JP5657260B2 - Circuit board heat dissipation structure - Google Patents

Description

  The present invention relates to a heat dissipation structure for more effectively releasing heat generated by circuit components mounted on a circuit board to the outside, and more specifically, heat dissipation of a circuit board that can achieve downsizing and energy saving. Concerning structure.

  Circuit board cooling methods include natural air cooling, water cooling, and forced air cooling using a fan.

  In order to perform water cooling, the structure must be waterproof and complicated. In addition, maintenance is required due to the generation of scale, which is expensive. Furthermore, when the circuit board is mounted on a vehicle, the vehicle is running with a part of the circuit board vulnerable due to a vehicle collision, and a part that is vulnerable for some reason is If it breaks, the coolant will leak, which can lead to serious accidents.

  For this reason, air cooling is preferred. Air cooling is performed by attaching a heat sink to the circuit components that need to be cooled, but the air heated by the heat transferred to the heat sink tends to stay in the heat sink, so that the fan is installed to ensure the effect. Used and forced air cooling. In other words, the heated air is forcibly exhausted by the fan. The fan is attached to a housing that accommodates a heat sink or a circuit board. However, the fan only stirs the heated air and the hot air diffuses. Moreover, in order to make the whole air flow and exhaust, the air volume must be large, and for that purpose, a larger fan is required. As a result, power consumption is increased and noise is increased.

  For this reason, in order to perform efficient heat dissipation when performing forced air cooling, the heat dissipation structure currently disclosed by the following patent document 1, for example was proposed.

  This heat dissipation structure is a structure in which a heat-generating component (heat-generating circuit component) and a heat-dissipating aluminum plate are covered with a heat-shielding member having a low thermal conductivity to form a tunnel-like space and heat is radiated by a heat-dissipating fan. That is, only air heated by the heat generating component is released.

Japanese Utility Model Publication No. 4-107890

  However, the heat-shielding member is formed in a substantially cylindrical shape, and heat generating components and aluminum plates are present in various cases therein. For this reason, compared with the case where the heat shield member is not provided, that is, when the entire inside of the housing is forcibly air-cooled, only the heated air can be discharged, and a large fan is not required and efficient heat dissipation can be performed. However, since there is a relatively large space in the heat shield member, the heated air is diffused in the relatively large space in the heat shield member by the wind generated by the fan. Further, since there are various heat generating parts and aluminum plates, the air flow is not uniform, and stagnation occurs. Since air has a large specific heat, it is difficult to warm at the beginning of heat generation, but once heated, it is difficult to cool down, and the heated air stays up, raising the temperature of circuit components, which is insufficient for heat dissipation. there were.

  Therefore, the main object of the present invention is to enable more effective heat dissipation while achieving miniaturization and energy saving.

The means for this is a circuit board heat dissipation structure for releasing heat generated from the circuit parts on the circuit board to the outside, and the circuit board mounted on the circuit board has a higher temperature than other circuit parts. as well as some of the circuit components that emit heat and high temperature circuit components constitute a high-temperature circuit part group of a plurality of high-temperature circuit components, together delimit the hot circuit part group from other circuit components, with the high temperature circuit component so as to form a space confined between the partition member is provided for covering the high-temperature circuit component group, the the partition member, together with the follow three-dimensional surface profile of the hot circuit part group, constitute the high-temperature circuit component group wherein between the high-temperature circuit components, it connects the outer periphery of the hot circuit part group is covered with the partition member linearly from the virtual outer circumferential line, and the hot circuit components enter enters the gap portion, the closing An outlet for discharging the air in the fit space, heat dissipation structure of a circuit board entrance is formed for flowing air into said containment space.

  The “enclosure” is different from a passage such as a tunnel and means to surround the periphery, and also includes covering the upper surface as necessary.

  The above-mentioned “entering / exiting according to the surface solid shape” means not a shape that extends linearly irrespective of the surface irregularities of the surface solid shape, but a shape that is recessed or bulged like the irregularities. The confining space is preferably as narrow (thin) as possible and has a small volume, although it does not just mean that the irregularities correspond to the irregularities or are faithful irregularities (perfectly similar shapes) conforming to the irregularities.

  In this heat dissipation structure, the circuit components are partitioned by a partition member to form a confinement space, so that air in the confinement space can flow between the inlet and the outlet and is heated by the heat generated by the circuit components. As soon as it is discharged to the outside from the outlet, air flows in from the inlet. That is, the air in the confinement space is quickly discharged outside without being diffused.

  In order to smoothly vent the confined space, a fan as a ventilation means may be used. The fan can be attached to the partition member, or can be attached to other parts and connected by a duct.

Still another means is a partition member used in the heat dissipation structure of the circuit board that covers a part of the circuit components in order to release heat generated from the circuit components on the circuit board to the outside, Among the circuit components mounted on the circuit board, a part of the circuit component that emits heat at a higher temperature than other circuit components is used as a high-temperature circuit component, and a high-temperature circuit component group is configured with a plurality of high-temperature circuit components, The high temperature circuit component group is separated from other circuit components, and the high temperature circuit component group is configured to cover the high temperature circuit component group so as to form a confined space between the high temperature circuit component group and the high temperature circuit component group. to form a space confined between the circuit component, together with the follow three-dimensional surface profile of the hot circuit part group, between the hot circuit part, a virtual outer connecting the outer periphery of the hot circuit part group linearly Than the line, and the high temperature circuit components enter enters the gap portion, the confining an outlet for outflow of air space, by a partition member used in the heat radiating structure for a circuit board which inlet is formed for flowing air into said containment space is there.

  According to the present invention, the confined space is formed by the partition member, and the air in the confined space is discharged to the outside while another air is flown in for ventilation. Therefore, before the heated air is released to the outside In addition, the air is not diffused.

In addition, since air having a large specific heat is passed through the confined space, the air in the confined space, which has a shape conforming to the high-temperature circuit component group and has a small volume and a small heat capacity, is relatively warm. And since the air in this confinement space is discharged | emitted rapidly, without staying, more effective heat dissipation is possible.

  In addition, since the confinement space is narrow, a small fan can be used even when the fan is attached, and the partition member can be small, so that a small and compact heat dissipation structure can be obtained.

  In addition, a small fan can be used as described above, and heat can be prevented from being diffused by partitioning a member so that hot air is not diffused, so that heat damage to circuit parts in other parts can be prevented, and its cooling structure is simple. It's okay. For this reason, energy saving can also be achieved.

The perspective view which shows a thermal radiation structure. The perspective view of the state which removed the partition member. The side view and front view of the principal part. The top view and cross-sectional view of the principal part. The longitudinal cross-sectional view of the principal part. FIG. Explanatory drawing which shows the relationship between a high temperature circuit component and a partition member. The perspective view of the metal plate used for a partition member. Sectional drawing of the metal plate used for a partition member. Sectional drawing which shows the partition member which concerns on another example. Sectional drawing which shows the partition member which concerns on another example. The perspective view which shows the thermal radiation structure which concerns on another example. The perspective view which shows the thermal radiation structure which concerns on another example. The perspective view which shows the external appearance of the partition member used for computer analysis. The perspective view which shows the result of computer analysis. The perspective view which shows the result of computer analysis. The graph which shows the temperature change which is a result of computer analysis.

An embodiment for carrying out the present invention will be described below with reference to the drawings.
FIG. 1 is an exploded perspective view showing a heat dissipation structure for releasing heat generated from the circuit components 12 and 13 mounted on the circuit board 11 to the outside. As shown in this figure, this heat dissipation structure is a structure in which some of the circuit components 12 and 13 are separated from other circuit components 13 to prevent heat diffusion and to dissipate heat. is there.

  In this example, a heat dissipation structure in which the circuit board 11 is housed in the housing 21 will be described.

  The housing 21 includes a main body 22 having a frame-like portion surrounding the circuit components 12 and 13 of the circuit board 11, and a lid body 23 attached to the upper surface of the main body 22. The main body 22 is formed with a vent 24 for ventilating the internal space and the external space. Moreover, the cover body 23 has an opening 25 penetrating in the thickness direction.

  A partition member 31 for separating a part of the circuit components 12 among the circuit components 12 and 13 is fixed to the circuit board 11. The partition member 31 has a structure in which a lower surface is opened, and covers a plurality of circuit components 12 (hereinafter referred to as “high temperature circuit components”) that generate high-temperature heat as shown in FIG. . By covering the high temperature circuit component 12 with the partition member 31, a confined space 41 (see FIG. 1) is formed between the high temperature circuit component 12 and the partition member 31.

  In the figure, reference numeral 12a denotes a heat sink as one unit with the high-temperature circuit component 12 that promotes heat dissipation of the electronic component, not the electronic component. When there is one high-temperature circuit component 12 to be classified, the partition member 31 covers only one high-temperature circuit component 12. When there are a plurality of high-temperature circuit components 12 as in the illustrated example, if possible, the circuit components 12 and 13 are arranged so that these high-temperature circuit components 12 are combined into one place or several places.

  As shown in FIGS. 3 to 6, the partition member 31 covers the high-temperature circuit component 12 closely and is made of an appropriate material. 3 (a) is a side view, FIG. 3 (b) is a front view, FIG. 4 (a) is a plan view, and FIG. 4 (b) is a partition member at the AA position in FIG. 3 (b). It is sectional drawing which shows the cross-sectional shape of 31. 5A is a cross-sectional view showing a cross-sectional shape of the partition member 31 at BB in FIG. 4A, and FIG. 5B is a partition member 31 at CC in FIG. 4A. FIG. 5C is a cross-sectional view showing the cross-sectional shape of the partition member 31 at DD in FIG. 4A, and FIG. 6 is a cross-sectional view taken along line E-E in FIG. It is sectional drawing which shows the cross-sectional shape of the partition member 31 of.

  That is, the partition member 31 includes a peripheral wall 32 that surrounds the periphery, and a top plate 33 that closes the top surface of the peripheral wall 32, and enters and exits the peripheral wall 32 and the top plate 33 according to the surface solid shape of the high-temperature circuit component 12. An uneven portion 34 is formed. If the gap is narrow even if there are a plurality of high-temperature circuit components 12 to be divided, the uneven portion 34 is not necessary at that portion.

  The concavo-convex shape portion 34 is not a shape that extends linearly irrespective of the concavo-convex shape of the surface solid shape of the high-temperature circuit component 12 but a shape that dents or swells like the concavo-convex shape. That is, the partition member 31 having the concavo-convex shape portion 34 has a shape that is completely similar to the three-dimensional shape of the surface of the high-temperature circuit component 12 and a cylindrical shape that extends linearly regardless of the concavo-convex shape of the surface three-dimensional shape of the high-temperature circuit component 12. And an intermediate shape. This is because the confined space 41 having a small volume is formed around the high-temperature circuit component 12. As a result, the shape of the confinement space 41 becomes a shape that goes in and out in accordance with the surface solid shape of the high-temperature circuit component 12.

  Since the volume of the confinement space 41 is preferably small, the shape of the partition member 31 having the uneven portion 34 is preferably close to a shape that is completely similar to the three-dimensional surface shape. This shape is fixed to the circuit board 11. It is set in consideration of air in and out as much as possible. For this reason, for example, a relatively wide space is provided around the terminal portion at the lower end of the high-temperature circuit component (see FIGS. 5A, 5C, and 6).

  Such a partition member 31 is in a form that can be densely covered from above with respect to the high-temperature circuit component group 14, and the form and arrangement of the high-temperature circuit components 12 constituting the high-temperature circuit component group 14, It is formed in an appropriate form according to the number of sets of high temperature circuit components 12. In addition, an air outlet 35 from the confining space 41 and an air inlet 36 to the confining space 41 are formed.

  The shape of the illustrated example will be described. When the peripheral wall 32 is viewed in a cross section, as shown in FIG. 4B, the portion corresponding to the linear portion in the outer periphery of the assembly of the high-temperature circuit components 12 is A linear portion 34a is formed along the portion, and a curved portion 34b along the portion is formed at a portion corresponding to the curved portion on the outer periphery of the set of high-temperature circuit components 12. In a portion corresponding to the corner portion, a protruding corner portion 34c having a substantially L shape along the portion is formed, and a gap is appropriately provided between the high temperature circuit components 12 on the outer periphery of the assembly of the high temperature circuit components 12. A entering portion 34d is formed. An alternate long and short dash line in FIG. 4B is a virtual outer peripheral line 16 that linearly connects the outer periphery of the set of high-temperature circuit components 12. The depth and shape of the entry portion 34d are appropriately set in consideration of workability based on the material of the partition member 31.

  When the peripheral wall 32 is viewed in a longitudinal section, as shown in FIGS. 5 and 6, the peripheral wall 32 is appropriately formed between the high-temperature circuit components 12, and has an uneven portion 34 as appropriate.

  The same applies to the top plate 33. As shown in FIGS. 5 and 6, the top plate 33 is formed in accordance with the shape of the high-temperature circuit component 12, and includes a straight portion 34a, a curved portion 34b, a protruding corner portion 34c, and a entering portion 34d. Have. 5 and 6, the alternate long and short dash line is a virtual outer peripheral line 16 that linearly connects the outer periphery of the set of high-temperature circuit components 12. The presence / absence, depth, and shape of the entry portion 34d are appropriately set in consideration of workability and necessity based on the material of the partition member 31. For example, in FIG. 5 (a) and FIG. 5 (c), the entry portion 34d corresponding to the portion between the high-temperature circuit components 12 is formed, but in FIG. 5 (b), the entry portion corresponding to the portion between the heat sinks 12a. 34d is not formed. Further, the entry portion 34d is not formed in a portion corresponding to the groove of the heat sink 12a. This is because air circulation is taken into consideration.

  In addition, corner rounds are formed at each part of the peripheral wall 32 and the top plate 33 and at corner portions between them in order to prevent air from staying in the confined space 41 as much as possible. The strength can be improved by forming the corner radius.

  The confinement space 41 formed by fixing the partition member 31 is thin and approximate to the three-dimensional surface shape of the high-temperature circuit component 12, and the inner surface of the partition member 31 is close to the high-temperature circuit component group 14. Moreover, the confinement space 41 is integral with no isolated portion.

  The outlet 35 is formed at one end of the top plate 33 as shown in FIG. 5B, and the outlet 35 is integrally provided with an exhaust pipe portion 35a extending upward. . The exhaust pipe part 35 a has a length connected to the opening 25 of the lid body 23. That is, the outlet 35 communicates directly with the outside.

  The inlet 36 is formed at a corner of the top plate 33 opposite to the outlet 35 as shown in FIG. The inlet 36 is formed obliquely downward and is provided with a small fan 37. The small fan 37 feeds air into the confined space 41. The confinement space 41 is small and narrow as described above. For this reason, it is possible to use a fan that is smaller than a fan used when air is discharged into a wide space. The arrangement and number of small fans 37 are set as appropriate.

  The direction, position, and number of the outlets 35 and 36 are appropriately set. The small fan 37 may be omitted.

  The partition member 31 in the illustrated example has a structure in which all portions are formed to have the same thickness, so that the inner surface and the outer surface have the same shape, but the inner surface and the outer surface are formed, for example, in the case of a synthetic resin molded product. In the case where the shapes do not need to be the same, the inner surface is formed so as to have the above shape.

  A preferred example of the relationship between the high-temperature circuit component 12 and the partition member 31 will be specifically described with reference to the schematic diagram of FIG. In FIG. 7, 12 is a CPU as a high-temperature circuit component, and 12a is a heat sink, but the same applies to other high-temperature circuit components 12 as well.

  As shown in FIG. 7A, the partition member 31 is formed in a shape like an inverted cup as a whole, and the top plate 33 is formed flat. And the said exit 35 is formed in this top plate 33, and the exhaust pipe part 35a extended upwards is provided in the exit 35. As shown in FIG.

  On the other hand, an inlet 36 is formed below the peripheral wall of the partition member 31. The position of the inlet 36 is set slightly above the height of the upper surface of the CPU (high temperature circuit component 12) that is a heat source. This is because outside air can be taken in smoothly.

  And the surrounding wall 32 of the partition member 31 which formed the inlet 36 is formed so that it may incline inside, so that an upper side may be carried out. That is, when the lower end gap A and the upper end gap B between the peripheral wall 32 and the heat sink 12a are compared, the lower end gap A is formed to be larger than the upper end gap B.

  Further, the distance H between the top plate 33 of the partition member 32 and the upper end of the heat sink 12a is made larger than the gap B at the upper end.

  When the partition member 31 and the high-temperature circuit component 12 have such a positional relationship, the heat capacity of the air in the confined space 41 is reduced, so that the heat exchange speed is increased and the speed of the air flow by convection is increased. Further, the negative pressure due to the chimney effect based on the distance H can also be used to quickly exhaust the air that has become hot. Note that the chimney effect is further enhanced when the outlet 35 is wider and the exhaust pipe portion 35a is longer.

  Further, in order to promote the discharge of air in the confined space 41, as shown in FIG. 7B, an exhaust path 38 is formed on the outlet 35, and a fan 39 for supplying air to the exhaust path 38 is formed. And a narrow portion 38a having a narrow width F smaller than the diameter E on the fan 39 side can be formed, and a negative pressure state can be created by the venturi effect.

  The material of the partition member 31 is appropriately selected as described above. For example, in the case of an ECU or the like housed in an in-vehicle electrical junction box, the size is small. From the viewpoint of workability, It is preferable to use a metal plate 51 (including a foil) as shown in FIG. The metal plate 51 has corrugated portions that make the cross-sectional shape corrugated vertically and horizontally. In addition to having the entire wavy processed part, it may have a part.

  The metal plate 51 having the corrugated processed portions in the vertical and horizontal directions has an advantage of excellent deformability and shape retention. In FIG. 8, the arrow X indicates the vertical direction, and the arrow Y indicates the horizontal direction.

  That is, the metal plate 51 is made of an aluminum thin plate, for example, and as shown in the cross-sectional view of FIG. 9A (end view taken along the line AA in FIG. 8), the metal plate 51 rises in a mountain shape when viewed from the side. It has a wavy shape having portions 52 at regular intervals, and the raised portion 52 has a first convex portion 53 having a narrow width and a first concave portion 54 having a narrower width than the first convex portion 53 in the lateral direction (FIG. 9B). On the other hand, at the lower portion between the raised portions 52, the second wide convex portion 55 and the second concave portion 56 narrower than that are repeated in the lateral direction (see FIG. 8). It is a shape of FIG.9 (c) (CC cut part end surface figure in FIG. 8).

  The first convex portion 53 has a shape in which the top surface 53a is slightly curved downward and both sides 53b are reversely U-shaped, and the first concave portion 54 has a flat bottom portion 54a. On the other hand, the second convex portion 55 has a flat top surface 55a, and the second concave portion 56 has a shape in which the bottom surface 56a is slightly curved upward and both sides 56b have a square shape. The raised portion 52, the first convex portion 53, the first concave portion 54, the second convex portion 55, and the second concave portion 56 constitute the wave-like processed portion.

  Since the metal plate 51 has such a structure, the metal plate 51 has good workability, in particular, has a high LDR (Limiting Drawing Ratio) or a limit drawing ratio, a good drawability, and can be used for complicated and fine machining.

  Moreover, since it has a corrugated processing part as mentioned above, the sound absorption / muffling function can be exhibited, and the sound emitted from a high temperature electronic component can be reduced. The metal plate 51 may have a laminated structure in which a plurality of plate materials are laminated. In this case, the vibration damping effect is enhanced, and the sound absorption / muffling effect can be improved.

  In addition, for example, in order to improve the electromagnetic wave shielding property and prevent noise disturbance, it is preferable to use an Fe—Al alloy known as having an electromagnetic wave absorbing property as a material of the metal plate 51. The partition member 31 made of Fe—Al alloy having the wave-like processed part as described above attenuates the electromagnetic wave by the irregular reflection of the electromagnetic wave by the wave-like processed part in addition to the action of the Fe—Al alloy, and obtains the electromagnetic wave shielding performance.

  The metal plate 51 made of metal is preferably thin in thickness and high in thermal conductivity. In addition, if possible, the inner surface of the partition member 31 may be increased in heat reflectivity by, for example, mirror finishing or blackened to increase the heat absorption rate. This is because the heat capacity of the partition member 31 is reduced, the temperature on the high-temperature circuit component 12 side is increased, air convection is activated, and the exhaust efficiency is increased. The property of the inner surface is set in consideration of air convection in the confined space 41.

  The partition member 31 configured as described above is fixed to the circuit board 11 by an appropriate method such as fixing of a nail (not shown) formed at the lower end of the partition member 31 in addition to fixing by a screw or rivet (not shown). Is called. In addition, for example, as shown in FIG. 10, a fixing piece 31 a fixed to the lid body 23 is provided, and the high-temperature circuit component group 14 on the circuit board 11 is covered when the lid body 23 is closed. You may do it.

  In such a heat dissipation structure of the circuit board 11, the air discharged by the small fan 37 in the partition member 31 pushes out the air in the confinement space 41 in the partition member 31, and this air is passed through the outlet 35 to the lid 23. The liquid is discharged from the opening 25. For this reason, the heat of the part covered with the partition member 31 can be prevented from diffusing to the outside of the partition member 31, and heat insulation can be achieved. In this state, the circuit component 13 and the partition member 31 that are not covered with the partition member 31 are air-cooled by the air flow entering and exiting from the vent 24 into the housing 21, so that the temperature of the target to be air-cooled is low. The effect of air cooling can be improved.

  Since the partition member 31 densely covers the outside of the high-temperature circuit component group 14 according to their shape as in the illustrated example, the confining space 41 has a small volume. For this reason, when the high-temperature electronic component group 14 covered by the partition member 31 through the small-capacity confinement space 41 generates heat, the air that has received the heat is in a state of being confined in the confinement space 41. And try to move towards the exit. This movement is urged by the small fan 37, and the heated air is discharged one after another. On the other hand, air flows from the inlet 36 by the small fan 37. That is, the air in the confined space 41 is quickly discharged outside without being diffused as soon as it is heated by the heat generated by the high-temperature circuit component 12.

  As a result, the ventilation is good, heat does not accumulate on the circuit board 11, and a constant temperature state in which the circuit components 12 and 13 are prevented from becoming high temperature is obtained. The air in the confinement space 41 is discharged from the outlet to the outside.

  Further, since the confined space 41 is narrow, the small fan 37 may be small, and the partition member 31 may be small, so that a small and compact heat dissipation structure can be obtained.

Furthermore, since heat insulation is performed and hot air is not diffused like a heat insulator, the cooling structure of other parts may be simple. For this reason, an inexpensive component having a low heat-resistant temperature can be used as the circuit component, and the cost can be reduced.
In addition, since the small small fan 37 can be used as described above, it is possible to save energy. In the case where a plurality of small fans 37 are provided, energy saving can be achieved by selectively performing ON / OFF control of the small fans, for example, by preferentially exhausting a portion having a high heat generation temperature. be able to.

Hereinafter, other embodiments will be described. In this description, parts that are the same as or equivalent to those in the previous configuration are given the same reference numerals, and descriptions thereof are omitted.
FIG. 11 shows a longitudinal section of the casing 21 having a heat dissipation structure. The partition member 31 shown in this figure is formed in a shape suitable for the expression of partitioning the high-temperature circuit component 12 rather than covering the high-temperature circuit component 12 as described above, and surrounds the high-temperature circuit component 12. That is, the fixed piece 31a fixed to the lower surface of the lid body 23 is formed above a position corresponding to the outer peripheral edge of the assembly of the high-temperature circuit components 12, and the peripheral wall portion 32 is suspended from the fixed piece 31a. The peripheral wall portion 32 is appropriately provided with a concavo-convex shape portion 34 that enters and exits according to the three-dimensional surface shape of the high-temperature electronic component 12. You may provide a top plate as needed.

  FIG. 12 is a perspective view of the heat dissipation structure, in which a set of a plurality of high-temperature circuit components 12 is divided by one partition member 31. That is, it has the several main-body part 31b corresponding to the assembly | assembly of the high temperature circuit components 12, and these main-body parts 31b are connected by the channel | path 31c which makes cross-sectional reverse U shape.

  FIG. 13 is also a perspective view of a heat dissipation structure in the case of having a set of a plurality of high-temperature circuit components 12, and in this example, a partition member 31 provided for each high-temperature circuit component 12 is connected by a duct 31d.

  In order to verify the effect of enclosing the high-temperature circuit component with the partition member 31 as described above and confining the heat generated from the high-temperature circuit component, a computer analysis using the partition material in the form shown in FIG. 14 was performed. The state of temperature change was confirmed.

  The partition member was made of an aluminum alloy, and was tightly covered with a heat sink having a configuration as shown in FIG. The exit from the internal confinement space was formed at one end of the upper surface, and the air inlet to the confinement space was formed at the bottom.

  Further, assuming a CPU at 60 ° C. as the high-temperature circuit component and a heat sink fixed on the CPU, the temperature change at one point (X = 0, Y = 0, Z = 0) in the figure was confirmed.

  FIG. 15 shows the result of analysis showing the state in the confined space, and FIG. 16 shows the result of analysis showing the external state. The temperature change at one point is as shown in FIG. In FIG. 17, the horizontal axis represents time (unit: second), and the vertical axis represents temperature (unit: ° C.). As can be seen from FIG. 17, although the temperature rises at the beginning of heat generation, convection occurs thereafter, the temperature gradually decreases, and the temperature rise can be prevented. From this, it can be said that the heat dissipation structure that traps heat and quickly discharges it has a certain effect.

The circuit component of the present invention corresponds to the circuit components 12 and 13 and the heat sink 12a of the one embodiment,
Similarly,
The corrugated portion corresponds to the raised portion 52, the first convex portion 53, the first concave portion 54, the second convex portion 55, and the second concave portion 56,
The present invention is not limited to the above-described configuration, and other forms can be adopted.

  For example, when the circuit board has a very thin shape, the partition member may have a structure in which the circuit component is surrounded only by partitioning in the housing.

  Further, depending on the environment for heat dissipation, the high temperature circuit component may not be surrounded by the partition member.

DESCRIPTION OF SYMBOLS 11 ... Circuit board 12, 13 ... Circuit component 12a ... Heat sink 21 ... Housing 31 ... Partition member 34 ... Uneven shape part 35 ... Outlet 36 ... Inlet 41 ... Confinement space 52 ... Raised part 53 ... 1st convex part 54 ... 1st Concave portion 55 ... second convex portion 56 ... second concave portion

Claims (6)

A circuit board heat dissipation structure for releasing heat generated from circuit components on the circuit board to the outside,
Among the circuit components mounted on the circuit board, a part of the circuit component that emits heat at a higher temperature than other circuit components is used as a high-temperature circuit component, and a high-temperature circuit component group is configured with a plurality of high-temperature circuit components,
Together delimit the hot circuit part group from other circuit components, so as to form a space confined between the high-temperature circuit components, the partition member is provided for covering the high-temperature circuit component group,
The the partition member, together with the follow three-dimensional surface profile of the hot circuit part group, between the hot circuit part constituting the high-temperature circuit component group, connecting the outer periphery of the hot circuit part group is covered with the partition member linearly From the virtual perimeter line, an intrusion part that enters the gap of the high-temperature circuit component,
An outlet through which air in the confined space flows out;
A circuit board heat dissipation structure in which an inlet for allowing air to flow into the confined space is formed. The partition member is
A peripheral wall surrounding the periphery of the high-temperature circuit component, and a top plate for closing the upper surface of the peripheral wall,
The peripheral wall is formed to be inclined inward toward the upper side so that the lower end gap between the peripheral wall and the high temperature circuit component is larger than the upper end gap,
Heat radiation structure of a circuit board according to the distance between the upper end of the high-temperature circuit components and the top plate, to claim 1 which is set larger than the gap of the upper end between said peripheral wall hot circuit components. The partition member is formed of a metal plate provided with a wave-shaped processed portion constituted by a raised portion, a first convex portion, a first concave portion, a second convex portion, and a second concave portion that are raised in a mountain shape when viewed from the lateral direction,
A first convex portion having a narrow width and a first concave portion having a narrower width than the first convex portion are laterally repeated. At a lower portion between the raised portions, the second wide convex portion and a narrower first width are formed. 2 is a wave shape having the above-mentioned raised portions that are shaped to repeat concave portions in the lateral direction at regular intervals;
The first convex portion has a shape in which the top surface is slightly curved downward and the both sides are inverted, and the first concave portion has a flat bottom portion,
3. The circuit board heat dissipation structure according to claim 1, wherein the second convex portion has a flat top surface, and the second concave portion has a shape in which the bottom surface is slightly curved upward and both sides are formed in a C shape. The heat dissipation structure for a circuit board according to any one of claims 1 to 3, wherein the partition member is formed of an Fe-Al alloy. The circuit board is housed in a housing,
The circuit board heat dissipation structure according to claim 1, wherein the outlet is connected to the housing. A partition member used for a heat dissipation structure of a circuit board, covering a part of the circuit parts to release heat generated from the circuit parts on the circuit board to the outside,
Among the circuit components mounted on the circuit board, a part of the circuit component that emits heat at a higher temperature than other circuit components is used as a high-temperature circuit component, and a high-temperature circuit component group is configured with a plurality of high-temperature circuit components,
The high temperature circuit component group is separated from other circuit components, and the high temperature circuit component group is covered so as to form a confined space with the high temperature circuit component,
To form a space confined between the high-temperature circuit components constituting the high-temperature circuit component group, with follow dimensional surface profile of the hot circuit part group, between the hot circuit part, the outer periphery of the hot circuit part group From the virtual peripheral line connecting linearly, the intrusion part that enters the gap of the high-temperature circuit component,
An outlet through which air in the confined space flows out;
A partition member used for a heat dissipation structure of a circuit board in which an inlet for allowing air to flow into the confined space is formed.