JP2017204588A - Circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem occurring when a high-heat-generating electronic component generating a comparatively large amount of heat and a low-heat-generating electronic component generating a comparatively small amount of heat and a heat sink are mounted on the same circuit board that heat generated by a first electronic component is transferred to the low-heat-generating electronic component through fins of the heat sink.SOLUTION: A circuit board 1 according to one embodiment includes: a high-heat-generating electronic component 3; a low-heat-generating electronic component 4 having a larger amount of heat generation than the high-heat-generating electronic component; a tabular power substrate member 2 where the high-heat-generating electronic component 3 and the low-heat-generating component 4 are arranged on one surface; and a heat sink 5 arranged on the other surface of the power substrate member 2. The heat sink 5 includes a plurality of radiation fin portions 7 which extend in a direction of one diagonal line of the one surface of the power substrate member 2. The power substrate member 2 includes a high-heat-generating electronic component arrangement portion where the high-heat-generating electronic component 3 is arranged on one corner portion out of a pair of corner portions lying on the other diagonal line of the one surface.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a circuit board, and more particularly to a circuit board having a heat sink attached thereto.

  An electronic component usually has heat resistance that can ensure an operation state against heat generated by the electronic component itself. Therefore, in general, an electronic component having a relatively large amount of heat generation (hereinafter referred to as a high heat generating electronic component) has a relatively large heat resistance and an electronic component having a relatively small amount of heat generation (hereinafter referred to as a low heat generating electronic component). ) Heat resistance is relatively small.

  When the high exothermic electronic component and the low exothermic electronic component are installed on the same circuit board, the heat generated by the high exothermic electronic component may exceed the heat resistance of the low exothermic electronic component. In order to suppress the influence of the heat generated by the highly exothermic electronic component in the low exothermic electronic component, a technique of providing a heat sink on such a circuit board is known. The heat sink is provided with a plurality of radiating fins extending from one side of a rectangular plate-like circuit board to the opposite side (for example, Patent Document 1).

JP2015-104182A (FIG. 8)

  As described above, in the circuit board provided with the conventional heat sink, the proximity heat dissipating fin exists at a position close to the highly exothermic electronic component through the circuit board. The heat generated by the highly exothermic electronic component is transferred to the adjacent heat dissipating fins. The conducted heat can be released into the atmosphere from the adjacent heat dissipating fins. Therefore, the effect which suppresses the influence in the low exothermic electronic component of the heat | fever which the high exothermic electronic component generate | occur | produced can be anticipated.

  However, since the plurality of heat radiation fins including the proximity heat radiation fins are provided so as to extend from one side of the rectangular plate-like circuit board to the opposite side, they are close to the highly heat-generating electronic component via the circuit board. Considering the situation where the heat dissipating fin that releases heat from the high heat generating electronic component and the heat dissipating fin that releases heat from the low heat generating electronic component close to the low heat generating electronic component through the circuit board are the same heat dissipating fin. It is done. In such a situation, there is a possibility that the heat of the highly exothermic electronic component that exceeds the heat resistance of the low exothermic electronic component is transmitted to the low exothermic electronic component through the same heat radiation fin. Further, in such a situation, there is a possibility that the heat radiation effect of the low heat-generating electronic component via the same heat-dissipating fin may be reduced by the heat transmitted from the high heat-generating electronic component. Dissipates heat from the heat-generating electronic components close to the high heat-generating electronic components via the circuit board and releases heat from the low-heat-generating electronic components close to the low heat-generating electronic components through the circuit board Although the correspondence which arrange | positions a low heat-emitting electronic component so that it may become a heat radiation fin different from the heat-radiating fin to perform can also be considered, it may result in restricting the freedom degree of arrangement | positioning of a low heat-generating electronic component.

  The present invention has been made in view of the above circumstances, and also in a circuit board on which a high heat generating electronic component having a relatively large heat generation amount and a low heat generating electronic component having a relatively small heat generation amount are arranged. An object of the present invention is to provide a circuit board that can suppress the influence of heat generated from a high heat-generating electronic component on the low heat-generating electronic component as much as possible while ensuring the degree of freedom of arrangement of the low heat-generating electronic component. .

  A circuit board according to the present invention includes a first electronic component, a second electronic component that generates less heat than the first electronic component, and a rectangular plate-like substrate in which the first electronic component and the second electronic component are arranged on one surface. A member and a heat dissipating member disposed on the other surface of the substrate member. The heat dissipating member includes a plurality of heat dissipating fin portions extending in the direction of a diagonal line on one surface of the substrate member.

  In the circuit board according to the present invention, the radiation fin portion is extended in the direction of the diagonal line on the one surface of the board member on which a plurality of electronic components can be arranged. In such a configuration, even when a plurality of electronic components are arranged along the width direction of the substrate member, the first heat dissipating fins are located near the first electronic component and emit heat of the first electronic component. It is possible to avoid as much as possible the situation where the portion and the second heat dissipating fin portion in the vicinity of the second electronic component that release the heat of the second electronic component become the same heat dissipating fin portion. When the first electronic component having a relatively large calorific value is arranged at one corner portion of the pair of corner portions located on the other diagonal line of one surface of the substrate member, the first heat radiation fin portion is relatively short. Therefore, even when the second electronic component having a relatively small calorific value is arranged on the board member, it is possible to avoid as much as possible the situation in which the first radiating fin portion and the second radiating fin portion are the same radiating fin portion. be able to. Therefore, it is possible to suppress as much as possible the influence of the heat generated from the high heat generating electronic component on the low heat generating electronic component while securing the degree of freedom of arrangement of the low heat generating electronic component.

It is a perspective view which shows one surface of the circuit board which concerns on Embodiment 1 of this invention. It is a simplified diagram showing the other side of the circuit board according to the first embodiment of the present invention. It is a perspective view which shows the circuit board which concerns on Embodiment 2 of this invention. It is a perspective view which shows the circuit board which concerns on Embodiment 3 of this invention. It is a perspective view which shows the circuit board based on Embodiment 4 of this invention.

  DESCRIPTION OF EMBODIMENTS Hereinafter, embodiments of a circuit board disclosed in the present application will be described in detail with reference to the accompanying drawings. The following embodiments are merely examples, and the present invention is not limited to these embodiments.

Embodiment 1 FIG.
FIG. 1 is a perspective view showing one surface of a circuit board 1 according to Embodiment 1 of the present invention. FIG. 2 is a simplified diagram showing the other surface of the circuit board 1 according to Embodiment 1 of the present invention. The circuit board 1 shown in FIG. 2 is viewed from the same direction as the circuit board 1 shown in FIG. 1 (the direction from the front side to the back side of the paper). The state where the component 3, the two low heat generating electronic components 4 and the base plate member 6 are removed is simply shown.

  The circuit board 1 includes a power board member 2, a high heat generating electronic component 3, two low heat generating electronic components 4, and a heat sink 5. A high heat generating electronic component 3 and a low heat generating electronic component 4 are arranged on one surface of the power board member 2, and a heat sink 5 is arranged on the other surface of the power board member 2 which is the back surface of the one surface. is there. In other words, the power board member 2 is provided with a high heat generating electronic component placement portion on which the high heat generating electronic component 3 is placed and a low heat generating electronic component placement portion on which the low heat generating electronic components 4 are placed on one side, 5 is provided on the other surface.

  The power board member 2 is a rectangular plate-like electric circuit board that realizes a predetermined function through the flow of current, and can amplify a three-phase AC signal generated by an inverter to give power to components such as a compressor. it can. The high heat-generating electronic component placement portion of the power board member 2 can be in a state in which a current is passed through the placed high heat-generating electronic component 3 and the function of the high heat-generating electronic component 3 is exhibited. The low heat-generating electronic component placement portion of the power board member 2 may be in a state in which a current is passed through the placed low heat-generating electronic component 4 and the function of the high heat-generating electronic component 3 is exhibited. The heat sink arrangement portion of the power board member 2 can be thermally connected to the arranged heat sink 5 to achieve a function of the heat sink 5. The power board member 2 has a function as a power converter such as a converter, an inverter, and a charger, but may be configured to have other functions.

  The power board member 2 includes a high heat generating electronic component 3 and a low heat generating electronic component 4 on one surface. The power board member 2, which is a plate-like substrate, has four corner portions that are four corners, and is high in one corner portion of the pair of corner portions located on one diagonal line of the power board member 2. A heat-generating electronic component 3 is arranged. That is, the power board member 2 includes a highly exothermic electronic component placement portion at one corner portion of a pair of corner portions located on one diagonal line on one surface. In the example shown in FIG. 1, among the pair of corner portions located on one diagonal line extending from the upper left to the lower right of the page, the upper left corner corresponds to the high heat generating electronic component placement portion, and the high heat generation The highly exothermic electronic component 3 is arranged at the electronic component arrangement site. In the circuit board 1 according to the first embodiment, the power board member 2 functions as an example of the board member according to the present invention.

  The power board member 2 shown in FIG. 1 is formed in a rectangular shape. However, the power board member 2 may have a trapezoidal shape, a parallelogram shape, a rhombus shape, or the like. Further, the four corners of the power board member 2 shown in FIG. However, the corners of the power board member 2 may be rounded by chamfering or the like. Specifically, the shape may be such that those skilled in the art can substantially recognize it as a corner portion.

  The highly exothermic electronic component 3 is a component that generates a relatively large amount of heat, and is, for example, a magnetic component such as a reactor or a transformer. The low heat generating electronic component 4 is a component that generates a smaller amount of heat than the high heat generating electronic component 3, and is an element that may deteriorate at a high temperature, such as a capacitor. In order to suppress deterioration due to its own heat generation, in general, an electronic component having a larger amount of heat generation has higher heat resistance. That is, the high heat generating electronic component 3 has higher heat resistance than the low heat generating electronic component 4. On the contrary, the low heat generating electronic component 4 has lower heat resistance than the high heat generating electronic component 3.

  The heat sink 5 is an example of a heat dissipating member that emits heat generated by the electronic components on the power board member 2, and is made of, for example, aluminum. The heat sink 5 is provided with a base plate member 6 that is in thermal contact with the high exothermic electronic component 3 and the low exothermic electronic component 4 via the power substrate member 2 on one side, and the high exothermic electronic component 3 and the low exothermic electronic component. Seven radiating fin portions 7 for releasing heat transmitted from the component 4 to the base plate member 6 into the atmosphere are provided on the other surface.

  The base plate member 6 is a plate-like portion corresponding to the power board member 2, and the power board member 2 provided with the high heat generating electronic component 3 and the low heat generating electronic component 4 is arranged on one surface, The radiation fin part 7 is arrange | positioned on the other surface.

  Each radiating fin portion 7 is a plate-like protrusion portion designed to widen the heat transfer area for improving heat exchange efficiency, and is on one diagonal line of the power board member 2 where the highly heat-generating electronic component 3 is located. Is extended to the other surface of the base plate member 6 in the opposite diagonal direction. Further, each radiating fin portion 7 is separated from other radiating fin portions 7 with respect to the direction of one diagonal line of the power board member 2. In the example shown in FIG. 2, each radiating fin portion 7 extends so as to correspond to the other diagonal line opposite to the one diagonal line of the power board member 2 and to extend from the lower left to the upper right of the paper surface.

  In the example of the heat radiating fin portion 7 shown in FIGS. 1 and 2, the power board member 2 extends on the other surface of the base plate member 6 in the direction of another diagonal line opposite to the one diagonal line. However, the radiating fin portion 7 may be extended so as to be inclined with respect to one side of one surface of the power board member 2 by adding an angle to the direction of other diagonal lines. In other words, the circuit board according to the present invention is not limited to a configuration in which the radiating fin portions 7 are arranged so as to extend in parallel strictly along other diagonal lines. In other words, even if there is a slight angle with respect to the direction of the other diagonal line, the heat radiation fin part 7 only needs to extend substantially in the direction of the other diagonal line.

  In the heat sink 5 illustrated in FIG. 2, the number of fins for heat radiation is seven. However, as long as the heat transmitted to the base plate member 6 can be efficiently released, the heat sink 5 may be configured to include the other number of radiating fin portions 7.

  Among the seven radiating fin portions 7, a gap passage is formed between two adjacent radiating fin portions 7. In the example shown in FIG. 2, a clearance passage extending from the lower left side to the upper right side of the paper surface is formed for each radiating fin portion 7 extending from the lower left side to the upper right side of the paper surface. When air passes through the gap passage, the heat dissipation effect through the heat sink 5 is improved. In order to further improve the heat dissipation effect via the heat sink 5, there is a plate width direction between the heat radiation fin portions 7 in the base plate member 6, that is, between the heat radiation fin portions 7 and the heat radiation fin portions 7. There are gap holes (not shown) opened in the plate thickness direction (z direction in FIGS. 1 and 2) perpendicular to the plate height direction (y direction in FIGS. 1 and 2) and the plate height direction (y direction in FIGS. 1 and 2). It is formed. The power board 2 also has air holes (not shown) corresponding to the gap holes. Therefore, air can also flow in the plate thickness direction (z direction in FIGS. 1 and 2).

  As a cooling method for cooling the heat sink 5, either natural air cooling or forced air cooling may be used. In the case of natural air cooling, there is no need to add special components. When air is naturally cooled and air flows in the plate length direction of the base plate member 6 (y direction in FIGS. 1 and 2), the width direction of the base plate member 6 of the base plate member 6 (x in FIGS. 1 and 2). The inclination angle of the radiating fin portion 7 with respect to (direction) is preferably 45 degrees or more. This is because the flow rate of air between the radiating fin portions 7 is increased, and the heat dissipation effect is enhanced. In the case of forced air cooling, a cooling fan may be prepared, and the heat sink 5 may be cooled by wind generated by rotating the prepared cooling fan.

  In the circuit board 1 illustrated in FIG. 1, the power board member 2 is held so that the long side (length) is vertical (up and down). The air warmed by the radiation fin portions 7 of the circuit board 1 illustrated in FIG. 1 is lightened and moves vertically upward. Therefore, in the circuit board 1 illustrated in FIG. 1, it is possible to avoid a situation where the low heat generating electronic component 4 is warmed by the heat released from the heat radiating fin portion 7.

  When the low heat generating electronic component 4 is disposed in the vicinity of the high heat generating electronic component 3, the heat generated by the high heat generating electronic component 3 is transmitted to the surface direction of the base plate member 6 and affects the low heat generating electronic component 4. In order to avoid this, the heat sink 5 having the heat radiating fin portions 7 is installed. However, in the conventional circuit board in which the radiating fin portion 7 extends so as to extend in the plate width direction (x-axis direction in FIGS. 1 and 2) or the plate height direction (y-axis direction in FIGS. 1 and 2). When the low heat-generating electronic component 4 is disposed so as to be provided with the high heat-generating electronic component 3 disposed at an arbitrary position, the high heat-generating electronic component 3 and the low heat-generating electronic component 4 form the base plate member 6. There may also be a situation in which they are arranged on the same radiating fin portion 7. In such a situation, the heat generated by the highly exothermic electronic component 3 may be transferred to the low exothermic electronic component 4 through the same radiating fin portion 7 and the temperature of the low exothermic electronic component 4 may be increased. There is. Further, the heat generated by the high heat-generating electronic component 3 may reduce the heat radiation effect for the heat generated by the low-heat-generating electronic component 4. Further, when the low heat-generating electronic component 4 is disposed on the heat radiating fin portion 7 different from the disposed high heat-generating electronic component 3 via the base plate member 6, the low heat-generating electronic component 4 can be freely arranged. There is also a possibility that the degree is limited.

  In the circuit board 1 according to the first embodiment, as shown in FIGS. 1 and 2, one corner portion of the pair of corner portions located on one diagonal line of the power board member 2 is replaced with a highly heat-generating electronic component placement portion. The high exothermic electronic component 3 having a large calorific value is arranged in the high exothermic electronic component arrangement part, and the base plate member 6 is arranged with the plurality of heat dissipating fin parts 7 in the diagonal direction of the power board member 2 of the power board member 2. It extends on the other side. With this configuration, the heat dissipating fin portion 7 for releasing the heat of the highly exothermic electronic component 3 can be provided at a position close to the highly exothermic electronic component 3 via the power board member 2 and the base plate member 6. The dimensions of the radiating fin portion 7 in the plate width direction (x-axis direction in FIGS. 1 and 2) and the plate height direction (y-axis direction in FIGS. 1 and 2) can be made as short as possible. Therefore, even when the low heat generating electronic component 4 is disposed in the vicinity of the high heat generating electronic component 3, heat dissipation provided at a position close to the high heat generating electronic component 3 via the power board member 2 and the base plate member 6. It is easy to avoid the situation where the fin portion 7 and the heat dissipating fin portion 7 provided in the vicinity of the low heat-generating electronic component 4 through the power board member 2 and the base plate member 6 become the same heat dissipating fin portion 7. Become.

  When the size of the highly exothermic electronic component 3 approaches the size of the power board member 2, the highly exothermic electronic component 3 is arranged so as to close one corner portion of the power board member 2, and is on the same diagonal line as the one corner portion. The highly exothermic electronic component 3 is arranged so as not to cover the vicinity of the other corner portion. With such a configuration, the highly exothermic electronic component 3 is substantially disposed at one corner of the power board member 2.

  Here, the corner part of the power board member 2 means an area that is not the central part of the power board member 2, and means an area within a predetermined distance from the four corners. The distance from the four corners is preferably a half of the short side of the power board member 2, and the closer to the long side of the highly heat-generating electronic component 3, the better.

  In the circuit board 1 illustrated in FIG. 1, the highly exothermic electronic component 3 is disposed at the upper left corner of the power board member 2, but another highly exothermic electronic component is disposed at the other three corners. Not placed. However, other highly exothermic electronic components may be arranged at the other three corners. When another high voltage electronic component is arranged at another corner portion on the same diagonal as the corner portion where the high heat generating electronic component 3 is arranged, the high heat generating electronic component 3 and another high heat generating electronic component are different from each other. The heat dissipating fin part 7 of the high heat generating electronic component 3 and the heat dissipating fin part 7 of another high heat generating electronic component are shorter than the other heat dissipating fin parts 7 and have low heat generation. This is because the degree of freedom of arrangement of the electronic component 4 can be secured. Further, when another high-voltage electronic component having the same heat resistance is disposed at another corner portion that is not on the same diagonal as the corner portion where the high heat-generating electronic component 3 is disposed, a heat radiation fin that radiates heat to the high-voltage electronic component 3 A configuration in which the low heat generating electronic component 4 is not disposed on the heat radiating fin portion that radiates heat to the portion 7 and another high voltage electronic component is preferable.

  In the circuit board 1 illustrated in FIG. 1 and FIG. 2, the heat dissipating fin portion 7 that radiates heat of the high-voltage electronic component 3 is short, but the heat dissipating fin portion 7 that dissipates heat of the low heat-generating electronic component 4 is long. it can. Therefore, it is possible to maintain the heat radiation effect for the low heat-generating electronic component 4 with low heat resistance higher than the heat radiation effect for the high-voltage electronic component 3 with high heat resistance, while ensuring the degree of freedom of arrangement of the low heat-generating electronic component 4. It becomes possible.

  When air flows through a gap passage formed between the plurality of heat radiation fin portions 7, each heat radiation fin portion 7 is cooled. In the circuit board 1 according to the first embodiment, the heat dissipating fin portion that releases the heat of the high heat generating electronic component 3 is different from the heat dissipating fin portion that releases the heat of the low heat generating electronic component 4. Therefore, it is possible to suppress the air that has been heated by cooling the heat dissipating fin part that releases the heat of the high heat-generating electronic component 3 from coming into contact with the heat dissipating fin part that discharges the heat of the low heat-generating electronic component 4. Therefore, even when the low heat-generating electronic component 4 is arranged in the vicinity of the high heat-generating electronic component 3, the heat-radiating fin portion that releases the heat of the high heat-generating electronic component 3 is cooled and reduced depending on the heated air. The situation where the cooling effect with respect to the exothermic electronic component 4 falls can be avoided as much as possible.

  In the circuit board 1 according to the first embodiment, the highly exothermic electronic component 3 is disposed in at least one of a pair of corner portions on one diagonal line on the power board member 2, and the heat dissipating fin portion 7. Is extended so as to extend in the other diagonal direction of the power board member 2. Therefore, most of the positions on the power board member 2 do not exist on the radiation fin portions 7 that radiate the heat of the highly exothermic electronic component 3. Therefore, as compared with the conventional circuit board in which a plurality of radiating fin portions are extended so as to extend in the plate width direction or the plate length direction, the power board member 2 is maintained while maintaining the cooling effect on the low heat-generating electronic component 4. A sufficient degree of freedom in arranging the low heat-generating electronic component 4 can be secured above.

  In the first embodiment, a circuit board 1 having seven radiating fin portions 7 is illustrated. However, the number of radiating fin portions 7 may be other than seven.

  In the first embodiment, a circuit board 1 having one highly heat-generating electronic component 3 is illustrated. However, the number of high heat-generating electronic components 3 may be two or more. When the second highly exothermic electronic component 3 is disposed, the other corner portion of the pair of corner portions located on one diagonal line of the power board member 2 (other than the other one paired with the aforementioned one corner portion) The high heat-generating electronic component placement portion for the second high-heat generation electronic component 3 is used at the corner portion), and the second high heat-generation electronic component 3 may be placed in the high heat-generation electronic component placement portion.

  In the first embodiment, a circuit board 1 having two low heat generating electronic components 4 is illustrated. However, the number of low heat generating electronic components 4 may be other than two. In the circuit board 1 according to the first embodiment, since most of the positions on the power board member 2 do not exist on the radiating fin portion 7 that radiates the heat of the highly exothermic electronic component 3, three or more low exothermic electronic components are provided. 4, that is, in the case where three or more low heat-generating electronic component placement portions are provided, the power board member 2 and the base plate member 6 are disposed at positions close to the high heat-generating electronic component 3. A situation in which the radiating fin portion 7 and the radiating fin portion 7 provided at positions facing the three or more low heat-generating electronic components 4 via the power board member 2 and the base plate member 6 become the same radiating fin portion 7. It becomes easy to avoid. In other words, one of the plurality of electronic components included in the circuit board 1 is selected as a highly exothermic electronic component having the largest amount of heat generation, and one corner portion of the pair of corner portions located on one diagonal line of the power board member 2. By arranging the highly heat-generating electronic components selected in the above, it is possible to suppress the influence of the heat generated by the selected high-heat-generating electronic components on other electronic components while ensuring the degree of freedom of placement of other electronic components. it can.

  In the first embodiment, a plurality of heat radiation fin portions 7 are located on the base plate member 6. However, the base plate member 6 is removed, and a plurality of heat dissipating fin portions 7 are directly arranged on the other surface opposite to one surface of the power board member 2 on which the high heat generating electronic component 3 and the low heat generating electronic component 4 are disposed. It is good. In the case of this configuration, since the preparation of the base plate member 6 is not necessary, a cost reduction effect can be expected.

  In the first embodiment, a highly exothermic electronic component placement site is provided at one corner of a pair of corners located on one diagonal line of one surface of the power board member 2, and the highly exothermic electronic component placement site A highly exothermic electronic component 3 is arranged. However, the high heat-generating electronic component 3 may be configured to be disposed on the plate-like plane portion of the power board member 2 within a range that does not become near the heat-dissipating fin portion 7 that performs heat dissipation of the low-heat-generating electronic component 4.

Embodiment 2. FIG.
FIG. 3 is a perspective view showing a circuit board 1 according to Embodiment 2 of the present invention. In the example of FIG. 3, a recessed portion 8 is provided in the portion of the power board member 2 where the highly heat-generating electronic component 3 is disposed. Regarding the circuit board 1 according to the second embodiment, the description of the same configuration as that of the circuit board 1 according to the first embodiment is omitted.

  In the circuit board 1 according to the first embodiment, as shown in FIG. 1, a high exothermic electronic component 3 and a low exothermic electronic component 4 are provided on a flat plate-like power board member 2. That is, in the circuit board 1 according to the first embodiment, the high heat generating electronic component 3 and the low heat generating electronic component 4 are mounted on the same plane. However, in the circuit board 1 according to the second embodiment, as shown in FIG. 3, each of the pair of corner portions located on one diagonal line of the base plate member 6 is provided with the recess portions 8. A highly exothermic electronic component 3 is arranged. That is, the recessed part 8 which becomes a concave shape toward the heat sink 5 side is arrange | positioned in the highly exothermic electronic component arrangement | positioning part of the base board member 6. FIG. The low heat-generating electronic component 4 is disposed on the power board member 2 at a portion other than the recessed portion 8. That is, a portion other than the recessed portion 8 on the power board member 2 is a low heat generating electronic component placement portion. The highly exothermic electronic component 3 and the low exothermic electronic component 4 arranged on the base plate member 6 are electrically connected to the power board member 2. In the circuit board 1 according to the second embodiment, the combination of the power board member 2 and the base plate member 6 functions as an example of the board member according to the present invention.

  The recessed portion 8 is configured such that the power board member 2 is recessed in the thickness direction (z direction in FIG. 3). That is, in the circuit board 1 according to the second embodiment, the mounting position of the high heat generating electronic component 3 in the plate thickness direction (z direction in FIG. 3) and the low heat generating electronic component 4 in the plate thickness direction (z direction in FIG. 3). The mounting position is different. In other words, in the circuit board 1 according to the second embodiment, the low heat-generating electronic component 4 is mounted on the front side of the paper (the negative direction in the z direction in the figure) of the high heat-generating electronic component 3 so that the high heat-generating electronic The component arrangement position is configured to be located closer to the heat sink 5 than the low heat-generating electronic component position.

  In the circuit board 1 according to the second embodiment, the mounting position of the high heat generating electronic component 3 and the mounting position of the low heat generating electronic component 4 are different in the plate thickness direction (z direction in FIG. 3). Therefore, even if the high heat-generating electronic component 3 is a tall component such as a magnetic component such as a reactor and a transformer, the overall height of the circuit board 1 can be reduced. Therefore, it is possible to reduce the size of the circuit board 1 while maintaining the cooling effect on the low heat-generating electronic component 4 and ensuring the degree of freedom for arranging the low heat-generating electronic component 4.

  By providing the recessed portion 8 in a part of the power board member 2, the heat transfer path from the high heat generating electronic component 3 to the low heat generating electronic component 4 becomes long. Therefore, the thermal resistance from the high heat generating electronic component 3 to the low heat generating electronic component 4 is increased. Therefore, the amount of heat transferred from the high heat generating electronic component 3 to the low heat generating electronic component 4 is reduced, and the temperature rise of the low heat generating electronic component 4 can be reduced. Here, the thermal resistance means a temperature difference necessary for releasing 1 W of heat from a certain object. If this value is high, it is difficult to transmit the temperature, and if this value is low, it means that the temperature is easily transmitted. Value.

  In the example of FIG. 3, the highly heat-generating electronic component 3 is disposed by providing the recessed portions 8 at two locations on the power board member 2. However, the structure which provides the hollow part 8 only in either one may be sufficient. Moreover, the hollow part 8 is provided only in one place, and one of the two high heat-generating electronic components 3 is disposed in the hollow part 8, and the other one radiates heat from the low heat-generating electronic component 4. You may arrange | position in the plate-shaped plane part of the power board | substrate member 2 in the range which does not become the vicinity of the radiation fin part 7. FIG.

  The power board member 2 of the circuit board 1 according to the second embodiment is provided with a recessed portion 8. A base plate member 6 is disposed on one surface of the power board member 2 (one surface on the positive direction side in the z direction in FIG. 3). The base plate member 6 may be provided with a recessed portion according to the shape of the recessed portion 8. When the recessed part is provided also in the base board member 6, you may shorten the thickness (length of the positive direction of the z direction of FIG. 3) of the recessed part position with respect to the radiation fin part 7. FIG. This is because the overall size of the circuit board 1 can be made as small as possible despite the provision of the recessed portion.

Embodiment 3 FIG.
FIG. 4 is a perspective view showing a circuit board 1 according to Embodiment 3 of the present invention. In the example of FIG. 4, the step board portion 9 is provided in the portion of the power board member 2 on which the high heat generating electronic component 3 is arranged. Regarding the circuit board 1 according to the second embodiment, the description of the same configuration as that of the circuit board 1 according to the first embodiment is omitted.

  In the circuit board 1 according to the first embodiment, as shown in FIG. 1, a high exothermic electronic component 3 and a low exothermic electronic component 4 are provided on a flat plate-like power board member 2. That is, in the circuit board 1 according to the first embodiment, the high heat generating electronic component 3 and the low heat generating electronic component 4 are mounted on the same plane. However, in the circuit board 1 according to the third embodiment, as shown in FIG. 4, stepped substrate parts 9 are provided in each of a pair of corner parts located on one diagonal line of the plate-like power board member 2, The highly exothermic electronic component 3 is disposed on the stepped substrate portion 9. The low heat generating electronic component 4 is configured such that the power board member 2 has a step in the thickness direction (z direction in FIG. 3). That is, in the circuit board 1 according to the third embodiment, the mounting position of the high heat generating electronic component 3 in the plate thickness direction (z direction in FIG. 3) and the low heat generating electronic component 4 in the plate thickness direction (z direction in FIG. 3). The mounting position is different. In other words, in the circuit board 1 according to the third embodiment, a step substrate portion that generates a step toward the heat sink 5 is provided, and the high heat generating electronic component placement portion is located at the step substrate portion, and the high heat generating electronic component A low heat-generating electronic component 4 is mounted on the front side of the paper (a negative direction in the z direction in the figure) with respect to FIG. That is, the high heat generating electronic component placement site is located closer to the heat sink 5 than the low heat generating electronic component placement site.

  In the circuit board 1 according to the third embodiment, the mounting position of the high heat generating electronic component 3 and the mounting position of the low heat generating electronic component 4 are different in the thickness direction (z direction in FIG. 4). Therefore, even if the high heat-generating electronic component 3 is a tall component such as a magnetic component such as a reactor and a transformer, the overall height of the circuit board 1 can be reduced. Therefore, it is possible to reduce the size of the circuit board 1 while maintaining the cooling effect on the low heat-generating electronic component 4 and ensuring the degree of freedom for arranging the low heat-generating electronic component 4.

  By providing the step board portion 9 in a part of the power board member 2, the heat transfer path from the high heat generating electronic component 3 to the low heat generating electronic component 4 becomes long. Therefore, the thermal resistance from the high heat generating electronic component 3 to the low heat generating electronic component 4 is increased. Therefore, the amount of heat transferred from the high heat generating electronic component 3 to the low heat generating electronic component 4 is reduced, and the temperature rise of the low heat generating electronic component 4 can be reduced.

  In the example of FIG. 4, the stepped board portions 9 are provided at two places on the power board member 2, and the highly exothermic electronic components 3 are arranged. However, the stepped substrate portion 9 may be provided on only one of them. Further, the step board portion 9 is provided only in one place, one of the two highly heat-generating electronic components 3 is arranged on the step board portion 9 and the other one is a plate-like plane of the power board member 2. You may arrange in a part.

  A step board portion 9 is provided on the power board member 2 of the circuit board 1 according to the third embodiment. A base plate member 6 is disposed on one surface of the power board member 2 (one surface on the positive direction side in the z direction in FIG. 4). Depending on the shape of the stepped substrate portion 9, the base plate member 6 may be provided with a stepped substrate portion portion that causes a step. When the base plate member 6 is also provided with the stepped substrate portion, the thickness of the portion located in the stepped substrate portion (the length in the positive direction in the z direction in FIG. 4) is shortened with respect to the radiation fin portion 7. May be. This is because the overall size of the circuit board 1 can be made as small as possible despite the provision of a step board portion that generates a step.

Embodiment 4 FIG.
FIG. 5 is a perspective view showing a circuit board 1 according to Embodiment 4 of the present invention. FIG. 5 shows an example of the circuit board 1 as viewed from the heat sink 5 side rather than from the power board member 2 side. Regarding the circuit board 1 according to the fourth embodiment, the description of the same configuration as the circuit board 1 according to the first embodiment is omitted.

  In the circuit board 1 according to the first embodiment, as shown in FIG. 2, each radiating fin portion 7 which is one plate-like member is opposite to one diagonal line of the base plate member 6 of the heat sink 5. It extends so as to extend in another diagonal direction. However, the circuit board 1 according to the fourth embodiment extends so as to extend in the direction of one diagonal line rather than on another diagonal line. Further, as shown in FIG. 5, the radiating fin fragments 10 that are shortened by cutting each radiating fin portion extending so as to extend in one diagonal direction of the base plate member 6 at a midpoint in the extending direction. It is comprised so that two or more may be provided. Although the illustration of the high heat generating electronic component 3 is omitted, the high heat generating electronic component 3 is arranged at a high heat generating electronic component arrangement portion located at one corner portion of a pair of corner portions located on another diagonal line. Although not shown, the low heat-generating electronic component 4 is disposed at a low heat-generating electronic component arrangement site corresponding to a position on the power board member 2 other than the corner portion where the high heat-generating electronic component 3 is disposed. It is.

  The plurality of radiating fin segments 10 are linearly arranged side by side in the direction of one diagonal line while being separated from each other. By adopting a configuration including such a plurality of heat radiation fin segments 10, the temperature boundary layer on each heat radiation fin portion 7 of the heat sink 5 of the first embodiment can be reset in the extending direction. Moreover, by setting it as the structure provided with such a some radiation fin piece 10, a new air will flow in from the clearance gap part of the adjacent radiation fin piece 10 and the radiation fin piece 10. FIG. Therefore, it is possible to further suppress the temperature rise of the air due to the heat taken from the high heat generating electronic component 3 and the low heat generating electronic component 4. Therefore, in the circuit board 1 in the fifth embodiment, the cooling performance of the entire heat sink 5 can be further improved. Here, the temperature boundary layer refers to a region where the fluid that is in contact with the wall surface and has a temperature equal to the wall surface temperature reaches a uniform fluid temperature.

  In the example of FIG. 5, the radiating fin fragment rows made up of a plurality of radiating fin fragments 10 are arranged on the plate-like base plate member 6 in six rows. However, as long as heat can be efficiently radiated, six or more rows of radiating fin fragments may be arranged, or six or fewer rows of radiating fin fragments may be arranged. Moreover, although it is set as the structure extended so that the inclination angle of each radiation fin piece 10 with respect to the board width direction of the base board member 6 may be about 45 degree | times, if it can thermally radiate efficiently, the inclination angle of each radiation fin piece 10 is set to 135. It is good also as a structure set as a degree, and it is good also as a structure set as another angle.

  The invention is not limited to the specific details and exemplary embodiments described and described above. Variations and effects that can be easily derived by those skilled in the art are also included in the invention. For example, a modified example in which the first to fourth embodiments are combined is also included in the invention. Accordingly, various modifications can be made without departing from the spirit or scope of the general inventive concept as defined by the claims and their equivalents.

1 Circuit board, 2 Power board member, 3 High heat generation electronic component, 4 Low heat generation electronic component,
5 heat sink, 6 base plate member, 7 radiating fin part, 8 recessed part, 9 stepped substrate part, 10 radiating fin fragment

Claims (9)

A first electronic component; a second electronic component that generates less heat than the first electronic component; a rectangular plate-like substrate member that disposes the first electronic component and the second electronic component on one surface; and the substrate In a circuit board having a heat dissipation member disposed on the other surface of the member,
The circuit board, wherein the heat dissipating member includes a plurality of heat dissipating fin portions extending in a direction of a diagonal line on the one surface. The circuit board according to claim 1, wherein a gap passage is formed between adjacent ones of the plurality of radiation fin portions. The circuit board according to claim 2, wherein the gap passage extends in the direction of the diagonal line. A plurality of other electronic components;
3. The circuit board according to claim 2, wherein among the plurality of other electronic components, the first electronic component, and the second electronic component, the first electronic component generates the largest amount of heat. The said board | substrate member is equipped with the 1st electronic component arrangement | positioning site | part which arrange | positions the said 1st electronic component in one corner | angular site | part of a pair of corner | angular parts located on the other diagonal of the said one surface. 5. The circuit board according to any one of 4 to 4. The board member includes a second electronic component placement site on the surface for placing the second electronic component,
The circuit board according to any one of claims 1 to 5, wherein the first electronic component placement site is located closer to the heat dissipation member than the second electronic component placement site. The substrate member includes a recessed portion having a concave shape on the heat radiating member side,
The circuit board according to claim 6, wherein the first electronic component placement site is located in the recess. The substrate member includes a step substrate portion that generates a step toward the heat radiating member,
The circuit board according to claim 6, wherein the first electronic component placement part is located in the stepped board part. 9. The heat radiating fin portion includes a plurality of heat radiating fin pieces arranged in a straight line along the direction of the diagonal line while being separated from each other. Circuit board.

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