JP2012005244A - On-vehicle electronic control unit device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To protect electronic components airtightly housed in a resin case from being subject to the influence of external noise.SOLUTION: A storage unit 23, a microcomputer 24, and an acceleration sensor 22, which are electronic components airtightly housed in a resin case 11, are enclosed by an earth layer 51a formed on an entire inner layer of a multilayer substrate 51 and a metal housing cover 13 placed on the back side of the multilayer substrate 51 so as to be shielded from an exterior portion to avoid the influence of external noise.

Description

  The present invention relates to an in-vehicle electronic control unit device used for an occupant protection device such as an air bag for protecting an occupant in the event of a vehicle collision, and more particularly, to an electronic device on a printed circuit board that is disposed in a housing of the electronic control unit in the event of a vehicle collision. The present invention relates to an on-vehicle electronic control unit device that can protect components from external noise.

  Conventionally, as this type of vehicle-mounted electronic control unit device, there is a housing for electronic devices described in Patent Document 1. As shown in FIG. 1, the casing 100 is a device of an electronic control unit of a vehicle, and includes a metal base 30 that houses a circuit board 10 on which an electronic component 12 is mounted, and a case 20. It is attached to a body to be attached such as a vehicle. In such a configuration, since the electronic component 12 is shielded by the metal casing formed by the case 20 and the base 30, the electronic component 12 can be protected from external noise.

JP 2008-41718 A

  By the way, in recent years, the case is made of resin in order to reduce the size and weight of the on-vehicle electronic control unit device as a whole. However, in the above Patent Document 1, when the case 20 is made of resin, the electronic component 12 mounted on the circuit board 10 in the case is affected by external noise, and for example, a CPU (one of the electronic components 12 ( There arises a problem that the central processing unit) malfunctions.

  The present invention has been made in view of such circumstances, and an on-vehicle electronic control unit device capable of protecting an electronic component housed in a sealed state in a resin case so as not to be affected by external noise. The purpose is to provide.

  In order to achieve the above object, the invention according to claim 1 is a box-shaped resin case having a lower opening, and is housed in the case from the opening of the case so that an electronic component is mounted. A multi-layered substrate and a metal housing cover configured to cover the opening of the housing case, the substrate is housed in the housing case, and the substrate is covered with the housing case by the housing cover. In the on-vehicle electronic control unit device that is sandwiched between and fixed in a state in which the opening is closed, the multilayer substrate has a ground layer formed on the entire surface or the entire inner surface facing the housing case side, and the housing The electronic component is mounted on the back surface facing the cover side.

  According to this configuration, the electronic component housed in the resin case in a hermetically sealed state is surrounded by the ground layer formed on the entire surface of the multilayer substrate or the entire inner layer and the metal housing cover, and is shielded from the outside. Thus, the electronic component can be protected from being affected by external noise.

  The invention according to claim 2 is characterized in that an acceleration sensor for measuring the acceleration of the vehicle is mounted on the multilayer board, and the electronic component is a microcomputer that determines a collision of the vehicle from information of the acceleration sensor. .

  According to this configuration, only the electronic components and sensor components that are affected by external noise are mounted on the back surface of the multilayer substrate, so that the front and back surfaces of the multilayer substrate can be used effectively.

It is a perspective view which shows the decomposition | disassembly structure of the conventional housing for electronic devices. It is a perspective view which shows the structure which saw through the external appearance and one part of the inside of the vehicle-mounted electronic control unit apparatus which concerns on embodiment of this invention. It is a perspective view which shows the structure which decomposed | disassembled the vehicle-mounted electronic control unit apparatus shown in FIG. It is a block diagram which shows the structure of ECU circuit components mounted in the control circuit board of the vehicle-mounted electronic control unit apparatus which concerns on this embodiment. It is A1-A2 sectional drawing of the vehicle-mounted electronic control unit apparatus shown in FIG.

  Embodiments of the present invention will be described below with reference to the drawings. However, parts corresponding to each other in all the drawings in this specification are denoted by the same reference numerals, and description of the overlapping parts will be omitted as appropriate.

  FIG. 2 is a perspective view showing the configuration of the exterior and part of the interior of the in-vehicle electronic control unit device according to the embodiment of the present invention. FIG. 3 is a perspective view showing an exploded configuration of the in-vehicle electronic control unit device shown in FIG.

  As shown in FIG. 3, an in-vehicle electronic control unit device (ECU) 50 shown in FIG. 2 is a box-shaped resin case 11 that is open at the bottom, and is inserted into the case from the opening of the case 11. It is composed of a multilayer substrate 51 that is fixed and integrally combined with a plurality of plate-like wiring layers, and a housing cover 13 that is a metal plate such as iron that is fixed to the opening of the housing case 11 and covers the opening. .

  In the casing case 11, columnar members 11a are fixed to the four corners of the case, a recess is formed on the opening side of the columnar member 11a, and an insert nut 11b that is screwed and fixed to the recess is fitted and fixed. ing. Further, on one side surface of the housing case 11, a rectangular cutout portion 11 c that fits the box-shaped connector 16 mounted on the multilayer substrate 51 is formed.

  The multilayer substrate 51 is provided with a threaded hole 12a that penetrates through the four corners to fix the multilayer substrate 51 between the housing case 11 and the housing cover 13. Each screw hole 12 a corresponds to the position of each insert nut 11 b of the housing case 11.

  Further, an ECU circuit 21 shown in FIG. 4 is configured on the upper surface and the rear surface of the multilayer substrate 51, which includes an acceleration sensor 22 that detects vehicle acceleration, a storage device 23 that stores data, and an external IF. (Interface) 25, a microcomputer 24 to which the acceleration sensor 22, the storage device 23, and the external IF 25 are connected, and an airbag driving circuit 26 that is controlled by the microcomputer 24 and drives an airbag (not shown). Has been. Each external IF (interface) 25 a to 25 n is combined with a connector 16. When the microcomputer 24 determines that the vehicle has collided according to an acceleration sensor (not shown) connected to the external IFs 25a to 25n or an acceleration detected by the acceleration sensor 22, the microcomputer 24 performs control to open an airbag (not shown). At the same time, the storage device 23 performs control to store vehicle information including vehicle speeds before and after the vehicle collision.

  The housing cover 13 is formed with screw holes 13a for screwing screws 15 into positions corresponding to the screw holes 12a of the multilayer substrate 51, and further protruding in a convex shape on two sides (or edges) facing each other. Two mounting portions 13b1, 13b2, and 13b3 are provided. In this, two attachment portions 13b1 and 13b3 are provided on one side, and one attachment portion 13b2 is provided on the other side. These attachment portions 13b1 to 13b3 are for fixing the ECU 50 at predetermined positions of the vehicle.

  When the ECU 50 is configured by assembling the housing case 11, the multilayer substrate 51, and the housing cover 13, the multilayer substrate 51 is sandwiched between the housing case 11 and the housing cover 13, and the position of each insert nut 11 b of the housing case 11. In addition, the screw holes 12 a of the multilayer substrate 51 and the screw holes 13 c of the housing cover 13 are aligned, and screws 15 are screwed and fixed from below the housing cover 13. The ECU 50 thus formed is screwed to the vehicle via the attachment portions 13b1 to 13b3. In the fixed ECU 50, as shown in FIG. 2, the side opposite to the mounting side of the connector 16 is the vehicle front side, and the mounting side of the connector 16 is the vehicle rear side. Furthermore, it is assumed that the side on which the two attachment portions 13b1 and 13b3 are provided is the vehicle right side, the side on which the one attachment portion 13b2 is provided is the vehicle left side, and the housing case 11 is the upper side.

  The feature of the present embodiment in the ECU 50 configured as described above is that an earth layer 51a is provided on the entire inner surface of the multilayer substrate 51, as shown in FIG. Electronic parts such as the storage device 23 and the microcomputer 24 and sensor parts such as the acceleration sensor 22 are mounted on the back surface facing the housing cover 13 side, and these mounting parts are shielded between the multilayer substrate 51 and the housing cover 13 from the outside. It is in the point set as the structure accommodated in a state.

  In the ECU 10 according to this embodiment, the storage device 23, the microcomputer 24, and the acceleration sensor 22 that cause malfunction due to the influence of external noise include the ground layer 51 a formed on the entire inner surface of the multilayer substrate 51, and this Since it is surrounded by the metal housing cover 13 disposed on the back side of the multilayer substrate 51 and stored in a shielded state from the outside, it is not affected by external noise.

  Further, only the microcomputer 24 may be enclosed by the ground layer 51a and the housing cover 13 and housed in a shielded state from the outside. Further, all the electronic components constituting the ECU circuit 21 are connected to the ground layer. It may be surrounded by 51a and the housing cover 13 and housed outside and in a shielded state. Further, the earth layer 51a may be formed on the entire surface of the multilayer substrate 51 facing the housing case 11 side. With such a configuration, it is possible to protect the electronic component housed in the housing case 11 so as not to be affected by external noise.

DESCRIPTION OF SYMBOLS 11 Housing | casing case 11a Columnar member 11c Notch part 11b Insert nut 12a Screw hole 13 Housing cover 13b1, 13b2, 13b3 Mounting part 15 Screw 16 Connector 21 ECU circuit 22 Acceleration sensor 23 Memory | storage device 24 Microcomputer 25a-25n External IF (interface)
50 On-vehicle electronic control unit (ECU)
51 multilayer boards

Claims (2)

A box-shaped resin case with an opening at the bottom, a multilayer board that is housed in the housing case from the opening of the housing case and on which electronic components are mounted, and a metal that covers the opening of the housing case An in-vehicle housing that has a housing cover made of a material, houses the substrate in the housing case, holds the substrate between the housing case and the housing case, and fixes the opening in a closed state. In the electronic control unit device,
The in-vehicle electronic control unit, wherein the multilayer substrate has a ground layer formed on the entire front surface or inner layer surface facing the housing case side, and the electronic component is mounted on the back surface facing the housing cover side. apparatus.   The in-vehicle electronic device according to claim 1, wherein an acceleration sensor that measures vehicle acceleration is mounted on the multilayer board, and the electronic component is a microcomputer that determines vehicle collision from information of the acceleration sensor. Control unit device.

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