JPH0661674A - Mounting structure for electronic device - Google Patents

Abstract

PURPOSE:To realize high density mounting of an electronic circuit by eliminating thermal interference between a high heating electronic circuit and a low heating electronic circuit. CONSTITUTION:In the mounting structure for an electronic device where a circuit board P mounting electronic circuits of electronic devices is mounted vertically on a frame body, the circuit board P is partitioned into a board section 11 mounting a high heating electronic circuit and a section 12 mounting a low heating electronic circuit arranged on the right and left through a thermal insulating section 13.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic device having a high-heat generating electronic circuit and a low-heat generating electronic circuit, for example, a mounting structure of an electronic device for enabling high density mounting of subscriber circuits in a digital telephone exchange. , In particular, the circuit board is divided into a high-heat-generating board part on which a high-heat-generating electronic circuit is mounted and a low-heat-generating board part on which a low-heat-generating electronic circuit is mounted, and the disposition of the high-heat generating board part and the low-heat generating board part is improved. By doing so, mutual thermal interference between the high heat generation substrate portion and the low heat generation substrate portion is eliminated, and high density mounting of the circuit board of the electronic device is possible.

[0002]

2. Description of the Related Art A mounting structure of an electronic device as described above is disclosed, for example, in Nov. Nippon Telegraph and Telephone Public Corporation. Author of Research Practical Report, Vol. 31, No. 11, "Concentration system and subscriber circuit of digital subscriber line exchange". It is listed in Takeo Onuma et al. FIG. 10 is a diagram for explaining a conventional mounting structure of an electronic device of this type, in which P is a printed wiring circuit board (hereinafter, referred to as a circuit board).
The high heat generation substrate section 1 in which the high heat generation electronic circuit is incorporated is arranged in the upper portion and the low heat generation substrate section 2 in which the low heat generation electronic circuit is incorporated is arranged in the lower portion when the The high temperature air was prevented from affecting the low heat generation substrate section 2.

FIG. 11 shows an example of a conventional mounting structure of an electronic circuit on a circuit board P. In this example, there are two electronic circuits in which a high heat generating substrate portion 1 and a low heat generating substrate portion 2 are combined. One is incorporated. In each electronic circuit, a signal is input from the input terminal 3 to the low heat generating electronic circuit such as an integrated circuit incorporated in the low heat generating substrate portion 2 through the wiring 4, and the output signal from the low heat generating electronic circuit is output to the wiring 5. Is input to a high-heat generating electronic circuit such as a power transistor incorporated in the high-heat generating substrate section 1, and an output signal from the high-heat generating electronic circuit is output to the output terminal 7 through the wiring 6.

Generally, components for high heat-generating electronic circuits have high heat resistance, for example, the allowable junction temperature of power transistors is 150 ° C. to 175 ° C., whereas that of integrated circuits used in low-heat generating electronic circuits is allowable. The junction temperature is often 125 ° C. Therefore, in the conventional mounting structure, it is divided into a high-heat-generating substrate portion 1 on which a high-heat-generating electronic circuit is mounted and a low-heat-generating substrate portion 2 on which a low-heat-generating electronic circuit is mounted.
As shown in 0, when the circuit board P is erected, the high heat generation substrate portion 1 is arranged in the upper portion and the low heat generation substrate portion 2 is arranged in the lower portion,
By utilizing the property that the light high temperature air rises from the high heat generation substrate unit 1, the high temperature air is prevented from affecting the low heat generation substrate unit 2.

However, when a circuit board of an electronic device in which a high-heat-generating electronic circuit and a low-heat-generating electronic circuit are incorporated in the circuit board in the mounting structure as described above is mounted on a frame or the like in a plurality of stages in the vertical direction. The high temperature air rising from the high heat generating board portion of the circuit board of the lower electronic device flows into the low heat generating board portion of the circuit board of the upper electronic device and adversely affects it. Therefore, conventionally, in order to prevent this, as shown in FIG. 12, a convection induction plate 8 is obliquely provided between the upper circuit board P and the lower circuit board P so that the lower circuit board P is By guiding the rising high temperature airflow to the outside so as not to flow into the upper circuit board P, the low heat generation substrate portion 2 of the upper circuit board P is prevented from overheating.

[0006]

However, as shown in FIG. 11 described above, the high heat generation substrate section in which the high heat generation electronic circuit is incorporated and the low heat generation substrate section in which the low heat generation electronic circuit is incorporated are connected. In the case where a plurality of circuit boards P are mounted on a single circuit board P, the upper part of the high heat generation board part 1 and the lower part of the low heat generation board part 2 are connected in the vertical direction by the wiring 5, and Since the input terminal 3 provided on the side portion and the low heat generation substrate portion 2 are connected in the lateral direction by the wiring 4, there is a problem that the connections are crossed between the circuits. Further, as shown in FIG. 12, when a plurality of circuit boards P each having an electronic device incorporated therein by the conventional mounting structure are vertically installed on a frame body or the like and vertically mounted, a circuit in the upper stage is used. Since the upper and lower spaces must be opened by the installation space of the convection guide plate 8 provided between the board P and the lower circuit board P, there is a disadvantage that the density of the electronic device cannot be increased as a whole.

According to the present invention, when a plurality of circuit boards are erected vertically and mounted in multiple stages in a vertical direction, a plurality of circuit boards are mounted without providing a convection guide plate for each circuit board, and then the uppermost stage is mounted. A convection guide plate can be provided above, increasing the packaging density as a whole, and mounting multiple electronic devices that combine a high heat generation electronic circuit and a low heat generation electronic circuit on a single circuit board. Another object of the present invention is to provide a mounting structure of an electronic device in which wirings between circuits do not intersect with each other.

[0008]

In order to solve the above-mentioned problems, the present invention provides a mounting structure of an electronic device, in which a circuit board on which an electronic circuit of the electronic device is mounted is erected vertically in a frame body, It is divided into a high-heat-generating board part on which a high-heat-generating electronic circuit is mounted and a low-heat-generating board part on which a low-heat-generating electronic circuit is mounted. The high-heat generating board part and the low-heat generating board part are laterally separated by a heat insulating part. The electronic device mounting structure is characterized in that it is arranged at a position.

[0009]

Since the low heat generation substrate section and the high heat generation substrate section are arranged in the left-right direction position, even if a plurality of such circuit boards are vertically mounted in multiple stages, the low heat generation substrate section is placed under the high heat generation substrate section. Since the heat generating substrate is not arranged, it is possible to prevent the high temperature air after cooling the high heat generating substrate from flowing into the low heat generating substrate. Further, since the low heat generation board part and the high heat generation board part in the single circuit board are arranged via the heat insulation part, it is possible to reduce the flow of heat from the high heat generation board part to the low heat generation board part. You can

Further, even if a plurality of circuit boards are installed upright in multiple stages, it is not necessary to provide a convection guide plate between each stage of the circuit boards, and convection induction is provided above the uppermost circuit board. A plate may be provided. Further, it is possible to optimize the thermal design of each of the high heat generation substrate portion and the low heat generation substrate portion in accordance with the temperature condition of the electronic circuit element forming the electronic circuit, which enables high-density mounting of the electronic device. Further, even when a plurality of electronic circuits are mounted on a single circuit board, each electronic circuit is formed by connecting the low heat generation board section and the high heat generation board section arranged at the left and right positions. Interlocking of connections between electronic circuits is eliminated.

[0011]

1 and 2 show a first embodiment of the present invention. In the present invention, a high heat generating substrate portion 11 having a high heat generating electronic circuit mounted on a circuit board P and a low heat generating electron are mounted. The circuit board is divided into a low heat generation substrate section 12 on which a circuit is mounted, and the high heat generation substrate section 11 and the low heat generation substrate section 12 are arranged at the left and right positions via a thermal insulation section 13.

FIG. 2 shows an example of a mounting structure of an electronic circuit on the circuit board P. In this example, there are two electronic circuits in which a high heat generating substrate portion 11 and a low heat generating substrate portion 12 are combined. It has been incorporated. The electronic circuits are connected to the low heat generation substrate unit 1 through the wiring 15 from the input terminal 14, respectively.
2. A signal is input to a low-heat-generating electronic circuit such as an integrated circuit incorporated in 2, and an output signal from this low-heat-generating electronic circuit is a high-heat-generating electronic circuit such as a power transistor incorporated in the high-heat generating substrate 11 through the wiring 16. The output signal from the high heat generating electronic circuit is input to the circuit and is output to the output terminal 1 through the wiring 17.
8 is output.

The heat insulating portion 13 has a main purpose of blocking the flow of heat from the high heat generating substrate portion 11 to the low heat generating substrate portion 12, and can have various configurations depending on the required heat flow inhibiting performance. . If the required performance is not strict, it is possible to use the thermal resistance of the circuit board P itself to form the thermal insulation portion 13. That is, the heat insulating portion 13 may be provided with a predetermined space between the high heat generating substrate portion 11 and the low heat generating substrate portion 12.

In such a mounting structure, the high heat generation substrate portion 11
The heat flow from the low heat generation substrate section 12 to the low heat generation substrate section 12 is blocked by the heat insulation section 13, and even when the circuit board P of the electronic device of the mounting structure according to the present invention is erected and vertically mounted in a plurality of stages, the circuit board P Another circuit board P is provided below the low heat generation board portion 12 in the inside.
The high heat generation substrate section 11 in the inside is not arranged. Therefore, high temperature air after cooling the high heat generation substrate section 11 flows into the low heat generation substrate section 12 in the upper circuit board P and is provided below. The heat generated by the high heat generation board portion 11 in the circuit board P is
The low heat generation substrate portion 12 in the circuit board P provided above is not affected.

FIG. 3 is a diagram showing a second embodiment of the present invention.
is there. Circuit board P₁, P₂, P₃Are also shown in Fig. 1, respectively.
Similarly to the above, the thermal insulation part 13₁, 13₂, 13₃Through
On the right side of the figure, the high heat generation substrate section₁, 11₂, 11₃Is arranged
The low heat generation substrate portion 12 is shown on the left side of the drawing.₁, 12₂, 12₃
Are arranged. 19 is a ventilation duct
In the figure, circuit boards P arranged in three stages₁，
P₂, P₃Each low heat generation substrate section 12₁, 12₂, 12₃To
It is configured to introduce wind. The ventilation duct 1
9 is the circuit board P₁, P₂, P₃Low heat generation inside
12₁, 12₂, 12 ₃Through the heat insulating layer 20 on the side of the
It is provided.

Further, in this embodiment, the circuit board P₁，
P₂, P₃Are arranged vertically in three stages to form one block
And the circuit board P at the top of the block₃Low heat-generating group
Board 12 ₃Above the ventilation duct 19 and above
Circuit board P of block of steps_FourThermal insulation part 13_FourAcross
An inclined convection guide plate 21 is provided. Also, the above
Circuit board P at the bottom of the block₁And the lower block
A convection guide plate 21 similar to the above is provided between the circuit board and
Has been.

A fan 22 ₁ is provided as a forced air cooling means at the lower entrance of the ventilation duct 19, and a fan 22 ₂ is also provided as a forced air cooling means below the high heat generating substrate portion of the lowermost block. There is. The fan 22 ₁
The air that has been sent in and is guided to the ventilation duct 19 flows in through the opening 23 between the convection guide plate 21 and the circuit board P ₁ and passes through the low heat generation board sections 12 ₁ , 12 ₂ , and 12 ₃ . It is cooled, guided by the convection guide plate 21 above the low heat generating substrate portion 12 ₃ , and discharged to the high heat generating substrate portion. Such a wind flow is indicated by an arrow A. The cooling air also flows through the circuit boards of the blocks arranged in multiple stages in the same manner as described above.

The heat insulating layer 20 provided between the circuit boards P ₁ , P ₂ and P ₃ and the ventilation duct 19 includes the ventilation duct 1
It has an effect of preventing the temperature of the cool air inside 9 from rising due to heat conduction from the circuit boards P ₁ , P ₂ , P ₃ .
The heat insulating layer 20 can also be used as a housing of the connector, a mother board, or the like. The fans 22 ₁ and 22 ₂ as the forced air cooling means include the circuit boards P ₁ and P 2.
₂ , provided as necessary to force convection of air flowing into P ₃ . In addition, the circuit board P ₁ ,
High heat generating substrate parts 11 ₁ , 11 ₂ , on the other side of P ₂ , P ₃ ,
The 11 ₃ side may have an open structure, and a ventilation duct may be added similarly to the low heat generating substrate sections 12 ₁ , 12 ₂ , 12 ₃ side. Further, instead of the ventilation duct, the high heat generation substrate parts 11 ₁ , 11 ₂ , 11 ₃ and the low heat generation substrate parts 12 ₁ , 1
The side surfaces of 2 ₂ and 12 ₃ are hermetically sealed to have a chimney structure so that the air flowing through the high heat generating substrate section and the low heat generating substrate section sequentially flows to the high heat generating substrate section and the low heat generating substrate section above it.
A single fan may be provided by adopting a so-called pull type or negative pressure type in which a fan is provided above the chimney structure.

As is clear from the above description, in this embodiment, in addition to eliminating the influence of heat between the circuit boards of each block, the heat flow passages are divided into the low heat generating board portion and the high heat generating board portion. Since they can be separated, the optimum design can be made for each circuit board, and the electronic device can be downsized and high-density mounted.

FIG. 4 is a perspective view of the third embodiment of the present invention. The high heat generation substrate portion 11 and the low heat generation substrate portion 12 are arranged at the left and right positions, and the partition wall 24 is provided at the position of the heat insulating portion 13 between them. The partition wall 24 is for preventing the air streams of the high heat generation substrate portion 11 and the low heat generation substrate portion 12 from being mixed with each other, and the high heat generation substrate portion 11 is formed.
It is possible to surely prevent the heat flow of (1) from entering the low heat generation substrate section 12 and raising the temperature of the low heat generation substrate section 12. When forced air cooling is performed as described above, the partition wall 24 is particularly effective because the air flow is turbulent and mixing easily occurs. The height of the partition wall 24 is selected so that the gap between the adjacent circuit boards and the like is minimized.

FIG. 5 is a perspective view of the fourth embodiment of the present invention. The high heat generation substrate portion 11 and the low heat generation substrate portion 12 are arranged at left and right positions, a partition wall 24 is provided between them, and the high heat generation substrate portion 11 is provided with a heat dissipation member 25. It is important for the high heat generation substrate section 11 to efficiently dissipate heat and suppress the temperature rise of the electronic components mounted therein, and it is effective to reduce the thermal resistance between the high heat generation substrate section 11 and the air. is there. Therefore, by disposing the heat dissipating member 25 on the high heat generating substrate portion 11, the contact area between the heat dissipating member 25 and the air is increased, heat is efficiently dissipated, and the high heat generating substrate portion 11 is effectively cooled.

FIG. 6 is a perspective view of the fifth embodiment of the present invention. This circuit board P is configured by using a circuit board material of the high heat generation board portion 11 by using a good heat conductive board such as a metal core printed wiring board or a ceramic board. The good thermal conductive substrate has an effect of averaging the temperature of each part in the substrate by its good thermal conductivity, and has an effect of preventing local temperature rise. Further, this good heat conducting substrate can also act as a heat radiating member, and particularly when a metal core printed wiring board is used, the moldability is good and an arbitrary shape can be realized.

FIG. 7 is a perspective view of the sixth embodiment of the present invention. In this circuit board P, the low heat generation board section 12 and the high heat generation board section 11 are made of different circuit boards, and when joining the both in the left-right direction, a washer 26 is interposed between the joint sections to attach the bolt 27. By joining with the nut 28 and the nut 28, a gap having the thickness of the washer 26 is formed between the heat generating substrate portions 11 and 12 to form a heat insulating portion. Here, a good heat conductive substrate is used as the high heat generating substrate portion 11, and the low heat generating substrate portion 12 is coupled with a gap therebetween. Washer 26, bolt 27, nut 28
As for the above, if a plastic material having a large heat resistance is used, the heat insulation effect will be more reliable.

FIG. 8 is a perspective view of the seventh embodiment of the present invention. In this circuit board P, the high heat generation board section 11 and the low heat generation board section 12 are formed of different boards, and when joining the both in the left-right direction, a cutout section 12a is formed in the low heat generation board section 12. The bolt 27 and the nut 28 are joined together to form a gap by the cutout portion 12a to form a heat insulating portion.

FIG. 9 is a perspective view of the eighth embodiment of the present invention. In this circuit board P, a plurality of holes 29 are formed in the heat insulation part 13 between the low heat generation board part 12 and the high heat generation board part 11.
Is formed, and the hole 29 forms a gap. The heat resistance of the portion of the hole 29 becomes large, and the flow of heat between the high heat generation substrate portion 11 and the low heat generation substrate portion 12 is suppressed. The shape of the hole 29 is not limited to a circle and may be any shape.

[0026]

As described above, in the mounting structure of the electronic device, the circuit board on which the electronic circuit of the electronic device is mounted is erected in the vertical direction on the frame body. The board portion and the low heat generating board portion on which the low heat generating electronic circuit is mounted are classified, and the high heat generating board portion and the low heat generating board portion are
Since it is arranged in the left-right direction via the thermal insulation part,
Even when a plurality of circuit boards are vertically mounted in multiple stages, the high heat generating board portion is not arranged below the low heat generating board portion, and therefore, the high temperature air after cooling the high heat generating board portion is low. It is possible to prevent the heat from flowing into the heat generating substrate. Further, since the low heat generation board part and the high heat generation board part in the single circuit board are arranged via the heat insulation part, it is possible to reduce the flow of heat from the high heat generation board part to the low heat generation board part. You can Further, even if a plurality of circuit boards are installed upright in multiple stages, it is not necessary to provide a convection guide plate between the circuit boards, and a stack of several circuit boards constitutes one block. The convection guide plate may be provided above the uppermost circuit board of the block, and the mounting density of the electronic device can be increased as a whole. Further, it is possible to optimize the thermal design of each of the high heat generation substrate portion and the low heat generation substrate portion in accordance with the temperature condition of the electronic circuit element forming the electronic circuit, which enables high-density mounting of the electronic device. Further, even when a plurality of electronic circuits are mounted on a single circuit board, each electronic circuit is formed by connecting the low heat generation board section and the high heat generation board section arranged at the left and right positions. Interlocking of connections between electronic circuits is eliminated. The overall effect of these is that the electronic device as a whole can be made compact and high-density mounted.

[Brief description of drawings]

FIG. 1 is a front view for explaining a first embodiment of the present invention.

FIG. 2 is a diagram showing an example of a mounting structure of an electronic circuit on a circuit board applied to the present invention.

FIG. 3 is a diagram for explaining a second embodiment of the present invention.

FIG. 4 is a perspective view for explaining a third embodiment of the present invention.

FIG. 5 is a perspective view for explaining a fourth embodiment of the present invention.

FIG. 6 is a perspective view for explaining a fifth embodiment of the present invention.

FIG. 7 is a perspective view for explaining a sixth embodiment of the present invention.

FIG. 8 is a perspective view for explaining a seventh embodiment of the present invention.

FIG. 9 is a perspective view for explaining an eighth embodiment of the present invention.

FIG. 10 is a front view for explaining a mounting structure of a conventional electronic device.

FIG. 11 is a diagram showing an example of a conventional electronic circuit mounting structure on a circuit board.

FIG. 12 is a front view illustrating a case where a conventional electronic device is vertically mounted in a plurality of stages.

[Explanation of symbols]

1 high heat generation substrate part 2 low heat generation substrate part 3 input terminal 4 wiring 5 wiring 6 wiring 7 output terminal 8 convection induction plate 11 high heat generation substrate part 12 low heat generation substrate part 13 thermal insulation part 14 input terminal 15 wiring 16 wiring 17 wiring 18 Output terminal 19 Ventilation duct 20 Thermal insulation layer 21 Convection guide plate 22 ₁ Fan 22 ₂ Fan 23 Opening 24 Partition wall 25 Heat dissipation member 26 Washer 27 Bolt 28 Nut 29 Hole

Claims (8)

[Claims] 1. A mounting structure of an electronic device in which a circuit board on which an electronic circuit of an electronic device is mounted is erected in a vertical direction on a frame, wherein a high-heat-generating substrate part on which a high-heat-generating electronic circuit is mounted and low heat generation are provided. The electronic device is characterized by being divided into a low-heat-generating substrate part on which an electronic circuit is mounted, and the high-heat-generating substrate part and the low-heat-generating substrate part are arranged at left and right positions via a heat insulating part. Mounting structure. 2. A circuit board on which an electronic circuit of an electronic device is mounted is divided into a high-heat-generating board part on which a high-heat-generating electronic circuit is mounted and a low-heat-generating board part on which a low-heat-generating electronic circuit is mounted. Section and the low heat generation board section are arranged in the left and right direction positions via the heat insulation section, and are erected in a vertical direction on the frame body to be mounted in multiple stages, and the high heat generation board section of these circuit boards or A mounting structure for an electronic device, characterized in that a ventilation duct is provided so as to introduce cooling air into either one of the low heat generation substrate portions. 3. A plurality of circuit boards, in which a high-heat-generating board portion and a low-heat-generating board portion are disposed at right and left positions via the thermal insulation portion, are vertically installed in a vertical direction to be mounted in multiple stages, and the uppermost stage is mounted. 3. A convection guide plate is obliquely provided on an upper portion of the low heat generating substrate portion in the circuit board, and the rising air that has cooled the low heat generating substrate portion is guided to the high heat generating substrate portion. The mounting structure of the described electronic device. 4. The mounting of the electronic device according to claim 2, wherein the ventilation duct is provided on a side portion of the high heat generation substrate section or the low heat generation substrate section in the circuit board via a heat insulating layer. Construction. 5. A high heat generating substrate portion and // in the circuit substrate.
3. The mounting structure for an electronic device according to claim 1, further comprising a forced air cooling unit for forcibly introducing cooling air to the low heat generation substrate section. 6. A partition is provided in a heat insulating portion between the high heat generating substrate portion and the low heat generating substrate portion.
Alternatively, the mounting structure of the electronic device according to 2. 7. The mounting structure for an electronic device according to claim 1, wherein a heat dissipation member is provided on the high heat generation substrate portion. 8. The mounting structure for an electronic device according to claim 1, wherein a gap is formed between the high heat generating substrate portion and the low heat generating substrate portion to form a heat insulating portion.