Patent Publication Number: US-10312616-B2

Title: Card edge connector

Description:
RELATED APPLICATIONS 
     This application claims priority to Chinese Application No. 201710574511.8, filed Jul. 14, 2017, which is incorporated herein by reference in its entirety. 
     TECHNICAL FIELD 
     The present disclosure relates to a card edge connector, especially to a card edge connector used for assembling a card edge module. 
     BACKGROUND ART 
       FIG. 1  is a structural schematic view of a terminal  11  of an existing card edge connector which is disclosed in U.S. Pat. No. 4,832,617 (corresponding to Taiwanese patent application No. TW77211193). Referring to  FIG. 1 , the terminal  11  is a terminal in form of a planar conductive member, which has a central cutout  10  to form planar beam sections  12 A and  12 B generally parallel to each other and spaced apart from each other, and ends of the planar beam sections  12 A and  12 B away from the base  14  are connect together at a part  16 . The planar beam sections  12 A and  12 B both have uniform and identical widths (i.e., a width W 0  of the planar beam section  12 A is the same as a width W 0 ′ of the planar beam section  12 B) along a length direction, the central cutout  10  is positioned between adjacent edges of the two planar beam sections  12 A and  12 B, and has a width which is substantially the same as the width of each of the planar beam sections  12 A and  12 B. One of the planar beam sections  12 A and  12 B is subjected to a tensile force, and the other of the planar beam sections  12 A and  12 B is subjected to a compressive force. 
     Since the widths of the generally parallel planar beam sections  12 A and  12 B of the terminal  11  are the same, a stress applied by the board  18  to the planar beam sections  12 A and  12 B is relatively easy to exceed a stress that the planar beam section  12 A and  12 B can bear when a board card  18  is inserted in or pulled out, thereby causing the permanent deformation of the terminal  11 , especially such a permanent deformation more easily occur at bending locations of the two planar beam sections  12 A and  12 B. The tensile forces and compressive forces to which the planar beam sections  12 A and  12 B are subjected are different, of course, one way is to increase the widths and thicknesses of the planar beam section  12 A and  12 B at the same time to overcome the maximum plastic deformation of the planar beam section  12 A and  12 B, but if it does so, the connector and terminal will be difficult to design smaller and more compact. 
       FIG. 2  is a structural schematic view of terminals  2 A and  2 B of an existing card edge connector which is disclosed in Chinese patent application No. CN201480045224.2 (corresponding to United States patent publication No. US2016/0181713 and Taiwanese patent application No. TW103127051). Referring to  FIG. 2 , a terminal  2 A comprises a contact portion  20 A, and a terminal  2 B comprises a contact portion  20 B. The contact portions  20 A and  20 B are formed as a loop and comprise back frames  22 A and  22 B which help support the contact portions  20 A and  20 B. 
     However, similarly, since a width of the contact portion  20 A of the terminal  2 A is the same as a width of the contact portion  20 B of the terminal  2 B, the stresses applied by the board card to the contact portion  20 A of the terminal  2 A and the contact portion  20 B of the terminal  2 B are relatively easy to respectively exceed stresses that the contact portion  20 A of the terminal  2 A and the contact portion  20 B of the terminal  2 B can bear when a board card (not shown) is inserted into or pulled out, thereby causing the permanent deformation of the terminal  2 A and the permanent deformation of the terminal  2 B, and such a permanent deformation is more easily occur respectively at bending locations of the terminal  2 A and the terminal  2 B. 
     The description in background as above merely is used to provide a background art, and it does not admit that the description on the background art as above discloses the object of the present disclosure, and do not constitute a prior art of the present disclosure, and any description in background as above shall not be acted as any part of the present disclosure. 
     SUMMARY 
     The embodiments of the present disclosure provide a card edge connector. The card edge connector comprises an insulating housing and a plurality of flat plate-shaped terminals. The insulating housing is formed as an elongated shape extending along a longitudinal direction, the insulating housing has a top surface and a bottom surface which define an up-down direction, the insulating housing has a card edge inserting groove on the top surface along the longitudinal direction, the card edge inserting groove separates the insulating housing into a first wall body and a second wall body, a direction that the first wall body and the second wall body face each other defining a transversal direction, a direction that each of the first wall body and the second wall body faces the card edge inserting groove is an inner direction, and a direction that each of the first wall body and the second wall body is away from the card edge inserting groove is an outer direction, at least one of the first wall body and the second wall body has a plurality of terminal grooves which are arranged side by side in the longitudinal direction and each are provided in the transversal direction. Each flat plate-shaped terminal is mounted in the corresponding terminal groove, an extending direction of a plate surface of each flat plate-shaped terminal is parallel to the transversal direction, each flat plate-shaped terminal comprises a base portion, a contact portion and an elastic arm portion. The base portion is positioned at a lower side of the flat plate-shaped terminal. The contact portion is positioned above the base portion and extends into the card edge inserting groove. The elastic arm portion is positioned between the base portion the contact portion, the elastic arm portion sequentially comprises a lower reverse bent section, an outward inclined arm section, an upper reverse bent section and an inward inclined arm section. The lower reverse bent section connects the base portion, extends from the base portion toward the inner direction, reversely bends, and extends toward the outer direction and an inclined upward direction. The outward inclined arm section extends toward the outer direction and the inclined upward direction. The upper reverse bent section reversely bends and extends toward the inner direction and an inclined downward direction. The inward inclined arm section extends toward the inner direction and the inclined downward direction. The elastic arm portion is a two-arm configuration with a closed loop, the two-arm configuration has an inner arm and an outer arm, the inner arm and the outer arm are arranged along an overall profile of each flat plate-shaped terminal and have different profiles, the inner arm and the outer arm each have the corresponding lower reverse bent section, the corresponding outward inclined arm section, the corresponding upper reverse bent section and the corresponding inward inclined arm section which respectively correspond to the sections of the elastic arm portion. 
     In the embodiments of the present disclosure, the outward inclined arm section of the outer arm is spaced apart from the outward inclined arm section of the inner arm by a first spacing, the upper reverse bent section of the outer arm is spaced apart from the upper reverse bent section of the inner arm by a second spacing, the inward inclined wall section of the outer arm is spaced apart from the inward inclined wall section of the inner arm by a third spacing, and the second spacing is larger than the first spacing and the third spacing. 
     In the embodiments of the present disclosure, a thickness refers to a plate thickness of each flat plate-shaped terminal, and a width refers to a width of each section of each flat plate-shaped terminal along a plate surface direction. The width of the upper reverse bent section of the inner arm is the largest among the sections of the inner arm and the sections of the outer arm, the width of the lower reverse bent section of the inner arm is the smallest among the sections of the inner arm, and the width of the lower reverse bent section of the outer arm is the smallest among the sections of the outer arm, the width of the lower reverse bent section of the inner arm is larger than or equal to the width of the lower reverse bent section of the outer arm, the width of the outward inclined arm section of the inner arm is larger than or equal to the width of the outward inclined arm section of the outer arm, the width of the inward inclined arm section of the inner arm is larger than or equal to the width of the inward inclined arm section of the outer arm. 
     In the embodiments of the present disclosure, the second spacing is larger than the first spacing, and the first spacing is larger than the third spacing. 
     In the embodiments of the present disclosure, the width of the lower reverse bent section of the inner arm is equal to the width of the lower reverse bent section of the outer arm. 
     In the embodiments of the present disclosure, a ratio of the width of the inner arm to the thickness of the inner arm range from 1.3 to 2.3, and a ratio of the width of the outer arm to the thickness of the outer arm range from 1.3 to 2.3. 
     In the embodiments of the present disclosure, the contact portion has a contact edge and a guide edge, the guide edge is positioned above the contact edge. The plurality of flat plate-shaped terminals comprise a first row of flat plate-shaped terminals and a second row of flat plate-shaped terminal, each flat plate-shaped terminal of the first row is mounted in each terminal groove of the first wall body, each flat plate-shaped terminal of the second row is mount in each terminal groove of the second wall body. A height of the contact portion of each flat plate-shaped terminal of the first row is lower than a height of the contact portion of each flat plate-shaped terminal of the second row. A sharp angle between the guide edge of each flat plate-shaped terminal of the first row and the up-down direction is larger than a sharp angle between the guide edge of each flat plate-shaped terminal of the second row and the up-down direction. The width of the upper reverse bent section of the inner arm of each flat plate-shaped terminal of the first row is larger than the width of the upper reverse bent section of the inner arm of each flat plate-shaped terminal of the second row. 
     In the embodiments of the present disclosure, the width of the inward inclined arm section of the inner arm of each flat plate-shaped terminal of the second row is larger than the width of the inward inclined arm section of the inner arm of each flat plate-shaped terminal of the first row. The width of the inward inclined arm section of the outer arm of each flat plate-shaped terminal of the first row is equal to the width of the upper reverse bent section of the outer arm of each flat plate-shaped terminal of the first row, the width of the inward inclined arm section of the outer arm of each flat plate-shaped terminal of the second row is equal to the width of the upper reverse bent section of the outer arm of each flat plate-shaped terminal of the second row, the width of the inward inclined arm section of the outer arm of each flat plate-shaped terminal of the first row is larger than the width of the inward inclined arm section of the outer arm of each flat plate-shaped terminal of the second row. The width of the outward inclined arm section of the inner arm of each flat plate-shaped terminal of the first row is larger than or equal to the width of the outward inclined arm section of the inner arm of each flat plate-shaped terminal of the second row. The width of the lower reverse bent section of the outer arm of each flat plate-shaped terminal of the first row, the width of the lower reverse bent section of the inner arm of each flat plate-shaped terminal of the first row, the width of the lower reverse bent section of the outer arm of each flat plate-shaped terminal of the second row, the width of the lower reverse bent section of the inner arm of each flat plate-shaped terminal of the second row, the width of the outward inclined arm section of the outer arm of each flat plate-shaped terminal of the first row, the width of the outward inclined arm section of the outer arm of each flat plate-shaped terminal of the second row and the width of the outward inclined arm section of the inner arm of each flat plate-shaped terminal of the second row are equal to each other. 
     In the embodiments of the present disclosure, in each flat plate-shaped terminal of the first row: the width of the upper reverse bent section of the inner arm is larger than the width of the upper reverse bent section of the outer arm, the width of the inward inclined arm section of the inner arm is equal to the width of the inward inclined arm section of the outer arm, the width of the outward inclined arm section of the inner arm is larger than or equal to the width of the outward inclined arm section of the outer arm, the width of the lower reverse bent section of the inner arm is equal to the width of the lower reverse bent section of the outer arm; the width of the upper reverse bent section of the inner arm is larger than the width of the inward inclined arm section of the inner arm, the width of the inward inclined arm section of the inner arm is larger than or equal to the width of the outward inclined arm section of the inner arm, the width of the outward inclined arm section of the inner arm is larger than or equal to the width of the lower reverse bent section of the inner arm; the width of the upper reverse bent section of the outer arm is equal to the width of the inward inclined arm section of the outer arm, the width of the inward inclined arm section of the outer arm is larger than the width of the outward inclined arm section of the outer arm, the width of the outward inclined arm section of the outer arm is equal to the width of the lower reverse bent section of the outer arm; the ratio of the width of the inner arm to the thickness of the inner arm and the ratio of the width of the outer arm to the thickness of the outer arm each range from 1.3 to 2.3. In each flat plate-shaped terminal of the second row: the width of the upper reverse bent section of the inner arm is larger than the width of the upper reverse bent section of the outer arm, the width of the inward inclined arm section of the inner arm is larger than the width of the inward inclined arm section of the outer arm, the width of the outward inclined arm section of the inner arm is equal to the width of the outward inclined arm section of the outer arm, the width of the lower reverse bent section of the inner arm equal to the width of the lower reverse bent section of the outer arm; the width of the upper reverse bent section of the inner arm is equal to the width of the inward inclined arm section of the inner arm, the width of the inward inclined arm section of the inner arm is larger than the width of the outward inclined arm section of the inner arm, the width of the outward inclined arm section of the inner arm is equal to the width of the lower reverse bent section of the inner arm; the width of the upper reverse bent section of the outer arm is equal to the width of the inward inclined arm section of the outer arm, the width of the inward inclined arm section of the outer arm is equal to the width of the outward inclined arm section of the outer arm, the width of the outward inclined arm section of the outer arm is equal to the width of the lower reverse bent section of the outer arm; the ratio of the width of the inner arm to the thickness of the inner arm and the ratio of the width of the outer arm to the thickness of the outer arm each range from 1.3 to 2.0. 
     In the embodiments of the present disclosure, each flat plate-shaped terminal further comprises a holding portion, the holding portion is configured to be interference fixed with the insulating housing. 
     In the embodiments of the present disclosure, the holding portion is integrally formed with the flat plate-shaped terminal. 
     In the embodiments of the present disclosure, the card edge connector further comprises a plurality of support blocks, each support block is positioned between the base portion and the holding portion, each terminal groove further comprises a support block receiving groove, the support block receiving grooves are communicated with each other, the support blocks are arranged side by side along the longitudinal direction in the support block receiving grooves which are communicated with each other. 
     In the embodiments of the present disclosure, the holding portion further comprises an interference protrusion, and wherein each support block receiving groove further comprises a shallow groove, the interference protrusion is interference fixed with the shallow groove. 
     In the embodiments of the present disclosure, each flat plate-shaped terminal further comprises a tail portion, the insulating housing further comprises a plurality of terminal tail portions fixing grooves, the terminal tail portion fixing groove is configured to position and receive the tail portion of the flat plate-shaped terminal. 
     In the embodiments of the present disclosure, an upper end of an inside of the first wall body has an inclined insertion guiding surface toward the card edge inserting groove. 
     In the embodiments of the present disclosure, each flat plate-shaped terminal is a two-arm configuration with a closed loop. The two-arm configuration has the inner arm and the outer arm arranged along the overall profile of each flat plate-shaped terminal. The inner arm and the outer arm of each flat plate-shaped terminal have different profiles, and the inner arm and the outer arm each can have different widths of the sections (that is, the width of the lower reverse bent section, the width of the outward inclined arm section, the width of the upper reverse bent section and the width of the inward inclined arm section are different). In addition, in some corresponding arm sections, the width of a section of the inner arm is larger than the width of a corresponding section of the outer arm, and in some sections, the outer arm is spaced apart from the inner arm by a relatively large spacing, such as the second spacing. Accordingly, the two-arm configuration with the closed loop of the flat plate-shaped terminal can control the deflection behavior of the flat plate-shaped terminal, prevent the excessive deflection of the flat plate-shaped terminal and in turn avoid permanent deformation of the flat plate-shaped terminal. 
     Relatively, in some existing terminals, since the widths of the two generally parallel planar beam sections of the terminal are the same, the stress applied by the board card to the two planar beam sections is relatively easy to exceed the stress that the two planar beam sections can bear when the board card is inserted in or pulled out, thereby causing the permanent deformation of the terminal, and such a permanent deformation is more easily occur at the bending locations of the two planar beam sections. 
     Technical features and advantages of the present disclosure are widely summarized as above, so as to better understand the following detailed description. Other technical feature making up technical solutions of the claims of the present disclosure and other advantages will be described below. A person skilled in the art of the present disclosure shall understand that the concept and specific embodiments disclosed below may be easily used to modify or design other configuration or manufacturing approach so as to realize the same object as the present disclosure. A person skilled in the art of the present disclosure shall also understand that, such an equivalent configuration or approach cannot be departed from the spirit and scope of the present disclosure defined by the appended claims. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The various respects of the present disclosure may be best understood by the following detailed description taken in connection with the accompanying figures. It should be noted that, according to a standard implementing mode of the industries, features are not drawn as the scale. In practice, for the sake of clear explanation, various features may be arbitrarily enlarged or reduced in dimension. 
         FIG. 1  is a structural schematic view of a terminal of an existing card edge connector. 
         FIG. 2  is a structural schematic view of a terminal of an existing card edge connector. 
         FIG. 3  is a top perspective schematic view of a card edge connector of an embodiment of the present disclosure. 
         FIG. 4  is a bottom perspective schematic view of the card edge connector of  FIG. 3 . 
         FIG. 5  is a top exploded schematic view of the card edge connector of  FIG. 4 . 
         FIG. 6  is a bottom exploded perspective schematic view of the card edge connector of  FIG. 4 . 
         FIG. 7  is a cross sectional perspective schematic view taken along a line A-A of the card edge connector of  FIG. 5 . 
         FIG. 8  is a cross sectional perspective schematic view after the flat plate-shaped terminals of the card edge connector of  FIG. 7  are assembled. 
         FIG. 9  is a planar cross sectional schematic view of the card edge connector of  FIG. 8 . 
         FIG. 10  is a top perspective schematic view of the flat plate-shaped terminal of the card edge connector of  FIG. 4 . 
         FIG. 11  is a top exploded perspective schematic view of the flat plate-shaped terminal of the card edge connector of  FIG. 4 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The following disclosed content provides various embodiments or exemplifications used to implement various features of the present disclosure. Specific examples of elements and arrangements are described as follows, so as to simplify the disclosed content of the present disclosure. Certainly, these are merely examples, and are not used to limit the present disclosure. For example, in the following description, that a first feature is formed on or above a second feature may comprise an embodiment that the first feature and the second are formed to directly contact with each other, may also comprise an embodiment that other feature is formed between the first feature and the second feature, therefore the first feature and the second feature do not directly contact with each other. Moreover, the present disclosure may allow a symbol and/or a character of an element to be repeated in different examples. The repetition is used for simplification and clearness, but is not used to dominate a relationship between various embodiments and/or discussed structures. 
     Moreover, the present disclosure may use spatial corresponding terminologies, such as “below”, “lower than”, “relative lower”, “higher than”, “relative high” and the like, so as to describe a relationship between an element or feature and another element or feature. Spatial corresponding terminologies are used to comprise various orientations of an apparatus in use or operation besides orientations illustrated in figures. Or the apparatus may be orientated (rotated by 90 degrees or at other orientation), and the corresponding spatial description in the present disclosure may be correspondingly explained. It should be understood that, when a feature is formed to another feature or above a substrate, other feature may be presented between them. 
       FIG. 3  is a top perspective schematic view of a card edge connector  3  of embodiments of the present disclosure, the card edge connector  3  is mounted on a carrier board  5  and receives a card edge module  4 . Referring to  FIG. 3 , although  FIG. 3  shows an arrangement of the two card edge modules  4 , it does not mean that the two card edge modules  4  are inserted into the card edge connector  3  at one time. Furthermore, the arrangement of the two card edge modules  4  is only for indicating that the card edge module  4  is inserted into the card edge connector  3  at a position between a position  4 ′ and a position  4 ″ and remains the orientation in an insertion direction. In some embodiments, the carrier board  5  comprises a printed circuit board (PCB). 
       FIG. 4  is a bottom perspective schematic view of the card edge connector  3  of  FIG. 3 .  FIG. 5  is a top exploded schematic view of the card edge connector  3  of  FIG. 4 .  FIG. 6  is a bottom exploded perspective schematic view of the card edge connector  3  of  FIG. 4 . Referring to  FIG. 4  to  FIG. 6 , the card edge connector  3  comprises an insulating housing  7 , a plurality of flat plate-shaped terminals  9  and two auxiliary fixing members  6 . Referring back to  FIG. 3 , the flat plate-shaped terminals  9  are mounted in the insulating housing  7  and are fixed on the carrier board  5 , and the two auxiliary fixing members  6  assist the insulating housing  7  to be fixed on the carrier board  5 . 
     The insulating housing  7  is formed as an elongated shape extending along a longitudinal direction and has a top surface  70  and a bottom surface  72  which define an up-down direction. The insulating housing  7  has a card edge inserting groove  74  on the top surface  70  along the longitudinal direction, the card edge inserting groove  74  is configured to receive the card edge module  4  (referring to  FIG. 3 ). 
       FIG. 7  is a cross sectional perspective schematic view taken along a line A-A of the card edge connector  3  of  FIG. 5 , in which only a perspective cross section of the insulating base  7  and a situation where one pair of the flat plate-shaped terminals  9  are separated from the terminal grooves  78  of the insulating base  7  are shown.  FIG. 8  is a cross sectional perspective schematic view after the flat plate-shaped terminals  9  of the card edge connector  3  of  FIG. 7  are assembled.  FIG. 9  is a planar cross sectional schematic view of the card edge connector  3  of  FIG. 8 . 
     Referring to  FIG. 7  to  FIG. 9 , the card edge inserting groove  74  separates the insulating housing  7  into a first wall body  74 A and a second wall body  74 B. A direction that the first wall body  74 A and the second wall body  74 B face each other defines a transversal direction. The insulating housing  7  has a plurality of terminal grooves  78 , each of the first wall body  74 A and the second wall body  74 B has the terminal grooves  78  which are arranged side by side in the longitudinal direction and each are provided in the transversal direction. The plurality of flat plate-shaped terminals  9  comprise a first row  1  of flat plate-shaped terminals and a second row  2  of flat plate-shaped terminals. Each flat plate-shaped terminal of the first row  1  is mounted in each terminal groove  78  of the first wall body  74 A, and each flat plate-shaped terminal of the second row  2  is mounted in each terminal groove  78  of the second wall body  74 B. An extending direction of a plate surface of each flat plate-shaped terminal  9  is parallel to the transversal direction. In an embodiment, each flat plate-shaped terminal of the first row  1  is different each flat plate-shaped terminal of the second row  2  in profile. In another embodiment, each flat plate-shaped terminal of the first row  1  can be the same as each flat plate-shaped terminal of the second row  2  in profile. In addition, a direction that each of the first wall body  74 A and the second wall body  74 B faces the card edge inserting groove  74  is an inner direction R 1 , and a direction that each of the first wall body  74 A and the second wall body  74 B is away from the card edge inserting groove  74  is an outer direction R 2 . Also, an upper end of an inside  93  of the first wall body  74 A of the insulating housing  7  has an inclined insertion guiding surface  77  toward the card edge inserting groove  74 . The inclined insertion guiding surface  77  is configured to guide the card edge module  4  when the card edge module  4  is inclined and inserted into the card edge inserting groove  74 . 
     Hereinafter, referring to  FIG. 9  and  FIG. 10 , common structural features of the flat plate-shaped terminals  9  will be first described, and hereinafter the flat plate-shaped terminal of the first row  1  is taken as an example, and these structural features are also applicable to the flat plate-shaped terminal of the second row  2 .  FIG. 10  is a top perspective schematic view of the flat plate-shaped terminal  9  of the card edge connector  3  of  FIG. 4 . 
     Each flat plate-shaped terminal  9  comprises a base portion  30 , a contact portion  40 , an elastic arm portion  50 , a tail portion  60 . The base portion  30  is positioned at a lower side of the flat plate-shaped terminal  9 . The contact portion  40  is positioned above the base portion  30  and extends into the card edge inserting groove  74  toward the inner direction R 1 , as shown in  FIG. 7  to  FIG. 9 . The elastic arm portion  50  is positioned between the base portion  30  and the contact portion  40 . The contact portion  40  has a contact edge  42  and a guide edge  44 . The guide edge  44  is positioned above the contact edge  42 , the guide edge  44  is configured to guide the card edge module  4  when the card edge module  4  is inserted into the card edge inserting groove  74 . In some embodiments, the tail portion  60  comprises a surface-soldering tail portion, and the flat plate-shaped terminal  9  is fixed on the carrier board  5  by soldering the surface-soldering tail portion on the carrier board  5 . 
     The elastic arm portion  50  sequentially comprises a lower reverse bent section, an outward inclined arm section, an upper reverse bent section and an inward inclined arm section. The lower reverse bent section connects one end of the base portion  30  in the inner direction R 1 , extends from the base portion  30  toward the inner direction R 1 , bends reversely and extends toward the outer direction R 2  and an inclined upward direction. The outward inclined arm section extends toward the outer direction R 2  and the inclined upward direction. The upper reverse bent section bends reversely and extends toward the inner direction R 1  and an inclined downward direction. The inward inclined arm section extends toward the inner direction R 1  and the inclined downward direction. 
     Furthermore, the elastic arm portion  50  is a two-arm configuration with a closed loop. The two-arm configuration has an inner arm and an outer arm, the inner arm and the outer arm are arranged along an overall profile of each flat plate-shaped terminal  9  and have different profiles. The inner arm and the outer arm each have the corresponding lower reverse bent section, the corresponding outward inclined arm section, the corresponding upper reverse bent section and the corresponding inward inclined arm section, which will be described in detail below. 
     Hereinafter, a thickness T, a width W, a height L of the flat plate-shaped terminal  9  will be discussed. The thickness T refers to a plate thickness of the flat plate-shaped terminal  9 , that is a thickness of the flat plate-shaped terminal  9  in the longitudinal direction, the width W refers to a width of each section of the flat plate-shaped terminal  9  along a plate surface direction, the height L refers to a distance between an upper end of the upper reverse bent section  56  of the flat plate-shaped terminal  9  and a lower end of the base portion  30  in an up-down direction, that is a total height of the flat plate-shaped terminal  9 . In the embodiment, the flat plate-shaped terminal  9  is formed by blanking and stamping a plate, thus the base portion  30 , the lower reverse bent section, the outward inclined arm section, the upper reverse bent section, the inward inclined arm section and the contact portion  40  of the flat plate-shaped terminal  9  all have the same thicknesses T and are positioned on the same plate surface. 
     Referring to  FIG. 9  and  FIG. 10 , the common structural features which the sections of the arm of each flat plate-shaped terminal of the first row  1  and the sections of the arm of each flat plate-shaped terminal of the second row  2  in the width W have will be described below. As above, hereinafter each flat plate-shaped terminal of the first row  1  is taken as an example, for the sake of convenient discussion, the internal structures of the flat plate-shaped terminal of the first row  1  are marked as follows: the outer arm is marked as A 1  and the inner arm is marked as B 1 ; the lower reverse bent section of the outer arm A 1  is marked as  52 A, the outward inclined arm section is marked as  54 A, the upper reverse bent section is marked as  56 A, the inward inclined arm section is marked as  58 A; and the lower reverse bent section of the inner arm B 1  is marked as  52 B, the outward inclined arm section is marked as  54 B, the upper reverse bent section is marked as  56 B, the inward inclined arm section is marked as  58 B. The common structural features can be represented as: 
     (1) The width W of the upper reverse bent section  56 B of the inner arm B 1  is the largest among the sections of the inner arm B 1  and the sections of the outer arm A 1 ; and the width W of the upper reverse bent section  56 B of the inner arm B 1  is larger than the width W of the upper reverse bent section  56 A of the outer arm A 1 . 
     (2) The width W of the lower reverse bent section  52 B of the inner arm B 1  is the smallest among the sections of the inner arm B 1 ; and, the width W of the lower reverse bent section  52 A of the outer arm A 1  is the smallest among the sections of the outer arm A 1 . 
     (3) The width W of the lower reverse bent section  52 B of the inner arm B 1  is larger than or equal to the width W of the lower reverse bent section  52 A of the outer arm A 1 ; in an embodiment, the width W of the lower reverse bent section  52 B of the inner arm B 1  is equal to the width W of the lower reverse bent section  52 A of the outer arm A 1 . 
     (4) The width W of the outward inclined arm section  54 B of the inner arm B 1  is larger than or equal to the width W of the outward inclined arm section  54 A of the outer arm A 1 , the width W of the inward inclined arm section  58 B of the inner arm B 1  is larger than or equal to the width W of the inward inclined arm section  58 A of the outer arm A 1 . 
     (5) The outward inclined arm section  54 A of the outer arm A 1  is spaced apart from the outward inclined arm section  54 B of the inner arm B 1  by a first spacing S 11 , the upper reverse bent section  56 A of the outer arm A 1  is spaced apart from the upper reverse bent section  56 B of the inner arm B 1  by a second spacing S 12 , the inward inclined wall section  58 A of the outer arm A 1  is spaced apart from the inward inclined wall section  58 B of the inner arm B 1  by a third spacing S 13 . And the second spacing S 12  is larger than the first spacing S 11  and the third spacing S 13 . In an embodiment, the second spacing S 12  is larger than the first spacing S 11 , and the first spacing S 11  is larger than the third spacing S 13 ; accordingly, it is possible to prevent the outer arm A 1  and the inner arm B 1  from interfering with each other when the flat plate-shaped terminal  9  is elastically deformed. 
     (6) The ratio of the width W of the inner arm B 1  to a thickness T of the inner arm B 1  ranges from 1.3 to 2.3, and a ratio of the width W of the outer arm A 1  to a thickness T of the outer arm A 1  ranges from 1.3 to 2.3. 
     In conclusion, in the present disclosure, the flat plate-shaped terminal  9  is a two-arm configuration with a closed loop, the two-arm configuration has the inner arm B 1  and the outer arm A 1  which are arranged along the overall profile of the flat plate-shaped terminal  9 . The inner arm B 1  and the outer arm A 1  of the flat plate-shaped terminal  9  have different profiles, and the inner arm B 1  and the outer arm A 1  each can have the different widths of the sections. In addition, in some corresponding sections, the width W of a section of the inner arm B 1  is larger than the width W of the corresponding section of the outer arm A 1 , and in some sections, the outer arm A 1  is spaced apart from the inner arm B 1  by a relatively large spacing, such as the second spacing S 12 . Accordingly, the behavior of the deflection of the flat plate-shaped terminal  9  can be controlled to prevent excessive deflection of the flat plate-shaped terminal  9  and in turn to avoid permanent deformation of the flat plate-shaped terminal  9 . 
     In an embodiment, each flat plate-shaped terminal of the first row  1  and each flat plate-shaped terminal of the second row  2  have different profiles. For the sake of convenient discussion, referring back to  FIG. 10  and  FIG. 11 , the internal structures of the flat plate-shaped terminal of the second row  2  is marked as follows: the outer arm is marked as A 2  and the inner arm is marked as B 2 ; the lower reverse bent section of the outer arm A 2  is marked as  53 A, the outward inclined arm section is marked as  55 A, the upper reverse bent section is marked as  57 A, the inward inclined arm section is marked as  59 A; and, the lower reverse bent section of the inner arm B 2  is marked as  53 B, the outward inclined arm section is marked as  55 B, the upper reverse bent section is marked as  57 B, the inward inclined arm section is marked as  59 B. Referring to  FIG. 9 , a relationship between the widths W of sections of the arms of each flat plate-shaped terminal of the first row  1  and widths W of sections of the arms of each flat plate-shaped terminal of the second row  2  can be represented as follows: 
     (1) The width W of the upper reverse bent section  56 B of the inner arm B 1  of each flat plate-shaped terminal of the first row  1  is larger than the width W of the upper reverse bent section  57 B of the inner arm B 2  of each flat plate-shaped terminal of the second row  2 . 
     (2) The width W of the inward inclined arm section  59 B of the inner arm B 2  of each flat plate-shaped terminal of the second row  2  is larger than the width W of the inward inclined arm section  58 B of the inner arm B 1  of each flat plate-shaped terminal of the first row  1 . 
     (3) The width W of the inward inclined arm section  58 A of the outer arm A 1  of each flat plate-shaped terminal of the first row  1  is equal to the width W of the upper reverse bent section  56 A of the outer arm A 1  of each flat plate-shaped terminal of the first row  1 , the width W of the inward inclined arm section  59 A of the outer arm A 2  of each flat plate-shaped terminal of the second row  2  is equal to the width W of the upper reverse bent section  57 A of the outer arm A 2  of each flat plate-shaped terminal of the second row  2 , and the width W of the inward inclined arm section  58 A of the outer arm A 1  and the width W of the upper reverse bent section  56 A of the outer arm A 1  of each flat plate-shaped terminal of the first row  1  is larger than the width W of the inward inclined arm section  59 A of the outer arm A 2  and the upper reverse bent section  57 A of the outer arm A 2  of each flat plate-shaped terminal of the second row  2 . 
     (4) The width W of the outward inclined arm section  54 B of the inner arm B 1  of each flat plate-shaped terminal of the first row  1  is larger than or equal to the width W of the outward inclined arm section  55 B of the inner arm B 2  of each flat plate-shaped terminal of the second row  2 . 
     (5) The width W of the lower reverse bent section  52 A of the outer arm A 1  of each flat plate-shaped terminal of the first row  1 , the width W of the lower reverse bent section  52 B of the inner arm B 1  of each flat plate-shaped terminal of the first row  1 , the width W of the lower reverse bent section  53 A of the outer arm A 2  of each flat plate-shaped terminal of the second row  2 , the width W of the lower reverse bent section  53 B of the inner arm B 2  of each flat plate-shaped terminal of the second row  2 , the width W of the outward inclined arm section  54 A of the outer arm A 1  of each flat plate-shaped terminal of the first row  1 , the width W of the outward inclined arm section  55 A of the outer arm A 2  of each flat plate-shaped terminal of the second row  2  and the width W of the outward inclined arm section  55 B of the inner arm B 2  of each flat plate-shaped terminal of the second row  2  are equal to each other. 
     (6) A height of the contact portion  40  of each flat plate-shaped terminal of the first row  1  is lower than a height of the contact portion  40  of each flat plate-shaped terminal of the second row  2 . 
     (7) A sharp angle between the guide edge  44  of each flat plate-shaped terminal of the first row  1  and the up-down direction is larger than a sharp angle between the guide edge  44  of each flat plate-shaped terminal of the second row  2  and the up-down direction, in other words, the guide edge  44  of each flat plate-shaped terminal of the second row  2  is steeper than the guide edge  44  of each flat plate-shaped terminal of the second row  2  toward the inward and the downward. 
     A relationship of the profile of each flat plate-shaped terminal of the first row  1  and a relationship the profile of each flat plate-shaped terminal of the second row  2  will be respectively described below. 
     In each flat plate-shaped terminal of the first row  1 : 
     (1) A ratio of the width W of the inner arm B 1  to the thickness T of the inner arm B 1  and a ratio of the width W of the outer arm A 1  to the thickness T of the outer arm A 1  each range from 1.3 to 2.3. In some embodiments, one endpoint value of the range of the ratio is not limited to 1.3 and can be any value between 1.3 and 2.3. In some embodiments, the other endpoint value of the range of the ratio is not limited to 2.3 and can be any value between 1.3 and 2.3. 
     (2) The width W of the upper reverse bent section  56 B of the inner arm B 1  is larger than the width W of the upper reverse bent section  56 A of the outer arm A 1 , the width W of the inward inclined arm section  58 B of the inner arm B 1  is equal to the width W of the inward inclined arm section  58 A of the outer arm A 1 , the width W of the outward inclined arm section  54 B of the inner arm B 1  is larger than or equal to the width W of the outward inclined arm section  54 A of the outer arm A 1 , and the width W of the lower reverse bent section  52 B of the inner arm B 1  is equal to the width W of the lower reverse bent section  52 A of the outer arm A 1 . 
     (3) The width W of the upper reverse bent section  56 B of the inner arm B 1  is larger than the width W of the inward inclined arm section  58 B of the inner arm B 1 , the width W of the inward inclined arm section  58 B of the inner arm B 1  is larger than or equal to the width W of the outward inclined arm section  54 B of the inner arm B 1 , and the width W of the outward inclined arm section  54 B of the inner arm B 1  is larger than or equal to the width W of the lower reverse bent section  52 B of the inner arm B 1 . 
     (4) The width W of the upper reverse bent section  56 A of the outer arm A 1  is equal to the width W of the inward inclined arm section  58 A of the outer arm A 1 , the width W of the inward inclined arm section  58 A of the outer arm A 1  is larger than the width W of the outward inclined arm section  54 A of the outer arm A 1 , the width W of the outward inclined arm section  54 A of the outer arm A 1  is equal to the width W of the lower reverse bent section  52 A of the outer arm A 1 . 
     (5) The outward inclined arm section  54 A of the outer arm A 1  is spaced apart from the outward inclined arm section  54 B of the inner arm B 1  by a first spacing S 11 , the upper reverse bent section  56 A of the outer arm A 1  is spaced apart from the upper reverse bent section  56 B of the inner arm B 1  by a second spacing S 12 , the inward inclined wall section  58 A of the outer arm A 1  is spaced apart from the inward inclined wall section  58 B of the inner arm B 1  by a third spacing S 13 . The second spacing S 12  is larger than first spacing S 11 , and the first spacing S 11  is larger than the third spacing S 13 . 
     In each flat plate-shaped terminal of the second row  2 : 
     (1) A ratio of the width W of the inner arm B 2  to the thickness T of the inner arm B 2  and a ratio of the width W of the outer arm A 2  to the thickness T of the outer arm A 2  each range from 1.3 to 2.0. In some embodiments, one endpoint value of the range of the ratio is not limited to 1.3, which can be any value between 1.3 and 2.0. In some embodiments, the other endpoint value of the range of the ratio is not limited to 2.0, which can be any value between 1.3 and 2.0. 
     (2) The width W of the upper reverse bent section  57 B of the inner arm B 2  is larger than the width W of the upper reverse bent section  57 A of the outer arm A 2 , the width W of the inward inclined arm section  59 B of the inner arm B 2  is larger than the width W of the inward inclined arm section  59 A of the outer arm A 2 , the width W of the outward inclined arm section  55 B of the inner arm B 2  is equal to the width W of the outward inclined arm section  55 A of the outer arm A 2 , the width W of the lower reverse bent section  53 B of the inner arm B 2  is equal to the width W of the lower reverse bent section  53 A of the outer arm A 2 . 
     (3) The width W of the upper reverse bent section  57 B of the inner arm B 2  is equal to the width W of the inward inclined arm section  59 B of the inner arm B 2 , the width W of the inward inclined arm section  59 B of the inner arm B 2  is larger than the width W of the outward inclined arm section  55 B of the inner arm B 2 , the width W of the outward inclined arm section  55 B of the inner arm B 2  is equal to the width W of the lower reverse bent section  53 B of the inner arm B 2 . 
     (4) The width W of the upper reverse bent section  57 A of the outer arm A 2  is equal to the width W of the inward inclined arm section  59 A of the outer arm A 2 , the width W of the inward inclined arm section  59 A of the outer arm A 2  is equal to the width W of the outward inclined arm section  55 A of the outer arm A 2 , the width W of the outward inclined arm section  55 A of the outer arm A 2  is equal to the width W of the lower reverse bent section  53 A of the outer arm A 2 . 
     (5) The outward inclined arm section  55 A of the outer arm A 2  is spaced apart from the outward inclined arm section  55 B of the inner arm B 2  by a first spacing S 21 , the upper reverse bent section  57 A of the outer arm A 2  is spaced apart from the upper reverse bent section  57 B of the inner arm B 2  by a second spacing S 22 , the inward inclined wall section  59 A of the outer arm A 2  is spaced apart from the inward inclined wall section  59 B of the inner arm B 2  by a third spacing S 23 . The second spacing S 22  is larger than the first spacing S 21 , and the first spacing S 21  is larger than the third spacing S 23 . 
     Referring to  FIG. 11 , each flat plate-shaped terminal  9  of the card edge connector  3  further comprises a holding portion  90  extending upwardly from the base portion  30  and is configured to be interference fixed with the insulating housing  7 . The holding portion  90  further comprises an interference protrusion  92 . Each flat plate-shaped terminal  9  further comprises a support block  80 , each support block  80  is positioned between the base portion  30  and the holding portion  90  of each flat plate-shaped terminal  9 . The support block  80  holds the holding portion  90  on the base portion  30  by injection molding. Referring to  FIG. 6  and  FIG. 7 , each terminal groove  78  further comprises a support block receiving groove  780 , each support block receiving groove  780  has a shallow groove  79  therein, the support block receiving grooves  780  are arranged side by side along the longitudinal direction and are communicated with each other. Each flat plate-shaped terminal  9  is inserted into each terminal groove  78  from down to up, the support block  80  of each flat plate-shaped terminal  9  is received in each support block receiving groove  780 , the interference protrusion  92  on the holding portion  90  of each flat plate-shaped terminal  9  is interference fixed with each shallow groove  79 . The support blocks  80  are arranged side by side along the longitudinal direction in the support block receiving grooves  780  which are communicated with each other. The material of each support block  80  is an electrically insulating material, so even if the support block receiving grooves  780  are communicated with each other to make the support blocks  80  to contact with each other, it does not have an adverse affect on the card edge connector  3 . However, in the embodiment, the holding portion  90  is separated from the base portion  30  of the flat terminal  9 , the present disclosure is not limited to this, in some embodiments, the card edge connector  3  does not comprise the support blocks  80  and the support block receiving grooves  780 , the holding portion  90  is integrally formed with the base portion  30  of the flat plate-shaped terminal  9 . 
     In addition, referring to  FIG. 3  and  FIG. 7 , the insulating housing  7  further comprises a plurality of terminal tail portion fixing grooves  76 . The terminal tail portion fixing groove  76  is configured to position and receive the tail portion  60  of the flat plate-shaped terminal  9 . Also, referring to  FIG. 3 , the card edge module  4  comprises a plurality of conductive pads  41 . After the card edge module  4  is inserted into the card edge inserting groove  74 , the conductive pads  41  are electrically connected with the contact portions  40  of the flat plate-shaped terminals  9 . 
     Features of some embodiments are summarized in above content, so that a person skilled in the art may better understand various aspects of the disclosed content of the present disclosure. A person skilled in the art of the present disclosure shall understand that the disclosed content of the present disclosure may be easily used to configure and design or modify other manufacturing approach or structure and in turn to realize the same object and/or attain the same advantage as the embodiments of the present disclosure. A person skilled in the art of the present disclosure shall also understand that, such an equivalent approach or structure cannot be departed from the spirit and scope of the disclosed content of the present disclosure, and a person skilled in the art may make various changes, substitutions and replacements, which are not departed from the spirit and scope of the disclosed content of the present disclosure.