JP2005294703A - Control unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control unit of simple radiating structure capable of better radiating heat to an electronic part of either high or low calorific value if the calorific values of a plurality of electronic components on a circuit board are different from each other. <P>SOLUTION: The control unit comprises an insulative case 10 where at least two accommodating spaces are compared; one circuit board 25 on which a first electronic component 27 that is accommodated in a first accommodating space 31 of the case and is of relatively big calorific value, and second electronic components 28, 29 that are accommodated in a second accommodating space 32 and are of relatively small calorific value, are mounted; a first resin 36 of relatively big radiating property which is filled in the first accommodating space and covers the first electronic component; and a second resin 37 of relatively small radiating property which is filled in the second accommodating space and covers the second electronic components. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a control unit in which a circuit board is accommodated in a case, and a resin is filled around an electronic component mounted on the circuit board.

  A control unit for controlling an electric device is configured by housing a circuit board on which electronic components are mounted in an insulating case. If an electric current is passed through the electronic component in order to operate the electric device, the electronic component generates heat, and if the state of a predetermined temperature or higher continues for a predetermined time or longer, the electronic component may malfunction or break down. Therefore, heat is dissipated by various heat dissipating means in order to suppress the temperature rise of the electronic component.

  For example, the amount of heat generated may be different between one of the two groups of electronic components and the other, and in this case, the heat dissipating means must be devised. In the conventional vehicle electronic device shown in FIG. 4, a circuit board 102 is supported and accommodated in an insulating case (housing) 100, and a first electronic component 104 and a second electronic component 106 are mounted on the upper surface thereof.

Here, the heat generation amount of the first electronic component 104 is larger than that of the second electronic component 106. Accordingly, the first heat radiating plate 110 attached to the first electronic component 104 has a larger surface area than the second heat radiating plate 112 attached to the second electronic component 106, and part of the first heat radiating plate 110 contacts the case 100. ing. A resin portion 116 is formed around the first electronic component 104 and the second electronic component 106.
JP 11-220264 A

  In the above-described conventional electronic device, the first heat radiating plate 110, the second heat radiating portion 112, and the resin portion 116 are provided as heat radiating means, and the number of parts is large and the structure is complicated. In addition, it is not easy to select a surface area and a shape for making the heat dissipation property of the first heat dissipation plate 110 larger than that of the second heat dissipation plate 112.

  The present invention has been made in view of the above circumstances, and when a plurality of electronic components on a circuit board have different calorific values, the number of components and the simple structure are good for both high and low calorific electronic components. An object is to provide a control unit that can dissipate heat.

The inventor of the present application has come up with the idea that the heat dissipating means is only the resin part and the heat dissipating property of the resin part is selected according to the amount of heat generated by the electronic component.
(1) The control unit according to the first invention of the present application is, as described in claim 1, an insulating case that divides at least two accommodation spaces, and is accommodated in the first accommodation space of the case. One circuit board on which the first electronic component having a large amount of heat generation and the second electronic component housed in the second space and having a relatively small amount of heat generation are mounted, and the first electronic component is filled in the first housing space and covers the first electronic component. The first resin portion having a relatively large heat dissipation property and the second resin portion having a relatively small heat dissipation property filling the second housing space and covering the second electronic component.

  In this control unit, the heat generation of the first electronic component that generates a large amount of heat is radiated by the large first resin part that radiates heat, and the heat generation of the second electronic component that generates a small amount of heat radiates the heat. Heat is dissipated in the second resin portion having a small property.

  In the heat dissipation structure of the electronic control device disclosed in Japanese Patent Laid-Open No. 11-307968, particularly in the embodiment disclosed in FIG. 4, the heat dissipation plate of the heat sink integrated storage case is used as a partition. The storage space is divided into a plurality of small spaces by partitioning, and the resin is filled in the small space for storing the electronic components that generate a large amount of heat among the plurality of small spaces, but in the small space for storing the electronic components that generate a small amount of heat. Do not fill with resin. This is different from the present invention in which all small spaces are filled with resin.

A control unit according to a second aspect is the control unit according to the first aspect, wherein the first resin portion is made of a soft resin and a filler, and the second resin portion is made of a soft resin. A control unit according to a third aspect is the control unit according to the second aspect, wherein the volume of the first resin portion is smaller than the volume of the second resin portion.
(2) The control unit according to the second aspect of the present invention is, as described in claim 4, an insulating case provided with at least two storage spaces partitioned by a partition, and a first storage space of the case. A first circuit board on which a first electronic component with a large amount of heat generation is mounted, a first resin portion that fills the first accommodation space and covers the first electronic component, and a second housing for the case A second circuit board on which a second heating element that is housed in a space and has a relatively small amount of heat generation is mounted; a second resin portion that fills the second housing space and covers the second electronic component; Consists of.

  In this control unit, the heat generation of the first electronic component that generates a large amount of heat on the first circuit board is radiated by the first resin part that covers the first heat-generating element, and the heat generation amount on the second circuit board is small. The heat generated by the two electronic components is radiated by the second resin part covering the same and having a small heat dissipation property.

  A control unit according to a fifth aspect is the control unit according to the fourth aspect, wherein the first resin portion is made of a soft resin and a filler, and the second resin portion is made of a soft resin. A control unit according to a sixth aspect is the control unit according to the fifth aspect, wherein the volume of the first resin portion is smaller than the volume of the second resin portion.

  According to the control unit according to the first aspect of the invention, the heat generation of the first electronic component and the second electronic component mounted on the same circuit board is radiated well only by the first resin portion and the second resin portion. A metal heat sink is not required and the structure can be simplified. Moreover, since the heat dissipation of the 1st resin part and the 2nd resin part is made to respond | correspond to the emitted-heat amount of a 1st electronic component and a 2nd electronic component, heat dissipation becomes inadequate also in a 1st resin part or a 2nd resin part. Don't worry.

  According to the control unit of the second and third aspects, since the first electronic component with a large calorific value is covered with the first resin part containing filler, heat can be radiated satisfactorily. Since the volume of the first storage space is small, an increase in weight due to the mixing of the filler hardly poses a problem.

  According to the control unit of the second invention, in the control unit in which the first electronic component is mounted on the first circuit board and the second electronic component is mounted on the second circuit board, basically the first The same effect as the invention can be obtained. According to the control units of the fifth and sixth aspects, basically the same effects as those of the second and third aspects can be obtained.

<Control unit>
The control unit of the present invention controls the operation of an electric device (for example, a DC motor, a starter motor, etc.), and includes a case, a circuit board on which electronic components are mounted, a resin portion, and the like.
<Case>
The case (housing) insulates the electronic components on the circuit board from peripheral devices and dissipates heat generated inside, and is made of an electrically insulating material (for example, PBT).

 Generally, it has a box shape, at least one wall portion is open, and the other wall portions define the accommodation space.

At least one partition is formed from one wall portion toward the opposing wall portion or between a pair of opposing wall portions, and the accommodating space is divided into two or more small spaces. When there is one partition, two small spaces (first housing space and second housing space) are partitioned, and when there are two partitions, three small spaces are partitioned. The position and number of partitions are determined in consideration of the shape of the circuit board and electronic components, the size and number of electronic components, and the like. The size and shape of the plurality of small spaces may be the same or different. It is desirable from the viewpoint of weight reduction to accommodate an electronic component with a large calorific value in a relatively small space and an electronic component with a small calorific value in a relatively small space.
<Circuit boards, electronic components>
The shape of the circuit board is determined by the relationship with the case, and the type, size and number of electronic components are determined by the application and function of the control unit. The electronic component is, for example, a power transistor, FET, transformer, resistor, or the like, and includes at least a first electronic component and a second electronic component. Electronic components are mounted only on the front surface of the circuit board or on the front and back surfaces.

In the present invention, the first electronic component housed in the first housing space and the second electronic component housed in the second housing space have different amounts of heat generation, and it is assumed that the former is more than the latter. When there are three or more electronic components with different calorific values, the same idea as in the case of two is followed.
<Heat dissipation resin part>
The plurality of resin parts constituting the heat dissipation resin part have different heat dissipation properties. The first resin portion filled in the first housing space of the case and the second resin portion filled in the second housing space have different heat dissipation properties. There are several ways to achieve different heat dissipation. In the first type, the first resin part is formed by mixing filler with soft resin, and the second resin part is formed only by soft resin. The material of the soft resin is, for example, a urethane resin or an epoxy resin, and silica, alumina or the like can be used as the filler.

  In the second type, both the first resin portion and the second resin portion are formed by mixing filler with soft resin, but the filler mixing ratio is changed (the amount of filler mixed into the first resin portion is changed to the second resin portion). To be more than that). Whether the first type or the second type, the amount of filler can be selected between 5 and 80% by weight. In the third type, the material of the soft resin is changed without mixing the filler.

  Since the heat-dissipating resin part dissipates heat generated by the electronic component, it is filled in the accommodation space so as to cover a specific area on the front surface and / or back surface of the circuit board on which the electronic component is mounted.

Embodiments of the present invention will be described below with reference to the accompanying drawings.
<First embodiment>
(Constitution)
As shown in FIGS. 1 and 2, the control unit includes a case 10, a circuit board 25, and a resin portion 35. Of these, the case 10 is made of aluminum and has a flat box shape with one side opening. A flat rectangular accommodation space 19 is defined by the upper wall portion 12 and the lower wall portion 13, the left side wall portion 15 and the right side wall portion 16, and the end wall portion 18.

  Side grooves 15 a and 16 a having a predetermined height and depth are formed on the inner surface of the left side wall portion 15 and the inner surface of the right side wall portion 16 over the entire length slightly below the intermediate portion in the height direction.

  A partition 20 is formed on the lower surface of the upper wall portion 12 closer to the left wall portion 15 than the middle portion in the left-right direction (width direction). The partition 20 is formed over the entire length of the upper wall portion 12, has a certain width, and the height of the lower end thereof corresponds to the side grooves 15a and 16a.

  The circuit board 25 has a thin plate rectangular shape, and the left edge is inserted and supported in the left groove 15a and the right edge is inserted and supported in the right groove 16a. A predetermined circuit pattern is formed on the front surface (upper surface) and the rear surface (lower surface) of the circuit board 25, and electronic components 27, 28 and 29 are mounted on the front surface. The left electronic component (for example, FET) 27 mounted on the left end portion 26a of the circuit board 25 has a small amount of heat generation, and the intermediate electronic component 28 and the right electronic component 29 (for example, control circuit) mounted on the intermediate portion 26b and the right end portion 26c. Has a large calorific value. The partition 20 is positioned between the left electronic component 27, the intermediate electronic component 28 and the right electronic component 29, and the lower end extends to near the surface of the circuit board 25.

  A predetermined width, a predetermined height, and a predetermined height defined by the left end portion 12a of the upper wall portion 12, the upper half 15b of the left side wall portion 15 and the end wall portion 18, the partition 20, and the left end portion 26a of the circuit board 25. The upper left resin portion 36 is filled in the upper left chamber 31 having a length (depth). The upper left resin portion 36 is a mixture of 43 wt% urethane resin and 57 wt% filler, and covers the left electronic component 27.

The upper wall portion 12 is divided into an intermediate portion 12b and a right end portion 12c, a right side wall portion 16 and an upper half 16b of the end wall portion 18, etc., a partition 20, and an intermediate portion 26b and a right end portion 26c of the circuit board 25. The upper right resin portion 37 is filled in the upper right chamber 32 having a predetermined width larger than that of the upper left chamber 31. The upper right resin portion 37 is made of urethane resin and covers the intermediate electronic component 28 and the right electronic component 29. Further, a lower and lower chamber 33 made of urethane resin is partitioned by a lower wall portion 13, a left side wall portion 15, a right side wall portion 16, a lower half 15 c of the end wall portion 18, and the like, and a circuit board 25. Resin portion 38 is filled.
(Assembly)
When the control unit is assembled, the circuit board 25 on which the electronic components 27 to 29 are mounted in advance is inserted into the left side wall portion 15 and the side grooves 15a and 16a of the right side wall portion 16 from the opening side of the case 10. Then, the storage space 19 is partitioned into an upper left chamber 31, an upper right chamber 32 and a lower chamber 33, the left electronic component 27 is stored in the upper left chamber 31, and the intermediate electronic component 28 and the right electronic component 29 are in the upper right chamber 32. Is housed in.

Next, when a molten urethane resin containing filler is poured into the upper left chamber 31 and cured, the upper left resin portion 36 is obtained. When molten urethane resin is poured into the upper right chamber 32 and the lower chamber 33 and cured, the upper right resin portion 37 and the lower resin portion 38 are obtained.
(Function)
This control unit is used for controlling a motor in a motorcycle. During operation, the electronic components 27 to 29 generate heat, the left electronic component 27 generates a relatively large amount of heat, and the intermediate electronic component 28 and the right electronic component 29 generate relatively small amounts of heat. Heat generated by the left electronic component 27 is radiated by the upper left resin portion 36 and the case 10, and heat generated by the intermediate electronic component 28 and the right electronic component 29 is radiated by the upper right resin portion 37 and the case 10. The heat from the electronic components 27 to 29 is also slightly radiated from the lower resin portion 38.
(effect)
According to this control unit, the upper left resin portion 36 is excellent in heat dissipation by mixing a filler with urethane resin, so that heat generated by the left electronic component 27 can be radiated well. Since the intermediate electronic component 28 and the right electronic component 29 have a small amount of heat radiation, the heat radiation at the upper right resin portion 37 made of urethane resin does not become insufficient. In this way, heat radiation can be achieved only by the resin portion 35 without providing a heat radiating plate as in the above-described conventional example, and a temperature rise exceeding the limit of the electronic components 27 to 29 can be prevented with a simple structure with a small number of components. did it.

Further, the upper left resin portion 36 containing filler is heavier per unit volume than the upper right resin portion 37 made only of urethane resin, but the volume of the upper left space 31 is small, so an increase in weight is almost a problem. Don't be. In addition, since the partition 20 is formed in the case 10, the volume of the partition 20 and the upper left resin part 36 volume are reduced, and the weight can be reduced.
<Second embodiment>
(Constitution)
The second embodiment shown in FIG. 3 is different from the first embodiment in that the housing space of the case is completely divided into two by the partition, and the other configurations are the same. In the following, different configurations will be mainly described.

  A partition 55 is formed from the lower surface of the upper wall portion 12 of the case 50 to the upper surface of the lower wall portion 13 in the left-right direction (width direction) closer to the left side wall portion 15 than the intermediate portion, and the left side accommodation space 56a and the right side accommodation space 56b. Is partitioned. The partition 55 is formed over the entire length of the upper wall portion 12 and the lower wall portion 13, and side grooves 57 and 58 are formed on the left side surface and the right side surface thereof.

  The left circuit board 60 accommodated in the left accommodating space 56a has a small thin plate rectangular shape, and the left edge is inserted and supported in the side groove 15a of the left wall 15 and the right edge is inserted and supported in the side groove 57 of the partition 55. An electronic component 62 having a relatively large amount of heat generation is mounted on the surface of the left circuit board 60. The right circuit board 65 accommodated in the right accommodation space 56b has a large thin plate rectangular shape, and the left edge is inserted and supported in the side groove 58 of the partition 55, and the right edge is inserted and supported in the side groove 16a of the right wall portion 16. An intermediate electronic component 66 and a right electronic component 67 with a relatively small amount of heat generation are mounted on the surface of the right circuit board 65.

  The left end of the upper wall portion 12, the lower wall portion 13 and the end wall portion 18, the left side wall portion 15, the partition 55, and the left side circuit board 60 are above and below the left side circuit board 60, respectively. A lower left space 74 is formed. The upper left space 71 is filled with the upper left resin portion 72, and the lower left space 74 is filled with the lower left resin portion 75. The upper left resin part 72 and the left lower resin part 75 are formed by mixing 43% by weight of urethane resin and 57% by weight of filler.

  The middle and right end portions of the upper wall portion 12, the lower wall portion 13 and the end wall portion 18, the right side wall portion 16, the partition 55, and the right side circuit board 65 are respectively located above and below the right side circuit board 65. A right space 77 and a lower right space 81 are formed. The upper right resin portion 79 filled in the upper right space 77 and the lower right resin portion 82 filled in the lower right space 81 are both made of urethane resin.

  When the control unit is assembled, the left circuit board 60 is inserted into the left housing space 56a to fill the left resin parts 72 and 74, and the right circuit board 65 is inserted into the right housing space 56b to insert the right resin parts 77 and 81. Fill.

  According to this control unit, the following specific effects can be obtained in addition to the effects of the first embodiment. First, the heat generated by the left circuit board 60 is positively dissipated from the lower left resin portion 75 having a large heat dissipation property. Further, since the partition 55 extends from the upper wall portion 12 to the lower wall portion 13, the left resin portions 72 and 74 and the right resin portions 77 and 81 are not mixed when the resin is injected.

1 is a perspective view showing a first embodiment of the present invention. It is a front sectional view similarly. It is front sectional drawing which shows 2nd Example. It is front sectional drawing which shows a prior art example.

Explanation of symbols

10: Case 12: Upper wall portion 13: Lower wall portion 15, 16: Side wall portion 20: Partition 25: Circuit board 27: First electronic component 28, 29: Second electronic component 31: First housing space 32: Second Housing space 36: first resin part 37: second resin part

Claims (6)

An insulating case defining at least two housing spaces;
One circuit board on which the first electronic component housed in the first housing space of the case and having a relatively large amount of heat generation and the second electronic component housed in the second space and having a relatively small amount of heat generation are mounted;
A first resin portion filled in the first housing space and covering the first electronic component and having a relatively large heat dissipation property;
A second resin part that is filled in the second housing space and covers the second electronic component and has relatively low heat dissipation;
A control unit comprising:   2. The control unit according to claim 1, wherein the first resin portion is made of a soft resin and a filler, and the second resin portion is made of a soft resin.   The control unit according to claim 2, wherein a volume of the first resin portion is smaller than a volume of the second resin portion. An insulating case having at least two accommodation spaces partitioned by a partition;
A first circuit board mounted with a first electronic component housed in the first housing space of the case and having a relatively large calorific value;
A first resin portion filled in the first housing space and covering the first electronic component and having a relatively large heat dissipation property;
A second circuit board mounted with a second heating element housed in the second housing space of the case and having a relatively small amount of heat generation;
A second resin part that is filled in the second housing space and covers the second electronic component and has relatively low heat dissipation;
A control unit comprising:   The control unit according to claim 4, wherein the first resin portion is made of a soft resin and a filler, and the second resin portion is made of a soft resin.   The control unit according to claim 5, wherein a volume of the first resin portion is smaller than a volume of the second resin portion.

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