Nut and substrate structure

Abstract

To provide a nut that is lightweight and can be firmly fixed to a substrate.SOLUTION: A nut 1 includes at least: an inner cylinder part 10 having an inner peripheral surface 11 in which a female thread 11a is formed; a seating face part 20 extending toward a radial outside from one end of the inner cylinder part 10; and an outer cylinder part 30 extending in an extension direction along a center axis CL of the female thread 11a from an outer peripheral part of the seating face part 20 and integrated with the seating face part 20, where the inner cylinder part 10 extends in the extension direction from the seating face part 20.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a nut and base structure. [Background technology]

[0002] A known nut of this type is formed by drawing a metal plate to form a cylindrical portion and a flange-shaped seat portion at the upper end of the cylindrical portion, and a female thread is formed on the inner peripheral surface of the cylindrical portion. For example, see Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-068782 Summary of the Invention [Problem to be solved by the invention]

[0004] In recent years, boards have been stacked to save space, and such boards may be installed in places where they are subject to relatively large vibrations, such as in automobiles. Nuts are required to be lightweight and to be able to be firmly fixed to the board. [Means for solving the problem]

[0005] A nut of one embodiment of the present invention comprises at least an inner tube portion having a female thread on its inner surface, a seat portion extending radially outward from one end of the inner tube portion, and an outer tube portion extending from the outer periphery of the seat portion in an extension direction along the central axis of the female thread and being integral with the seat portion, wherein the inner tube portion extends in the extension direction from the seat portion.

[0006] A substrate structure of one embodiment of the present invention comprises at least a first substrate, a nut fixed to the first substrate by solder, a second substrate fixed to the first substrate via the nut, and a screw member screwed into the nut to fix the second substrate to the nut, wherein the nut comprises an inner tube portion having a female thread on its inner circumferential surface, a seat portion extending radially outward from one end of the inner tube portion, and an outer tube portion extending from an outer circumferential surface of the seat portion in an extension direction along the central axis of the female thread and integral with the seat portion, wherein the inner tube portion extends from the seat portion in the extension direction, and the solder connects at least the inner and outer circumferential surfaces of the outer tube portion to the first substrate. [Brief description of the drawings]

[0007] [Figure 1] 1A to 1C are cross-sectional views of Examples 1 to 3 of the nut according to the first embodiment. [Diagram 2] 1 is a cross-sectional view of a substrate structure according to a first embodiment. [Diagram 3] FIG. 11 is a perspective view of Example 2 of the nut according to the first embodiment. [Figure 4] FIG. 11 is a perspective view of Example 2 of the nut according to the first embodiment. [Diagram 5] 4A to 4C are cross-sectional views of Examples 4 to 6 of the nut according to the first embodiment. [Figure 6] 1A is a cross-sectional view of Examples 7 and 8 of the nut according to the first embodiment, and a plan view of Example 7. FIG. [Figure 7] 1A to 11 are cross-sectional views of Examples 9 to 11 of the nut according to the first embodiment. [Figure 8] 13A and 13B are cross-sectional views of the nut according to the first embodiment. [Figure 9] 11A and 11B are cross-sectional views of Examples 14 and 15 of the nut according to the first embodiment. [Figure 10] 13A to 13C are cross-sectional views of Examples 16 and 17 of the nut according to the first embodiment. [Figure 11] 18A and 18B are cross-sectional views of the nut according to the first embodiment. [Figure 12] FIG. 11 is a perspective view of a nut according to a second embodiment. [Figure 13] 11A to 11C are cross-sectional views of Examples 2-1 and 2-2 of the nut according to the second embodiment. [Figure 14] 14 is a cross-sectional view taken along line XIV-XIV in FIG. 12 of Examples 2-3 and 2-4 of the nut according to the second embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0008] A nut 1 and a base structure 2 according to a first embodiment will now be described with reference to the drawings. The substrate structure 2 of the first embodiment at least includes a first substrate 51, a second substrate 52, one or more nuts 1, and a screw member 54 such as a bolt that is screwed into the nut 1 (FIG. 2). The substrates 51 and 52 are substrates on which known electronic components such as resistors, capacitors, integrated circuits, diodes, etc. are mounted on one or both sides of their thickness direction depending on the application, function, etc.

[0009] In the first embodiment, as shown in FIG. 2, a hole 52a through which a screw member 54 is inserted is formed in the second substrate 52, and a nut 1 is fixed by solder 60 to the first substrate 51 at a position corresponding to the hole 52a. 1, the nut 1 at least comprises a cylindrical inner tube portion 10 having a female thread 11a formed on its inner circumferential surface 11, a plate-shaped seat portion 20 extending radially outward from one end of the inner tube portion 10, and a cylindrical outer tube portion 30 extending from the outer periphery of the seat portion 20 in an extension direction along the central axis CL of the female thread 11a and integral with the seat portion 20. The outer shapes of the cross sections of the inner tube portion 10 and the outer tube portion 30 may be polygonal or of another shape rather than circular, in which case the seat portion 20 also has an appropriate shape.

[0010] In the first embodiment shown in FIG. 1, the tip 10a of the inner tube 10 in the extending direction is an end member 12, and the tip 10a of the inner tube 10 is closed by the end member 12. The dimension L1 from the surface 20a of the seating surface 20 on the side where the tubes 10 and 30 protrude to the tip of the outer tube 30 is equal to the dimension L2 from the surface 20a to the tip of the inner tube 10, or the dimension L2 is slightly shorter. Note that the dimensions L1 and L2 are dimensions in the extending direction. As a result, even if the first board 51 does not have a hole corresponding to the inner tube 10, the tip 30a of the outer tube 30 is reliably fixed to the first board 51 by the solder 60.

[0011] In addition, in Example 1, the tip portion 10a of the inner cylinder portion 10 is also fixed to the first board 51 by the solder 60, which contributes to increasing the fixing force of the nut 1 to the first board 51. In this case, the end member 12 of the tip portion 10a is the part fixed by the solder 60. When the surface of the end member 12 is fixed to the first board 51 by the solder 60 as in Example 1, the area of ​​the solder for fixing the nut 1 becomes large.

[0012] 1, the dimension L2 is longer than the dimension L1. In this case, an accommodation hole 51a for accommodating the tip side of the inner tube portion 10 is formed in the first substrate 51, and when the tip portion 30a of the outer tube portion 30 is fixed to the first substrate 51 by the solder 60, the tip side of the inner tube portion 10 is accommodated in the accommodation hole 51a. As in the second embodiment, the outer peripheral surface of the tip of the inner tube portion 10 is fixed to the inner peripheral surface of the receiving hole 51a by the solder 60, which contributes to increasing the fixing force of the nut 1 to the first board 51. Note that the tip portion 10a of the inner tube portion 10 in the second embodiment is closed by the end member 12, but the tip of the inner tube portion 10 in the second embodiment may be open without being closed by the end member 12 as in the third embodiment described below. In the second embodiment, the tip side of the inner tube portion 10 is narrowed and a step portion 10b is formed. Such a configuration is useful in cases where a large hole 51a cannot be provided in the first board 51, or when the step portion 10b is brought into contact with the first board 51 to position the nut 1 relative to the board 51.

[0013] In the third embodiment of Fig. 1, the tip of the inner cylindrical portion 10 in the first embodiment is open and not closed by the end member 12. In this case, the female thread 11a can be reliably formed on the entire inner peripheral surface of the inner cylindrical portion 10, which is useful for reducing the dimension of the nut 1 in the extension direction. It is also possible to omit the receiving hole 51a provided in the first substrate 51 in the third embodiment of Fig. 1.

[0014] In the first embodiment, only a part 12a of the end member 12 may be connected to the tip side of the inner cylindrical portion 10, and the other part of the end member 12 may be separated from the base end side of the inner cylindrical portion 10 to form a non-connected part 12b. In this case, the end member 12 is disposed at a position shown by a broken line in the first embodiment of FIG. 1 when forming the female thread 11a on the inner peripheral surface 11, and is disposed at a position shown by a solid line in the first embodiment of FIG. 1 after the female thread 11a is formed. As a result, the female thread 11a is formed over the entire inner peripheral surface 11. This is useful, for example, for reducing the size of the nut 1 in the direction along the central axis CL, and is also useful for ensuring the connection between the screw member 54 and the female thread 11a. A similar configuration can be applied to the end member 12 of the second embodiment. Of course, in the first embodiment, there is also a case where the non-connected part 12b is not provided on the inner cylindrical portion 10 as in the second embodiment. In the first embodiment, the surface of the non-connecting portion 12b extends in a direction intersecting the central axis CL, but the surface of the non-connecting portion 12b may extend in a direction along the central axis CL. Also, there may be a case where a small hole is provided in the radial center of the end member 12.

[0015] When soldering is performed using a heating furnace such as a reflow furnace, it is also possible to perform a solder wicking prevention treatment on the tip portion 10a of the inner tube portion 10 of Example 3 or its vicinity in order to prevent and / or reduce the intrusion of the solder 60 into the female thread 11a. As the solder wicking prevention treatment, a coating called Obi-One (registered trademark) Coat made by Tokushu Kinzoku Excel Co., Ltd., a known treatment using gold plating, etc. can be used.

[0016] In the first embodiment, the nut 1 is formed by pressing and tapping a metal plate such as a known steel plate. For example, in the cases of Examples 1, 2, and 3, a metal plate having a thickness of 0.4 to 2.0 mm is used, and preferably, a metal plate having a thickness of 0.6 to 1.5 mm is used in consideration of both strength and weight. In the cases of Examples 1 and 2, the inner cylinder portion 10 and the end member 12 are formed on a flat metal plate using a press mold having multiple processing stages, and the flat portion on the radial outer side of the inner cylinder portion 10 becomes the seat portion 20, and then the outer cylinder portion 30 is formed using the material on the radial outer side of the seat portion 20. In the case of Example 3, the inner cylinder portion 10 is formed using a similar press mold, and then the outer cylinder portion 30 is formed. Therefore, in the first embodiment, the inner cylinder portion 10 is integral with the seat portion 20, and the outer cylinder portion 30 is also integral with the seat portion 20, and the inner cylinder portion 10, the seat portion 20, and the outer cylinder portion 30 are formed from a single metal plate. 2 and 3 show perspective views of the second embodiment. In the first, second and third embodiments, the inner cylinder portion 10 and the outer cylinder portion 30 may be formed simultaneously, or the outer cylinder portion 30 may be formed prior to the inner cylinder portion 10.

[0017] In one example, the press mold has an upper mold and a lower mold, and punches or dies are provided at positions on the upper mold and lower mold corresponding to the multiple processing stages. As the punch, a drawing punch, a bending punch, a blanking punch, or the like required for each stage is used.

[0018] In the first embodiment, for example, a tap for forming a female thread 11a is inserted into the inner cylindrical portion 10 formed by the above press working, and the female thread 11a is formed according to the shape of the tap. In one example, the tap is attached to a female thread forming machine or the like, and the female thread 11a is formed in the inner cylindrical portion 10 placed at a predetermined position of the female thread forming machine. The female thread forming machine may be provided in the press working machine.

[0019] In the first embodiment, cream-like solder is applied to the soldering portion of the nut 1 on the first substrate 51, the nut 1 is placed on the soldering portion, and in this state, the first substrate 51 and the nut 1 are heated in a heating furnace. As a result, as shown in Examples 1 to 3 in FIG. 1, the inner circumferential surface 31 and the outer circumferential surface 32 of the tip portion 30a of the outer tube portion 30 are connected to the first substrate 51 by the solder 60, for example, by soldering. The inner circumferential surface 31 and the outer circumferential surface 32 may be connected to the first substrate 51 by the solder 60 by a method other than soldering. This configuration is useful for reliably fixing the nut 1 to the first substrate 51. Note that the solder 60 tends to extend over the entire circumference of the inner circumferential surface 31 and the outer circumferential surface 32, but may not be present over the entire circumference depending on the conditions. Also, depending on the conditions, the solder 60 may be attached only to one of the inner circumferential surface 31 and the outer circumferential surface 32.

[0020] As shown in FIG. 2, the screw member 54 is screwed into the nut 1 in such a manner that one thickness-wise surface of the second substrate 52 and / or the head of the screw member 54 contacts the seat 21 of the seat portion 20 of the nut 1 fixed by solder 60, and the second substrate 52 is fixed to the nut 1 and the first substrate 51 by the screw member 54.

[0021] As shown in FIG. 5, a protrusion 33 protruding radially outward may be formed on the outer peripheral surface of the tip 30a of the outer tube portion 30. The protrusion 33 of the fourth embodiment is a flange-shaped protrusion formed by the above-mentioned press working. In one example, the protrusion 33 of the fourth embodiment is formed by pinch trimming. For example, a flat surface extending radially outward from the tip of the outer tube portion 30 is formed during press working, and the flat surface is cut by cutting during the press working to form the flange-shaped protrusion 33 of the fourth embodiment. When pinch trimming is used as in the fourth embodiment, the flatness of the tip surface of the outer tube portion 30 is easily improved, which contributes to improving the strength, dimensional accuracy, etc. of the substrate structure 2.

[0022] The protrusion 33' in Example 5 is formed when cutting the metal plate at a position corresponding to the tip surface of the outer tube portion 30 in the aforementioned press processing, or is formed by applying force with a mold to the tip surface of the outer tube portion 30 in the aforementioned press processing. The protrusion 33'' in Example 6 is formed by forming the outer tubular portion 30 to expand toward its tip by the above-mentioned press processing. As shown in FIG. 5, in a cross section passing through the central axis CL of the nut 1, the angle α between a line along the direction in which the entire outer tubular portion 30 or the outer circumferential surface 32 on the tip side of the outer tubular portion 30 in Example 6 extends and the direction in which the central axis CL extends is 2° or more. There may be cases in which the angle α is approximately 40°. Even in this case, it can be said that the outer tubular portion 30 extends from the outer periphery of the seat portion 20 in the direction along the central axis CL.

[0023] The protruding height L3 of the protruding portions 33, 33', 33'' may be 0.02 mm or more, and the protruding portions 33, 33', 33'' may be provided at a plurality of positions in the circumferential direction of the outer tubular portion 30 at intervals from each other. Examples 4 to 6 can be applied to Examples 1 to 3 as necessary. The configurations of Examples 4 to 6 have the effect of making it difficult for the outer tubular portion 30 to come off the solder 60 in the extending direction.

[0024] For example, in Example 4, multiple notches 34 may be formed in the protruding portion 33 as in Example 7 in Fig. 6. The notches 34 may extend to the base end side or the middle part of the outer tube portion 30. As shown in the bottom view of Example 7 in Fig. 6, multiple notches 34 are provided at intervals in the circumferential direction of the outer tube portion 30. This configuration contributes to increasing the contact area between the solder 60 and the outer tube portion 30, forming a circumferential catch between the solder 60 and the outer tube portion 30, etc. There may also be a case where only one notch 34 is provided. 6, a hole 35 may be formed penetrating the outer tubular portion 30. The hole 35 and the notch 34 extending to the base end side or the middle part of the outer tubular portion 30 as described above function to vent gas from the space S. Examples 7 and 8 can be applied to Examples 1 to 6 as necessary.

[0025] As shown in FIG. 7, an inner cylinder protrusion 13 protruding radially outward may be formed on the outer peripheral surface of the tip end 10a of the inner cylinder 10. The inner cylinder protrusion 13 of the embodiment 9 of FIG. 7 is formed by applying a force in a direction along the central axis CL to the tip end 10a with a mold in the press working described above. In the embodiment 9, an inclined surface 13a inclined with respect to the tip end surface is formed on the outer peripheral surface side of the tip end surface of the inner cylinder 10, and thus the inner cylinder protrusion 13 is formed on the tip end 10a of the inner cylinder 10. The protruding height of the inner cylinder protrusion 13 is typically about 1 / 2 or less than 1 / 2 of the plate thickness of the material of the inner cylinder 10 or the seat surface portion 20. The inner cylinder protrusion 13' of the embodiment 11 of FIG. 7 is formed as a protrusion protruding radially from the bottom surface of the groove 14 by forming a groove 14 by machining or the like on a part of the tip side of the outer peripheral surface of the inner cylinder 10. A protrusion similar to the inner cylinder protrusions 13, 13' may be provided on the outer cylinder 30.

[0026] Furthermore, as in Example 11 of Figure 7, an inner tube protrusion 13'' protruding radially outward may be formed on the outer peripheral surface of the tip portion 10a of the inner tube portion 10 by applying a force in a direction along the central axis CL to the tip portion 10a using a mold in the above-mentioned press processing. Furthermore, as in Example 12 of Figure 8, unevenness may be formed in the area where connection is made by solder 60 on the outer peripheral surface of the inner tube portion 10, without providing inner tube protrusions 13, 13', 13'' on the outer peripheral surface of the inner tube portion 10.

[0027] The unevenness is formed, for example, by forming unevenness on the press mold by electric discharge machining or the like, and pressing the unevenness against the outer peripheral surface of the inner tube portion 10 by the press process. For example, by forming the unevenness on the outer peripheral surface of the inner tube portion 10, the measurement value of the arithmetic mean roughness (Ra) when measured by a surface roughness measuring device is substantially larger in the area where the unevenness is formed than in the area where the unevenness is not formed. There may be a case where scratches are actively made on the outer peripheral surface of the inner tube portion 10 during the press process, and the scratches function as the unevenness. The same effect is obtained even if the unevenness of Example 12 is provided on the outer peripheral surface of the short inner tube portion 10 of Examples 1 and 3. In addition, the unevenness of Example 12 may be provided in the area where the connection by the solder 60 is performed on the outer peripheral surface 32 of the outer tube portion 30. In addition, as in Example 13 of FIG. 8, an inner tube protrusion 13 may be formed on the tip end 10a of the long inner tube portion 10.

[0028] Examples 9 to 13 can be applied to Examples 1 to 8 as necessary. The configurations of Examples 9 to 13 have the effect of making it difficult for the inner cylindrical portion 10 to come off the solder 60 in the extending direction. The tip portion 10a of the inner cylindrical portion 10, the tip portion 30a of the outer cylindrical portion 30, etc. may be machined as necessary.

[0029] The nut 1 of the first embodiment is lighter in weight by the radial space S between the inner cylinder portion 10 and the outer cylinder portion 30, and both the inner circumferential surface 31 and the outer circumferential surface 32 of the tip portion 30a of the outer cylinder portion 30 are used for connection to the first board 51 by the solder 60, which contributes to improving the fixing force of the nut 1 to the board. This effect cannot be obtained with a forged nut, and the nut in the prior art document does not have a configuration equivalent to the outer cylinder portion 30, so this effect cannot be obtained. The distance between the inner cylinder portion 10 and the outer cylinder portion 30 is 1.5 mm or more, preferably 2 mm or more, and more preferably 2.5 mm or more. Depending on the conditions, the distance between the cylinder portion 10 and the outer cylinder portion 30 may be 1.5 mm or less.

[0030] In the first embodiment, the position of the outer periphery of the seating surface portion 20 may be shifted in the direction along the central axis line CL relative to the inner periphery as in Example 14 of FIG. 9. The position of the outer periphery of the seating surface portion 20 may be shifted in the opposite direction to Example 14. In FIG. 2, most of the seating surface portion 20 contacts the second substrate 52, but in Example 14, the inner periphery and the central side in the radial direction of the seating surface portion 20 contact the second substrate 52. Depending on the shape of the seating surface portion 20, only the outer periphery or the central side in the radial direction of the seating surface portion 20 may contact the second substrate 52. The seating surface portion 20 may have other shapes. In a cross section passing through the central axis line CL, the acute angle between the overall extension direction of the seating surface portion 20 and the central axis line CL may be about 45°. Even in these cases, the seating surface portion 20 is a portion having a seating surface 21, and the seating surface portion 20 extends at least radially outward from one end of the inner cylinder portion 10. The seating surface portion 20 extends radially outward from one end of the inner cylindrical portion 10, and the outer cylindrical portion 30 extends from the outer periphery of the seating surface portion 20 in a direction along the central axis line CL.

[0031] In each of the above embodiments, the overall shape of the nut 1 consisting of the inner tubular portion 10, the seat portion 20, and the outer tubular portion 30 is produced by pressing a metal plate, so that the load required for processing is less than that of a forged nut, contributing to smaller equipment and less energy required, and also making it possible to reduce the time required to manufacture each nut compared to a forged nut.

[0032] In each of the above embodiments, as in embodiment 15 of FIG. 9, it is also possible to prepare the inner cylindrical portion 10' separately and to fix the inner cylindrical portion 10' to the seat portion 20 by fitting, welding, adhesive or the like. In each of the above embodiments, the height of the nut 1 can be increased because the space S reduces the weight and the inner circumferential surface 31 of the outer cylinder portion 30 is connected to the first board 51 by the solder 60 to improve the fastening strength. Furthermore, the height of the nut 1 can be freely set because the nut 1 is formed using a thin metal plate.

[0033] 10, the dimension L4 between the tip of the outer cylindrical portion 30 and the tip of the inner cylindrical portion 10 in the direction along the central axis CL may be 1 mm or more. In this case, even if the end member 12 is not provided on the inner cylindrical portion 10, solder wicking onto the female thread 11a can be effectively prevented.

[0034] 10, a radial extension portion 10c extending radially outward may be formed on the tip side of the inner cylinder portion 10. The extension portion 10c is formed integrally with the inner cylinder portion 10, and in the seventeenth embodiment, the tip of the inner cylinder portion 10 is the extension portion 10c. The surface 10d of the extension portion 10c on the first substrate 51 side is preferably inclined with respect to the first substrate 51 as in the seventeenth embodiment. For this reason, during soldering using a heating furnace such as a reflow furnace, the solder tends to accumulate in the space between the surface 10d and the first substrate 51, and even if the end member 12 is not provided on the inner cylinder portion 10, the solder wicking to the female thread 11a can be effectively prevented.

[0035] Also, as in Example 17 of Fig. 10, a chamfered solder wicking prevention surface 10e may be provided on the surface 10d. The solder wicking prevention surface 10e faces the tip of the inner cylinder portion 10 in the direction along the central axis CL, that is, faces the lower side of Fig. 10. The angle between the solder wicking prevention surface 10e and the first substrate 51 is preferably 30° or more. This configuration makes it easier for solder to accumulate in the space between the solder wicking prevention surface 10e and the first substrate 51, and solder wicking to the female thread 11a can be more effectively prevented.

[0036] 11, a radial extension 10f extending radially outward may be formed on the tip side of the inner cylindrical portion 10. The extension 10f is formed integrally with the inner cylindrical portion 10, and in Example 17, the tip of the inner cylindrical portion 10 is the extension 10f. A solder wicking prevention surface 10g facing the tip side of the inner cylindrical portion 10 in the direction along the central axis CL is formed on the inner circumferential surface 11 on the tip side of the female thread 11a of the inner cylindrical portion 10.

[0037] In the eighteenth embodiment, a hole 10h having a diameter larger than the small diameter portion of the female screw 11a is formed on the tip side of the inner cylindrical portion 10, and a solder wicking prevention surface 10g is formed by the formation of the hole 10h. Therefore, during soldering using a heating furnace such as a reflow furnace, the solder tends to accumulate on the first board 51 side rather than on the solder wicking prevention surface 10g, and even if the inner cylindrical portion 10 is not provided with an end member 12, solder wicking to the female screw 11a can be effectively prevented. Surface 10d and solder wicking prevention surfaces 10e and 10g are formed by applying force with a mold to the corresponding locations of inner cylindrical portion 10, but they may also be formed by other methods such as machining. Note that bending the tip side of inner cylindrical portion 10 radially outward as in Examples 17 and 18 is useful for forming solder wicking prevention surfaces.

[0038] 11, a groove 10i may be formed by machining or the like on the inner peripheral surface 11 of the inner cylindrical portion 10 on the tip side of the female thread 11a, and a solder wicking prevention surface 10j may be formed by forming the groove 10i. The solder wicking prevention surfaces 10e, 10g, and 10j are disposed closer to the female thread 11a than the tip of the inner cylindrical portion 10 in the direction along the central axis CL. Depending on the conditions, the solder wicking prevention surfaces 10e, 10g, and 10j may be curved.

[0039] The extensions 10c and 10f in Examples 17 and 18 can function as inner cylinder protrusions similarly to Example 9, etc. At least one of the surface 10d and the solder wicking prevention surfaces 10e, 10g, and 10j can be applied, as necessary, to Example 3 or Example 2 in which the end member 12 is not provided, and can also be applied, with necessary modifications, to Examples 4 to 15.

[0040] The nut 1 and the base plate structure according to the second embodiment will be described below with reference to the drawings. The board structure of the second embodiment is the same as that of the first embodiment, except that the nut 1 is changed to a nut 3. That is, the nut 3 is fixed to the first board 51 by solder 60, a screw member 54 is screwed into the nut 3, and the second board 52 is fixed to the nut 3 and the first board 51 by the screw member 54. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof will be omitted.

[0041] The nut 3 is formed by stacking and joining a plurality of plate-shaped members 4 together. Each plate-shaped member 4 is formed by performing a stamping process on a metal plate. In this embodiment, as shown in Fig. 12, the outer periphery 4a of each plate-shaped member 4 is polygonal and the inner hole 4b of each plate-shaped member 4 is circular, but the outer periphery of each plate-shaped member 4 may be circular or have another shape.

[0042] As shown in Examples 2-1 and 2-2 in Fig. 13, the inner holes 4b of the multiple plate-like members 4 joined together become the inner peripheral surface of the nut 3, and a female screw 6a is formed on the inner peripheral surface by tapping in the same manner as in the first embodiment. In Example 2-1, the inner hole 4b is not provided in the end plate-like member 4, and therefore one end of the female screw 6a is closed. Even in this case, the end plate-like member 4 can be attached after the female screw 6a is formed, so that the female screw 6a is reliably formed over the entire inner peripheral surface. In Example 2-2, both ends of the female screw 6a are open.

[0043] An engagement portion 5 is formed in each plate-like member 4. In one example, as in Example 2-3 and Example 2-4 of FIG. 14, the engagement portion 5 is formed by using a known half-punch process, which is sometimes called cutting and bending, during press working. In Example 2-3, the engagement piece 5a is half-punched in each plate-like member 4 by press working. At this time, the entire circumference of the engagement piece 5a is not cut from the plate-like member 4, and a part of the engagement piece 5a is not cut from the plate-like member 4. By bending at least a part of the engagement piece 5a in the plate-like member 4 in the plate thickness direction, the engagement piece 5a protrudes from one surface in the plate-like member 4 in the thickness direction to form an engagement protrusion 5b, and an engagement recess 5c is formed on one surface in the plate thickness direction of the plate-like member 4 by the amount of protrusion of the engagement protrusion 5b.

[0044] In Example 2-4, the engaging piece 5d is half-punched by press working in each plate-like member 4. As a result, the engaging piece 5d protrudes from one surface in the thickness direction of the plate-like member 4 to form an engaging protrusion 5e, and an engaging recess 5f is formed on one surface in the plate thickness direction of the plate-like member 4 by the amount of protrusion of the engaging protrusion 5e.

[0045] A plurality of plate-like members 4 are stacked, and the engaging protrusions 5b, 5e of one of two adjacent plate-like members 4 are inserted into the engaging recesses 5c, 5f of the other plate-like members 4, thereby joining the plate-like members 4 to each other. In this configuration, the engaging protrusions 5b, 5e and the engaging recesses 5c, 5f are formed during press working, and the joining of the plate-like members 4 is ensured. This is useful for both ensuring the functionality of the nut 3 and reducing manufacturing costs. The engaging protrusions 5b, 5e of the plate-like members 4 at the ends of the nut 3 in the stacking direction may be removed by machining or the like, and it is also possible to use plate-like members 4 without the engaging protrusions 5b, 5e as the plate-like members 4 at the ends of the nut 3 in the stacking direction.

[0046] In another example, the multiple plate-like members 4 are bonded to each other using an adhesive, welding, etc. In yet another example, a cylindrical member is fitted onto the outer peripheral surfaces of the multiple plate-like members 4 stacked on top of each other, and the multiple plate-like members 4 are bonded to each other by an annular member.

[0047] In the first embodiment, the outer cylinder 30 may have one or more legs protruding from its tip, and the first board 51 may have a leg receiving hole into which the leg is inserted. The one or more legs are formed by pressing. For example, when the mounting position on the board is specified, the position of the nut 1 relative to the board is fixed by one or more legs that are partial extensions of the outer cylinder. This configuration also prevents the position of the nut 1 from shifting around the central axis CL. It is also possible to provide similar legs to the nut 3 of the second embodiment.

[0048] In the first embodiment, the press mold having a plurality of processing stages may be configured so that the punch and die of each stage can be replaced with a punch and die for forming a nut 1 of another size. The nut 1 of another size is, for example, a nut having a different diameter of the female thread 11a.

[0049] Furthermore, by preparing nuts 1 of multiple sizes, the user has more design options when stacking and fixing the second board 52 to the first board 51. In this case, even when using a relatively large nut 1 with a nominal diameter of the female thread 11a of M5 (5 mm) or more, M6 (6 mm) or more, or a nut 1 with a large height dimension, the nut 1 is made lighter by the space S, so the user can easily solve problems such as vibration input to the board, and can also achieve reliable fixing by the solder 60 described above. In the second embodiment, by preparing nuts 3 of a plurality of sizes, the user's design options for overlapping and fixing second substrate 52 to first substrate 51 are similarly expanded. [Explanation of symbols]

[0050] 1,3 Nut 2. Board structure 10 Inner cylinder 10e, 10g, 10j Solder wicking prevention surface 11a Female thread 12 End member 20 Seat part 30 Outer cylinder 33 Protrusion 51 First board 52 Second board 54 Screw material 60 Solder CL center axis

Claims

1. An inner cylindrical portion having a female screw formed on an inner circumferential surface thereof; a seat portion extending radially outward from one end of the inner cylindrical portion; An outer cylinder portion extending from an outer periphery of the seat portion in an extension direction along the central axis of the female screw and integral with the seat portion, The inner cylinder portion extends from the seat portion in the extension direction.

2. The nut according to claim 1 , wherein a tip end portion of the inner cylindrical portion in the extending direction is closed by an end member.

3. The nut according to claim 1 , wherein a protrusion protruding radially outward is formed on an outer circumferential surface of a tip end portion of the outer tubular portion in the extending direction.

4. The nut according to claim 1 or 2, wherein an inner cylinder protruding portion protruding radially outward is formed on an outer circumferential surface of a tip end portion of the inner cylinder portion in the extending direction.

5. 3. The nut according to claim 1, wherein a solder wicking prevention surface is formed on the inner circumferential surface of the inner cylindrical portion on the tip side of the female thread, the solder wicking prevention surface facing the tip side of the inner cylindrical portion in the direction along the central axis.

6. A first substrate; a nut fixed to the first substrate by soldering; a second substrate fixed to the first substrate via the nut; a screw member that is screwed into the nut to fix the second substrate to the nut, The nut is An inner cylindrical portion having a female screw formed on an inner circumferential surface thereof; a seat portion extending radially outward from one end of the inner cylindrical portion; An outer cylinder portion extending from an outer periphery of the seat portion in an extension direction along the central axis of the female screw and integral with the seat portion, The inner cylinder portion extends in the extension direction from the seat portion, A substrate structure, wherein the solder connects at least the inner and outer circumferential surfaces of the outer cylinder portion to the first substrate.

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