JP3408777B2 - Terminal - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a bottom plate which is placed on one or a pair of pads (also referred to as lands) formed on a printed wiring board via cream solder. The present invention relates to a terminal in which a soldering portion is formed on a portion of a bottom plate corresponding to a pad. For example, the one related to the ground terminal, which is formed on the printed wiring board.
Print the cream solder on the pair of ground pads, place the bottom plate of the ground terminal on it, and heat and melt the cream solder in the reflow bath to solder and fix the soldering part of the bottom plate to the pad, It is used when the shield case is electrically connected to the ground pad on the printed wiring board by pressing the shield case into contact with the contact portion of the ground terminal.

[0002]

2. Description of the Related Art Conventionally, a terminal having a bottom plate placed on a pair of pads via cream solder has a soldering portion formed on the bottom plate corresponding to the pair of pads. The vertical bisector of the line segment connecting the centers of these two soldering portions was formed in an asymmetric shape.

[0003]

As described above, in the conventional terminal, the two soldering portions formed on the bottom plate corresponding to the pair of pads are formed in an asymmetrical shape. When the cream solder is heated and melted in the bath to be soldered, there is a problem that the solder connection portion and the pad are likely to be misaligned. Further, since the shape of the solder fillet (solder heap) formed between the soldering portion and the pad is small, there is a problem that the soldering strength is weak.

The present invention has been made to solve the above-mentioned problems, and suppresses the positional deviation between the soldering portion and the pad of the terminal to be soldered by heating and melting the cream solder, and at the same time, improves the soldering strength. The purpose is to improve.

[0005]

According to a first aspect of the present invention, there is provided a bottom plate which is placed on a pair of pads formed on a printed wiring board via cream solder.
In a terminal in which a soldering portion is formed at a portion corresponding to each pair of pads, the two soldering portions are symmetrical with respect to a vertical bisector Z of a line segment connecting the centers O1 and O2 of the two soldering portions. A through hole having a shape is formed, and the minimum inner wall surface interval K1 between the two through holes is formed to be substantially equal to the minimum outer wall surface interval P1 between the pair of pads. In such a configuration, the terminals and the pad are displaced during melting of the cream solder for some reason, and a part of the inner wall surface of one of the two through holes having the minimum inner wall surface spacing of K1 is displaced outward from the outer wall surface of the pad. The molten cream solder circulates along the inner wall surface of the misaligned inner wall surface, and the force resulting from the surface tension of the molten cream solder acts in the direction of eliminating the misalignment with respect to the bottom plate, and the misalignment of the terminals and pads is prevented. Suppress. By suppressing the positional deviation between the terminals and the pads, a solder fillet of the molten cream solder is formed on most of the inner wall surface of the through hole, and the shape of the solder fillet is increased to improve the soldering strength.

According to the second aspect of the present invention, there is provided a bottom plate placed on the pair of pads formed on the printed wiring board via the cream solder, and each bottom plate is provided with the bottom plate. In the terminal in which the soldering portion is formed in the part where the two soldering portions are formed, the center O of the two soldering portions is
A through hole having a symmetrical shape with respect to a perpendicular bisector Z connecting the line segment connecting the first and O2 is formed, and a maximum inner wall surface interval K2 between the two through holes is defined as a maximum outer wall surface interval P2 between the pair of pads. It is characterized in that they are formed almost equally. In such a configuration, the terminals and the pad are displaced during melting of the cream solder for some reason, and a part of one inner wall surface of one of the two through holes having the maximum inner wall surface spacing of K2 is displaced outward from the outer wall surface of the pad. The molten cream solder circulates along the inner wall surface of the misaligned inner wall surface, and the force resulting from the surface tension of the molten cream solder acts in the direction of eliminating the misalignment with respect to the bottom plate, and the misalignment of the terminals and pads is prevented. Suppress. By suppressing the displacement of the terminals and pads, a solder fillet of molten cream solder is formed on most of the inner wall surface of the through hole,
The shape of the solder fillet becomes large and the soldering strength is improved.

According to a third aspect of the present invention, in the first or second aspect of the invention, in order to further improve the positional deviation suppressing effect and the soldering strength, a pair of pads are arranged in the X-axis direction parallel to the arrangement direction. A right-angled quadrangular pad 2 having a length Lx and a length Ly (Lx ≦ Ly) in the Y-axis direction perpendicular to the array direction.
The length W in the direction perpendicular to the straight line passing through the centers O1 and O2 of the soldering portion is shorter than Ly, and the relative length is parallel to the straight line passing through the centers O1 and O2 of the soldering portion. A notch is formed on the facing outer side, and the shape of this notch is formed symmetrically with respect to a straight line passing through the centers O1 and O2.

According to a fourth aspect of the present invention, in the first, second or third aspect of the invention, a pair of pads are provided in order to improve the positional deviation suppressing effect and the soldering strength by the soldering portion having a simple structure. The length in the X-axis direction parallel to the array direction is L
x, the length in the Y-axis direction perpendicular to the array direction is Ly (Lx
≦ Ly) composed of two right-angled quadrangular pads, and the two through-holes are circular through-holes 2 having a diameter R substantially equal to Lx.
Composed of individual pieces.

According to a fifth aspect of the present invention, in the first, second or third aspect of the invention, a pair of pads are provided in order to improve the positional deviation suppressing effect and the soldering strength by the soldering portion having a simple structure. The length in the X-axis direction parallel to the array direction is L
x, the length in the Y-axis direction perpendicular to the array direction is Ly (Lx
≤ Ly) composed of two right-angled quadrangular pads, and the two through-holes are square through-holes 2 with one side being approximately equal to Lx.
Composed of individual pieces.

[0010]

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. 1 and 2 show an embodiment of a ground terminal (an example of a terminal) according to the present invention.
In FIG. 1, (a) is a plan view, (b) is a front view, and (c).
2 is a bottom view, FIG. 2A is a left side view of FIG. 1B, and FIG. 2B is a right side view of FIG. 1B. In these figures, 10 is a printed wiring board, 12, 14 Is a pair of ground pads (hereinafter simply referred to as pads) formed on the printed wiring board 10, 16 and 18 are cream solder printed on the pads 12 and 14, and 20 is the cream solder. 16, the pad 12 through
14 is a grounding terminal placed on 14.

The pads 12 and 14 have a length Lx (eg, Lx = 0.8 m) in the X-axis direction parallel to the arrangement direction.
m), and the length in the Y-axis direction perpendicular to the arrangement direction is Ly (for example, Ly = 1.1 mm) (Ly> Lx), and the rectangular shape is formed. The minimum outer wall surface distance between the pads 12 and 14 is P1 (for example, P1 = 0.8 mm), and the maximum outer wall surface distance between the pads 12 and 14 is P2.
(For example, P2 = 2.4 mm).

The ground terminal 20 is a horizontal rectangular conductive plate having a plate width W (for example, W = 1.0 mm, W <Ly) (for example, a rectangular conductive plate made of phosphor bronze and having a plate thickness of 0.1 mm). ), A bottom plate 22 formed by (1), a folded portion 24 integrally provided on one end side of the bottom plate 22, and a contact portion 26 integrally provided at the tip of the folded portion 24. .

Solder portions 32 and 34 are formed on portions of the bottom plate 22 corresponding to the pads 12 and 14, respectively. The soldering portions 32 and 34 have a diameter R (R≈L
The circular through holes 36 and 38 of x) are formed. The center of the through holes 36 and 38 is the soldering portion 3
It is formed so as to coincide with centers O1 and O2 of 2, 34.
Therefore, as shown in FIG. 1C, the direction of a straight line passing through the centers O1 and O2 is the U-axis direction, and the perpendicular bisector of the line segment connecting the centers O1 and O2 is Z, and the vertical bisector is Assuming that the direction of Z is the V-axis direction, the through holes 36 and 38 have vertical bisectors Z.
The shape is symmetrical with respect to. Therefore, when the soldering portions 32 and 34 of the ground terminal 20 are positioned and placed on the pads 12 and 14, FIGS.
, The U axis coincides with the X axis, the V axis coincides with the Y axis, and the minimum inner wall surface interval K1 between the through holes 32 and 34 becomes the same as P1 (K1 = P1).
The maximum inner wall surface distance K2 between 2 and 34 is the same as P2 (K2
= P2).

Notches 40 to 54 are formed on the outer sides of the bottom plate 22 which face each other in the U-axis direction, and the notches 40 and 42 are formed on one of the outer sides (the upper side in FIG. 1C). Four
4, 46 and the notches 48, 50, 52, 54 formed on the other outer side (lower side in FIG. 1C) are formed in symmetrical shapes with respect to the U axis. The notches 40, 4
Part of 2, 48, 50 (about 1/4 in area) is located at the four corners of the soldering part 32, and the notches 40, 48 and the notches 42, 50 are on the V-axis passing through the center O1. The cutouts 44, 46, 5 are formed in a symmetrical shape with respect to parallel lines.
A part (about 1/4 of the area) of 2, 54 is located at the four corners of the soldering portion 34, and the notches 44, 52 and the notch 4 are formed.
6, 54 are formed in a symmetrical shape with respect to a line parallel to the V-axis line passing through the center O2. Therefore, the soldering portions 32 and 34 have a shape that is symmetrical with respect to the centers O1 and O2 in the front-rear direction (vertical left-right symmetry in FIG. 1C).

Next, the operation of the above embodiment will be described with reference to FIG.
(B) will be described together. (1) First, the cream solder 16 or 18 is printed on the pads 12 or 14 formed on the printed wiring board 10 by using a cream solder printing machine or the like, and the component soldering machine or the like is used thereon to reduce the size and weight. The ground terminal 20 is placed and brought into a state as shown in FIGS. Next, the cream solders 16 and 18 are heated and melted by using a reflow bath or the like, and the soldering portions 32 and 34 formed on the bottom plate 22 of the ground terminal 20 are soldered and fixed to the ground pads 12 and 14. At this time, the soldering parts 32, 3 of the ground terminal 20
If there is no displacement between 4 and pads 12 and 14,
As shown in FIG. 3B, the molten cream solder 16a, 18a is formed by uniformly and uniformly adhering to the inner wall surfaces of the through holes 36, 38, and after cooling, is formed on the inner wall surfaces of the through holes 36, 38. Solder fillets having substantially the same shape are formed, and high soldering strength can be obtained. In FIG. 3B, in order to simplify the illustration, the soldering parts 32 and 34 and the pads 12 and 1
Molten cream solder 16a, 18 interposed between the opposing surfaces of No. 4
Illustration of a is omitted. Further, the notches 40, 42, 48, 50 of the ground terminal 20 and the notches 44, 46, 52,
Solder fillets (not shown) of the molten cream solders 16a and 18a are also formed in the portions of 54 located at the four corners of the soldering portions 32 and 34 to improve the soldering strength.

(2) The cream solder 16 or 18 is not attached due to some cause such as a misplacement of the ground terminal 20 due to a component mounting machine, an imbalance of preheating in the reflow tank, heating, or movement of the ground terminal 20 during melting. During heating and melting, as shown in FIG. 3A, the ground terminal 20 and the pads 12, 1
4, a positional deviation in the left-right direction occurs, and the through holes 36, 38
When the right side portion of the inner wall surface of the pad shifts outward from the outer wall surfaces of the pads 12 and 14, the ground terminal 20 receives a leftward force indicated by an arrow in the figure by the force caused by the surface tension of the molten cream solder 16a and 18a. Then, the position shifts to the position shown in FIG. This is the through holes 36, 38.
It is considered that when the right side portion of the inner wall surface of the plate shifts to the right side from the outer wall surfaces of the pads 12 and 14, the molten cream solder 16a, 18a wraps around the inner wall surface of the shifted inner wall portion. Further, as shown in FIG. 3B, when there is no positional deviation between the ground terminal 20 and the pads 12 and 14, the molten cream solders 16a and 18a are
Since the inner wall surfaces of the through-holes 36 and 38 are evenly attached, the shape of the solder fillet formed over the inner wall surfaces of the through-holes 36 and 38 and the pads 12 and 14 becomes large as a whole. The attachment strength increases.

(3) Further, as shown in FIG. 3 (a), when the ground terminal 20 and the pads 12, 14 are displaced in the left-right direction, they are attached to the notches 40, 48 and the notches 42, 50. The amount of the molten cream solder 16a to be unbalanced becomes unbalanced, and the amount of the molten cream solder 18a attached to the notches 44 and 52 and the notches 46 and 54 becomes unbalanced, which is caused by the surface tension of the molten cream solder 16a and 18a. Pad 12 of the soldering parts 32 and 34,
The displacement with respect to 14 is suppressed. Further, since the solder fillet is formed across the notches 40 to 54 of the ground terminal 20 and the pads 12 and 14, the shape of the solder fillet becomes larger and the soldering strength is improved as compared with the case where the notches 40 to 54 are not provided. Increase.

(4) Also, although not shown, the position between the ground terminal 20 and the pads 12 and 14 in the front-back direction (vertical direction in FIG. 1C) during heating and melting of the cream solders 16 and 18. When the displacement occurs, the amounts of the molten cream solder 16a attached to the notches 40, 42 and the notches 48, 50 become unbalanced, and the molten cream solder 18a attached to the notches 44, 46 and the notches 52, 54. Becomes unbalanced, and the displacement of the soldering portions 32, 34 with respect to the pads 12, 14 is suppressed by the force resulting from the surface tension of the molten cream solder 16a, 18a.

(5) The soldering portion 3 of the ground terminal 20 is obtained by cooling and solidifying the molten cream solder 16a, 18a.
After soldering 2 and 34 to the pads 12 and 14, a shield case (not shown) is brought into pressure contact with the contact portion 26 of the ground terminal 20, and the elastic force of the folded portion 24 makes the contact portion 26 into a shielded case. By making elastic contact, the shield case is electrically connected to the ground pattern of the printed wiring board 10 via the ground terminal 20 and the pads 12 and 14.

In the above embodiment, the diameter R of the through hole formed in the two soldering portions of the terminal is set to the pad size in order to improve the positional deviation suppressing effect and the soldering strength by the soldering portion having a simple structure. Equal to the length Lx in the X-axis direction (R =
Lx), and the minimum inner wall surface distance between the two through holes at the time of positioning is the same as the minimum outer wall surface distance between the pair of pads (K1
= P1), the maximum inner wall surface distance between the two through holes is equal to the maximum outer wall surface distance between the pair of pads (K
2 = P2), the present invention is not limited to this, and the through hole formed in the two soldering portions is perpendicular to the line segment connecting the centers O1 and O2 of the two soldering portions. The shape is symmetrical with respect to the bisector Z, and the minimum inner wall surface distance between the two through holes is made equal to the minimum outer wall surface distance between the pair of pads, or the maximum inner wall surface distance between the two through holes is increased. It can be used when the inner wall surface interval is formed to be substantially equal to the maximum outer wall surface interval between the pair of pads.

FIG. 4 shows an example in which the minimum inner wall surface interval between the two through holes is made equal to the minimum outer wall surface interval between the pair of pads. In FIG. 4, the same parts as those in FIG. 1 are described. Is omitted. In FIG. 4, 20a is a ground terminal,
22a is a bottom plate, 32a and 34a are soldering parts, 36a,
38a is a through hole having a diameter r1 (r1 <Lx), and the centers of the through holes 36a and 38a are the soldering portions 32a and 34a.
It does not coincide with the centers O1 and O2 of a. The through hole 36a,
The minimum inner wall surface spacing K1 between the 38a is
Although it is formed to be equal to the minimum outer wall surface spacing P1 between the two pads 14, 14, the maximum inner wall surface spacing K2a is set to a pair of pads 12,14.
It is not equal to the maximum outer wall surface interval P2 between them.

Next, the schematic operation of FIG. 4 will be described with reference to FIG. (1) As long as the soldering portions 32a, 34a of the ground terminal 20a and the pads 12, 14 are not displaced, the molten cream solders 16a, 18a are placed in the through holes 36a, 38a as shown in FIG. 5B. It is formed by uniformly and uniformly adhering to the wall surface, and after cooling, a solder fillet having substantially the same shape is formed on the inner wall surfaces of the through holes 36a and 38a, and a large soldering strength is obtained. Further, the notches 40, 42, 48, 50 and the notches 44, 46, 5 of the ground terminal 20a.
Solder fillets (not shown) of the molten cream solders 16a and 18a are also formed on the portions of the solder pastes 2 and 54 located at the four corners of the soldering portions 32a and 34a, and the soldering strength can be improved.

(2) During heating or melting of the cream solder 16 or 18 for some reason, as shown in FIG. 5 (a), a positional deviation occurs in the left-right direction between the ground terminal 20a and the pads 12 and 14, resulting in a through hole. When the right side portion of the inner wall surface of 36a is displaced from the outer wall surface of the pad 12 to the outside, the force due to the surface tension of the molten cream solder 16a causes the ground terminal 2
The bottom plate 22a of 0a receives the leftward force indicated by the arrow in the figure and moves to the position shown in FIG. This is because when the right side portion of the inner wall surface of the through hole 36a shifts to the right side from the outer wall surface of the pad 12, the molten cream solder 16a wraps around the inner wall surface of the periphery of the shifted inner wall surface portion. Conceivable. In addition, as shown in FIG. 5B, the ground terminal 20a and the pad 12,
When there is no misalignment between 14
Since 6a and 18a are uniformly attached to almost all the inner wall surfaces of the through holes 36a and 38a, the shape of the solder fillet formed over the inner wall surfaces of the through holes 36a and 38a and the pads 12 and 14 is the same. And the soldering strength increases.

(3) Further, as shown in FIG. 5A, when the ground terminal 20a and the pads 12, 14 are displaced in the left-right direction, the notches 40, 48 and the notches 42, 50 are formed.
The amount of the molten cream solder 16a adhering to the unbalance becomes unbalanced, and the notches 44, 52 and the notches 46, 54
The amount of the molten cream solder 18a adhering to the pad becomes unbalanced, and the displacement of the soldering portions 32a, 34a with respect to the pads 12, 14 is suppressed by the force resulting from the surface tension of the molten cream solder 16a, 18a. Further, since the solder fillet is formed across the cutouts 40 to 54 of the ground terminal 20a and the pads 12 and 14, the cutouts 40 to 54 are formed.
As compared with the case without 54, the shape of the solder fillet becomes larger and the soldering strength increases.

FIG. 6 shows an example in which the maximum inner wall surface interval between the two through holes is made equal to the maximum outer wall surface interval between the pair of pads. In FIG. 6, the same parts as those in FIG. 1 will be described. Is omitted. In FIG. 6, 20b is a ground terminal,
22b is a bottom plate, 32b and 34b are soldered portions, 36b,
Reference numeral 38b is a through hole having a diameter r2 (r2 <Lx), and the centers of the through holes 36b and 38b are the soldering portions 32b and 34.
It does not coincide with the centers O1 and O2 of b. The through hole 36b,
The maximum inner wall surface distance K2 between 38b is equal to that of a pair of pads 1
Although it is formed to be equal to the maximum outer wall surface interval P2 between the two pads 14, 14, the minimum inner wall surface interval K1b is set to a pair of pads 12,14.
It is not equal to the minimum outer wall surface interval P1 between them.

Next, the schematic operation of FIG. 6 will be described with reference to FIG. (1) If there is no misalignment between the soldering portions 32b, 34b of the ground terminal 20b and the pads 12, 14, the molten cream solder 16a, 18a will be in the through holes 36b, 38b as shown in FIG. 7B. It is formed by uniformly and uniformly adhering to the wall surface, and after cooling, a solder fillet having substantially the same shape is formed on the inner wall surfaces of the through holes 36b and 38b, and a large soldering strength is obtained. Further, the notches 40, 42, 48, 50 and the notches 44, 46, 5 of the ground terminal 20b.
Solder fillets (not shown) of the molten cream solders 16a and 18a are also formed on the portions of the solder pastes 2 and 54 located at the four corners of the soldering portions 32b and 34b, and the soldering strength can be improved.

(2) During heating or melting of the cream solders 16 and 18 due to some cause, as shown in FIG. 7 (a), a positional deviation occurs in the left-right direction between the ground terminal 20b and the pads 12 and 14, and the through holes are formed. When the left side portion of the inner wall surface of 36b deviates from the outer wall surface of the pad 12 to the outside, the force due to the surface tension of the molten cream solder 16a causes the ground terminal 2
0b receives the rightward force indicated by the arrow in the figure and moves to the position shown in FIG. This is considered to be because when the left side portion of the inner wall surface of the through hole 36b shifts to the left side from the outer wall surface of the pad 12, the molten cream solder 16a wraps around the shifted inner wall surface portion along the circumferential inner wall surface. . Further, as shown in FIG. 7B, when the positional displacement between the ground terminal 20b and the pads 12 and 14 is eliminated, the molten cream solders 16a and 18a are evenly distributed on almost all the inner wall surfaces of the through holes 36b and 38b. Adhere to the inner wall surfaces of the through holes 36b and 38b and the pad 12,
The shape of the solder fillet formed over 14 is enlarged as a whole to increase the soldering strength.

(3) Further, as shown in FIG. 7A, when the ground terminal 20b and the pads 12, 14 are displaced in the left-right direction, the notches 40, 48 of the ground terminal 20b are formed.
And molten cream solder 16a attached to the notches 42 and 50
Is unbalanced and notches 44, 52
And molten cream solder 18a attached to the notches 46 and 54
Becomes unbalanced, and the soldering portions 32b, 34 are caused by the force resulting from the surface tension of the molten cream solder 16a.
The displacement of b with respect to the pads 12 and 14 is suppressed.

In the above-mentioned embodiment, the case where the notch is formed in the bottom plate of the terminal and a part of the notch is formed so as to be located in the soldering portion has been described, but the present invention is not limited to this. It can also be used when the notch is omitted.

In the embodiment described above, the length W in the direction parallel to the perpendicular bisector Z connecting the centers O1 and O2 of the two soldered portions of the terminal (V-axis direction) is defined by the pad arrangement. Although the case where it is formed to be smaller than the length Ly in the Y-axis direction perpendicular to the direction has been described, the present invention is not limited to this, and it is also applicable to the case where the length W is formed to be larger than the length Ly. You can

In the above-described embodiment, a pair of pads formed on the printed wiring board are arranged in the X direction parallel to the array direction.
It is formed by two right-angled quadrangular pads having a length Lx in the axial direction and a length Ly in the Y-axis direction perpendicular to the arrangement direction, and the through holes formed in the two soldering portions of the terminals are circular. Although the case where the pad is formed in a shape has been described, the present invention is not limited to this, and the pair of pads formed on the printed wiring board has a shape other than the square shape (for example, square shape or circular shape). The two through holes are formed in the two soldering parts of the terminal, and the through holes formed in the two soldering portions of the terminal are other than circular shapes (elliptical shape, triangular shape, polygonal shape such as square shape). It can also be used when it is done.

In the above embodiment, the case where the number of through holes formed in each soldering portion is one for the corresponding pad has been described, but the present invention is not limited to this, and each soldering portion is not limited to this. It can also be used in the case where the number of through holes formed in the attachment portion is plural with respect to the corresponding pad. For example, in the soldering portions 32a and 34a in which the through holes 36a and 38a of FIG. 4 are formed, the through holes 36 of FIG.
It is also possible to use a case where through holes having the same structure as b and 38b are formed and the number of through holes formed in each soldering portion is two for the corresponding pad.

In the above embodiment, the case where the number of pads formed on the printed wiring board is two and the number of through holes corresponding to the number of through holes formed in the soldering portions of the terminals is two has been described. Is not limited to this, but it is also applicable to the case where there is one pad formed on the printed wiring board and correspondingly one or more through holes formed in the soldering portions of the terminals. You can

For example, as shown in FIG. 8, for one pad 12A formed on the printed wiring board 10A, the soldering portion 32A of the bottom plate 22A of the ground terminal 20A is attached.
Has one through hole 36A, the bottom plate 22A of the soldering portion 32A has a plate width W1 larger than the corresponding side length Ly1 of the pad 12A, and the soldering portion 32A has a pad 12A.
The same can be applied to the case where the through hole 36A having a similar shape, which is slightly smaller than the pad 12A, is formed in the portion corresponding to.

In the embodiment shown in FIG. 8, the terminals 20A and the pads 12A are melted during the melting of the cream solder for some reason.
When the right side portion of the inner wall surface of the through hole 36A is displaced outward from the outer wall surface of the pad 12A as shown in FIG. 8A, a force due to the surface tension of the molten cream solder is generated. As a result, the ground terminal 20A receives the leftward force indicated by the arrow in the figure and moves to the position shown in FIG. This is because when the left side portion of the inner wall surface of the through hole 36A shifts to the left side from the outer wall surface of the pad 12, the melted cream solder 1 is removed from the shifted inner wall surface portion.
It is considered that this is due to the fact that 6a goes around along the inner wall surface. Further, the ground terminal 20A receives a vertical force indicated by an arrow in the figure due to a force caused by the surface tension of the molten cream solder, but when the vertical position is not displaced, these forces are balanced so that they move in the vertical direction. do not do.
Furthermore, since the solder fillet of the molten cream solder is formed on most of the inner wall surface of the through hole 36A by suppressing the positional deviation, the soldering strength can be improved.

In the above-described embodiment, the case where the terminal is the ground terminal has been described, but the present invention is not limited to this, and terminals other than the ground terminal may be formed on the printed wiring board. Alternatively, it can be used for a terminal in which a bottom plate placed on a pair of pads via cream solder is provided, and a soldering portion is formed at a portion of the bottom plate corresponding to the pad. That is, the cream solder can be used for all terminals soldered to the printed wiring board by heating and melting the cream solder in the reflow bath.

[0038]

According to the invention of claim 1, a through hole having a symmetrical shape with respect to a perpendicular bisector Z of a line segment connecting the centers O1 and O2 of the two soldering portions is formed in the two soldering portions. Two
Since the minimum inner wall surface interval K1 between the two through holes is formed to be substantially equal to the minimum outer wall surface interval P1 between the pair of pads, the terminal and the pad are displaced during melting of the cream solder for some reason, and the minimum inner wall surface interval K1 is generated. When a part of the inner wall surface of one of the two through holes with the wall surface spacing of K1 shifts outward from the outer wall surface of the pad, the force due to the surface tension of the molten cream solder acts in the direction of eliminating the positional shift with respect to the bottom plate. It is possible to suppress the positional deviation between the terminal and the pad. Further, since the solder fillet of the molten cream solder is formed on most of the inner wall surface of the through hole by suppressing the positional deviation between the terminal and the pad, it is possible to increase the shape of the solder fillet and improve the soldering strength.

According to the second aspect of the invention, the two soldering portions are
Vertical 2 of the line segment connecting the centers O1 and O2 of the two soldered parts
Since a through hole having a symmetrical shape with respect to the bisector Z was formed and the maximum inner wall surface interval K2 between the two through holes was formed to be substantially equal to the maximum outer wall surface interval P2 between the pair of pads, the cream was for some reason caused. When the terminals and the pads are displaced during the melting of the solder and a part of the inner wall surface of one of the two through holes with the maximum inner wall surface spacing of K2 is displaced outward from the outer wall surface of the pad, it is caused by the surface tension of the molten cream solder. The acting force acts on the bottom plate in a direction to eliminate the positional displacement, and the positional displacement between the terminal and the pad can be suppressed. Further, since the solder fillet of the molten cream solder is formed on most of the inner wall surface of the through hole by suppressing the positional deviation between the terminal and the pad, the shape of the solder fillet can be increased to improve the soldering strength.

According to a third aspect of the present invention, in the first or second aspect of the present invention, a pair of pads has a length Lx in the X-axis direction parallel to the arrangement direction, and a length in the Y-axis direction perpendicular to the arrangement direction. Two right-angled quadrangular pads having a length of Ly, and the length W in the direction perpendicular to the straight line passing through the centers O1 and O2 of the soldering portion is L
It is formed to be shorter than y, and a notch is formed on the opposite outer sides along the direction parallel to the straight line passing through the centers O1 and O2 of the soldering portion, and the shape of this notch is formed with respect to the straight line passing through the centers O1 and O2. Since it is formed in a symmetrical shape, it is possible to further improve the positional deviation suppressing effect and the soldering strength.

According to a fourth aspect of the present invention, in the first, second or third aspect of the present invention, the pair of pads has a length Lx in the X-axis direction parallel to the arrangement direction and a Y-axis perpendicular to the arrangement direction. Two right-angled quadrangular pads whose length in the direction is Ly are two circular penetrating holes 2 having a diameter R substantially equal to Lx.
Since the number of individual pieces is set, the soldering portion having a simple structure can improve the positional deviation suppressing effect and the soldering strength.

According to a fifth aspect of the present invention, in the first, second or third aspect of the present invention, the pair of pads has a length Lx in the X-axis direction parallel to the arrangement direction and a Y-axis perpendicular to the arrangement direction. Two right-angled quadrangular pads whose length in the direction is Ly are provided, and the two through-holes are square-shaped through-holes 2 with one side being substantially equal to Lx.
Since the number of individual pieces is set, the soldering portion having a simple structure can improve the positional deviation suppressing effect and the soldering strength.

[0043]

[Brief description of drawings]

FIG. 1 shows a first embodiment of a terminal according to the present invention, (a) is a plan view, (b) is a front view, and (c) is a bottom view.

2 shows a terminal 20 in FIG. 1, (a) of FIG.
1B is a left side view of the terminal 20 in FIG. 1B, and FIG. 1B is a right side view of the terminal 20 in FIG.

FIG. 3 is a view for explaining the operation of the terminals of FIGS. 1 and 2.
1A is an enlarged cross-sectional view of a main portion showing a state where the soldering portions 32 and 34 of the terminal 20 and the pads 12 and 14 on the printed wiring board 10 in FIG. 1 are displaced, and FIG. It is a principal part expanded sectional view which shows the state which the position gap was corrected.

FIG. 4 is a bottom view showing a second exemplary embodiment of the terminal according to the present invention.

5 is a view for explaining the operation of the terminal 20a of FIG.
(A) is a soldering part 32a, 34 of the terminal 20a in FIG.
3A is an enlarged cross-sectional view of an essential part showing a state where the pads 12 and 14 on the printed wiring board 10 are displaced from each other, and FIG. .

FIG. 6 is a bottom view showing a third exemplary embodiment of the terminal according to the present invention.

7 is a view for explaining the action of the terminal 20b of FIG.
(A) is a soldering part 32b, 34 of the terminal 20b in FIG.
b is an enlarged sectional view of an essential part showing a state where the pads 12 and 14 on the printed wiring board 10 are displaced, and FIG. 7B is an enlarged sectional view of an essential part showing a state where the displacement is corrected by the displacement suppressing effect. .

FIG. 8 shows a fourth embodiment of the terminal according to the present invention, in which (a) is an enlarged cross-sectional view of an essential part showing a state where the soldering part 32A of the terminal 20A and the pad 12A on the printed wiring board 10A are misaligned. FIG. 1B is an enlarged cross-sectional view of an essential part showing a state where the positional displacement is corrected by the positional displacement suppressing effect.

[Explanation of symbols]

10, 10A ... Printed wiring board, 12, 14 ... Grounding pad (one example of pad), 16, 18 ... Cream solder, 16a, 18a ... Molten cream solder, 20, 2
0a, 20b, 20A ... Ground terminal (an example of terminal),
22, 22a, 22b, 22A ... Bottom plate, 24 ... Folding portion, 26 ... Contact portion, 32, 32a, 32b, 32
A, 34, 34a, 34b ... Soldering part, 36, 36
a, 36b, 36A, 38, 38a, 38b ... through-hole,
40 to 54 ... Notches, K1 ... Minimum inner wall surface spacing, K
2 ... Maximum inner wall surface spacing, Lx ... Length in the X-axis direction parallel to the arrangement direction of the pads 12, 14, Ly ... Pads 12, 1
4, the length in the Y-axis direction perpendicular to the arrangement direction, O1, O2 ...
Center of soldering part, P1 ... Minimum outer wall surface interval, P2 ...
Maximum outer wall surface spacing, U ... Axial direction of straight line passing through centers O1 and O2 of soldering portion, V ... Centers O1 and O2 of soldering portion
The axial direction of the perpendicular bisector of the line segment connecting W, the plate width of the bottom plate (the length of the bottom plate in the V-axis direction), the axial direction parallel to the arrangement direction of the X pair of pads, the Y pair , An axial direction perpendicular to the pad array direction, Z ... A perpendicular bisector of a line segment connecting the centers O1 and O2 of the soldering portion.

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP-A-9-115574 (JP, A) JP-A-11-317250 (JP, A) JP-A-5-101965 (JP, A) JP-A-2000-77834 (JP, A) JP 2000-195597 (JP, A) Actually opened 5-90932 (JP, U) Actually opened 58-178282 (JP, U) Actually opened 62-190372 (JP, U) (58 ) Fields surveyed (Int.Cl. ⁷ , DB name) H01R 9/09 H01R 23/68 H01R 4/02 H01R 4/64

Claims (5)

(57) [Claims] 1. A bottom plate placed on a pair of pads formed on a printed wiring board via cream solder, the bottom plate being soldered to a portion corresponding to each of the pair of pads. In the terminal having the soldering portion formed, the centers O1 and O2 of the two soldering portions are connected to the two soldering portions.
A through hole having a symmetrical shape with respect to a perpendicular bisector Z connecting the line segments, and the minimum inner wall surface interval K between the two through holes is formed.
1 is formed to be substantially equal to the minimum outer wall surface interval P1 between the pair of pads. 2. A bottom plate mounted via cream solder on a pair of pads formed on a printed wiring board. Solder is provided on a portion of the bottom plate corresponding to each of the pair of pads. In the terminal having the soldering portion formed, the centers O1 and O2 of the two soldering portions are connected to the two soldering portions.
A through hole having a symmetrical shape with respect to a perpendicular bisector Z connecting the line segments, and the maximum inner wall surface distance K between the two through holes is formed.
2 is formed to be approximately equal to the maximum outer wall surface interval P2 between the pair of pads. 3. A pair of pads are X-parallel to the array direction.
A straight line passing through the centers O1 and O2 of the soldering part, which is composed of two right-angled quadrangular pads having an axial length of Lx and a Y-axis length of Ly (Lx ≦ Ly) perpendicular to the array direction. A length W in the direction perpendicular to the above is shorter than the Ly, and notches are formed in the outer sides facing each other along a direction parallel to a straight line passing through the centers O1 and O2 of the soldering portions. 3. The terminal according to claim 1, wherein the terminal is formed in a symmetrical shape with respect to a straight line passing through the centers O1 and O2. 4. A pair of pads are X-parallel to the array direction.
The two through-holes have a diameter R of Lx and Lx is two right-angled quadrangular pads having a length Lx in the axial direction and a length Ly (Lx ≦ Ly) in the Y-axis direction perpendicular to the arrangement direction. The terminal according to claim 1, 2 or 3, comprising two circular through holes substantially equal to the above. 5. A pair of pads are arranged in an X direction parallel to the arrangement direction.
It is composed of two right-angled quadrangular pads each having a length Lx in the axial direction and a length Ly (Lx ≦ Ly) in the Y-axis direction perpendicular to the arrangement direction, and two through-holes each have one side of the Lx. The terminal according to claim 1, 2 or 3, comprising two through-holes each having a square shape substantially equal to the above.