Electronic unit and method for manufacturing electronic unit

Abstract

To enable a substrate and a housing to secure a large mounting area for the electronic components on the substrate, while also ensuring that the substrate can be reliably restricted from moving in the rotational direction relative to the housing during positioning.SOLUTION: In an electronic unit 1, an electronic substrate unit 2 has a screw insertion hole 5a through which a shaft portion 4a of screw 4 is inserted, and a positioning recess 5d that is recessed radially outward of the screw insertion hole 5a from a portion of an inner circumferential surface of the screw insertion hole 5a, a housing 3 has a boss 3c into which the shaft portion 4a of screw 4 is screwed, and a positioning protrusion 3f that extends from boss 3c and is inserted into positioning recess 5d, and the screw 4 has the shaft portion 4a threaded into boss 3c through the screw insertion hole 5a, and a head portion 4b connected to shaft portion 4a and abutting the surface of electronic substrate unit 2 from the opposite side of boss 3c.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to an electronic unit and a method for manufacturing the electronic unit. [Background technology]

[0002] For example, Patent Document 1 discloses a substrate fixing structure that fastens and fixes a substrate to a housing. In the substrate fixing structure disclosed in Patent Document 1, positioning holes are provided at the four corners of the substrate. In addition, in the substrate fixing structure disclosed in Patent Document 1, bosses provided on the housing are inserted into the positioning holes, and positioning protrusions formed on the bosses are crimped onto the substrate, thereby fastening the substrate to the housing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-190564 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in Patent Document 1, the positioning protrusion is formed in a circular shape when viewed from the insertion direction into the positioning hole. The positioning hole is also formed in a perfect circle when viewed from the insertion direction. Therefore, even when such a positioning protrusion is inserted into the positioning hole, the relationship between a single positioning protrusion and a single positioning hole makes it impossible to restrict the circuit board in the rotational direction relative to the housing. For example, it is possible to restrict the rotational movement of the circuit board by providing a positioning pin at a position different from the boss and inserting it into a positioning hole different from the positioning hole into which the positioning protrusion is inserted. However, in this case, it is necessary to provide many positioning holes on the circuit board, which reduces the mounting area for electronic components.

[0005] The present invention has been made in consideration of the above-mentioned problems, and aims to connect a circuit board and a housing so that a large mounting area for the board and electronic components on the board can be secured, and to reliably restrict rotational movement of the circuit board relative to the housing when positioning. [Means for solving the problem]

[0006] The present invention employs the following configuration as a means for solving the above problems.

[0007] A first aspect of the present invention is an electronic unit comprising a circuit board on which electronic components are mounted, a housing to which the circuit board is fixed, and a screw for fastening the circuit board to the housing, wherein the circuit board has a screw insertion hole through which the shank of the screw is inserted and a positioning recess recessed from a part of the inner surface of the screw insertion hole radially outward of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed and a positioning protrusion protruding from the boss and inserted into the positioning recess, and the screw has the shank that is screwed into the boss through the screw insertion hole and a head to which the shank is connected and that abuts against the surface of the circuit board from the opposite side of the boss.

[0008] A second aspect of the present invention is a method for manufacturing an electronic unit comprising a circuit board on which electronic components are mounted, a housing to which the circuit board is fixed, and a screw for fastening the circuit board to the housing, wherein the circuit board has a screw insertion hole through which the shank of the screw is inserted and a positioning recess recessed from a portion of the inner surface of the screw insertion hole radially outward of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed and a positioning protrusion protruding from the boss and inserted into the positioning recess, the method comprising a board placement process for positioning the circuit board with respect to the housing so that the positioning protrusion is inserted into the positioning recess, and a fixing process for fixing the circuit board to the housing by screwing the shank of the screw into the boss through the screw insertion hole of the circuit board positioned in the board placement process. [Effects of the Invention]

[0009] According to the present invention, a positioning recess is provided on a portion of the inner circumferential surface of a screw insertion hole in a circuit board. Furthermore, a positioning protrusion provided on a boss is inserted into this positioning recess, thereby positioning the circuit board relative to the housing. When the circuit board is positioned in this manner, the positioning protrusion abuts against the inner wall surface of the positioning recess, thereby restricting rotational movement of the circuit board. Furthermore, there is no need to provide a hole in the circuit board for positioning purposes separate from the screw insertion hole through which the screw is inserted. Therefore, a reduction in the mounting area of electronic components on the circuit board due to the formation of a separate hole can be prevented. Therefore, according to the present invention, a large mounting area for electronic components on the circuit board can be secured between the circuit board and the housing, and rotational movement of the circuit board relative to the housing can be reliably restricted during positioning. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a schematic top view showing a schematic configuration of an electronic unit according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. [Figure 3] FIG. 2 is a schematic top view of an electronic board unit included in the electronic unit according to the embodiment of the present invention. [Figure 4] FIG. 2 is a schematic top view of a housing provided in the electronic unit according to the embodiment of the present invention. [Figure 5] 5A and 5B are schematic enlarged views of a first boss provided on an electronic unit according to an embodiment of the present invention, in which (a) is a top view and (b) is a cross-sectional view taken along line BB of (a). [Figure 6] 1 is a flowchart illustrating a method for manufacturing an electronic unit according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an electronic unit and a method for manufacturing an electronic unit according to the present invention will be described below with reference to the drawings.

[0012] Fig. 1 is a schematic top view showing a general configuration of an electronic unit 1 of this embodiment. Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. The electronic unit 1 of this embodiment is used, for example, as an ECU mounted in a vehicle to control a vehicle system.

[0013] However, the electronic unit 1 of this embodiment can also be applied to electronic units other than ECUs. Specifically, the electronic unit 1 of this embodiment can be applied to an electronic unit including a board on which electronic components are mounted and a housing to which the board is fixed.

[0014] The installation orientation of the electronic unit 1 of this embodiment is not particularly limited. However, for convenience of explanation, as shown in Fig. 1, a direction parallel to the plane of Fig. 1 will be referred to as the left-right direction. Furthermore, a direction parallel to the plane of Fig. 1 and perpendicular to the left-right direction will be referred to as the front-back direction. Furthermore, a direction perpendicular to the left-right direction and the front-back direction will be referred to as the up-down direction.

[0015] 1 and 2, the electronic unit 1 of this embodiment includes an electronic board unit 2 (circuit board), a housing 3, and a plurality of screws 4. Fig. 3 is a schematic top view of the electronic board unit 2. As shown in this figure, the electronic board unit 2 of this embodiment includes a single board 5 and a plurality of electronic components 6.

[0016] The substrate 5 is made of a printed wiring board, and electronic components 6 can be mounted on both the front and back surfaces. As shown in FIG. 3, the substrate 5 is provided with screw insertion holes 5a through which screws 4 are inserted. The screw insertion holes 5a are provided so as to penetrate the substrate 5 in the vertical direction. The substrate 5 is provided with a plurality of screw insertion holes 5a. In this embodiment, the substrate 5 is provided with two screw insertion holes 5a. However, the number of screw insertion holes 5a is not limited to two.

[0017] For ease of explanation, one of the two screw insertion holes 5a (the screw insertion hole 5a located on the left side) will be referred to as the first screw insertion hole 5b. The other of the two screw insertion holes 5a (the screw insertion hole 5a located on the right side) will be referred to as the second screw insertion hole 5c. The first screw insertion hole 5b and the second screw insertion hole 5c are formed to have the same diameter.

[0018] In this embodiment, a positioning recess 5d that is connected to the screw insertion hole 5a when viewed from the top and bottom is provided on the board 5. The positioning recess 5d is a recess into which a positioning protrusion 3f formed on the housing 3 is inserted when positioning the electronic board unit 2 relative to the housing 3.

[0019] In this embodiment, as shown in FIG. 3, two positioning recesses 5d are connected to the first screw insertion hole 5b, and one positioning recess 5d is connected to the second screw insertion hole 5c.

[0020] Each positioning recess 5d is formed to penetrate the substrate 5 in the vertical direction and is formed to be recessed from a part of the inner circumferential surface of the screw insertion hole 5a toward the radially outer side of the screw insertion hole 5a. In this embodiment, each screw insertion hole 5a is formed to have a semicircular shape with a smaller diameter than the screw insertion hole 5a when viewed from the vertical direction.

[0021] However, the shape of each screw insertion hole 5a when viewed from the top and bottom is not limited to a semicircular shape. For example, the shape of each screw insertion hole 5a when viewed from the top and bottom may be a rectangular slit shape.

[0022] The two positioning recesses 5d provided for the first screw insertion hole 5b are arranged opposite each other with the central axis of the first screw insertion hole 5b positioned between them, sandwiching the first screw insertion hole 5b therebetween.

[0023] 2, one of the two positioning recesses 5d provided for the first screw insertion hole 5b is connected to the left side of the first screw insertion hole 5b. The other of the two positioning recesses 5d provided for the first screw insertion hole 5b is connected to the right side of the first screw insertion hole 5b. The position of the positioning recesses 5d relative to the first screw insertion hole 5b can be changed. For example, one positioning recess 5d may be connected to the front side of the first screw insertion hole 5b, and the other positioning recess 5d may be connected to the rear side of the first screw insertion hole 5b.

[0024] 2, the positioning recess 5d provided for the second screw insertion hole 5c is connected to the right side of the second screw insertion hole 5c. The position of the positioning recess 5d for the second screw insertion hole 5c can be changed. For example, the positioning recess 5d may be connected to the left side, front side, or rear side of the second screw insertion hole 5c.

[0025] A plurality of electronic components 6 are mounted on the upper surface of the substrate 5. Note that the electronic components 6 shown in Figures 1 to 3 are only a portion of the electronic components 6, and in reality, a larger number of electronic components 6 can be mounted. Furthermore, electronic components 6 can also be mounted on the lower surface of the substrate 5.

[0026] The housing 3 is a case that houses the electronic board unit 2 and is made of, for example, metal or resin. The housing 3 includes, for example, a cover member that covers the electronic board unit 2 from above. Note that the cover member is omitted in FIG. 1.

[0027] Fig. 4 is a schematic top view of the housing 3. Note that the above-mentioned cover member is also omitted in Fig. 4. As shown in Fig. 4, the housing 3 has a base 3a that supports the electronic board unit 2 from below, and a surrounding wall 3b that surrounds the electronic board unit 2 from the sides.

[0028] The base 3a has a plurality of bosses 3c as shown in Fig. 4. Each boss 3c is formed in a cylindrical shape and has a screw hole 3c1 at the center when viewed from above. Screws 4 are threaded into these bosses 3c, and the electronic board unit 2 is fastened to the housing 3 by the screws 4. Fastening with the screws 4 in this manner fixes the electronic board unit 2 to the housing 3.

[0029] In this embodiment, two bosses 3c are provided. One boss 3c is located below the first screw insertion hole 5b of the substrate 5. The other boss 3c is located below the second screw insertion hole 5c of the substrate 5. For ease of explanation, the boss 3c located below the first screw insertion hole 5b will be referred to as the first boss 3d. Furthermore, the boss 3c located below the second screw insertion hole 5c will be referred to as the second boss 3e.

[0030] 5A and 5B are schematic enlarged views of the first boss 3d, where (a) is a top view and (b) is a cross-sectional view taken along line BB of (a). As shown in these figures, the first boss 3d is provided with two positioning protrusions 3f.

[0031] As shown in Fig. 2, the first boss 3d is formed in a cylindrical shape with an end face 3d1 facing the electronic board unit 2. As shown in Fig. 5, the two positioning protrusions 3f provided on the first boss 3d are each provided to protrude from the end face 3d1 of the first boss 3d. Each of the two positioning protrusions 3f provided on the first boss 3d is a circular protrusion when viewed from above. Furthermore, each positioning protrusion 3f is formed to taper toward its tip.

[0032] The two positioning protrusions 3f provided on the first boss 3d are provided to protrude from an end face 3d1 of the first boss 3d toward the electronic board unit 2. These positioning protrusions 3f are arranged facing each other so that the central axes of the screw holes 3c1 are located between them when viewed from above. The distance between the two positioning protrusions 3f provided on the first boss 3d is equal to the distance between the two positioning recesses 5d provided in the first screw insertion holes 5b.

[0033] Furthermore, the distance between the two positioning protrusions 3f provided on the first boss 3d is such that they overlap with the two positioning recesses 5d provided in the first screw insertion hole 5b when viewed from above, so that the two positioning protrusions 3f provided on the first boss 3d can be inserted into the two positioning recesses 5d provided in the first screw insertion hole 5b.

[0034] The second boss 3e is formed in a cylindrical shape with an end face 3e1 facing the electronic board unit 2. The second boss 3e is provided with one positioning protrusion 3f. The positioning protrusion 3f provided on the second boss 3e is provided so as to protrude from the end face 3e1 of the second boss 3e toward the electronic board unit 2. The positioning protrusion 3f provided on the second boss 3e is a protrusion that has a circular shape when viewed from above. Furthermore, this positioning protrusion 3f is formed so as to taper toward the tip.

[0035] The positioning protrusion 3f provided on the second boss 3e is disposed so as to overlap the positioning recess 5d provided in the second screw insertion hole 5c when viewed from above, so that the positioning protrusion 3f provided on the second boss 3e can be inserted into the positioning recess 5d provided in the second screw insertion hole 5c.

[0036] The screws 4 are fastening members that fasten the electronic board unit 2 to the housing 3. A screw 4 is provided for each boss 3c. That is, the electronic unit 1 of this embodiment includes a screw 4 that is screwed into the first boss 3d and a screw 4 that is screwed into the second boss 3e.

[0037] 2, each screw 4 has a shaft 4a that is screwed into the boss 3c and a head 4b connected to the upper end of the shaft 4a. The shaft 4a is screwed into the boss 3c through a screw insertion hole 5a provided in the board 5. The head 4b abuts against the surface of the electronic board unit 2 (board 5) from the side opposite the boss 3c.

[0038] Next, a method for manufacturing the electronic unit 1 of this embodiment will be outlined with reference to FIG.

[0039] Fig. 6 is a flowchart for explaining a method for manufacturing the electronic unit 1 of this embodiment. As shown in Fig. 6, the method for manufacturing the electronic unit 1 of this embodiment includes a substrate forming step S1, an electronic substrate unit forming step S2, a housing forming step S3, a substrate arranging step S4, a fixing step S5, and a sealing step S6.

[0040] The substrate forming step S1 is a step of forming a substrate 5. That is, a substrate 5 on which electronic components 6 can be mounted is formed in the substrate forming step S1. The electronic substrate unit forming step S2 is a step of mounting electronic components 6 on the substrate 5 to form an electronic substrate unit 2. Here, the electronic components 6 are arranged on the substrate 5 and bonded to the substrate 5 by reflow or the like. Note that if the electronic components 6 are mounted only on the top surface of the substrate 5, the electronic substrate unit forming step S2 can also be performed after the substrate arrangement step S4 or the fixing step S5.

[0041] The housing forming process S3 is a process for forming the housing 3. If the housing 3 is made of metal, the housing 3 is formed by, for example, die casting. If the housing 3 is made of resin, the housing 3 is formed by, for example, injection molding. The housing forming process S3 may be performed in parallel with the substrate forming process S1 or the electronic substrate unit forming process S2. The housing forming process S3 may also be performed before the substrate forming process S1 or the electronic substrate unit forming process S2.

[0042] The board placement step S4 is a step of positioning the board 5 (i.e., the electronic board unit 2 in this embodiment) relative to the housing 3. Here, the board 5 is placed relative to the housing 3 so that the positioning protrusions 3f are inserted into the positioning recesses 5d. The board 5 is positioned relative to the housing 3 by inserting the positioning protrusions 3f into the positioning recesses 5d.

[0043] Specifically, the two positioning protrusions 3f provided on the first boss 3d are inserted into the positioning recesses 5d provided in the first screw insertion hole 5b. Also, the positioning protrusions 3f provided on the second boss 3e are inserted into the positioning recesses 5d provided in the second screw insertion hole 5c. This board placement step S4 prevents the board 5 from moving in the front-back, left-right, and rotational directions relative to the housing 3.

[0044] The fixing step S5 is a step of fixing the substrate 5, which has been positioned relative to the housing 3 in the substrate placement step S4, to the housing 3. Here, the substrate 5 is fastened to the housing 3 using a screw 4. Specifically, the shank 4a of the screw 4 is passed through the screw insertion hole 5a of the substrate 5 from above and screwed into the boss 3c, and the screw 4 is screwed in until the head 4b abuts against the surface of the substrate 5. In this way, the substrate 5 is fastened to the housing 3.

[0045] The sealing step S6 is a step of sealing the electronic board unit 2 inside the housing 3, for example, by attaching a cover member. For example, the cover member is fastened to the surrounding wall portion 3b of the housing 3 from above with screws or the like (not shown).

[0046] The electronic unit 1 of the present embodiment as described above includes an electronic board unit 2, a housing 3, and a screw 4. Electronic components 6 are mounted on the electronic board unit 2. The electronic board unit 2 is fixed to the housing 3. The screw 4 fastens the electronic board unit 2 to the housing 3. The electronic board unit 2 also has a screw insertion hole 5a through which a shank 4a of the screw 4 is inserted and a positioning recess 5d recessed from a portion of the inner circumferential surface of the screw insertion hole 5a toward the radially outer side of the screw insertion hole 5a. The housing 3 also has a boss 3c into which the shank 4a of the screw 4 is screwed, and a positioning protrusion 3f protruding from the boss 3c and inserted into the positioning recess 5d. The screw 4 also has a shank 4a that is screwed into the boss 3c through the screw insertion hole 5a, and a head 4b to which the shank 4a is connected and which abuts against the surface of the electronic board unit 2 from the side opposite the boss 3c.

[0047] According to the electronic unit 1 of this embodiment, a positioning recess 5d is provided on a part of the inner circumferential surface of the screw insertion hole 5a. Furthermore, a positioning protrusion 3f provided on the boss 3c is inserted into this positioning recess 5d, thereby positioning the electronic board unit 2 with respect to the housing 3. When the electronic board unit 2 is positioned in this manner, the positioning protrusion 3f abuts against the inner wall surface of the positioning recess 5d, thereby restricting movement of the electronic board unit 2 in the rotational direction.

[0048] Furthermore, there is no need to provide a hole in the electronic board unit 2 for positioning other than the screw insertion hole 5a through which the screw 4 is inserted. This prevents a reduction in the mounting area of the electronic components 6 in the electronic board unit 2 that would be caused by forming a separate hole. Therefore, according to the electronic unit 1 of this embodiment, it is possible to secure a wide mounting area for the electronic components 6 on the board between the electronic board unit 2 and the housing 3, and to reliably restrict movement of the electronic board unit 2 in the rotational direction relative to the housing 3 during positioning.

[0049] In the electronic unit 1 of this embodiment, the electronic board unit 2 has a screw insertion hole 5a with a plurality of positioning recesses 5d formed therein. The housing 3 has a plurality of positioning protrusions 3f, the same number as the positioning recesses 5d. One positioning protrusion 3f is inserted into each of the positioning recesses 5d.

[0050] According to the electronic unit 1 of this embodiment, by arranging one boss 3c below one screw insertion hole 5a, the positioning protrusions 3f can be inserted into multiple positioning recesses 5d. Therefore, by arranging one boss 3c below one screw insertion hole 5a, the board 5 can be firmly positioned relative to the housing 3. Therefore, for example, according to the electronic unit 1 of this embodiment, it is possible not to provide multiple positioning recesses 5d for other screw insertion holes 5a. It is also possible not to provide positioning recesses 5d for other screw insertion holes 5a.

[0051] In the electronic unit 1 of this embodiment, the electronic board unit 2 has a plurality of screw insertion holes 5a. One of the screw insertion holes 5a is provided with a plurality of positioning recesses 5d. The other screw insertion holes 5a are provided with a single positioning recess 5d.

[0052] According to the electronic unit 1 of this embodiment, it is possible to increase the mounting area for the electronic component 6 around a single positioning recess 5d compared to when multiple positioning recesses 5d are provided for all of the screw insertion holes 5a. Therefore, according to the electronic unit 1 of this embodiment, it is possible to increase the mounting area for the electronic component 6.

[0053] In the electronic unit 1 of this embodiment, the boss 3c is formed in a cylindrical shape with its end face (end face 3d1 or end face 3e1) facing the electronic board unit 2. The positioning protrusion 3f is provided to protrude from the end face of the boss 3c.

[0054] According to the electronic unit 1 of this embodiment, the positioning protrusion 3f can be overlapped with the boss 3c when viewed from above. Therefore, the area of the positioning recess 5d can be reduced compared to when the positioning protrusion 3f protrudes outside the boss 3c when viewed from above. Therefore, according to the electronic unit 1 of this embodiment, the mounting area for the electronic component 6 can be increased.

[0055] Furthermore, in the electronic unit 1 of this embodiment, the positioning protrusion 3f is formed so as to taper toward the tip. According to such an electronic unit 1 of this embodiment, the positioning protrusion 3f can be easily inserted into the positioning recess 5d.

[0056] The manufacturing method of the electronic unit 1 of this embodiment is a manufacturing method of an electronic unit 1 including an electronic board unit 2 on which electronic components 6 are mounted, a housing 3 to which the electronic board unit 2 is fixed, and a screw 4 for fastening the electronic board unit 2 to the housing 3. The electronic board unit 2 has a screw insertion hole 5a through which a shank 4a of the screw 4 is inserted and a positioning recess 5d recessed from a part of the inner circumferential surface of the screw insertion hole 5a toward the radially outer side of the screw insertion hole 5a. The housing 3 has a boss 3c into which the shank 4a of the screw 4 is screwed and a positioning protrusion 3f protruding from the boss 3c and inserted into the positioning recess 5d. The manufacturing method of the electronic unit 1 of this embodiment also includes a board placement step S4 and a fixing step S5. The board placement step S4 is a step of positioning the electronic board unit 2 with respect to the housing 3 so that the positioning protrusion 3f is inserted into the positioning recess 5d. The fixing step S5 is a step of fixing the electronic board unit 2 to the housing 3 by threading the shank 4a of the screw 4 into the boss 3c through the screw insertion hole 5a of the electronic board unit 2 positioned in the board placement step S4.

[0057] According to the manufacturing method of the electronic unit 1 of this embodiment, the positioning protrusion 3f provided on the boss 3c is inserted into the positioning recess 5d, thereby positioning the electronic board unit 2 with respect to the housing 3. Furthermore, there is no need to provide a hole in the electronic board unit 2 for positioning other than the screw insertion hole 5a through which the screw 4 is inserted. Therefore, according to the electronic unit 1 of this embodiment, it is possible to secure a wide mounting area for the board and the electronic components 6 on the board between the electronic board unit 2 and the housing 3, and to reliably restrict movement of the electronic board unit 2 in the rotational direction with respect to the housing 3 during positioning.

[0058] While the preferred embodiments of the present invention have been described above with reference to the accompanying drawings, it goes without saying that the present invention is not limited to the above-described embodiments. The shapes and combinations of the components shown in the above-described embodiments are merely examples, and various modifications can be made based on design requirements, etc., without departing from the spirit of the present invention.

[0059] For example, in the above embodiment, a configuration has been described in which two screw insertion holes 5a are provided in the substrate 5. However, the present invention is not limited to this. For example, a configuration in which a single screw insertion hole 5a or three or more screw insertion holes 5a are provided in the substrate 5 may also be adopted.

[0060] In the above embodiment, a configuration has been described in which a maximum of two positioning recesses 5d are provided for one screw insertion hole 5a. However, the present invention is not limited to this. For example, it is also possible to adopt a configuration in which three or more positioning recesses 5d are provided for one screw insertion hole 5a.

[0061] The above embodiment can also be described as follows, for example:

[0062] (Appendix 1) An electronic unit comprising: a circuit board on which electronic components are mounted; a housing to which the circuit board is fixed; and screws for fastening the circuit board to the housing, the circuit board has a screw insertion hole through which a shank of the screw is inserted, and a positioning recess recessed from a part of an inner circumferential surface of the screw insertion hole toward a radially outer side of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed, and a positioning protrusion that protrudes from the boss and is inserted into the positioning recess, The screw has the shank that is screwed into the boss through the screw insertion hole, and a head that is connected to the shank and abuts against the surface of the circuit board from the side opposite the boss. An electronic unit characterized by:

[0063] (Appendix 2) the circuit board has the screw insertion hole provided with the plurality of positioning recesses, the housing has a plurality of positioning protrusions, the number of which is equal to the number of the positioning recesses; The positioning protrusions are inserted into the positioning recesses one by one. 2. The electronic unit according to claim 1.

[0064] (Appendix 3) the circuit board has a plurality of the screw insertion holes, a plurality of the positioning recesses are provided in one of the plurality of screw insertion holes, The other screw insertion holes are each provided with a single positioning recess. 2. The electronic unit according to claim 1.

[0065] (Appendix 4) The boss is formed in a cylindrical shape with an end surface facing the circuit board, The positioning protrusion is provided to protrude from the end surface of the boss. 4. The electronic unit according to claim 1, wherein the electronic unit is a semiconductor device.

[0066] (Appendix 5) 5. The electronic unit according to claim 1, wherein the positioning protrusion is formed so as to taper toward the tip.

[0067] (Appendix 6) 1. A method for manufacturing an electronic unit including a circuit board on which electronic components are mounted, a housing to which the circuit board is fixed, and screws for fastening the circuit board to the housing, the method comprising: the circuit board has a screw insertion hole through which a shank of the screw is inserted, and a positioning recess recessed from a part of an inner circumferential surface of the screw insertion hole toward a radially outer side of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed, and a positioning protrusion that protrudes from the boss and is inserted into the positioning recess, a board positioning step of positioning the circuit board relative to the housing so that the positioning protrusion is inserted into the positioning recess; a fixing process of fixing the circuit board to the housing by threading the shank of the screw into the boss through the screw insertion hole of the circuit board positioned in the board placement process; have A method for manufacturing an electronic unit comprising: [Explanation of symbols]

[0068] 1...electronic unit, 2...electronic board unit (circuit board), 3...casing, 3a...base, 3b...enclosure wall, 3c...boss, 3c1...screw hole, 3d...first boss, 3d1...end face, 3e...second boss, 3e1...end face, 3f...positioning protrusion, 4...screw, 4a...shank, 4b...head, 5...board, 5a...screw insertion hole, 5b...first screw insertion hole, 5c...second screw insertion hole, 5d...positioning recess, 6...electronic component

Claims

1. An electronic unit comprising: a circuit board on which electronic components are mounted; a housing to which the circuit board is fixed; and screws for fastening the circuit board to the housing, the circuit board has a screw insertion hole through which a shank of the screw is inserted, and a positioning recess recessed from a part of an inner circumferential surface of the screw insertion hole toward a radially outer side of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed, and a positioning protrusion that protrudes from the boss and is inserted into the positioning recess, The screw has the shank that is screwed into the boss through the screw insertion hole, and a head that is connected to the shank and abuts against the surface of the circuit board from the side opposite the boss. An electronic unit characterized by:

2. the circuit board has the screw insertion hole provided with the plurality of positioning recesses, the housing has a plurality of positioning protrusions, the number of which is equal to the number of the positioning recesses; The positioning protrusions are inserted into the positioning recesses one by one.

2. The electronic unit according to claim 1.

3. the circuit board has a plurality of the screw insertion holes, a plurality of the positioning recesses are provided in one of the plurality of screw insertion holes, The other screw insertion holes are each provided with a single positioning recess.

2. The electronic unit according to claim 1.

4. The boss is formed in a cylindrical shape with an end surface facing the circuit board, The positioning protrusion is provided to protrude from the end surface of the boss.

4. The electronic unit according to claim 1, wherein the first and second electrodes are electrically connected to the first and second electrodes.

5. 4. The electronic unit according to claim 1, wherein the positioning protrusion is formed so as to taper toward a tip.

6. 1. A method for manufacturing an electronic unit including a circuit board on which electronic components are mounted, a housing to which the circuit board is fixed, and screws for fastening the circuit board to the housing, the method comprising: the circuit board has a screw insertion hole through which a shank of the screw is inserted, and a positioning recess recessed from a part of an inner circumferential surface of the screw insertion hole toward a radially outer side of the screw insertion hole, the housing has a boss into which the shank of the screw is screwed, and a positioning protrusion that protrudes from the boss and is inserted into the positioning recess, a board positioning step of positioning the circuit board relative to the housing so that the positioning protrusion is inserted into the positioning recess; a fixing process of fixing the circuit board to the housing by threading the shank of the screw into the boss through the screw insertion hole of the circuit board positioned in the board placement process; have A method for manufacturing an electronic unit comprising:

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