JP4638836B2 - Lug terminal and plate material mounting structure using lug terminal - Google Patents

Description

  The present invention belongs to the technical field of lug terminals.

In electronic devices, lug terminals are sometimes used to connect a ground pattern of a printed circuit board and a metal housing.
Japanese Patent Laid-Open No. 2005-339964 (Patent Document 1) discloses a screw mounting portion made of a metal plate and provided with an opening through which a screw is inserted, and a molten solder at the tip extending from the screw mounting portion. A first extending portion provided as a recess extending along the extending direction; a first extending portion extending from the screw mounting portion in parallel with the first extending portion; The lug terminal provided with two 2nd extension parts which are opposed to each other is disclosed.

The lug terminal disclosed in Patent Document 1 has a lug centered on the screw inserted through the opening of the screw mounting portion because the tip end portions of the first extension portion and the second extension portion are soldered to the printed circuit board. With respect to the moment to rotate the terminal, a large resistance force is exerted by the principle of the lever, and there is an effect that the torque strength at the time of screwing or loosening the screw is high.
JP 2005-339964 A

  However, in the case of the lug terminal disclosed in Patent Document 1, when the tip portions of the first and second extending portions are soldered to the printed circuit board, between the screw mounting portion that is not soldered and the printed circuit board, There is a slight gap. When tightening with a screw inserted into the opening of the screw mounting portion from this state, there is a risk that stress is applied to the fixed portion to cause distortion. This problem is not limited to the lug terminals disclosed in Patent Document 1, and is a problem common to conventional lug terminals.

The lug terminal according to claim 1 is a lug terminal made of a metal plate and surface-mounted on a printed circuit board by soldering.
A screw mounting portion provided with an opening for inserting a screw;
Two terminal pieces, one end of which is connected to the screw mounting portion and arranged in parallel to each other;
A stable holding piece having one end connected to the screw mounting portion and disposed between the two terminal pieces;
The tip portions of the two terminal pieces are fixed portions to which the lower surfaces are soldered, respectively.
The terminal piece is formed by reducing the cross-sectional area of the terminal piece or by bending the terminal piece at the end of the terminal piece that is connected to the screw mounting part, and the fixing part is fixed. It is characterized in that a deformation allowing portion is provided for allowing the mounting portion to be displaced toward the printed wiring board.

The lug terminal is made of a conductive metal plate, but a part (or all) of the surface may be plated in order to improve the adhesion of solder.
The screw attachment portion may be closed in a ring shape, or may be a shape in which a part such as a U shape or a C shape is cleaved.

  Two terminal pieces are connected to each other at one end of the screw mounting portion and extend in parallel to each other (the extending direction is aligned). The front end portions of these terminal pieces are fixed portions to which the lower surface is soldered, and the end portions connected to the screw mounting portions are provided with deformation-permitting portions that are each formed with a reduced width by a notch.

The deformation allowing portion can be formed by narrowing a part of the terminal piece by a notch or a hole, or by reducing the thickness of a part of the terminal piece. That is, it can be formed by providing a notch or a hole, or by reducing the plate thickness and making the cross-sectional area along the width direction of the terminal piece smaller than the adjacent portion. It can also be formed by bending the terminal piece into a wave shape. That is, before Symbol deformation allowing portion, reduce the cross sectional area of the terminal pieces may be a structure which is formed by bending the terminal strip.

One end of a stable holding piece disposed between the two terminal pieces is connected to the screw mounting portion.
The lug terminal is attached to a printed circuit board with a fixed portion provided at the tip of the terminal piece soldered to the lower surface. Since the screw mounting portion and the stable holding piece are not soldered, a gap is formed between the screw mounting portion and the printed board according to the thickness of the solder.

  Subsequently, when the screw is inserted into the opening of the screw mounting portion and tightened, the screw mounting portion is pressed by the screw and pressed against the printed board. That is, the screw mounting portion is displaced toward the printed board. Further, the stable holding piece is also displaced with the displacement of the screw mounting portion.

On the other hand, since the fixed portion is soldered on the lower surface, it does not follow the displacement of the screw mounting portion.
Accordingly, a stress acts between the fixed portion and the screw mounting portion. The portion between the fixed portion and the screw mounting portion is provided with a deformation allowing portion formed by narrowing the width by a notch, and easily deforms when tightening with the above-described screw. The stable holding piece is displaced with little resistance. As a result, the lower surface of the screw mounting portion and the stable holding piece firmly contacts the surface of the printed circuit board. Such a state where the surfaces are in close contact with each other is called a landing surface. And the screw attachment part and stable holding piece which contacted the surface of the printed circuit board stabilize the attachment state of a lug terminal.

  Further, since the deformation permitting portion is easily deformed, it is possible to prevent stress accompanying tightening with screws from reaching the fixed portion, and to prevent the fixed portion from being distorted by the action of such stress. This also prevents the quality of soldering from being degraded.

The above effect can be ensured by soldering only the fixed portion to the printed circuit board during the surface mounting.
Lug of the third aspect, wherein the lug of claim 1 or 2, wherein, when tightened by a screw which is inserted through the opening of the threaded mounting portion of said lug which is surface mounted on the printed circuit board, said screw As described above, the deformation allowing portion can be bent and deformed by the pressing force applied by the screw acting on the mounting portion, and the screw mounting portion and the stable holding piece can be displaced to contact the printed circuit board. The screw mounting part and the stable holding piece that are attached to the surface of the printed circuit board can stabilize the mounting state of the lug terminal, and the deformation permitting part is easily deformed, so that it is fixed by the action of the stress associated with screw tightening. This prevents the portion from being distorted and prevents the quality of soldering from deteriorating.

The lug terminal according to claim 4 is:
The lug terminal according to claim 1 or 2 ,
A protrusion is provided on the lower surface of the stable holding piece at a position closer to the fixing part than a band-like region located between the deformation allowing parts of the two terminal pieces.

In this lug terminal, a protrusion is provided on the lower surface of the stable holding piece. The position of the protrusion is on the fixed part side of the band-like region located between the deformation-permitting parts of both terminal pieces.
As described above, when the terminal piece of the lug terminal is soldered to the printed circuit board and then screwed into the opening of the screw mounting portion and tightened, the screw mounting portion is pressed by the screw and is made to contact the printed circuit board.

  About a stable holding piece, a connection part with a screw attachment part follows the screw attachment part, and is displaced in the direction which contacts a printed circuit board. However, since there is a protrusion on the lower surface, the portion on the tip side of the protrusion is oscillated and displaced in a direction away from the printed board with the protrusion as a fulcrum. That is, the stable holding piece is displaced in a seesaw shape.

  When the screw mounting portion contacts the printed circuit board, the above-described displacement of the stable holding piece is maximized. Therefore, the degree of tightening by the screw can be understood by looking up the displacement of the stable holding piece on the tip side.

  Further, after being attached to the printed board, the heat conducted from the printed board to the lug terminal can be radiated from the stable holding piece to the air. That is, the stable holding piece also functions as a heat sink.

The lug terminal according to claim 5 is the lug terminal according to claim 4 , wherein the protrusion is provided at a position closer to the deformation-permitting portion side than a belt-like region located between the fixing portions. To do.

If the position of the protrusion is closer to the tip of the stable holding piece, the above-mentioned amount of jumping is relatively small, but if it is in the range of claim 5 , there is no fear that the amount of jumping will be too small.

The lug terminals according to claims 1 to 5 can also be used for attaching a conductive plate material to a printed circuit board. That is, the plate member mounting structure according to claim 6 .
The plate member mounting structure according to claim 6 is a screw in which the lug terminal according to any one of claims 1 to 5 is mounted on the surface, and then a conductive plate material is placed on the lug terminal and inserted into the opening. In this case, the plate material and the printed circuit board can be electrically connected via the lug terminal. In addition, this board | plate material may be a part of parts attached to a printed circuit board like the nail | claw-shaped fixed piece protruded from the side surface of the shield box, for example.

Next, embodiments of the present invention will be described based on examples of the present invention. The present invention is not limited to the following examples and the like, and it goes without saying that the present invention can be implemented in various ways without departing from the gist of the present invention.
[Example 1]
The lug terminal 10 of this embodiment has the shape shown in FIG. 1 and is subjected to copper base plating (film thickness 1 μm) and tin finish plating (film thickness 1 to 3 μm) on tough pitch copper (plate thickness 0.3 mm). It is manufactured with a metal plate.

As shown in FIG. 1, the lug terminal 10 is provided with a U-shaped opening 12 through which a screw is inserted, and a peripheral portion thereof is a screw mounting portion 14.
A substantially rectangular stable holding piece 16 extends from the screw attachment portion 14 along the center line C (indicated by a one-dot chain line) of the opening 12. A convex portion 17 is provided at the tip of the stable holding piece 16.

Two terminal pieces 20 are extended from the screw mounting portion 14 in parallel with the stable holding piece 16.
In the vicinity of the connection portion of the terminal piece 20 with the screw mounting portion 14, notches 22 a and 22 b that are paired on the inner side and the outer side are provided, and the deformation allowing portion 22 is formed as a portion whose width is narrowed by these. Yes.

In addition, notches 23a, 23b, 24a, and 24b that form a pair on the inner side and the outer side are provided on the distal end side of the terminal piece 20 as well as the notches 22a and 22b.
The notches 23a and 23b are provided to define the fixing portion 24, and the distal end side becomes the fixing portion 24 from the convex portion between the notches 23a and 23b and the notches 24a and 24b.

Further, a recess 25 for discriminating the front and back of the lug terminal 10 is also provided.
As shown in the figure, the two terminal pieces 20 are opposed to each other with the stable holding piece 16 therebetween.

Next, surface mounting of the lug terminal 10 will be described.
As shown in FIG. 2, screw holes 32 corresponding to the openings 12 are formed in the printed circuit board 30 on which the lug terminals 10 are surface-mounted. The lug terminal 10 is surface-mounted on the printed circuit board 30 by soldering the terminal pieces 20 onto a ground pattern (not shown) with solder 33. This mounting operation is in accordance with a publicly known method. The automatic mounting machine sucks the central portion 31 of the lug terminal 10 and places it on the printed circuit board 30 to which the solder cream is applied, and then places the printed circuit board 30 in a reflow furnace. Reflow soldering is performed.

  In the state where the stable holding piece 16 is not soldered and the two terminal pieces 20 are soldered to the printed circuit board 30, as shown in FIG. And is not in contact with the printed circuit board 30.

In this way, after the lug terminal 10 is mounted on the printed circuit board 30, the lug terminal 10 and the printed circuit board 30 are fixed to the housing by the screw 34 inserted through the opening 12.
The deformation of the lug terminal 10 at the time of fixing with the screw 34 will be described with reference to FIG. 3, but FIG. 3 shows, for example, that the thickness of the solder 33 is thicker than the actual thickness in order to easily explain the deformation of the lug terminal 10. There are exaggerated parts such as display.

  As shown in FIG. 3, the screw 34 is inserted into the opening 12 and tightened. After the seating surface of the screw 34 comes into contact with the screw mounting portion 14 of the lug terminal 10 (a), the screw mounting portion 14 is pressed by the seating surface of the screw 34 and pressed toward the printed circuit board 30 along with the tightening. Sink (b). Further, the stable holding piece 16 is also displaced toward the printed circuit board 30 with the displacement of the screw mounting portion 14.

On the other hand, since the lower surface of the fixing portion 24 is soldered, it does not follow the displacement of the screw mounting portion 14.
Accordingly, a stress acts between the fixing portion 24 and the screw mounting portion 14. This portion is provided with a deformation allowing portion 22 formed by narrowing the width by notches 22a and 22b, and is easily deformed when tightening with the above-described screw 34, so that the screw mounting portion 14 and the stable holding piece 16 are Displacement is performed with little resistance. As a result, the screw attachment portion 14 and the stable holding piece 16 are firmly attached to the surface of the printed circuit board 30, and the attachment state of the lug terminal 10 is stabilized.

Moreover, since the deformation | transformation permission part 22 deform | transforms easily, it can prevent that the stress accompanying the clamping | tightening with the screw | thread 34 reaches to the fixing | fixed part 24, and prevents the fixing | fixed part 24 from distorting by the effect | action of such stress. This also prevents the quality of soldering from being degraded.
[Example 2]
An example in which a protrusion is provided on the lower surface of the stable holding piece will be described as a second embodiment. In addition, since many parts are common with Example 1, about these, the same code | symbol as Example 1 is used, and description is abbreviate | omitted.

  As shown in FIG. 4, the stable holding piece 16 of the lug terminal 10a of the present embodiment is provided with a linear protrusion 26 along the width direction thereof. The positions of the protrusions 26 are on the fixed portion 24 side of the straight line L that connects the bottoms of the notches 22a of the terminal pieces 20 (the narrowest width portions of the deformation-permitting portion 22), and is a belt-like shape located between the notches 22a. Is provided on the fixed portion 24 side of the region, and on the straight line L side of the notches 23a and 23b for defining the fixed portion 24.

The surface mounting of the lug terminal 10a is performed in the same manner as in the first embodiment.
After the lug terminal 10a is mounted on the printed circuit board 30, the deformation of the lug terminal 10a when the lug terminal 10a is fixed to the printed circuit board 30 with the screw 34 inserted through the opening 12 will be described with reference to FIG. 5 is exaggerated in part as in FIG.

  As shown in FIG. 5, when the screw 34 is inserted into the opening 12 and tightened and tightening is continued after the seat surface of the screw 34 abuts (a) the screw mounting portion 14 of the lug terminal 10a, 14 is pushed to the printed circuit board 30 side and sinks and contacts the printed circuit board 30 (b).

Since the terminal piece 20 is soldered, it does not follow the displacement of the screw mounting portion 14 toward the printed board 30 side.
As for the stable holding piece 16, the vicinity of the connecting portion with the screw mounting portion 14 follows the displacement of the above-described screw mounting portion 14 toward the printed circuit board 30. However, since the protrusion 26 is provided on the lower surface, The tip side of the protrusion 26 is oscillated and displaced in a direction away from the printed circuit board 30 with the protrusion 26 as a fulcrum. That is, the stable holding piece 16 is displaced in a seesaw shape with the protrusion 26 as a fulcrum (b). Therefore, the degree of tightening by the screw 34 can be understood by looking at the displacement of the stable holding piece 16 in the form of jumping up.

  Further, since the stable holding piece 16 is separated from the printed board 30, the heat conducted from the printed board 30 through the terminal piece 20 and the screw mounting portion 14 can be radiated from the stable holding piece 16 into the air. That is, the stable holding piece 16 also functions as a heat sink.

  In addition, since the deformation | transformation permission part 22 deform | transforms easily at the time of the clamping | tightening with the screw 34, the displacement of the screw attachment part 14 and the stable holding piece 16 is performed with little resistance, and the screw attachment part 14 contacts the surface of the printed circuit board 30 firmly. And it is the same as that of Example 1 to stabilize the attachment state of the lug terminal 10a.

Moreover, since the deformation | transformation permission part 22 deform | transforms easily, it can prevent that the stress accompanying the clamping | tightening with the screw | thread 34 reaches to the fixing | fixed part 24, and prevents the fixing | fixed part 24 from distorting by the effect | action of such stress. This also prevents the soldering quality from being degraded, as in the first embodiment.
[Modification of screw mounting part]
In the first and second embodiments, the U-shaped opening 12 is adopted. However, as shown in FIG. 6, the lug terminal 10b (opening 12a and screw mounting portion) provided with a closed opening 12a and an annular screw mounting portion 14a. However, the same effects as in Example 1 can be obtained. Furthermore, the strength of the screw attachment portion 14a is increased with this shape.
[Modification of protrusion]
In the second embodiment, the linear protrusion 26 is provided on the lower surface of the stable holding piece 16, but this may be a circular (hemispherical) protrusion 26a like a lug terminal 10c shown in FIG. A plurality of such protrusions 26a may be provided as in the lug terminal 10d shown in FIG.
[Deformation example of deformation allowable part]
In the first and second embodiments, the terminal piece 20 is provided with the notches 22a and 22b to form the deformation allowing portion 22, but the configuration shown in FIG.

FIG. 8A shows an example in which a narrow portion is formed in the terminal piece 20 by providing a hole 35 in the terminal piece 20, and this is used as a deformation allowing portion 36. FIG. 8B is an example in which a thin portion is formed on the terminal piece 20 by, for example, dents or cutting, and these are used as the deformation permitting portions 37 and 38. FIG. 8C shows an example in which the deformation permitting portions 39 and 40 are formed by bending a part of the terminal piece 20.
[Combination with shield box]
Since the lug terminal 10 and the lug terminal 10b have a substantially flat structure, the lug terminal 10 and the lug terminal 10b can be fixed to the printed circuit board 30 and then put on a shield box and fastened with screws 34. An example of this will be described with reference to FIG.

As shown in FIG. 9, the metal shield box 40 is provided with four fixed pieces 41 (corresponding to the plate material of claim 4). Each fixing piece 41 is provided with a hole 42 through which the screw 34 is passed.

As shown in FIG. 9A, the shield box 40 is placed on the printed circuit board 30 with the fixed pieces 41 placed on the lug terminals 10. At this time, the shield box 40 is aligned so that the holes 42 of the respective fixing pieces 41 are positioned on the opening 12 of the lug terminal 10 which is below.

  If the screw 34 is inserted and tightened into the hole 42 of the fixed piece 41 and the opening 12 of the lug terminal 10, the fixed piece 41, that is, the shield box 40 and the printed circuit board 30 can be conducted through the lug terminal 10. .

  Further, when the protrusions 26 and 26a are provided on the lower surface of the stable holding piece 16, like the lug terminals 10a, 10c, and 10d of the modified example shown in the second embodiment and FIGS. 7A and 7B, FIG. As shown in FIG. 10, when the screw 34 is inserted and tightened into the hole 42 of the fixing piece 41 and the opening 12 of the lug terminal 10, the lug terminal 10a is deformed in the same manner as in the second embodiment (see FIG. 5). The fixed piece 41 is also deformed as shown in the figure because the terminal piece 20 and the solder 33 are supported. 10 is exaggerated for easy understanding of the deformation of the lug terminal 10a and the fixing piece 41, as in FIGS.

If the screws 34 are fastened together as described above, the shield box 40 can be electrically connected to the ground pattern of the printed circuit board 30 via the lug terminal 10a.
When the screws 34 are tightened together, the tip of the stable holding piece 16 is displaced in a jumping manner as described with reference to FIG. 5, but this is in contact with the lower surface of the fixed piece 41.

  By the way, even if the fixing piece 41 is fixed by the screw 34 as described above, the central portion (box-shaped portion) of the shield box 40 is not fixed, so that it is slightly moved. When vibration is applied to the shield box 40 in this state, the entire shield box 40 is finely moved and finely moved even at the contact portion between the stable holding piece 16 and the fixed piece 41. Since the positional relationship shown in FIG. 10 is obtained when this fine movement occurs, the contact is rubbed and a self-cleaning effect occurs at the contact portion between the two. Therefore, when the lug terminal 10a having the stable holding piece 16 provided with the protrusion 26 is used, the shielding effect is sustained over a long period of time compared to the case having no member corresponding to the stable holding piece 16.

The front view (a) and right view (b) of the lug terminal of Example 1. FIG. The top view of the state which mounted the lug terminal of Example 1 on the printed circuit board. Explanatory drawing at the time of screwing the lug terminal of Example 1. FIG. The front view (a) and right view (b) of the lug terminal of Example 2. FIG. Explanatory drawing at the time of screwing the lug terminal of Example 2. FIG. Explanatory drawing of the modification of a screw attachment part ((a) is a front view, (b) is a right view). Explanatory drawing of the modification of protrusion ((a) is a front view of a 1st example, (b) is a front view of a 2nd example). Explanatory drawing of the modification of a deformation | transformation permission part ((a) is a hole, (b) is thin wall, (c) is bending). Explanatory drawing of the example which fixes a shield box using the lug terminal of Example 1. FIG. Explanatory drawing when fastening the lug terminal and shield box of Example 2 together.

Explanation of symbols

10, 10a, 10b, 10c, 10d ... lug terminal,
12, 12a ... opening,
14, 14a... Screw mounting portion,
16 ... stable holding piece,
20: Terminal piece,
22 ... Deformation allowable part,
22a, 22b ... notches,
26, 26a ... projections,
30 ... printed circuit board,
33 ... Solder.

Claims (6)

In the lug terminal which consists of a metal plate and is surface-mounted on the printed circuit board by soldering,
A screw mounting portion provided with an opening for inserting a screw;
Two terminal pieces, one end of which is connected to the screw mounting portion and arranged in parallel to each other;
A stable holding piece having one end connected to the screw mounting portion and disposed between the two terminal pieces;
The tip portions of the two terminal pieces are fixed portions to which the lower surfaces are soldered, respectively.
The terminal piece is formed by reducing the cross-sectional area of the terminal piece or by bending the terminal piece at the end of the terminal piece that is connected to the screw mounting part, and the fixing part is fixed. A lug terminal comprising a deformation allowing portion for allowing a displacement of the mounting portion toward the printed wiring board. The lug terminal according to claim 1, wherein only the fixed portion is soldered to the printed circuit board during the surface mounting. The lug terminal according to claim 1 or 2 ,
When tightened with a screw inserted through the opening of the screw mounting portion of the lug terminal surface-mounted on the printed circuit board,
The deformation-allowing portion can be bent and deformed by the pressing force of the screw acting on the screw mounting portion, and the screw mounting portion and the stable holding piece can be displaced to be attached to the printed circuit board. Lug terminal. The lug terminal according to claim 1 or 2 ,
A lug terminal, wherein a protrusion is provided on a lower surface of the stable holding piece at a position closer to the fixing portion than a band-like region located between the deformation allowing portions of the two terminal pieces. The lug terminal according to claim 4 ,
The lug terminal, wherein the protrusion is provided at a position closer to the deformation-permitting portion than a band-like region located between the fixing portions. After the surface mounting of the lug terminal according to any one of claims 1 to 5, an electroconductive plate material is placed on the lug terminal, and the plate material is fastened together with a screw inserted through the opening. A plate mounting structure using lug terminals.

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