanically latched state when mated with the mating counterpart.