JP2018179207A - Nut and connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a nut with which a connection state of the nut and a substrate is easily checked.SOLUTION: A nut includes: a base part 11 having a first face 11a and a second face 11b provided on the opposite side to the first face 11a; a shaft part 12 arranged on the second face 11b of the base part 11, and extending from the second face 11b toward the opposite side to the first face 11a; and a hole part 13 penetrating the base part 11 from the first face 11a side toward the second face side, and extending at least to the inside of the shaft part. The base part 11 has a base part body 11c where the hole part 13 is arranged, and a thin thickness part 14 whose thickness is gradually made thinner from the base part body 11c side toward a peripheral part of the base part 11 so that the second face 11b approaches the first face 11a.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a nut and a joint structure.

  2. Description of the Related Art Conventionally, components are soldered and joined to a substrate such as a printed circuit board.

  The parts are mechanically and electrically joined to the substrate by soldering. At the joint between the component and the substrate, a joint failure may occur depending on the process capability.

  Therefore, in order to confirm the bonding state of the component to the substrate, inspection of the bonding state in which the component is soldered is performed.

  For example, Patent Document 1 proposes that a lead terminal of a component inspects a joint state of soldering based on the solder amount of a joint portion soldered to a through hole and a land of a substrate.

  Specifically, Patent Document 1 performs a surface treatment to prevent the molten solder from wetting the portion of the lead terminal protruding from the back side of the non-appearing substrate when performing visual inspection of the bonding state of the lead terminal. It is proposed to adjust the amount of solder on the front side of the substrate which can be seen, and to carry out the appearance inspection of the joint.

JP, 2002-124761, A

  As described above, it is considered that various methods can be proposed for each part to facilitate visual inspection of the bonding state of the soldering by devising the parts.

  For example, in order to fix a bolt to a substrate, a nut coupled to the bolt may be soldered to the substrate in advance.

  In order to mechanically or electrically bond the bolt to the substrate, first, the nut is mechanically or electrically bonded to the substrate. The bonding state between the nut and the substrate by soldering is confirmed by, for example, an appearance inspection.

  In the present specification, it is an object of the present invention to provide a joint structure including a nut and a nut that facilitates inspection of a joint state of a nut and a substrate.

  According to the nut disclosed herein, a base having a first surface and a second surface provided on the opposite side of the first surface, and a second surface disposed on the second surface of the base from the second surface And a shaft portion extending toward the side opposite to the first surface, and a hole portion penetrating the base portion from the first surface side to the second surface side and extending at least to the inner side of the shaft portion. It has a base body in which a hole is arranged, and a thin part whose thickness is reduced so that the second surface approaches the first surface from the base body side toward the periphery of the base.

  Further, according to the joint structure disclosed in the present specification, a base having a first surface and a second surface provided on the opposite side of the first surface, and a second surface disposed on the second surface of the base And a shaft portion extending from the surface toward the opposite side to the first surface, and a hole extending through the base from the first surface side to the second surface side and extending at least to the inside of the shaft portion, The base has a base body in which the hole is disposed, and a nut having a thin portion whose thickness decreases so that the second surface approaches the first surface from the base body side toward the periphery of the base, A substrate having a substrate main body having three surfaces and a fourth surface, a substrate having a through hole penetrating the substrate main body from the third surface to the fourth surface and into which the shaft portion can be inserted, and a second surface of the base And a part of the shaft part and the solder for joining the substrate, and the nut is a through hole in the shaft part with the base exposed on the third surface of the substrate It is inserted.

  According to the nut disclosed in the specification described above, it becomes easy to inspect the bonding state between the nut and the substrate.

  Moreover, according to the joint structure provided with the nut disclosed in the present specification described above, it becomes easy to inspect the joint state of the nut and the substrate.

It is sectional drawing which shows the joining structure of a prior art example. (A) is a top view which shows 1st Embodiment of the junction structure disclosed to this specification, (B) is XX sectional drawing of FIG. 2 (A). (A) is a plan view of the nut, (B) is a front view of the nut, and (C) is a perspective view of the nut. It is a top view of a substrate. It is a figure in which the volt | bolt was joined to the joining structure of 1st Embodiment. (A) is a cross-sectional view showing a second embodiment of the joint structure disclosed in the present specification, (B) is a plan view of a nut, and (C) is a front view of the nut. (A) is a cross-sectional view showing a third embodiment of the joint structure disclosed in the present specification, and (B) is a front view of a nut. (A) is a cross-sectional view showing a fourth embodiment of the joint structure disclosed in the present specification, and (B) is a front view of a nut. It is sectional drawing which shows 5th Embodiment of the joining structure disclosed to this specification.

  First, the joint structure provided with the conventional nut and the subject in the visual inspection of this joint structure are demonstrated below.

  FIG. 1 is a cross-sectional view showing a conventional joint structure.

  The joint structure 101 includes a substrate 120 having a through hole 122, and a nut 110 which is soldered in a state of being inserted into the through hole 122 and joined to the substrate 120.

  The substrate 120 is electrically insulating and includes a substrate body 121 having a first surface 121 a and a second surface 121 b.

  The through hole 122 penetrates the substrate main body 121 from the first surface 121 a side to the second surface 121 b side.

  A layered conductive portion 123 having electrical conductivity is disposed on the periphery of the opening on the first surface 121 a side of the through hole 122 and the periphery of the opening on the second surface 121 b side, and on the surface of the through hole 122. Ru. The conductive portion 123 includes a first land 123a disposed on the periphery of the opening on the first surface 121a side, a second land 123c disposed on the periphery of the opening on the second surface 121b, and a surface of the through hole 122 It has a through-hole conductive portion 123b disposed on the top.

  The nut 110 has a disk-shaped base 111 and a cylindrical shaft 112.

  The base 111 has a second surface 111b provided on the opposite side of the first surface 111a and the first surface 111a. The second surface 111 b faces the first surface 121 a of the substrate 120. The first surface 111 a is exposed outward.

  The shaft portion 112 is disposed on the second surface 111 b of the base 111, and extends from the second surface 111 b to the opposite side to the first surface 111 a.

  The nut 110 has a hole portion 113 which penetrates the base portion 111 from the first surface 111 a side to the second surface 111 b side and extends through the inside of the shaft portion 112.

  The shaft portion 112 has a cylindrical shape as a whole, and is disposed on the second surface 111 b of the base portion 111 with the central axis aligned with the center of the disc-shaped base portion 111.

  The shaft portion 112 is inserted into the through hole 122 in a state where the base 110 is exposed on the first surface 121 a of the substrate 120.

  The nut 110 is fixed to the substrate 120 by bonding the second surface 111 b of the base 111 and a part of the shaft portion 112 to the conductive portion 123 using the solder 130.

  Soldering of the nut 110 and the substrate 120 is performed using, for example, a reflow method.

  The bonding state between the nut 110 and the substrate 120 by soldering is performed by visual inspection from the first surface 121 side of the substrate 120. Specifically, in the appearance inspection, as shown in the frame A1 in FIG. 1, the presence or shape of the inclined portion 130 a of the solder 130 obliquely extending from the end of the base 111 to the end of the first land 123 a It is done on the basis of The inclined portion 130a reflects the inspection light irradiated by the visual inspection, whereby the presence or the shape of the inclined portion 130a is measured, and the bonding state of the soldering is inspected.

  For example, as shown in the frame A1 in FIG. 1, when the inclined portion is not formed, the nut 110 and the conductive portion 123 of the substrate 120 are mechanically and electrically joined, for example. Also, the bonding state by soldering was sometimes judged to be defective.

  Therefore, the solder of the nut 110 and the substrate 120 is soldered using a sufficient amount of solder so that the inclined portion 130a is formed between the end of the base 111 and the end of the first land 123a. . Then, as shown by a frame A3 in FIG. 1, the solder overflowing from between the outer surface of the shaft portion 112 and the in-hole conductive portion 123b may wrap around into the hole portion 113 in the shaft portion 112.

  In this case, when a bolt (not shown) coupled to the nut 110 is screwed into the hole 113, the solder 130 in the hole 113 is scraped off, resulting in a problem of generation of solder debris.

  Hereinafter, a first preferred embodiment of a joint structure provided with a nut disclosed herein which can solve the above-mentioned problems will be described with reference to the drawings. However, the technical scope of the present invention is not limited to those embodiments, but extends to the invention described in the claims and the equivalents thereof.

  FIG. 2A is a plan view showing a first embodiment of the junction structure disclosed in the present specification, and FIG. 2B is a cross-sectional view taken along the line X-X of FIG. FIG. 3 (A) is a plan view of the nut, FIG. 3 (B) is a front view of the nut, and FIG. 3 (C) is a perspective view of the nut. FIG. 4 is a plan view of the substrate. FIG. 5 is a view in which a bolt is joined to the joint structure of the first embodiment.

  The bonding structure 1 of the present embodiment includes a substrate 20 on which a nut 10 and a nut 10 are bonded by a solder 30.

  The nut 10 is used, for example, to secure the bolt 40 to the substrate 20 as shown in FIG. The bolt 40 electrically connects the washer 43 connected with the lead 44 to the substrate 20. Thus, the conducting wire 44 electrically connected to the washer 43 is electrically connected to the substrate 20.

  Thus, the nut 10 can be used to mechanically or electrically bond other components to the substrate 20 using bolts or the like.

  The substrate 20 is electrically insulating and has a substrate body 21 having a first surface 21a and a second surface 21b, a through hole 22, a first land 23a, a conductive portion 23b in a through hole, and a second land 23c. A conductive portion 23 is provided. The description of the substrate 120 in FIG. 1 described above also applies to the description of each part of the substrate 20.

  As shown in FIG. 4, the first lands 23 a are disposed on the periphery of the opening on the first surface 21 a side of the through hole 22. The first land 23a has a circular outline and has an opening at the center where the through hole 22 is exposed. The first land 23a has a pair of extending portions 23d at opposing positions on the outer periphery thereof. The extending portion 23 d extends outward from the inner side of the first land 23 a.

  The second land 23c is disposed at the periphery of the opening on the second surface 21b side of the through hole 22 in the same manner as the first land 23a except that the second land 23c does not have a pair of extending portions.

  The through hole 22 has a cylindrical space and has a dimension capable of receiving the shaft 12.

  The conductive portion 23 can be electrically connected to a wiring (not shown) on the substrate 20 and grounded.

  The nut 10 has a disk-shaped base 11, a cylindrical shaft 12 whose central axis coincides with the base 11 and extends from the second surface 11 b to the opposite side to the first surface 11 a, and the base 11. And a hole 13 extending to at least the inside of the shank 12. In the joint structure 1, the hole 13 penetrates the base 11 and the shaft 12. The description of the nut 110 in FIG. 1 described above also applies to the description of each part of the nut 10. The shaft 12 has a cylindrical shape by providing a cylindrical hole 13 inside.

  As shown in FIG. 3B, the corner on the free end side of the shaft 12 is chamfered so that the shaft 12 can be easily guided into the through hole 22.

  The hole 13 is a space into which the shaft 42 of the bolt 40 is inserted, as shown in FIG. In the case where the shaft 42 of the bolt 40 is provided with an external thread, it is preferable that the surface of the hole 13 be provided with an internal thread to be engaged with the external thread.

  As shown in FIG. 2B, the base 11 of the nut 10 has a portion extending outward from the shaft 12 when the shaft 12 of the nut 10 is inserted into the through hole 22. The first surface 21a is joined to the first surface 21a via the solder 30 and the first land 23a. If the base 11 of the nut 10 is joined to the first land 23a with sufficient strength, the entire second surface 11b may not be joined to the first land 23a.

  The first surface 11 a of the base 11 is flat and substantially parallel to the first land 23 a.

  The base 11 has a base body 11c in which the hole 13 is disposed, and a thin portion 14 whose thickness decreases so that the second surface 11b approaches the first surface 11a from the base body 11c side toward the peripheral portion of the base 11. Have. The thin portion 14 is formed at a portion of the base 11 of the nut 10 that extends outward from the base body 11 c. The thin portion 14 may be formed to extend directly outward from the shaft portion 12.

  The portion on the first surface 11 a side of the thin portion 14 is flat as shown in FIG. 2 (B). On the other hand, the portion on the second surface 11 b side of the thin portion 14 is inclined with respect to the first surface 11 a of the base 11. A portion on the second surface 11 b side of the thin portion 14 faces the first surface 21 a of the substrate 20 on which the first land 23 a is disposed, with the solder 30 interposed therebetween.

  The portion of the second surface 11b of the thin portion 14 is linearly inclined so as to expand outward with respect to the flat first land 23a, and a space R for holding the solder 30 is formed.

  The solder 30 is disposed between the second surface 11b of the base 11 and the first land 23a, and is disposed between a portion on the base 11 side in the longitudinal direction of the shaft 12 and the conductive portion 23b in the through hole. Be done.

  As a result, the nut 10 is mechanically and electrically joined to the first land 23 a and the conductive portion 23 b in the through hole via the solder 30 and fixed to the substrate 20.

  Between the end of the base 11 and the end of the first land 23a, an inclined portion 30a of the solder 30 is formed extending obliquely from the end of the base 11 toward the end of the base 11. The state of soldering between the nut 10 and the substrate 20 can be determined, for example, by visual inspection of the inclined portion 30a.

  As a forming material of the nut 10, for example, a metal having electrical conductivity such as an iron-based alloy can be used. Further, the surface of the nut 10 is preferably coated with a material having solder wettability such as tin plating from the viewpoint of improving the solder wettability.

  As a forming material of the substrate body 21, a resin having electrical insulation such as an epoxy resin can be used. As a forming material of the conductive portion 23, for example, a material having electrical conductivity and solder wettability such as copper can be used.

  The joint structure 1 described above is formed, for example, by soldering the nut 10 and the substrate 20 using a reflow method.

  At this time, since the space R is formed between the first land 23a and the portion of the thin portion 14 of the base 11 of the nut 10 on the second surface 11b side, the solder 30 forms the inclined portion 30a. A sufficient amount of solder can be held in this space R to perform soldering so as to have the slope 30a.

  Further, since the portion on the second surface 11 b side of the thin portion 14 is inclined so as to approach the first land 23 a from the outer side of the base 11 toward the center side, the thin portion 14 and the first land 23 a The distance between the points becomes narrower towards the inside. Since the flow resistance of the solder 30 in the molten state moving from the space R into the through hole 22 is increased, the amount of the solder 30 moving to the through hole 22 is regulated. As a result, excess solder is prevented from flowing between the outer surface of the shaft 12 and the through-hole conductive portion 23 b, and the solder is prevented from coming into the hole 13 in the shaft 12.

  As shown in FIG. 2B, the portion on the second surface 11b side of the thin portion 14 extends inward of the through hole 22 more than the end edge on the through hole 22 side of the first land 23a. It is preferable from the viewpoint of narrowing the gap between the thin portion 14 and the edge of the opening of the through hole 22 and increasing the flow resistance of the solder from the space R into the through hole 22.

  The bonding structure 1 described above is used, for example, to fix a bolt 40 having a base portion 41 and a shaft portion 42 to a substrate 20, as shown in FIG. By inserting the shaft portion 42 of the bolt 40 into the hole portion 13 of the nut 10 and screwing the nut 45 to the portion extending from the hole portion 13, the bolt 40 is coupled with the nut 10 and the washer 43 Are mechanically and electrically coupled to the substrate 20. Thereby, by connecting the lead wire 44 extending from the washer 43 to another electrical device (not shown), the electrical device can be grounded using the substrate 20.

  According to the bonding structure 1 of the present embodiment described above, since the inclined portion 30a is easily formed in the step of soldering the nut 10 and the substrate 20, bonding of the nut 10 to the substrate 20 is performed using an appearance inspection. It becomes easy to check the condition. Further, since the solder 30 can be prevented from coming into the hole portion 13 in the shaft portion 12, it is possible to prevent the generation of solder chips when the bolt is inserted into the hole portion 13.

  Next, another embodiment of a joint structure including the above-described nut will be described below with reference to FIGS. The detailed description of the first embodiment described above is applied as appropriate to the point that the other embodiments are not specifically described. Further, the same components are denoted by the same reference numerals.

  FIG. 6A is a cross-sectional view showing a second embodiment of the junction structure disclosed in the present specification, and corresponds to FIG. 2B of the first embodiment. FIG. 6 (B) is a plan view of the nut, and FIG. 6 (C) is a front view of the nut.

  In the bonding structure 1 of the present embodiment, the shape of the thin portion 14 is different from that of the first embodiment described above.

  In the bonding structure 1 of the present embodiment, the portion on the second surface 11 b side of the thin portion 14 has a step.

  The thickness of the portion of the second surface 11b of the thin portion 14 is reduced in a stepwise manner so as to approach the first surface 11a from the base main body 11c side outward. In the example shown in FIGS. 6A to 6C, the portion on the second surface 11b side of the thin portion 14 approaches the first surface 11a in two steps from the base main body 11c side outward. The space R is formed between the first land 23a and the first land 23a.

  According to the bonding structure 1 of the present embodiment described above, the same effect as that of the first embodiment described above is exhibited. Further, by adjusting the dimension of the step formed in the portion on the second surface 11 b side of the thin portion 14, it is easy to change the size or the shape of the space R.

  In addition, the part by the side of the 2nd surface 11b of thin part 14 may have a portion which inclines like a 1st embodiment mentioned above with a level difference.

  FIG. 7A is a cross-sectional view showing a third embodiment of the junction structure disclosed in the present specification, and corresponds to FIG. 2B of the first embodiment. FIG. 7 (B) is a front view of the nut.

  The joint structure 1 of the present embodiment is different from the first embodiment in the shape of the shaft 12 of the nut 10.

  The outer diameter of the shaft portion 12 of the shaft portion 12 of the nut 10 decreases from the base 11 side to the side opposite to the base 11, and has a tapered shape as a whole.

  In the through hole 22, the space Q formed between the outer surface of the shaft 12 and the conductive portion 23 b in the through hole has a shape that expands from the first surface 21 a side to the second surface 21 b side of the substrate 20. Have.

  The distance between the outer surface of the shaft 12 and the surface of the through-hole conductive portion 23b is, for example, about 0.1 to 0.2 mm.

  When the solder 30 in a molten state flows into the space Q between the outer surface of the shaft 12 and the surface of the through-hole conductive portion 23b, the solder 30 may receive a driving force by capillary force.

  The space Q has a shape expanding from the side of the first surface 21a of the substrate 20 toward the side of the second surface 21b, so that the molten solder 30 is moved by the capillary force toward the side of the second surface 21b. It is suppressed to receive force.

  As a result, the molten solder 30 is prevented from coming into the hole 13 in the shaft 12.

  According to the bonding structure 1 of the present embodiment described above, the same effect as that of the first embodiment described above is exhibited.

  The shaft portion 12 of the nut 10 may have a region with a constant dimension as in the first embodiment described above, together with the tapered shape.

  FIG. 8 (A) is a cross-sectional view showing a fourth embodiment of the junction structure disclosed in the present specification, and corresponds to FIG. 2 (B) of the first embodiment. FIG. 8 (B) is a front view of the nut.

  The joint structure 1 of the present embodiment is different from the first embodiment in the shape of the shaft 12 of the nut 10.

  The shaft portion 12 of the nut 10 of the present embodiment has a recess 12 a in which the outer surface of the shaft portion 12 is recessed inward.

  The recess 12 a is formed so as to close around the outer surface of the cylindrical shaft 12. As a result, the solder 30 in the molten state, which has been moved from the space R into the through hole 22, moves toward the second surface 21 b by capillary force at any position on the outer surface of the shaft 12. It is suppressed to receive.

  By providing the recess 12a, the space Q has a shape expanding from the side of the first surface 21a to the side of the second surface 21b of the substrate 20, as in the third embodiment described above. As a result, the molten solder 30 is suppressed from receiving a driving force that moves toward the second surface 21 b side, and the molten solder 30 turns into the hole 13 in the shaft 12. Is prevented.

  According to the bonding structure 1 of the present embodiment described above, the same effect as that of the first embodiment described above is exhibited.

  The recess 12 a may be provided on part of the outer surface of the shaft 12. In addition, a plurality of concave portions may be provided on the outer surface of the cylindrical shaft portion 12.

  FIG. 9 is a cross-sectional view showing a fifth embodiment of the junction structure disclosed in the present specification, and corresponds to FIG. 2 (B) of the first embodiment.

  In the bonding structure 1 of the present embodiment, the shape of the through hole 22 of the substrate 20 is different from that of the first embodiment described above.

  As described in the third embodiment, the solder 30 in the molten state moved from the space R into the through hole 22 is prevented from receiving a driving force that moves toward the second surface 21 b by capillary force. Preferably.

  From this viewpoint, in the third embodiment, the distance between the outer surface of the shaft portion 12 and the conductive portion 23b in the through hole is increased from the first surface 21a side of the substrate 20 toward the second surface 21b side. The

  Based on the same idea as this, in the present embodiment, the diameter of the through hole 22 increases from the side of the first surface 21a toward the side of the second surface 21b.

  As a result, the molten solder 30 is suppressed from receiving a driving force that moves toward the second surface 21 b side, and the molten solder 30 turns into the hole 13 in the shaft 12. Is prevented.

  According to the bonding structure 1 of the present embodiment described above, the same effect as that of the first embodiment described above is exhibited.

  In the present invention, the nut and the joint structure including the nut of the embodiment described above can be appropriately modified without departing from the spirit of the present invention. In addition, the constituent features of one embodiment can be appropriately applied to the other embodiments or the modifications.

  For example, in the bonding structure of the first embodiment described above, the surface of the through hole 22 of the substrate 20 may have a recess that is recessed inward. The recess is formed, for example, so as to close the surface of the through hole 22. As a result, the molten solder 30 is suppressed from receiving a driving force that moves toward the second surface 21 b side, and the molten solder 30 turns into the hole 13 in the shaft 12. Is prevented.

DESCRIPTION OF SYMBOLS 1 joint structure 10 nut 11 base 11a 1st surface 11b 2nd surface 11c base main body 12 axial part 12a recessed part 13 hole part 14 thin thickness part 20 board 21 board main body 21a 1st surface 21b 2nd surface 22 through hole 23 conductive part 23a 1st Reference Signs List 1 land 23b through-hole conductive portion 23c second land 23d extension 30 solder 30a slope 40 bolt 41 base 42 shaft 43 washer 44 conductor 45 nut

Claims (7)

A base having a first surface and a second surface provided opposite to the first surface;
An axial portion disposed on the second surface of the base and extending from the second surface to the opposite side of the first surface;
A hole which penetrates the base from the first surface side toward the second surface and extends at least to the inside of the shaft;
Equipped with
The base includes: a base body in which the hole is disposed; and a thin portion whose thickness decreases so that the second surface approaches the first surface from the base body side toward the periphery of the base. Have a nut.   The nut according to claim 1, wherein a portion on the second surface side of the thin portion has a step or is inclined with respect to the first surface.   The nut according to claim 1, wherein an outer diameter of the shaft portion decreases from the base side to the opposite side to the base.   The nut according to any one of claims 1 to 3, wherein the shaft portion has a recess in which the outer surface of the shaft portion is recessed inward. A base having a first surface and a second surface provided opposite to the first surface;
An axial portion disposed on the second surface of the base and extending from the second surface to the opposite side of the first surface;
A hole which penetrates the base from the first surface side toward the second surface and extends at least to the inside of the shaft;
Equipped with
The base includes: a base body in which the hole is disposed; and a thin portion whose thickness decreases so that the second surface approaches the first surface from the base body side toward the periphery of the base. Having a nut,
A substrate body having a third surface and a fourth surface;
A through hole which penetrates the substrate main body from the third surface to the fourth surface and into which the shaft portion can be inserted;
A substrate having
A solder for bonding the part of the second surface of the base or the part of the shaft and the substrate;
Equipped with
The joint structure in which the shaft portion is inserted into the through hole in a state in which the base is exposed on the third surface of the substrate.   The joint structure according to claim 5, wherein a distance between an outer surface of the shaft portion and a surface of the through hole increases from the third surface side toward the fourth surface side.   The bonding structure according to claim 6, wherein the diameter of the through hole increases from the third surface side toward the fourth surface side.

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