JP2023127765A - Electronic control device - Google Patents

Abstract

To provide an electronic control device with a high anti-electrostatic discharge property.SOLUTION: An electronic control device 100 comprises: a circuit board 3 that mounts an electronic component 1 and a connector 2; a case 4 that houses the circuit board 3, opening only on the side where the connector 2 is attached; and a resin part 11 filled in the case 4. The case 4 is a metal case that has a holding part 8 sandwiching and supporting the circuit board 3 inserted in the case 4. The circuit board 3 has a GND pad 6b connected with a GND pattern. The GND pad 6b is in contact with the holding part 8 of the case 4.SELECTED DRAWING: Figure 5

Description

The present invention relates to an electronic control device.

Electronic control devices installed in automobile engine compartments, motorcycles, etc. are installed in harsh environments where vibrations, high-pressure water, chemicals, etc. are present. For this reason, some vehicle-mounted electronic control devices employ a structure in which a resin material is filled between a circuit board and a housing, as disclosed in Patent Document 1, for example.

JP2012-89648A

In recent years, electronic control devices installed in automobiles, motorcycles, etc. have become more sophisticated, and as a result, demands for EMC (Electro Magnetic Compatibility) measures for electronic control devices have increased. As a countermeasure against EMC, a method of blocking electromagnetic noise may be considered by changing the case (housing) of the electronic control device from resin to metal. However, if a metal case is used, the static electricity applied to the case may also be applied to the electronic components, potentially damaging the electronic components.

An object of the present invention is to provide an electronic control device with high electrostatic discharge resistance (ESD resistance).

In order to solve the above problems, for example, the configurations described in the claims are adopted.
The present application includes multiple means for solving the above problems, but to name one, it is possible to open only the circuit board on which electronic components and connectors are mounted, and the side to which the connector is attached, and to accommodate the circuit board. This is an electronic control device that includes a case and a resin part filled inside the case. The case is a metal case that has a holding part that holds and supports a circuit board inserted into the case. The circuit board has a GND pattern and a GND pad connected to the GND pattern, and the GND pad is in contact with the holding part of the case.

According to the present invention, it is possible to provide an electronic control device with high resistance to electrostatic discharge.
Problems, configurations, and effects other than those described above will be made clear by the following description of the embodiments.

FIG. 1 is an exploded view showing the configuration of an electronic control device according to a first embodiment. FIG. 2 is a front view showing the structure of a circuit board included in the electronic control device according to the first embodiment. FIG. 2 is a perspective view illustrating the structure of a case included in the electronic control device according to the first embodiment. FIG. 2 is a perspective view showing the configuration of an electronic control device according to a second embodiment. FIG. 5 is a diagram illustrating a cross-sectional structure at the AA position of the electronic control device shown in FIG. 4. FIG. It is a figure explaining the cross-sectional structure of the electronic control device concerning a 3rd embodiment. FIG. 3 is a perspective view showing the configuration of an electronic control device according to a fourth embodiment. FIG. 8 is a diagram illustrating a cross-sectional structure at the BB position of the electronic control device shown in FIG. 7; FIG. 7 is a front view showing the structure of a circuit board included in an electronic control device according to a fifth embodiment.

Embodiments of the present invention will be described in detail below with reference to the drawings. In this specification and the drawings, elements having substantially the same functions or configurations are designated by the same reference numerals, and redundant description will be omitted.

(First embodiment)
FIG. 1 is an exploded view showing the configuration of an electronic control device according to the first embodiment. FIG. 2 is a front view showing the structure of a circuit board included in the electronic control device according to the first embodiment.
As shown in FIGS. 1 and 2, the electronic control device 100 includes an electronic component 1, a connector 2, a circuit board 3, a case 4, and a seal member 5. The electronic control device 100 is an in-vehicle electronic control device installed in an automobile, motorcycle, or the like. However, the electronic control device 100 can also be used for applications other than vehicle-mounted.

Connector 2 is mounted on circuit board 3. The connector 2 is mounted close to one side of the circuit board 3. In the following description, a portion of the circuit board 3 on which the connector 2 is mounted will be referred to as a connector mounting portion. The connector 2 electrically connects an electric circuit formed on the circuit board 3 to an external device (not shown). The connector 2 has a plurality of terminals 21 connected to the wiring pattern of the electric circuit, and an insulating housing 22 that supports these terminals 21. Each terminal 21 is made of a conductive material such as metal, and is connected to the circuit board 3 by soldering or the like. The housing 22 is made of an insulating material such as resin, and forms the main body of the connector 2 . The connector 2 is manufactured, for example, by insert molding. Further, the connector 2 is configured to be removably attached to a connector (not shown) in a male-female relationship.

The circuit board 3 is, for example, a rectangular board made of a printed wiring board or the like. The four corners of the circuit board 3 are formed into a rounded shape, that is, a round shape. In addition to the connector 2 described above, electronic components 1 are mounted on the circuit board 3. The electronic component 1 is, for example, a semiconductor component having a package structure in which a semiconductor chip such as a CPU with a high operating frequency mounted in an electronic control device for ADAS or AD is sealed with resin or the like. Note that a plurality of electronic components (not shown) other than the electronic component 1 are also mounted on the circuit board 3.

On the circuit board 3, a GND pattern 6a forming a GND (ground) wiring and a GND pad 6b connected to the GND pattern 6a are formed. The GND pattern 6a constitutes a part of the wiring pattern forming the above-mentioned electric circuit. Moreover, the GND pattern 6a is electrically connected to the ground of the vehicle through the GND terminal 21 among the plurality of terminals 21 that the connector 2 has. Note that in FIGS. 1 and 2, only a part of the GND pattern 6a is shown.

The GND pad 6b is arranged on the side opposite to the side on which the connector 2 is attached in the insertion direction of the circuit board 3 into the case 4 (hereinafter also referred to as "board insertion direction"). The side to which the connector 2 is attached is the side where the opening 40 of the case 4 is present, and the side opposite to the side to which the connector 2 is attached is the side where the wall 4e of the case 4 is present. GND pads 6b are arranged on both sides of circuit board 3. In this case, the circuit board 3 is constituted by a double-sided printed wiring board or the like. By arranging the GND pads 6b on both sides of the circuit board 3, when the pad forming portion of the circuit board 3 is supported by the clamping parts 8, the GND pads 6b and the clamping parts 8 can be brought into contact with each other more reliably. Further, the GND pads 6b are arranged on both sides in a direction perpendicular to the board insertion direction. Specifically, the GND pad 6b is arranged at the farthest corner of the circuit board 3 when viewed from the connector 2 side. Thereby, the degree of freedom in determining the layout of the wiring pattern of the circuit board 3 can be increased. The GND pad 6b is a pad formed by copper plating, for example. In this case, the GND pad 6b becomes an exposed portion of the copper foil. The thickness (plating thickness) of the GND pad 6b is preferably 20 μm or more and 150 μm or less from the viewpoint of suppressing conduction defects due to pad peeling or the like.

The case 4 is a metal case that houses the circuit board 3 in order to protect the circuit board 3 on which the electronic component 1 is mounted. If the metal case 4 is used, an effect of blocking electromagnetic noise can be obtained. The case 4 is formed into a rectangular parallelepiped shape with five walls 4a, 4b, 4c, 4d, and 4e forming a space for accommodating the circuit board 3. The case 4 is open only on the side where the connector 2 is attached in order to insert the circuit board 3 into the inside of the case 4. The opening 40 of the case 4 is formed at a position facing the wall 4e of the case 4. Further, the opening 40 of the case 4 is closed by the housing 22 of the connector 2 by inserting the circuit board 3 into the case 4 through the opening 40. The inside of the case 4 is filled with a resin part 11. The resin portion 11 is made of, for example, thermosetting resin. The resin part 11 is a part that seals a part of the electronic component 1, the circuit board 3, and the connector 2 housed in the case 4 with a resin material. The resin portion 11 contains a conductive filler.

The seal member 5 is a member that seals between the case 4 and the connector 2. The seal member 5 is formed in a rectangular ring shape to match the opening shape of the case 4. The sealing member 5 exhibits a sealing function by being sandwiched between the opening edge of the case 4 and the corresponding housing 22 of the connector 2.

FIG. 3 is a perspective view illustrating the structure of a case included in the electronic control device according to the first embodiment.
As shown in FIG. 3, the case 4 sandwiches and supports a board insertion guide 7 that guides the insertion of the circuit board 3, and the circuit board 3 that is guided by the board insertion guide 7 and inserted into the case 4. It has a holding part 8. The board insertion guide 7 and the holding part 8 are formed on the inner surfaces of two walls 4c and 4d located on both sides of the case 4. The board insertion guide 7 and the holding part 8 are integrally formed with the metal case 4. Therefore, both the board insertion guide 7 and the holding part 8 have electrical conductivity.

The board insertion guide 7 is composed of a pair of guide rails 7a and 7b. One end portion of the pair of guide rails 7a, 7b is widened into a tapered shape near the opening 40 of the case 4. This makes it easier to insert the circuit board 3 between the pair of guide rails 7a and 7b.

The holding portion 8 is arranged on the side opposite to the side on which the connector 2 is attached in the insertion direction of the circuit board 3 into the case 4 . That is, the holding part 8 is arranged on the same side as the GND pad 6b in the board insertion direction. The holding portion 8 is arranged inside the pair of guide rails 7a and 7b, and is arranged to protrude beyond the board insertion guide 7. The protrusion dimension of the holding part 8 is such that when the circuit board 3 is housed in the case 4, the part where the GND pad 6b is formed (hereinafter also referred to as "pad forming part") is sandwiched by the holding part 8. , are set in accordance with the position of the GND pad 6b of the circuit board 3.

The clamping portion 8 is composed of a pair of clamping pieces 8a and 8b. In the height direction of the case 4, the clamping piece 8a is arranged inside the guide rail 7a, and the clamping piece 8b is arranged inside the guide rail 7b. The inside of the guide rail 7a is the side facing the guide rail 7b, and the inside of the guide rail 7b is the side facing the guide rail 7a. Furthermore, the holding portion 8 has tapers 9a and 9b at an entrance portion for receiving the circuit board 3. The taper 9a is formed on the clamping piece 8a, and the taper 9b is formed on the clamping piece 8b. Since the holding part 8 has the tapers 9a and 9b, the circuit board 3 inserted into the case 4 along the board insertion guide 7 can be smoothly inserted into the holding part 8 (between the pair of holding pieces 8a and 8b). can be introduced into.

When assembling the electronic control device 100 according to the first embodiment, by inserting the circuit board 3 into the case 4 along the board insertion guide 7 of the case 4, the pad forming part of the circuit board 3 is inserted into the holding part 8. caught between. At this time, the GND pad 6b of the circuit board 3 comes into contact with the holding part 8. Therefore, when static electricity is applied to the case 4, this static electricity is transmitted through the holding part 8 of the case 4, the GND pattern 6a and the GND pad 6b of the circuit board 3, and the ground terminal 21 of the connector 2. , which is ultimately discharged to the vehicle's ground. Therefore, even if static electricity is applied to the case 4, the static electricity will not be applied to the electronic components 1 etc. on the circuit board 3. Therefore, damage to the electronic component 1 etc. can be prevented. As a result, it is possible to provide the electronic control device 100 with high resistance to electrostatic discharge.

Furthermore, in the electronic control device 100 according to the first embodiment, the GND pad 6b of the circuit board 3 and the holding part 8 that supports the pad forming part of the circuit board 3 are arranged on the opposite side from the connector mounting part. ing. As a result, the end of the circuit board 3 that is far from the seal member 5 is supported by the holding portion 8 . Therefore, the earthquake resistance of the electronic control device 100 can be improved.

Note that the board insertion guide 7 and the holding part 8 do not necessarily have to have an integral structure with the case 4, but in order to facilitate manufacturing of the electronic control device 100, it is preferable that they have an integral structure. Furthermore, at least a portion of the holding portion 8 that contacts (connects) with the GND pad 6b of the circuit board 3 has conductivity, and connects the GND pad 6b and the case 4 electrically via this conductive portion. It suffices if the configuration is such that it connects to. Further, the board insertion guide 7 does not necessarily need to be electrically conductive. The above points also apply to other embodiments described later.

(Second embodiment)
FIG. 4 is a perspective view showing the configuration of an electronic control device according to the second embodiment. FIG. 5 is a diagram illustrating a cross-sectional structure of the electronic control device shown in FIG. 4 at the AA position.
The electronic control device 100 according to the second embodiment is characterized by the dimensional relationship between the board insertion guide 7 formed in the case 4 and the holding part 8 that supports the circuit board 3. Specifically, when the guide width at which the board insertion guide 7 guides the insertion of the circuit board 3 is t1 (mm), and the clamping width at which the clamping part 8 supports the circuit board 3 by sandwiching it is t2 (mm), The clamping width t2 is narrower than the guide width t1. The clamping width t2 is defined by the dimension between the pair of guide rails 7a, 7b, and the guide width t1 is defined by the dimension between the pair of clamping pieces 8a, 8b.

When the clamping width t2 is made narrower than the guide width t1 as described above, the position of the circuit board 3 is regulated by the pair of guide rails 7a, 7b, and the pad forming portion of the circuit board 3 is held by the pair of clamping pieces 8a, 7b. It can be led between 8b and 8b. Therefore, the pad forming portion of the circuit board 3 can be smoothly inserted into the holding portion 8. Further, by narrowing the clamping width t2, the GND pad 6b of the circuit board 3 can be brought into reliable contact with the clamping portion 8. Thereby, when static electricity is applied to the case 4, the static electricity easily flows to the GND pad 6b. Therefore, the ESD resistance reliability of the electronic control device 100 can be improved.

(Third embodiment)
FIG. 6 is a diagram illustrating a cross-sectional structure of an electronic control device according to a third embodiment.
The electronic control device 100 according to the third embodiment is characterized by the shape of the holding portion 8 in the case 4 and the shape of the circuit board 3. Specifically, the holding portion 8 is formed with tapers 10a and 10b in addition to the tapers 9a and 9b described above. Tapers 9a and 9b are formed at the entrance portion for receiving the circuit board 3, and tapers 10a and 10b are formed at the end portions opposite to the entrance portion.

On the other hand, the end portion 3a of the circuit board 3 is formed into a wedge shape so as to follow the shape of the tapers 10a and 10b described above. The end portion 3a of the circuit board 3 is located on the opposite side from the connector mounting portion in the board insertion direction. The wedge-shaped end portion 3a of the circuit board 3 is abutted against the tapers 10a and 10b of the holding portion 8. This makes it easier to insert the pad forming portion of the circuit board 3 into the holding portion 8 (between the pair of holding pieces 8a and 8b). Further, by abutting the end portion 3a of the circuit board 3 with the tapers 10a, 10b of the holding portion 8, the circuit board 3 can be positioned with high accuracy. Therefore, the GND pad 6b of the circuit board 3 can be brought into contact with the holding part 8 more reliably.

Furthermore, even if the thickness of the pad forming portion of the circuit board 3 is set larger than the clamping width t2 of the clamping part 8 (see FIG. 5), the wedge shape of the edge 3a of the circuit board 3 can be used to The pad forming portion of the substrate 3 can be press-fitted into the holding portion 8 . By adopting a structure in which the pad forming portion of the circuit board 3 is press-fitted into the holding portion 8, it is possible to reliably bring the GND pad 6b of the circuit board 3 into contact with the holding portion 8, and to stably maintain this contact state. can. Therefore, the ESD resistance reliability of the electronic control device 100 can be further improved.

(Fourth embodiment)
FIG. 7 is a perspective view showing the configuration of an electronic control device according to the fourth embodiment. FIG. 8 is a diagram illustrating the cross-sectional structure of the electronic control device shown in FIG. 7 at the BB position.
As shown in FIGS. 7 and 8, the case 4 of the electronic control device 100 has a caulking portion 12 formed therein. Then, the pad forming part of the circuit board 3 inserted between the pair of clamping pieces 8a and 8b is fixed to the clamping part 8 by crimping the clamping part 8 from the outside of the case 4 to form a crimped part 12. It is crimped and fixed. Thereby, even if vibration or the like is applied to the electronic control device 100, the GND pad 6b and the holding portion 8 can be kept in constant contact with each other. Therefore, the ESD resistance reliability of the electronic control device 100 can be further improved.

(Fifth embodiment)
FIG. 9 is a front view showing the structure of a circuit board included in the electronic control device according to the fifth embodiment.
In the fifth embodiment shown in FIG. 9, the GND pad 6b of the circuit board 3 is arranged near the position where the connector 2 is attached in the insertion direction of the circuit board 3 into the case 4, and the case 4 A holding part 8 (not shown) is also arranged near the connector mounting part. By arranging the GND pad 6b and the holding portion 8 near the connector 2 in this manner, the distance from the GND pad 6b to the GND terminal 21 is shortened. Therefore, when static electricity applied to the case 4 flows through the GND pattern 6a, the influence of noise on peripheral components can be suppressed.

Note that the present invention is not limited to the embodiments described above, and includes various modifications. For example, in the embodiments described above, the content of the present invention is explained in detail to make it easier to understand, but the present invention is not necessarily limited to having all the configurations described in the embodiments described above. Further, it is possible to replace a part of the configuration of one embodiment with the configuration of another embodiment. Furthermore, it is also possible to add the configuration of another embodiment to the configuration of one embodiment. It is also possible to delete some of the configurations of each embodiment, add other configurations, or replace them with other configurations.

DESCRIPTION OF SYMBOLS 1...Electronic component, 2...Connector, 3...Circuit board, 3a...End part, 4...Case, 5...Sealing member, 6a...GND pattern, 6b...GND pad, 7...Board insertion guide, 8...Holding part, 9a , 9b, 10a, 10b...Taper, 11...Resin part, 12...Clinching part, 40...Opening, 100...Electronic control device

Claims (12)

A circuit board equipped with electronic components and connectors,
a case that is open only on the side where the connector is attached and houses the circuit board;
a resin part filled inside the case;
An electronic control device comprising:
The case is a metal case having a holding part that holds and supports the circuit board inserted into the case,
The circuit board has a GND pattern and a GND pad connected to the GND pattern,
The GND pad is in contact with the holding part of the case. Electronic control device. The electronic control device according to claim 1, wherein the holding portion and the GND pad are arranged on a side opposite to a side to which the connector is attached in a direction in which the circuit board is inserted into the case. The electronic control device according to claim 1, wherein the holding portion and the GND pad are arranged near a position where the connector is attached in a direction in which the circuit board is inserted into the case. The case has a board insertion guide that guides insertion of the circuit board,
The electronic control device according to claim 1 or 2, wherein a holding width at which the holding portions hold and support the circuit board is narrower than a guide width at which the board insertion guide guides insertion of the circuit board. 5. The electronic control device according to claim 1, wherein an end of the circuit board opposite to the connector mounting portion is formed into a wedge shape. The electronic control device according to claim 1, wherein the holding portion has a taper at an entrance portion for receiving the circuit board and/or at an end portion opposite to the entrance portion. The electronic control device according to any one of claims 1 to 6, wherein a portion of the circuit board where the GND pad is formed is press-fitted into the holding portion. The electronic control device according to any one of claims 1 to 6, wherein a portion of the circuit board on which the GND pad is formed is crimped and fixed to the holding portion. The electronic control device according to any one of claims 1 to 8, wherein the GND pad is arranged at a corner of the circuit board. The electronic control device according to any one of claims 1 to 9, wherein the GND pads are arranged on both sides of the circuit board. The electronic control device according to any one of claims 1 to 10, wherein the resin portion contains a conductive filler. The electronic control device according to any one of claims 1 to 11, wherein the GND pad has a thickness of 20 μm or more and 150 μm or less.

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