JP6982987B2 - Board assembly - Google Patents

Description

The present invention relates to a substrate assembly using a printed circuit board used in an electronic device.

Conventionally, in electronic devices mounted on moving bodies such as trains and automobiles, printed circuit boards are mounted so as to withstand external vibrations and shocks. Patent Document 1 discloses a technique for reducing the overall weight while maintaining structural strength even when a large number of printed circuit boards are mounted on electronic devices.

Japanese Unexamined Patent Publication No. 2005-197493

However, according to the above-mentioned conventional technique, six printed circuit boards are combined in a box shape, and the internal space surrounded by the printed circuit boards is closed. Therefore, in the printed circuit board, when a heat generating component such as a power transistor is mounted on the part corresponding to the inner surface surrounded by the six printed circuit boards, the temperature of the internal space rises and it is in the internal space. There was a problem that the life of the parts was shortened.

The present invention has been made in view of the above, and an object of the present invention is to obtain a substrate assembly capable of dissipating heat from heat-generating components while maintaining structural strength.

In order to solve the above-mentioned problems and achieve the object, the substrate assembly of the present invention has a cylindrical body having a polygonal cross section formed by combining three or more printed circuit boards and a vertical direction of the tubular body. It is provided with two reinforcing materials, which are attached to the upper end portion and the lower end portion of the above, and are plate-shaped and have an opening serving as a ventilation port. On one or more printed circuit boards out of three or more printed circuit boards, heat-generating components are mounted on the inner wall surface side of the cylindrical body, and on one or more printed circuit boards, the heat-generating components are mounted from the lower end of the cylindrical body. The shape of the polygon is rectangular, and the vertical length of the cylinder is longer than the length of the sides of the rectangle . It is characterized in that the space inside the tubular body is provided with an adjusting material for adjusting the cross-sectional area of the tubular body and the volume of the hollow portion .

According to the present invention, the substrate assembly has the effect of being able to dissipate heat from heat-generating components while maintaining structural strength.

A perspective view showing a configuration example of the substrate assembly according to the first embodiment. A perspective view showing a state in which the upper reinforcing material is removed from the tubular body in the substrate assembly according to the first embodiment. A perspective view showing a state in which the front board is removed from the tubular body of the board assembly according to the first embodiment. Schematic diagram showing the state of air convection in the substrate assembly according to the first embodiment. A perspective view for explaining the shape of the cylindrical body according to the first embodiment. A perspective view showing an example of the arrangement of the adjusting material installed in the substrate assembly according to the first embodiment. A perspective view showing a configuration example of the substrate assembly according to the second embodiment. A perspective view showing another configuration example of the substrate assembly according to the second embodiment.

Hereinafter, the substrate assembly according to the embodiment of the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment.

Embodiment 1.
FIG. 1 is a perspective view showing a configuration example of the substrate assembly 100 according to the first embodiment of the present invention. Further, FIG. 2 is a perspective view showing a state in which the upper reinforcing member 7 is removed from the tubular body 200 in the substrate assembly 100 according to the first embodiment. Further, FIG. 3 is a perspective view showing a state in which the front substrate 1 is removed from the cylindrical body 200 of the substrate assembly 100 according to the first embodiment. In FIGS. 1 to 3, the direction in which the component surfaces or solder surfaces of the main boards 2 and 3 face each other is the X-axis direction, which is the direction perpendicular to the X-axis direction in the horizontal plane and is the solder surface of the front board 1 and the back board 4. The direction in which they face each other is the Y-axis direction, and the X-axis direction and the direction perpendicular to the Y-axis direction are the Z-axis directions. The substrate assembly 100 is composed of a tubular body 200 and a reinforcing material 7. Although not shown in FIGS. 1 to 3, it is assumed that the reinforcing material 7 is also attached to the lower side of the tubular body 200 in the substrate assembly 100. The tubular body 200 is composed of a front substrate 1, main substrates 2 and 3, and a back substrate 4. The front board 1, the main boards 2 and 3, and the back board 4 are printed circuit boards mounted on electronic devices.

The front board 1 includes two bottom entry connectors 5 for connecting to the main boards 2 and 3. The front board 1 is provided with a slit or a hole in the bottom portion of the bottom entry connector 5. This slit or punch hole is for passing a pin from the pinhead connector 6 of the main boards 2 and 3 connected to the bottom entry connector 5 in the Y-axis direction. The bottom entry connector 5 is a connector in which a pin can be inserted even from the bottom surface, as opposed to a general connector in which a pin can be inserted only from the top surface side. The front board 1 has a hole 11 for passing a screw 12 for attaching the reinforcing material 7. In the front board 1, the surface on which the bottom entry connector 5 is mounted is a component surface, and the surface opposite to the component surface is a solder surface. Although omitted in FIGS. 1 to 3, it is assumed that components other than the bottom entry connector 5 are mounted on the front board 1. In the front board 1, components can be mounted on the solder surface as well.

The main board 2 includes a pin head connector 6 for connecting to the front board 1 in the Y-axis direction and a pin head connector 6 for connecting to the back board 4 in the Y-axis direction. In the main board 2, one pin head connector 6 is arranged on the front board 1 side of the component surface so that the pin faces perpendicular to the front board 1 in the Y-axis direction, and the other pin head connector 6 has the pin in the Y-axis direction. It is arranged on the back board 4 side of the component surface so as to face vertically to the back board 4. In the main board 2, the pinhead connector 6 is arranged within 10 mm from the board end so that the pin protrudes from the board end. The main board 2 has a hole 11 for passing a screw 12 for attaching the reinforcing material 7. In the main board 2, the surface on which the pinhead connector 6 is mounted is a component surface, and the surface opposite to the component surface is a solder surface. Although omitted in FIGS. 1 to 3, it is assumed that components other than the pinhead connector 6 are mounted on the main board 2. In the main board 2, components can be mounted on the solder surface as well.

The main board 3 includes a pin head connector 6 for connecting to the front board 1 in the Y-axis direction and a pin head connector 6 for connecting to the back board 4 in the Y-axis direction. The arrangement pattern of the pinhead connector 6 on the main board 3 is the same as that of the main board 2 described above. The main board 3 has a hole 11 for passing a screw 12 for attaching the reinforcing material 7. In the main board 3, the surface on which the pinhead connector 6 is mounted is a component surface, and the surface opposite to the component surface is a solder surface. Although omitted in FIGS. 1 to 3, it is assumed that components other than the pinhead connector 6 are mounted on the main board 3. In the main board 3, components can be mounted on the solder surface as well.

Although not shown in FIGS. 1 to 3, the back board 4 includes two bottom entry connectors 5 for connecting to the main boards 2 and 3. The back board 4 is provided with a slit or a hole in the bottom portion of the bottom entry connector 5. This slit or punch hole is for passing a pin from the pinhead connector 6 of the main boards 2 and 3 connected to the bottom entry connector 5 in the Y-axis direction. The bottom entry connector 5 used in the back board 4 is the same as the bottom entry connector 5 used in the front board 1. The back board 4 has a hole 11 for passing a screw 12 for attaching the reinforcing material 7. In the back board 4, the surface on which the bottom entry connector 5 is mounted is a component surface, and the surface opposite to the component surface is a solder surface. Although omitted in FIGS. 1 to 3, it is assumed that components other than the bottom entry connector 5 are mounted on the back board 4. In the back board 4, components can be mounted on the solder surface as well.

The tubular body 200 is a tubular body having a polygonal cross section formed by combining four printed circuit boards, specifically, a front substrate 1, a main substrate 2, 3 and a back substrate 4. In the tubular body 200, the main boards 2 and 3 are arranged in the direction perpendicular to the front board 1 and in the Y-axis direction in FIG. 1 and the like. Further, the back substrate 4 is arranged in the vertical direction with respect to the main substrates 2 and 3 on the side opposite to the side connected to the front substrate 1, and in the Y-axis direction in FIG. 1 and the like. When connecting the main boards 2 and 3 and the front board 1, the pins of the pinhead connectors 6 of the main boards 2 and 3 are placed on the front board 1 from the surface opposite to the surface on which the bottom entry connector 5 is arranged in the Y-axis direction. , Insert into the bottom entry connector 5. Similarly, when connecting the main boards 2 and 3 and the back board 4, the pins of the pinhead connectors 6 of the main boards 2 and 3 are opposite to the surface of the back board 4 where the bottom entry connector 5 is arranged in the Y-axis direction. It is inserted into the bottom entry connector 5 from the surface of.

In the tubular body 200, the front board 1 and the main boards 2 and 3 are in contact with each other, or the distance between the front board 1 and the main boards 2 and 3 is 5 mm or less, so that the front board 1 and the main boards 2 and 3 are in contact with each other. However, it is arranged three-dimensionally while ensuring electrical continuity. Similarly, in the tubular body 200, the back substrate 4 and the main substrate 2 and 3 are in contact with each other, or the distance between the back substrate 4 and the main substrates 2 and 3 is 5 mm or less, so that the back substrate 4 and the main substrate 2 and 3 are in contact with each other. A few are arranged three-dimensionally while ensuring electrical continuity. By using the bottom entry connector 5 and the pinhead connector 6, the tubular body 200 has a three-dimensional shape in which the front board 1, the main boards 2 and 3, and the back board 4 are combined. The distance of 5 mm shown as the distance between the printed circuit boards is an example, and may be a value different depending on the pin length of the pin head connector 6. In the tubular body 200, the area of the printed circuit board on which the components can be mounted can be increased by arranging such a three-dimensional printed circuit board.

Regarding the orientation of the main boards 2 and 3 of the tubular body 200, the right side is the component surface and the left side is the solder surface in FIG. 3, but this is just an example, and the component surfaces of the main boards 2 and 3 are both tubular bodies. It may be configured to face the inside of the 200, or the component surfaces of the main boards 2 and 3 may all face the outside of the tubular body 200. In the examples of FIGS. 1 to 3, a part of the front substrate 1 and the back substrate 4 has a shape protruding from the cylindrical portion, but this is an example, and the present invention is not limited thereto. In the tubular body 200, if the solder surface of the main boards 2 and 3, that is, the surface on which the pinhead connector 6 is mounted is configured to face the inside of the tubular body 200, the front board 1 and the back board 4 are tubular. It is also possible to eliminate the part that protrudes from the part.

The reinforcing material 7 is for maintaining the shape of the tubular body 200, that is, the arrangement of each printed circuit board in a state where the front board 1, the main boards 2, 3 and the back board 4 are combined. The shape of the reinforcing material 7 when viewed from the Z-axis direction is the same as the shape of the inner wall portion in the cross section when the tubular body 200 is cut in the XY plane. The reinforcing material 7 is made of a general metal, for example, stainless steel. The reinforcing material 7 has a hole 8 for passing air through a hollow portion which is a space inside the tubular body 200. The hole 8 is an opening that serves as a ventilation port for air in the hollow portion of the tubular body 200. Further, the reinforcing material 7 has a screw hole 9 for fixing to the front board 1, the main boards 2 and 3, and the back board 4. Further, the reinforcing material 7 has a screw hole 10 for fixing the board assembly 100 to the electric device on which the board assembly 100 is mounted. In FIG. 2, the shape of the reinforcing material 7 is an example in which the end of the plate-shaped material is bent and a screw hole 9 is provided in the bent portion, but the shape is not limited to this. The reinforcing material 7 may be generated from a rectangular parallelepiped-shaped material having a thickness larger than the diameter of the screw hole 9.

In the substrate assembly 100, 1 is formed on the inner wall surface of the upper end portion of each printed circuit board and the inner wall surface of the lower end portion (not shown) in the Z-axis direction in the example of FIG. Reinforcing materials 7 are attached one by one. The reinforcing material 7 and each printed circuit board are fixed by driving screws 12 into the screw holes 9 of the reinforcing material 7 from the outside of each printed circuit board through the holes 11. The screw 12 may be made of resin or metal. The substrate assembly 100 is improved in rigidity by fixing the tubular body 200 in which each printed circuit board is three-dimensionally arranged to the reinforcing material 7, and the proof stress against instantaneous tensile and compressive stress is improved.

In the present embodiment, the substrate assembly 100 can increase the surface area of the printed circuit board per unit volume by arranging the printed circuit boards in three dimensions as shown in FIG. 1, and the printed circuit boards are not arranged in three dimensions. Many components can be mounted on a printed circuit board. In the substrate assembly 100, since the volume required for mounting the component on the printed circuit board can be reduced, the device on which the substrate assembly 100 is mounted, that is, the electronic device can be miniaturized.

When an electronic device equipped with a substrate assembly 100 is used for a moving body such as a train or an automobile, the substrate assembly 100 is always exposed to a vibration environment. Further, when the board assembly 100 is attached to the moving body, stress is applied to the connector portion of the board assembly 100 (not shown). In general, vibration and stress decrease as the distance from the fulcrum decreases. The substrate assembly 100 is useful for suppressing vibration and stress because the distance from the point fixed to the electronic device, that is, the fulcrum to the edge of the printed circuit board can be shortened.

Further, in the present embodiment, the direction of the substrate assembly 100, that is, the tubular body 200 is set to be the direction in which the air flow through the hole 8 of the reinforcing material 7 is in the vertical direction, that is, in the Z-axis direction. In the substrate assembly 100, since the reinforcing material 7 has a hole 8, the space surrounded by each printed circuit board and the reinforcing material 7 is not sealed, so that the air inside can flow in and out. Here, in the substrate assembly 100, the convection of air generated in the hollow portion of the tubular body 200 will be described. FIG. 4 is a schematic view showing a state of air convection in the substrate assembly 100 according to the first embodiment. In FIG. 4, the description of the bottom entry connector 5, the pinhead connector 6, the reinforcing material 7, and the like is omitted so that the state of air convection in the substrate assembly 100 can be understood. Further, FIG. 4 shows an example in which the heat generating component 13 is mounted on the component surface of the main substrate 2, that is, on the hollow portion side surrounded by the four printed circuit boards of the cylindrical body 200. Further, in FIG. 4, the front board 1 and the main board 3 are shown in a transparent state so that the position of the heat generating component 13 of the main board 2 can be recognized. The heat generating component 13 corresponds to, for example, a regulator, a diode for amplification, a transistor, or the like. The heat generating component 13 may be mounted on the hollow portion side of the tubular body 200, that is, on the inner wall surface side in one or more of the four printed circuit boards.

In FIG. 4, the heat generating component 13 is mounted on the inner wall surface of the main board 2, that is, the tubular body 200 from the lower end portion of the center in the Z-axis direction, that is, the vertical direction, and the Z-axis of the main board 2, that is, the tubular body 200. An example is shown in which a component is not mounted on the upper end side of the center in the direction, that is, in the vertical direction, or a non-heat-generating component having a smaller heat generation amount than the heat-generating component 13 is mounted. In the hollow portion of the tubular body 200, when the front board 1, the main boards 2, 3 and the back board 4, that is, the four printed circuit boards are in operation, the ambient temperature is generated by the heat generated by the heat generating component 13 around the heat generating component 13. Increases, the density of air decreases, and a chimney effect that creates buoyancy occurs. In the substrate assembly 100, in the hollow portion of the tubular body 200, convection of air is generated in the Z-axis direction due to the updraft 21 due to the chimney effect. In the board assembly 100, since the reinforcing material 7 attached to the upper end portion and the lower end portion has a hollow hole 8, air can flow in and out of the hollow portion. In the substrate assembly 100, the farther the heat generating component 13 is toward the lower end of the tubular body 200, the longer the distance to the upper end, that is, the higher the chimney portion, and the more the chimney effect can be obtained.

In the substrate assembly 100, the updraft 21 generated by the chimney effect causes the cold air 22 on the outside to flow from the hole 8 of the reinforcing material 7 at the lower end, and the air 23 heated by the heat generating component 13 is at the upper end. It is released from the reinforcing material 7. Since high voltage and high current are used in a moving body such as a train or an automobile, or an electronic device mounted on the moving body, there is a problem that the product life is shortened due to the temperature rise due to the heat generating component 13. In the present embodiment, in the substrate assembly 100, the temperature rise of the heat generating component 13 is suppressed by the air flow in the Z-axis direction due to the cold air 22, the updraft 21 and the heated air 23 shown in FIG. , It is possible to suppress the temperature rise of the heat generating component 13, the peripheral component of the heat generating component 13, and each printed substrate, and to suppress the decrease of the component, that is, the product life.

Here, the shape of the tubular body 200 for effectively convection of air in the hollow portion by the chimney effect in the substrate assembly 100 will be described. FIG. 5 is a perspective view for explaining the shape of the tubular body 200 according to the first embodiment. In FIG. 5, for the sake of brevity, the parts mounted on each printed circuit board, the holes 11 and the like are omitted. Further, in order to simplify the explanation, in FIG. 5, the reinforcing material 7 is removed. Generally, if the height of the hollow portion that becomes the chimney in the Z-axis direction is low with respect to the cross-sectional area of the inner wall surface of the tubular body 200 in the cross section of the XY plane, convection of air is less likely to occur, and rather the inside. There is a risk that the heat will be trapped. Here, since the shape of the cross-sectional area of the XY plane of the inner wall surface of the tubular body 200 is rectangular, in the cross-sectional area of the XY plane of the inner wall surface of the tubular body 200, the portions of the front substrate 1 and the back substrate 4 Let a be the length, b be the length of the parts of the main boards 2 and 3, and h be the height of the cylindrical body 200 in the Z-axis direction when placed as shown in FIG. 5, that is, the length of the chimney part. Then, it is desirable that "h ≧ a", "h ≧ b", "a> 0", and "b> 0". In the chimney effect, the air flow in the chimney portion can generally be expressed as the equation (1).

In equation (1), Q is the air supply speed due to the chimney effect (m ³ / s), A is the cross-sectional area of the chimney (m ² ), C is the flow coefficient, g is the gravitational acceleration (m / s ² ), and h is. chimney height (m), is T _o is the ambient air absolute temperature (K), T _i is the average temperature in the chimney (K). The flow coefficient C is usually 0.65 to 0.7, and the gravitational acceleration g = 9.80665 (m / s ² ). The cross-sectional area A of the chimney is the cross-sectional area of the air outlet portion, and is the area of the hole 8 of the reinforcing material 7 in the actual substrate assembly 100. When there are a plurality of holes 8, the total area of all the holes 8 is the cross-sectional area A of the chimney. The user can determine the size of the tubular body 200 and the size of the hollow hole 8 of the reinforcing material 7 in consideration of the temperature of the heat generating component 13 to be used.

As described above, according to the present embodiment, in the substrate assembly 100, a reinforcing material 7 having a hole 8 is attached to the upper end portion and the lower end portion of the tubular body 200 in the Z-axis direction, and the tubular body is formed. Due to the heat generated by the heat generating component 13 mounted on the inner wall surface side of the printed circuit board constituting the 200, convection of air is generated in the vertical direction, that is, in the Z-axis direction due to the updraft due to the chimney effect in the hollow portion. As a result, the substrate assembly 100 can effectively dissipate heat from the heat generating component 13 by convection of air while maintaining the structural strength.

In the present embodiment, the bottom entry connector 5 and the pinhead connector 6 are used for the connection between the front board 1 and the main boards 2 and 3 and the connection between the back board 4 and the main boards 2 and 3, but this is an example. However, the connectors used for connecting the printed circuit boards are not limited to these. For example, the bottom entry connector 5 and the pinhead connector 6 are used for connecting the front board 1 and the main boards 2 and 3, and a general connector is used for connecting the back board 4 and the main boards 2 and 3 as described above. For example, a right angle connector or a card edge connector may be used.

Further, even if the bottom entry connector 5 and the pinhead connector 6 are used for connecting the front board 1 and the main boards 2 and 3 as described above, and the back board 4 and the main boards 2 and 3 are connected by soldering. good. Regarding soldering between printed circuit boards, specifically, a slit is provided in the back substrate 4, and electrodes are provided on both sides of the slit. Convex protrusions are provided on the main boards 2 and 3, and electrodes are provided on the protrusions. The protrusions of the main boards 2 and 3 are inserted into the slits of the back board 4, and the electrodes of the back board 4 and the electrodes of the main boards 2 and 3 are electrically connected by flow soldering. At the time of this flow soldering, it is possible to suppress the misalignment and inclination of the main boards 2 and 3 by flowing the reinforcing material 7 with the reinforcing material 7 attached. If the back board 4 and the main boards 2 and 3 are connected by flow soldering first, then when the reinforcing material 7 is attached to each printed circuit board using the screw 12, stress is applied to each printed circuit board and soldered. Cracks are likely to occur in the soldered electrode portion. Therefore, the reinforcing material 7 is attached before the flow soldering. As for the connection between the front board 1 and the main boards 2 and 3, flow soldering may be used in the same manner as the connection between the back board 4 and the main boards 2 and 3.

Further, in the present embodiment, the shape of the cylindrical body 200 is the shape of a cylindrical quadrangular prism using four printed circuit boards of the front substrate 1, the main substrate 2, 3 and the back substrate 4. The shape of the tubular body 200 is not limited to this. As for the tubular body 200, if there are at least three printed circuit boards, the printed circuit boards are combined to form a three-dimensionally polygonal cylindrical body. Specifically, the tubular body 200 can be formed into a tubular triangular prism shape by using three printed circuit boards. Further, the tubular body 200 can be formed into a tubular pentagonal prism shape by using five printed circuit boards. The same applies when using six or more printed circuit boards. Therefore, if there is a connector that can connect each printed circuit board at an angle other than vertical, or if there is a soldering method, it is possible to change the shape of the tubular body 200 to a shape other than a tubular quadrangular prism. be. If the shape of the tubular body 200 can be made into a cylindrical triangular prism or the like, the shape of the reinforcing material 7 is also made to match the shape of the tubular body 200.

Further, in the present embodiment, the substrate assembly 100 is provided with an adjusting material for adjusting the cross-sectional area of the tubular body 200 and the volume of the hollow portion, and is adjusted to the hollow portion which is the space inside the tubular body 200. The material may be arranged. FIG. 6 is a perspective view showing an example of the arrangement of the adjusting material 14 installed in the substrate assembly 100 according to the first embodiment. Similar to FIG. 4, the description of the bottom entry connector 5, the pinhead connector 6, the reinforcing material 7, and the like is omitted. Further, in FIG. 6, the front substrate 1 and the main substrate 3 are shown in a transparent state so that the arrangement of the adjusting material 14 can be recognized. When the number of parts used in each printed circuit board of the cylindrical body 200 is large and the printed circuit board cannot be made small, the hollow portion of the tubular body 200, that is, the chimney portion can be substantially reduced by using the adjusting material 14. Can be transformed into. The material of the adjusting material 14 does not matter as long as it can withstand the heat generation temperature of the heat generating component 13. Regarding the method of fixing the adjusting material 14, the reinforcing material 7 may be fixed to the reinforcing material 7 by using a screw 12 or the like, or the adjusting material 14 may be fixed to any of the printed circuit boards constituting the tubular body 200 by using a screw 12 or the like. ..

Embodiment 2.
In the second embodiment, a fan is used to promote heat dissipation of the heat generating component 13. A part different from the first embodiment will be described.

FIG. 7 is a perspective view showing a configuration example of the substrate assembly 100a according to the second embodiment. In the substrate assembly 100a, the reinforcing material 7 at the upper end of the tubular body 200 is replaced with the reinforcing material 7a provided with the fan 15 with respect to the substrate assembly 100. In the substrate assembly 100a, the reinforcing material 7 at the lower end of the tubular body 200 may be replaced with the reinforcing material 7a, or the two reinforcing materials 7 at the upper end and the lower end of the tubular body 200 may be replaced with the reinforcing material 7a. May be replaced with. In the board assembly 100a, at least one of the two reinforcing materials is a reinforcing material 7a provided with a fan 15. The tubular body 200 is the same as that of the first embodiment.

The reinforcing material 7a includes a fan 15 and forcibly discharges the air inside the tubular body 200 to the outside. As a result, the substrate assembly 100a can effectively dissipate heat from the heat generating component 13 as compared with the substrate assembly 100. The electric power for driving the fan 15 may be supplied from any printed circuit board constituting the tubular body 200, or may be supplied from an electronic device on which the substrate assembly 100a is mounted. As for the reinforcing material 7a, if the size of the electronic device on which the substrate assembly 100a is mounted is acceptable, a fan may be added separately to the reinforcing material 7.

Since the fan 15 is used for the substrate assembly 100a, the heat generating component 13 can dissipate heat even if the chimney effect does not act. Therefore, it is also possible to use the substrate assembly 100a horizontally. FIG. 8 is a perspective view showing another configuration example of the substrate assembly 100b according to the second embodiment. The board assembly 100b is a horizontal arrangement of the board assembly 100a shown in FIG. 7, and the components of the board assembly 100b are the same as the components of the board assembly 100a. In the substrate assembly 100b, in the hollow portion of the tubular body 200, the air flow by the fan 15 of the reinforcing material 7a is in the horizontal direction.

As described above, according to the present embodiment, the substrate assembly 100a is provided with a fan, and the fan is used to promote convection of air in the hollow portion of the cylindrical body 200. As a result, the substrate assembly 100a can effectively dissipate heat from the heat generating component 13 as compared with the substrate assembly 100 of the first embodiment.

The configuration shown in the above-described embodiment shows an example of the content of the present invention, can be combined with another known technique, and is one of the configurations as long as it does not deviate from the gist of the present invention. It is also possible to omit or change the part.

1 front board, 2, 3 main board, 4 back board, 5 bottom entry connector, 6-pin head connector, 7,7a reinforcement, 8,11 hollow holes, 9,10 screw holes, 12 screws, 13 heat-generating parts, 14 adjustments Material, 15 fans, 100, 100a, 100b board assembly, 200 cylinders.

Claims (5)

A cylindrical body with a polygonal cross section formed by combining three or more printed circuit boards,
Two reinforcing materials that are attached to the upper and lower ends of the tubular body in the vertical direction and are plate-shaped and have an opening that serves as a ventilation port.
Equipped with
On one or more of the three or more printed circuit boards, heat-generating components are mounted on the inner wall surface side of the cylindrical body.
In the one or more printed circuit boards, the heat generating component is mounted from the lower end portion of the cylindrical body.
Wherein a cross-section polygonal shape rectangular, the length of the vertical direction of the tubular body, rather longer than the length of said rectangular sides,
The space inside the tubular body is provided with an adjusting material for adjusting the cross-sectional area of the tubular body and the volume of the hollow portion.
A board assembly characterized by that. A bottom entry connector and a pinhead connector are used to connect two of the three or more printed circuit boards.
The substrate assembly according to claim 1. A right angle connector is used to connect two printed circuit boards out of the three or more printed circuit boards.
The substrate assembly according to claim 1. A card edge connector is used to connect two printed circuit boards out of the three or more printed circuit boards.
The substrate assembly according to claim 1. Two of the three or more printed circuit boards are connected by soldering.
The substrate assembly according to claim 1.

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