Patent Publication Number: US-9413089-B2

Title: Connector, and header and socket included in the same

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from prior Japanese Patent Application P2013-132247 filed on Jun. 25, 2013; the entire contents of which are incorporated by reference herein. 
     BACKGROUND OF THE INVENTION 
     The present invention relates to a connector, and a header and a socket which are included in the connector. 
     As shown in Japanese Patent Laid-open Publication No. 2005-019144 (hereinafter, referred to as Patent Literature 1), a conventionally-known connector includes: a socket having plural socket terminals on a socket body; and a header including plural header terminals on a header body. 
     In Patent Literature 1, the socket and header are fitted to each other to bring the socket terminals and header terminals into contact and conduction, thus electrically connecting conductor patterns of the circuit boards connected to the terminals. 
     SUMMARY OF THE INVENTION 
     However, in the aforementioned conventional technique, one each of fixed terminals of a holding bracket attached and fixed to the circuit board is provided at respective four corners of the housing. It is, therefore, difficult to increase the fixation strength of the connector on the circuit boards. 
     Accordingly, an object of the present invention is to provide a connector which can improve in strength of fixation on the circuit board, and a header and a socket which are included in the connector. 
     A first aspect of the present invention is a connector, including: a substantially rectangular housing made of an insulating material; a plurality of terminals which are provided for the housing and are attached to a circuit board to be electrically connected to the circuit board; and a holding bracket which is provided for the housing and is fixed on the circuit board, in which the holding bracket includes a first fixed terminal fixed on the circuit board, and a second fixed terminal which is formed separately from the first fixed terminal and is fixed on the circuit board. 
     A second aspect of the present invention is the connector, wherein the second fixed terminal is extended from the side plate portion of the holding bracket. 
     A third aspect of the present invention is the connector, wherein at least a part of the holding bracket is exposed along the housing. 
     A fourth aspect of the present invention is the connector, wherein the second fixed terminal is provided at a position where the distance from the first fixed terminal on the holding bracket is maximized. 
     A fifth aspect of the present invention is the connector, wherein the holding bracket is provided for the housing by insert molding. 
     A sixth aspect of the present invention is the connector, wherein the housing fills a part between a surface of the holding bracket exposed in an end face of the housing in the longitudinal direction and the surface thereof exposed in an end face thereof in the short-side direction. 
     A seventh aspect of the present invention is a socket included in the connector. 
     An eighth aspect of the present invention is a header included in the connector. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a socket of a connector according to an embodiment of the present invention seen from the front side. 
         FIG. 2  is a perspective view of the socket of the connector according to the embodiment of the present invention seen from the back side. 
         FIGS. 3A to 3D  are views illustrating the socket of the connector according to the embodiment of the present invention,  FIG. 3A  being a planar view,  FIG. 3B  being a side view,  FIG. 3C  being a back view, and  FIG. 3D  being a front view. 
         FIG. 4  is an enlarged perspective view of a part of the socket of the connector according to the embodiment of the present invention. 
         FIGS. 5A and 5B  are perspective views of a socket holding bracket of the connector according to the embodiment of the present invention seen from the front side. 
         FIGS. 6A and 6B  are perspective views of the socket holding bracket of the connector according to the embodiment of the present invention seen from the back side. 
         FIG. 7  is a perspective view of an unfolded state of the socket holding bracket of the connector according to the embodiment of the present invention. 
         FIG. 8  is a perspective view of a header of the connector according to the embodiment of the present invention seen from the back side. 
         FIG. 9  is a perspective view of the header of the connector according to the embodiment of the present invention seen from the front side. 
         FIGS. 10A to 10D  are views illustrating the header of the connector according to the embodiment of the present invention,  FIG. 10A  being a back view,  FIG. 10B  being a side view,  FIG. 10C  being a planar view, and  FIG. 10D  being a front view. 
         FIG. 11  is a cross-sectional view of the connector according to the embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Hereinafter, a description is given in detail of an embodiment of the present invention with reference to the drawings. In the following description, the width direction (the short-side direction) of a connector is referred to as a direction X; the longitudinal direction of the connector, a direction Y; and the top-bottom direction of the connector in  FIG. 11 , a direction Z. In the description of the socket and header, the upper sides of the socket and header in the state illustrated in  FIG. 11  are referred to as an upper side (a front side) in the top-bottom direction, and the lower sides thereof are referred to as a lower side (a back side) in the top-bottom direction. 
     A connector  10  according to the embodiment includes a socket  20  and a header  70  fitted to each other as illustrated in  FIG. 11 . In the embodiment, the socket  20  includes a socket fitting body  40  which is provided with socket terminals  30 , and the header  70  includes a header fitting body  90  provided with header terminals  80 . 
     The socket fitting body  40  (a socket fitting portion of a later-described socket housing  50 ) and the header fitting body  90  (a header fitting portion of a later-described header housing  100 ) are fitted to each other to bring the socket terminals  30  and header terminals  80  into contact (see  FIG. 11 ). 
     The socket  20  is attached to a first circuit board  130 , and the header  70  is attached to a second circuit board  140 . 
     When the socket  20  and header  70  are fitted to each other, therefore, the first circuit board  130  attached to the socket  20  is electrically connected to the second circuit board  140  attached to the header  70 . 
     In the embodiment, as illustrated in  FIGS. 1 to 3D , the socket fitting body  40  includes the socket housing  50  which is molded with insulating synthetic resin and has a rectangular (oblong) planar view. The socket fitting body  40  further includes socket holding brackets  60  provided at both ends of the socket housing  50  in the longitudinal direction Y. 
     The socket housing  50  is provided with the plural socket terminals  30  arranged at predetermined intervals in the longitudinal direction Y. In the embodiment, the plural socket terminals  30  are arranged in a single line in the longitudinal direction Y of the socket housing  50 . In other words, a socket terminal group  30 G including the plural socket terminals  30  arranged in the longitudinal direction Y of the socket housing  50  is provided only in a single line in the socket housing  50 . 
     The socket terminal group  30 G includes the plural socket terminals  30  arranged in such a manner that the socket terminals  30  with later-described socket main contacts  37  located on one side of the socket housing  50  in the width direction X and the socket main contacts  37  of the socket terminals  30  located on the other side are alternately located. 
     The socket housing  50  includes a plate-shaped wall portion  56  and a circumferential wall portion  51  continuously formed along the peripheral edge of the plate wall portion  56  and is formed in a substantially box shape open at one side (the upper side). Inside the circumferential wall portion  51 , a fitting groove portion (a socket fitting portion)  52  for fitting of the header  70  is formed. 
     Furthermore, in the embodiment, tapered portions  51   e  are formed in the upper inside edge of the circumferential wall portion  51 . Each of the tapered portions  51   e  inclines downward (toward the plate-shaped wall portion  56 ) toward the inside. The tapered portions  51   e  are formed on the short sides of the circumferential wall portion  51  and on both ends of each long side thereof in the longitudinal direction. The tapered portions  51   e  are also formed individually between the socket terminals  30  adjacent to each other and individually between the socket terminals  30  and the socket holding brackets  60 . In this embodiment, the tapered portions  51   e  are formed on the substantially entire circumference of the circumferential wall portion  51 . 
     The fitting groove portion (the socket fitting portion)  52  includes a narrow socket terminal group housing portion  52   a  which is formed at the center in the longitudinal direction Y and is provided with the socket terminal group  30 G located so as to be exposed inside. 
     The fitting groove portion (socket fitting portion)  52  of the socket housing  50  includes socket wide portions  52   b  in the outside (the region corresponding to each header wide portion  102   b ) in the longitudinal direction Y, of the region (the socket terminal group housing portion  52   a ) where the socket terminal group  30 G is provided. The socket wide portions  52   b  are wider than the region (the socket terminal group housing portion  52   a ) where the socket terminal group  30 G is provided. 
     In the embodiment, the socket wide portions  52   b  are formed at both ends of the socket terminal group housing portion  52   a  in the longitudinal direction Y. The fitting groove portion (the socket fitting portion)  52  has a substantially I-shaped planar view with the socket terminal group housing portion  52   a  and the socket wide portions  52   b  at the both ends of the same. 
     The socket terminals  30  can be formed by bending a metallic belt material with a predetermined thickness, for example. In the embodiment, as illustrated in  FIG. 11 , each socket terminal  30  includes a U-shaped portion  31  including both sidewall portions  31   a ,  31   a  and a connecting portion  31   b  into an inverted U shape. At the end of one of the sidewall portions  31   a  (the right sidewall portion in  FIG. 11 ) of the U-shaped portion  31 , the socket terminal  30  is bent about a first bent portion  32  and is extended in the horizontal direction as a horizontal portion  33 . At the end of the horizontal portion  33 , the socket terminal  30  is bent upward about a second bent portion  34  as an inclined piece portion  35 . At the end of the inclined piece portion  35 , the socket terminal  30  is further bent upward about a third bent portion  36  and is bent toward the inside of the socket housing  50  (toward the center in the width direction) to form a socket main contact portion  37  having an inverted U-shape. In the embodiment, in other words, the socket main contact portion  37  (at least one of the socket and header terminals) includes a foot portion  37   a  standing upward from the third bent portion  36  and a contact  37   b  which is extended from the upper end of the foot portion  37   a  toward the inside of the socket housing  50  and comes into contact with an engagement recess portion (a header main contact portion)  84 . The socket main contact portion  37  is configured to elastically deform about the third bent portion  36  with respect to the inclined piece portion  35 . 
     In the embodiment, the inclined piece portion  35  is also configured to elastically deform about the second bent portion  34 . Since the inclined piece portion  35  is configured to elastically deform as well as the socket main contact portion  37 , the places where stress can be concentrated in the process of elastic deformation is increased in number, and the stress can be distributed. This can more reliably prevent the socket terminals  30  from wearing. 
     On the other hand, at the end of the other sidewall portion  31   a  (the left sidewall portion  31   a  in  FIG. 11 ) of the U-shaped portion  31 , the socket terminal  37  is bent about a fourth bent portion  38  and extended in the horizontal direction to form a flat socket connection terminal portion  39 . 
     In the embodiment, as illustrated in  FIGS. 1 to 3D and 11 , the socket terminals  30  are attached to the socket housing  50  so that the socket main contact portions  37  may protrude into the fitting groove portion (socket fitting portion)  52 . The U-shaped portions  31  and socket main contact portions  37  are, respectively, fitted into recess portions  51   a  and  51   b  formed on both sides of the circumferential wall portion  51  in the width direction. The recess portions  51   a  and  51   b  are alternately formed along the longitudinal direction Y in both sides of the circumferential wall portion  51  in the width direction. 
     With the U-shaped portions  31  and socket main contact portions  37  fitted in the recess portions  51   a  and  51   b , respectively, the socket connection terminal portions  39  of the socket terminals  30  protrude outward in the width direction X from the foot (the lower edge) of the circumferential wall portion  51 . The socket connection terminal portions  39  are connected to the conductor patterns (terminals) of the first circuit board  130  by soldering or the like. The socket terminals  30  are thus electrically connected to the first circuit board  130 . In the embodiment, the socket connection terminal portions  39  are formed on the opposite side in the width direction X to the socket main contact portions  37  with respect to the U-shaped portions  31 . The plural socket terminals  30  are arranged in the longitudinal direction Y side by side in such a manner that the socket terminals  30  with the socket main contact portions  37  located in one side in the width direction X of the socket housing  50  with respect to the U-shaped portions  31  and the socket terminals  30  with the socket main contact portions  37  located on the other side are alternately located. The socket connection terminal portions  39  therefore alternately protrude toward one side and toward the other side in the width direction X (see  FIGS. 2 to 3D ). 
     In such a manner, the socket terminal group  30 G is formed so that the socket terminals  30  with the socket connection terminal portions  39  protruded on one side of the socket housing  50  in the width direction X and the socket terminals  30  with the socket connection terminal portions  39  protruded to the other side are alternately located in the embodiment. 
     In the assembly of the socket  20 , the socket terminals  30  are inserted (press-fitted) from the back of the socket housing  50  (from the lower side in  FIG. 11 ) to be attached to the socket housing  50  (socket fitting body  40 ). 
     When the socket terminals  30  are inserted (press-fitted) from the back (the lower side in  FIG. 11 ) of the socket housing  50  in such a manner, the socket terminals  30  can be attached to the socket housing  50  (the socket fitting body  40 ) without interfering with later-described protrusion portions  51   c.    
     In other words, even if the socket housing  50  includes the protrusion portions  51   c , which can come into contact with protrusion portions  103  formed in a header housing  100 , the socket terminals  30  can be attached to the socket housing  50  (the socket fitting body  40 ) by insertion (press-fitting). 
     Accordingly, it is possible to easily produce the socket  20  which can be prevented from rattling when the socket is fitted to the header  70 . 
     As described above, in the embodiment, the recess portions  51   a , to which the U-shaped portions  31  are fitted, and the recess portions  51   b , to which the socket main contact portions  37  are fitted, are alternately formed in the longitudinal direction Y in both sides of the circumferential wall portion  51  in the width direction. In order to fit the U-shaped portions  31  into the respective recess portions  51   a  and the socket main contact portions  37  into the respective recess portions  51   b , therefore, the plural socket terminals  30  are inserted into the socket housing  50  so that the socket terminals  30  adjacent to each other are reversed from each other by 180 degrees about the axis (a vertical axis passing through the center of the socket housing  50  in the width direction in  FIG. 11 ) extending in the vertical direction (the direction Z). 
     In other words, the plural socket terminals  30  have the same shape and are attached from an end to the other end to the socket housing  50  (the socket fitting body  40 ) in the longitudinal direction (the direction Y) so as to be alternately reversed. Accordingly, the socket terminal  30  adjacent to the socket terminal  30  illustrated in  FIG. 11  has a reversed shape so that the contact portion  37  may be in contact with the left side of the wall portion (the header fitting portion)  102 , one of the sidewall portions  31   a  may be in contact with the right side of the wall portion (the header fitting portion)  102 , and the socket connection terminal portion  39  may protrude rightward. 
     The socket terminals  30  may be attached to the socket housing  50  (the socket fitting body  40 ) by insert-molding or the like. 
     As described above, each socket main contact portion  37  having an inverted U-shape includes: the foot portion  37   a  standing upward from the third bent portion  36 ; and the contact  37   b  which is extended from the upper end of the foot portion  37   a  toward the inside of the socket housing  50  and comes into contact with an engagement recess portion (a header main contact portion)  84 . The contact  37   b  has a shape extended from the upper end of the foot portion  37   a  toward the inside of the socket housing  50  as described above, so that the spring length of the socket main contact portion  37  is increased. Compared with the case where the upper end of the foot portion  37   a  is extended toward the outside of the socket housing  50 , the increase in spring length makes more flexible the socket main contact portion  37 , thus increasing the fitting reliability. 
     Furthermore, in the embodiment, the socket main contact portion  37  having an inverted U-shape is turned about the third bending portion  36  toward the inside of the socket housing  50  (the upper end of the foot portion  37   a  is located more inward than the lower end) so as to minimize the length of each socket terminal  30  in the width direction (the width in the direction X). 
     The above described shape of the socket terminals  30  allows the wall portion (header fitting portion)  102  to be fitted into the U-shaped portion  31 A in the state where the wall portion  102  is lopsided toward one side (the sidewall portion  31   a  side) of the U-shaped portion  31 A, which includes one of the sidewall portions  31   a  (the right sidewall portion  31   a  in  FIG. 11 ), horizontal portion  33 , inclined piece portion  35 , and foot portion  37   a . In other words, the center in the width direction (the direction X), of a lower connecting portion  31   a A (the region between the first bent portion  32  and the third bent portion  36 ) of the U-shaped portion  31 A, which includes the horizontal portion  33  and inclined piece portion  35 , is located away from the center in the width direction (the direction X), of the wall portion (the header fitting portion)  102  on one side (the sidewall portion  31   a  side) in the width direction (the direction X). 
     Accordingly, as illustrated in  FIG. 3A , the socket terminals  30  adjacent to each other are arranged in the socket housing  50  so that the centers of the U-shaped portions  31 A in the width direction (the direction X), more specifically, the centers in the width direction (the direction X), of the lower connecting portions  31   a A (the regions between the first bent portions  32  and the corresponding third bent portions  36 ) are not aligned in the same line in the longitudinal direction (the direction Y) in the embodiment. 
     As illustrated in  FIG. 3A , in every second one of the plural socket terminals  30 , the centers of the U-shaped portions  31 A in the width direction (the direction X) are aligned on the same line in the longitudinal direction (the direction Y). 
     To be more specific, the socket terminals  30  at the odd numbered positions from an end in the longitudinal direction (the direction Y) are arranged so that the centers of the U-shaped portions  31 A in the width direction (the direction X) are aligned on the same line in the longitudinal direction (the direction Y). The socket terminals  30  at the even numbered positions from the same end in the longitudinal direction (the direction Y) are arranged so that the centers of the U-shaped portions  31 A in the width direction (the direction X) are aligned on the same line in the longitudinal direction (the direction Y). The line extending in the longitudinal direction (the direction Y) through the centers of the U-shaped portions  31 A of the socket terminals  30  located at the even numbered positions is offset in the width direction (the direction X) from the line extending in the longitudinal direction (the direction Y) through the centers of the U-shaped portions  31 A of the socket terminals  30  located at the odd numbered positions. 
     On the other hand, as illustrated in  FIGS. 8 to 10D , the header fitting body  90  includes the header housing  100 , which is molded with insulating synthetic resin into a rectangular (oblong) as a whole in a planar view. The header fitting body  90  includes header holding brackets  110  provided at both ends of the header housing  100  in the longitudinal direction Y. 
     In the header housing  100 , the plural header terminals  80  are arranged in the longitudinal direction Y at the same intervals (predetermined intervals) as those of the socket terminals  30 . In the embodiment, the plural header terminals  80  are arranged in a single line in the longitudinal direction Y of the header housing  100 . In other words, the header terminal group  80 G including the plural header terminals  80  arranged in the longitudinal direction Y of the header housing  100  is provided in a single line in the header housing  100 . 
     The header housing  100  includes: a plate-shaped wall portion  101 ; and a wall portion (a header fitting portion)  102  which protrudes downward in the center of the plate-shaped wall portion  101  and is fitted into the fitting groove portion (the socket fitting portion)  52 . At the lower outside edge of the wall portion (the header fitting portion)  102 , tapered portions  102   d  are formed so as to incline upward (toward the plate-shaped wall portion  101 ) toward the outside. The tapered portions  102   d  are formed at the short sides of the wall portion (the header fitting portion)  102  and at the both ends of each long side thereof in the longitudinal direction. 
     The wall portion (the header fitting portion)  102  includes a narrow header terminal group arrangement portion  102   a  which is formed at the center in the longitudinal direction Y and is provided with the header terminal group  80 G. 
     The wall portion (the header fitting portion)  102  of the header housing  100  includes header wide portions  102   b  in the outside in the longitudinal direction Y, of the region (the header terminal group arrangement portion  102   a ) where the header terminal group  80 G is provided. The header wide portions  102   b  are wider than the region (the header terminal group arrangement portion  102   a ) where the header terminal group  80 G is provided. 
     In the embodiment, the header wide portions  102   b  are formed on both sides of the header terminal group arrangement portion  102   a  in the longitudinal direction Y. The wall portion (the header fitting portion)  102  has a substantially I-shaped planar view formed by the header terminal group arrangement portion  102   a  and the header wide portions  102   b  at both ends thereof. 
     Each header terminal  80  can also be formed by bending a metallic belt material with a predetermined thickness in a similar manner to the socket terminals  30 . As illustrated in  FIG. 11 , each header terminal  80  includes a U-shaped portion  81  having both-sidewall portions  81   a  and  81   a  and a connecting portion  81   b  and has an inverted U-shape. The header terminal  80  further includes a flat portion  81   c  in the outer side of the connecting portion  81   b  (at the lower side in  FIG. 11 ). 
     At the ends of both sidewall portions  81   a  of the U-shaped portion  81  are formed substantially flat header connection terminal portions  83 . Each header connection terminal portion  83  is turned about a fourth bent portion  82  and is extended in the horizontal direction. 
     In such a manner, in the embodiment, each header terminal  80  includes the header connection terminal portions  83  which protrude toward the outside of the header housing  100  and is attached to the second circuit board  140 . The header connection terminal portions  83  protrude from both sides of the header terminal  80  in the width direction X of the header housing  100 . 
     Accordingly, the header terminal group  80 G includes the header terminals  80  with the header connection terminal portions  83  protruding to one side in the width direction of the header housing  100  and the header terminals  80  with the header connection terminal portions  83  protruding to the other side. 
     The header terminals  80  are provided for the header housing  100  so that the U-shaped portions  81  may cover the top portion (the lower side in  FIG. 11 ) of the wall portion (the header fitting portion)  102 . The header terminals  80  are attached to the header housing  100  by insert molding. In this state, the header connection terminal portions  83  of each header terminal  80  are protruded outward in the direction X (the width direction) from the lower edge of the wall portion (the header fitting portion)  102  and are connected to conductor patterns (terminals) of the second circuit board  140  by soldering. The header terminals  80  are thus electrically connected to the second circuit board  140 . The header terminals  80  may be press-fitted into the header housing  100  to be provided for the header housing  100  (the header fitting body  90 ). 
     As illustrated in  FIG. 11 , the header  70  is fitted to the socket  20  by inserting and fitting the wall portion (the header fitting portion)  102  of the header housing  100  into the fitting groove portion  52  of the socket housing  50 . Accordingly, in the embodiment, one side (the upper side: the opening side) of the socket housing  50  corresponds to the side of the socket fitting body  40  which is fitted to the header fitting body  90 , and the plate-shaped wall portion  56  is formed on the opposite side (the other side (the lower side) of the socket housing  50 ) to the side of the socket fitting body  40  which is fitted to the header fitting body  90 . On the other hand, one side of the header housing  100  (the lower side: the protruding side) corresponds to the side of the header fitting body  90  which is fitted to the socket fitting body  40 . 
     In the process of fitting the header  70  to the socket  20 , for example, the tapered portions  51   e  and  102   d  formed on the long sides at one end in the direction X (the width direction: the short-side direction) are laid on each other and moved to the other end in the direction X (the width direction: short-side direction) for fitting. This allows the tapered portions  51   e  and  102   d  to function as a guiding portion, thus facilitating fitting of the header  70  and socket  20  to each other. 
     In the state where the header  70  is fitted to the socket  20 , an outer surface F 1  of the socket main contact portion  37  of each socket terminal  30  is in elastic contact with an outer surface F 2  of one of the sidewall portions  81   a  of the corresponding header terminal  80 . On the other hand, an outer surface F 3  of the sidewall portion  31   a  of each socket terminal  30  is in elastic contact with an outer surface F 4  of the other sidewall portion  81   a  of the header terminal  80 . The socket terminal  30  and header terminal  80  are, therefore, electrically connected to each other, so that the conductor patterns of the first circuit board  130  are thus electrically connected to the conductor patterns of the second circuit board  140 . 
     In the embodiment, the outer surface F 2  of one of the sidewall portions  81   a  is the inner surface of the engagement recess portion (the header main contact portion)  84  which is formed in the sidewall portion  81   a  into a substantially V-shaped planar view. The outer surface F 1  of the socket main contact portion  37  has a substantially trapezoidal shape with the width (the length in the longitudinal direction Y) narrowing toward the top (the outer surface F 2 ) in a planar view. The inner surface (the outer surface F 2 ) of the V-shaped engagement recess portion (the header main contact portion)  84  is in contact at two places with the outer surface F 1  of the socket main contact portion  37 , which is formed in a substantially trapezoidal shape. 
     Each socket main contact portion  37  is, therefore, in contact with the corresponding engagement recess portion (the header main contact portion)  84  at least two places in this embodiment. 
     Moreover, as described above, each socket terminal  30  and the corresponding header terminal  80 , respectively, include at least one socket contact portion (the outer surface F 3  of the sidewall portion  31   a ) and at least one header contact portion (the outer surface F 4  of the sidewall portion  81   a ) which are in contact at a region other than the socket main contact portion  37  and engagement recess portion (header main contact portion)  84 . 
     Furthermore, in the embodiment, the header housing  100  includes protrusion portions (abutment portions)  103  which are individually formed between the header connection terminal portions  83  and engagement recess portions (header main contact portions)  84  and are configured to abut on the socket housing  50  when the socket housing  50  is fitted to the header housing  100 . 
     In the embodiment, the protrusion portions (the abutment portions)  103  each having a substantially cuboid shape extending in the longitudinal direction Y are formed on both sides of the U-shaped portions  81  in the width direction X. A lower surface  103   a  of each protrusion portion (abutment portion)  103  abuts on upper surfaces  51   d  of the protrusion portions  51   c  formed in respective regions where the recess portions  51   b  are formed in the circumferential wall portion  51  of the socket housing  50  when the socket housing  50  is fitted to the header housing  100 . 
     The protrusion portions  51   c  are formed on both sides in the width direction X in a zigzag manner in the longitudinal direction Y in planar view. Accordingly, when the socket housing  50  is fitted to the header housing  100 , the protrusion portions (the abutment portions)  103  formed on both sides of the U-shaped portions  81  in the width direction X are partially supported by the protrusion portions  51   c  formed in a zigzag manner. 
     The socket terminal  30  and header terminal  80  in the embodiment are provided with lock mechanisms  120  which are, respectively, engaged with the header and socket terminals  80  and  30  to keep the connection of the socket  20  and header  70 . 
     To be specific, a first step portion (a header lock portion)  121  is formed in the outer surface (the surface on the side of the header terminal opposite to the side where the header contact portion is formed in the width direction of the header housing) F 4  of each header terminal  80 . On the other hand, a second step portion (a socket lock portion)  122  is formed in the outer surface (the surface on the side of the socket terminal opposite to the side where the socket main contact portion is formed in the width direction of the socket housing) F 3  of each socket terminal  30 . The first step portion (the header lock portion)  121  and the second step portion (the socket lock portion)  122  constitute one of the lock mechanisms  120 . In other words, the first step portion (the header lock portion)  121  and the second step portion (the socket lock portion)  122  are engaged with each other to keep the connection of the socket  20  and the header  70 . 
     In the embodiment, the first step portion  121 , which includes an inclined step surface  121   a , is formed by making thin a part of the header terminal  80  corresponding to the substantially central portion (in the vertical direction) of the surface of contact with the socket terminal  30  in the outer surface F 4 . On the other hand, the second step portion  122 , which includes an inclined step surface  122   a , is formed by making thin a part of the socket terminal  30  below the surface of contact with the header terminal  80  in the outer surface F 3 . 
     The engagement of the socket main contact portion  37  with the engagement recess portion (the header main contact portion)  84  also functions as a lock mechanism. 
     In the process of fitting the header  70  to the socket  20 , the outer surfaces F 2  and F 4  of each header terminal  80  are inserted as pushing apart the outer surfaces F 1  and F 3  of the corresponding socket terminal  30  against the elastic force. The first step portion  121  then gets over the second step portion  122 , and the socket main contact portion  37  of the socket terminal  30  is engaged with the engagement recess portion (the header main contact portion)  84 , so that the header  70  is fitted and attached to the socket  20 . In this process, the step surfaces  121   a  of the first step portions  121  are engaged with the step surfaces  122   a  of the second step portions  122  while the socket main contact portions  37  are engaged with the respective engagement recess portions (the header main contact portions)  84 . The socket  20  and header  70  are, therefore, locked with each other to keep the connection therebetween. 
     On the other hand, in the process of detaching the socket  20  from the header  70 , the socket  20  and header  70  are pulled off each other in the detachment direction. The step surface  121   a  of each first step portion  121  and the step surface  122   a  of the corresponding second step portion  122  then slide relatively to each other as pushing apart the outer surfaces of the socket terminal  30 . The first and the second step portions  121  and  122  are thus disengaged from each other. In this process, the engagement recess portion (the header main contact portion)  84  is also disengaged from the socket main contact portion  37 , thus allowing the socket  20  and header  70  to be separated from each other. 
     The engagement recess portions (the header main contact portions)  84  and the first step portions  121  are also alternately formed in the longitudinal direction Y on each side of the wall portion (the header fitting portion)  102  in the width direction. 
     In this embodiment, the plural header terminals  80  have the same shape and are mounted from an end to the other end on the header housing  100  (the header fitting body  90 ) in the longitudinal direction (the direction Y) so as to be alternately reversed. Accordingly, the header terminal  80  adjacent to the header terminal  80  illustrated in  FIG. 11  has such a shape as reversed so that the engagement recess portion (the header main contact portion)  84  is located on the left side and the first step portion  121  is located on the right side. The header terminal  80  is line-symmetric with respect to the axis which extends in the vertical direction (the direction Z) through the center in the width direction (the direction X) other than the engagement recess portion (the header main contact portion)  84  and the first step portion  121 . Accordingly, similarly in the header terminal  80  adjacent to the header terminal  80  illustrated in  FIG. 11 , the header connection terminal portions  83  and  83  protrude from both sides in the width direction X. The plural header terminals  80  are provided for the header housing  100  so that the centers of the U-shaped portions  81  in the width direction (the direction X) may be aligned on the same line in the longitudinal direction (the direction Y) (see  FIG. 10A ). 
     In the embodiment, as described above, the socket holding brackets  60  are provided at both ends of the socket housing  50  in the longitudinal direction Y, and the header holding brackets  110  are provided at both ends of the header housing  100  in the longitudinal direction Y. The socket and header holding brackets  60  and  110  are used to increase the strength of the socket and header housings  50  and  100  and to attach and fix the socket and header housings  50  and  100  to the aforementioned circuit boards. 
     In the embodiment, the fixed terminals  64  of the socket holding brackets  60  are soldered to the first circuit board  130 . This allows the socket  20  to be firmly connected to the first circuit board  130  in cooperation with the socket connection terminal portions  39  of the socket terminals  30  soldered to the first circuit board  130 . 
     Moreover, the fixed terminals  111  of the header holding brackets  110  are soldered to the second circuit board  140 . This allows the header  70  to be firmly connected to the second circuit board  140  in cooperation with the header connection terminal portions  83  of the header terminals  80  soldered to the second circuit board  140 . 
     With such a configuration, the socket  20  and header  70  which are firmly connected to the respective circuit boards can be fitted to each other to bring the socket terminals  30  into contact and conduction with the respective header terminals  80 . The conductor patterns of the circuit boards can be, therefore, electrically connected. Moreover, the socket terminals  30  and header terminals  80  are provided with the lock mechanisms  120  as described above. It is, therefore, possible to firmly keep the connection between the socket  20  and header  70 . 
     Each socket holding bracket  60  can be formed by bending a holding bracket plate  60 A which is formed by pressing a metallic plate with a predetermined thickness. The socket holding bracket  60  includes: a side plate portion  61  extending in the width direction X of the connector  10 ; and a bottom plate portion  63  which extends from the lower central part of the side plate portion  61  at a substantially right angle toward the center in the longitudinal direction Y. Both end portions of the bottom plate portion  63  are protruded outward from both sides of the connector  10  in the width direction X to form first fixed terminals  64   a.    
     At both ends of the side plate portion  61  in the width direction X, extension portions  62  are formed. The extension portions  62  include both end portions of the side plate portion  61  bent at a substantially right angle toward the center of the connector  10  in the longitudinal direction Y. An extremity portion  62   a  of each extension portion  62  in the direction of extension includes a second fixed terminal  64   b  which is extended downward and is soldered to the first circuit board  130 . 
     In the embodiment, four pairs in total of the first and second fixed terminals  64   a  and  64   b  located close to each other are provided at both ends (in the longitudinal direction Y) of the pair of long sides of the connector  10  so as to be arranged beside the corresponding socket terminals  30 . 
     As described above, in the embodiment, each socket holding bracket (each holding bracket)  60  includes the first fixed terminals  64   a  fixed to the first circuit board (the circuit board)  130  and the second fixed terminals  64   b  which are formed separately from the first fixed terminals  64   a  and are fixed to the first circuit board (the circuit board)  130 . The second fixed terminals  64   b  are extended from the side plate portion  61  of the socket holding bracket (holding bracket)  60 . 
     Herein, each second fixed terminal  64   b  is provided at a position where the distance (the distance along an outer wall surface  60   a  of the socket holding bracket  60 ; the distance along the surface of the holding bracket) from the corresponding first fixed terminal  64   a  on the socket holding bracket (holding bracket)  60  is maximized. 
     To be specific, the second fixed terminal  64   b  paired with each first fixed terminal  64   a  is formed at a position where the distance from the first fixed terminal  64   b  (the unfolded distance in the holding bracket plate  60 A; the length of an arrow a of  FIG. 7 ) is maximized when the socket holding bracket (the holding bracket)  60  is unfolded like a holding bracket plate  60 A illustrated in  FIG. 7 . 
     In the embodiment, the socket holding brackets (the holding bracket)  60  are attached to (provided for) the socket housing (the housing)  50  by insert molding. Herein, at least a part of each socket holding bracket (holding bracket)  60  is exposed along the socket housing (the housing)  50 . 
     In the embodiment, a part of an outer wall surface  54  of the circumferential wall portion  51  and plate-shaped wall portion  56  and apart of an outer wall surface  60   a  of the socket holding bracket  60  form a substantially same plane. In other words, the socket holding brackets  60  are integrally molded with the socket housing  50  so that a part of the outer wall surface  60   a  of each socket holding bracket  60  may be exposed at the substantially same plane as the outer wall surface  54  of the circumferential wall portion  51 . 
     To be specific, upper part of the outside surface  61   a  of the side plate portion  61  is exposed in a state of being flush with the upper part of the outer surface (the end face in the longitudinal direction)  54   a  extending at the outermost end of the socket housing  50  in the direction Y (the longitudinal direction). An outside surface  62   b  of each extension portion  62  is exposed in a state of being flush with the outer surface (the end surface in the short-side direction)  54   b  extending at the outermost end in the direction X (the width direction; the short-side direction). An outside surface  63   b  of the bottom plate portion  63  is exposed on a different plane from the bottom surface  56   a  (the outer wall surface  54 ) of the socket housing  50  but can be exposed in a state of being flush with the bottom surface  56   a  (the outer wall surface  54 ) of the socket housing  50 . Moreover, the outer wall surface  60   a  of each socket holding bracket  60  does not need to be exposed on the outer wall surface  54  of the circumferential wall portion  51 . Even if the outer wall surface  60   a  is exposed, the outer wall surface  60   a  does not need to be exposed in a state of being flush with the outer wall surface  54  of the circumferential wall portion  51 . 
     Furthermore, the socket housing (the housing)  50  fills the part between the surface (the outer surface  61   a  of the side plate portion  61 ) of the socket holding bracket (the holding bracket)  60  exposed in the end face of the socket housing (the housing)  50  in the longitudinal direction and the respective surfaces (the outer surfaces  62   b  of the extension portions  62 ) thereof exposed at the end faces in the short-side direction. In other words, connecting wall portions  55  are formed individually between the outer surface  61   a  of the side plate portion  61  and the outer surface  62   b  of each extension portion  62  thereof. 
     On the other hand, each header holding bracket  110  includes the same parts as the header terminals  80  and is provided in the outside (both sides in the embodiment) in the longitudinal direction Y, of the region where the header terminal group  80 G is formed. Each header holding bracket  110  is positioned at the substantially same distance apart from the header terminal group  80 G as the intervals of the header terminals  80 . 
     In other words, the header terminals  80  located at both ends among the header terminals  80  arranged side by side at predetermined intervals in the longitudinal direction Y are used as the header holding brackets  110 , and the plural header terminals  80  therebetween are used as the header terminal group  80 G. 
     The header holding brackets  110  are insert-molded so that each contact portion (the U-shaped portion  81  of each header terminal  80 ) may be partially or completely embedded. In the embodiment, each header holding bracket  110  is insert-molded so that the part of the header holding bracket  110  corresponding to the flat portion  81   c  of the U-shaped portion  81  can be exposed. This can increase the strength of the header holding brackets  110 . The header holding brackets  110  may be insert-molded so that the contact portions (the U-shaped portion  81  of the header terminals  80 ) thereof can be completely embedded. 
     Moreover, in the embodiment, the header  70  is formed to be symmetric with respect to the center of the socket  70  in a planar view, and the socket  20  is formed to be symmetric with respect to the center of the socket  20  in a planar view. Herein, the fitting groove portion (the socket fitting portion)  52  is formed to be symmetric with respect to the center of the fitting groove portion (the socket fitting portion)  52  in a planar view, and the wall portion (the header fitting portion)  102  is configured to be symmetric with respect to the center of the wall portion (the header fitting portion)  102  in a planar view. Accordingly, the center of the fitting groove portion (the socket fitting portion)  52  is located at the same position as the center of the socket  20 , and the center of the wall portion (the header fitting portion)  102  is located at the same position as the center of the header  70 . 
     As described above, the connector  10  of the embodiment includes the socket  20  and header  70  which are fitted to each other. 
     When the fitting groove portion (the socket fitting portion)  52  of the socket housing  50  is fitted onto the wall portion (the header fitting portion)  102  of the header housing  100 , the socket terminals  30  and the header terminals  80  are brought into contact with each other. 
     Furthermore, the socket terminal group  30 G including the plural socket terminals  30  arranged in the longitudinal direction Y of the socket housing  50  is provided only in a single line in the socket housing  50 , and the header terminal group  80 G including the plural header terminals  80  arranged in the longitudinal direction Y of the header housing  100  is provided only in a single line in the header housing  100 . 
     By individually providing the socket terminal group  30 G and the header terminal group  80 G, which comes into contact with the socket terminal group  30 G, only in a single line in the longitudinal direction Y, the socket housing  50  and header housing  100  can be reduced in width (the width in the direction X). In other words, the width (the width in the direction X) of the connector  10  can be reduced, thus increasing the freedom of arrangement of the connector  10  on the circuit boards (the first and second circuit boards  130  and  140 ). 
     Still furthermore, in the embodiment, each socket holding bracket (each holding bracket)  60  includes: the side plate portion  61  extending in the width direction X of the connector  10 ; and the bottom plate portion  63  which is bent from the lower center of the side plate portion  61  toward the center in the longitudinal direction Y at a substantially right angle. Each socket holding bracket (each holding bracket)  60  includes: the first fixed terminals  64   a  fixed onto the first circuit board (the circuit board)  130 ; and the second fixed terminals  64   b  which are separately formed from the first fixed terminals  64   a  and are fixed onto the first circuit board (the circuit board)  130 . 
     Accordingly, it is possible to further increase the soldering strength of the socket  20  (the connector  10 ) onto the first circuit board (the circuit board)  130 . 
     Still furthermore, in the embodiment, the second fixed terminals  64   b  are extended from the side plate portions  61  of each socket holding bracket (holding bracket)  60 . 
     In other words, the socket  20  (the connector  10 ) is soldered to the first circuit board (the circuit board)  130  with the first fixed terminals  64   a  extended from the bottom plate portion  63  of each socket holding bracket (each holding bracket)  60  and the second fixed terminals  64   b  extended from the side plate portion  61 . This can further increase the soldering strength of the socket  20  (the connector  10 ) to the first circuit board (the circuit board)  130  and also increase the strength of the sidewall of the socket  20  (the connector  10 ). 
     Herein, the second fixed terminal  64   b  is provided at a position where the distance from the first fixed terminal  64   a  is maximized on the socket holding bracket (holding bracket)  60 . 
     To be specific, in the unfolded state of each socket holding bracket (each holding bracket)  60  like the holding bracket plate  60 A, the second fixed terminal  64   b  paired with each first fixed terminal  64   a  is formed at a position where the distance from the first fixed terminal  64   a  is maximized (the unfolded distance on the holding bracket plate  60 A). 
     Accordingly, the movement of each socket holding bracket (each holding bracket)  60  is restricted by the first and second fixed terminals  64   a  and  64   b . This can further increase the strength of the socket holding brackets (the holding brackets)  60  and also increase the strength of the socket  20  (the connector  10 ). 
     Still furthermore, in the embodiment, the socket holding brackets (the holding brackets)  60  are attached to (provided for) the socket housing (the housing)  50  by insert molding. This can increase the molded wall thickness of the socket housing (the housing)  50  and increase the strength of the socket housing (the housing)  50 . 
     Herein, at least a part of each socket holding bracket (each holding bracket)  60  is exposed along the socket housing (the housing)  50 . To be specific, each socket holding bracket (each holding bracket)  60  is exposed at four sides, i.e., the bottom surface  56   a  and side surfaces  54   a ,  54   b , and  54   b  on three sides in the socket housing (housing)  50 . This can further increase the strength of the sidewall of the socket  20  (connector  10 ). 
     Still furthermore, in the embodiment, the socket housing  50  fills the part between the surface (the outside surface  61   a  of the side plate portion  61 ) of each socket holding bracket (each holding bracket)  60  which is exposed on the end face of the socket housing (the housing)  50  in the longitudinal direction and the surfaces (the outside surfaces  62   b  of the extension portions  62   b ) which are exposed in the end faces thereof in the short-side direction. This can prevent the socket holding brackets (the holding brackets)  60  from falling off the socket housing (the housing)  50 . 
     Still furthermore, in the embodiment, each socket terminal  30  and the header terminal  80  corresponding thereto, respectively, include the socket and header main contact portions at least one of which is elastically deformable and which are brought into contact with each other. 
     The socket terminal group  30 G is formed by arranging the plural socket terminals  30  in such a manner that the socket terminals  30  with the socket main contact portions  37  located on one side in the width direction X of the socket housing  50  and the socket terminals  30  with the socket main contact portions  37  located on the other side are alternately provided. 
     The aforementioned configuration of the socket terminal group  30 G can prevent the socket main contact portions  37  from being located on one side in the width direction X or in the longitudinal direction Y when the socket  20  and header  70  are fitted to each other. Accordingly, the socket  20  and header  70  can be fitted in a balanced manner, or the socket main contact portions  37  and engagement recess portions (the header main contact portions)  84  can be brought into contact with each other in a balanced manner. This can further enhance the fitting retention of the socket  20  and header  70 . 
     In the embodiment, especially, in the width direction X of the socket housing  50 , the second step portions (the socket lock portions)  122 , which are engaged with the first step portions (the header lock portions)  121 , are formed on the side of the socket terminals  30  opposite to the region where the socket main contact portions  37  are formed. The socket main contact portions  37  and the second step portions (the socket lock portions)  122  are, therefore, alternately arranged in the longitudinal direction Y, so that the socket  20  and header  70  can be fitted to each other in a more balanced manner. 
     Still furthermore, in the embodiment, the fitting groove portion (the socket fitting portion)  52  of the socket housing  50  includes the socket wide portions  52   b , which are wider than the region (the socket terminal group housing portion  52   a ) where the socket terminal group  30 G is formed, in the outside (in the regions corresponding to the header wide portions  102   b ) in the longitudinal direction Y, of the region (the socket terminal group housing portion  52   a ) where the socket terminal group  30 G is formed. 
     On the other hand, the wall portion (the header fitting portion)  102  of the header housing  100  includes the header wide portions  102   b , which are wider than the region (the header terminal group housing portion  102   a ) where the header terminal group  80 G is formed, in the outside in the longitudinal direction Y, of the region (the header terminal group housing portion  102   a ) where the header terminal group  80 G is formed. 
     By providing the wide fitting portions in the outside in the longitudinal direction Y, of the region where the terminals are formed as described above, the header  70  can be prevented from being fitted in the incorrect position of the socket  20  deviated in the longitudinal direction Y. 
     In the embodiment, especially, the wall portion (the header fitting portion)  102  and the fitting groove portion (the socket fitting portion)  52  each have a substantially I-shaped planar view. This can more reliably prevent the socket  20  from being fitted to the incorrect position of the header  70 . 
     Still furthermore, the header  70  is formed so as to be symmetric with respect to the center of the header  70  in a planar view. Accordingly, the header  70  rotated by 180 degrees can be fitted to the socket  20 , thus improving the workability in assembling the header  70 . 
     Still furthermore, in the embodiment, each socket terminal  30  and the header terminal  80  corresponding thereto, respectively, include at least one socket contact portion (the outer surface F 3  of the sidewall portion  31   a ) and at least one header contact portion (the outer surface F 4  of the sidewall portion  81   a ) which come into contact with each other at the places other than the socket main contact portion  37  and engagement recess portion (the header main contact portion)  84 . This can increase the reliability in contact between the socket main contact portion  37  and engagement recess portion (the header main contact portion)  84 , thus further enhancing the fitting retention of the socket  20  and header  70 . 
     Still furthermore, in the embodiment, each socket main contact portion  37  and the engagement recess portion (the header main contact portion)  84  corresponding thereto are configured to come into contact with each other at at least two places. This further increases the reliability of contact between the socket main contact portion  37  and engagement recess portion (the header main contact portion)  84 . 
     Still furthermore, in the embodiment, the socket terminal  30 G is configured so that the socket terminals  30  with the socket connection terminal portions  39  protruding to one side of the socket housing  50  in the width direction X and the socket terminals  30  with the socket connection terminal portions protruding to the other side are alternately located. Accordingly, the socket connection terminal portions  39  alternately protrude on one side and on the other side in the width direction X. This prevents the positions of attachment of the socket connection terminals  39  to the first circuit board  130  from being located on one side in the width direction X or on one side in the longitudinal direction Y. Accordingly, the position of attachment of the socket  20  to the first circuit board  130  is well balanced, thus preventing the socket  20  from turning in the process of soldering. Moreover, it is possible to prevent the socket  20  from standing up due to the tombstone effect. 
     Still furthermore, in the embodiment, each header terminal  80  includes the U-shaped portion  81  which is provided with both sidewall portions  81   a ,  81   a  and the connecting portion  81   b  and is formed in an inverted U-shape. Accordingly, the shape of each header terminal  80  is substantially symmetric in the horizontal direction, so that the balance of the shape of the header  70  can be improved. 
     Still furthermore, the flat portion  81   c  is formed in the outer side of the connecting portion  81   b . The flat portion  81   c  can be easily sucked by a machine such as a robot arm, and the header  70  can be, therefore, easily picked up by a machine or the like in the process of soldering the header  70  to the second circuit board  140  and in other processes. This can increase the soldering workability of the header  70  onto the second circuit board  140 . 
     Still furthermore, in the embodiment, the header terminal group  80 G includes the header terminals  80  with the header connection terminal portions  83  protruding toward one side of the header housing  100  in the width direction and the header terminals  80  with the header connection terminal portions  83  protruding toward the other side. To be specific, the header connection terminal portions  83 ,  83 , respectively, protrude from both sides of the header terminals  80  in the width direction X of the header housing  100 . This prevents the positions of attachment of the header connection terminals  83  on the second circuit board  140  from being located on one side in the width direction X or on one side in the longitudinal direction Y, thus improving the balance of the position of attachment of the header  70  to the second circuit board  140  and preventing the header  70  from turning in the soldering process. Moreover, it is possible to prevent the header  70  from standing up due to the tombstone effect. Furthermore, it is possible to further increase the soldering strength of the header  70  onto the second circuit board  140  and increase the current capacity. 
     Still furthermore, in the embodiment, each header holding bracket  110  includes the same parts as the header terminals  80  and is located at the substantially same distance as the intervals of the header terminals  80  from the header terminal group  80 G in the outside in the longitudinal direction Y (on both sides in the embodiment), of the region where the header terminal group  80 G is formed. Accordingly, the parts can be shared, and the cost can be reduced. Moreover, the header  70  can be more easily manufactured. 
     Still furthermore, in the embodiment, the header housing  100  includes the protrusion portions (the abutment portions)  103  which are formed between the header connection terminal portions  83  and the engagement recess portions (the header main contact portions)  84  and abut on the socket housing  50  when the socket housing  50  and header housing  100  are fitted to each other. This can prevent the socket  20  and header  70  fitted to each other from wobbling. 
     As described above, according to the embodiment, it is possible to provide the connector  10 , which can improve in strength of fixation on the circuit board  130 , and the socket  20  and header  70  included in the connector  10 . 
     Hereinabove, the preferred embodiment of the present invention is described. However, the present invention is not limited to the aforementioned embodiment and can be variously modified. 
     For example, the specifications (the shapes, sizes, layouts, and the like) of the socket terminals, header terminals, and the other components can be properly changed.