JP7709116B2 - Board mounting structure - Google Patents

Description

The present invention relates to a substrate mounting structure in which a first substrate and a second substrate on which electronic components are mounted are connected using a plurality of rod-shaped relay terminals, and a spacer substrate having these multiple relay terminals is placed between the first substrate and the second substrate.

Conventionally, examples of such substrate mounting structures include those shown in Patent Document 1 (see [0010], [0014], [0022] and Figures 2 and 7).

This board mounting structure has a structure in which, for example, a control board 11 and a power board 12 are stacked, with a connector case 13 interposed between these boards. Insert-molded terminal groups 131, 132, and 133 are mounted on the periphery of the connector case 13, and these terminals electrically connect, for example, the mounted components of the control board 11 and the mounted components of the power board 12.

With this configuration, the components mounted on the control board 11 and the components mounted on the power board 12 can be connected via the terminal group, eliminating the need to run wires to connectors located far away due to the constraints of mounting position that were necessary when these were arranged on a flat surface. This simplifies the wiring layout and increases the freedom of wiring design.

JP 2013-103535 A

In the above-mentioned conventional board mounting structure, the terminals are insert-molded into the wall of the connector case, and the individual terminals cannot be displaced relative to each other in the insert molded portion. Therefore, even if the power board 12 overheats and the relative positions of the soldered portions on the power board 12 change due to thermal expansion or the like, the positions of the terminals are fixed by the insert mold. This leaves the possibility that the soldered portions on the power board 12 may be damaged.

In addition, the terminal in this known document is structured so that it protrudes from the middle of the wall of the connector case toward the center along the planar direction of the connector case and is bent immediately adjacent to it so as to face the other board. With this configuration, the position of the tip of the terminal can be easily changed, and soldering is easy even if the soldering position on the target board is misaligned. It is also presumed that if the target board thermally expands, the terminal itself will deform, making it possible to absorb the effects of thermal expansion.

However, to create a terminal group with this configuration, it is necessary to insert-mold the numerous terminals while lining them up so that the bent portions are embedded in the "L" shape, making the manufacturing process extremely cumbersome.

Furthermore, if a process is required to bend all the terminals toward the target board after insert molding is completed, the process becomes even more time-consuming.

As such, conventional substrate mounting structures have various issues that need to be resolved, and there is a demand for a substrate mounting structure that is simple in structure and has excellent heat resistance.

(Characteristics)
The characteristic configuration of the substrate mounting structure according to the present invention is as follows:
The electronic component mounting device includes a first substrate and a second substrate on which electronic components are mounted, and a spacer substrate provided between the first substrate and the second substrate;
the spacer substrate includes a plurality of regions provided via partitions such that a relative distance between the regions changes based on an external force acting along a planar direction of the spacer substrate;
rod-shaped relay terminals that electrically connect the soldering portions of the first board and the soldering portions of the second board are distributed and disposed in a penetrating state in each of the plurality of regions;
a ground terminal for the first substrate or the second substrate is provided on at least one of a first fixing portion of the first substrate fixed to a housing and a second fixing portion of the second substrate fixed to the housing;
The housing has a frame member which is attached to the housing while holding the first substrate, the second substrate, and the spacer substrate together in advance, and a part of the frame member has a pressing portion which presses a part of the first substrate or the second substrate toward the housing, and a heat dissipation portion is formed on the side opposite the pressing portion of a portion of the first substrate or the second substrate which faces the pressing portion, and a heat dissipation sheet is arranged on the side of the housing which abuts the heat dissipation portion when the frame member is attached .

(effect)
In this configuration, the first and second substrates are arranged in two stages, and the two substrates are connected by a spacer substrate having a plurality of rod-shaped relay terminals. The spacer substrate is divided into several regions by partitions, and the rod-shaped relay terminals are distributed among these regions.

The relative distance between these multiple regions can change based on an external force acting along the planar direction of the spacer substrate. For example, when the first substrate and the second substrate are heated, and the soldered portion on the first substrate and the soldered portion on the second substrate are in different heated states, the soldered portions may be displaced relative to each other when viewed in a direction perpendicular to the substrate. In this case, the regions of the spacer substrate are displaced relative to each other along the planar direction, allowing the relay terminals to be displaced relative to each other, thereby reducing stress generated in the soldered portion on the first substrate or the second substrate.

This prevents breakage of the soldered parts and damage to the board, improving heat resistance and durability. In other words, by configuring the board in multiple stages, the area required for installing the board can be reduced, improving mountability to various control objects and providing a board mounting structure with excellent heat resistance and durability.

Furthermore, the relay terminal of this configuration is rod-shaped, and when attaching, for example, a straight-shaped relay terminal to the spacer substrate, it is only necessary to insert it into a hole previously provided in the spacer substrate, making it extremely easy to manufacture the spacer substrate.
In addition, by providing a ground terminal on the first or second board as in this configuration, the influence of noise from devices in the vicinity of the control board can be reduced. With this configuration, the grounding work can be performed at the same time as mounting the first or second board to various devices, so a board mounting structure with excellent mounting workability and high reliability can be obtained.
In addition to the above effects, with this configuration, simply by attaching the frame member that holds the first board and the like to the housing, the heat dissipation section on the board comes into contact with the heat dissipation sheet on the housing side. At that time, the pressing section of the frame member abuts against the board, generating a reaction force, ensuring contact between the heat dissipation section of the board and the heat dissipation sheet of the housing. Also, with this configuration, simply by pressing the heat dissipation section against the heat dissipation sheet, thermal expansion of the board along the planar direction of the board can be tolerated. Therefore, unexpected stress is not generated in the board, and damage to the soldered parts can be effectively prevented.

In the substrate mounting structure of the present invention, the partition can be configured as a slit.

(effect)
If the partitions are slits, the transmission of stress between the regions can be substantially eliminated. Moreover, although the spacer substrate is often made of synthetic resin, providing slits does not require complicated processing. Therefore, the partitions between the regions can be constructed in an extremely rational manner.

In the substrate mounting structure according to the present invention, a first fitting portion can be provided between the spacer substrate and the first substrate to position them relative to each other, and a second fitting portion can be provided between the spacer substrate and the second substrate to position them relative to each other.

(effect)
The provision of such a fitting portion makes it easier to connect the relay terminal to the first board or the second board, and improves the efficiency of the assembly work of multiple boards, thereby providing a low-cost board mounting structure.

In the substrate mounting structure according to the present invention, the first substrate can be a control substrate, the second substrate can be a power supply substrate, and the heat dissipation unit can be provided on the second substrate.

(effect)
In this configuration, the necessary boards are divided into control boards and power boards, and the heat dissipation section is provided on the power board, which allows for effective removal of heat. In addition, because the boards are divided according to the level of heat generation, damage to soldered parts caused by heat, particularly on the control board, can be more effectively prevented.

In the substrate mounting structure according to the present invention,
The electronic component mounting device includes a first substrate and a second substrate on which electronic components are mounted, and a spacer substrate provided between the first substrate and the second substrate;
the spacer substrate includes a plurality of regions provided via partitions such that a relative distance between the regions changes based on an external force acting along a planar direction of the spacer substrate;
rod-shaped relay terminals that electrically connect the soldered portions of the first board and the soldered portions of the second board are distributed and disposed in a penetrating state in each of the plurality of regions,
a ground terminal for the first substrate or the second substrate is provided on at least one of a first fixing portion of the first substrate fixed to a housing and a second fixing portion of the second substrate fixed to the housing;
The housing may include a frame member that integrally attaches the first substrate, the second substrate, and the spacer substrate, and a cover member that covers one side of the frame member, and when the frame member and the cover member are attached to the housing, annular sealing members are disposed between the peripheral edge of the one side of the frame member and the peripheral edge of the cover member, and between the peripheral edge of the other side of the frame member and the housing.

(effect)
With this configuration, the work of mounting the first and second substrates and the spacer substrate to the housing is simplified. Also, since the seal members are disposed on the front and back surfaces of the frame member, a substrate mounting structure with excellent dust-proof and waterproof properties can be obtained.

FIG. 1 is an explanatory diagram showing an example of use of a displacement detection device according to an embodiment of the present invention; An explanatory diagram showing the configuration of a drive unit FIG. 3 is an exploded perspective view showing the configuration of a drive unit. FIG. 1 is a cross-sectional side view showing a configuration of a displacement detection device. FIG. 2 is a perspective view showing a configuration of a main part of a displacement detection device; FIG. 1 is a vertical cross-sectional view showing a configuration of a main part of a displacement detection device. FIG. 3 is a perspective view showing the configuration of a control unit. FIG. 1 is a perspective view showing a configuration of a spacer substrate; FIG. 1 is a perspective view showing a fitting structure of a first substrate and a second substrate; An explanatory diagram showing the grounding structure of the control unit. An explanatory diagram showing the heat dissipation structure of the control unit. An explanatory diagram showing the sealing structure of the control unit.

(overview)
The displacement detection device S according to the present invention can be used, for example, in a linear motion mechanism provided in a rear wheel steering device of a vehicle.
In the linear motion mechanism, for example, a cylindrical nut 2 is rotated by an electric motor 1, which is a drive unit M, to reciprocate a rod 3 screwed into the nut 2. A sliding surface that comes into contact with the inner surface of a housing 4 of the linear motion mechanism is formed on a part of the rod 3, and the rod 3 is configured to reciprocate without rotating.

Figures 1 and 2 show the configuration of the linear motion mechanism according to this embodiment. The linear motion mechanism includes a control unit C provided on the left side of Figure 1 and a drive unit M provided on the right side. The control unit C has a linear motion sensor 25 that measures the displacement state of the rod 3, and calculates the position of the rod 3 based on a signal from this linear motion sensor 25. Based on the calculation result, the control unit C supplies a drive signal to the drive unit M to move the rod 3 to the desired position.

(Drive unit)
2 and 3, the driving unit M of this embodiment includes a stator 5 having an axis X along the moving direction of the linear motion mechanism, and a cylindrical rotor 6 that rotates inside the stator 5. A rod 3 is inserted inside the cylindrical rotor 6. The rotor 6 is supported on both sides of the housing 4 by rotor bearings 7 on both outside sides along the axis X, sandwiching the opposing position of the stator 5.

(Planetary gear mechanism)
A planetary gear mechanism P is connected to one end of the rotor 6. Specifically, a sun gear P1 is formed on the outer surface of the end of the rotor 6. Three planetary gears P2 mesh with the sun gear P1, and a ring gear P3 fixed to the housing 4 meshes with the outer side of the planetary gear P2.

The carrier K of the planetary gear P2 is screwed and fixed to the outer periphery of the nut 2 which screws onto the rod 3. The carrier K has a first carrier K1 which is fixed to the outer surface of the nut 2, and a second carrier K2 which is fitted and fixed to the outside of the first carrier K1. Three shaft members 8 which respectively support the three planetary gears P2 are fixed to the second carrier K2.

The nut 2 is cylindrical, and has a female trapezoidal thread 9a formed on its inner surface as the output gear 9 of the drive unit M. On the other hand, the rod 3 has a male trapezoidal thread 10a formed on its outer surface as the threaded portion 10. The nut 2 is made of brass to provide wear resistance. The rod 3 moves back and forth without rotating relative to the housing 4 by abutting the sliding member 21 (described below) against the inner surface of the housing 4. A bearing portion 11 using a thrust bearing is fitted onto the outer surface of the nut 2, and this bearing portion 11 is fitted inside the inner surface of the housing 4.

The first carrier K1 is fitted onto one end of the nut 2 and screwed into place via the fixing screw 12. The other end of the nut 2 is formed with a radially protruding bulge 2a, which clamps the inner member 11a of the bearing 11 along the axis X between the bulge 2a and the end face of the first carrier K1. With this configuration, the bearing 11 and the first carrier K1 can be easily fixed to the nut 2, making the assembly process more efficient.

The second carrier K2, which holds the planetary gear P2, is fitted and fixed further outward from the first carrier K1. This fitting and fixing is performed using two types of fitting parts. One is a cylindrical first fitting part Ka formed on the rear side in the fitting direction along the axis X when viewed from the second carrier K2 side. This is formed by a cylindrical fitting outer surface formed on the outer surface of the first carrier K1 and a cylindrical fitting inner surface formed on the inner surface of the second carrier K2. The other is a spline-shaped second fitting part Kb that is adjacent to the first fitting part Ka and fits on the front side in the fitting direction when viewed from the second carrier K2 side.

The second fitting portion Kb is configured, for example, in a star-shaped cross section perpendicular to the axis X. This prevents the first carrier K1 and the second carrier K2 from rotating relative to each other, making it possible to configure a durable carrier K. Furthermore, when the first carrier K1 is screwed into the nut 2, the second fitting portion Kb can be used as an engagement portion for a fastening tool. The first carrier K1 and the second carrier K2 are formed from steel instead of the conventional brass, which reduces weight and costs.

In this embodiment, the housing 4 has a particularly narrow shape, and the bearing portion 11 needs to be located at the back of the carrier K. Therefore, the installation sequence is as follows: the bearing portion 11 is attached to the nut 2, the bearing portion 11 is clamped by the first carrier K1, and then these are fixed to the housing 4. The second carrier K2 is then attached to the first carrier K1.

The bearing 11 is fixed using a circular spacer 13 that abuts against the outer member 11b of the bearing 11, and a retaining ring 14 that abuts against the spacer 13 to hold the bearing 11 and the spacer 13 in place. The retaining ring 14 is, for example, a C-shaped snap ring that fits into a groove 15 formed on the inner surface of the housing 4.

With this configuration, the spacer 13 can be attached before the second carrier K2 is attached, and the dimensions of the spacer 13 can be set regardless of the dimensions of the second carrier K2, which tends to be relatively large. This increases the degree of freedom in designing the mounting portion of the bearing portion 11, and improves the efficiency of the mounting work of the bearing portion 11. Furthermore, the size of the bearing portion 11 and the size of the second carrier K2 can be set separately, which increases the degree of freedom in setting the components of the planetary gear mechanism P.

Even if there is an error in the position where the groove portion 15 is formed, by using a spacer 13 of an appropriate thickness, the outer member 11b can be fixed to the housing 4 without rattling. In addition, by making the spacer 13 a completely annular member, the spacer 13 abuts against the entire circumference of the outer member 11b, improving the effect of preventing the outer member 11b from coming loose.

After the bearing portion 11 has been fixed, the second carrier K2 is fitted and fixed to the first carrier K1. The planetary gear P2 may be attached to the second carrier K2 either before or after the second carrier K2 is attached to the first carrier K1. The ring gear P3 is fitted to the inner surface of the housing 4 as shown in FIG. 2.

(Guide section)
When the rod 3 is reciprocated by the driving unit M, the rotation of the rod 3 is prevented by the housing 4. For that purpose, as shown in Figures 4 to 6, a guide unit G is formed across the rod 3 and the housing 4 on the side of the rod 3 opposite the threaded unit 10.

The guide section G is composed of a slider 20 provided on the rod 3, a sliding member 21 attached to the slider 20, and a guide surface 22 provided on the housing 4 so that the sliding member 21 slides over a predetermined distance.

The slider 20 is a member having a U-shaped cross section perpendicular to the axis X as shown in Figures 5(a) and (b). The slider 20 is fixed to the rod 3 by a mounting bolt, which is a fastening member 23, through a mounting hole 20b provided in the bottom 20a forming the U-shape. The mounting procedure involves inserting the rod 3 into the housing 4, and aligning the slider mounting position of the rod 3 with the positions of the opposing guide surfaces 22 formed in the opening of the housing 4. In this state, the slider 20, to which the sliding member 21 has already been attached, is positioned and fastened by the fastening member 23.

The sliding member 21 is attached to the slider 20 by inserting a groove-shaped insertion portion 21a formed on the sliding member 21 into a pair of protrusions 20c that form a U-shape on the slider 20. A claw portion is formed as an engagement portion 21c on the inner wall 21b that forms the insertion portion 21a of the sliding member 21, and the claw portion is engaged with a hole provided as an engaged portion 20d on the pair of protrusions 20c. By engaging in this way using a so-called snap fit, the installation work of the sliding member 21 to the slider 20 is simplified and the work costs can be reduced.

The tip edge of each protrusion 20c is formed with a step 20e, with both ends cut along the direction of the axis X. As a result, when the insertion portion 21a of the sliding member 21 is inserted into the protrusion 20c, as shown in FIG. 5(a), the tip edge except for the step 20e is exposed on the upper surface of the sliding member 21, preventing the sliding member 21 from rattling along the direction of the axis X relative to the protrusion 20c.

The outward surface of each of the pair of sliding members 21 serves as sliding surface 21d, which comes into sliding contact with guide surface 22 provided on housing 4 to prevent rotation of rod 3. To ensure that this rotation prevention is performed, the outward surfaces of the pair of protruding portions 20c of slider 20 are formed as planar receiving surfaces 20f, which come into face-to-face contact with flat surface 21e formed on the inside of insertion portion 21a of sliding member 21. By providing such receiving surfaces 20f and flat surface 21e, the rotation restriction function of rod 3 is reliably exerted, enabling the linear motion mechanism to have a high torque.

The slider 20 is made of a metal material such as steel or stainless steel, and can reliably receive the torque that prevents the rod 3 from rotating as a reaction force from the guide surface 22 when the rod 3 moves back and forth. On the other hand, the sliding member 21 is made of a material with a low coefficient of friction, such as fluororesin.

In addition, by separating the slider 20 and the sliding contact member 21, the sliding contact member 21 can be attached to the slider 20 after the slider 20 is attached to the rod 3. If the sliding contact member 21 is attached before the slider 20 is attached, the fastening member 23 can be easily fixed between the pair of protruding portions 20c. With this configuration, there is no need to change the position of the rod 3, such as by inverting it, when assembling the slider 20, and efficient assembly work can be performed.

(Control Unit)
The position of the rod 3 is detected by the control unit C. This detection is performed by a magnet 24 provided between the pair of sliding contact members 21 and a linear motion sensor 25 provided on a control board 26 in a state in close proximity to and facing the magnet 24.

As shown in FIG. 5, the magnet 24 is formed by inserting a long piece of resin material into the magnet block 24a. The magnet block 24a is fixed to the rod 3, but is attached so that an external force that would prevent the rod 3 from rotating is not input from the sliding member 21 to the magnet 24.

Specifically, as shown in FIG. 5(b), the magnet block 24a is inserted between a pair of sliding members 21, and the back surface of the magnet block 24a is positioned in a state in which it abuts against the first seats 20g at two locations formed on the bottom 20a of the slider 20. This places the detection surface of the magnet 24 at a predetermined height relative to the surface of the rod 3.

In addition, protrusions 24b are provided near both ends of the magnet block 24a, and second seats 24c formed on these protrusions 24b sandwich each of the two sliding contact members 21 in the direction along the axis X. At this time, if the second seats 24c are made to lightly abut against the sliding contact members 21, the magnet block 24a will not rattle when the rod 3 moves back and forth, and the position measurement accuracy of the rod 3 will be further improved.

Furthermore, the positioning of the magnet 24 in the width direction, i.e., the direction intersecting the axis X when viewed in a direction perpendicular to the surface of the magnet 24, is performed by the housing 4. In other words, a second guide surface 27 provided in the housing 4 near and parallel to the guide surface 22 slides against the protruding portion 24b, thereby positioning the magnet 24 and guiding its movement.

In this way, after the slider 20 and the sliding member 21 are fixed to the rod 3 inserted into the housing 4, the magnet block 24a is positioned relative to the sliding member 21 and the housing 4, allowing the magnet 24 to be easily installed relative to the rod 3.

With this configuration, the force preventing the rotation of the rod 3 during reciprocating movement of the rod 3 does not act on the magnet 24 from the sliding contact member 21. This eliminates the risk of the magnet 24 being damaged, and makes it possible to obtain a displacement detection device S with a rational structure and enhanced durability.

Figures 4 and 7 show the configuration of the control unit C. The magnet 24 constituting the control unit C is fixed to the side of the rod 3 and is arranged with its detection surface facing upward. A linear motion sensor 25 is arranged facing this magnet in close proximity. The linear motion sensor 25 is mounted on a first board 26a (described below) and detects the position information of the rod 3. Based on the signal obtained by the linear motion sensor 25, the control unit C calculates the position of the rod 3 and transmits a drive signal to the drive unit M to move the rod 3 to the desired position.

As shown in Figs. 7(a) and (b), the control unit C includes, for example, a first board 26a and a second board 26b as the control board 26. The first board 26a is the board facing the magnet 24, and is a so-called control system board provided with the linear sensor 25 and the like. The second board 26b is a so-called power system board provided with a power supply circuit and the like.

In this embodiment, a spacer substrate 26c having an annular shape with an overall rectangular shape is provided between the first substrate 26a and the second substrate 26b, and electrically connects the first substrate 26a and the second substrate 26b. The first substrate 26a, the second substrate 26b, and the spacer substrate 26c are attached to a frame member 38 before being fixed to the housing 4. The frame member 38 is provided with a connector 38a that connects the first substrate 26a and the like to the vehicle's ECU. By stacking multiple substrates in this manner, the overall planar area of the control unit C can be reduced, and the mountability to target equipment such as a linear motion mechanism can be improved.

As shown in FIG. 8, the spacer substrate 26c is provided with a plurality of relay terminals 30 that connect the soldered portions of the first substrate 26a and the soldered portions of the second substrate 26b. Here, the relay terminals 30 are configured in the shape of straight rods. The relay terminals 30 are made of a material that has excellent mechanical strength, electrical conductivity, thermal conductivity, and corrosion resistance, such as a Cu alloy material or an Fe alloy material.

Each relay terminal 30 is disposed so as to penetrate the spacer substrate 26c. For example, multiple holes are formed in the spacer substrate 26c beforehand, and the relay terminals 30 are inserted and fitted into the holes. Alternatively, the spacer substrate 26c can be insert molded with the relay terminals 30 embedded in predetermined positions.

To connect the first board 26a and the second board 26b to each relay terminal 30, it is necessary to accurately position the first board 26a and the second board 26b with respect to all relay terminals 30. For this reason, as shown in FIG. 9, a first positioning portion 31 is provided between the spacer board 26c and the first board 26a to position them relative to each other.

For example, a first convex member 31a that protrudes toward the first substrate 26a is provided on the spacer substrate 26c, and is fitted into a first fitting hole 31b provided in the first substrate 26a. On the other hand, it is also preferable to provide a second convex member 32a provided on the spacer substrate 26c and a second fitting hole 32b provided on the second substrate 26b as the second positioning portion 32 for the spacer substrate 26c and the second substrate 26b.

By providing such a first positioning portion 31 and a second positioning portion 32, the work of connecting the spacer substrate 26c to the first substrate 26a and the second substrate 26b becomes easier, and the work of assembling substrates in multiple stages becomes more efficient. Therefore, a low-cost substrate mounting structure can be obtained.

(Heat-resistant structure)
A large number of electronic components are mounted on the first board 26a and the second board 26b, and various amounts of heat are generated during normal use. This heat can cause changes in the dimensions of each board, and the mechanical properties of the heated soldered parts can change. As a result, the relative positions of the soldered parts of the first board 26a and the soldered parts of the second board 26b are displaced along the planar direction of the boards, causing problems such as cracking of the soldered parts.

Therefore, in the spacer substrate 26c of this embodiment, slits 33a are provided as partitions 33 that separate the areas A in which a predetermined number of relay terminals 30 are arranged. Specifically, as shown in FIG. 8, multiple slits 33a extending perpendicularly to the periphery of the spacer substrate 26c are formed for each area A of a predetermined area. To achieve this, only the portions of the slits 33a are protruded toward the center of the spacer substrate 26c, and the slits 33a are formed inside this protruding portion 34. This ensures the connection rigidity between the areas A on both sides of the slits 33a.

This configuration allows the spacer substrate 26c to move relative to the predetermined regions A, absorbing changes in the position of the relay terminal 30 as the temperature of the first substrate 26a and the second substrate 26b rises. As a result, excessive bending forces are not applied to the soldered portions of the first substrate 26a and the second substrate 26b, and the soldered portions can be effectively protected.

(Grounding structure)
In the board mounting structure of this embodiment, the first board 26a and the second board 26b are provided with the following grounding structure to suppress the generation of noise. That is, a ground terminal 36 is provided for at least one of the first fixing portion 35a used for fixing the first board 26a to the housing 4 and the second fixing portion 35b used for fixing the second board 26b to the housing 4.

This ground terminal 36 grounds the second board 26b, etc. to the frame member 38 by attaching the second board 26b, etc. to the frame member 38. Furthermore, the frame member 38 is fixed to the housing 4 using a screw member 39, etc., so that the second board 26b, etc. is grounded to the housing 4.

Specifically, as shown in Figures 10(a) and 10(b), a ground terminal 36 formed by bending a metal plate is attached to a fixing screw 37 that fixes the second board 26b to a frame member 38, for example. This ground terminal 36 is in contact with the ground circuit of the second board 26b. One side of the ground terminal 36 is provided with an elastic portion 36a that protrudes away from the fixing screw 37. This elastic portion 36a protrudes outward from the second board 26b, and is configured so that the second board 26b and the housing 4 are electrically connected simply by attaching the frame member 38 having the second board 26b to the housing 4.

This configuration can reduce the effects of noise on the first board 26a and the second board 26b from nearby devices. In addition, when attaching the first board 26a and the second board 26b to various devices, grounding work can be performed at the same time, resulting in a highly reliable board mounting structure with excellent attachment workability.

(heat dissipation structure)
The first board 26a and the second board 26b of this configuration generate heat during use. In particular, the amount of heat generated by the second board 26b, which is a power supply board, is greater than that of the first board 26a. If the amount of heat generated becomes excessive, the mounted components and soldered parts of the second board 26b may be damaged. Therefore, the board mounting structure of this configuration is provided with the following heat dissipation structure.

As shown in FIG. 11, a pressing portion 40 is formed on a portion of the frame member 38, for example, to press a portion of the second board 26b toward the housing 4. A heat dissipation portion 41 is formed on the back surface of the portion of the second board 26b that faces the pressing portion 40, and when the second board 26b etc. is attached to the housing 4, this heat dissipation portion 41 abuts against a heat dissipation sheet 42 provided on the housing 4. In other words, the pressing portion 40 is configured to press the back surface of the second board 26b so that the heat dissipation portion 41 abuts against the heat dissipation sheet 42 reliably at this time.

With this configuration, simply by attaching the frame member 38, which already holds the second board 26b, etc., to the housing 4, the heat dissipation section 41 provided on the second board 26b is reliably pressed against the heat dissipation sheet 42 of the housing 4, and a good heat dissipation effect can be obtained.

As in this configuration, the necessary control boards 26 are divided into the first board 26a of the control system and the second board 26b of the power supply system, and the heat dissipation section 41 is provided on the second board 26b, thereby enhancing the effect of removing heat. In addition, because the control boards 26 are divided according to the level of heat generation, damage to soldered parts caused by heat, particularly on the second board 26b of the power supply system, can be more effectively prevented.

Furthermore, the pressing portion 40 of this configuration only presses the heat dissipation portion 41 against the heat dissipation sheet 42, and does not restrict the thermal expansion of the second substrate 26b, etc. along its planar direction. Therefore, unexpected stress is not generated in the second substrate 26b, and damage to the soldered portions can be effectively prevented.

(Seal structure)
The first substrate 26a, the second substrate 26b and the spacer substrate 26c are fixed to the housing 4 in a state where they are attached to one side of a frame member 38, and further, the opposite side of the frame member 38 is covered with a cover member 43. When the frame member 38 and the cover member 43 are attached to the housing 4, annular seal members 44 are disposed between the peripheral edge of one side of the frame member 38 and the housing 4, and between the peripheral edge of the other side of the frame member 38 and the peripheral edge of the cover member 43.

This seal member 44 is made of, for example, various rubber members with a circular cross-sectional shape, and has a planar shape that corresponds to the peripheral shape of the frame member 38. At least one of the frame member 38, cover member 43, and housing 4 that are arranged opposite each other has a fixing groove 45 formed therein into which the seal member 44 fits.

This makes it difficult for the seal member 44 to shift position when attaching the frame member 38 and the cover member 43, making the attachment work easier. In addition, the seal member 44 is prevented from shifting position after attachment, making it possible to obtain a board mounting structure that has excellent dust-proofing and waterproofing properties for a long period of time.

The substrate mounting structure of the present invention connects a first substrate and a second substrate on which electronic components are mounted using a plurality of rod-shaped relay terminals, and can be widely used in cases where a spacer substrate having a plurality of relay terminals is placed between the first substrate and the second substrate.

26a First substrate 26b Second substrate 26c Spacer substrate 30 Relay terminal 31 First fitting portion 32 Second fitting portion 33 Partition portion 33a Slit 35a First fixing portion 35b Second fixing portion 36 Ground terminal 38 Frame member 40 Pressing portion 41 Heat dissipation portion 42 Heat dissipation sheet 43 Cover member 44 Seal member A Region

Claims (5)

The electronic component mounting device includes a first substrate and a second substrate on which electronic components are mounted, and a spacer substrate provided between the first substrate and the second substrate;
the spacer substrate includes a plurality of regions provided via partitions such that a relative distance between the regions changes based on an external force acting along a planar direction of the spacer substrate;
rod-shaped relay terminals that electrically connect the soldered portions of the first board and the soldered portions of the second board are distributed and disposed in a penetrating state in each of the plurality of regions,
a ground terminal for the first substrate or the second substrate is provided on at least one of a first fixing portion of the first substrate fixed to a housing and a second fixing portion of the second substrate fixed to the housing;
a frame member that is attached to the housing while holding the first substrate, the second substrate, and the spacer substrate together in advance,
a pressing portion for pressing a portion of the first board or the second board toward the housing on a portion of the frame member;
a heat dissipation portion is formed on a surface of the first substrate or the second substrate opposite to the pressing portion, the surface being opposed to the pressing portion;
A board mounting structure in which a heat dissipation sheet is disposed on the housing side so as to abut against the heat dissipation portion when the frame member is attached. The electronic component mounting device includes a first substrate and a second substrate on which electronic components are mounted, and a spacer substrate provided between the first substrate and the second substrate;
the spacer substrate includes a plurality of regions provided via partitions such that a relative distance between the regions changes based on an external force acting along a planar direction of the spacer substrate;
rod-shaped relay terminals that electrically connect the soldered portions of the first board and the soldered portions of the second board are distributed and disposed in a penetrating state in each of the plurality of regions;
a ground terminal for the first substrate or the second substrate is provided on at least one of a first fixing portion of the first substrate fixed to a housing and a second fixing portion of the second substrate fixed to the housing;
A substrate mounting structure comprising a frame member for integrally mounting the first substrate, the second substrate, and the spacer substrate, and a cover member for covering one side of the frame member, wherein, when the frame member and the cover member are attached to the housing, annular sealing members are disposed between a peripheral portion of the one side of the frame member and a peripheral portion of the cover member, and between a peripheral portion of the other side of the frame member and the housing. 3. The substrate mounting structure according to claim 1 , wherein the partition is a slit. A substrate mounting structure as described in any one of claims 1 to 3, wherein a first mating portion for positioning the spacer substrate and the first substrate is provided between the spacer substrate and the second substrate, and a second mating portion for positioning the spacer substrate and the second substrate is provided between the spacer substrate and the second substrate. the first board is a control board, and the second board is a power supply board,
The substrate mounting structure according to claim 1 , wherein the heat dissipation portion is provided on the second substrate.