JP2947598B2 - Printed wiring board and its cooling method - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed wiring board and a method for cooling the same, and more particularly, to a printed wiring board on which a plurality of semiconductor integrated circuit devices having a large amount of heat generation are mounted. The present invention relates to a printed wiring board capable of uniformly cooling a circuit device and improving the cooling efficiency of a plurality of semiconductor integrated circuit devices, and a technique effective when applied to a cooling method therefor.

[Prior Art] Conventionally, as a printed wiring board on which a semiconductor integrated circuit device is mounted, for example, a printed wiring board 2 on which a predetermined circuit is formed by mounting a plurality of semiconductor integrated circuit devices 1 as shown in FIG. In a console box of an electronic device (not shown), a plurality of such devices are stacked and stored in a multi-stage manner. Then, it is connected to an external device from the external connection terminal 3 via a connection wiring (not shown).

In this case, since the semiconductor integrated circuit device 1 mounted on the printed wiring board 2 generates heat in an energized state, for example, the cooling fan 4 is arranged in a horizontal direction with respect to the external connection terminal 3, that is, the printed wiring board 2. Of the semiconductor integrated circuit device 1 to prevent a characteristic change due to a rise in temperature.

In addition, as a technology similar to this, for example, “Industrial Research Institute Co., Ltd., published on January 15, 1980,
It is described in documents such as 11 to P240.

[Problems to be Solved by the Invention] However, in the above-described conventional technology, the air blowing pattern from the horizontal direction is disturbed due to the positional relationship of the semiconductor integrated circuit device mounted on the printed wiring board, and a plurality of semiconductor integrated circuits There is a problem that the device cannot be cooled uniformly. That is, in a semiconductor integrated circuit device in which the air volume is insufficient, the cooling may be insufficient.

Therefore, there is a problem that the high-density mounting of the semiconductor integrated circuit device on the printed wiring board is restricted, and at the same time, the heat generation margin of the semiconductor integrated circuit device is restricted so that the degree of freedom of design is reduced.

Therefore, an object of the present invention is to enable uniform cooling of components mounted on a printed wiring board, and to improve the cooling efficiency of each component, particularly in a printed wiring board on which a plurality of components generating a large amount of heat are mounted. An object of the present invention is to provide a printed wiring board and a method for cooling the same.

The above and other objects and novel features of the present invention are as follows.
It will be apparent from the description of this specification and the accompanying drawings.

[Means for Solving the Problems] Of the inventions disclosed in the present application, the outline of a representative one will be briefly described as follows.

That is, the printed wiring board of the present invention is a printed wiring board on which a plurality of components are mounted to form a predetermined circuit, and a cooling circuit is provided at an arbitrary position except a mounting portion of a plurality of components and a circuit forming portion. Are provided with a plurality of ventilation holes.

Further, a metal ring having a small thermal resistance is attached to the ventilation hole.

Further, the ventilation holes are formed by shaving off all portions except for the component mounting portion and the circuit forming portion.

Further, the cooling method of the printed wiring board of the present invention is characterized in that when a plurality of printed wiring boards having ventilation holes are arranged in a single or multiple stages, cooling air is supplied from a vertical direction to the printed wiring board. Is performed.

According to the above-described printed wiring board and its cooling method, a printed wiring board having a plurality of cooling ventilation holes at arbitrary positions except for a mounting part for a plurality of components and a formation part for a circuit. Are arranged in a single or multiple stages,
By sending cooling air from the vertical direction to the printed wiring board, the cooling air flows downward from the ventilation holes without disturbing the flow pattern and blows uniformly to one or more printed wiring boards At the same time, for each component mounted on each printed wiring board,
Uniform airflow is possible for each. Thereby, the cooling efficiency of a plurality of components can be improved.

Further, by attaching a metal ring having a small thermal resistance to the ventilation hole, the heat radiation effect of the printed wiring board can be improved. Thereby, the cooling efficiency can be further improved.

Furthermore, since the ventilation holes are cut and opened in all parts except for the component mounting part and the circuit forming part, the air flow to the component can be increased by reducing the ventilation resistance. Thereby, the cooling efficiency can be further improved.

Embodiment 1 FIG. 1 is a perspective view showing a printed wiring board according to an embodiment of the present invention, and FIGS. 2A and 2B are ventilation holes formed in the printed wiring board of the present embodiment. It is a perspective view which shows the deformation | transformation of.

First, the configuration of the printed wiring board of this embodiment will be described with reference to FIG.

The printed wiring board of the present embodiment is, for example, a printed wiring board 12 on which a plurality of semiconductor integrated circuit devices 11 as components are mounted to form a predetermined circuit, and external connection terminals connected to a circuit pattern (not shown). 13 is a printed wiring board
It is provided at one end of twelve.

The printed wiring board 12 includes a semiconductor integrated circuit device 11.
A plurality of ventilation holes 14 punched out on a cylinder are opened at arbitrary positions except for the mounting portion and the circuit pattern forming portion.

And the printed wiring board 12 configured as described above
Are stacked in a three-stage structure, for example, as shown in FIG. 1, and a cooling fan 15 is disposed on the upper surface thereof to blow air to the printed wiring board 12 from a vertical direction.

 Next, the operation of the present embodiment will be described.

Therefore, according to the printed wiring board 12 of the present embodiment, a plurality of ventilation holes 14 are opened in the printed wiring board 12, and air is blown from the vertical direction to the printed wiring boards 12 stacked in a three-stage structure. This allows the air blown from the cooling fan 15 to pass through the ventilation holes 14 downward without disturbing the flow pattern, and to blow air uniformly to each printed wiring board 12.

At the same time, uniform air can be sent to each of the semiconductor integrated circuit devices 11 mounted on the printed wiring board 12, so that the cooling efficiency can be improved.

In this case, by providing the ventilation holes 14 directly below the semiconductor integrated circuit device 11 is mounted, it is possible to further improve the cooling efficiency.

Further, the ventilation holes 14 formed in the printed wiring board 12 are opened in a star shape as shown in FIG. 2 (a) to increase the surface area of the ventilation holes 14, thereby improving the heat radiation efficiency. Also, as shown in FIG. 2 (b), the cooling efficiency can be similarly improved by attaching the metal ring 16 having a high heat radiation effect to the ventilation hole 14.

Embodiment 2 FIG. 3 is a perspective view showing a printed wiring board according to another embodiment of the present invention.

The printed wiring board of the present embodiment is, for example, a printed wiring board 12 on which a plurality of semiconductor integrated circuit devices 11 as components are mounted and a predetermined circuit is formed as in the first embodiment.
The difference from the first embodiment is that, as shown in FIG. 3, all parts except the mounting part of the semiconductor integrated circuit device 11 and the part where the circuit pattern is formed are cut off, and the printed wiring board 12 having a mesh shape is removed.
The point is.

Therefore, according to the printed wiring board 12 of the present embodiment, only the circuit pattern and the insulating layer that insulates the circuit pattern are left in the form of a mesh, and the other portions are opened as cooling ventilation holes 14, thereby realizing the implementation. The blowing resistance is reduced as compared with Example 1,
The cooling efficiency can be further improved by increasing the air volume.

As described above, the invention made by the inventor has been specifically described based on Embodiments 1 and 2. However, the present invention is not limited to each of the above-described embodiments, and can be variously modified without departing from the gist thereof. Needless to say, there is.

For example, for the printed wiring board 12 of the first embodiment,
The case where the ventilation hole 14 is punched out on a cylinder, or a modified example in which a large surface area is formed by opening a star shape has been described, but the present invention is not limited to the above-described embodiment. Other shapes such as a shape in which the vertices of a star are increased in order to further increase the surface area can be variously changed.

In the above description, the case where the invention made by the present inventor is mainly applied to the printed wiring board 12 on which the semiconductor integrated circuit device 11 having a large calorific value, which is the field of use, is applied is described. Not a thing,
For example, the present invention is widely applicable to printed wiring boards on which other components such as electronic components are mounted.

[Effects of the Invention] Of the inventions disclosed in the present application, effects obtained by typical ones will be briefly described as follows.

(1). A plurality of cooling ventilation holes are formed in the printed wiring board at arbitrary positions except for a mounting part of a plurality of parts and a formation part of a circuit, and a plurality of the printed wiring boards are arranged in a single or multi-stage shape. In this case, by sending cooling air to these printed wiring boards from the vertical direction, the cooling air flows downward through the ventilation holes without disturbing the flow pattern, and the cooling air is blown to one or more printed wiring boards. Air can be blown uniformly to each component, and at the same time, each component mounted on each printed wiring board can be blown uniformly, so that multiple components can be cooled uniformly. At the same time, the cooling efficiency of each component can be improved.

(2). By attaching a metal ring having a small thermal resistance to the ventilation hole, the heat radiation effect of the printed wiring board can be improved, so that the cooling efficiency can be further improved.

(3). By venting, all parts except the part mounting part and the circuit forming part are cut off and opened,
Since the air flow resistance of the printed wiring board is reduced and the air flow to each component can be increased, the cooling efficiency can be further improved.

(4). By the above (1) to (3), the cooling efficiency of the components is improved, so that a printed wiring board on which high-density and high-power-consumption components can be mounted can be obtained.

(5). By the above (1) to (3), it is possible to reduce the size of the cooling mechanism by improving the cooling efficiency, and to obtain a method for cooling a printed wiring board capable of reducing power consumption and reducing noise. .

(6). According to the above (1) to (3), it is possible to obtain a printed wiring board capable of improving a degree of freedom in circuit design without restricting a heat generation margin of a mounted component.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a printed wiring board according to a first embodiment of the present invention, and FIGS. 2 (a) and 2 (b) are perspective views showing deformation of ventilation holes formed in the printed wiring board according to the first embodiment. FIG. 3 is a perspective view showing a printed wiring board which is Embodiment 2 of the present invention. FIG. 4 is a perspective view showing an example of a conventional printed wiring board. 1 ... semiconductor integrated circuit device, 2 ... printed wiring board, 3
... external connection terminals, 4 ... cooling fans, 11 ... semiconductor integrated circuit devices (parts), 12 ... printed wiring boards, 13 ...
... external connection terminals, 14 ... ventilation holes, 15 ... cooling fans, 16 ... metal rings.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H05K 7/20 H05K 1/02

Claims (3)

(57) [Claims] 1. A printed wiring board on which a plurality of components are mounted to form a predetermined circuit, wherein a plurality of cooling circuits are provided at arbitrary positions except a mounting portion of the plurality of components and a formation portion of the circuit. A printed wiring board, characterized in that a ventilation hole is opened, and a metal ring having low thermal resistance is provided in the ventilation hole. 2. The printed wiring board according to claim 1, wherein all of the ventilation holes except for the mounting portion of the component and the forming portion of the circuit are cut off and opened. 3. The printed wiring board according to claim 1 or 2, wherein a plurality of printed wiring boards are arranged in a single or multi-stage manner, and cooling air is blown to the printed wiring board from a vertical direction. Plate cooling method.