JP2019165041A - Electronic device and assembly method of electronic device - Google Patents

Abstract

To provide an electronic device capable of simplifying the assembly process while improving the seismic performance of the mounting board attached to the case.SOLUTION: An electronic device 10 comprises a mounting board 2, and a case 1 accommodating the mounting board 2. The mounting board 2 is fastened to the case 1 with at least one screw 3, and the corners of the mounting board 2, which are not fastened, are sandwiched between the notches of the ribs 1a to 1c provided in the case 1.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an electronic device and a method for assembling the electronic device.

  2. Description of the Related Art Conventionally, in a mounting substrate fixing structure in an electronic device, it is common to fix a mounting substrate by fastening the mounting substrate with a screw in a screw hole provided in a fixing case.

  Incidentally, in recent years, there has been a demand for downsizing of electronic devices, and along with this, the substrate size tends to be reduced. In order to secure a mounting area within a limited board size, the mounting board should be fastened to the case with two screws diagonally to the mounting board or one screw in the center of the mounting board. There is. However, in such a fixing structure, when external vibration is applied to the electronic device, a portion that is not fastened by the screw is greatly deformed. The mounting component is stressed by the deformation of the mounting substrate, and the bonding reliability of the mounting component is reduced.

  In Patent Document 1, in a case of a vehicle-mounted control device mounted on a vehicle, a boss for fixing the substrate is provided at the bottom of the case main body that accommodates the substrate, and a peripheral portion of the substrate is provided on the inner wall of the case main body. It is described that the vibration of the substrate is limited by the stepped portion by providing the stepped portion supporting the substrate.

  Further, in Patent Document 2, in order to increase the component mounting density, the substrate has a through hole that is inserted by a substrate fixing pin protruding from the substrate mounting surface of the resin case. A structure in which pins are soldered is described.

  Further, in Patent Document 3, in order to improve vibration resistance, one or more protrusions are adhered and installed on one side of the mounting substrate, and the peripheral portion of the mounting substrate is fastened to the peripheral portion of the base member. It is described that when fixing, a part of the protrusion is brought into contact with the base member, and the mounting substrate is bent in a convex shape by the protrusion.

JP-A-11-284374 JP 2007-149747 A JP 2009-111171 A

  However, in the structure described in Patent Document 1, since only one side of the mounting substrate is supported by the stepped portion of the housing, the mounting substrate on the side opposite to the stepped portion of the housing is against vibration loads. There is a problem that deformation cannot be suppressed.

  Further, in the structure described in Patent Document 2, since the fixing pin is fixed by soldering in a state of being inserted into the through hole of the mounting substrate, it takes time for drilling the mounting substrate, and the component of the fixing pin There is a problem that the number of points and the soldering process increase.

  Further, in the structure described in Patent Document 3, the mounting substrate is bent in a convex shape by the protrusions, so that the mounting area is reduced due to the influence of the protrusions. Moreover, since stress is always applied to the mounting component due to the warping of the mounting substrate, there is a problem that the bonding reliability of the mounting component is lowered.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide an electronic device that can improve the earthquake resistance of a mounting board attached to a case and can simplify an assembly process. .

An electronic device according to one aspect of the present invention is
A mounting board;
A case for housing the mounting substrate;
With
The mounting board is fastened to the case by at least one screw,
The corners of the mounting substrate that are not fastened are sandwiched between rib notches provided in the case.

  ADVANTAGE OF THE INVENTION According to this invention, while improving the earthquake resistance performance of the mounting substrate attached to a case in an electronic device, the simplification of an assembly process can be enabled.

FIG. 3 is a plan view of the electronic apparatus according to the first embodiment. The figure which shows the cross section cut | disconnected along the AA of the electronic device shown in FIG. The figure which shows the cross section cut | disconnected along the BB line of the electronic device shown in FIG. The perspective view which looked at the case of the electronic device which concerns on 1st Embodiment from the opposite side to the 1st rib. The perspective view which looked at the case of the electronic device which concerns on 1st Embodiment from the opposite side to the 2nd rib. The perspective view which looked at the case of the electronic device which concerns on 1st Embodiment from the opposite side to the 3rd rib. The graph which shows the result of having verified the characteristic of the vibration amplitude with respect to the frequency of an external vibration by simulation. The figure for demonstrating the assembly method of the electronic device which concerns on 1st Embodiment. The figure for demonstrating the assembly method of the electronic device which concerns on 1st Embodiment. The figure for demonstrating the assembly method of the electronic device which concerns on 1st Embodiment. The figure for demonstrating the assembly method of the electronic device which concerns on 1st Embodiment. Sectional drawing which expands and shows the notch part provided in the case of the electronic device which concerns on 2nd Embodiment. The top view of the electronic device which concerns on a comparative example.

The electronic device according to the first aspect of the embodiment is
A mounting board;
A case for housing the mounting substrate;
With
The mounting board is fastened to the case by at least one screw,
The corners of the mounting substrate that are not fastened are sandwiched between rib notches provided in the case.

  According to such an aspect, since the corner | angular part of the mounting board | substrate which is not fastened is pinched | interposed into the notch of the rib provided in the case, the deformation | transformation of the mounting board | substrate by external vibration can be suppressed. Thereby, it is possible to reduce a decrease in the bonding strength of the mounting component, and to improve the vibration resistance and impact resistance of the mounting substrate. In addition, by inserting the corner of the mounting board into the rib cutout while rotating the mounting board relative to the case, the corner of the mounting board that is not fastened is sandwiched between the rib cutout. The assembly process can be simplified.

An electronic device according to a second aspect of the embodiment is an electronic device according to the first aspect,
The rib is provided at a corner of the case,
The shape of the rib is asymmetric with respect to the diagonal of the case.

  According to such an aspect, since the rib shape is asymmetric with respect to the diagonal of the case, the corner of the mounting board is inserted into the notch of the rib while rotating the mounting board with respect to the case. The mounting board can be rotated only in one direction. Thereby, the mistake of the assembly direction of the case and the mounting board | substrate in an assembly process can be prevented.

An electronic device according to a third aspect of the embodiment is an electronic device according to the first or second aspect,
The notch of the rib has at least one protrusion that can be engaged with a recess in a corner of the mounting substrate.

  According to such an aspect, when the corner portion of the mounting substrate is inserted into the notch of the rib while rotating the mounting substrate with respect to the case, the protrusion of the notch is engaged with the recess of the corner portion of the mounting substrate. By doing so, the mounting substrate can be accurately positioned at a predetermined position. Thereby, workability | operativity in an assembly process improves.

An electronic device according to a fourth aspect of the embodiment is an electronic device according to any one of the first to third aspects,
An adhesive is filled between the notch of the rib and the corner of the mounting substrate.

  According to such an aspect, since the gap between the notch of the rib provided in the case and the corner of the mounting board becomes zero, the seismic performance of the mounting board can be further enhanced.

An electronic device according to a fifth aspect of the embodiment is an electronic device according to any one of the first to third aspects,
An elastic vibration-proof material is filled between the notch of the rib and the corner of the mounting substrate.

  Also according to such an aspect, since the gap between the notch of the rib provided in the case and the corner of the mounting board becomes zero, the seismic performance of the mounting board can be further improved.

An electronic device assembling method according to a sixth aspect of the embodiment includes:
The mounting board is accommodated inside the case at an angle where the corner of the mounting board does not hit the rib provided on the case,
While rotating the mounting substrate with respect to the case, insert the corner of the mounting substrate into the notch of the rib,
The mounting substrate is fastened to the case with at least one screw in a state where the corner portion of the mounting substrate is sandwiched between the notches of the ribs.

  According to such an aspect, since the corner | angular part of the mounting board | substrate which is not fastened is pinched | interposed into the notch of the rib provided in the case, the deformation | transformation of the board | substrate by external vibration can be suppressed. Thereby, it is possible to reduce a decrease in the bonding strength of the mounting component, and to improve the vibration resistance and impact resistance of the mounting substrate. In addition, by inserting the corner of the mounting board into the rib cutout while rotating the mounting board relative to the case, the corner of the mounting board that is not fastened is sandwiched between the rib cutout. The assembly process can be simplified.

  Hereinafter, specific examples of embodiments will be described in detail with reference to the accompanying drawings. In addition, in each figure, the component which has an equivalent function is attached | subjected the same code | symbol, and detailed description of the component of the same code | symbol is not repeated.

(First embodiment)
FIG. 1 is a plan view of an electronic device 10 according to the first embodiment. FIG. 2 is a view showing a cross section taken along the line AA of the electronic apparatus 10 shown in FIG. FIG. 3 is a view showing a cross section taken along line BB of the electronic apparatus 10 shown in FIG.

  The electronic device 10 according to the present embodiment can be used by being installed in an environment with a large external vibration such as an engine room of an automobile, and specifically, for example, an in-vehicle camera, but is particularly limited thereto. Is not to be done.

  As shown in FIGS. 1 to 3, the electronic apparatus 10 according to the present embodiment includes a mounting substrate 2 and a case 1 that accommodates the mounting substrate 2.

  In the illustrated example, the mounting substrate 2 has a substantially rectangular shape having four corners. At least one of the four corners of the mounting substrate 2 (the lower right corner in FIGS. 1 and 3) is formed with a notch that is penetrated by the screw 3, and another one corner. An arc-shaped depression is formed in (the lower left corner in FIGS. 1 and 3).

  On the other hand, the case 1 has a hollow box shape. The material of the case 1 may be a resin molded product or a metal material such as aluminum or stainless steel.

  As shown in FIGS. 1 and 3, the inner surface of the case 1 has a substantially quadrangular shape in plan view having four corners. At least one of the four corners of the inner surface of the case 1 is formed with a screw hole inserted by a screw 3, and the remaining three corners each have ribs 1a to 1b extending in the height direction. 1c is provided. Hereinafter, the three ribs 1a to 1c may be referred to as first to third ribs, respectively.

  4A is a perspective view of the case 1 viewed from the side opposite to the first rib 1a, and FIG. 4B is a perspective view of the case 1 viewed from the side opposite to the second rib 1b. These are the perspective views which looked at the case from the opposite side to the 3rd rib 1c.

  As shown in FIGS. 4A to 4C, the first to third ribs 1 a to 1 c are each formed with a notch at the same height position. The width of the notch is substantially the same as the thickness of the mounting substrate 2, and when the corner of the mounting substrate 2 is inserted into the notch, the corner of the mounting substrate 2 is sandwiched between the notches.

  In the example shown in FIG. 4c, at least one protrusion 1d is provided in the notch of the third rib 1c. The cross-section of the protrusion 1d has the same arc shape as the depression at the corner of the mounting substrate 2, and the corner of the mounting substrate 2 is inserted into the notch of the third rib 1c while the mounting substrate 2 is rotated. In this case, the notched protrusion 1 d can be engaged with a recess in the corner of the mounting substrate 2.

  As shown in FIG. 3, the shapes of the first to third ribs 1 a to 1 c in the notch portions are asymmetric with respect to the diagonal line of the case 1. Thus, after the mounting substrate 2 is accommodated inside the case 1 at an angle at which the corners of the mounting substrate 2 do not hit the ribs 1a to 1c of the corners of the case 1 (see FIG. 6A), the mounting substrate 2 is moved in one direction. When rotated counterclockwise (in the example shown in FIG. 3), the corners of the mounting substrate 2 can be inserted into the notches of the ribs 1a to 1c, but rotate in the other direction (clockwise in the example shown in FIG. 3). If it does so, the corner | angular part of the mounting substrate 2 will collide with rib 1a-1c, and it cannot insert in a notch.

(Assembly method)
Next, an assembling method of the electronic apparatus 10 having such a configuration will be described with reference to FIGS. 6A to 6D.

  First, as shown in FIG. 6A, the mounting substrate 2 is accommodated inside the case 1 at an angle at which the corners of the mounting substrate 2 do not hit the ribs 1 a to 1 c provided at the corners of the case 1.

  Next, as shown in FIG. 6B, the mounting substrate 2 is rotated relative to the case 1 and the corners of the mounting substrate 2 are inserted into the notches of the ribs 1a to 1c. At this time, since the shape of the first to third ribs 1a to 1c in the notch portion is asymmetric with respect to the diagonal line of the case 1, the mounting substrate 2 is directed in one direction (the direction of the arrow indicated by reference numeral 4). ) Can only be rotated. Therefore, it is possible to prevent an error in the assembly direction of the case 1 and the mounting substrate 2 in the assembly process.

  As shown in FIG. 6C, when the corners of the mounting substrate 2 are inserted into the notches of the ribs 1a to 1c, the corners of the mounting substrate 2 are sandwiched between the notches of the ribs 1a to 1c. At this time, the projection 1d of the third rib 1c is engaged with the recess in the corner of the mounting substrate 2, so that the mounting substrate 2 can be accurately positioned at a predetermined position.

  Thereafter, as shown in FIG. 6D, at least one screw 3 is inserted into the screw hole of the case 1 in a state where the corner notch of the mounting substrate 2 is penetrated, so that at least one screw 3 is used. The mounting substrate 2 is fastened to the case 1. In this state, the corners of the mounting substrate 2 that are not fastened are sandwiched from both sides of the front and back by the notches of the ribs 1a to 1c provided in the case 1, so that deformation of the mounting substrate 2 due to external vibration is effective. Can be suppressed.

  FIG. 5 is a graph showing a result of verification by the inventors of the vibration amplitude characteristics with respect to the frequency of external vibration by simulation. In FIG. 5, the solid line graph shows the simulation result of the electronic device 100 (see FIG. 8) according to the comparative example in which the mounting substrate is fixed to the case by two screws diagonally, and the broken line graph is the above-described graph. The simulation result of the electronic device 10 which concerns on this Embodiment shown is shown.

  With reference to FIG. 5, in the electronic device 10 according to the present embodiment, the corners of the mounting substrate 2 are sandwiched between the cutouts of the ribs 1a to 1c, so that the electronic device 100 according to the comparative example is compared with the electronic device 100 according to the comparative example. It was confirmed that the vibration amplitude at the time of resonance can be remarkably reduced and the frequency of the primary resonance point can be increased.

  As described above, according to the present embodiment, the corners of the mounting substrate 2 that are not fastened are sandwiched between the cutouts of the ribs 1a to 1c provided in the case 1, so that the mounting substrate 2 due to external vibration is used. Can be effectively suppressed. Thereby, it is reduced that the joint strength of the components mounted on the mounting substrate 2 is reduced, and the vibration resistance and impact resistance of the mounting substrate 2 can be improved.

  Further, according to the present embodiment, the mounting substrate 2 that is not fastened is inserted by inserting the corners of the mounting substrate 2 into the cutouts of the ribs 1 a to 1 c while rotating the mounting substrate 2 with respect to the case 1. Since the corner portion of the substrate is sandwiched between the notches of the ribs 1a to 1c, an additional component for restricting deformation of the corner portion of the mounting substrate 2 that is not fastened is unnecessary, and the number of components can be reduced. The assembly process can be simplified.

  Further, according to the present embodiment, since the shapes of the ribs 1a to 1c are asymmetric with respect to the diagonal line of the case 1, the corners of the mounting substrate 2 are ribbed while the mounting substrate 2 is rotated with respect to the case 1. When inserting into the notches 1a to 1c, the mounting substrate 2 can be rotated only in one direction. Thereby, the mistake of the assembly direction of case 1 and the mounting board | substrate 2 in an assembly process can be prevented.

  In addition, according to the present embodiment, at least one protrusion 1d is provided in the notch of the third rib 1c, and the corner of the mounting substrate 2 is moved to the ribs 1a to 1 while rotating the mounting substrate 2 with respect to the case 1. When inserted into the notch 1 c, the notch protrusion 1 d of the third rib 1 c can be engaged with the recess at the corner of the mounting substrate 2. Thereby, the mounting substrate 2 can be accurately positioned at a predetermined position, and workability in the assembly process is improved.

  Various changes can be made to the above-described embodiment. Hereinafter, an example of modification will be described with reference to the drawings. In the following description and the drawings used in the following description, the same reference numerals as those used for the corresponding parts in the above-described embodiment are used for parts that can be configured in the same manner as in the above-described embodiment, and overlapping Description to be omitted is omitted.

(Second Embodiment)
FIG. 7 is an enlarged cross-sectional view illustrating a notch portion of a rib provided in the case 1 of the electronic device 10 according to the second embodiment.

  In the example shown in FIG. 7, the filler 5 is filled between the notches of the ribs 1 a to 1 c and the corners of the mounting substrate 2. The filler 5 may be an adhesive or a vibration-proof material having elasticity such as rubber.

  According to such an aspect, in addition to obtaining the same effects as those of the first embodiment described above, the notches of the ribs 1a to 1c provided in the case 1 and the corners of the mounting substrate 2 can be used. Since the gap between them is filled with the filler 5 and becomes zero, the seismic performance of the mounting substrate 2 can be further enhanced.

  It should be noted that the above-described embodiment and the disclosure of the drawings are merely examples for explaining the invention described in the claims, and are described in the claims by the description of the above-described embodiments or the disclosure of the drawings. The invention made is not limited. The constituent elements of the above-described embodiment can be arbitrarily combined without departing from the gist of the invention.

DESCRIPTION OF SYMBOLS 10 Electronic device 1 Case 1a Rib 1b Rib 1c Rib 1d Protrusion 2 Mounting substrate 3 Screw 4 Arrow 5 which shows the rotation direction of a mounting substrate Filler

Claims (6)

A mounting board;
A case for housing the mounting substrate;
With
The mounting board is fastened to the case by at least one screw,
The corner portion of the mounting board that is not fastened is sandwiched between rib cutouts provided in the case,
An electronic device characterized by that. The rib is provided at a corner of the case,
The electronic device according to claim 1, wherein a shape of the rib is asymmetric with respect to a diagonal line of the case. 3. The electronic device according to claim 1, wherein the notch of the rib includes at least one protrusion that can be engaged with a recess in a corner portion of the mounting substrate. An adhesive is filled between the notch of the rib and the corner of the mounting substrate.
The electronic device according to claim 1, wherein the electronic device is an electronic device. The electronic apparatus according to claim 1, wherein a vibration-proof material having elasticity is filled between the notch of the rib and a corner portion of the mounting substrate. The mounting board is accommodated inside the case at an angle where the corner of the mounting board does not hit the rib provided on the case,
While rotating the mounting substrate with respect to the case, insert the corner of the mounting substrate into the notch of the rib,
An electronic device assembling method, wherein the mounting board is fastened to the case with at least one screw in a state where corners of the mounting board are sandwiched between the notches of the ribs.