JP5155914B2 - Controller unit - Google Patents

Description

  The present invention relates to a control unit configured by housing a printed circuit board on which electronic components are mounted in a housing.

  In Patent Document 1, for example, a silicon-based gel-like resin material (thermal conductive material) containing a metal filler is disposed between a protrusion provided on a housing and a printed board, and mounted on the printed board. An electronic control device is disclosed in which heat generated in the electronic component is radiated through the heat conducting material and the housing.

JP 2003-289191 A

  By the way, in the heat dissipation structure that dissipates the heat of the electronic component through the heat conductive material as described above, when the heat conductive material is applied to each individual electronic component, the number of application points in the coating device increases and work efficiency deteriorates. In addition, there is a problem that the amount of heat conductive material used increases.

  This invention is made | formed in view of the said situation, and it aims at enabling it to apply | coat a heat conductive material efficiently and to reduce the usage-amount of a heat conductive material.

Therefore, in the present invention, a plurality of electronic components integrally provided with a heat sink are arranged on a printed circuit board so that the respective heat sinks face each other close to each other, and the plurality of electronic components are mounted. A heat conduction material is filled in a gap between the printed circuit board on the side and the housing, which is sandwiched between the opposed heat sinks .

According to the above invention, since the space between the printed circuit board on the side where the plurality of electronic components are mounted and the housing is filled with the heat conductive material in the region sandwiched between the opposed heat sinks, Compared with the case where the application operation is individually performed on the electronic component, the application point of the heat conducting material can be reduced, and the amount of the heat conducting material used can be reduced.

It is a fragmentary sectional view showing a 1st embodiment of a control unit concerning the present invention. It is a top view of the printed circuit board in the first embodiment. It is a figure which shows the semiconductor chip in the said 1st Embodiment. It is a figure which shows another example of the arrangement pattern of a semiconductor chip. It is a figure which shows another example of the arrangement pattern of a semiconductor chip. It is a fragmentary sectional view showing a 2nd embodiment of a control unit concerning the present invention. It is a top view of the printed circuit board in the second embodiment. It is a fragmentary sectional view showing a 3rd embodiment of a control unit concerning the present invention. It is a fragmentary sectional view showing a 4th embodiment of a control unit concerning the present invention. It is a fragmentary sectional view showing a 5th embodiment of a control unit concerning the present invention. It is a fragmentary sectional view showing a 6th embodiment of a control unit concerning the present invention. It is a fragmentary sectional view showing a 7th embodiment of a control unit concerning the present invention.

Embodiments of the present invention will be described below.
1 and 2 show a first embodiment of a control unit according to the present invention, and FIG. 1 is a cross-sectional view taken along line AA of FIG.

  A control unit 100 shown in the figure is, for example, disposed in an engine room and used for vehicle control, and includes a printed circuit board 400 on which a plurality of electronic components such as a semiconductor chip 200 and an aluminum electrolytic capacitor 300 are mounted, It is comprised from the housing | casing 500 which accommodates the printed circuit board 400. FIG.

  The semiconductor chip 200 described in the present embodiment is an electronic component that generates a large amount of heat, and as shown in FIG. 3, the lead 202 is taken out from the side surface 201, and on the opposite side surface 203 parallel to the side surface 201. Is provided with a protruding heat sink 204 that is a heat sink for dissipating the heat of the semiconductor chip 200.

  The casing 500 has a substantially square box shape, and is composed of two parts, a case 501 that is open on one side and a cover 502 that closes the open side of the case 501, and forms a space for accommodating the printed circuit board 400. To do.

  The printed circuit board 400 is installed with a gap S1 between the bottom surface 505 of the case 501 and the back surface (non-mounting surface in the present embodiment) 401 of the printed circuit board 400 so as to cover the open portion of the case 501. Further, a cover 502 is attached and fixed to the case 501 with a screw or the like not shown.

Electronic components can also be mounted on the back surface of the printed circuit board 400.
Then, with the cover 502 attached, a gap S2 of at least the minimum value min is secured between the inner surface 506 of the cover 502 and the electronic components such as the semiconductor chip 200 and the aluminum electrolytic capacitor 300. Yes.

  The minimum value min is set to a value that prevents the electronic component from hitting the cover 502 in consideration of dimensional variations of the casing 500 (case 501 and cover 502) and electronic components, bending / vibration of the printed circuit board 400, and the like. .

The case 501 and the cover 502 are made of a metal such as aluminum.
A plurality of fins (heat sinks) 504 are integrally formed on the surface 503 of the cover 502 to dissipate heat of the semiconductor chip 200 and the like transmitted to the cover 502 into the atmosphere.

Note that a water cooling system in which heat is transferred to the liquid (water) through the fins 504 and the heat of the liquid (water) is released into the atmosphere can be employed.
A plurality of the semiconductor chips 200 are mounted on the surface 402 (mounting surface) of the printed circuit board 400, but the heat sinks 204 of the adjacent semiconductor chips 200 are disposed close to each other as far as possible in arrangement ( A plurality of semiconductor chips 200 are arranged so as to face each other.

For example, the first semiconductor chip 200a and the second semiconductor chip 200b are disposed on the printed circuit board 400 so that the heat radiating plates 204 face each other in parallel and close to each other.
Further, the third semiconductor chip 200c to the fifth semiconductor chip 200e are arranged linearly with the side surfaces 205 where the leads 202 and the heat dissipation plate 204 are not provided close to each other, and one side in the arrangement direction (left side in FIG. 2). Are disposed on the printed circuit board 400 such that the lead 202 is disposed on the other side (the right side in FIG. 2) and the heat sink 204 is disposed on the other side.

  Further, the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are disposed on the printed circuit board 400 so that the heat sinks 204 face each other in parallel and close to each other, and the third semiconductor chip 200c˜ The side surfaces 205 of the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are arranged on the side where the heat sink 204 of the fifth semiconductor chip 200e is arranged, and the heat sinks of the third semiconductor chip 200c to the fifth semiconductor chip 200e, respectively. It is arranged on the printed circuit board 400 so as to face and close to 204.

The arrangement of the semiconductor chips 200 with the heat sinks 204 facing each other in proximity is not limited to the example shown in FIG.
For example, as shown in FIG. 4, the side surfaces 205 where the leads 202 and the heat sink 204 are not provided are linearly arranged close to each other, the leads 202 are arranged on one side of the arrangement direction, and the other side Similarly to the arrangement of the plurality of semiconductor chips 200 in which the heat sink 204 is arranged on the side, similarly, the side surfaces 205 where the leads 202 and the heat sink 204 are not provided are arranged in a straight line, and A plurality of semiconductor chips 200 arranged such that a lead 202 is arranged on one side of the arrangement direction and a heat radiating plate 204 is arranged on the other side, the heat radiating plates 204 face each other in parallel. It can be arranged on the printed circuit board 400.

  In addition, as shown in FIG. 5, a plurality of semiconductor chips 200 can be arranged concentrically with the heat sink 204 as the center, and the number of semiconductor chips 200 arranged on the concentric circles is 3, 4 to 5 or more. Either may be sufficient.

  That is, the configuration in which the heat sinks 204 are close to each other is not limited to the arrangement in which the heat sinks 204 are opposed to each other in parallel, but includes that they are opposed to each other with an inclination, in other words, another heat release on the extension of one heat sink 204. A plurality of semiconductor chips 200 may be arranged so that the plate 204 exists.

  Furthermore, an electronic component that generates heat and includes a heat sink is not limited to a semiconductor chip, and the shape of the heat sink is not limited to a plate-like shape. For example, an electronic component that includes a fin-shaped heat sink It may be a part.

  The semiconductor chip 200 arranged on the printed circuit board 400 as described above is a heat-generating component as described above, and the heat from the heat radiating plate 204 is efficiently released to suppress the temperature rise of the semiconductor chip 200. Can do.

  Therefore, in the present embodiment, the gap S2 between the heat radiating plate 204 and the cover 502 is a flexible gel-like (semi-solid, paste-like) heat conduction material, which is higher than air. The silicon grease 600 indicating the thermal conductivity is interposed, and the heat of the heat radiating plate 204 is transmitted to the cover 502 through the silicon grease 600, and the heat transmitted to the cover 502 is radiated to the atmosphere by the fins 504. .

  In the present embodiment, the silicon grease 600 is used as a flexible heat conductive material. However, the silicon grease 600 may be a mixture of silver powder or aluminum powder. An oil compound in which silica powder is blended with silicon oil as a base oil, or a thermal compound obtained by mixing a metal oxide having good thermal conductivity with ester-based synthetic grease to obtain heat dissipation can be used.

The silicon grease 600 is applied to the printed circuit board 400 using a coating apparatus (application robot) with the printed circuit board 400 attached to the case 501.
Here, in the present embodiment, as shown in FIG. 2, the silicon grease 600 is applied to the first semiconductor chip 200a and the second semiconductor chip 200b at a substantially central portion of the region where the heat radiating plates 204 face each other. Similarly, with respect to the sixth semiconductor chip 200f and the seventh semiconductor chip 200g, the mutual heat sinks 204 are applied to substantially the central part of the facing region.

  Further, with respect to the third semiconductor chip 200c to the fifth semiconductor chip 200e, the silicon grease 600 is provided at a substantially central portion of the region where the respective heat sinks 204 and the side surfaces 205 of the sixth semiconductor chip 200f and the seventh semiconductor chip 200g face each other. Is applied.

  Then, after applying the silicon grease 600, the cover 502 is attached to the case 501, thereby crushing the silicon grease 600 with the cover 502 applied in a mountain shape, and as shown in FIG. A region between the substrate 400 and the gap between the semiconductor chip 200 and a gap between the heat sink 204 side of the upper surface 206 of the semiconductor chip 200 and the cover 502 is filled with silicon grease 600, and the silicon grease 600 is filled with the heat sink 204. And the cover 502 are brought into close contact with each other.

As a result, the silicon grease 600 is in close contact with the heat radiating plate 204 and the cover 502, and the heat of the heat radiating plate 204 is transmitted to the cover 502 via the silicon grease 600.
Accordingly, more heat is transferred to the cover 502 (fins 504) than when the heat of the heat radiating plate 204 is transmitted to the cover 502 via air, and a high heat dissipation effect is exhibited.

  Further, since the silicon grease 600 has flexibility, for example, the silicon grease 600 is printed by vibration (for example, due to vehicle vibration) or deformation (for example, warpage generated in the printed circuit board 400 due to temperature) of the printed circuit board 400. There is no load on the substrate 400.

  Incidentally, as described above, the first semiconductor chip 200a and the second semiconductor chip 200b, and further, the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are disposed so that the heat sinks 204 face each other. By applying the silicon grease 600 to the substantially central portion of the region, the silicon grease 600 can be interposed between the heat sink 204 and the cover 502 for each of the two semiconductor chips 200 facing each other.

  For example, when the first semiconductor chip 200a and the second semiconductor chip 200b are arranged in the same direction, such as when the heat radiating plates 204 are arranged so as not to face each other, the silicon grease 600 is changed to the first one. It is necessary to apply each of the first semiconductor chip 200a and the second semiconductor chip 200b individually.

  On the other hand, if the first and second semiconductor chips 200a and 200b, and the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are arranged so that the mutual heat sinks 204 are close to each other, By applying silicon grease 600 to the central portion of the opposing region, a heat dissipation structure in which the silicon grease 600 is interposed can be formed for each semiconductor chip 200.

  Therefore, compared with the case where the silicon grease 600 is applied to each semiconductor chip 200, the application point of the silicon grease 600 can be reduced, the efficiency of the application work can be increased, and the amount of the silicon grease 600 to be applied can be reduced. .

  As described above, in order to reduce the application point, the heat radiating plate 204 is brought close to and opposed to each other. Therefore, the proximity of the heat radiating plate 204 means that each heat radiating plate is a common application point with respect to the opposing semiconductor chip 200. It means that the silicon grease 600 necessary for heat transfer from 204 can be applied.

  The arrangement of the semiconductor chips 200 as shown in FIG. 4 can be regarded as a continuation of the arrangement of the first semiconductor chip 200a and the second semiconductor chip 200b, or the sixth semiconductor chip 200f and the seventh semiconductor chip 200g. The number of application points of the silicon grease 600 may be increased along the direction in which the facing region extends.

Further, as shown in FIG. 5, when a plurality of semiconductor chips 200 are arranged concentrically with the heat sink 204 side as the center, silicon grease 600 is applied in the vicinity of the center of the concentric circle.
6 and 7 show a second embodiment of the present invention, in which a wall-like projecting portion 507 projecting from the inner surface 506 of the case 502 toward the substantially central portion of the region where the heat sink 204 is disposed is provided. This is different from the first embodiment.

  The protrusion 507 includes a first protrusion 507a extending along a central portion of a region where the first semiconductor chip 200a and the second semiconductor chip 200b are disposed, and a sixth semiconductor chip 200f and a seventh semiconductor chip 200g. The second projecting portion 507b extends along the central portion of the region where the is disposed.

  Furthermore, the heat sinks 204 of the third semiconductor chip 200c to the fifth semiconductor chip 200e and the side surfaces 205 of the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are extended along substantially the central part. The third protrusion 507c may be formed.

  When forming the third protrusion 507c, the third protrusion 507b can be a T-shaped protrusion integral with the second protrusion 507b, and the second protrusion 507b and the third protrusion 507c can be made independent of each other. Can be formed.

  The protrusion 507 is set to have a width W that does not interfere with the semiconductor chip 200 (heat radiating plate 204), and the interference with the printed circuit board 400 between the tip 508 and the surface 402 (mounting surface) of the printed circuit board 400. The height H from the inner surface 506 of the case 502 is set so as to provide a gap S3 for preventing this.

In the case where the protrusions 507a and 507b (507c) are provided, the following effects are obtained in addition to the effects of the first embodiment.
According to the second embodiment, when the cover 502 is attached to the case 501 after the silicon grease 600 is applied, the protrusions 507a and 507b divide the center of the silicon grease 600 applied in a mountain shape. Since the silicon grease 600 is pushed toward both of the semiconductor chips 200 arranged opposite to each other, the silicon grease 600 applied to the central portion of the opposed region is distributed to each semiconductor chip 200 and silicon silicon The bias of the grease 600 can be suppressed.

  Further, since the silicon grease 600 can be pressed against the heat radiating plate 204 of each semiconductor chip 200 by the protrusions 507a and 507b (507c), the adhesion of the silicon grease 600 to the heat radiating plate 204 can be increased.

  Furthermore, since the protrusions 507a and 507b (507c) transfer the heat of the silicon grease 600 to the fins 504 and the protrusions 507 are located near the heat dissipation plate 204, the heat dissipation path 204 covers the cover 502. It acts similarly to the case where the distance to is shortened, and the heat radiation efficiency can be increased.

  Further, since the protruding portions 507a and 507b (507c) occupy a part of the space volume facing the semiconductor chip 200, it is possible to reduce the application amount (use amount) of the silicon grease 600 accordingly. Become.

  FIG. 8 shows a third embodiment of the present invention. In contrast to the second embodiment, the height of the protruding portion 507 is set to a length through which the tip 508 of the protruding portion 507 penetrates the printed circuit board 400. The difference is that a through-hole 403 (slit) through which the tip 508 of the protruding portion 507 is inserted is opened in the printed circuit board 400.

  In the third embodiment, the through hole 403b having a width and a length through which the tip 508 of the protruding portion 507b can be inserted along the central portion of the region where the sixth semiconductor chip 200f and the seventh semiconductor chip 200g are opposed to each other. It is formed on the printed circuit board 400.

  Although not shown in the drawings, a through hole having a width and a length through which the tip 508 of the protruding portion 507a can be inserted along the central portion of the region where the first semiconductor chip 200a and the second semiconductor chip 200b are opposed to each other. Furthermore, when the protruding portion 507c is formed, a through hole having a width and a length through which the protruding portion 507c can be inserted is formed in the same manner as the through hole 403b.

  On the other hand, the protrusion 507b has a height from the inner surface 506 of the case 502 so as to penetrate the through hole 403b and the tip 508 thereof is substantially flush with the back surface 401 of the printed circuit board 400. It is assumed that the same height is set for the protrusions 507a and 507c.

  According to the third embodiment, the protrusions 507b (507a, 507c) are arranged closer to the heat sink 204 while suppressing the interference between the printed circuit board 400 and the protrusions 507b (507a, 507c). Thus, a higher heat dissipation effect can be obtained, and the amount of silicon grease 600 can be further reduced.

  In other words, the closer the tip 508 of the protruding portion 507b (507a, 507c) is to the surface 402 (mounting surface) of the printed circuit board 400, the shorter the distance between the protruding portion 507b (507a, 507c) and the heat sink 204 is. 204 can efficiently transfer heat from the protrusions 507b (507a, 507c) to the protrusions 507b (507a, 507c). However, if the distance between the protrusions 507b (507a, 507c) and the printed circuit board 400 is short, the protrusions may be caused by dimensional variations or vibrations. There is a possibility that the tips 508 of 507a and 507b hit the printed circuit board 400 and apply a load to the printed circuit board 400.

  On the other hand, as in the third embodiment, if the protruding portion 507b (507a, 507c) penetrates the printed circuit board 400, the protruding portion 507b ( 507a, 507c) and the printed circuit board 400 do not interfere with each other, and the distance between the protrusion 507b (507a, 507c) and the heat sink 204 can be set to the shortest, thereby applying a load to the printed circuit board 400. Without any problem, the heat dissipation effect can be enhanced and the application amount (use amount) of the silicon grease 600 can be reduced as compared with the second embodiment.

  As described above, when the through hole 403b is opened in the printed circuit board 400, the viscosity of the silicon grease 600 and / or the opening width of the through hole 403b (the width of the protruding portion 507b) is adjusted, and the cover 502 is assembled. It is preferable to suppress the outflow of the silicon grease 600 from the through hole 403b at the previous stage.

In FIG. 8, the height of the protrusion 507 (507a, 507c) is set so that the tip 508 of the protrusion 507b (507a, 507c) is substantially flush with the back surface 401 of the printed circuit board 400.
As in the fourth embodiment shown in FIG. 9, the protrusions 507 b (507 a and 507 c) are inserted into the through holes 403 b provided in the printed circuit board 400, and the tip 508 of the protrusion 507 abuts against the bottom surface 505 of the case 501. The height of the protruding portion 507b (507a, 507c) can be set.

  As described above, when the tip 508 of the protrusion 507b (507a, 507c) is brought into contact with the bottom surface 505 of the case 501, the print 507b (507a, 507c) includes the cover 502 and the case 501. It functions as a wall that supports the accommodation space of the substrate 400 in the vertical direction, and the bending of the cover 502 and the case 501 to the printed circuit board 400 side is suppressed.

  Therefore, the bottom surface 505 of the case 501 is suppressed while suppressing the occurrence of interference between the cover 502 and the case 501 and the printed circuit board 400 and a plurality of electronic components such as the semiconductor chip 200 and the aluminum electrolytic capacitor 300 mounted on the printed circuit board 400. And the printed board 400 (or electronic component) can be reduced, and the gap between the inner surface 506 (ceiling surface) of the cover 502 and the electronic component can be reduced.

  As a result, the control unit 100 can be thinned, the heat transfer path through the silicon grease 600 can be shortened to increase the heat dissipation efficiency, and the amount of the silicon grease 600 used can be reduced.

  By the way, if the flexible gel-like heat conductive material such as the silicon grease 600 is moved from the region where the semiconductor chip 200 is disposed due to vibration, gravity, or the like, the heat dissipation plate 204 faces the cover 502. In this heat transfer path, air having a low thermal conductivity is interposed, so that the heat dissipation performance is deteriorated.

A fifth embodiment provided with means for preventing the silicon grease 600 from flowing out will be described with reference to FIG.
In the fifth embodiment shown in FIG. 10, at least an application region of the silicon grease 600 is provided on the inner surface 506 (ceiling surface) of the cover 502 as a means for preventing the silicon grease from flowing out with respect to the control unit 100 of the first embodiment. The difference is that the surrounding wall is formed.

  In FIG. 10, the inner surface 506 of the cover 502 (on the both sides of the central portion of the region where the heat sinks 204 of the sixth semiconductor chip 200f and the seventh semiconductor chip 200g face each other and near the boundary of the application region of the silicon grease 600) A pair of walls 510a and 510b are formed so as to protrude from the ceiling surface.

  Although not shown in the figure, the inner surface 506 (ceiling surface) of the cover 502 is similarly formed on both sides of the central portion of the region where the heat sinks 204 of the first semiconductor chip 200a and the second semiconductor chip 200b face each other. A pair of protruding walls are formed.

  The heights H <b> 1 of the walls 510 a and 510 b are set so as to ensure a gap that is large enough to avoid interference with the semiconductor chip 200.

  By providing the walls 510a and 510b, the silicon grease 600 is prevented from flowing out over the semiconductor chip 200 due to vibration, gravity, or the like, and the desired heat dissipation performance can be maintained.

  In the fifth embodiment shown in FIG. 10, walls 510a and 510b for preventing the outflow of the silicon grease 600 are provided in the first embodiment. However, as in the sixth embodiment shown in FIG. Walls 510a and 510b similar to those in the fifth embodiment can be provided in the second embodiment in which the protruding portion 507 that protrudes toward the substantially central portion of the region where the heat radiating plate 204 faces is formed.

That is, in the sixth embodiment, the pair of walls 510a and 510b are formed on both sides of the protruding portion 507b so as to be substantially parallel to the protruding portion 507b.
In the sixth embodiment, when the cover 502 is attached to the case 501, the protruding portion 507 b (507 a) functions to push the silicon grease 600 toward both the semiconductor chips 200 facing each other. As a result of the flow of the silicon grease 600 toward the semiconductor chip 200 being suppressed by the walls 510a and 510b, the pressure increases in the silicon grease 600 in the opposing region of the semiconductor chip 200 (in the region sandwiched between the walls 510a and 510b), After the opposing region is filled with the silicon grease 600, the excess silicon grease 600 flows along the extending direction of the protrusions 507.

  Therefore, the walls 510a and 510b function to suppress the outflow of the silicon grease 600 after assembly, and also function to increase the filling performance of the silicon grease 600 in the facing region of the semiconductor chip 200 when the cover 502 is assembled.

  Note that the walls 510a and 510b can be added even in the configuration in which the protruding portion 507 penetrates the printed circuit board 400 as in the third embodiment or the fourth embodiment. This is the same as in the sixth embodiment.

The walls 510a and 510b are formed on both sides sandwiching the central portion of the region where the heat sink 204 is opposed, but as shown in the seventh embodiment of FIG. The wall 511 for suppressing the outflow of the silicon grease 600 can be formed so as to surround the application region of the silicon grease 600. Specifically, the heat sinks 204 of the first semiconductor chip 200a and the second semiconductor chip 200b are opposed to each other. A pair of walls 511a and 511b are arranged to face each other on both sides, and the third semiconductor chip 200c to the fifth semiconductor chip 200e in a region where the heat sinks 204 of the sixth semiconductor chip 200f and the seventh semiconductor chip 200g face each other. A wall 511c is formed on the side opposite to the side.

  Further, in the example shown in FIG. 12, the silicon grease 600 that transfers heat from the third semiconductor chip 200c to the fifth semiconductor chip 200e also flows out to both ends in the arrangement direction of the third semiconductor chip 200c to the fifth semiconductor chip 200e. A pair of walls 511d and 511e for suppression are formed.

  The heights of the walls 511a to 511e from the inner surface 506 (ceiling surface) of the cover 502 are set so that the walls 511a to 511e are close to the printed circuit board 400 with a minimum gap that can avoid interference between the front end and the printed circuit board 400.

  If it is the structure provided with the said walls 511a-511e, the outflow of the silicon grease 600 toward the side from the area | region which the heat sink 204 opposes will be suppressed, and expected heat dissipation performance can be maintained.

  The walls 511a to 511e can be added to the configuration including the protruding portion 507, and the walls 510a and 510b for suppressing the silicon grease 600 from flowing out over the semiconductor chip 200, and the heat sink Walls 511a to 511e that suppress the outflow of silicon grease 600 from the region facing 204 to the side can be provided in combination.

In addition, the application region of the silicon grease 600 can be surrounded over the entire circumference by a wall that protrudes from the inner surface 506 (ceiling surface) of the cover 502.
Furthermore, it is also possible to use a wall that protrudes from the inner surface 506 (ceiling surface) of the cover 502 and, for example, a gasket seal (FIPG) that applies a liquid gasket to a portion requiring sealing and hardens it. It is.

  Further, the semiconductor chip 200 in each embodiment is disposed in the vicinity of the outer edge portion of the printed circuit board 400, so that the housing 500 is positioned in a position near the heat radiating plate 204, so that the distance of the heat conduction path is shortened and the heat dissipation. The effect can be enhanced.

  DESCRIPTION OF SYMBOLS 100 ... Control unit, 200 ... Semiconductor chip (electronic component), 204 ... Heat sink (heat sink), 400 ... Printed circuit board, 403 ... Through-hole, 500 ... Housing, 501 ... Case, 502 ... Cover, 504 ... Fin, 507 ... Projections, 510a, 510b ... walls, 511a to 511e ... walls, 600 ... silicone grease (heat conducting material)

Claims (3)

In a control unit having a plurality of electronic components integrally provided with a heat sink, a printed circuit board on which the plurality of electronic components are mounted, and a housing for housing the printed circuit board,
Arranging the plurality of electronic components on the printed circuit board so that the respective heat sinks face each other in close proximity ; and
A control unit comprising a gap between the printed circuit board on the side where the plurality of electronic components are mounted and the housing, and a region sandwiched between the opposed heat sinks filled with a heat conductive material . The control unit according to claim 1 , wherein a projecting portion that projects toward the region and extends into the heat conductive material is provided on an inner surface of the housing. The control unit according to claim 1, wherein a wall surrounding a region filled with the heat conductive material is provided on an inner surface of the housing.

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