Terminal, connector, and board assembly

Abstract

To provide a front surface mounting structure in which a terminal is hardly separated from a substrate.SOLUTION: A connector mounted to a substrate such as an FPC or the like in a front surface, comprises: a plurality of terminals 3; and a resin housing that holds the terminals 3. Each terminal 3 is formed so that one metal plate is folded, and includes a first connection part 31 bonded to a mating terminal at one end side, and includes a second connection part 32 soldered so as to overlap the substrate at the other end side. In the second connection part 32, a rectangular-shaped metal plate is folded in two, forming a U-shape. In the second connection part 32, a two-folded folding 32a is arranged onto the substrate, and two plate-like parts 32b on both sides of the folding 32a are arranged vertically with respect to the substrate, and are soldered.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to terminals that are stacked and soldered to a substrate. [Background technology]

[0002] Connectors for connecting circuits are available in various structures, and Patent Document 1 discloses a connector that is surface-mounted on a board. This connector includes a housing and a plurality of terminals held by the housing. One end of each terminal is positioned inside the housing, the other end is positioned outside the housing and soldered to the board, and the center is press-fitted into a terminal press-fit hole in the housing. The other end is formed in a flat plate parallel to the board, and is soldered over the board.

[0003] The connector is mounted on a board on which solder paste has been applied in advance, and the board is heated in a reflow furnace to solder the terminals to the board. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2021-182487 A Summary of the Invention [Problem to be solved by the invention]

[0005] In the above-mentioned conventional technology, the terminals are soldered to the surface of the board, and therefore there is a problem that the terminals are more likely to separate from the board than when the terminals are inserted into through-holes in the board and soldered.

[0006] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a surface mounting structure in which terminals are less likely to separate from a substrate. [Means for solving the problem]

[0007] The terminal of the present invention is characterized in that it is formed by bending a metal plate, has a first connection portion at one end that is adapted to mate with a mating terminal, and has a second connection portion at the other end that is overlaid on a substrate and soldered thereto, the second connection portion being formed by folding a rectangular metal plate in half.

[0008] The connector of the present invention comprises the terminal and a housing, the first connection portion being positioned inside the housing and the second connection portion being positioned outside the housing.

[0009] The board assembly of the present invention comprises the connector and a board on which the connector is surface-mounted, and is characterized in that the second connection portion has a two-fold crease positioned on the board, two plate-shaped portions on either side of the crease are perpendicular to the board, and solder is interposed between the outer surface of the second connection portion and the board. Effect of the Invention

[0010] According to the present invention, it is possible to realize a surface mounting structure in which the terminals are unlikely to separate from the substrate. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a perspective view showing a board assembly according to an embodiment of the present invention. [Diagram 2] FIG. 2 is an exploded view of the board assembly of FIG. 1 (the cover is not shown). [Diagram 3] FIG. 3 is an enlarged view of the terminal of FIG. 2. [Figure 4] FIG. 2 is a rear view of the connector in FIG. 1 (the cover is not shown). [Diagram 5] 5 is a diagram for explaining the shape of a cavity in the housing of FIG. 4. FIG. [Figure 6] FIG. 3 is a diagram for explaining the surface mounting structure of the terminal and the substrate in FIG. 2. [Figure 7] FIG. 7 is a diagram showing a state in which the terminals in FIG. 6 are soldered to a board. [Figure 8] FIG. 8 is a cross-sectional view taken along the line AA in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A "terminal," "connector," and "substrate assembly" according to one embodiment of the present invention will be described with reference to FIGS.

[0013] 1 includes a connector 2 and an FPC (short for Flexible Printed Circuits, equivalent to a "substrate") 10 on which the connector 2 is surface-mounted. This connector 2 fits with a mating connector (not shown).

[0014] 2, the FPC 10 has a wiring pattern (not shown) and pads 12, 13 formed on the surface of a base film 11. The pad 12 is a portion to which a peg 20 (described later) is soldered. The pad 13 is a portion to which a second connection portion 32 of a terminal 3 (described later) is soldered. Solder paste is applied onto the pads 12, 13 in advance, and the peg 20 and terminal 3 are mounted thereon, and then soldered in a reflow furnace.

[0015] As shown in FIG. 2, the connector 2 includes a housing 4, a plurality of terminals 3 held in the housing 4, a pair of pegs 20 that secure the housing 4 and the FPC 10 by soldering, and a cover 5 (shown in FIG. 1) attached to the housing 4.

[0016] The housing 4 is made of insulating synthetic resin. The housing 4 integrally comprises a rectangular parallelepiped main body 40, peg attachment parts 42 connected to both side surfaces of the main body 40, and a lock arm 43 connected to the top surface of the main body 40. The lock arm 43 is a part that maintains the mated state of the connector 2 and the mating connector by engaging with the mating connector.

[0017] The main body 40 is formed with cavities 41 each accommodating the terminals 3 in the same number as the terminals 3. The cavities 41 extend in the front-rear direction (arrow Z direction) of the main body 40 and open to the front (front surface) and rear (rear surface) of the main body 40. The terminals 3 are inserted into the cavities 41 from the opening on the rear surface of the main body 40. Mating terminals of a mating connector are inserted into the cavities 41 from the opening on the front surface of the main body 40 and fitted with the terminals 3. The cavities 41 are lined up in the width direction of the main body 40 (arrow X direction) and lined up in two rows, vertically (arrow Y direction).

[0018] In this specification, the mating connector side of the connector 2 in the mating direction (arrow Z direction) is defined as the "front", and the side away from the mating connector in the mating direction (FPC 10 side) is defined as the "rear". For convenience of explanation, "upper", "lower", "left", and "right" are expressed based on the orientation of the paper surface of the drawings. These front, rear, upper, lower, left, and right directions do not have to match the actual directions in the usage situation of the connector 2.

[0019] The peg 20 is a metal part that is attached to a peg attachment portion 42 of the housing 4 and soldered to a pad 12 of the FPC 10. The peg 20 is a part for fixing the housing 4 and the FPC 10, and is not a part that constitutes a circuit.

[0020] The cover 5 is made of insulating synthetic resin. The cover 5 is attached to the rear side of the housing 4, and protects the FPC 10 by positioning the FPC 10 between the cover 5 and the housing 4. The cover 5 is provided with an operating portion 53, and pressing the operating portion 53 can bend the lock arm 43 in a direction to detach it from the mating connector.

[0021] The terminal 3 is formed by punching a metal plate into a predetermined shape and bending the metal plate of the predetermined shape. As shown in Fig. 3, the terminal 3 has a first connection portion 31, a second connection portion 32, a belt-shaped linking portion 33 that links the first connection portion 31 and the second connection portion 32, and a pair of first press-fit portions 34 and a pair of second press-fit portions 35 that are press-fitted into the housing 4.

[0022] The first connection part 31 is formed in a rectangular tube shape capable of receiving a rod-shaped mating terminal provided in a mating connector. The first connection part 31 has a spring piece inside the rectangular tube shape that elastically contacts the mating terminal. That is, the mating terminal is a male terminal, and the terminal 3 is a female terminal, and the two are fitted together.

[0023] The terminal 3 in this example is a female terminal having a first connection portion 31 as described above, and is formed using a thin plate that is about one-third the thickness of the metal plate used to form the male terminal in order to ensure good spring properties of the spring piece.

[0024] The second connection portion 32 is formed by folding a rectangular metal plate in half. The second connection portion 32 is placed on the FPC 10 and soldered to the pad 13.

[0025] The connecting portion 33 is continuous with one wall of the rectangular cylindrical body of the first connecting portion 31. The width of the connecting portion 33 is formed slightly smaller than the width of the first connecting portion 31.

[0026] The pair of first press-fit portions 34 protrude in directions away from each other from both widthwise ends of the connecting portion 33 and are formed flush with the connecting portion 33 .

[0027] The pair of second press-fit portions 35 are bent at right angles and opposed to each other at both widthwise ends of the connecting portion 33. The pair of second press-fit portions 35 are disposed closer to the second connecting portion 32 than the pair of first press-fit portions 34.

[0028] A step 36 is formed on the first connecting portion 31 side of the pair of first press-fit portions 34 of the connecting portion 33. The step 36 is formed by bending the connecting portion 33 into a crank shape. Due to the formation of this step 36, the pair of first press-fit portions 34 and the pair of second press-fit portions 35 are vertically misaligned with the first connecting portion 31 in a state in which the terminal 3 is held in the housing 4. In addition, a bent portion 37 bent at a right angle is formed on the second connecting portion 32 side of the pair of second press-fit portions 35 of the connecting portion 33. With the terminal 3 held in the housing 4, a portion of the connecting portion 33 between the step 36 and the bent portion 37 extends in the front-rear direction of the main body portion 40 (the direction of the arrow Z).

[0029] 4 and 5, the terminal 3 is positioned such that the first connection portion 31 side of the bent portion 37 is located inside the cavity 41, and the second connection portion 32 side of the bent portion 37 is located outside the cavity 41. The terminal 3 is inserted into the cavity 41 from the opening on the back surface of the main body 40, and is inserted into the cavity 41 from the first connection portion 31 side to the second connection portion 32 side, with the first connection portion 31 side at the front.

[0030] As shown in FIG. 5, the cavity 41 includes a portion 41a through which the first connection portion 31 passes and is accommodated, a portion 41b through which the connecting portion 33 passes and is accommodated, a portion 41c through which the pair of first press-fit portions 34 pass and are respectively accommodated, and a portion 41d through which the pair of second press-fit portions 35 are respectively accommodated.

[0031] The pair of first press-fit portions 34 are press-fitted into the portion 41c of the cavity 41 with an overlap in a first direction (the direction of the arrow X, which is the width direction of the housing 4) that is the width direction of the connecting portion 33. The pair of second press-fit portions 35 are press-fitted into the portion 41d of the cavity 41 with an overlap in a second direction (the direction of the arrow Y, which is the height direction of the housing 4) that is perpendicular to the first direction.

[0032] In this manner, the terminal 3 has a pair of first press-fit portions 34 that have an overlap in the first direction and are press-fitted into the cavity 41, and a pair of second press-fit portions 35 that have an overlap in the second direction and are press-fitted into the cavity 41. This can increase the holding force and positional accuracy of each terminal 3 in the connector 2. This can stabilize the coplanarity of the multiple terminals 3.

[0033] In addition, the pair of first press-fitting portions 34 and the pair of second press-fitting portions 35 of the terminal 3 are misaligned in the vertical direction with the first connecting portion 31. This configuration can prevent the terminal 3 from becoming large. That is, if the pair of first press-fitting portions 34 are arranged at the same height as the first connecting portion 31, the pair of first press-fitting portions 34 cannot be press-fitted into the housing 4 unless the length between the tips of the pair of first press-fitting portions 34 is formed to be larger than the width of the first connecting portion 31, and the terminal 3 becomes large in the width direction. Similarly, if the pair of second press-fitting portions 35 are arranged at the same height as the first connecting portion 31, the pair of second press-fitting portions 35 cannot be press-fitted into the housing 4 unless the height of each second press-fitting portion 35 is formed to be larger than the height of the first connecting portion 31, and the terminal 3 becomes large in the height direction. In this example, such an increase in size of the terminal 3 can be prevented.

[0034] Next, a more detailed description will be given of the surface mounting structure of the terminal 3 and the FPC 10. As shown in Figs. 6 to 8, the second connection portion 32 is soldered to the pad 13 with the fold 32a of the double fold disposed on the pad 13 of the FPC 10 and the two plate-like portions 32b on both sides of the fold 32a disposed perpendicular to the FPC 10.

[0035] As described above, the FPC 10 has solder paste applied to the pads 13 in advance. The solder paste contains solder powder and a paste-like flux. The second connection portion 32 is mounted on the portion to which the solder paste is applied, as shown in FIG. 6, and the second connection portion 32 is soldered to the pads 13 by heating the FPC 10 together with the second connection portion 32 in a reflow furnace. After the reflow process, as shown in FIG. 7, solder 6 is present between the outer surface of the second connection portion 32 and the FPC 10, and a good solder fillet is formed.

[0036] In the surface mount structure of this example, the second connection portion 32 is folded in half to form a U-shape, so that the contact area with the solder 6 can be increased compared to the conventional surface mount structure in which the second connection portion 32 is formed in a flat plate shape. That is, the contact area with the solder 6 at each terminal 3 can be increased without increasing the terminal pitch. Also, as shown in FIG. 8, since there is a wide gap between the outer surface of the second connection portion 32 and the FPC 10, the flux F in the solder paste activated during reflow sufficiently wets and spreads over the outer surface of the second connection portion 32. Furthermore, as shown by the arrow in FIG. 8, this flux F can easily escape from between the outer surface of the second connection portion 32 and the FPC 10, so that voids can be suppressed. As a result, a surface mount structure in which the terminal 3 is unlikely to separate from the FPC 10 and has high connection reliability can be realized.

[0037] In the above-described embodiment, the connector 2 is surface-mounted on the FPC 10 which is a flexible substrate, but the connector of the present invention may also be surface-mounted on a rigid substrate.

[0038] In the above-described embodiment, the first connection portion 31 is formed in a rectangular tube shape, but in the present invention, the first connection portion may be formed in a rod shape.

[0039] The above-described embodiment merely shows a typical form of the present invention, and the present invention is not limited to this embodiment. In other words, the present invention can be embodied in various modifications without departing from the gist of the present invention. As long as the configuration of the present invention is still provided even with such modifications, it is of course included in the scope of the present invention. [Explanation of symbols]

[0040] 1 Board Assembly 2 Connector 3 Terminal 4. Housing 10 FPC (substrate) 31 First connection part 32 Second connection part

Claims

1. It is made by bending a single metal plate, a first connection portion at one end adapted to be fitted with a mating terminal, and a second connection portion at the other end adapted to be placed on and soldered to a substrate; The second connection portion is formed by folding a rectangular metal plate in half. A terminal characterized by:

2. The first connection portion is formed in a cylindrical shape capable of receiving a mating terminal.

2. The terminal according to claim 1 .

3. A terminal according to claim 1 or 2 and a housing, The first connection portion is located inside the housing and the second connection portion is located outside the housing. A connector characterized by:

4. A connector according to claim 3 and a substrate on which the connector is surface-mounted, The second connection portion has a fold line disposed on the substrate, and two plate-shaped portions on both sides of the fold line are perpendicular to the substrate; Solder is interposed between an outer surface of the second connection portion and the substrate. A substrate assembly comprising:

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