Electronic control device

Abstract

The present invention provides an electronic control device in which it is possible to efficiently suppress, with few electronic components, unnecessary electromagnetic radiation without interfering with wiring around the components and mounting of the components.　Provided is an electronic control device 101 comprising a circuit board 102 on which an electronic component 201 is mounted and housings 103 and 104 in which the circuit board 102 is housed, wherein: the circuit board 102 has a GND pattern; the housing 103 has a first protruding part 301 and a second protruding part 302 which are electrically conductive and which protrude toward the circuit board 102; the first protruding part 301 is connected to the electronic component 201; the second protruding part 302 has a first connection part which is connected to the outer peripheral surface of the first protruding part 301 and a second connection part 303 which is connected to the GND pattern directly or with the connection member 203 therebetween; and the second protruding part 302 is shaped such that, between the electronic component 201 and the second connection part 303, a protruding surface of the second protruding part 302 is as close to the circuit board 102 as or closer to the circuit board 102 than a protruding surface of the first protruding part 301.

Description

Electronic control unit

[0001] The present invention relates to an electronic control device.

[0002] Electronic control devices for driver assistance systems and autonomous driving need to process large volumes of information from sensor modules such as cameras at high speed, so they tend to be equipped with high-performance LSIs.

[0003] As LSI performance improves, high-frequency noise increases, and noise is more easily transmitted through heat dissipation paths, which increases unwanted electromagnetic radiation.In addition, external noise can also be transmitted via these paths, which reduces noise resistance.

[0004] FIG. 2 and other figures of Patent Document 1 show a structure that confines noise within a metal housing and suppresses unnecessary electromagnetic radiation by providing a structure that connects the housing and the GND pattern of the board near an external connection connector, which is a likely path for noise to be transmitted from inside the device to the outside.

[0005] Furthermore, in FIG. 3 and other figures of Patent Document 2, a structure is shown in which a conductive point is provided between a metal housing and a substrate so as to surround electronic components including an LSI, thereby enhancing the electromagnetic shielding effect.

[0006] JP 2022-173233 A JP 2005-294627 A

[0007] The technology of Patent Document 1 prevents noise transmitted from the LSI to the housing via the heat dissipation path from reaching the area around the connector, which is an opening in the housing, by surrounding the area around the connector and thereby suppressing noise from escaping through the opening in the housing around the connector.

[0008] However, the technology of Patent Document 1 requires that the GND pattern of the board and the housing be joined so as to surround the connector. Therefore, if the number of connectors increases along with the increase in sensors and other devices connected to the device, a large number of components and materials such as EMI gaskets will be required to surround all the connectors, resulting in the problem of increased costs.

[0009] To achieve electromagnetic shielding using fewer components, it is desirable to construct a shielding structure near the noise source before the noise from the LSI spreads inside the housing, and the technology disclosed in Patent Document 2 is one example of such a structure.

[0010] However, a large number of signal wiring and components need to be placed near the LSI, and creating a conductive point with the housing near the LSI, as in the technology of Patent Document 2, hinders the placement of wiring and components, which places constraints on board design and leads to an increase in board size and the number of board layers, resulting in problems such as increased costs.

[0011] The problem to be solved by the present invention is to provide an electronic control device that can efficiently suppress unwanted electromagnetic radiation with a small number of components without interfering with the wiring around the electronic components or the mounting of the components.

[0012] In order to solve the above-mentioned problems, the electronic control device of the present invention is an electronic control device having a circuit board mounted with electronic components and a housing that houses the circuit board, wherein the circuit board has a GND pattern, the housing has conductive first and second convex portions that are convex toward the circuit board side, the first convex portion is connected to the electronic component, the second convex portion has a first connection portion connected to the outer peripheral surface of the first convex portion and a second connection portion connected to the GND pattern directly or via a connection member, and the second convex portion is shaped so that, between the electronic component and the second connection portion, the convex surface of the second convex portion is as close to the circuit board as or closer to the convex surface of the first convex portion.

[0013] According to the electronic control device of the present invention, unwanted electromagnetic radiation can be efficiently suppressed with a small number of components without interfering with wiring around electronic components or component mounting.

[0014] 1 is a cross-sectional view of an electronic control device of Example 1. FIG. 2 is a plan view of a housing base of the electronic control device of Example 1. FIG. 3 is a perspective view of the housing base of the electronic control device of Example 1. FIG. 4 is a perspective view of the electronic control device of Example 1. FIG. 5 is a plan view of a housing base of the electronic control device of Example 2. FIG. 6 is a cross-sectional view of an electronic control device of Example 3. FIG. 7 is a plan view of a housing base of the electronic control device of Example 4. FIG. 8 is a cross-sectional view of an electronic control device of Example 5. FIG. 9 is a plan view of a housing base of an electronic control device of Example 6. FIG. 10 is a perspective view of a noise guide structure of an electronic control device of Example 7. FIG. 11 is a cross-sectional view of an electronic control device of Example 8. FIG. 12 is a plan view of a housing base of an electronic control device of Example 9. FIG. 13 is a plan view of a housing base of an electronic control device of Example 10. FIG. 14 is a cross-sectional view of an electronic control device of Example 11. FIG. 15 is a cross-sectional view of an electronic control device of Example 12.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In each drawing and each embodiment, the same or similar components are designated by the same reference numerals, and redundant explanations will be omitted.

[0016] FIG. 1 is a cross-sectional view of the electronic control device of the first embodiment. FIG. 2 is a plan view of the housing base of the electronic control device of the first embodiment. FIG. 3 is a perspective view of the housing base of the electronic control device of the first embodiment. FIG. 4 is a perspective view of the electronic control device of the first embodiment. In FIGS. 1 and 2, only the essential parts of this embodiment are shown in a simplified manner. The cross-sectional view of FIG. 1 corresponds to the AA' portion of FIG. 2. FIG. 2 is a plan view of the inside of the housing base 103, which corresponds to a view from below in FIG. 1 and a view from above in FIG. 3.

[0017] As shown in FIG. 1, an electronic control device 101 of this embodiment has a circuit board 102 on which electronic components 201 are mounted, and a housing that houses the circuit board 102.

[0018] The housing is made of metal and has conductivity, and is composed of a housing base 103 and a housing cover 104. The circuit board 102 is covered from above and below by the housing base 103 and the housing cover 104.

[0019] An electronic component 201, which is both a heat source and a noise source, is mounted on the circuit board 102. The electronic component is, for example, an LSI or an IC. Note that, although other electronic components 201 are mounted on the circuit board 102 in addition to the electronic component 201 shown in FIG. 1 , they are not shown in the figure.

[0020] The circuit board 102 has a wiring pattern (not shown). This wiring pattern includes a signal wiring routing pattern and a GND pattern (ground pattern) that serves as a reference potential. The GND pattern may include a pattern that is DC-isolated via a capacitor or the like.

[0021] An external connector 204 is mounted on an end of the circuit board 102. A plurality of external connectors 204 of different shapes may be mounted. A portion of the external connector 204 is exposed to the outside of the housing through a housing opening 306 for a connector provided in the housing base 103 as shown in FIG.

[0022] The circuit board 102 is fixed to the housing base 103 by screws 105. The housing cover 104 is also fixed to the housing base 103 by screws 105. To this end, the housing base 103 has, as shown in Fig. 3, board fixing screw bosses 310 each having a board fixing screw hole 305 into which the screw 105 for fixing the circuit board 102 is inserted, and cover fixing screw bosses 311 each having a housing cover fixing screw hole 304 into which the screw 105 for fixing the housing cover 104 is inserted.

[0023] 1, the housing base 103 of this embodiment has a conductive first convex portion (heat dissipation convex portion 301) and a second convex portion (noise guiding convex portion 302) that are convex toward the circuit board 102. In this embodiment, the heat dissipation convex portion 301 and the noise guiding convex portion 302 are formed integrally with the housing base 103, but this is not limiting.

[0024] The heat dissipation convex portion 301, which is the first convex portion, is connected to the electronic component 201. This allows heat to be dissipated from the electronic component 201 to the housing base 103 via the heat dissipation convex portion 301. It is desirable that thermal grease 202 be inserted between the heat dissipation convex portion 301 and the electronic component 201.

[0025] As shown in FIGS. 1 , 2 , and 3 , the noise guide protrusion 302, which is the second protrusion, has a first connection portion connected to the outer peripheral surface of the heat dissipation protrusion 301 and a second connection portion (GND pattern connection portion 303) connected to the GND pattern of the circuit board 102 directly or via a connecting member. FIG. 1 shows an example in which an EMI gasket 203 is used as the connecting member. The EMI gasket 203 is a resilient conductive member. Note that a conductive metal member such as a screw may be used as the connecting member instead of the EMI gasket 203. Furthermore, to avoid the generation of an unintended DC current path due to electrical continuity between the housing base 103 and the GND pattern of the circuit board 102, the GND pattern to which the EMI gasket 203 is connected may be a pattern that is DC-isolated via a capacitor from the GND pattern to which the circuit on the circuit board 102 is connected.

[0026] 1, 2, and 3, the noise guiding protrusions 302 extend outward from the corners of the heat dissipation protrusions 301 and are connected to the GND pattern of the circuit board 102 at the GND pattern connection portions 303. By extending outward from the corners of the heat dissipation protrusions 301, the noise guiding protrusions 302 have a portion that extends in a direction away from the electronic component 201, starting from the corner of the electronic component 201 to which the heat dissipation protrusions 301 are connected.

[0027] The noise guide convex portion 302 is shaped so that the convex surface of the noise guide convex portion 302 is as close to the circuit board 102 as or closer to the convex surface of the heat dissipation convex portion 301 between the electronic component 201 and the GND pattern connection portion 303.

[0028] Generally, noise currents transmitted from electronic component 201 to housing base 103 via thermal grease 202 must return to electronic component 201 on circuit board 102 through some route according to Kirchhoff's current law. However, the wider the noise current spreads before returning, the more electromagnetic radiation it will radiate into space. In this embodiment, noise guide protrusion 302 is formed close to circuit board 102 and is connected to the GND pattern of circuit board 102 at GND pattern connection portion 303 beyond. This reduces the current loop 400. As a result, the impedance of current loop 400 as seen from electronic component 201 is reduced, and noise currents are concentrated along this path, preventing them from spreading over a wide area. This suppresses unwanted electromagnetic radiation. At the same time, the reciprocity theorem also reduces the impact of external noise on electronic component 201.

[0029] Furthermore, since the EMI gasket 203 for connecting to the GND pattern can be positioned away from the electronic component 201, it does not interfere with the routing of signal wiring connected to the electronic component 201 or the placement of components around the electronic component 201, thereby avoiding an increase in the number of board layers and size of the circuit board 102 and achieving cost reduction. Furthermore, since the shielding structure can be configured near the noise source, unnecessary electromagnetic radiation can be efficiently suppressed with a small number of EMI gaskets 203. Furthermore, since the signal wiring and peripheral components connected to the electronic component 201 are often placed around the sides of the electronic component 201, extending the noise guiding protrusions 302 obliquely from the corners of the electronic component 201 can further prevent the placement of the signal wiring and peripheral components from being affected.

[0030] In this embodiment, four noise guide protrusions 302 and EMI gaskets 203 are arranged for one electronic component 201, but the number may be increased or decreased as necessary.

[0031] Furthermore, in this embodiment, an example has been described in which the electronic component 201 is mounted on the housing base 103 side, but this is not limited to this. If the electronic component 201 is mounted on the housing cover 104 side, the housing cover 104 may be configured to have a heat dissipation convex portion 301 and a noise guide convex portion 302.

[0032] The second and subsequent examples are modifications of the first example, and the following description will focus on the differences from the first example. Other than that, the second example is the same as the first example, and therefore, redundant description will be omitted.

[0033] 5 is a plan view of a housing base of an electronic control device according to a second embodiment of the present invention, and corresponds to FIG.

[0034] This embodiment is an embodiment in which the noise guide protrusion 302 has a bent portion whose extension direction changes when viewed in a plane, and an embodiment in which the noise guide protrusion 302 is extended from the side of the electronic component 201 rather than from a corner of the electronic component 201.

[0035] In this embodiment, the noise guide protrusions 302 are not drawn out obliquely from the four corners of the electronic component 201, but are drawn out from the center of the side at a right angle to the side, drawn out from the end of the side at a right angle to the side, or drawn out obliquely but bent in a direction perpendicular to the side.

[0036] When it is difficult to pull out the electronic component 201 obliquely from the four corners as in Example 1 due to the positional relationship with the end of the circuit board 102, the screw 105, and the wiring pattern on the circuit board 102, the unwanted radiation reduction effect can be obtained by adopting the configuration of this example.

[0037] 6 is a cross-sectional view of an electronic control device according to a third embodiment of the present invention, which corresponds to FIG.

[0038] In this embodiment, the noise guide protrusion 302 has a notch 307 at a position where it overlaps with a component (for example, a surface-mounted component 205) mounted on the circuit board 102.

[0039] In this embodiment, when surface-mounted components 205 are arranged directly below noise guiding protrusions 302, notches 307 are provided in noise guiding protrusions 302 to avoid interference, thereby avoiding obstruction to component arrangement on circuit board 102. Note that by shaping notches 307 so that they are as close to circuit board 102 as or closer to the convex surface of heat dissipation protrusions 301, current loop 400 can be made smaller, as in FIG. 1 .

[0040] 7 is a plan view of a housing base of an electronic control device according to a fourth embodiment of the present invention, and corresponds to FIG.

[0041] This embodiment has a plurality of heat dissipation protrusions 301, and the noise guide protrusions 302 connected to one of the heat dissipation protrusions 301 and the noise guide protrusions 302 connected to the other heat dissipation protrusions 301 have a common GND pattern connection portion 303.

[0042] According to this embodiment, the GND pattern connection portion 303 can be shared, so that unnecessary radiation can be reduced with a small number of EMI gaskets 203 .

[0043] 8 is a cross-sectional view of an electronic control device according to a fifth embodiment of the present invention, and corresponds to FIG.

[0044] In this embodiment, a circuit board 102 has electronic components 201 mounted on both sides thereof, and the housing has a housing base 103 (first housing) facing one main surface of the circuit board 102 and having heat dissipation protrusions 301 and noise guiding protrusions 302, and a housing cover 104 (second housing) facing the other main surface of the circuit board 102 and having heat dissipation protrusions 301 and noise guiding protrusions 302.

[0045] This embodiment can also accommodate cases where electronic components 201, which are noise sources, are arranged on both sides of circuit board 102. Note that Fig. 8 shows an example in which housing cover 104 is manufactured by pressing a plate-like member, and therefore heat dissipation protrusions 301 and noise guiding protrusions 302 have hollow structures. Therefore, heat dissipation protrusions 301 appear to be recessed portions compared to noise guiding protrusions 302, but are convex portions when viewed from other parts of housing cover 104.

[0046] 9 is a plan view of a housing base of an electronic control device according to a sixth embodiment of the present invention, and corresponds to FIG.

[0047] In this embodiment, the width of the noise guide convex portion 302 narrows from the connection portion (first connection portion) with the heat dissipation convex portion 301 toward the GND pattern connection portion 303 (second connection portion).

[0048] In this embodiment, the noise guiding protrusions 302 have a tapered shape that is wider near the heat dissipation protrusions 301 and narrows toward the GND pattern connection portion 303. In this case, the noise guiding protrusions 302 may be connected to each other near the heat dissipation protrusions 301, as in the lower noise guiding protrusions 302 in Figure 9.

[0049] According to this embodiment, it is possible to more efficiently improve the shielding effect by making the noise guiding protrusion 302 wider on the side of the electronic component 201, which is the noise source, and narrowing it so that it is guided to the side of the GND pattern connection portion 303. This results in the suppression of unnecessary electromagnetic radiation and the reduction of the EMI gasket 203.

[0050] FIG. 10 is a perspective view of a noise guide structure of an electronic control unit according to a seventh embodiment.

[0051] In this embodiment, the noise guide protrusion 302 is thinner on the side closer to the circuit board 102 than on the side farther from the circuit board 102 .

[0052] According to this embodiment, the cross section of the noise guiding protrusion 302 has a tapered tip, which makes it less likely to interfere with components on the circuit board 102 .

[0053] 11 is a cross-sectional view of an electronic control device according to an eighth embodiment of the present invention, and corresponds to FIG.

[0054] In this embodiment, the GND pattern connection portion 303 (second connection portion) is a protrusion 308 formed on the surface of the noise guide convex portion 302, and this protrusion 308 is connected to the GND pattern of the circuit board 102 directly or via a connection member made of a dielectric 206.

[0055] In this embodiment, for example, a resist material or a fixing adhesive on the circuit board 102 can be used as the dielectric 206. When the dielectric 206 is used, capacitive coupling via the dielectric 206 provides an effect equivalent to that of electrical continuity at high frequencies.

[0056] According to this embodiment, the number of conductive connecting members such as the EMI gasket 203 and screws can be reduced, which is expected to result in cost reduction.

[0057] 12 is a plan view of a housing base of an electronic control device according to a ninth embodiment of the present invention, and corresponds to FIG.

[0058] In this embodiment, the noise guide protrusion 302 has a wall-like portion that is positioned so as to block at least one side of the heat dissipation protrusion 301 when viewed in the direction of the heat dissipation protrusion 301 from a position away from the heat dissipation protrusion 301.

[0059] In this embodiment, the noise guiding protrusion 302 is arranged like a wall so as to block at least a part of the direction of the heat dissipation protrusion 301, and is connected to the GND pattern connection part 303 at or along the way. The noise guiding protrusion 302 may have a branched part or a bent part.

[0060] According to this embodiment, the area shielded by the noise guide protrusions 302 can be expanded, thereby effectively suppressing unwanted electromagnetic radiation, and measures can be taken with a smaller number of EMI gaskets 203, which has the advantage of reducing costs.

[0061] Fig. 13 is a plan view of a housing base of the electronic control device of Example 10. Fig. 14 is a cross-sectional view of the electronic control device of Example 10. Fig. 13 is a view corresponding to Fig. 2, and Fig. 14 is a view corresponding to Fig. 1.

[0062] In this embodiment, noise guiding protrusions 302 are connected to screws 105 that secure circuit board 102, or to a structure that connects housing base 103 and circuit board 102 (gasket connection portions 309 around the connector and EMI gasket 203). In this embodiment, noise guiding protrusions 302 are connected to board fixing screw bosses 310, thereby connecting to screws 105 that secure circuit board 102. This allows screws 105 to be used in place of EMI gasket 203.

[0063] In this embodiment, the housing base 103 has a gasket connection portion 309 around the connector, which is a protrusion that surrounds the periphery of the external connector 204, and the gasket connection portion 309 around the connector is connected to the GND pattern of the circuit board 102 directly or via a connecting member such as an EMI gasket 203 or a screw. This makes it possible to shield noise from the external connector 204. Furthermore, the noise guide protrusions 302 are connected to the gasket connection portion 309 around the connector. This allows the EMI gasket 203 used to connect the gasket connection portion 309 around the connector to be shared with the EMI gasket 203 used to connect the GND pattern connection portion 303, so that fewer EMI gaskets 203 are required for the entire device.

[0064] 15 is a cross-sectional view of an electronic control device according to an eleventh embodiment of the present invention, and corresponds to FIG.

[0065] In this embodiment, the noise guide protrusion 302 is formed of a member (a noise guide protrusion member 312 ) separate from the housing base 103 .

[0066] In this embodiment, the noise guide is formed by a noise guide protrusion member 312 formed by bending a plate-like member, instead of the noise guide protrusion 302 formed integrally with the housing base 103. Not forming the noise guide from an integral member has the advantage that the position of the protrusion can be easily changed in response to changes in the design of the circuit board 102, etc.

[0067] In this embodiment, the noise guide protrusion member 312 is formed by bending a plate-like member, but it may be formed by a member other than a plate-like member.

[0068] 16 is a cross-sectional view of an electronic control device according to a twelfth embodiment of the present invention, which corresponds to FIG.

[0069] This embodiment has a plurality of circuit boards 102 , and at least one of the circuit boards 102 is connected to the noise guide protrusion 302 .

[0070] In this embodiment, the electronic control device 101 has a plurality of circuit boards 102, each of which is mounted with an electronic component 201. The circuit boards 102 are connected to one another by board-to-board connectors 207. The housing base 103 has water channels 313 for water cooling, and dissipates heat from the electronic components 201 using heat dissipation protrusions 301 and thermal grease 202. The housing base 103 has noise guiding protrusions 302 connected to each heat dissipation protrusion 301, and the GND pattern connection portions 303 of the noise guiding protrusions 302 are connected to the GND pattern of the circuit board 102 via the EMI gasket 203.

[0071] According to this embodiment, in order to improve the performance of the electronic control device 101, it is possible to accommodate a configuration having multiple circuit boards 102. Note that the cooling method may not be water cooling, but may be forced air cooling or natural air cooling. Furthermore, the number of circuit boards 102 may be further increased.

[0072] Although the embodiments of the present invention have been described above, the present invention is not limited to the configurations described in the embodiments, and various modifications are possible within the scope of the technical concept of the present invention. Furthermore, some or all of the configurations described in each embodiment may be combined and applied. For example, the embodiments may be combined and applied, such as applying the first embodiment in combination with the second and third embodiments.

[0073] 101: Electronic control device 102: Circuit board 103: Housing base 104: Housing cover 105: Screw 201: Electronic component 202: Thermal grease 203: EMI gasket (connecting member) 204: External connection connector 205: Surface-mounted component 206: Dielectric (connecting member) 207: Board-to-board connector 301: Heat dissipation convex portion (first convex portion) 302: Noise guiding convex portion (second convex portion) 303: GND pattern connection portion (second connection portion) 304: Housing cover fixing screw hole 305: Board fixing screw hole 306: Housing opening for connector 307: Notch 308: Protrusion (second connection portion) 309: Gasket connection portion around connector 310: Boss for board fixing screw 311: Boss for cover fixing screw 312: Member for noise guiding convex portion (second convex portion) 313: Waterway 400: Current loop

Claims

1. An electronic control device having a circuit board mounted with electronic components and a housing that houses the circuit board, wherein the circuit board has a GND pattern, the housing has a conductive first convex portion and a second convex portion that are convex toward the circuit board, the first convex portion is connected to the electronic component, the second convex portion has a first connection portion connected to the outer peripheral surface of the first convex portion and a second connection portion connected to the GND pattern directly or via a connection member, and the second convex portion is shaped so that, between the electronic component and the second connection portion, the convex surface of the second convex portion is as close to the circuit board as the convex surface of the first convex portion or closer to the circuit board than the convex surface of the first convex portion.

2. The electronic control device according to claim 1, wherein the connecting member is an EMI gasket or a screw.

3. An electronic control device according to claim 1, characterized in that the second protrusion has a portion extending from a corner portion of the electronic component to which the first protrusion is connected in a direction away from the electronic component.

4. The electronic control device according to claim 1, wherein the second convex portion has a bent portion whose extension direction changes when viewed in a plane.

5. An electronic control device according to claim 1, wherein the second protrusion has a notch at a position that overlaps with a component mounted on the circuit board.

6. An electronic control device according to claim 1, characterized in that it has a plurality of the first convex portions, and the second convex portion connected to one of the first convex portions and the second convex portion connected to the other of the first convex portions have a common second connection portion.

7. An electronic control device according to claim 1, characterized in that the circuit board has the electronic components mounted on both sides, and the housing has a first housing facing one main surface of the circuit board and having the first convex portion and the second convex portion, and a second housing facing the other main surface of the circuit board and having the first convex portion and the second convex portion.

8. The electronic control device according to claim 1, wherein the second protrusion has a width that narrows from the first connection portion toward the second connection portion.

9. An electronic control device according to claim 1, wherein the second protrusion is thinner on a side closer to the circuit board than on a side farther from the circuit board.

10. An electronic control device according to claim 1, characterized in that the second connection portion is a protrusion formed on the surface of the second convex portion, and the second connection portion is connected to the GND pattern directly or via the connection member made of a dielectric.

11. An electronic control device as claimed in claim 1, characterized in that the second convex portion has a wall-like portion arranged in a position blocking at least one side of the first convex portion when viewed in the direction of the first convex portion from a position away from the first convex portion.

12. An electronic control device according to claim 1, characterized in that the second protrusion is connected to a screw for fixing the circuit board or to a structure for connecting the housing and the circuit board.

13. The electronic control device according to claim 1, wherein the second protrusion is formed of a separate member from the housing.

14. An electronic control device according to claim 1, comprising a plurality of said circuit boards, at least one of said circuit boards being connected to said second protrusion.

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