The present invention relates to an electric connector.
Conventionally, in various electrical apparatuses, there has been widespread adoption of electric connectors each of which electrically connects a connecting object constituted by a signal transmission medium or the like such as a flexible flat cable (FFC) or a flexible printed circuit board (FPC) to a connected object such as a wiring board. This type of electric connector is for example mounted on a principal surface of the wiring board (connected object) for use, and the electric connector is provided with an insertion opening through which the signal transmission medium (connecting object) is inserted inward so that the signal transmission medium has its signal conducting path electrically connected to a signal conducting path of the wiring board through a contact member.
Meanwhile, in the field of recent electronics devices, electromagnetic interference caused by radiation of electromagnetic waves has presented a problem along with higher frequencies of transmission signals and increased frequency of operation, thus posing a risk, for example, of making electronics devices malfunctioning or unstable. Therefore, conventionally, the electric connector has been fitted with a conducting shell member covering an outer surface thereof, and the connecting object (signal transmission medium) has its ground conducting path electrically connected to a ground conducting path of the connected object (wiring board) via the shell member; furthermore, as can be seen from Japanese Unexamined Patent Application Publication No. 2014-225412 and Japanese Unexamined Patent Application Publication No.
2005-268018, after the connecting object (signal transmission medium) has been inserted into the electric connector, measures to enhance an electromagnetic shielding property are taken, for example, by operating an actuator having a shield member to bring a signal transmission line into a closed state or by entirely covering the electric connector with a conductive cover.
However, these conventional electric connectors work against improvement in productivity, as they require an additional operation or installation work to be carried out after the connecting object (signal transmission medium) has been inserted. Further, as for the electromagnetic shielding property, the risk of outward leak of electromagnetic waves is yet to be overcome and there is a need to further enhance electromagnetic compatibility.
The present inventor herein discloses Japanese Unexamined Patent Application Publication No. 2014-225412 and Japanese Unexamined Patent Application Publication No. 2005-268018 as examples of art related to the present invention.
It is therefore an object of the present invention to provide an electric connector designed to achieve satisfactory electromagnetic shielding of a signal transmission path without carrying out an additional operation.
In a first aspect of the present invention, in order to attain the foregoing object, an electric connector includes a contact member that electrically connects a signal transmission line of a connecting object to a signal conducting path of a connected object and a shell member electrically connects a ground transmission line of the connecting object to a ground conducting path of the connected object. In the electric connector, the shell member includes a first shell, disposed in a state of facing the connected object, that entirely covers the contact member and a second shell disposed to face the first shell and disposed between the connecting object and the connected object, and each of the first and second shells includes a connecting object ground contact point and a connected object ground contact point that are connected to the ground transmission line of the connecting object and the ground conducting path of the connected object, respectively.
According to the first aspect of the present invention thus configured, a ground path formed by the ground transmission line of the connecting object, the ground conducting path of the connected object, and the first shell of the shell member is disposed to cover one side of the contact member, and a ground path formed by the ground transmission line of the connecting object, the ground conducting path of the connected object, and the second shell of the shell member is disposed to cover the other side of the contact member, so that a signal transmission path formed by the contact member is in a state of being sandwiched by the ground path formed by the first shell and the ground path formed by the second shells. For this reason, satisfactory electromagnetic shielding of the signal transmission path is achieved by the ground paths.
In a second aspect of the present invention, it is desirable that the signal transmission line and the ground conducting path comprise a plurality of signal transmission lines and a plurality of ground conducting paths formed on the connecting object and the connected object, respectively, that the connecting object ground contact point and the connected object ground contact point comprise a plurality of connecting object ground contact points and a plurality of connected object ground contact points, respectively, provided at predetermined intervals in a direction of arrangement of the signal transmission lines and the ground conductive paths, and that the intervals between the connecting object ground contact points and the intervals between the connected object ground contact points be determined on the basis of frequencies of electric signals that are transmitted from the signal transmission lines.
The second aspect of the present invention thus configured makes it possible to, while achieving satisfactory electromagnetic shielding of the signal transmission path, appropriately adjust a contact pressure of the connection object ground contact points on the ground transmission line of the connecting object.
In a third aspect of the present invention, it is possible that the connecting object may be constituted by a flat-plate double-faced signal transmission medium with the ground transmission line formed on each of both surfaces of the signal transmission medium, that the connecting object ground contact point of the first shell may be connected to the ground transmission line formed on one of both surfaces of the signal transmission medium, and that the connecting object ground contact point of the second shell may be configured to be connected to the ground transmission line formed on the other one of both surfaces of the signal transmission medium.
In a fourth aspect of the present invention, it is possible that the signal transmission line of the connecting object may be disposed in a state of being sandwiched by the ground transmission lines provided on both surfaces of the connecting object.
In a fifth aspect of the present invention, it is possible that the connected object may be constituted by a wiring board, that the ground conducting path may be formed on each of both surfaces of the wiring board constituting the connecting object, and that the connected object ground contact points of the first and second shells may be connected to the ground conducting path formed on one of both surfaces of the wiring board.
In a sixth aspect of the present invention, it is possible that the signal conducting path of the wiring board may be disposed in a state of being sandwiched between the ground conducting paths provided on both surfaces of the wiring board.
In a seventh aspect of the present invention, it is desirable that the first shell be provided with an opening, provided in a position facing a part where the contact member is connected to the connected object, through which a connected part of the contact member is able to be seen.
The seventh aspect of the present invention thus configured makes it possible visually confirm, through the opening of the first shell, a state of the connected part of the contact member with the connected object.
In an eighth aspect of the present invention, it is possible to further include a lock member that holds the signal transmission medium constituting the connecting object.
As mentioned above, an electric connector according to the present invention is configured such that a shell member that is ground-connected to a connected object is constituted by a first shell that entirely covers a contact member in a state of facing the connected object and a second shell that faces the first shell in a part between a connecting object and the connected object, that each of those first and second shells is provided with a connecting object ground contact point and a connected object ground contact point that are connected to a ground transmission line of the connecting object and a ground conducting path of the connected object, respectively, that a signal transmission path formed by the contact member is in a state of being sandwiched between a ground path formed by the first shell and a ground path formed by the second shell, whereby satisfactory electromagnetic shielding of the signal transmission path is achieved by the ground paths. This makes it possible to achieve satisfactory electromagnetic shielding of the signal transmission path without carrying out an additional operation.
In the following, embodiments in which the present invention is applied to receptacle connectors that are mounted on wiring boards of various types of electronics device are described in detail with reference to the drawings.
A receptacle connector 1 shown in
The following assumes that the principal surface of the aforementioned wiring board WB extends horizontally, that a direction orthogonal to the principal surface of the wiring board WB is a “connector height direction”, and that directions away from and toward the principal surface of the wiring board WB in the “connector height direction” are an “upward direction” and a “downward direction”, respectively. Further, assuming that a direction of elongated extension of the housing 11 is a “connector longitudinal direction”, a direction orthogonal to both the “connector longitudinal direction” and the “connector height direction” is called a “connector width direction”.
The aforementioned housing 11 has an insertion opening 11a, formed in one end face thereof in the “connector width direction” so as to form an elongated slit shape along the “connector longitudinal direction”, into which a signal transmission PB serving as a flat-plate “connecting object” such as a flexible flat cable (FFC) or a flexible printed circuit board (FPC) described below is inserted. Note here that the signal transmission medium (such as an FFC or an FPC) PB and the wiring board WB are equivalent to the “connecting object” and the “connected object”, respectively, in the present invention.
Further, of those end faces which form an outer circumferential surface of the housing 11, the end face provided with the aforementioned insertion opening 11a is hereinafter called a “front end face” and the end face opposite in the “connector width direction” to the “front end face” is hereinafter called a “back end face”. Moreover, the signal transmission medium (connecting object) PB has its terminal area inserted from the “front” toward the “back” of the insertion opening 11a, and the terminal area of the signal transmission medium PB inserted through the insertion opening 11a is accommodated in the interior of a hollow medium insertion passage 11b provided in the housing 11 so as to extend from the insertion opening 11a toward the “back”.
Meanwhile, to the aforementioned housing 11, a plurality of conductive contacts (conductive terminals) 13 serving as contact members are attached in a state of being arranged at predetermined pitch distances along the “connector longitudinal direction” of the housing 11. These conductive contacts 13 are each constituted by a metal member formed by bending into the desired shape and, as will be described next, are each provided with a signal contact 13a disposed to stretch out into the aforementioned medium insertion passage 11b.
More specifically, each conductive contact (conductive terminal) 13 is disposed to extend in the “connector width direction” and has a fixing base 13b, fixed in the back end of the aforementioned housing 11 in a state of extending substantially horizontally, that constitutes a substantially central part of the conductive contact 13 in a direction of extension (connector width direction). A part extending from the fixing base 13b toward the “back” is bent at a substantially right angle toward a “lower position” immediately after projecting outward from the back end face of the housing 11. Moreover, the back end of the conductive contact 13 that extends downward reaches a principal surface of the aforementioned wiring board (connected object) WB, is again bent substantially horizontally toward the “back”, and then extends horizontally substantially, and the substantially horizontally extending part forms a signal connection terminal 13c. The signal connection terminal 13c is designed to be soldered to a signal conducting path WB1 (see
It should be noted that, as shown especially in
Further, a part of each of the conductive contacts (conductive terminals) 13 that extends from the fixing base 13b to the “front” forms a movable beam 13d that extends in a cantilever manner toward the inside of the aforementioned medium insertion passage 11b. The movable beam 13d is formed to be elastically displaceable up and down, centered at a junction with the fixing base 13b disposed in the back of the movable beam 13d. Moreover, at the leading end of the movable beam 13d in a direction of extension, the aforementioned signal contact 13a is provided in a state of projecting downward in a mountain shape and configured to reciprocate up and down along with the elastic displacement of the movable beam 13d (see
The signal contact 13a of this conductive contact (conductive terminal) 13 is formed in such a layout relationship as to make contact from above with the signal transmission medium (connecting object) PB inserted in the medium insertion passage 11b as mentioned above, and such a contact relationship allows the conductive contact 13 to be electrically connected to the signal transmission medium PB so that a signal transmission path is formed (see
That is, as shown especially in
Meanwhile, each of the aforementioned plurality of conductive contacts (conductive terminals) 13 is disposed in a position corresponding to the corresponding one of the plurality of signal transmission lines (signal lines) PB1 arranged in the plate width direction (connector longitudinal direction) of the signal transmission medium (connecting object) PB. Moreover, in a state of completion of insertion of the signal transmission medium PB into the medium insertion passage 11b, each of the signal transmission lines PB1 exposed at a surface part (i.e. an upper surface part of
Moreover, an electrical connection relationship with each of the conductive contacts (conductive terminals) 13 allows the signal transmission lines (signal lines) PB1 of the signal transmission medium (connecting object) PB to be connected to the signal conducting paths WB1 of the wiring board (connected object) WB via the conductive contacts 13, whereby a “signal transmission path” leading from the signal transmission medium PB to the wiring board WB is formed.
Further, in the terminal area of such a signal transmission medium (connecting object) PB, parts of the upper ground transmission lines PB2 that are closer to the back side (i.e. the left side of
The shell member 12 fitted so as to cover the outer surface of the housing 11 as mentioned above is constituted by a body obtained by bending a thin metallic member, and is constituted by an upper shell 12a serving as a first shell that covers an upper part of the housing 11 and a lower shell 12b serving as a second shell that covers a lower part of the housing 11. The shell member 12, constituted by the upper shell (first shell) 12a and the lower shell (second shell) 12b, is configured to electrically connect the upper ground transmission lines (shield lines) PB1 and the lower ground transmission lines (shield lines) PB3 of the aforementioned signal transmission medium (connecting object) PB to the upper ground conducting paths WB2 formed on the principal surface (i.e. the upper surface of
That is, the upper shell (first shell) 12a of the shell member 12 is disposed in a state of entirely covering the conductive contacts (conductive terminals) 13 from above by covering the upper surface of the housing 11 as mentioned above. The upper shell 12a has its back end edge (i.e. the left end of
Each of the plurality of these upper shell backward ground connections (connected object ground contact points) 12a1 is provided in correspondence with the plurality of upper ground conducting paths WB2 formed on the principal surface (i.e. the upper surface of
Further, at the front end edge (i.e. the left end of
That is, each of the upper shell forward ground connections (connecting object ground contact points) 12a2 provide at the front end edge of the upper shell (first shell) 12a as mentioned above is disposed in a position corresponding to the corresponding one of the upper ground transmission lines (shield lines) PB2 disposed in the terminal area of the aforementioned signal transmission medium (connecting object) PB, and is formed in such a layout relationship as to elastically make contact from above with the upper ground transmission lines PB2 of the signal transmission medium PB inserted in the medium insertion passage lib. Moreover, such a contact relationship allows the upper shell forward ground connections 12a2 of the upper shell 12a to be electrically connected to the upper ground transmission lines PB2 of the signal transmission medium PB.
Thus, the upper shell (first shell) 12a has the upper shell backward ground connections (connected object ground contact points) 12a1, which are connected to the upper ground conducting paths WB2 provided on the principal surface (upper surface) of the wiring board (connected object) WB, and includes the upper shell forward ground connections (connecting object ground contact points) 12a2, which are connected to the upper ground transmission lines PB2 provided on the upper surface of the signal transmission medium (connecting object) PB. Moreover, an electrical connection relationship between these parts allows an “upper ground transmission path” to be formed to lead from the upper ground transmission lines PB2 of the signal transmission medium PB to the upper ground conducting paths WB2 of the wiring board WB via the upper shell 12a.
Note here that the intervals between the upper shell forward ground connections (connecting object ground contact points) 12a2 of the upper shell (first shell) 12a mentioned above are determined on the basis of the frequency of an electric signal that is transmitted from a signal conducting path including the conductive contacts (conductive terminals) 13 so that sufficient electromagnetic shielding can be achieved against the electric signal. Specifically, the intervals between the upper shell forward ground connections 12a2 are set so that there is no gap that is equal to or larger than 1/20 of the wavelength of the electric signal.
By thus configuring, in appropriate conditions, the intervals between which the upper shell forward ground connections 12a2 are placed and the number of upper shell forward ground connections 12a2 that are installed, it is made possible to, while achieving satisfactory electromagnetic shielding of the signal transmission path, appropriately adjust a contact pressure of the upper shell forward ground connections 12a2 on the upper ground transmission lines (shield lines) PB2 disposed in the terminal area of the signal transmission medium (connecting object) PB.
Further, the lower shell (second shell) 12b of the aforementioned shell member 12 is attached to a bottom surface part of the housing 11, and is formed from a plate member disposed in a state of constituting a lower surface of the aforementioned medium insertion passage 11b. That is, this lower shell 12b is fitted in a state of facing the aforementioned upper shell (first shell) 12a from below across the conductive contacts (conductive terminals) 13, and is formed in such a layout relationship as to make contact from below with the lower ground transmission lines (shield lines) PB3 constituting the lower surface of the signal transmission medium (connecting object) PB inserted in the medium insertion passage 11b.
More specifically, this lower shell (second shell) 12b is provided with a plurality of shell springs 12b1 placed at predetermined intervals in the “connector longitudinal direction”. Each of those shell springs 12b1 is formed by cutting and raising a part of the lower shell 12b, and extends in a cantilever manner backward from the front end of the lower shell 12b. Provided at the back end (i.e. the right end of
Each of those shell spring ground contact points 12b2 is disposed in a position corresponding to the lower ground transmission lines (shield lines) PB3 provided on the lower surface of the signal transmission medium (connecting object) PB, and is designed to be brought into a ground connection state by making contact from below with the lower ground transmission lines PB3 of the signal transmission medium PB inserted in the medium insertion passage 11b.
Furthermore, the back end (i.e. the right end of
Further, at the back end (i.e. the left end of
Thus, the lower shell (second shell) 12b includes the shell spring ground contact points (connecting object ground contact points) 12b2, which are connected to the lower ground transmission lines (shield lines) PB3 provided on the lower surface of the signal transmission medium (connecting object) PB, and includes the lower shell backward ground connections (connected object ground contact points) 12b3, which are connected to the upper ground conducting paths WB2 provided on the principal surface (upper surface) of the wiring board (connected object) WB. Moreover, an electrical connection relationship between these parts allows a “lower ground transmission path” to be formed to lead from the lower ground transmission lines PB3 of the signal transmission medium PB to the upper ground conducting paths WB2 of the wiring board WB via the lower shell 12b.
Note here that the intervals between the shell springs 12b1 of the lower shell (second shell) 12b mentioned above and the shell spring ground contact points (connecting object ground contact points) 12b2 of those shell springs 12b1 are determined on the basis of the frequency of an electric signal that is transmitted from a signal conducting path including the conductive contacts (conductive terminals) 13 so that sufficient electromagnetic shielding can be achieved against the electric signal. Specifically, the intervals between the upper shell forward ground connections 12a2 are set so that there is no gap that is equal to or larger than 1/20 of the wavelength of the electric signal.
By thus configuring, in appropriate conditions, the intervals between which the shell spring ground contact points 12b2 are placed and the number of shell spring ground contact points 12b2 that are installed, it is made possible to, while achieving satisfactory electromagnetic shielding of the signal transmission path, appropriately adjust a contact pressure of the shell spring ground contact points 12b2 on the lower ground transmission lines (shield lines) PB3 disposed in the terminal area of the signal transmission medium (connecting object) PB.
Further, as mentioned above, the upper ground conducting paths WB2 are formed on the principal surface (upper surface) of the wiring board (connected object) WB, and as shown especially in
According to the present embodiment thus configured, as shown especially in
As a result, a “signal transmission path (PB1-13a-13-13c-WB1)” formed between the signal transmission medium PB and the wiring board WB via the conductive contacts 13 is in a state of being sandwiched between the aforementioned “upper ground transmission path” and “lower ground transmission path”, formed between the signal transmission medium PB and the wiring board WB, via the upper shell (first shell) 12a and the lower shell (second shell) 12b, and those upper and lower ground transmission paths allow satisfactory electromagnetic shielding of the signal transmission path.
Meanwhile, a pair of lock members 14 formed integrally with the upper shell 12a and the lower shell 12b are provided at both ends of the aforementioned upper shell (first shell) 12a and lower shell (second shell) 12b in the “connector longitudinal direction”. Each of those lock members 14 has a cantilever movable plate 14a that elastically swings up and down, and each of those movable plates 14a is provided with a locking nail (not illustrated) that engages with the signal transmission medium (connecting object) PB inserted in the aforementioned medium insertion passage lib (see
Meanwhile, in the terminal area of the signal transmission medium (connecting object) PB, as shown especially in
The invention made by the present inventor has been described above in concrete terms on the basis of embodiments. However, the invention is not limited to the aforementioned embodiments and can of course be modified in various ways without departing from the scope of the invention.
For example, although, in each of the aforementioned embodiments, the upper shell (first shell) 12a is configured to form an integral cover shape that covers the entire length of the conductive contacts (contact members) 13 serving as contact members, the upper shell 12a can also be configured to be partially openable. As shown in
Adopting such a configuration makes it possible to expose the signal connection terminals 13c of the conductive contacts (contact members) 13 outward in a step preceding soldering of the back end of the upper shell (first shell) 12a, and the state of connection of the conductive contacts 13 with the wiring board (connected object) WB becomes visually confirmable from above through the opening of the upper shell 12a, whereby manufacturing quality can be improved.
Further, although each of the aforementioned embodiments is one obtained by applying the present invention to a horizontal-insertion electric connector, the present invention is not limited to it but may also be similarly applied to a vertical-insertion electric connector.
Furthermore, an electric connector according to the present invention is not limited to one which is used to connect a flexible flat cable (FFC) or a flexible printed circuit board (FPC) as in the aforementioned embodiment, and the present invention can also be similarly applied to a wide variety of electric connectors that electrically connect a substrate to a substrate or a cable to a substrate.
As noted above, the present invention is widely applicable to a wide variety of electric connectors that are used in electrical apparatuses.
Number | Date | Country | Kind |
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2017-243811 | Dec 2017 | JP | national |