JP2011204599A - Socket for memory card - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a socket for a memory card enabling a reliable data transmission while increasing a speed of the data transmission.SOLUTION: The socket for the memory card includes a metal shell 5 formed into a square cylinder with a card insertion slot opening on a front surface where the memory card is inserted and removed, and a contact block 12 in which a plurality of contacts 3 respectively contactable with a plurality of I/O contact surfaces arranged on one surface of the memory card are held by a holding portion 13 made of an insulating synthetic resin and attached into a rear part of the metal shell 5, wherein a terminal part 3c provided on one end side of each contact 3 of the contact block 12 to be joined to a conductive pattern for a signal formed on a wiring board as a mounting section is led out of the rear part of the metal shell 5, and the metal shell 5 is provided with three board connecting portions 40 electrically connectable by joining to the conductive pattern forming a stable potential of the wiring board.

Description

  The present invention relates to a memory card socket for detachably connecting a memory card such as an SD memory card (registered trademark).

  Conventionally, a memory card such as an SD memory card (registered trademark) has been widely used in various digital devices (for example, a digital camera and a digital video camera). In recent years, in order to read and write large-capacity contents such as high-definition still images and moving images in these memory cards, it is required to further increase the capacity of the memory cards and to increase the speed of data transmission.

  For example, as shown in FIG. 27, the memory card socket for detachably connecting such a memory card is formed of a stainless steel metal plate and positioned on the wiring board side on which the memory card socket is mounted. The lower shell (base shell) 1 and the lower shell 1 are formed of a stainless steel metal plate, and are attached to one surface side of the lower shell 1 to open the card insertion slot 5a on the front surface. An upper shell (cover shell) 2 comprising a rectangular metal shell 5 and a lower shell 1 and a plurality of I / O contact surfaces (not shown) arranged in parallel on one surface of the memory card. A plurality of contactable (9 in the illustrated example) contacts 3 are held by a holding portion 13 made of an insulating synthetic resin, and a contact block 12 mounted in the rear portion of the metal shell 5, and a metal On the front side of the shell 5, it protrudes continuously and integrally on the side of the wiring board (not shown) on which the memory card socket is mounted from both lateral edges perpendicular to the memory card insertion / removal direction in the lower shell 1. The thing provided with the two connection parts 4 is proposed (for example, refer patent document 1). The connecting portion 4 is inserted into a holding hole (not shown) provided in the wiring board and is electrically connected to the ground of the wiring board.

JP 2009-16313 A

  By the way, in order to increase the data transmission speed of the memory card, it is conceivable to increase the data transmission clock frequency. However, if the data transmission clock frequency is increased, the harmonic component of the clock frequency will affect the data transmission. The generated noise tends to increase. Therefore, a read error or a write error may occur during the operation of the memory card, and stable data transmission may not be possible.

  The memory card socket described above can release noise generated during data transmission of the memory card to the ground of the wiring board from each connection portion 4 that is continuously and integrally provided on the lower shell 1. However, even in the memory card socket described above, noise tends to increase as the capacity of the memory card increases and the data transmission speed increases.

  The present invention has been made in view of the above-mentioned reasons, and an object thereof is to provide a memory card socket that enables stable data transmission while achieving high-speed data transmission.

  The memory card socket according to the present invention is formed in a rectangular tube shape having a card insertion opening on the front surface, a metal shell into which the memory card is inserted and removed, and a plurality of I / Os arranged in parallel on one surface of the memory card. A plurality of contacts that can contact each contact surface is held by a holding portion made of an insulating synthetic resin, and a contact block mounted in a rear portion of the metal shell, and each contact of the contact block A terminal part provided on one end side and joined to a signal conductive pattern formed on a wiring board to be mounted is a memory card socket led out from the rear part of the metal shell, It is characterized in that there are provided at least three board connection portions that can be joined and electrically connected to a conductive pattern that has a stable potential of the wiring board.

  In this memory card socket, it is preferable that the board connecting portion is provided at a corner of the metal shell.

  In this memory card socket, it is preferable that at least one of the substrate connection portions is provided at a central portion of one surface of the metal shell that is a surface facing the wiring substrate.

  In this memory card socket, it is preferable that the board connecting portion is provided at two corners on the front side of the metal shell and one corner on the rear side of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is provided in the vicinity of two corners on the front side of the metal shell and the rear edge of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is provided at two corners on the front side of the metal shell and at a central portion of one surface of the metal shell facing the wiring board. .

  In this memory card socket, it is preferable that the board connecting portion is provided in the vicinity of the two corners on the rear side of the metal shell and the front edge of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is provided at two corners on the rear side of the metal shell and at a central portion of one surface of the metal shell facing the wiring board.

  In this memory card socket, it is preferable that the board connecting portion is provided at four corners of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is a cut-and-raised piece formed by cutting and raising a part of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is a protrusion formed by squeezing a part of the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is a conductor layer formed by depositing a metal film on a part of the metal shell.

  In this memory card socket, the cut-and-raised piece is orthogonal to the insertion / extraction direction of the memory card and the horizontal direction of the metal shell from the metal shell at the side surface in the horizontal direction orthogonal to the insertion / extraction direction of the memory card in the metal shell. It is preferable that it is extended in the direction.

  In the memory card socket, the metal shell is formed of a first metal plate, and is formed of a lower shell positioned on the wiring board side and a second metal plate, and is formed on one surface side of the lower shell. It is preferable that the upper and lower shells are attached, and the cut-and-raised pieces protrude rearward.

  In this memory card socket, it is preferable that the cut and raised pieces are provided so as to protrude from both sides in the left-right direction of the metal shell.

  In this memory card socket, it is preferable that the cut-and-raised piece projects from the vicinity of the rear edge of the upper shell.

  In this memory card socket, it is preferable that the cut-and-raised piece protrudes from both side edges in the left-right direction perpendicular to the insertion / extraction direction of the memory card in the upper shell.

  In this memory card socket, it is preferable that the protrusion is formed at a corner of one surface of the metal shell that faces the wiring board.

  In this memory card socket, it is preferable that the board connecting portion is a terminal piece connected to the metal shell and protrudes rearward of the metal shell.

  In this memory card socket, the board connection portion is a terminal piece connected to both side portions of the metal shell, and protrudes in a direction orthogonal to the insertion / extraction direction of the memory card and the left-right direction of the metal shell. It is preferable that

  In this memory card socket, it is preferable that the board connecting portion is formed by welding or bonding to the metal shell.

  In this memory card socket, it is preferable that the board connecting portion is formed in pressure contact with both lateral sides of the metal shell.

  In this memory card socket, it is preferable that the board connection portion is formed by being fitted to a fitting portion of the metal shell.

  The socket for a memory card according to the present invention has an effect that stable data transmission can be achieved while speeding up data transmission.

The socket for memory cards of this embodiment is shown, (a) is the perspective view seen from the surface side, (b) is the perspective view seen from the back surface side. (A) is a principal part perspective view of the memory card socket same as the above, (b) is a principal part perspective view of another structural example. (A) is a principal part perspective view of the memory card socket same as the above, (b) is a principal part perspective view of another structural example. (A) is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above, (b) is a schematic plan view which shows the other example of arrangement | positioning. (A) is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above, (b) is a schematic plan view which shows the other example of arrangement | positioning. (A) is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above, (b) is a schematic plan view which shows the other example of arrangement | positioning. It is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above. It is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above. It is a schematic plan view which shows the example of arrangement | positioning of the board | substrate connection part of the socket for memory cards same as the above. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. It is a top view which shows the other structural example of the socket for memory cards same as the above. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) and (c) are principal part enlarged views. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) and (c) are principal part enlarged views. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) and (c) are principal part enlarged views. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) is a principal part enlarged view. The other example of a structure of the socket for memory cards same as the above is shown, (a) is a perspective view, (b) and (c) are principal part enlarged views. It is a perspective view which shows the other structural example of the socket for memory cards same as the above. It is a distribution diagram of the noise voltage when a sine wave signal is input to the contact of the socket for memory card same as above. It is another distribution map of the noise voltage at the time of inputting a sine wave signal to the contact of the socket for memory cards same as the above. The memory card socket of a prior art example is shown, (a) is the perspective view seen from the surface side, (b) is the perspective view seen from the back surface side.

  The memory card socket of this embodiment will be described with reference to FIGS.

  As shown in FIG. 1, the memory card socket of the present embodiment is formed in a rectangular tube shape with a card insertion opening opened on the front surface (upper right in FIG. 1), and a metal shell 5 into which a memory card is inserted and removed. In addition, a plurality of (9 in the illustrated example) contacts 3 that can individually contact a plurality of I / O contact surfaces (not shown) arranged on one surface of the memory card are made of an insulating synthetic resin. A contact block 12 held by a holding portion 13 and mounted in a rear portion (lower left in FIG. 1) of the metal shell 5. The metal shell 5 has a wiring board to be mounted on which a memory card socket is mounted. Three substrate connection portions 40 are provided which can be joined and electrically connected to a ground (conductive pattern having a stable potential) of a ground (not shown). In addition, although the three board connection parts 40 are provided in the metal shell 5, the number of the board connection parts 40 should just be three or more.

  As shown in FIG. 1 (b), the contacts 3 are spaced apart from each other in the left-right direction of the metal shell 5 (direction perpendicular to the memory card insertion / removal direction), and a metal film is deposited on one end side. Each contact piece 3b that contacts the formed I / O contact surface is formed, and each terminal portion 3c that can be connected to a signal conductive pattern (not shown) formed on the wiring board on the other end side is made of metal. It is led forward from the rear part of the shell 5. Each contact 3 is made of, for example, a copper alloy.

  As shown in FIG. 1 (b), the board connecting portion 40 has memory card sockets from both sides in the left-right direction of the metal shell 5 on the front side of the metal shell 5 (upper right side in FIG. 1 (b)). One tip is provided on the wiring board side to be mounted (on the upper surface side in FIG. 1B), and the tip of each contact piece 3b of each contact 3 on one surface of the metal shell 5 facing the wiring board. One is disposed at the center of the memory card socket on the card insertion slot side (upper right side in FIG. 1B).

  As shown in FIG. 3A, the shape of the board connecting portion 40 is provided so as to protrude from the lateral side surface of the lower shell 1 in a direction perpendicular to the left and right direction, and is provided in the holding hole (see FIG. (Not shown) and can be electrically connected by bonding to the ground of the wiring board. Here, the board connecting portion 40 is not limited to the example of FIG. 3A, but protrudes from the side surface of the lower shell 1 to the outer side in the left-right direction of the lower shell 1 as shown in FIG. 3B, for example. It may be electrically connected by bonding to a conductive pattern (ground) which is provided on one surface of the wiring board on the lower shell 1 side and has a stable potential of the wiring board.

  As shown in FIG. 2A, the metal shell 5 is formed by bending a stainless metal plate (first metal plate), and the lower shell 1 positioned on the wiring board side, Like the shell 1, the upper shell 2 is formed by bending a stainless steel metal plate (second metal plate) and is attached to one surface side of the lower shell 1. Here, the lower shell 1 has a U-shaped cross section perpendicular to the front-rear direction of the metal shell 5, the upper shell 2 is formed in a rectangular plate shape, and the butted portion between the lower shell 1 and the upper shell 2 (Abutting portion between the leading edge of the side wall of the U-shaped lower shell 1 and the end in the left-right direction of the rectangular plate-shaped upper shell 2) 14a is joined by laser welding. Therefore, the lower shell 1 and the upper shell 2 have the same potential. That is, each board connection portion 40 that is continuously and integrally projected from the lower shell 1 to the wiring board side is inserted into the holding hole provided in the wiring board, and each board connection portion 40 is connected to the ground of the wiring board. And the metal shell 5 composed of the lower shell 1 and the upper shell 2 is grounded to the ground of the wiring board. As a result, static electricity and external noise to each contact 3 can be prevented, and radiation noise from each contact 3 to the outside can be reduced. Here, the shape of the lower shell 1 and the upper shell 2 is not limited to the shape illustrated in FIG. 2A, and for example, as shown in FIG. 2B, both are orthogonal to the front-rear direction of the metal shell 5. The cross-section of the lower shell 1 and the upper shell 2 is a butted portion (the end edge of the side wall of the U-shaped lower shell 1 and the end edge of the side wall of the U-shaped upper shell 2) The part 14b may be joined by laser welding.

  As another example of arrangement of the board connection part 40 of the memory card socket, there are examples shown in FIGS.

  In the example shown in FIG. 4 (a), the board connecting portions 40 are arranged on the front side of the metal shell 5 (the lower side in plan view in FIG. 4), respectively, in the left and right ends of the metal shell 5 in the lower shell 1. One is arranged in the vicinity of the rear edge of the lower shell 1 on the rear side of the metal shell 5 (upper side in FIG. 4 in plan view).

  Further, in the example shown in FIG. 4B, one board connecting portion 40 is disposed near the front edge of the lower shell 1 on the front side of the metal shell 5, and on the rear side of the metal shell 5. One is arranged at each of the left and right ends of the lower shell 1. Therefore, since the board connecting portion 40 is disposed so as to surround the central portion of the lower shell 1, for example, noise generated from a portion that can be a noise source such as a control IC built in the memory card is generated for each board. It becomes easy to escape from the connection part 40 to the ground of the wiring board.

  In the example shown in FIG. 5A, one board connecting portion 40 is disposed at each of the corners of the metal shell 5 on the front side of the metal shell 5, and the metal shell 5 on the rear side of the metal shell 5. One is disposed at one corner.

  Further, in the example shown in FIG. 5B, one board connecting portion 40 is arranged at one corner of the metal shell 5 on the front side of the metal shell 5, and the metal is connected on the rear side of the metal shell 5. One is disposed at each corner of the shell 5. Here, only the lower shell 1 is provided by providing each substrate connecting portion 40 at the corner of the metal shell 5 as in the arrangement example of the substrate connecting portion 40 illustrated in FIGS. 5A and 5B. Instead, for example, by providing the board connecting portion 40 that continuously and integrally protrudes from the upper shell 2 to the wiring board side, the upper shell 2 can also be joined and electrically connected to the ground of the wiring board. Further, by attaching a metal film functioning as a heat radiating portion to the central portion of the lower shell 1 on the wiring board side, it is possible to improve the heat radiating property of the heat generated during the operation of the memory card. It is also possible to dispose a heat radiating component at the center of the lower shell 1.

  In the example shown in FIG. 6A, one board connecting portion 40 is provided at the central portion of one surface of the lower shell 1 that faces the wiring board, and the metal shell 5 is provided on the front side of the metal shell 5. One is arranged at each corner.

  Further, in the example shown in FIG. 6B, one board connection portion 40 is disposed at each of the corners of the metal shell 5 on the rear side of the metal shell 5, and One is arranged at the center. Here, as in the arrangement example of the board connecting portions 40 illustrated in FIGS. 6A and 6B, by providing one board connecting portion 40 at the central portion of the one surface in the lower shell 1. For example, noise generated from the control IC built in the memory card can be released to the ground of the wiring board from the board connecting part 40 provided in the central part of the one surface of the lower shell 1. Therefore, noise generated during data transmission can be suppressed.

  In the example shown in FIG. 7, one board connecting portion 40 is provided at each of the corners of the metal shell 5 on the front side of the metal shell 5, and one board connection portion 40 is provided near the rear edge of the lower shell 1. It is arranged.

  Further, in the example shown in FIG. 8, one board connecting portion 40 is disposed at each corner of the metal shell 5 on the rear side of the metal shell 5, and one substrate connecting portion 40 is disposed near the front edge of the metal shell 5. It is set up. Therefore, since the board connecting portion 40 is disposed so as to surround the central portion of the metal shell 5, for example, noise generated from a portion that can be a noise source such as a control IC built in the memory card is connected to each board. It becomes easy to escape from the portion 40 to the ground of the wiring board.

  In the example shown in FIG. 9, the board connecting portion 40 is disposed at four corners of the metal shell 5. Therefore, for example, noise generated from a portion that can be a noise source such as a control IC built in the memory card is more easily released to the ground of the wiring board than in FIG.

  Moreover, as another shape of the board | substrate connection part 40 of the socket for memory cards, there exists an example shown, for example in FIGS.

  Each board connecting portion 40 in FIG. 10 is a cut-and-raised piece formed by cutting and raising the metal shell 5, and the cut-and-raised piece extends from the lateral side surface of the metal shell 5 to the wiring board side. It is set up.

  Further, each substrate connecting portion 40 which is a cut and raised piece in FIG. 11 protrudes rearward (lower left in FIG. 11) from the rear end edge of the lower shell 1, and the front end portion of the protruding substrate connecting portion 40 is provided. Is bent toward the wiring board. Here, since the board connecting portion 40 which is the cut-and-raised piece illustrated in FIGS. 10 and 11 is formed by cutting and raising the metal shell 5, it is easy to form the board connecting portion 40. Therefore, the cost can be reduced. Further, the board connecting portion 40 which is a cut and raised piece is inserted into the holding hole of the wiring board, and a conductive pattern (ground) having a stable potential formed on the inner peripheral surface of the holding hole of the wiring board with solder. The bonding strength can be increased by bonding to.

  Each board connecting portion 40 that is a cut and raised piece in FIG. 12 protrudes rearward from the rear edge of the lower shell 1. Therefore, each board connection part 40 can be joined to the conductive pattern that is a stable potential of the wiring board formed on one surface of the wiring board by soldering or the like, like the terminal parts 3c.

  Each board connection portion 40 which is a cut-and-raised piece in FIG. 13 protrudes from the rear edge of the upper shell 2 to the wiring board side on the rear side of the metal shell 5. Therefore, each board connection portion 40 is inserted into the holding hole of the wiring board and joined to a conductive pattern (ground) having a stable potential formed on the inner peripheral surface of the holding hole of the wiring board with solder. Thus, the upper shell 2 can be electrically connected to the ground of the wiring board.

  Each board connection part 40 which is a cut-and-raised piece in FIG. 14 protrudes from the rear edge of the upper shell 2 to the wiring board side on the rear side of the metal shell 5, and the tip part of the board connection part 40 thus provided protrudes. It is bent backwards. Therefore, each board connection portion 40 can be joined to the conductive pattern that is a stable potential of the wiring board formed on one surface of the wiring board by solder or the like, similarly to the terminal portions 3c, and the upper shell 2 Can be electrically connected to the ground of the wiring board.

  Each board connection portion 40 which is a cut-and-raised piece in FIG. 15 protrudes from the lateral edge of the metal shell 5 in the upper shell 2 to the wiring board side on the rear side of the metal shell 5. Therefore, each board connection portion 40 is inserted into the holding hole of the wiring board and joined to a conductive pattern (ground) having a stable potential formed on the inner peripheral surface of the holding hole of the wiring board with solder. Thus, the upper shell 2 can be electrically connected to the ground of the wiring board. Moreover, since each board | substrate connection part 40 exists in the position away from each terminal part 3c rather than FIG. 13, joining by solder etc. becomes easy.

  Each board connection part 40 which is a cut-and-raised piece in FIG. 16 is formed by raising and lowering the side part of the lower shell 1 in the left-right direction (the left-right direction of the metal shell 5 in the lower shell 1). Projecting from the side surface portion to the wiring board side. Therefore, each board connection portion 40 is inserted into the holding hole of the wiring board and joined to a conductive pattern (ground) having a stable potential formed on the inner peripheral surface of the holding hole of the wiring board with solder. Thus, the lower shell 1 can be electrically connected to the ground of the wiring board.

  Each board connection portion 40 in FIG. 17 is a protrusion formed by squeezing one surface of the lower shell 1 which is a surface facing the wiring board. Here, in the memory card socket illustrated in FIG. 17, the board connection portion 40, which is a protrusion, is inserted into the holding hole provided in the wiring board, and the board connection portion 40 is grounded by soldering. Since the holding hole provided in the wiring board is closed by the board connecting portion 40 when joining to the solder, the solder flux from the one surface side of the wiring board opposite to the lower shell 1 to the lower shell 1 side Can be prevented, and the mounting strength on the wiring board can be increased.

  Each substrate connecting portion 40 in FIG. 18 is a conductor layer formed by depositing a metal film on a part of one surface of the lower shell 1 that is a surface facing the wiring substrate. Here, the memory card socket illustrated in FIG. 18 can improve the heat dissipation of the heat generated during the operation of the memory card by providing the board connection portion 40 which is a conductor layer that functions as a heat dissipation portion. The mounting strength on the wiring board can be increased.

  Each board connecting portion 40 in FIG. 19 is a terminal piece connected to a connecting piece 1r protruding from the rear end edge of the lower shell 1 on the rear side of the metal shell 5, and the connected terminal piece is the above-mentioned terminal piece. It protrudes to the wiring board side. Therefore, it is possible to connect each board | substrate connection part 40 to the connection piece 1r which protruded from the rear-end edge of the lower shell 1 in the rear part side of the metal shell 5. FIG.

  Each board connection part 40 in FIG. 20 is a terminal piece connected to both sides in the left-right direction of the lower shell 1, and the connected terminal piece protrudes toward the wiring board side. Therefore, it is possible to connect each board | substrate connection part 40 to the both sides of the left-right direction of the lower shell 1. FIG.

  Each board connection part 40 in FIG. 21 is a terminal piece formed by bonding to the lateral side part of the lower shell 1 on the rear side of the metal shell 5 by welding or a conductive adhesive. Therefore, it is possible to bond each substrate connecting portion 40 to the lateral side portion of the lower shell 1 on the rear side of the metal shell 5 by welding or a conductive adhesive.

  Each substrate connecting portion 40 in FIG. 22 is a terminal piece formed by being pressed against pressure contact portions 1p provided on both sides in the left-right direction of the lower shell 1 on the rear side of the metal shell 5. Therefore, it is possible to press-contact each board connection part 40 on the to-be-contacted part 1p provided on the both sides in the left-right direction of the lower shell 1 on the rear side of the metal shell 5.

  Each board connection part 40 in FIG. 23 is a fitting part formed by fitting to a fitted part 1q provided on the side part in the left-right direction of the lower shell 1 on the rear side of the metal shell 5. Therefore, it is possible to fit each board connection part 40 to the to-be-fitted part 1q provided in the side part of the left-right direction of the lower shell 1 on the rear side of the metal shell 5.

  Here, regarding the memory card socket as shown in FIG. 10 described above, the results of measuring the distribution of the noise voltage in the metal shell 5 are shown in FIGS. Here, as a method of measuring the distribution of the noise voltage in the metal shell 5, a sine wave signal (for example, for example, is applied to the contact 3 of the memory card socket with the SD memory card inserted into the memory card socket. The frequency of 100 MHz was input, and the distribution of noise voltage was measured with the metal shell 5 and the antenna that detects the electromagnetic field generated around the metal shell 5. Further, the memory card socket is arranged at the position of the alternate long and short dash line shown in FIGS.

  FIG. 25 shows the distribution of noise voltage when each board connection portion 40 is not grounded to the ground of the wiring board, and the noise voltage near the center of the metal shell 5 is 82.7 [dBμV] to 87.0 [dBμV]. ]Met. On the other hand, FIG. 26 shows the distribution of noise voltage when each board connecting portion 40 is grounded to the ground of the wiring board, and the noise voltage near the center of the metal shell 5 is 71.8 [dBμV] to 78.3. [DBμV]. Therefore, when comparing the noise voltage near the center of the metal shell 5 of FIGS. 25 and 26, the noise voltage near the center of the metal shell 5 is 8 by grounding each board connecting portion 40 to the ground of the wiring board. It is reduced in the range of 0.7 [dBμV] to 10.9 [dBμV], and it can be seen that the effect of suppressing noise is obtained.

  If the data transmission clock frequency is increased to increase the data transmission speed of the memory card, the harmonic component of the clock frequency will affect the noise generated at the time of data transmission. The noise generated at the time of data transmission can be suppressed by escaping the noise generated at the time of data transmission of the memory card from each board connection portion 40 of the metal shell 5 to the ground of the wiring board. Therefore, by connecting the three board connecting portions 40 provided in the metal shell 5 to the ground of the wiring board and electrically connecting them, static electricity and external noise to each contact 3 can be prevented and each contact can be prevented. The radiation noise from 3 to the outside can be reduced. That is, noise generated during data transmission of the memory card can be released to the ground of the wiring board, and stable data transmission can be achieved while achieving high-speed data transmission.

  Further, the configuration of the memory card socket described above is not limited to the configuration illustrated in FIG. 1. For example, as shown in FIG. 24, each terminal portion 3 c of each contact 3 is led out rearward from the rear portion of the metal shell 5. The board connecting portion 40 may be bent from the left and right side surfaces of the lower shell 1 toward the wiring board side. The memory card socket shown in FIG. 1 and the memory card socket shown in FIG. 24 differ in the direction in which each terminal portion 3c of each contact 3 is led out from the rear portion of the metal shell 5 and bent.

  The memory card socket of the present embodiment described above can perform stable data transmission while increasing the data transmission speed.

DESCRIPTION OF SYMBOLS 1 Lower shell 1q Mated part 2 Upper shell 3 Contact 3b Contact piece 3c Terminal part 5 Metal shell 12 Contact block 13 Holding part 40 Board connection part

Claims (23)

  A plurality of metal shells that are formed in a rectangular tube shape having a card insertion opening on the front surface and that can be individually contacted with a metal shell into which a memory card is inserted and removed, and a plurality of I / O contact surfaces arranged in parallel on one surface of the memory card. A contact block held by a holding portion made of an insulating synthetic resin and mounted in a rear portion of the metal shell, provided on one end side of each contact of the contact block, The terminal portion joined to the signal conductive pattern formed on the wiring board is a memory card socket led out from the rear part of the metal shell, and the metal shell has a conductive potential that is a stable potential of the wiring board. A memory card socket, comprising at least three board connection portions that can be joined and electrically connected to a pattern.   2. The memory card socket according to claim 1, wherein the board connecting portion is provided at a corner of the metal shell.   2. The memory card socket according to claim 1, wherein at least one board connecting portion is provided at a central portion of one surface of the metal shell that faces the wiring board.   3. The memory card socket according to claim 2, wherein the board connecting portion is provided at two corners on the front side of the metal shell and one corner on the rear side of the metal shell.   2. The memory card socket according to claim 1, wherein the board connecting portion is provided in the vicinity of two corners on the front side of the metal shell and a rear edge of the metal shell.   2. The board connecting portion according to claim 1, wherein the board connecting portion is provided at two corners on the front side of the metal shell and at a central portion of one surface of the metal shell that faces the wiring board. Memory card socket.   2. The memory card socket according to claim 1, wherein the board connecting portion is provided in the vicinity of two corners on the rear side of the metal shell and a front end edge of the metal shell.   2. The memory according to claim 1, wherein the substrate connecting portion is provided at two corners on the rear side of the metal shell and at a central portion of one surface of the metal shell that faces the wiring board. Card socket.   3. The memory card socket according to claim 2, wherein the board connecting portion is provided at four corners of the metal shell.   10. The memory card socket according to claim 1, wherein the board connecting portion is a cut-and-raised piece formed by cutting and raising a part of the metal shell. 11.   10. The memory card socket according to claim 1, wherein the board connection portion is a protrusion formed by squeezing a part of the metal shell. 11.   10. The memory card according to claim 1, wherein the substrate connecting portion is a conductor layer formed by depositing a metal film on a part of the metal shell. 11. socket.   The cut-and-raised piece is extended from the metal shell in a lateral direction perpendicular to the insertion / extraction direction of the memory card in the metal shell in a direction perpendicular to the insertion / extraction direction of the memory card and the lateral direction of the metal shell. The memory card socket according to claim 10, wherein:   The metal shell is formed of a first metal plate and is located on the wiring board side, and an upper shell is formed of a second metal plate and is attached to one surface side of the lower shell. 11. The memory card socket according to claim 10, wherein the cut-and-raised piece protrudes rearward.   11. The memory card socket according to claim 10, wherein the cut-and-raised pieces are provided so as to protrude from both side portions of the metal shell in the left-right direction.   15. The memory card socket according to claim 14, wherein the cut-and-raised piece projects from the vicinity of the rear edge of the upper shell.   15. The memory card socket according to claim 14, wherein the cut-and-raised piece protrudes from both side edges in the left-right direction perpendicular to the insertion / extraction direction of the memory card in the upper shell.   12. The memory card socket according to claim 11, wherein the protrusion is formed at a corner of one surface of the metal shell that faces the wiring board.   10. The memory card according to claim 1, wherein the board connecting portion is a terminal piece connected to the metal shell and protrudes rearward of the metal shell. 11. Socket.   The board connection part is a terminal piece connected to both side parts of the metal shell, and protrudes in a direction orthogonal to the insertion / extraction direction of the memory card and the left-right direction of the metal shell. The memory card socket according to claim 1.   10. The memory card socket according to claim 1, wherein the board connecting portion is formed by welding or bonding to the metal shell. 11.   10. The memory card socket according to claim 1, wherein the board connecting portion is formed in pressure contact with both lateral sides of the metal shell. 11.   10. The memory card socket according to claim 1, wherein the board connecting portion is formed by being fitted to a fitted portion of the metal shell. 11.