Electronic apparatus

Abstract

To provide an electronic apparatus that is easy to manufacture and can reduce manufacturing costs.SOLUTION: An electronic apparatus 1 includes a substrate 2 having a substrate main body 21 with fixing holes 22 and terminals 23 one end of which is fixed to the substrate main body 21, a metal heat sink 3 having a main body portion 31 facing the substrate 2, terminal insertion holes 32 provided in the main body portion 31 to allow the terminals 23 to pass through, and a spacer 33 rising from the main body portion 31 and having screw holes 33a facing the fixing holes 22 in the substrate 2, a cylindrical connector 4 made of synthetic resin that is inserted into the terminal insertion holes 32 of the heat sink 3 to accommodate the terminals 23 therein and has a step portion 42 on its outer periphery that faces the main body portion 31 of the heat sink 3, and a retaining plate 5 that is fixed to the spacer 33 together with the substrate 2 by screws 60 that are screwed into the spacer 33 and that abuts against the connector 4 to secure the connector 4 to the heat sink 3.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to an electronic device. [Background technology]

[0002] Electronic devices are used, for example, in motors, and are configured with a board on which a drive circuit for driving the motor, a microcontroller for controlling the motor, and terminals for connecting to external devices such as an external power supply are mounted, a metal heat sink for holding the board and dissipating heat from the components mounted on the board, and a synthetic resin connector that is attached to the heat sink and surrounds the terminals to keep them connected to the wiring on the external device (see, for example, Patent Document 1).

[0003] In conventional electronic devices configured in this manner, spacers with screw holes for attaching substrates are provided in multiple locations on the front side of the heat sink.The substrate is first placed on the tip surface of the spacer, and the fixing holes in the substrate are aligned with the screw holes, and screws are attached to the screw holes to fix the substrate to the heat sink.

[0004] Next, the heat sink is turned over and a cylindrical connector is fixed to the backside of the heat sink with screws to complete the electronic device. In the completed electronic device, the terminals protrude into the connector through the terminal insertion holes in the heat sink, and when the connector is joined to the connector on the external power supply side, the terminals remain connected to the wiring on the external device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6496794 Summary of the Invention [Problem to be solved by the invention]

[0006] As mentioned above, the manufacturing of conventional electronic devices involves two steps: fixing a substrate to the front side of a heat sink with screws, and fixing a connector to the back side of the heat sink with screws. This involves many steps and requires many screws to be tightened, making the manufacturing process complicated and time-consuming.

[0007] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide an electronic device that is easy to manufacture and can reduce manufacturing costs. [Means for solving the problem]

[0008] In order to solve the above-mentioned problems, the electronic device of the present invention comprises a metal heat sink having a substrate main body with a fixing hole, a substrate having a terminal one end of which is fixed to the substrate main body, a main body portion facing the substrate, a terminal insertion hole provided in the main body portion to allow the terminal to be inserted therethrough, and a spacer rising from the main body portion and having a screw hole facing the fixing hole in the substrate, a cylindrical resin connector that is inserted into the terminal insertion hole of the heat sink to accommodate the terminal inside and has a step on its outer periphery that faces the main body portion of the heat sink, and a retaining plate that is fixed to the spacer together with the substrate by a screw that is screwed into the spacer and that abuts against the connector to secure the connector to the heat sink.

[0009] With an electronic device configured in this manner, when fixing a connector to a heat sink, the tip of the connector is fitted into the terminal insertion hole of the heat sink to temporarily assemble the connector to the heat sink, and then, without turning the heat sink over, the board and pressure plate are placed on the spacer, and the screws that secure the board to the spacer are used to secure the connector to the heat sink together with the board and pressure plate.

[0010] In addition, the electronic device may be provided with a seal ring that is elastic and interposed between the main body and the step portion of the connector, and is compressed by receiving a load from the pressure plate through the connector, and the axial length from the step portion of the connector to the abutment surface that abuts against the pressure plate may be shorter than the length from the surface facing the step portion of the main body to the abutment surface on the pressure plate that abuts against the connector.

[0011] With an electronic device configured in this manner, when the pressure plate is fixed to the spacer, the connector is clamped between the seal ring and the pressure plate, and the board abuts against the tip surface of the spacer without floating up, being fixed to the heat sink without any play.In addition, the seal ring is always compressed by the connector, and a resilient force is applied to the connector, urging it toward the pressure plate.Even if dimensional errors occur in the length from the step in the connector to the surface abutting the pressure plate, or in the length from the main body of the heat sink to the pressure plate, the error is absorbed by the seal ring, and the connector can be reliably fixed to the heat sink.

[0012] Furthermore, in the electronic device, the board may have a connector fixing hole, and the retaining plate may be disposed on the opposite side of the board from the heat sink and abut against the connector through the connector fixing hole. With this configuration, it is easy to position the retaining plate in an appropriate position while visually checking the position of the connector, thereby improving workability.

[0013] The electronic device may also be configured such that the retaining plate is disposed on the heat sink side of the board. With such a configuration, errors in the vertical length of the board body do not affect the position of the retaining plate, making it easier to manage dimensions.

[0014] Furthermore, the connector in the electronic device may have a pin that is inserted into the connector fixing hole, and the retaining plate may abut against the pin. With this electronic device configured in this way, inserting the connector pin into the connector fixing hole in the board makes it easy to align the retaining plate and the connector, thereby further improving workability. [Effects of the Invention]

[0015] According to the electronic device of the present invention, manufacturing is easy and manufacturing costs can be reduced. [Brief explanation of the drawings]

[0016] [Figure 1]1 is a longitudinal sectional view of a motor to which an electronic device according to an embodiment of the present invention is applied; [Figure 2] FIG. 2 is a plan view of a substrate in the electronic device of the present embodiment. [Figure 3] FIG. 2 is a plan view of a heat sink in the electronic device of the present embodiment. [Figure 4] 1 is a partially enlarged vertical cross-sectional view of an electronic device according to an embodiment of the present invention. [Figure 5] FIG. 10 is a partial enlarged vertical cross-sectional view of an electronic device according to a modified example of the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0017] The present invention will be described based on the embodiment shown in the drawings. As shown in Figures 1 to 4, electronic device 1 in this embodiment includes substrate 2, heat sink 3 that holds substrate 2, connector 4, and retaining plate 5, and is applied to motor M to be used as a driver that drives motor M.

[0018] The following provides a detailed description of each component of the electronic device 1. The motor M to which the electronic device 1 is applied includes a cylindrical case 10, a cylindrical stator 11 fixed to the inner periphery of the case 10, a rotor 12 rotatable relative to the case 10 and disposed within the stator 11, and the electronic device 1, as shown in FIG.

[0019] Case 10 is cylindrical with a bottom, including bottom 10a and cylindrical portion 10b rising from the outer periphery of bottom 10a, and is provided with hole 10c in bottom 10a and mounting pieces (not shown) on the outer periphery of bottom 10a that enable motor M to be mounted to an external device. A ball bearing 13 is mounted on the inner periphery of bottom 10a of case 10 and accommodated in hole 10c. Stator 11 is cylindrical and includes stator core 11a made of a cylindrical soft magnetic material and having multiple teeth 11b on its inner periphery, and windings 11c wound around teeth 11b.

[0020] The heat sink 3 in the electronic device 1 is attached to the upper end of the cylindrical portion 10b of the case 10, and has an annular bearing holding portion 35 at a position axially opposite the hole 10c in the bottom portion 10a, and a ball bearing 14 is attached to the inner circumference of the bearing holding portion 35.

[0021] Rotor 12 is inserted into the inner periphery of ball bearing 13 attached to case 10 and ball bearing 14 attached to heat sink 3. Rotor 12 includes shaft 12a, cylindrical yoke 12b attached to the outer periphery of shaft 12a, and a plurality of permanent magnets 12c attached to the outer periphery of yoke 12b. Rotor 12 configured in this manner is inserted into the inner periphery of stator 11, with both ends of shaft 12a held by ball bearings 13 and 14, respectively. Thus, rotor 12 is rotatably held by case 10 and heat sink 3, and can rotate freely within stator 11.

[0022] Furthermore, a substrate 2 is disposed on the side of the heat sink 3 opposite the stator, and the substrate 2 is covered and protected by a box-shaped cover 15 attached to the side of the heat sink 3 opposite the stator.

[0023] Next, a detailed description will be given of each part of the electronic device 1. As shown in Figures 1 and 2, in this embodiment, the board 2 includes a rectangular board main body 21, a plurality of terminals 23 having one end fixed to the board main body 21, and a plurality of electronic components 24 mounted on the board main body 21 and constituting a drive circuit, a controller for controlling the motor M, a sensor for detecting the rotational position of the rotor 12, etc.

[0024] 2, the board body 21 is provided with fixing holes 22 penetrating the wall thickness at each of the four corners and near the center, and connector fixing holes 25 are provided between the fixing holes 22, 22 in close proximity to the fixing holes 22 at the two lower corners in FIG. 2. Thus, in this embodiment, two connector fixing holes 25 are provided, one inside each of the two fixing holes 22 on the lower side of the board body 21 in FIG. 2.

[0025] 2, rectangular retaining plates 5 are attached to the two lower corners of the board body 21, each of which overlaps the connector fixing hole 25 and has insertion holes 5a facing the fixing holes 22. In other words, each retaining plate 5 is attached to the board body 21 so as to be parallel to the lower side of the board body 21, and closes the upper end of the connector fixing hole 25 in FIG.

[0026] The retaining plate 5 is made of metal and has high flexural rigidity. The inner diameter of the insertion hole 5a in the retaining plate 5 is approximately equal to the inner diameter of the fixing hole 22 in the substrate main body 21, and the insertion hole 5a and the fixing hole 22 allow the insertion of a screw 60 for fixing the substrate 2 to the heat sink 3, which will be described later. Although the retaining plate 5 is attached to the substrate main body 21, it does not have to be attached to the substrate main body 21.

[0027] 1 and 4, the terminals 23 extend downward in FIG. 1 from the board body 21 and are connectable to power supply terminals attached to the ends of wires connected to an external power supply (not shown). The number of terminals 23 required by the specifications is provided on the board body 21, including terminals for connecting to external power supplies as well as for connecting to signal lines. The terminals 23 are arranged side by side on the lower side of the board body 21 in FIG. 2. The installation locations and arrangement of the terminals 23 within the installation locations can be freely changed, but they are arranged so as to be accommodated within the connector 4, which will be described later.

[0028] 1, 3, and 4, the heat sink 3 is made of aluminum and includes a rectangular, plate-like main body 31 facing the substrate 2, terminal insertion holes 32 that penetrate the main body 31 in the vertical direction in FIG. 1 and allow the insertion of terminals 23, cylindrical spacers 33 that rise from the four corners and near the center of the main body 31 toward the opposite side from the stator and on whose tips the substrate 2 is placed, a cylindrical fitting portion 34 that protrudes downward in FIG. 1 from the stator side of the main body 31 and fits into the inner periphery of the open end of the cylindrical portion 10b of the case 10, and a cylindrical bearing holder 35 that extends downward inside the fitting portion 34 of the main body 31 and has a ball bearing 14 attached to its inner periphery. Although the heat sink 3 is made of aluminum in this embodiment, copper, which has high thermal conductivity, may also be used.

[0029] When the fitting portion 34 of the heat sink 3 is fitted into the cylindrical portion 10b of the case 10, the open end of the cylindrical portion 10b is closed and a seal ring 34a attached to the outer periphery of the fitting portion 34 is brought into close contact with the inner periphery of the cylindrical portion 10b, thereby sealing the space between the case 10. When the fitting portion 34 of the heat sink 3 is fitted into the cylindrical portion 10b of the case 10, the bearing holding portion 35 faces the hole 10c of the case 10 in the axial direction, and the rotor 12 is positioned at the axial center of the case 10.

[0030] As described above, the main body 31 is rectangular and plate-shaped, and is provided around the periphery on the side opposite the stator with an annular groove 31a that accommodates the packing 17 that is in close contact with the cover 15 and the main body 31, and an annular seal groove 31b that surrounds the periphery of the terminal insertion hole 32 and accommodates the seal ring 6. Although not specifically shown, the main body 31 is provided with busbar insertion holes, and a busbar (not shown) that is connected to the winding 11c of the stator 11 is connected to the drive circuit on the substrate 2 through the busbar insertion hole. Thus, the electronic components 24 mounted on the substrate 2 that constitute the drive circuit are connected to the winding 11c via the busbar, and the motor M can be driven by applying electricity to the winding 11c from an external power source via the substrate 2.

[0031] 3, the terminal insertion holes 32 are open on the lower side of the main body 31 so as to allow insertion of all of the terminals 23 of the substrate 2. Specifically, in this embodiment, the terminal insertion holes 32 are oval and penetrate the thickness of the main body 31 to allow insertion of the terminals 23. Therefore, the terminals 23 extending downward in FIG. 1 from the substrate 2 arranged on the side opposite the stator of the main body 31 protrude out of the case 10 on the stator side of the main body 31, which is downward in FIG. 1.

[0032] As shown in Figures 1 and 3, the spacers 33 are cylindrical and extend from the side of the main body 31 opposite the stator toward the opposite stator side from the four corners and the center inside the annular groove 31a, and each have a screw hole 33a that opens from the tip and extends in the axial direction.

[0033] The height of the tip surfaces of the spacers 33 configured in this manner, which are the upper end surfaces in Figure 1, are all the same, and when the substrate main body 21 is placed on the tip surface of each spacer 33, the substrate 2 is placed on the heat sink 3, and the substrate main body 21 and the main body portion 31 face each other in parallel.

[0034] Furthermore, each spacer 33 is provided at a position relative to the main body 31 that coincides with the installation position of the fixing hole 22 in the board main body 21. When the board 2 is placed on the spacer 33, the screw hole 33a faces the fixing hole 22 and the insertion hole 5a of the retaining plate 5. After the board 2 is placed on the spacer 33, the screws 60 inserted into the fixing holes 22 and the insertion hole 5a are screwed into the screw holes 33a of the spacer 33, thereby fixing the board 2 to the heat sink 3. When the board 2 is fixed to the heat sink 3 with the screws 60, the retaining plate 5 attached to the board 2 is also fixed to the spacer 33 of the heat sink 3 together with the board 2, and the retaining plate 5 faces the side of the main body 31 of the heat sink 3 opposite the stator via the connector fixing hole 25 of the board 2.

[0035] The connector fixing hole 25 opens at a position directly opposite the seal ring 6 housed in the seal groove 31b surrounding the terminal insertion hole 32 of the main body 31, and the retaining plate 5 is also positioned directly above the seal ring 6, just like the connector fixing hole 25.

[0036] The connector 4 is made of synthetic resin and has a cylindrical shape with an oval cross section. The connector 4 has a cylindrical tip portion 41 that fits into the terminal insertion hole 32, an oval step portion 42 that projects like a flange from the outer periphery of the tip portion 41 on the substrate 2 side, a cylindrical base portion 43 that also has an oval cross section and rises from the rear end of the step portion 42 on the side opposite the heat sink, and pins 44 that rise from positions on the side opposite the heat sink of the base 43 that face each connector fixing hole 25 and are inserted into the respective connector fixing holes 25. The length of the pins 44 is longer than the length of the substrate main body 21 in the vertical direction in FIG. 1, and the axial length of the base portion 43 is shorter than the length from the side opposite the stator of the main body portion 31 to the tip face of the spacer 33.

[0037] The connector 4 configured as described above is temporarily assembled to the heat sink 3 by inserting and fitting the tip portion 41 into the terminal insertion hole 32 of the main body 31 of the heat sink 3 before attaching the substrate 2 and the retaining plate 5 to the heat sink 3. Specifically, the connector 4 is temporarily assembled to the heat sink 3 by fitting the tip portion 41 into the terminal insertion hole 32 of the main body 31 and bringing the step portion 42 facing the side of the main body 31 opposite the stator into contact with the seal ring 6 housed in the seal groove 31b. The seal ring 6 has an axial height greater than the depth of the seal groove 31b, and its upper portion protrudes from the seal groove 31b toward the side opposite the stator. When the connector 4 is temporarily assembled to the heat sink 3, the step portion 42 is raised from the main body 31 due to the seal ring 6 protruding from the seal groove 31b.

[0038] When the board 2 is placed on the spacer 33 of the heat sink 3 with the connector 4 temporarily assembled to the heat sink 3, the base 43 of the connector 4, which is located on the side of the main body 31 opposite the stator, is accommodated in the space between the main body 31 and the board 2. Furthermore, when the connector 4 is temporarily assembled to the heat sink 3 and the board 2 is placed on the spacer 33, the pins 44 of the connector 4 are inserted into the connector fixing holes 25 in the board 2 and their tips abut against the retaining plate 5. Furthermore, the terminals 23 provided on the board 2 are inserted into the connector 4.

[0039] Furthermore, the step portion 42 of the connector 4 causes the main body portion 31 to be raised by the seal ring 6, and the tip of the pin 44 abuts against the retaining plate 5, so a gap is created between the board main body 21 on the board 2 and the tip surface of the spacer 33, and the board 2 also becomes floating above the spacer 33.

[0040] After temporarily assembling the connector 4 to the heat sink 3 in this manner, the board 2 is placed on the spacer 33 and the pin 44 is inserted into the connector fixing hole 25, whereby the fixing hole 22 in the board 2 and the insertion hole 5a of the retaining plate 5 directly face the screw hole 33a of the spacer 33, and as the screw 60 is inserted through the fixing hole 22 and the insertion hole 5a and screwed into the screw hole 33a, the board 2 and retaining plate 5 move toward the main body 31 and approach the tip surface of the spacer 33. Then, because the retaining plate 5 abuts against the pin 44, the approach of the retaining plate 5 toward the main body 31 moves the connector 4 toward the stator, and the step 42 approaches the main body 31 while compressing the seal ring 6.

[0041] When the screw 60 is screwed deeply into the screw hole 33a, the board main body 21 and the presser plate 5 are sandwiched between the screw 60 and the tip surface of the spacer 33, fixing the board 2 and the presser plate 5 to the heat sink 3. At the same time, the connector 4 receives a load from the presser plate 5 and crushes the seal ring 6, so that the step 42 faces the main body 31 with a small gap between them. The seal ring 6 is crushed as the step 42 approaches the main body 31, and the connector 4 is biased toward the presser plate 5 by a resilient force. The connector 4 is sandwiched between the seal ring 6 and the presser plate 5 and fixed to the heat sink 3. Furthermore, the step 42 of the connector 4 is in close contact with the seal ring 6, sealing the gap between the heat sink 3 and the connector 4. This prevents water from entering from the outside through the gap between the outer periphery of the tip end 41 of the connector 4 and the inner periphery of the terminal insertion hole 32.

[0042] 4, the length L from the lower end surface of the step portion 42 of the connector 4 facing the main body 31 to the upper end surface of the pin 44, which serves as the abutment surface against the pressure plate 5, is shorter than the length X from the upper surface of the main body 31 facing the board 2 to the lower surface facing the connector fixing hole 25 of the pressure plate 5 fixed to the spacer 33. The total length obtained by adding the length W, which the seal ring 6 shown by the dashed line in FIG. 4 protrudes from the seal groove 31b before being compressed by the connector 4, to the length L is longer than the length X. When the pressure plate 5 is fixed to the spacer 33 in this manner, the connector 4 is sandwiched between the seal ring 6 and the pressure plate 5, and the board 2 abuts against the tip surface of the spacer 33 without floating up and is fixed to the heat sink 3 without any play. At the same time, the seal ring 6 is always compressed by the connector 4, and a resilient force is applied to urge the connector 4 toward the pressure plate 5.

[0043] As described above, a crushed margin is provided in the seal ring 6, and the elastic force of the seal ring 6 biases the connector 4 against the pressure plate 5. Therefore, even if a dimensional error occurs in the length L from the step portion 42 to the pin 44 in the connector 4 or the length X from the main body 31 to the pressure plate 5, the error is absorbed by the seal ring 6, and the connector 4 can be reliably fixed to the heat sink 3. However, the length L and the length X may be made equal, and the portion of the connector 4 from the base 43 to the pin 44 may be sandwiched between the pressure plate 5 and the main body 31 to fix the connector 4 to the heat sink 3. In this case, the seal ring 6 may be placed between the inner periphery of the terminal insertion hole 32 in the heat sink 3 and the outer periphery of the tip portion 41 of the connector 4 to seal the gap between the heat sink 3 and the connector 4. Furthermore, in this embodiment, since the pressure plate 5 is attached to the substrate main body 21, when the substrate 2 is placed on the spacer 33, the pressure plate 5 is also placed on the spacer 33 together with the substrate 2, and since the insertion hole 5a faces the screw hole 33a together with the fixing hole 22, the work of fixing the pressure plate 5 to the spacer 33 becomes easier and workability is improved.

[0044] As described above, the electronic device 1 of this embodiment comprises: a substrate 2 having a substrate main body 21 with fixing holes 22, a terminal 23 one end of which is fixed to the substrate main body 21; a metal heat sink 3 comprising: a main body portion 31 facing the substrate 2; a terminal insertion hole 32 provided in the main body portion 31 to allow the terminal 23 to pass through; a spacer 33 rising from the main body portion 31 and having a screw hole 33a facing the fixing hole 22 in the substrate 2; a cylindrical connector 4 made of synthetic resin that is inserted into the terminal insertion hole 32 of the heat sink 3 to accommodate the terminal 23 therein and has a step portion 42 on its outer periphery that faces the main body portion 31 of the heat sink 3; and a retaining plate 5 that is fixed to the spacer 33 together with the substrate 2 by a screw 60 that is screwed into the spacer 33, and that abuts against the connector 4 to fix the connector 4 to the heat sink 3.

[0045] According to the electronic device 1 configured as described above, when fixing the connector 4 to the heat sink 3, the connector 4 is provisionally assembled to the heat sink 3 by fitting the tip 41 of the connector 4 into the terminal insertion hole 32 of the heat sink 3, and then the board 2 and the retaining plate 5 are placed on the spacer 33 without turning the heat sink 3 over, and the screws 60 are screwed into the spacer 33, thereby fixing the connector 4 to the heat sink 3 together with the board 2 and the retaining plate 5. Thus, in the past, after a process of fixing the board to the heat sink with screws, the heat sink was turned over, and then a process of fixing the connector to the heat sink with screws was performed. However, according to the electronic device 1 of the present embodiment, by simply fixing the board 2 to the heat sink 3 with the screws 60 without turning the heat sink 3 over, the connector 4 provisionally assembled to the heat sink 3 can be fixed to the heat sink 3 together with the board 2. Thus, according to the electronic device 1 of the present embodiment, the manufacturing process of the electronic device 1 and the number of screw tightening operations can be reduced, thereby facilitating manufacturing and reducing manufacturing costs.

[0046] Furthermore, the electronic device 1 of this embodiment is provided with a seal ring 6 that is elastic and interposed between the main body 31 and the step 42 of the connector 4, and is compressed by receiving a load from the pressure plate 5 through the connector 4, and the axial length L from the step 42 of the connector 4 to the abutment surface that abuts against the pressure plate 5 is shorter than the length X from the surface of the main body 31 facing the step 42 to the abutment surface of the pressure plate 5 that abuts against the connector 4.

[0047] In the electronic device 1 configured in this manner, when the presser plate 5 is fixed to the spacer 33, the connector 4 is sandwiched between the seal ring 6 and the presser plate 5, and the board 2 abuts against the tip surface of the spacer 33 without floating up, being fixed to the heat sink 3 without any play, and the seal ring 6 is always compressed by the connector 4, causing a resilient force to act on the connector 4 toward the presser plate 5. Furthermore, in the electronic device 1 configured in this manner, the resilient force generated when the seal ring 6 is compressed urges the connector 4 against the presser plate 5, so even if dimensional errors occur in the length L from the step portion 42 to the pin 44 in the connector 4 or the length X from the main body 31 to the presser plate 5, the error is absorbed by the seal ring 6, and the connector 4 can be reliably fixed to the heat sink 3.

[0048] In addition, when the presser plate 5 is provided independently of the board 2 without being attached to the board main body 21, the presser plate 5 may be elastic and bias the connector 4 toward the main body 31 of the heat sink 3. In this case, the axial length L from the step 42 of the connector 4 to the abutment surface that abuts against the presser plate 5 may be longer than the length X from the surface of the main body 31 facing the step 42 to the abutment surface of the presser plate 5 that abuts against the connector 4. When the board 2 and the presser plate 5 are fixed to the spacer 33, the pin 44 protrudes toward the opposite side of the heat sink from the board main body 21 through the connector fixing hole 25, and the presser plate 5 abutting against the tip of the pin 44 bends and applies a biasing force to the connector 4 toward the main body 31. In this case, since the presser plate 5 biases the connector 4, the seal ring 6 does not need to bias the connector 4. The seal ring 6 may be disposed between the outer periphery of the tip 41 of the connector 4 and the inner periphery of the terminal insertion hole 32.

[0049] Furthermore, in the electronic device 1 of this embodiment, the substrate 2 has a connector fixing hole 25, and the retaining plate 5 is disposed on the side of the substrate 2 opposite the heat sink and abuts against the connector 4 through the connector fixing hole 25. With the electronic device 1 configured in this manner, it is easy to place the retaining plate 5 in an appropriate position while visually checking the position of the connector 4, improving workability.

[0050] Furthermore, in this embodiment, pins 44 protruding from base 43 of connector 4 are inserted into connector fixing holes 25 in substrate 2, and pressing plate 5 is brought into contact with pins 44. According to electronic device 1 configured in this manner, inserting pins 44 of connector 4 into connector fixing holes 25 in substrate 2 makes it easy to align pressing plate 5 and connector 4, further improving workability.

[0051] In this embodiment, the pin 44 protruding from the base 43 of the connector 4 is inserted into the connector fixing hole 25 in the board 2, and the presser plate 5 is abutted against the pin 44. However, the pin 44 of the connector 4 may be eliminated, and a pin may be provided on the presser plate 5 that is inserted into the connector fixing hole 25, protrudes further toward the heat sink than the board main body 21, and abuts against the end surface of the base 43 of the connector 4 on the side opposite the heat sink. In this case, when a structure is adopted in which the elastic force of the seal ring 6 presses the connector 4 against the presser plate 5, the pin 44 is eliminated. Therefore, the total length obtained by adding the length from the lower end surface of the step portion 42 of the connector 4 facing the main body 31 to the upper end surface of the base 43 that serves as the abutment surface against the presser plate 5, and the length by which the seal ring 6 protrudes from the seal groove 31b, may be shorter than the length from the upper surface of the main body 31 facing the board 2 to the end surface on the heat sink side of the pin inserted in the connector fixing hole 25 of the presser plate 5 that is fixed to the spacer 33. In addition, when the connector 4 is clamped between the main body 31 and the pin of the pressure plate 5, the length from the lower end surface of the step portion 42 of the connector 4 facing the main body 31 to the upper end surface of the base 43, which serves as the abutment surface that abuts against the pressure plate 5, may be equal to the length from the upper surface of the main body 31 facing the substrate 2 to the heat sink side end surface of the pin inserted into the connector fixing hole 25 of the pressure plate 5 fixed to the spacer 33.

[0052] Furthermore, as in electronic device 1A according to a modification of the embodiment shown in FIG. 5 , pressure plate 5 may be disposed on the heat sink side of substrate 2. According to electronic device 1 configured in this manner, pressure plate 5 is disposed on the heat sink 3 side of substrate 2 and is sandwiched between connector 4 and seal ring 6. This eliminates the need to provide connector fixing holes 25 in board body 21 of substrate 2, and error in the vertical length of board body 21 does not affect the position of pressure plate 5, making dimensional control easier. Furthermore, in this embodiment, when connector 4 is not biased by the elastic force of seal ring 6, base 43 of connector 4 is sandwiched between pressure plate 5 and main body 31, which allows pins 44 of connector 4 to be eliminated. However, pressure plate 5 may be abutted against pins 44 without eliminating pins 44.

[0053] Although the retainer plate 5 is flat in each embodiment, the shape and structure of the retainer plate 5 can be arbitrarily modified as long as it can abut against the connector 4 and fix the connector 4 to the heat sink 3.

[0054] Furthermore, in this embodiment, the electronic device 1 is used to control and drive the motor M, but it goes without saying that it may also be used for electrical devices other than the motor M.

[0055] Although the preferred embodiment of the present invention has been described in detail above, modifications, variations and changes can be made without departing from the scope of the appended claims. [Explanation of symbols]

[0056] 1, 1A... electronic device, 2... board, 21... board body, 22... fixing hole, 23... terminal, 3... heat sink, 25... connector fixing hole, 31... main body, 32... terminal insertion hole, 33... spacer, 33a... screw hole, 4... connector, 42... step portion, 44... pin, 5... retaining plate, 6... seal ring, 60... screw, L... axial length from the step portion of the connector to the abutting surface that abuts against the retaining plate, X... length from the main body to the abutting surface of the retaining plate that abuts against the connector

Claims

1. a substrate having a substrate body with a fixing hole and a terminal one end of which is fixed to the substrate body; a metal heat sink including a main body portion facing the substrate, terminal insertion holes provided in the main body portion to allow insertion of the terminals, and a spacer standing from the main body portion and having screw holes facing the fixing holes in the substrate; a cylindrical resin connector that is inserted into the terminal insertion hole of the heat sink to accommodate the terminal therein, and that has a stepped portion on its outer periphery that faces the main body of the heat sink; a retaining plate that is fixed to the spacer together with the board by a screw that is screwed to the spacer, and that abuts against the connector to fix the connector to the heat sink. An electronic device characterized by:

2. a seal ring having elasticity, interposed between the main body and the step of the connector, and compressed by receiving a load from the pressing plate via the connector; The axial length from the step portion of the connector to the contact surface that contacts the pressing plate is shorter than the length from the surface of the main body that faces the step portion to the contact surface of the pressing plate that contacts the connector.

2. The electronic device according to claim 1, wherein the electronic device is a semiconductor device.

3. the substrate has a fixing hole for a connector; The retaining plate is disposed on the opposite side of the substrate from the heat sink and abuts against the connector through the connector fixing hole.

2. The electronic device according to claim 1, wherein the electronic device is a semiconductor device.

4. The retaining plate is disposed on the heat sink side of the substrate.

2. The electronic device according to claim 1, wherein the electronic device is a semiconductor device.

5. the connector has a pin inserted into the connector fixing hole, The retaining plate abuts against the pin.

4. The electronic device according to claim 3.

Images