Abstract:
A substrate connector utilizes a plurality of conductive terminals, each of which are held in a single terminal-receiving cavity of a substrate. The terminals of the connector have a hook-shape with a retention portions in the form of a fork having a central slot and two free ends spaced apart from the retention portion and which protrude out of their cavities for contacting contact pads on opposing circuit boards. The retention portions engage abutments formed in the cavities to hold the terminals in place but do so in a manner that permits the terminals to move in both the vertical and horizontal directions.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates generally to a substrate connector, and more particularly to substrate connector with improved contact force characteristics. 
     Conventional flat connectors that use a large number of terminals are used to connect a semiconductor device to a circuit board or to connect two substrates with each other. An example is shown in Japanese Patent Application Laid-Open (Kokai) No. 08-222335).  FIG. 13  is a cross-sectional view of a conventional connector. 
     In  FIG. 13 ,  801  represents a connector housing that has an upper housing  803  with an opening  804  and a lower housing  805  with a bore  806 .  810  is a connector terminal provided with a base  811  mounted in the bore  806 , a contact arm  813  that is bent from the base  811  and extending upward, and a contact part  812  protruding downward from the lower end of the base portion  811 . When the terminal  810  is inserted into the bore  806  from above, the lower end of a wing  815  protrudes sideways from the terminal  810  and abuts against the bottom surface  808  of a groove  807  in the side of the bore  806  which limits the downward movement of the terminal  810 . A portion of the upper surface of the bore  806  is covered by the upper housing  803  in order to restrict upward movement of the terminal  810 . Hence, the terminal  810  is prevented from coming loose from the bore  806  and is firmly held by the housing  801 . 
     Further, the terminal contact part  812  protrudes downwardly more than the bottom surface of the lower housing  805  and comes into contact with a conductive pad  821  formed on the upper surface of the substrate  820 . A solder ball  831  formed on the lower surface of the semiconductor device  830  is kept in contact with a tip end part  814  of the contact piece  813  of the terminal  810 . This provides electrical continuity between the conductive pad  821  and the solder ball  831  via the terminal  810 . 
     In this type of connector the up and down movement of the terminal  810  is restricted, and when the spacing between the bottom surface of the lower housing  805  and the upper surface of the substrate  820  changes, this spacing change can only be absorbed within a range of plastic deformation permitted for the contact part  812  and the tip end part  814  of the terminal  801 . When a change occurs that exceeds the range of elastic deformation, the terminal  810  is not permitted to smoothly move up and down and no longer keeps contact with the conductive pad  821 . The semiconductor device  830  or the substrate  820  may include more and more terminals and become larger in its size and therefore, a variation in the vertical position of the solder ball  831  (or conductive pad  821 ) may increase, thereby preventing secure contact. In addition, vertical forces exerted by the semiconductor device  830  or the substrate  820  cannot be absorbed by the terminal  810 , and the terminal  810  may buckle eventually, resulting in its breakage. It then becomes unable to stabilize the force, whereby the contact point  812  and the tip end part  814  contact the conductive pad  821  and the solder ball  831 , respectively, which fails to keep secure connection. Additionally, because the upper and lower housings  803 , 805  are joined together to form the housing  801 , the assembly process becomes complicated, resulting in an increase in cost. Furthermore, the terminal  810  cannot be removed from the housing  801 , and thus the damaged terminal  810  cannot be replaced with a new terminal. 
     SUMMARY OF THE INVENTION 
     An object of the present invention therefore is to solve the above-mentioned problems encountered by the conventional substrate connector through provision of a reliable substrate connector in which a concave part provided in the terminal and is engaged with a convex part received in a terminal-receiving cavity formed so as to penetrate a plate-like housing, so that the terminal is held in the cavity and is permitted to vertically and laterally move therein, thereby absorbing variations in the space defined between the connector and the substrate while maintaining a reliable electric contact with the substrate, reducing the cost through a simplified structure, and permitting easy replacement of a terminal. 
     In order to achieve the above object, the present invention provides a substrate connector, which includes an insulative housing, and terminals mounted to the housing, in which one surface of the housing is opposed to a first substrate where first contact pads are arranged, and in which the other surface of the housing is opposed to a second substrate where second contact pads are arranged, and where the terminal provides a connection between the first contact pads of the first substrate and the second contact pads of the second substrate, and wherein the housing has cavities that accommodate the terminals, wherein each terminal is provided with a bifurcated mounting portion bifurcated. The terminal has a concave portion, or recess, formed in an outer edge thereof, and wherein the terminal-receiving cavity includes a convex part inwardly protruding from an inside surface thereof that engages with the concave portion to hold the terminal so that the terminal moves in the direction of thickness of the housing and in the width direction of the mounting portion. 
     In accordance with another embodiment of the present invention, there is provided a substrate connector, wherein the terminal includes: a first bending portion connected to an end of the mounting portion located adjacent to the first substrate; a body portion with an end located adjacent to the first substrate and connected to the first bending portion; a tilting portion connected to an end of the body portion that is adjacent to the second substrate and tilts in a direction opposite to a bending direction of the first bending portion; and, a second bending portion connected to an end of the tilting portion located close to the second substrate and bending in a direction opposite to the bending direction of the first bending portion. 
     In accordance with a further embodiment of the present invention, a substrate connector has a terminal that contacts the first contact pad at the first bending portion and with the second contact pad at the second bending portion thereof, while being elastically deformable so as to absorb variations in the distance between the first and second contact pads. 
     In accordance with a still further embodiment of the present invention, in the substrate connector, at least a portion of the first bending portion protrudes from one surface of the housing even when the terminal is positioned closest to the second substrate, and wherein at least a portion of the second bending portion protrudes from the other surface of the housing even when the terminal is positioned closest to the first substrate. 
     In accordance with a further embodiment of the present invention, there is provided a substrate connector, with a mounting portion having an upper convex portion and a lower convex portion protruding outward from an outer edge thereof to define the concave portion, and wherein a lower side of the lower convex portion closer to the first substrate contacts a convex part while inserted into the broad width part thus causing the bifurcated portion of the terminal to be elastically deformed and inwardly tilted. 
     In accordance with the present invention, a terminal is provided for use with a substrate connector in the context of a plate-shaped housing having one surface thereof opposed to a surface of a first substrate supporting first contact pads and the other surface is opposed to a surface of a second substrate supporting second contact pads; and, a terminal-receiving cavity is formed in the housing. The terminal is provided with a bifurcated mounting portion with two arms and each arm is formed with a concave portion thereof on an outer edge thereof, wherein the cavity is provided, with a broad width portion that is wider than the mounting portion and, wherein the mounting portion is accommodated in the broad width portion of the cavity and the terminal concave portion engages a convex part, or lug, protruding inward from an inside surface of the broad width portion of the cavity so that the terminal moves vertically and horizontally in the housing. 
     According to the present invention, the concave portion formed in the terminal engages the convex part formed in the housing cavity thereby permitting the terminal to be held so that it moves vertically and laterally in the cavity. Hence, variations in space between the substrate connector and a substrate are appropriately absorbed while maintaining contact with the substrate, reducing costs through a simplified structure, and allowing replacement of the terminal as required thereby enhancing the reliability. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view showing a connector incorporating a first embodiment of the present invention; 
         FIG. 2  is an enlarged view of important sections of the connector of  FIG. 1 ; 
         FIG. 3  is a perspective view of  FIG. 2  showing the state where the connector is connected to a first substrate; 
         FIG. 4  is a perspective view of the connector of  FIG. 3  showing the connector connected to both a first and second substrate; 
         FIG. 5  is an exploded view of the assembly of  FIG. 4 ; 
         FIG. 6  is a perspective view showing a terminal used in the connector of  FIG. 1 ; 
         FIG. 7  is a first cross-sectional view of the connector of  FIG. 1 , showing a terminal accommodated in a terminal-receiving cavity thereof; 
         FIG. 8  is a perspective view, partly in cross-section, showing a housing of the assembly of  FIG. 1 ; 
         FIGS. 9   a - 9   c  are second cross-sectional views showing the terminal accommodated in the cavities, in which (a) the terminal is in the lowest position in the housing, (b) an intermediate state in the housing, and (c) the terminal is in the highest position in the housing; 
         FIGS. 10   a - 10   c  are third cross-sectional views taken from an end, showing the terminal in the terminal-receiving cavities, in which (a) the terminal is in the lowest position in the housing, (b) an intermediate state in the housing, and (c) the terminal is in the highest position in the housing; 
         FIG. 11  is a cross-sectional view showing the connector of the present invention to a first and second substrate; 
         FIG. 12  is a perspective view showing a terminal according to a second embodiment of the present invention; and 
         FIG. 13  is a cross-sectional view of a conventional connector. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to the drawings,  1  represents a connector used as a substrate connector. The connector  1  has a rectangular housing  11 . The housing  11  is used between a first substrate  111  and a second substrate  121  in such manner that one surface thereof is opposed to a surface of the first substrate  111  ( FIG. 3 ) on which first contact pads  113  are arranged and the other surface thereof is opposed to a surface of the second substrate  121  on which second contact pads  123  are arranged. ( FIG. 4 .) Thus, the housing  11  provides continuity between the first contact pads  113  of the first substrate  111  and the second contact pads  123  of the second substrate  121 . 
     The first substrate  111  and the second substrate  121  are, for example, circuit boards such as printed circuit boards used in various types of electronic devices. The first substrate  111  or the second substrate  121  may also include a semiconductor device such as an IC or LSI , or any type of electronic device as long as it includes contact pads (or electrodes) on one surface. In the drawings, the first substrate  111  and the second substrate  121  are circuit boards that include planar first contact pads  113  and second contact pads  123 . The shape of the first and second contact pads  113 , 123  may take any shape such as a pad, a solder ball or a cube and in the embodiment in question the shape takes a pad having a flat surface. 
     The housing  11  is integrally formed of an insulating material and includes a plurality of terminal-receiving cavities  12 , which penetrate the housing  11  in a direction of thickness thereof, that is, they preferably extend through the front and rear surfaces. In the example shown, the cavities  12  are arranged only in a partial area of the housing  11 , but may be arranged in any arbitrary area as required and may be densely arranged over the entire surface area of the housing  11 . 
     The cavities  12  each receive terminals  51  made of a conductive material. A portion of each terminal  51  protrudes from the front and rear surfaces of the housing  11 . In the example shown, while the terminals  51  are accommodated only in some of the cavities  12 , and they may be accommodated in an arbitrary number of cavities, for example, in all such cavities. 
     The cavities  12  and the terminals  51  are arranged so as to be in registration with the layouts of the first contact pads  113  on the first substrate  111  and the second contact pads  123  on the second substrate  121 . In the drawings, the cavities  12  and the connection terminals  51  are arranged to form diagonal arrays at an angle of 45 degrees with respect to the side of the housing  11  and are arranged in a zigzag (or staggered) pattern. With this arrangement, it is possible to arrange a large number of terminals  51  within a certain area and densely arrange the terminals  51  at a small pitch. For example, in case the surface area of the housing  11  is around 1600 mm 2 , it is possible to arrange about 1600 terminals  51  in a lattice-like pattern. 
     The housing  11  has a plurality of mounting holes  17  and each mounting hole  17  fastening member  131  for mounting the housing  11  between the first substrate  111  and the second substrate  121  is inserted. On the surface of the housing  11  opposed to the second substrate  121  are formed annular protrusions  17   a  surrounding the corresponding mounting holes  17 , which are formed in the four corners, respectively. The annular protrusion  17   a  is formed to protrude from the surface of the housing  11  toward the second substrate  121 . The upper end surface of the annular protrusion  17   a  abuts against the second substrate  121  and serves as a spacer for keeping a desired spacing between the housing  11  and the second substrate  121  in order to avoid over-tightening the fastening members  131 . The annular protrusions  17   a  may be formed so as to surround the mounting holes  17  other than those in the four corners. 
     A plurality of first guide columns  16  protrude from the lower surface of the housing  11  toward the first substrate  111 . A plurality of second guide columns  18  protrude from the upper surface of the housing  11  toward the second substrate  121 . The first guide columns  16  and the second guide columns  18  have their tips engaged in respective first guide holes  114  formed in the first substrate  111  and second guide holes  124  formed in the second substrate  121 , and serve to position the housing  11  with respect to the first and second substrate  111 , 121 . This positioning allows each of the terminals  51  mounted on the housing  11  to be in registration with each first contact pads  113  of the first substrate  111  and each second contact pads  123  of the second substrate  121 . First and second guide columns  16   a , 18   a  are formed in two groups of positions, one group where the columns are formed in mutually the same positions via the housing  11  and in the other group where the columns are formed in non-mutually different positions via the housing  11 . Depending on the difference between theses positions, the guide columns can serve as polarizing keys indicating the correct connecting directions of the connector  1 . 
     As shown in  FIG. 5 , four first guide columns  16  and four second guide columns  18  are formed. Three pairs of first guide columns  16   a  and second guide columns  18   a  are formed the same position and a single pair of first and second guide column  16   b , 18   b  are formed in non-relatively different positions. 
     The first substrate  111  and the second substrate  121  each have a plurality of first mounting holes  112  and second mounting holes  122 , which extend through the respective substrates  111  and  121 . With the connector housing  11  pinched from both sides by the first and second substrate  111 , 121 , the first and second guide columns  16 , 18  are engaged and fit into the first and second guide holes  114 , 124 . Each mounting hole  17  of the housing  11 , each first mounting hole  112  and each second mounting hole  122  are brought into alignment with one another. It is thus possible to insert a fastening member  131  through the aligned mounting hole  17 , first mounting holes  112  and second mounting holes  122 . Therefore, by screwing a nut  132  onto the fastening member  131 , the first substrate  111  and the second substrate  121  are fastened together with the housing  11  pinched from both sides. 
     This allows the first and second substrates  111 , 121  to be connected via the connector  1  pinched therebetween. In  FIG. 4 , the connector  1  is disposed beneath and hidden by the second substrate  121  and is thus not seen. 
     As best shown in  FIG. 6 , the terminal  51  is constituted by a single member formed integrally by bending a long metal member, and has a substantial shape of a scoop or a hook. The terminal  51  includes a body portion  52  extending vertically, a first bending portion  53  connected to the bottom end of the body portion  52  and bent at an angle of almost 180 degrees, a vertical mounting portion  54  connected to the end of the first bending portion  53  (opposite to the body portion  52 ), a tilting portion  57  connected to the top end of the body portion  52  and tilting in a direction opposite to the bending direction of the first bending portion  53 , and a second bending portion  58  connected to the top end of the tilting portion  57 , with a free end oriented downward and bent in a direction opposite to the bending direction of the first bending portion  53 . The first bending portion  53  functions as a first terminal contact that comes into contact with the first contact pad  113  of the first substrate  111  while the second bending portion  58  functions as a second terminal contact that comes into contact with the second contact pad  123  of the second substrate  121 . The first and second terminal contacts have curved surfaces and, as shown in the drawings, the curved surfaces face in opposite directions. 
     The mounting portion  54  is bifurcated and is formed by a slot  54   a  extending vertically so that the terminal has the shape of a tuning fork. The mounting portion  54  therefore has two free arms and each arm has an upper and lower convex portion  55   a , 55   b  that are shown as projections, stubs or lugs. These projections  55   a , 55   b  define a concave portion, or recess,  56  between them. The upper convex portion  55   a  and the lower convex portion  55   b  will be referred to generally as a terminal convex portion  55 . 
     The width of the cavity mounting portion  54  is larger than that of the terminal body portion  52 , the first bending portion  53 , the tilting portion  57  and the second bending portion  58 . The lower side surface of the lower convex portion  55   b  is a tapered surface  54   b  gradually narrows in its width toward the lowermost end. By using the tapered surface  54   b , it is possible to readily insert the terminal  51  into the housing cavities  12 . 
     As shown in  FIG. 8 , each cavity  12  includes a tilted surface  13  formed in a portion close to a front surface close to the housing surface that opposes the second substrate  121 . The tilted surface  13  tilts so as to correspond to the tilting portion  57  of the terminal  51  and, as shown in  FIGS. 7 and 9 , is opposed to the tilting portion  57  of the connection terminal  51  accommodated in the cavity  12 . As best shown in  FIG. 10 , the cavity  12  includes a broad width part  14  and a narrow part  19  extending vertically in the housing  11 , with the width of the narrow part  19  formed narrower than that of the broad width part  14 . The broad width part  14  is formed in an area corresponding to the mounting portion  54  of the terminal  51  and has a width larger than that of the mounting portion  54  so as to accommodate the mounting portion  54 . The narrow part  19  has a width larger than that of the first bending portion  53  and the body portion  52  so as to accommodate the first bending portion  53  of the terminal  51  and the body portion  52 . The side wall of the narrow part  19  opposed to the body portion  52  is formed to be in continuation with the tilted surface  13  and functions as a wall that restricts the range in which the connection terminal  51  elastically deforms. 
     On the opposing inside surfaces on both sides of the broad width part  14  are formed respective convex parts, or lugs (or projections),  15 , respectively, which protrude inwardly to the cavity. These lugs  15  engage in the concave portions  56  (recesses) of the mounting portion  54  of the terminal  51  when the terminal  51  is inserted in the cavity  12  and prevent the terminal  51  from being removed from the cavity  12 . The projections are preferably four-sided in the shape of a square or rectangle as shown. The dimension of the cavity convex part  15  in the vertical direction (or length) is smaller than the vertical dimension of the terminal concave portion  56 . Thus, the terminal  51  is held to move vertically within a predetermined range in the cavity  12 . In the case of variations, or distortion or undulation of the first and second substrates are large, it is readily possible to increase a predetermined range “t” of the vertical movement of the terminal  51  by reducing the vertical dimension of the convex part  15  or increasing the vertical dimension of the concave portion  56  of the connection terminal  51 , thus changing these dimensions. Preferably, the length of the concave portion  56  (recess) is greater than the length of the cavity projections  15 . 
     As shown in  FIGS. 9(   c ) and  10 ( c ), the upper face of the broad width part  14  of the housing  11  is open. Thus, even when the terminal  51  is in the highest position in the housing  11 , it is possible to position the upper end of the upper convex portion  55   a  of the connection terminal  51  above the surface of the housing  11  or, conversely, below the surface of the housing  11 . In this way, the upper end of the upper convex portion  55   a  is not regulated by the housing  11  so that a wider predetermined range “t” may be readily set. 
     The predetermined range “t” is set based on the relation between the vertical dimension of the convex parts  15  and the vertical dimension of the concave portions  56  and is given by a value obtained by subtracting the vertical dimension of each convex part  15  from the vertical dimension of each concave portion  56 . For example, the range “t” is set to about 100 μm in this embodiment. 
     As shown in  FIGS. 9(   a ) and  10 ( a ), where the terminal  51  is in the lowest position with respect to the housing  11 , i.e., closest to the first substrate  111 , the lower end of the upper convex portion  55   a  abuts the upper end of the convex part  15 , which restricts any further downward movement of the terminal  51 . As shown in  FIGS. 9(   c ) and  10 ( c ), where the terminal  51  is in the highest position in the housing  11 , i.e., the position closest to the second substrate  121 , the upper end of the lower convex portion  55   b  abuts the lower end of the convex part  15 , which restricts any further upward movement of the terminal  51 . 
     Even where the terminal  51  is in the highest position in the housing  11 , the lower end of the first bending portion  53  is positioned below the rear surface of the housing  11 , i.e., below the surface opposed to the first substrate  111 . Where the terminal  51  is in the lowest position with respect to the housing  11 , the upper end of the second bending portion  58  is positioned above the front surface of the housing  11 , i.e., above the surface opposed to the second substrate  121 . The lower end of the first bending portion  53  is set to a position being protruded by about 50 μm from the rear surface of the housing  11 . 
     The terminal  51  is free to move vertically in the cavity  12 , and is thus held therein in a floating state. In case the spacing between the housing  11  and the first substrate  111  or the second substrate  121  is not constant when the first substrate  111  and the second substrate  121  are connected with the connector  1  therebetween, the first bending portion  53  of the terminal  51  and the second bending portion  58  can maintain contact with the corresponding first contact pad  113  and second contact pad  123 . It is possible to electrically connect the first and second substrate  111 , 121  even in case the housing  11 , the first substrate  111  or the second substrate  121  is subjected to distortion or warpage. 
     When the first substrate  111  and the second substrate  121  are fastened together with the housing  11  pinched therebetween, each of the connection terminals  51  is elastically deformed due to the spring property thereof. In this case, the first and second bending portion  53 , 58  are brought into contact with the first and second contact pads  113 , 123  and are pressed from above and below. The body portion  52 , the first bending portion  53 , the tilting portion  57  and the second bending portion  58  are thereby elastically deformed. In addition, as best shown in  FIG. 11 , the tilting portion  57  is further inclined and the second bending portion  58  is deformed so as to approach the surface of the housing  11 . 
     Because the housing cavities  12  have at their portion adjacent to the surface thereof, the tilting surface  13  formed thereon, the body portion  52  or the tilting portion  57  does not interfere with the end of the cavity  12  close to the surface but, rather is flexibly deformed. The tilting portion  57  tilts in a direction opposite to the bending direction of the first bending portion  53  and moves away from the mounting portion  54  toward the tip end. In other words, the tilting portion  57  forms an acute angle with respect to the surface of the housing  11  and has a gradually widening shape. Thus, the terminal body portion  52  or tilting portion  57  are more flexibly deformed. 
     When the terminal  51  deforms, the side surface of each of the upper convex portion  55   a  and the lower convex portion  55   b  of the terminal  51  is pressed against the side surface of the cavity broad width part  14  close to the tilting surface  13 . In this state, it is possible to stabilize the position of each terminal  51  in the cavity  12 . Furthermore, the stress of deformation concentrates on the mounting portion  54  when the tilting portion  57  of the terminal  51  moves. The mounting portion  54  is engaged with the housing  11  at two sections on the side surface of the upper convex portion  55   a  and two sections on the side surface of the lower convex portion  55   b , total four sections. This prevents possible deformation of the mounting portion  54  caused by a stress thereby smoothly deforming the terminal  51 . 
     In this way, the terminal  51  is deformed elastically and flexibly. Even when the spacing between the housing  11  and the first substrate  111  or the second substrate  121  is not constant, the first bending portion  53  and the second bending portion  58  of the connection terminal  51  can keep contact with the first contact pad  113  and the second contact pad  123 . Thus, even in case the housing  11 , the first substrate  111  or the second substrate  121  is distorted or warped, it is possible to electrically connect the first substrate  111  and the second substrate  121 . The first substrate  111  and the second substrate  121  are not subject to strong counterforces from the connection terminals  51  so that they are free from damage. 
     Further, elastic force generated by elastic deformation of the terminals  51  energizes the first bending portion  53  and the second bending portion  58  toward the first contact pads  113  and the second contact pads  123 , which secures contact with the above-mentioned first and second contact pads  113  and  123 . 
     A change in the inclination of the tilting portion  57  causes the second bending portion  58  to move in a direction parallel to the housing  11  and rub against the surface of the second contact pads  123 . This generates a wiping effect that removes any foreign substance attached to the surfaces of the second bending portions  58  and the second contact pads  123  that hampers electrical conductivity. This ensures reliable electrical continuity between the second bending portions  58  and the second contact pads  123 . 
     Furthermore, the terminal  51  includes the tilting portion  57  and is thus capable of absorbing contact pressure generated in connection to the second substrate  121  in vertical direction as well as tilting direction. The terminal  51  is not buckled in vertical direction and is free from damage. 
     Between the inner side surface at either side of the broad width part  14  in the cavity  12  and the upper convex portion  55   a  or the lower convex portion  55   b  at either side of the mounting portion  54  of the terminal  51  accommodated in the cavity  12  is a small clearance that will not prevent vertical movement of the terminal  51 . Between the convex part  15  at either side of the broad width part  14  and the concave portion  56  at either side of the mounting portion  54  is also a small clearance that will not prevent vertical movement of the terminal  51 . Thus, the terminal  51  is held in the cavity  12  while being allowed to move widthwise of the mounting portion  54 , or horizontally, within the range of the clearance. The upper convex portion  55   a  and the lower convex portion  55   b  may move in opposite directions to each other to allow the terminal  51  to tilt. In this way, the terminal  51  is held in the cavity  12  in a state where not only vertical and horizontal movement and tilting are allowed. In case the housing  11 , the first substrate  111  or the second substrate  121  are distorted or warped, the connector still reliably provides electric connection between the first substrate  111  and the second substrate  121 . 
     For mounting, each terminal  51  is lowered from above with the first bending portion  53  facing downward to insert the connection terminal  51  into the cavity  12 . In this process, the lower convex portion  55   b  of the mounting portion  54  abuts the convex part  15  at either side of the broad width part  14 . The lower side surface of the lower convex portion  55   b  is a tapered surface  54   b  that becomes narrower toward the lowermost end. The portion of the mounting portion  54  bifurcated laterally is elastically deformed and tilts inward, which allows the lower convex portion  55   b  to smoothly pass through the convex parts  15  on both sides. Therefore, it is possible to readily insert the terminals  51  into the cavities  12  to accommodate the terminals  51  therein. By accommodating the terminals  51  in each cavity  12 , it is possible to obtain the substrate connector  1  of which the terminals  51  are mounted on the housing  11  as shown in  FIG. 1 . By elastically deforming, with the manual operation of an operator or use of a tool, the portion of the mounting portion  54  which is bifurcated laterally so as to be inwardly inclined, it is possible to easily remove each of the terminals  51  from the corresponding terminal-accommodating recessed part  12 . Thus, the terminals  51  may be readily removed if damaged or contaminated. Accordingly, it is possible to selectively replace a single terminal  51  with a spare in an individual manner. 
     The first substrate  111  and the second substrate  121  are connected to each other by the connector  1 , and the connector  1  is connected to the surface of the first substrate  111  on which the first contact pads  113  are arranged as shown in  FIG. 3 . In this case, the first guide columns  16   a ,  16   b  protrudes from the rear surface of the housing  11  and are fitted into the first guide hole  114  formed in the first substrate  111 . This positions the housing  11  and the first substrate  111  and causes the first bending portion  53  of each terminal  51  to contact the corresponding first contact pads  113 . In this stage, the terminals  51  are arranged in the lowest position or in a position above the lowest position in response to a variation in the vertical position of each first contact pad  113  caused by distortion or undulation of the first substrate  111 . 
     Subsequently, the connector  1  is connected to the surface of the second substrate  121  on which the second contact pads  123  are arranged. The second guide column  18  protrudes from the surface of the housing  11  and is fitted into the second guide hole  124  of the second substrate  121 . The positioning of the housing  11  with respect to the second substrate  121  is achieved and causes the second bending portion  58  of each terminal  51  to contact the surface of the corresponding second contact pad  123 . The upper end surface of the annular protrusion  17   a  protruding from the surface of the housing  11  abuts the second substrate  121 , thus keeping the spacing between the housing  11  and the second substrate  121 . 
     Finally, the fastening members  131  are inserted into the mounting holes  17 , the first mounting holes  112  and the second mounting holes  122  and nuts  132  are screwed onto the fastening members  131  to fasten the first and second substrates  111 , 121  together. Where the first substrate  111  and the second substrate  121  are gradually fastened together, the second bending portion  53  of each terminal  51  is pushed up by the first contact pad  113  of the first substrate  111  and the second bending portion  58  and the tilting portion  57  of the terminal  51  are tilted by the second contact pad  123  of the second substrate  121  and are deformed downward. In this process, a stress is exerted on the terminal  51  in the tilting direction of the tilting portion  57  so that the side surfaces of upper convex portion  55   a  and the lower convex portion  55   b  of the mounting portion  54  are pressed by the side surface of the broad width part  14  close to the narrow part. The housing  11  of the connector  1  includes a cavity  12  in the housing  11  in the direction of thickness and accommodating the terminal  51 . The terminal  51  includes a mounting portion  54  that is bifurcated by a vertical slot  54   a  and the mounting portion  54  includes concave portions  56  formed on its outer edges. The cavity  12  is provided with the broad width part  14  having a width larger than that of the mounting portion  54  to accommodate the mounting portion  54 . The convex part  15  protruding inward from the inner side surface of the broad width part  14  is engaged with a concave portion  56  to hold the terminal  51  so as to allow it to move vertically and horizontally. 
     Even if the housing  11 , the first substrate  111  or the second substrate  121  is distorted or warped, it is possible to appropriately absorb variation in the spacing between the first or second substrate  111 , 121  and the housing  11  thereby keeping contact between the first substrate  111  and the second substrate  121 . It is also possible to simplify the structure of the connector  1 , thus reducing costs. 
     The terminal  51  includes the first bending portion  53  connected to an end of the mounting portion  54  close to the first substrate  111 , a body portion  52  whose end close to the first substrate  111  is connected to the first bending portion  53 , the tilting portion  57  connected to the end of the body portion  52  close to the second substrate  121  and tilting in a direction opposite to the bending direction of the first bending portion  53 , and the second bending portion  58  connected to the end of the tilting portion  57  close to the second substrate  121  and bent in a direction opposite to the bending direction of the first bending portion  53 . The first bending portion  53  of the terminals  51  contacts the first contact pads  113  and the second bending portions  58  contact the second contact pads  123 , causing the terminal  51  to elastically deform and absorb any variation in the distance between the first and second contact pads  113 , 123 . 
     In this way, the terminal  51  is deformed elastically and flexibly. Even when the spacing between the housing  11  and the first or second substrate  111 , 121  are not constant, the first and second bending portions  53 , 58  of each terminal  51  can contact with corresponding first and second contact pad  113 , 123 . Thus, even where the housing  11 , the first substrate  111  or the second substrate  121  are distorted or warped, it is possible to reliably connect the first and second substrates  111 , 121 . Elastic force generated by the elastic deformation of the terminals  51  energizes the first and second bending portions  53 , 58  toward the first and second contact pads  113 , 123 , which ensures contact with the first and second contact pads  123 . A change in the inclination of the tilting portions  57  generates a wiping effect that removes any foreign substance attached to the surfaces of the second bending portions  58  and the second contact pads  123  that hampers electrical continuity. This ensures continuity between the second bending portions  58  and the second contact pads  123 . 
       FIG. 12  is a perspective view showing a terminal according to the second embodiment of the present invention. As shown in  FIG. 12 , a protrusion  59  is formed at the lower end of a first bending portion  53  and also at the upper end of a second bending portion  58  of a terminal  51 . The protrusions  59  come into contact with the first and second contact pads  113 , 123  so that the contact pressure per unit area is higher, which further ensures electric connection between the first bending portion  53  and the second bending portion  58  and the first and second contact pad  113 , 123  respectively. Other configurations and operations are the same as those in the afore-described first embodiment so that corresponding description is omitted. 
     The present invention is not limited to the above-described embodiments, and may be changed and modified in various ways based on the gist of the present invention, and these changes and modifications should not be eliminated from the scope of the present invention as defined by the appended claims.