JP5090282B2 - Circuit board unit - Google Patents

Description

  The present invention belongs to the technical field of a circuit board unit which is mainly mounted on a vehicle and incorporates a long board.

Conventionally, a substrate is housed in a protector comprising a case having a concave cross section and a lid for closing the opening of the case (see, for example, Patent Document 1).
Japanese Unexamined Patent Publication No. 2002-10440 (page 2-6, all figures)

  However, in the past, handling in the factory, handling, etc. is difficult, stress is applied to the circuit board and circuit body accommodated, and stress is applied to solder, electrical connection parts, etc., causing problems. There was a problem.

  The present invention has been made paying attention to the above-mentioned problems, and the purpose of the present invention is to add stress to the circuit board, circuit body, etc., and to reduce the stress to solder, electrical connection parts, etc. An object of the present invention is to provide a circuit board unit capable of preventing a problem.

  In order to achieve the above object, in the present invention, in a circuit board unit that accommodates a long circuit board having a solder portion in a space formed by an upper case and a lower case, and has flexibility in at least the longitudinal direction. A plurality of engagement recesses provided at intervals along one edge of the upper case and the lower case, and provided at least along the longitudinal direction of the circuit board; and the other edge of the upper case and the lower case Engaging protrusions provided so as to be paired with the engaging recesses, and the engaging recesses and side surfaces of the engaging protrusions are partially in the longitudinal direction of the circuit board. In a state of being opposed to each other in a state of being separated, they are separated in a state where they are horizontally supported, and in a support state in which bending occurs, they are in contact within a range not exceeding the allowable limit of the strain value of the solder part. And butterflies.

  Therefore, in the present invention, a stress is applied to the circuit board, the circuit body, etc., and the stress to the solder, the electrical connection portion, etc. can be reduced, so that no trouble is caused.

  Hereinafter, an embodiment for realizing a circuit board unit of the present invention will be described based on Example 1 corresponding to the invention according to claims 1, 2, 3, 4, 5 and 6.

First, the configuration will be described.
FIG. 1 is an explanatory perspective view showing a vehicle assembly state of the circuit board unit according to the first embodiment. FIG. 2 is an explanatory diagram illustrating a vehicle assembly state of the circuit board unit according to the first embodiment.
In the first embodiment, an example in which a pre-assembled cockpit module 51 is mounted at once on the vehicle body of the vehicle is taken as an example. In this case, the circuit board unit 1 is attached to a cross car beam 50 provided inside the instrument panel as a structural member of the cockpit module 51.
The circuit board unit 1 is responsible for part of the power supply wiring and signal wiring in the left-right direction of the vehicle. Also, some electronic components may be mounted.

FIG. 3 is a perspective view of the circuit board unit according to the first embodiment. FIG. 4 is a perspective view illustrating an exploded state of the circuit board unit according to the first embodiment.
The circuit board unit 1 has a structure in which two upper and lower bodies of a resin upper case 2 and a lower case 3 are assembled, and a circuit board 4 is accommodated therein.
First, the structure of the upper case 2 will be described.
The upper case 2 constitutes a recess for accommodating the lower case 3 on the bottom surface side by a peripheral side wall portion 21 which is a peripheral side wall. When the lower case 3 is accommodated, the peripheral side wall 21 has a frame-like structure on the outer peripheral side of the lower case 3.

Next, screw receiving portions (engaging recesses) 22 for attaching the lower case 3 are provided at a plurality of locations on the peripheral edge of the upper case 2. In the portion where the screw receiving portion 22 is provided, the peripheral side wall portion 21 is notched. Details will be described later.
Specifically, seven pieces are provided on each of the front and rear sides.
In addition, engaging claw portions 23 for temporary fixing to the lower case 3 are provided at a plurality of locations on the peripheral edge of the upper case 2. The peripheral side wall 21 is also notched at the portion where the engaging claw 23 is provided.

Furthermore, on the upper surface of the upper case 2, attachment portions 24 that allow attachment to other cables and ducts are provided at a plurality of locations in the left and right longitudinal directions at the center in the front-rear direction.
Next, at the three locations on the front side of the upper case 2, there are tongue pieces extending vertically downward, and at the two locations on the back side, tongue pieces extending horizontally toward the back side, mounting holes The attachment part 25 provided with is provided. The attachment portion 25 is used for attachment to the cross car beam 50.
Further, the left and right end portions of the upper case 2 are provided with mounting portions 26 each having a tongue shape extending horizontally to the left and right and provided with mounting holes. The attachment portion 26 is used for attachment to the cross car beam 50.

FIG. 5 is a partially enlarged bottom view of the screw receiving portion of the upper case. 6 is a partially enlarged front explanatory view of a portion of a screw receiving portion of the upper case when the upper case shown in FIG. 5 is viewed from above.
As shown in FIGS. 5 and 6, the screw receiving portion 22 of the upper case 2 has a structure in which the screw receiving portion 22 partially protrudes laterally from a cutout portion 21 a obtained by cutting out the peripheral side wall portion 21. As shown in FIG. 6, the screw receiving portion 22 is provided in the cutout portion 21 a, so that the receiving surface is positioned above the lower end of the peripheral side wall portion 21.
In addition, the peripheral side wall part 21 of the part provided with the notch part 21a is made into a wall surface substantially perpendicular | vertical to an up-down direction and a near side direction. This portion is denoted by reference numeral 21b.
Further, the screw receiving portion 22 is provided with a screw hole 22a. In the first embodiment, a screw hole 22a that does not penetrate is used, and a water droplet from above is not directed to the inside.

Next, the structure of the lower case 3 will be described.
The lower case 3 constitutes a recess for accommodating the circuit board 4 on the upper surface side by a peripheral side wall portion 31 which is a peripheral side wall. When the circuit board 4 is accommodated, the peripheral side wall 31 has a frame-like structure on the outer peripheral side of the circuit board 4.
Next, screw fixing portions 32 for attachment to the upper case 2 are provided at a plurality of locations on the peripheral portion of the lower case 3 and corresponding to the screw receiving portions 22 of the upper case 2. The screwing portion 32 is provided so as to protrude further from the peripheral side wall portion 31 to the outer peripheral side. Details will be described later.
Further, at a plurality of locations on the peripheral edge of the lower case 3, the engagement claw portions are bent over the engagement claw portions 23 of the upper case 2 at locations corresponding to the engagement claw portions 23 of the upper case 2. A U-shaped (frame shape) engaging portion 33 that is hooked on and engaged with 23 is provided.

FIG. 7 is a partially enlarged front view of a portion of a screw fixing portion of the lower case. FIG. 8 is a partially enlarged bottom view for explaining the screw fixing portion of the lower case.
The screwing portion (engagement convex portion) 32 is formed in a shape having a projecting portion 32a that projects linearly outward. And it has the structure which provides the through-hole 32c through which the screw | thread 5 penetrates the seat part 32b of the circular recessed part from which the screw head of the screw 5 for fastening seats with a washer from the bottom face.
The overhanging portion 32a has a wall surface that is substantially perpendicular to the vertical direction and the front direction. However, the draft of the mold is allowed.

Next, the circuit board 4 will be described.
The circuit board 4 is configured to be accommodated in a portion surrounded by the peripheral side wall portion 31 of the lower case 3, and has a structure in which the circuit board 4a and the circuit board 4b divided into the left and right are connected by a flat cable 4c at the center.

Next, the attachment structure of the upper case 2 and the lower case 3 will be described.
FIG. 9 is a partially enlarged explanatory view of a fastening portion of the upper case and the lower case of the circuit board unit according to the first embodiment. FIG. 10 is a partially enlarged cross-sectional view of a fastening portion between the upper case and the lower case of the circuit board unit according to the first embodiment.
As shown in FIGS. 9 and 10, the fastening portion between the upper case 2 and the lower case 3 is inserted into the cutout portion 21 a of the peripheral side wall portion 21 of the upper case 2 in the vertical direction. And it fastens with the screw 5 which has a washer in a head from the downward direction.

The fastened screw 5 is engaged with the screw fixing portion 32 of the lower case 3 together with the washer, and the screw portion is screwed into the screw hole 22 a of the screw receiving portion 22 of the upper case 2.
As a result, the upper surface of the screw fixing portion 32 of the lower case 3 comes into contact with and closely contacts the bottom surface of the screw receiving portion 22 of the upper case 2. The wall structure 21b of the peripheral side wall portion 21 of the upper case 2 and the protruding portion 32a of the screwing portion 32 of the lower case 3 are attached to each other with a predetermined gap as shown in FIG.

FIG. 11 is a bottom perspective view of an end portion of the circuit board unit according to the first embodiment.
In the fastening structure of the upper case 2 and the lower case 3, in the portion that is the end in the left-right direction, the protruding portion 32a on the end side of the protruding portion 32a of the screwing portion 32 of the lower case 3 is Make the shape extending diagonally.
And the magnitude | size and shape of the notch part 21a of the peripheral side wall part 21 of the upper case 2 of the location corresponding to this are also made into the shape which notched diagonally. Thereby, the wall surface portion 21b at this position has an inclined shape.
In other words, the protruding portion 32a and the wall surface portion 21b at the four corners on the bottom surface of the circuit board unit 1 are structured to be inclined like a C chamfered shape.

Furthermore, on the left and right sides of the bottom surface of the lower case 3, there are provided portions where connectors 4d for electrical connection between the accommodated circuit board 4 and the equipment of the cockpit module are exposed. The connector 4d is attached to the circuit board 4 in advance and is electrically connected. In FIG. 3, the connector mounting positions on the circuit boards 4a and 4b are indicated by reference numeral 4d.
The lower case 3 is provided with a connector protection portion 34 that surrounds the periphery of the connector 4d with a side wall.

FIG. 12 is an explanatory diagram illustrating a substrate holding structure of the circuit board unit according to the first embodiment.
As a holding structure of the circuit board 4, a holding portion 35 that is one step higher than the center side of the lower case 3 is provided inside the peripheral side wall portion 31 of the lower case 3. The holding unit 35 is provided continuously or intermittently. On the lower surface of the upper case 2, pressing portions 27 protruding downward are provided at a plurality of locations.
Then, inside the peripheral side wall portion 31 of the lower case 3, the peripheral portion of the circuit board 4 is held from below by the holding portion 35, and a part of the circuit board 4 is held from above by the holding portion 27 provided in the upper case 2. Try to hold it down. That is, the circuit board 4 is held so as to be sandwiched.

The operation will be described.
[Distribution and wiring of cockpit module]
The circuit board unit 1 according to the first embodiment is attached to the cross car beam 50 of the cockpit module 51 and transmits power in the left-right direction and transmits / receives signals in the cockpit module 51. Therefore, the inside of the instrument panel of the cockpit module 51 is simplified in wiring and has a very space-saving configuration.
In addition, since a plurality of mounting portions 24 are provided in the left-right direction on the upper surface of the circuit board unit 1, wiring is performed in a bundle shape in the left-right direction using the upper surface of the circuit board unit 1. You may make it fix an electric wire and a signal wire | line.

  Further, since power is supplied and signal lines are connected from the plurality of connectors 4d provided on the bottom surface of the circuit board unit 1, the inside of the instrument panel of the cockpit module 51 has a very simple wiring structure.

[Action to reduce the stress of the circuit board]
FIG. 13 is an explanatory diagram showing a carry-in state for mounting the cockpit module to which the circuit board unit of Example 1 is attached to a vehicle.
The cockpit module 51 is a module in which, for example, an instrument panel, a steering column, a meter, an air conditioning unit, an air conditioning duct, an audio unit, and the like are modularized and mounted on a vehicle body.
When the cockpit module 51 is mounted on the vehicle body, the cockpit module 51 is loaded while holding both ends of the cross car beam 50. Then, the weight of the cockpit module 51 is concentrated at the center of the cross car beam 50, and a phenomenon of bending like a bow occurs (see FIG. 13).

Since the circuit board unit 1 according to the first embodiment is attached to the cross car beam 50, a stress that causes the same bending is generated.
The circuit board unit 1 accommodates a circuit board 4 therein. Since the solder joint portion of the circuit board 4 to the connector 4d and the like and the circuit pattern portion (which are referred to as solder portions) are weaker than the resin of the upper case 2 and the lower case 3 with respect to stress and deflection, there is a problem. It becomes easy to occur and becomes a problem. The upper case 2 and the lower case 3 are made of resin and have a certain degree of flexibility.

  In this case, in the circuit board unit 1 according to the first embodiment, the stress is received by contact and adhesion between the bottom surface of the screw receiving portion 22 of the upper case 2 that is fastened and the top surface of the screw fixing portion 32 of the lower case 3. Try to suppress bending. However, since this bending is substantially orthogonal to the fastening direction, it is difficult to effectively suppress it with a fastening force. Therefore, with respect to the direction substantially perpendicular to the fastening direction, that is, with respect to the screw receiving portion 22 of the upper case 2, the screwing portion 32 of the lower case 3 moves so as to be displaced outward in the left-right direction, and further bending occurs. become.

  At this time, in the support state in which the distortion exceeds the allowable limit of the distortion value of the solder portion of the circuit board 4, the screwing portion 32 of the lower case 3 is disposed in the notch portion 21 a of the peripheral side wall portion 21 of the upper case 2. Therefore, the wall surface portion 21b of the peripheral side wall portion 21 of the upper case 2 and the protruding portion 32a of the screwing portion 32 of the lower case 3 are in contact with each other in a direction substantially perpendicular to the fastening direction. As a result, the positional deviation between the upper case 2 and the lower case 3 is limited. Therefore, the bending of the circuit board unit 1 is suppressed.

In other words, in addition to receiving the stress caused by the weight of the circuit board unit 1 caused by the weight of the cockpit module by the fastening of the upper case 2 and the lower case 3 and the contact surface, the deflection The upper and lower two-body structure tends to be displaced when it is generated, but this is received by the contact in the position displacement direction of the upper and lower members. Reduce. Thereby, the bending of the circuit board unit 1 is suppressed.
For this reason, even if both ends of the cross car beam 50 are supported when the cockpit module 51 is transported, no problem occurs.

  In addition, since the circuit board 4 is configured such that the circuit boards 4a and 4b are connected by a central flat cable, even when the cockpit module 51 is transported, even if the bending occurs at the central position where the bending amount is the largest, the circuit board 4 No problem occurs in 4.

Further explanation will be given.
FIG. 14 is an explanatory diagram of a cantilever state of the circuit board unit according to the first embodiment.
The circuit board unit 1 according to the first embodiment is a long object close to the left and right length of the cockpit module of the vehicle. Therefore, when the circuit board unit 1 is assembled or attached to the cross car beam 50, the circuit board unit 1 may be in a cantilever state in which one end of the circuit board unit 1 is held by an operator's hand or machine.
At that time, the circuit board unit 1 is bent due to the operation and the reaction thereof, as shown in FIG.

The point where this bending is not preferable is as described above, and if the work is performed so that this bending does not occur or is not in a cantilever state, work efficiency is reduced and work machine cost is increased. Become.
In the circuit board unit 1 of the first embodiment, the wall surface portion 21b of the peripheral side wall portion 21 of the upper case 2 and the protruding portion 32a of the screwing portion 32 of the lower case 3 are brought into contact with each other in a direction substantially perpendicular to the fastening direction. The stress that causes the bending is reduced by the operation, the reaction thereof, and the weight of the circuit board unit 1, and the bending is suppressed. Therefore, it is possible to prevent problems and improve the workability.

Further explanation will be given.
In the assembly structure and method of the circuit board unit 1 according to the first embodiment, the circuit board 4 is accommodated so as to be placed from above on the inside surrounded by the peripheral side wall 31 of the lower case 3 in a frame shape. The upper case 2 is assembled from above 3.
Since the lower surface of the upper case 2 has a recess surrounded by a peripheral side wall 21 in a frame shape, the lower case 3 is accommodated here.
At that time, the screwing portion 32 of the lower case 3 is inserted into the cutout portion 21 a of the peripheral side wall portion 21 of the upper case 2, and the engaging portion 33 of the lower case 3 is inserted into the engaging claw portion 23 of the upper case 2. Is temporarily engaged so that the two engage with each other.

Then, the temporarily fixed state is turned upside down, and the screw is inserted into the screw fixing portion 32 of the lower case 3 from above to be fastened. And when fastening is complete | finished, the front and back are reversed again, and attachment to the crosscar beam 50 is performed after that.
Alternatively, when the cable is further assembled to the attachment portion 24 for wiring, it is necessary to perform reversal so that the attachment portion 24 is on the front side.
With such an assembly structure, the circuit board unit 1 of the first embodiment takes into consideration the waterproofness of the circuit board 4.
In other words, the circuit board 4 is not cut out, but is surrounded by the peripheral side wall 31 of the lower case 3 having the lower end as a base end, and further, has a cutout portion 21a on the outer side, and the upper end is the base end. The upper case 2 is surrounded by the peripheral side wall 21. As a result, even if water droplets are transmitted through the peripheral side wall portion 21 of the upper case 2, the peripheral side wall portion 31 located on the inner side prevents water droplets or the like from entering the accommodation space of the circuit board 4. Further, the fastening screw 5 for assembling the upper case 2 and the lower case 3 is assembled from the bottom surface side, and the seating portion 32b of the circular concave portion of the screwing portion 32 is opened at the lower portion. Prevent accumulation of water droplets.

FIG. 15 is an explanatory diagram of a twisted state of the circuit board unit according to the first embodiment.
Due to such consideration for waterproofness, the circuit board unit 1 of the first embodiment is inverted when the circuit board unit 1 of the first embodiment is assembled and thereafter attached, and this inversion causes a torsional stress in the circuit board unit 1. It will be.
In the case of twisting, the upper case 2 and the lower case 3 tend to be displaced by stress at the ends that are long sides in the longitudinal direction. This displacement is, on the one hand, the upper case 2 extending and the lower case 3 contracting, and on the other hand the opposite. That is, as in the case of bending, the upper case 2 and the lower case 3 tend to be twisted by causing a positional shift in a direction substantially orthogonal to the fastening direction.

The point where this twist is not preferable is the same as in the case of bending as described above. If the reversing operation is performed by adjusting the force and speed so that this twist does not occur, the work efficiency is lowered and the cost of the work machine is reduced. It will increase.
In the circuit board unit 1 of the first embodiment, the wall surface portion 21b of the peripheral side wall portion 21 of the upper case 2 and the protruding portion 32a of the screwing portion 32 of the lower case 3 are brought into contact with each other in a direction substantially perpendicular to the fastening direction. Since the stress that twists the circuit board unit 1 generated during the reversal is reduced and the twist is suppressed, it is possible to prevent problems and improve workability.

In order to clarify the operation of the first embodiment, further explanation will be added below.
FIG. 16 is an explanatory view showing an example of a fastening structure of the upper case and the lower case.
In order to fasten the upper case 2 and the lower case 3, a configuration as shown in FIG. 16 may be considered.
In the fastening structure shown in FIG. 16, a screw receiving portion 60 for screwing a screw 62 to be fastened is provided in the upper case 2, and a screw fixing portion 61 for engaging the head of the screw 62 and a washer is provided in the lower case 3. Furthermore, the screwing portion 61 is provided with a long hole 61a for allowing the screw portion to pass therethrough. The screw receiving portion 60 of the upper case 2 and the screw fixing portion 61 of the lower case 3 are brought into contact with each other, and the screw 62 is fastened from below.

In the fastening structure shown in FIG. 16, in order to allow positional displacement in the longitudinal direction during temporary fastening and fastening of the upper case 2 and the lower case 3, a hole (elongate hole 61a) for penetrating the screw portion is a long hole. It is in shape.
However, in the fastening structure shown in FIG. 16, the upper case 2 and the lower case 3 are prevented from being misaligned when the cockpit module is transported, cantilevered or twisted. Only the fastening force in the direction substantially perpendicular to the displacement direction is obtained. For this reason, the upper case 2 and the lower case 3 are displaced due to the magnitude of the stress, resulting in problems due to bending and twisting.

  In the first embodiment, when the upper case 2 and the lower case 3 are assembled, the screwing portions 32 of the lower case 3 are inserted into the notches 21 a of the peripheral side wall portion 21 of the upper case 2. As a result, the longitudinal positioning when the upper case 2 and the lower case 3 are temporarily fixed is performed. Then, temporary engagement is performed so that the engagement portion 33 of the lower case 3 engages with the engagement claw portion 23 of the upper case 2. In the engagement between the engagement claw portion 23 and the engagement portion 33, a dimension and a size that allow positional displacement in the longitudinal direction may be set.

With the fastening structure that also serves as the temporary fixing structure, in the circuit board unit 1 according to the first embodiment, when the upper case 2 and the lower case 3 are fastened with screws, there is no positional displacement in the longitudinal direction.
Therefore, unlike the fastening structure shown in FIG. 16, there is no need for a configuration like a long hole having a dimension that allows a deviation at the time of fastening.
In the first embodiment, the gap between the wall surface portion 21b of the cutout portion 21a of the peripheral side wall portion 21 of the upper case 2 and the projecting portion 32a of the screw fixing portion 32 of the lower case 3 is obtained by adopting such a structure for temporarily fixing. Can be narrowed. This is advantageous in that the stress can be reduced by contacting the wall surface portion 21b and the overhanging portion 32a at an early stage when the stress is generated.

  Further, a plurality of wall surface portions 21b and overhanging portions 32a of the circuit board unit 1 of the first embodiment are provided, but the four corner portions are inclined like a C chamfered shape as shown in FIG. Even when subjected to stress that bends obliquely with respect to the direction, the stress can be reduced by having a portion that is in contact with the direction.

In the circuit board unit 1 according to the first embodiment, the circuit board 4 is held by the holding part 35 of the lower case 3 and the pressing part 27 of the upper case 2 so as to be sandwiched. In this holding structure, the circuit board 4 is only pressed in the direction of the lower case 3 from at least the upper case 2 and is not restricted in the longitudinal direction. Therefore, consideration is given so that the stress of the circuit board 4 is not increased due to the holding structure being bent or twisted.
Furthermore, in the circuit board unit 1 according to the first embodiment, in comparison between the upper case 2 and the lower case 3, the upper case 2 is more bent in the direction of bending due to the weight of the cockpit module 51 than the lower case 3 that directly accommodates the circuit board 4. It is easy to bend. That is, while the lower case 3 has the peripheral side wall portion 31 without a cutout, the upper case 2 is provided with a cutout portion 21a in the peripheral side wall portion 21 so that the cutout portion 21a is easily bent. Thus, the upper case 2 is largely bent as compared with the lower case 3 to absorb the stress, so that this two-body structure does not increase the stress of the circuit board 4.

Next, the effect will be described.
In the circuit board unit of the first embodiment, the effects listed below can be obtained.

  (1) A long circuit board 4 having a solder portion is accommodated in a space formed by the upper case 2 and the lower case 3, and the upper case 2 in the circuit board unit 1 having flexibility at least in the longitudinal direction. A plurality of peripheral edges are provided at intervals, and at least along the longitudinal direction of the circuit board, the peripheral side wall 21 is provided with a notch 21 a and a screw receiving part 22, and the other side edge of the lower case 3 is provided with a peripheral side wall. A screwing portion 32 provided so as to be paired with the notch portion 21a of the portion 21 and the screw receiving portion 22, and a wall surface portion 21b of the notch portion 21a of the peripheral side wall portion 21 and an overhanging portion 32a of the screwing portion 32. Are opposed to each other in a state where a part of the circuit board 4 is separated in the longitudinal direction, are separated in a state where they are supported horizontally, and are allowed to bend in a supporting state in which bending occurs. Since the contact is made within a range not exceeding the limit, it is possible to reduce the stress on the solder of the circuit board 4 and the electrical connection portion by suppressing the upper case 2 and the lower case 3 from causing the displacement. It is possible not to give a fault.

  (2) In the above (1), since the support state causing the deflection is at least a cantilever support state, if the deflection due to its own weight due to the cantilever support state or the deflection due to the reaction due to the cantilever state is about to occur, the peripheral edge Since the wall surface portion 21b of the notch portion 21a of the side wall portion 21 and the protruding portion 32a of the screwing portion 32 are in contact with each other to suppress displacement, for example, even in a cantilever support state in the manufacturing process, It is possible to reduce the stress on the electrical connection portion and the like so as not to cause a problem.

  (3) In the above (1) or (2), the screwing portion 32 includes a seating portion 32b that receives the head portion of the screw 5 and a through hole 32c that penetrates the screw portion, and the notch portion 21a of the peripheral side wall portion 21. The upper case 2 and the lower case 3 are assembled by engaging and fastening the screw holding portion 32 to the screw receiving portion 22, and the notch portion 21 a and the screw receiving portion 22 and the screw fixing portion of the peripheral side wall portion 21 are assembled. 32 is used as a means for restricting the positional displacement of the upper case 2 and the lower case 3 in the longitudinal direction of the circuit board before and during fastening, so that the upper and lower sides of the assembled upper case 2 and lower case 3 are reversed before fastening. By restricting the position so that it does not shift at the time of fastening or at the time of fastening, and making the contact and proximity of the wall surface portion 21b and the overhanging portion 32a face each other within a predetermined dimension, the stress reduction action can be reliably performed. That. In addition, since the stress reducing action also serves as a fastening portion, the structure is simplified and the stress can be reduced without increasing the cost.

  (4) In the above (1) to (3), a frame-shaped peripheral side wall 21 that protrudes downward and accommodates the lower case 3 is provided at the periphery of the bottom surface of the upper case 2, and the peripheral side wall 21 is provided at a plurality of locations. Since the notch portion 21a is provided as the notch portion 21a and the screw receiving portion 22 to which the screw portion of the screw 5 is screwed is provided at the notched position, the screw receiving portion 32 that is aligned with the screw receiving portion 22 and receives the head of the screw is provided. However, by engaging with the wall surface portion 21b of the peripheral side wall portion 21 of the notch portion 21a, the lower case 3 is accommodated on the side of the upper case 2 for performing the stress reducing operation. It is formed by cutting out a part of the peripheral side wall portion 21 of the steel plate, and stress can be reduced while reducing cost and saving space.

Further, by providing a cutout portion 21a in the peripheral side wall portion 21 that is located on the outer side of the peripheral side wall portion 31 of the lower case 3 and protrudes downward, water drops and the like can be improved, and the waterproofness of the circuit board 4 can be improved. Can do.
Furthermore, by providing the notch 21a in the peripheral side wall 21 of the upper case 2, the upper case 2 can bend more easily than the lower case 3, and the upper case 2 can be greatly bent compared to the lower case 3 that directly accommodates the circuit board 4. Thus, the stress is absorbed, and the two-body structure of the upper case 2 and the lower case 3 can prevent the stress of the circuit board 4 from being increased.

  (5) In the above (1) to (4), the circuit board 4 is held by the upper case 2 and the lower case 3 so that the circuit board 4 is sandwiched from above and below. The generation of stress on the substrate 4 can be suppressed.

  (6) In the above (1) to (5), the circuit board unit 1 is attached to the cross car beam 50 which is a structural member of the cockpit module 51 so that the vehicle left-right direction of the cockpit module 51 is the longitudinal direction. The supporting state that causes the bending is a state in which the cockpit module 51 is supported at both ends of the cross car beam 50. Therefore, the circuit board unit 1 is bent when the cockpit module 51 is bent by its own weight. This can reduce the bending of the circuit board 4 accommodated thereby, can reduce the stress on the solder and the electrical connection portion of the circuit board 4, and the like can be prevented.

  The circuit board unit of the present invention has been described based on the first embodiment. However, the specific configuration is not limited to these embodiments, and the gist of the invention according to each claim of the claims. As long as they do not deviate, design changes and additions are permitted.

In Example 1, although the circuit board 4 which consists of two bodies on either side was demonstrated as an example, it may consist of more than one or may be one body thing.
The circuit board 4 according to the first embodiment may be either a circuit board 4 that has almost no electronic components mounted thereon or a circuit board that is sufficiently mounted with electronic components for power supply and signal transmission.

FIG. 3 is an explanatory perspective view illustrating a vehicle assembly state of the circuit board unit according to the first embodiment. It is explanatory drawing which shows the vehicle assembly state of the circuit board unit of Example 1. FIG. 1 is a perspective view of a circuit board unit according to Embodiment 1. FIG. It is a perspective view which shows the decomposition | disassembly state of the circuit board unit of Example 1. FIG. It is a partially expanded bottom view explanatory drawing of the part of a screw receiving part of an upper case. It is a partially expanded front explanatory view of the screw receiving portion of the upper case. It is a partial expanded front view of the part of the screwing part of a lower case. It is a partially expanded bottom view explanatory drawing of the part of the screwing part of a lower case. FIG. 3 is a partially enlarged explanatory view of a fastening portion between the upper case and the lower case of the circuit board unit according to the first embodiment. FIG. 3 is a partially enlarged cross-sectional view of a fastening portion between an upper case and a lower case of the circuit board unit according to the first embodiment. 3 is a bottom perspective view of an end portion of the circuit board unit according to Embodiment 1. FIG. FIG. 3 is an explanatory diagram illustrating a substrate holding structure of the circuit board unit according to the first embodiment. It is explanatory drawing which shows the carrying-in state for mounting to the vehicle of the cockpit module to which the circuit board unit of Example 1 was attached. It is explanatory drawing of the cantilever state of the circuit board unit of Example 1. FIG. It is explanatory drawing of the twisted state of the circuit board unit of Example 1. FIG. It is explanatory drawing which shows the example of the fastening structure of an upper case and a lower case.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Circuit board unit 2 Upper case 21 Peripheral side wall part 21a Notch part 21b Wall surface part 22 Screw receiving part 22a Screw hole 23 Engagement claw parts 24-26 Mounting part 27 Holding part 3 Lower case 31 Peripheral side wall part 32 Screw stop part 32a Overhang | projection part 32b Seat part 32c Through-hole 33 Engagement part 34 Connector protection part 35 Holding part 4 Circuit board 4a Circuit board 4b Circuit board 4c Flat cable 4d Connector 5 Screw 50 Crosscar beam 51 Cockpit module 60 Screw receiving part 61a Slot 61 61 Screw fixing Part 62 Screw

Claims (6)

In a circuit board unit that accommodates a long circuit board having a solder portion in a space formed by an upper case and a lower case, and has flexibility in at least the longitudinal direction,
A plurality of engagement recesses provided at intervals along one side edge of the upper case and the lower case, and provided along at least the longitudinal direction of the circuit board;
An engaging projection provided on the other edge of the upper case and the lower case so as to be paired with the engaging recess;
With
The engagement recess and the side surface of the engagement projection are opposed to each other in a state where a part thereof is separated in the longitudinal direction of the circuit board, and are separated in a state where they are horizontally supported, and support that causes bending. In the state, contact within a range not exceeding the allowable limit of the distortion value of the solder part,
A circuit board unit characterized by that. The circuit board unit according to claim 1,
The support state causing the deflection is at least a cantilever support state.
A circuit board unit characterized by that. In the circuit board unit according to claim 1 or 2,
The engaging convex portion includes a seating portion that receives the head portion of the screw, and a through hole that penetrates the screw portion,
By engaging the engagement convex portion with the engagement concave portion and fastening it, the upper case and the lower case are assembled.
The engagement between the engagement concave portion and the engagement convex portion is used as a means for restricting positional deviation in the longitudinal direction of the circuit board between the upper case and the lower case before and during fastening.
A circuit board unit characterized by that. In the circuit board unit according to any one of claims 1 to 3,
Provided on the periphery of the bottom surface of the upper case is a frame-shaped peripheral side wall that protrudes downward and accommodates the lower case inside,
The peripheral side wall portion is cut out at a plurality of locations, and a receiving portion for screwing a screw portion of a screw is provided at the notched position to form the engaging recess.
A circuit board unit characterized by that. In the circuit board unit according to any one of claims 1 to 4,
With the upper case and the lower case, the circuit board is held so as to be sandwiched from above and below,
A circuit board unit characterized by that. In the circuit board unit according to any one of claims 1 to 5,
The circuit board unit is attached to the cross car beam, which is a structural member of the cockpit module, so that the vehicle left-right direction of the cockpit module is the longitudinal direction,
The support state that causes bending is a state in which the cockpit module is supported at both ends of the cross car beam.
A circuit board unit characterized by that.

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