Patent Grant
9692184
The present invention relates to an electronic device and particularly to an electronic device provided with an opening portion through which a memory card is inserted thereinto.
Electronic devices for memory cards are widely utilized. A memory card is inserted into or extracted from the electronic device through an opening portion. A printed wire board on which electronic components are mounted is fixed inside a case of the electronic device. The opening portion is provided at an arbitrary face of the electronic device. When in the case where a human body is electrically charged, the memory card is inserted into the electronic device, static electricity may be discharged toward the printed wire board thereof. An invention is known in which in order to protect the printed wire board of the electronic device from static electricity, a discharging conductive unit against static electricity is provided in the case (refer to Patent Documents 1 through 5). The discharging conductive unit is provided, for example, on a plane the same as that of the printed wire board. The discharging conductive unit is also referred to as an electrostatic induction plate.
In such an electronic device as described above, the discharging conductive unit (or the electrostatic induction plate) is disposed at a position nearest from the electronic device situated at the opening portion of the case. A memory card connector is mounted in the printed wire board in such a way that the respective centers of the opening portion of the memory card connector and the case coincide with each other. The memory card connector acts, as a discharging conductive unit, on the memory card connector side of the printed wire board. However, because no discharging conductive unit exists at the side, of the printed wire board, that is opposite to the memory card connector side thereof, static electricity may reach the memory card.
[Patent Document 1] Japanese Patent Application Laid-Open No. 2010-135230 (from 37th line of Page 5 to 8th line of Page 9, and FIG. 5)
[Patent Document 2] Japanese Patent Application Laid-Open No. 2003-229213
[Patent Document 3] Japanese Patent Application Laid-Open No. 2013-126132
[Patent Document 4] Japanese Patent Application Laid-Open No. 2006-195643
[Patent Document 5] Japanese Patent Application Laid-Open No. 2011-18746
The present invention has been implemented in order to solve the foregoing problem. With regard to a component such as a memory card connector, which is mounted in parallel with a printed wire board, the objective thereof is to obtain a structure that can raise at low cost the withstanding amount against static electricity from not only the memory card connector side of the printed wire board but also the side thereof opposite to the memory card connector side.
An electronic device according to the present invention includes a memory card connector that is provided with a loading opening for a memory card in the side face thereof and has a first sidewall and a second sidewall facing each other, a printed wire board that has a first main face and a second main face facing each other, on which a ground is formed, and on the first main face of which the memory card connector is placed leaving a margin at the loading opening side, and a resin case that contains the printed wire board and the memory card connector and in the sidewall of which at the loading opening side, an opening portion through which the memory card is inserted is formed. The electronic device according to the present invention is characterized in that on the second main face of the printed wire board, there are formed a first electrode and a second electrode that are connected with the ground, that are disposed on the respective ends thereof at the loading opening side, and that are independent from each other, and in that the first electrode is disposed below the first sidewall of the memory card connector and the second electrode is disposed below the second sidewall of the memory card connector.
In the present invention, an electrostatic-protection electrode is provided; therefore, with regard to a component such as a memory card connector, which is mounted in parallel with a printed wire board, it is possible to raise the withstanding amount against static electricity from not only the memory card connector side of the printed wire board but also the side thereof opposite to the memory card connector side.
Hereinafter, Embodiments of an electronic device according to the present invention will be explained in detail with reference to the drawings. The present invention is not limited to the following descriptions but can appropriately be modified within a scope that does not deviate from its spirits.
The electrode 6 (or the electrostatic induction plate 6) is disposed at one end, of the printed wire board 2, that is in the vicinity of the loading opening. The memory card connector 3 and the electrode 6 are connected with the ground layer (or the ground strip conductor) 2a by means of a via hole (or a wiring strip conductor) 2b. The electrode 6 can be formed in the same manner as the land on which components are mounted. For example, the electrode 6 can be formed in such a way that in a reflow process, a metal mask is utilized and a soldering paste is disposed. Because the memory card connector 3 is placed at a position, on the printed wire board 2, that is distal to the end face thereof in the vicinity of the loading opening, a margin 2x remains at a portion, of the printed wire board 2, that is in the vicinity of the loading opening. The electrode 6 is provided at a position, on the printed wire board 2, that is opposite to the memory card connector 3 side and is closer to the opening portion 5 than the memory card connector 3. It is desirable that the longitudinal width 6x of the electrode 6 is larger than the depth of a margin 2x.
When static electricity is applied from the upper portion of the memory card 4 to the printed wire board 2, the static electricity is led to the memory card connector 3. The memory card connector 3 prevents the static electricity from being applied to IC 7 by way of the gap 8 of the memory card 4. Because the memory card connector 3 is disposed in the electronic device 100, static electricity is hardly led from the upper portion of the memory card 4 to IC 7. As a result, the malfunction, caused by static electricity, in the circuit electrically connected with IC 7 can be suppressed.
When static electricity is applied from the lower portion of the memory card 4 to the printed wire board 2, the static electricity is hardly led to the memory card connector 3 because there exists almost no gap between the memory card 4 and the memory card connector 3. When there exists no electrode 6, static electricity may applied to IC 7 through the gap 8 of the memory card 4; however, even when applied to the opening portion 5, static electricity from a human body or static electricity generated by the discharging unit 9 can be led to the electrode 6 because the electrode 6 is provided. In comparison with the case where there exists no electrode 6, the withstanding amount against static electricity increases.
As described above, when the electrode 6 is provided in such a way as to be at the side, of the printed wire board 2, that is opposite to the memory card connector 3 side, to be larger than the transverse width of the memory card 4, and to be closer to the opening portion 5 than the memory card connector 3, static electricity can be led to the electrode 6 not only when the static electricity is applied from the opening portion 5 above the memory card 4 but also when the static electricity is applied from the lower portion of the memory card 4. Accordingly, static electricity can be suppressed from reaching IC 7 of the memory card 4; thus, in comparison with the case where there exists no electrode 6, the withstanding amount against static electricity can be raised at low cost.
The electrode 6 is disposed at one end, of the printed wire board 2, that is in the vicinity of the loading opening. The memory card connector 3 and the electrode 6 are connected with the ground layer (or the ground strip conductor) 2a by means of the via hole (or the wiring strip conductor) 2b. The electrode can be formed in the same manner as the land on which components are mounted. For example, the electrode 6 can be formed in such a way that in a reflow process, a metal mask is utilized and a soldering paste is disposed. Because the memory card connector 3 is placed at a position, on the printed wire board 2, that is distal to the end face thereof in the vicinity of the loading opening, the margin 2x remains at a portion, of the printed wire board 2, that is in the vicinity of the loading opening. The electrode 6 is provided at a position, on the printed wire board 2, that is opposite to the memory card connector 3 side and is closer to the opening portion 5 than the memory card connector 3. The longitudinal width of the electrode 6 is larger than the depth of the margin 2x.
For the purpose of making it possible that the memory card is inserted or extracted more easily, the electronic device 100 according to Embodiment 2 has the recess 11 in the opening portion 5 of the resin case 1. The distance between a human body or the discharging unit 9 and the electrode 6 is made shorter by the recess 11; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
In each of Embodiments 1 and 2, the electrode (or the electrostatic induction plate) 6 provided on the printed wire board 2 is disposed on the side, of the printed wire board 2, that is opposed to the memory card connector 3 side. In Embodiment 3, as illustrated in
Because this configuration make it possible to shorten the distance between the electrode 6 and the ground layer (or the ground strip conductor) provided on the printed wire board 2, the impedance against static electricity can be reduced and static electricity can be led to the position just in the vicinity of the opening portion 5; thus, the withstanding amount against static electricity is raised. Moreover, this configuration can be realized even when the mounting density of components on a printed wire board is high and hence no electrode can be provided on the printed wire board.
In the electronic device 100 according to Embodiment 3, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the electrode is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
As illustrated in
This configuration make it possible to shorten the distance between the electrode 6 and the ground layer (or the ground strip conductor) provided on the printed wire board 2. The impedance against static electricity can be reduced and static electricity can be led to the position just in the vicinity of the opening portion 5; thus, the withstanding amount against static electricity is raised. In comparison with the case where the electrode 6 is provided only on the side face of the printed wire board 2, it is made possible to further strongly connect the electrode 6 with the printed wire board 2.
In the electronic device 100 according to Embodiment 4, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the electrode is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
As illustrated in
In the case where at the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is large and at the portion other than the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is small, this configuration makes it possible to form the electrode 6 so as to have as small a size as critical mass; therefore, the space and the cost can be reduced.
In the electronic device 100 according to Embodiment 5, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the electrode is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
As illustrated in
In this configuration, the electrostatic protection structure becomes three-dimensional; thus, static electricity can more readily be discharged. Moreover, the distance between the board-mounting capacitor 10 and the ground layer or the ground strip conductor provided on the printed wire board 2 can be shortened; therefore, the impedance against static electricity can be reduced.
In the electronic device 100 according to Embodiment 6, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the board-mounting capacitor 10 is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the board-mounting capacitor 10 and hence the withstanding amount against static electricity can further be raised.
The electrode 6 (or the electrostatic induction plate 6) may be disposed on the inner surface of the resin case 1, as illustrated in
The electrode 6 is formed on the side wall 1x, of the resin case 1, that is in the vicinity of the loading opening. The transverse width (W) of the electrode 6 is larger than the transverse width of the loading opening 3a of the memory card connector 3 or the transverse width of the memory card 4. Because this configuration makes it possible to lead static electricity at a position just in the vicinity of the opening portion 5, the withstanding amount against static electricity is raised. Moreover, this configuration can be realized even when the mounting density of components on a printed wire board is high and hence no electrode can be provided on the printed wire board.
In the electronic device 100 according to Embodiment 7, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the electrode is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
As illustrated in
The electrode 6 is led to the printed wire board 2 by way of such a wiring lead and then is connected with the ground strip conductor on a layer the same as that of the memory card connector 3 or connected with the ground strip conductor on a layer different from that of the memory card connector 3 through the via hole 2b. In the case where at the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is large and at the portion other than the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is small, this configuration makes it possible to form the electrode 6 so as to have as small a size as critical mass; therefore, the cost can be reduced.
In the electronic device 100 according to Embodiment 8, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the electrode is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the electrode 6 and hence the withstanding amount against static electricity can further be raised.
As illustrated in
The distance (L) between the respective outer edges of the board-mounting capacitors 10a and 10b is larger than the transverse width (Wo) of the loading opening 3a provided in the memory card connector 3. In this configuration, the electrostatic protection structure becomes three-dimensional; thus, static electricity can more readily be discharged. Moreover, because this configuration makes it possible to lead static electricity at a position just in the vicinity of the opening portion 5, the withstanding amount against static electricity is raised. Furthermore, this configuration can be realized even when the mounting density of components on a printed wire board is high and hence no electrode can be provided on the printed wire board.
In the electronic device 100 according to Embodiment 9, for the purpose of making it possible that the memory card 4 is inserted or extracted more easily, the lower section of the opening portion 5 of the resin case 1 is recessed toward the printed wire board 2. When the recess is formed, the distance between a human body or the discharging unit 9 and the board-mounting capacitor 10 is shortened; therefore, static electricity from the human body or static electricity generated by the discharging unit 9 can further readily be led to the board-mounting capacitor 10 and hence the withstanding amount against static electricity can further be raised.
When the metal electrostatic induction plate formed on the rear side of the printed wire board 2 is configured with three or more small strips, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the electrostatic induction plate is weak. It is preferable that electronic components susceptible to static electricity are mounted in the place having a weak field intensity. It is desirable that the distance (L) between the respective outer edges of the electrostatic induction plates 6a and 6b, arranged at the outmost positions, is larger than the transverse width (Wo) of the loading opening 3a of the memory card connector 3 or the transverse width (Wm) of the memory card 4. Hereinafter, there will be described the behavior of static electricity from a human body or static electricity generated by the discharging unit 9, which are applied to the opening portion 5.
When static electricity is applied from the upper portion of the memory card 4 to the printed wire board 2, the static electricity is led to the memory card connector 3. The memory card connector 3 prevents the static electricity from being applied to IC 7 by way of the gap 8 of the memory card 4. Because the memory card connector 3 is disposed in the electronic device 100, static electricity is hardly led from the upper portion of the memory card 4 to IC 7. As a result, the malfunction, caused by static electricity, in the circuit electrically connected with IC 7 can be suppressed.
When static electricity is applied from the lower portion of the memory card 4 to the printed wire board 2, the static electricity is hardly led to the memory card connector 3 because there exists almost no gap between the memory card 4 and the memory card connector 3. However, in the case where only a single electrostatic induction plate is provided, an electromagnetic field generated by a current produced when static electricity is led to the electrostatic induction plate may cause an abnormality in communication between the memory card 4 and the electronic device 100. Because in Embodiment 10, the electrostatic induction plates 6c through 6e are provided, static electricity from a human body or static electricity generated by the discharging unit 9 can be led to the electrostatic induction plate 6. In other words, in comparison with the case where the electrostatic induction plates 6c through 6e are not provided, the withstanding amount against static electricity is raised.
The plurality of electrostatic induction plates 6 are provided at positions on the side, of the printed wire board 2, that is opposite to the memory card connector 3 side; the positions are closer to the opening portion 5 than the memory card connector 3. The distance between the respective outmost edges of the plurality of electrostatic induction plates 6 is larger than the transverse width of the memory card 4. Accordingly, not only when static electricity is applied from the opening portion above the memory card 4 but also when static electricity is applied from the lower portion of the memory card, the static electricity can be led to the plurality of electrostatic induction plates 6. Moreover, the static electricity can be suppressed from reaching IC 7 of the memory card 4, and it is made possible to locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the electrostatic induction plate is weak. When IC 7 of the memory card 4, which is susceptible to electromagnetic noise, is disposed at this position where the electric-field intensity is locally weak, the withstanding amount against static electricity can be raised at low cost.
In Embodiment 11, the electrostatic induction plate formed on the side face, of the printed wire board 2, that is in the vicinity of the loading opening is configured with three or more small strips. As a result, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the electrostatic induction plate is weak; therefore, components susceptible to static electricity can be mounted. It is desirable that the distance (L) between the respective outer edges of the electrostatic induction plates 6a and 6b, arranged at the outmost positions, is larger than the transverse width (Wo) of the loading opening 3a of the memory card connector 3 or the transverse width (Wm) of the memory card 4.
Because this configuration makes it possible to lead static electricity at a position just in the vicinity of the opening portion 5, the withstanding amount against static electricity is raised. Moreover, this configuration can be realized even when the mounting density of components on a printed wire board is high and hence no electrostatic induction plate can be provided on the printed wire board. Furthermore, in the case where at the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is large and at the portion other than the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is small, this configuration makes it possible to form the electrostatic induction plate 6 so as to have as small a size as critical mass; therefore, the cost can be reduced. When the electrostatic induction plate is configured with three or more small strips, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the electrostatic induction plate is weak; therefore, components susceptible to static electricity can be mounted.
When the board-mounting capacitor formed on the rear side of the printed wire board 2 is configured with three or more small strips, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the board-mounting capacitor is weak. It is preferable that components susceptible to static electricity are mounted in the place having a weak field intensity. It is desirable that the distance (L) between the respective outer edges of the board-mounting capacitors 10a and 10b, arranged at the outmost positions, is larger than the transverse width (Wo) of the loading opening 3a of the memory card connector 3 or the transverse width (Wm) of the memory card 4. When the board-mounting capacitor is configured with three or more small strips, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the board-mounting capacitor is weak; therefore, components susceptible to static electricity can be mounted.
Because this configuration makes it possible to lead static electricity at a position just in the vicinity of the opening portion 5, the withstanding amount against static electricity is raised. Moreover, this configuration can be realized even when the mounting density of components on a printed wire board is high and hence no electrostatic induction plate can be provided on the printed wire board. Furthermore, in the case where at the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is large and at the portion other than the both ends of the memory card 4, the gap 8 of the division plane between the upper and lower portions is small, this configuration makes it possible to form the board-mounting capacitor 10 so as to have as small a size as critical mass; therefore, the cost can be reduced. When the board-mounting capacitor is configured with three or more small strips, it is made possible to more locally create the place where the intensity of an electromagnetic field generated by a current produced when static electricity is led to the board-mounting capacitor is weak; therefore, components susceptible to static electricity can be mounted.
In the scope of the present invention, the embodiments thereof can freely be combined with one another and can appropriately be modified or omitted.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2013-125251 | Jun 2013 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2014/061820 | 4/28/2014 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2014/199738 | 12/18/2014 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 20110317378 | Wang et al. | Dec 2011 | A1 |
| Number | Date | Country |
|---|---|---|
| 2001 308586 | Nov 2001 | JP |
| 2003 229213 | Aug 2003 | JP |
| 2004 134453 | Apr 2004 | JP |
| 2008 153179 | Jul 2008 | JP |
| 2008 181689 | Aug 2008 | JP |
| 2008 226786 | Sep 2008 | JP |
| 201201635 | Jan 2012 | TW |
| Entry |
|---|
| International Search Report Issued Jul. 29, 2014 in PCT/JP14/061820 Filed Apr. 28, 2014. |
| Japanese Office Action Issued Aug. 18, 2015 in a corresponding JP Application No. JP2015 522638 with English translation. |
| Combined Taiwanese Office Action and Search Report issued Feb. 19, 2016 in Patent Application No. 103118546 (with English language translation). |
| Number | Date | Country | |
|---|---|---|---|
| 20160056581 A1 | Feb 2016 | US |
