JPH09232779A - Laminated structure of electronic circuit unit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To inhibit the generation of electromagnetic waves generated by a high-frequency noise current in electronic circuit units and a convection guide plate mounting frame. SOLUTION: Shielding members 27, which are mounted at a pitch roughly equal with the mounting pitch of electronic circuit packages 18, are formed in a thickness roughly equal with that of the packages 18, consist of a conductor and respectively have each slit 28, are mounted in the intake vent and exhaust vent of a convection induction plate mounting frame 17 and at the same time, a conductive part is formed on the peripheral edge of each electronic circuit package 18. When these packages 18 are inserted in electronic circuit units 16, the upper and lower parts of the insertion ports of the units 16 and the above conductive parts are made to connect with each other and the units 16 and the frame 17 are connected with each other by a conductive material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stacking of electronic circuit units for air-cooling each electronic circuit package when a plurality of electronic circuit units mounted with the electronic circuit packages are mounted in a cabinet of a telephone exchange or the like. Regarding the structure, in particular, EMI (ELECTRO MAGNET) which suppresses high frequency noise generated from the intake port and the exhaust port of the convection guide plate mounting frame and the insertion port of the electronic circuit package of the electronic circuit unit.
IC INTERFERENCE) is a useful measure.

[0002]

2. Description of the Related Art A conventional laminated structure of an electronic circuit unit will be described below with reference to the drawings. 6 is a side view of the internal structure of the cabinet, FIG. 7 is a rear view of the cabinet, and FIG.
Is a schematic view of a main part of a conventional cabinet front side, and FIG. 9 is a perspective view of a conventional convection guide mounting frame.

As shown in FIG. 6, inside a cabinet 1, an electronic circuit unit 3 and a convection guide plate mounting frame 4 are alternately stacked on a conductive frame 2. Further, an outside cable 5 is provided on the back side of the cabinet 1, and as shown in FIG.
Are connected to each electronic circuit unit 3. The electronic circuit unit 3 is formed of a hollow casing made of a conductor, and a plurality of electronic circuit packages 7 having electronic components 6 mounted thereon are erected on a side wall thereof at a constant pitch, as shown in FIG. The insertion opening 8 for insertion is opened. In addition, a plurality of connectors (not shown) are arranged on the inner surface of the side wall facing the insertion port 8, and the connectors are connected to the outside cable 5. Further, ventilation holes (not shown) are formed on the upper and lower surfaces thereof. In addition,
The air holes are similar to the air holes on the upper and lower surfaces of the convection guide plate mounting frame 4, which will be described later.

As shown in FIG. 9, the convection guide plate mounting frame 4 is formed of a hollow casing 9 made of a conductor, and ventilation holes 10 are formed in the upper and lower surfaces thereof. Further, an intake port 11 is provided and opened on the side wall thereof, and an exhaust port 12 is formed on a side wall surface facing the intake port 11. Exhaust port 1
2 is open to the upper side so that warmed air rises so that it can be easily exhausted, and the lower exhaust port 1
The lower part is closed so that the air exhausted from 2 does not flow into the convection guide plate mounting frame 4. A convection guide plate 13 is obliquely attached inside the hollow housing 9 so that the intake port 11 side is on the lower side and the exhaust port 12 side is on the upper side. The inside of the convection guide mounting frame 4 is partitioned by the convection guide plate 13, and the air taken in from the intake port 11 rises along the convection guide plate 13 while being heated by the heat from the electronic circuit unit 3 located above, It is designed to flow out from the vent hole 10 on the upper surface. The air that has flowed out enters the electronic circuit unit 3 as shown by the arrow in FIG. 6, cools the electronic circuit package 7, and flows into the convection guide plate mounting frame 4 above it from the ventilation holes 10 on the lower surface. Then, the inflowing air rises along the convection guide plate 13 and is exhausted from the exhaust port 12. Since the insertion port 8 of the electronic circuit unit 3 is open, air also flows in from the insertion port 8,
The electronic circuit package 7 is cooled, and the air at this time is also exhausted from the exhaust port 12 described above.

[0005]

In the laminated structure of the electronic circuit unit described above, each housing resonates due to the high frequency noise generated by the electronic circuit package, and the high frequency noise current causes the convection induction plate mounting frame and the electronic circuit unit. Induce in the case of. Therefore, in order to ground the high-frequency noise current, for example, as shown in FIG. 8, the convection guide plate mounting frame 3 and the electronic circuit unit 4 are provided with terminals 14, and the terminals 14 are conductive frames. 2 is connected to the bottom of the conductive frame 2.
5 are connected.

However, in the conventional laminated structure of the electronic circuit unit, the high frequency noise current tries to flow into the frame ground, but the intake port and the exhaust port of the convection induction mounting frame and the insertion port of the electronic circuit unit have high frequency noise. Since it acts as a resistance to electric current, a potential difference is generated between the upper and lower sides of the intake port, the exhaust port and the insertion port. Therefore, the intake port, the exhaust port, and the insertion port act as a kind of slot antenna, and the intake port,
Wavelength λ / 2 with half the length of the sides of the exhaust port and insertion port
There was a problem of generating electromagnetic waves. There is a problem that this electromagnetic wave is transmitted from each mouth to the outside of the housing. Furthermore, at the exhaust port, cables between units mounted inside the cabinet, cables between units, and cables that go out of the cabinet are wired, so the electromagnetic waves and the high-frequency noise are transferred to these cables, and the cables outside the cabinet are There was a problem that electromagnetic waves were emitted.

On the other hand, the resonance frequency due to the radiation of the electromagnetic wave is in the frequency range (3
Since it is defined as 0 MHz to 1000 MHz), it must be designed so as to be out of the range. However, in the conventional laminated structure of the electronic circuit unit, it is difficult to design it so as to shift it to a high range outside the range, and there is a problem that the degree of freedom in design is reduced.

[0008]

Therefore, in the laminated structure of the electronic circuit unit of the present invention, conductors are arranged at the intake port and the exhaust port of the convection guide plate mounting frame so as to be electrically connected in the vertical direction and to the electronic circuit unit. The convection guide plate mounting frame is electrically connected to the ground. It is preferable to arrange a plurality of conductors at intervals. The conductors are preferably arranged at a pitch substantially equal to the mounting pitch of the electronic circuit package mounted in the electronic circuit unit. The conductor preferably has a thickness substantially equal to that of the electronic circuit package mounted on the electronic circuit unit. It is preferable that the conductor has a depth and has a cylindrical shape.

Further, in the laminated structure of the electronic circuit unit of the present invention, a conductive portion which communicates at least the upper and lower sides of the electronic circuit package is formed, and when the electronic circuit package is inserted into the electronic circuit unit, the electronic circuit unit is inserted. The upper and lower sides of the mouth are connected to the conductive portion, and the electronic circuit unit and the convection guide plate mounting frame are electrically connected to each other so as to be connected to the ground. It is preferable to form the conductive portion by plating.

Further, in the laminated structure of the electronic circuit unit according to the present invention, a conductor is arranged at the intake port and the exhaust port of the convection guide plate mounting frame to electrically connect the upper and lower parts, and at least the upper and lower parts of the electronic circuit package communicate with each other. It is preferable that the electronic circuit unit and the convection guide plate mounting frame are electrically connected to each other and are connected to the ground. Furthermore, it is preferable that the electronic circuit unit and the convection guide plate mounting frame are connected by a conductive member made of an elastic body.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. 1 is a schematic view of a main part of a cabinet front side, FIG. 2 is a perspective view of a convection guide mounting frame, FIG. 3 is an exploded perspective view of a convection guide plate mounting frame, FIG. 4 is an exemplary view of an electronic circuit package, and FIG. It is a connection state figure of a circuit unit and a convection guide plate attachment frame. It should be noted that the same structure as the conventional one and the action of air cooling will be omitted, and in the case of explanation, the explanation will be simplified.

First, the structure peculiar to this embodiment will be mainly described. That is, in FIG. 1, as in the conventional case, an electronic circuit unit 16 and a convection induction plate mounting frame 17 are alternately stacked on the conductive frame 15 and set inside a cabinet (not shown). In addition, an outside cable (not shown) is provided on the back side of the cabinet, as in the conventional case.

The electronic circuit unit 16 is formed of a hollow casing made of a conductor, and the side wall of the electronic circuit unit 16 has a plurality of electronic circuit packages 18 on which electronic components 6 are mounted. The mouth 19 is open. In addition, a plurality of connectors (not shown) are arranged on the inner surface of the side wall facing the insertion port 19, and the connectors are connected to the outside cable. The pores are perforated as in the conventional case. The ventilation holes are the same as the ventilation holes on the upper and lower surfaces of the convection guide plate mounting frame 17, as in the conventional case.

Here, what is different from the conventional one is the electronic circuit package 18, and in this electronic circuit package 18, as shown in FIG.
The conductive portion 22 is formed on the peripheral edge except the side having 1.
The conductive portion 22 is formed by, for example, a plating process, and a copper-nickel plated layer is formed on the printed board 20. When the electronic circuit package 18 is inserted into the electronic circuit unit 16, the conductive portion 22 contacts the upper and lower sides of the insertion opening 18 of the electronic circuit unit 16 to be electrically connected. It should be noted that the conductive portion 22 may be formed on the front surface side of the electronic circuit package 16 when it is mounted on the electronic circuit unit 16 so as to communicate with at least the upper and lower sides of the electronic circuit package 18.

As shown in FIGS. 2 and 3, the convection guide plate mounting frame 17 is formed of a hollow casing 23 made of a conductor, and ventilation holes 24 are formed in the upper and lower surfaces thereof. Further, an intake port 25 is provided on the side wall thereof and opened, and an exhaust port 26 is formed on a side wall surface facing the intake port 25.
A shield member 27 is fitted and attached to the intake port 25. The shield member 27 has a slit 28 made of a conductor and having a pitch substantially equal to the mounting pitch of the electronic circuit package 18 and having a thickness substantially equal to that of the electronic circuit package 18, formed in a frame 29 made of the conductor. .

The exhaust port 26 is opened upward so that warmed air rises and is easily exhausted.
Moreover, the air rising from below is attached to the convection guide plate mounting frame 1
A shield member 30 formed by closing the lower part so as not to flow into the inside 7 is fitted and attached. Similar to the shield member 27, the shield member 30 has a pitch substantially equal to the mounting pitch of the electronic circuit package 18,
A slit 31 made of a conductor having a thickness substantially equal to that of the electronic circuit package 18 is formed in a frame 32 made of a conductor.

The depth of the shield members 27, 30 is preferably as long as possible. This is because by making it long, it becomes a kind of waveguide, and it is possible to greatly reduce electromagnetic interference waves. However, in order to equalize the inflow velocity of the air flowing in from each slit 28 and to equalize the amount of air flowing out from each slit 31, a space in which the static pressure can be adjusted is created in the convection guide plate mounting frame 17. It is necessary to consider the point. The static pressure adjustment is performed so that the inflowing cooling air uniformly strikes each electronic circuit package 18.

That is, as in the conventional case, the convection guide plate 33 is obliquely attached inside the hollow casing 23 so that the intake port 25 side is on the lower side and the exhaust port 26 side is on the upper side. A space is formed so that the slits 28 and 31 are not provided in the portion where the guide plate 33 is provided. The inside of the convection guide mounting frame 23 is partitioned by the convection guide plate 33, and the air taken in through the intake port 25 is warmed by the heat from the electronic circuit unit 16 located above and along the convection guide plate 33. The point where it rises and flows out from the ventilation hole 23 on the upper surface, and the air that has flowed out enters the electronic circuit unit 16 to cool the electronic circuit package 18, and the convection guide plate mounting frame 17 above it. It is the same as the conventional one in that it flows in from the ventilation hole 23 on the lower surface, rises along the convection guide plate 33, and is exhausted from the exhaust port 26. However, since the slits 28 and 31 are provided on the intake port 25 side and the exhaust port 26 side, air flows in and out at the portion surrounded by the slits 28 and 31. Further, as shown in FIG. 8, since the insertion port 19 of the electronic circuit unit 16 is open, the insertion port 1
Air also flows in from 9 to cool the electronic circuit package 18, and the air at this time is exhausted from the exhaust port 26 side.
It is the same as the conventional one.

On the other hand, the electronic circuit unit 16 and the convection guide plate mounting frame 17 are electrically connected by a conductive material called a so-called shield finger. For example, as shown in FIG. 5, this shield finger is preferably made of an elastic material 34 such as a spring to electrically connect the respective members to each other and to apply a biasing force thereto. This is for maintaining the electronic circuit unit 16 in the laminated state. Next, the flow of the high frequency noise current due to the laminated structure of the electronic circuit unit will be described.

Returning to FIG. 1, when a high frequency noise current is generated in the electronic circuit unit 16 and the convection induction plate mounting frame 17, for example, when the potential on the A side in the drawing becomes high, the electronic circuit on the upper side is increased. A high-frequency noise current flows from the top to the bottom of the conductive portion 22 (see FIG. 4) of each electronic circuit package 18 in the unit 16, as indicated by the solid arrow,
Slit 2 of shield member 27 of convection guide plate mounting frame 17
8 to the frame ground 35 through the conductive portion 22 of each electronic circuit package 18 in the lower electronic circuit unit.

On the other hand, the outlet 26 of the convection guide plate mounting frame 17
On the side, as in the case of the intake port 25, since the high frequency noise current flows through the slit 31 of the shield member 31, the potential difference at the intake port 25 becomes small.
Details of this are the same as in the case of the intake port 25, and will be omitted. Further, similarly to the conventional case, terminals are provided in the electronic circuit unit 16 and the convection guide plate mounting frame 17 so that the conductive portion 15 is directly grounded from each electronic circuit unit 16 and the convection guide plate mounting frame 17, and the broken line is shown. It is preferable to make it flow as shown by the arrow. This is because the purpose is to make the potential difference between the upper and lower sides of the electronic circuit unit 16 and the convection guide plate mounting frame 17 as small as possible.

According to the laminated structure of the electronic circuit unit of the above-mentioned embodiment, since the high frequency noise current is easily grounded by the slit and the conductive portion of the electronic circuit package, the upper and lower parts of the electronic circuit unit and the convection induction plate mounting frame are arranged. The potential difference becomes small, and it becomes possible to suppress the emission of electromagnetic waves by a kind of slot antenna. Therefore, the resonance frequency due to the radiation of the electromagnetic wave is
The frequency range (30 MHz to 1
It is easy to design so as to shift to a high frequency range outside 000 MHz), and the effect of increasing the degree of freedom in design can be expected.

In addition, the static pressure can be adjusted in the space in which the convection guide plate is installed, and the depth of the slit is made as long as possible, so that a kind of waveguide is formed in the slit portion to prevent electromagnetic interference. The effect of significant reduction can be expected. In the above embodiment, the case of the natural air cooling method in which the air in the atmosphere is allowed to naturally flow in through the intake port or the like has been described, but the forced air cooling method in which a fan or the like is arranged to force air cooling. In the case of, it can be carried out in the same manner.

Further, the electronic circuit unit is not limited to a telephone exchange or the like, and any electronic unit having a unit structure can be similarly implemented. Furthermore, a case has been described in which the conductive portion is formed in the electronic circuit package set in the electronic circuit unit so as to cancel the potential difference above and below the insertion opening of the electronic circuit unit, but the present invention is not limited to this. The shield member attached to the convection guide plate attachment frame in the embodiment may be attached to the insertion opening of the electronic circuit unit. As a result, the potential difference of the electronic circuit unit can of course be canceled out.

[0025]

As described above, according to the laminated structure of the electronic circuit unit of the present invention, since the high frequency noise current is easily grounded by the conductor and the conductive portion of the electronic circuit package, the electronic circuit unit and the convection induction are provided. The potential difference between the upper and lower sides of the plate mounting frame is reduced, and the effect of suppressing the emission of electromagnetic waves by a kind of slot antenna is obtained.

Therefore, it becomes easy to design so that the resonance frequency due to the radiation of the electromagnetic wave is shifted to a high range outside the frequency range (30 MHz to 1000 MHz) according to the electromagnetic interference wave standard of the VCCI standard, and the degree of freedom in designing is increased. You can expect the effect of increasing.

[Brief description of drawings]

FIG. 1 is a schematic view of a main part of a front side of a cabinet according to an embodiment.

FIG. 2 is a perspective view of a convection guide plate mounting frame according to the embodiment.

FIG. 3 is an exploded perspective view of a convection guide plate mounting frame according to the embodiment.

FIG. 4 is an exemplary diagram of an electronic circuit package according to an embodiment.

FIG. 5 is a connection state diagram of an electronic circuit unit and a convection guide plate mounting frame.

FIG. 6 is a view showing an example of the internal structure of a cabinet.

[Figure 7] Back view of the cabinet

FIG. 8 is a schematic view of a main part of a conventional cabinet front side.

FIG. 9 is a perspective view of a conventional convection guide plate mounting frame.

[Explanation of symbols]

 15 conductive part 16 electronic circuit unit 17 convection guide plate mounting frame 18 electronic circuit package 19 insertion port 22 conductive part 24 vent hole 25 intake port 26 exhaust port 27 shield member 28 slit 30 shield member 31 slit 33 convection guide plate

Claims (9)

[Claims] 1. An electronic circuit unit having an opening on a side surface and a convection guide plate mounting frame in which an intake port and an exhaust port formed on opposite side surfaces are partitioned by a convection guide plate are alternately stacked and mounted in a cabinet. In the laminated structure of the electronic circuit unit configured as described above, conductors are arranged at the intake port and the exhaust port of the convection guide plate mounting frame to electrically connect the upper and lower sides, and the electronic circuit unit and the convection guide plate mounting frame are electrically connected. A laminated structure of an electronic circuit unit characterized by being connected to the ground. 2. The electronic circuit unit structure according to claim 1, wherein a plurality of conductors are arranged at intervals. 3. The electronic circuit unit structure according to claim 2, wherein the conductors are arranged at a pitch substantially equal to a mounting pitch of an electronic circuit package mounted on the electronic circuit unit. 4. The laminated structure of an electronic circuit unit according to claim 2, wherein the conductor has a thickness substantially equal to that of an electronic circuit package mounted on the electronic circuit unit. 5. The laminated structure of an electronic circuit unit according to claim 1, claim 2, claim 3 or claim 4, wherein the conductor has a cylindrical shape with a depth. 6. An electronic circuit unit having an opening on a side surface, and a convection guide plate mounting frame in which an intake port and an exhaust port formed on the opposite side surface are partitioned by a convection guide plate are alternately stacked and mounted on a cabinet. In the laminated structure of the electronic circuit unit thus configured, at least a conductive portion that communicates at least the upper and lower sides of the electronic circuit package is formed, and when the electronic circuit package is inserted into the electronic circuit unit, the upper and lower sides of the insertion opening A laminated structure of an electronic circuit unit, characterized in that the electronic circuit unit and the convection guide plate mounting frame are electrically connected to each other while being connected to the conductive portion. 7. The laminated structure of an electronic circuit unit according to claim 6, wherein the conductive portion is formed by plating. 8. An electronic circuit unit having an opening on a side surface and a convection guide plate mounting frame formed by partitioning an intake port and an exhaust port formed on opposite side surfaces are alternately stacked and mounted on a cabinet. In the laminated structure of the electronic circuit unit configured as described above, conductors are arranged at the intake port and the exhaust port of the convection guide plate mounting frame to make the upper and lower parts electrically conductive and to form at least the upper and lower conductive parts of the electronic circuit package. A laminated structure of an electronic circuit unit, wherein the electronic circuit unit and the convection guide plate mounting frame are electrically connected to each other and connected to the ground. 9. The electronic circuit unit according to claim 1, 6, or 8, wherein the electronic circuit unit and the convection guide plate mounting frame are connected by a conductive member made of an elastic body. Laminated structure.