JP2019016554A - Terminal fitting - Google Patents

Abstract

To provide a terminal fitting capable of restraining reduction in connection reliability of the terminal fitting and a circuit board.SOLUTION: A terminal fitting 3 has a connection 32 electrically connected conductively with a current-carrying part 5b via a solder 6, a dowel 33 provided farther to the rear end 36 side than the connection 32 in the extension direction, and multiple plating layers including an inside layer 3b mainly composed of a first metal having wettability lower than that of the main component metal of the solder 6, and an outside layer 3c mainly composed of a second metal having wettability higher than that of the first metal. The dowel 33 has a pair of deformation parts 33b projecting in the width direction, and an internal exposure surface 33c having one end, out of both ends in the opposite direction, coupled with the surface part 33a, and the other end coupled with the deformation parts 33b. The pair of deformation parts 33b are formed so that the total length of the pair of deformation parts 33b in the width direction becomes larger than the diameter of a through hole 5a, and a pair of internal exposure surfaces 33c are exposing the first metal.SELECTED DRAWING: Figure 8

Description

  The present invention relates to a terminal fitting.

  2. Description of the Related Art Conventionally, terminal fittings that are solder-connected to a printed circuit board include a terminal body that is inserted into a through hole formed in the circuit board (see Patent Document 1). On the surface of the circuit board, solder containing tin as a main component is printed so as to cover the opening of the through hole, and the terminal body is inserted into the through hole while penetrating the solder. Thereafter, the circuit board is passed through a reflow furnace, and the solder is melted and solidified, whereby a solder fillet is formed between the terminal body and the circuit board, and is electrically connected to the terminal body.

JP 2011-151247 A

  By the way, before the terminal fitting is mounted on the circuit board, a plating layer made of a metal having lower wettability than tin is formed on the tip of the terminal fitting, so that the solder melted by the reflow process is behind the tip of the terminal fitting. Sucked to the end side. That is, it is possible to suppress the movement of solder by forming a plating layer made of a metal having lower wettability than tin on the terminal fitting. On the other hand, when mounting a multi-pole connector on a circuit board, a plurality of terminal fittings of the multi-pole connector will be electrically connected to the circuit board at the same time. As a result, the solder sucks up. Therefore, there is a possibility that the conductive connection between the terminal fitting and the conductive portion formed on the opening edge portion of the inner peripheral surface of the through hole and the front and back surfaces of the through hole may be lowered, which may cause a decrease in connection reliability. there were.

  This invention is made in view of the above, Comprising: It aims at providing the terminal metal fitting which can suppress the fall of the connection reliability of a terminal metal fitting and a circuit board.

  In order to solve the above-described problems and achieve the object, the present invention provides a terminal fitting whose tip extends in the extending direction toward the circuit board, provided on the tip side, and through the circuit board. A connecting portion electrically connected to the conductive portion formed on the inner peripheral surface and the opening edge of the hole so as to be conductive through solder, and a rear end opposite to the leading end side in the extending direction from the connecting portion A dowel provided on the side, an inner layer mainly composed of a first metal having lower wettability than the metal that is the main component of the solder, and a second metal having higher wettability than the first metal. A plating layer including an outermost layer as a component, and the dowel has a surface portion facing in a facing direction orthogonal to the extending direction, and the surface portion in the extending direction and a width direction orthogonal to the facing direction. A pair of deformed portions projecting in the width direction One end of the opposite ends in the opposite direction is connected to the surface portion, and the other end is connected to the deformed portion, and the pair of deformed portions includes the pair of deformed portions in the width direction. The combined length is formed larger than the diameter of the through hole, and at least the first metal is exposed on the pair of internal exposed surfaces.

  The terminal fitting according to the present invention has an effect that it is possible to suppress a decrease in connection reliability between the terminal fitting and the circuit board.

FIG. 1 is a perspective view illustrating a connector according to an embodiment. FIG. 2 is a perspective view when the connector shown in FIG. 1 is viewed from another direction. FIG. 3 is an exploded perspective view showing the connector of the embodiment. FIG. 4 is a perspective view showing the terminal fitting of the embodiment. FIG. 5 is an enlarged view of FIG. 4 and a perspective view showing a dowel. FIG. 6 is an enlarged schematic view seen from the back before the terminal fitting is mounted on the circuit board. FIG. 7 is an enlarged schematic view after the terminal fitting in FIG. 6 is mounted on the circuit board. FIG. 8 is an enlarged schematic view seen from a cross section taken along line XX of FIG.

  Hereinafter, embodiments of a terminal fitting according to the present invention will be described in detail with reference to the drawings. In addition, this invention is not limited by this embodiment.

Embodiment
1 to 8 is an extending direction in which the terminal fitting 3 extends toward the circuit board 5 in the present embodiment, and is the vertical direction of the connector 1. The Y direction is a width direction orthogonal to the extending direction, and is an arrangement direction of the connectors 1 in the present embodiment. The Z direction is a facing direction orthogonal to the extending direction and the width direction, and is the front-rear direction of the connector 1 in the present embodiment. The X1 direction is a direction in which the tip 35 of the terminal fitting 3 is directed toward the circuit board 5 (hereinafter referred to as the extending tip 35 side), and the X2 direction is a direction from the tip 35 of the terminal fitting 3 toward the rear end 36. This is a direction away from the circuit board 5 when the metal fitting 3 is straight.

  As shown in FIG. 1, the connector 1 according to the present embodiment is configured by housing a terminal fitting 3 inside a housing, and conductively connects the terminal fitting 3 to a mating terminal. It constitutes a connection mechanism for wire connection and a connection mechanism for wire-to-board. In the present embodiment, as an example of this connector, a connector 1 which is one of wire-to-board connection mechanisms will be described. As shown in FIG. 2, the connector 1 electrically connects a plurality of terminal fittings 3 supported by a housing 2 (housing) to a circuit board (PCB) 5 via solder 6 so as to be conductive. Configured. The connector 1 is engaged with a mating mating connector (not shown) to electrically connect the internal terminal fitting 3 to a terminal fitting (not shown) accommodated in the mating connector in a conductive manner. . With this conductive connection, the circuit board 5 connected to the terminal fitting 3 can be electrically connected to an electric wire or the like connected to the terminal fitting of the mating connector. The connector 1 includes a housing 2, a terminal fitting 3, and an aligning plate 4.

  As shown in FIG. 3, the housing 2 has a substantially rectangular parallelepiped block shape made of an insulating synthetic resin, and includes a fitting port 21, an accommodation space 22, and a terminal holding wall 23. The fitting port 21 is formed on a surface that is a fitting side with the mating connector, and the accommodation space 22 accommodates a part of the plurality of terminal fittings 3 from the fitting port 21 inward. It is formed so as to fit the mating connector. The terminal holding wall 23 is formed so as to face the fitting port 21 in the front-rear direction among the walls forming the housing space 22 of the housing 2, and a plurality of terminal fittings 3 are press-fitted and held. A terminal press-fit hole 23a is formed.

  The terminal fitting 3 has a tip 35 extending in the extending direction toward the circuit board 5. The terminal fitting 3 is composed of a conductive metal material or the like as a whole, and is a wire rod terminal made of a rectangular wire formed in a rod shape as shown in FIG. The terminal fitting 3 is provided to the housing 2 corresponding to each terminal press-fitting hole 23a, and is formed in a rectangular column shape corresponding to each terminal press-fitting hole 23a and the through hole 5a of the circuit board 5, A cross-sectional shape in a plane orthogonal to the extending direction is formed in a rectangular shape. Each terminal fitting 3 corresponds to each terminal fitting of the mating connector, and holds a part of the terminal fitting 3 protruding from the terminal holding wall 23 toward the accommodating space 22 so that the terminals are connected to each other. Yes. Each terminal fitting 3 has a base material 3a formed with two layers of plating layers consisting of an inner layer 3b and an outer layer 3c. As shown in FIG. 8, a main body 31, a connection 32, and a dowel 33 and a press-fitting portion 34.

  As shown in FIG. 8, the inner layer 3 b is formed on the surface of the base material 3 a, and contains a first metal whose wettability is lower than that of the metal that is the main component of the solder 6 as a main component. Further, as shown in FIG. 8, the outer layer 3c is formed on the surface of the inner layer 3b, and mainly contains a second metal having higher wettability than the first metal. The base material 3a and the outer layer 3c are separated by the inner layer 3b. The main component of the solder 6 in the present embodiment is tin (Sn), for example, and the base material 3a is, for example, copper (Cu) as the main component. In the inner layer 3b, the first metal as the main component is, for example, nickel (Ni), and is formed by plating on the surface of the base material 3a. In the outer layer 3c, the second metal as the main component is, for example, tin (Sn), and is formed by plating on the surface of the inner layer 3b. In addition, the outer layer 3c in this invention is a plating layer provided in the outermost layer.

  The main body 31 is provided on the rear end 36 side in the extending direction of the terminal fitting 3. The main body 31 in this embodiment is on the rear end 36 side of the dowel 33. As shown in FIG. 4, the connection portion 32 is provided on the distal end 35 side of the terminal fitting 3 in the extending direction, and is formed so as to be electrically connected to the circuit board 5 via the solder 6. ing. The connecting portion 32 in the present embodiment is closer to the tip 35 than the dowel 33. As shown in FIG. 4, the dowel 33 is provided on the rear end 36 side in the extending direction from the connection portion 32. For example, as shown in FIG. 5, the dowel 33 is composed of protrusions and steps having a relatively simple structure. The dowel 33 has a surface portion 33a, a deformed portion 33b, and an internal exposed surface 33c. In the present embodiment, the dowel 33 is continuous with the main body 31 on the rear end 36 side in the extending direction and continuous with the connecting portion 32 on the front end 35 side in the extending direction.

  The surface portion 33a is a portion that is not processed at the time of press molding in the dowel 33, and is formed to face in the facing direction as shown in FIG. In the surface portion 33 a, the outer layer 3 c is exposed, the rear end 36 side in the extending direction is continuous with the main body portion 31, and the front end 35 side in the extending direction is continuous with the connecting portion 32. The deformation portion 33b is a portion that is processed at the time of press molding in the dowel 33, and is a press surface and a protruding portion in the dowel 33 as shown in FIG. The deformation portion 33b is formed so as to protrude in the width direction with the surface portion 33a interposed therebetween in the width direction. The pair of deformed portions 33b is formed such that the combined length of the pair of deformed portions 33b in the width direction is larger than the diameter of the through hole 5a. That is, the deforming portion 33 b is formed such that a part of the extending direction on the tip 35 side comes into contact with the upper surface of the circuit board 5. The deformation portion 33b in the present embodiment is formed in an inclined shape so that the combined length of the pair of deformation portions 33b in the width direction decreases from the front end 35 side to the rear end 36 side in the extending direction. .

The internal exposed surface 33c is a portion where the inner layer 3b is exposed during press molding in the dowel 33, and as shown in FIG. 5, one end of both ends in the facing direction is connected to the surface portion 33a, and the other end is the deformed portion 33b. Are connected to each other. That is, the first metal is exposed at the internal exposed surface 33c. The internal exposed surface 33c has an inhibitory surfaces 33c _1, as shown in FIG. 5, is provided on the rear end 36 side of the extending direction of the pair of inner exposed surface 33c. The pair of inhibition surfaces 33c ₁ are formed toward the outside in the width direction. In the present embodiment, the pair of obstructing surfaces 33c ₁ are tapered toward the rear end 36 side in the extending direction, and are curved so as to be away from each other, whereby the rear end 36 side in the extending direction. Is formed so as to be connected to a surface of the terminal fitting 3 facing in the width direction.

  The press-fit portion 34 is provided on the rear end 36 side in the extending direction from the dowel 33 and is press-fitted into the terminal press-fit hole 23 a of the housing 2. The press-fit portion 34 in the present embodiment has the same shape as the dowel 33, and the length of the pair of deformed portions in the width direction is formed larger than the diameter of the terminal press-fit hole 23a. Moreover, it forms in the inclined shape so that the length which combined a pair of deformation | transformation part in the width direction may become small toward the rear end 36 side in the extending direction from the front-end | tip 35 side. The dowel 33 and the press-fit portion 34 in the present embodiment can be molded by one press molding machine.

  As shown in FIG. 3, the aligning plate 4 is made of a resin and is formed in an elongated flat plate shape. The aligning plate 4 can be fixed to the housing 2 by providing a structure for press-fitting or locking to the housing 2, and is arranged along the bottom surface of the housing 2 while being attached to the housing 2. The The aligning plate 4 is formed with a plurality of positioning holes 41 penetrating the front and back, and the terminal fittings 3 can be inserted into the positioning holes 41.

  The circuit board 5 constitutes an electronic circuit on which various electronic components (not shown) are mounted and electrically connected. The circuit board 5 is made of, for example, an insulating material such as epoxy resin, glass epoxy resin, paper epoxy resin, or ceramic, and a wiring pattern (not shown) is printed with a conductive material such as copper. The circuit board 5 has a through hole 5a and a conductive portion 5b.

  As shown in FIG. 6, the through holes 5 a are provided corresponding to the respective terminal fittings 3, and are formed so that the terminal fittings 3 are inserted into predetermined positions on the circuit board 5. The diameter of each through hole 5a is set to be smaller than the combined length of the pair of deformed portions 33b in the width direction. As shown in FIG. 6, the conductive portion 5b is formed on the inner peripheral surface of the through hole 5a and the opening edge portion with a conductive material such as copper, and is electrically connected to the circuit pattern formed on the circuit board 5. Connected.

  Next, the manufacturing method of the terminal metal fitting 3 of this embodiment is demonstrated. First, the terminal fitting 3 is molded from a copper plate by press molding. At the time of this molding, the terminal fitting 3 is formed in a straight line, but the dowel 33 is not formed. Next, nickel base plating is applied to the entire terminal fitting 3, and tin plating is applied to the entire terminal fitting 3. Thus, two plating layers composed of the inner layer 3a and the outer layer 3b are formed on the base material 3a. Next, the surface portion facing in the facing direction on the tip 35 side in the extending direction of the terminal fitting 3 is pressed in the facing direction, thereby forming the deformed portion 33b protruding outward in the width direction, An internal exposed surface 33c is formed. Thereby, dowels 33 are formed on the terminal fitting 3. Next, the press fitting part 34 is formed by pressing the surface part which faces in the opposing direction in the rear end 36 side of the extending direction of the terminal metal fitting 3 in the opposing direction.

  Next, a method for assembling the connector 1 of this embodiment will be described. First, the press-fitting portions 34 provided on the rear end 36 side of each terminal fitting 3 formed in a straight shape are press-fitted into the respective terminal press-fitting holes 23 a of the housing 2. Next, the front end 35 side of each terminal fitting 3 is bent 90 degrees so as to be parallel to the lower direction, thereby projecting from the bottom surface of the housing 2. Next, the distal end 35 side of each terminal fitting 3 is inserted into each positioning hole 41 of the aligning plate 4, and the connecting portion 32 and the dowel 33 of each terminal fitting 3 are inserted into each positioning hole 41, thereby The lining plate 4 is fixed to the housing 2 and the assembly of the connector 1 is completed.

  Next, a method for mounting the connector 1 on the circuit board 5 will be described. First, as shown in FIG. 6, the cream-like solder 6 is applied to the circuit board 5 by printing the cream-like solder 6 on the opening of the through-hole 5a on the upper surface of the circuit board 5 with a screen printer. To do. Next, each terminal fitting 3 is inserted into each through hole 5a. Here, as shown in FIG. 7, the dowels 33 of the respective terminal metals 3 abut on the upper surface of the circuit board 5. Next, the circuit board 5 is passed through a reflow furnace (not shown) to perform reflow soldering. Here, the cream-like solder 6 is melted by the heat of the reflow furnace, and the flux contained in the solder 6 spreads wet on the outer layer 3 c of each terminal fitting 3. At this time, since nickel having lower wettability than tin, which is the main component of the solder 6, is exposed on the internal exposed surface 33c of each dowel 33, each dowel 33 suppresses the sucking up of the solder 6. be able to. In addition, since the outer layer 3c mainly composed of tin having higher wettability than nickel is exposed at the connection portions 32 of each terminal fitting 3, nickel is not exposed at each connection portion 32. The solder 6 tends to accumulate.

  According to the connector 1 described above, the dowel 33 includes the pair of deformed portions 33b that sandwich the surface portion 33a and extend in the width direction orthogonal to the extending direction and the opposing direction. The total length of the deformed portions 33b is larger than the diameter of the through hole 5a. With this shape, the pair of deformed portions 33b of the dowel 33 are in contact with the circuit board 5 respectively, so that the terminal allowance from the circuit board 5 to the tip 35 of the terminal fitting 3 can be kept constant. Also, the first metal having a lower wettability than the metal that is the main component of the solder 6 is exposed on the internal exposed surface 33c of the dowel 33, and the second metal having a higher wettability than the first metal is exposed on the surface of the terminal fitting 3. A plurality of plating layers composed of the outermost layer mainly composed of the above metal are formed. Thereby, the sucking up of the solder 6 in the dowel 33 can be suppressed. From the above, variation in the wettability of the solder 6 in the connection portion 32 is suppressed, and even when the plurality of terminal fittings 3 are mounted on the circuit board 5 at the same time, the internal exposure of the circuit board 5 and the dowel 33 is performed. It becomes possible to keep the relative position to the surface 33c constant. Further, the terminal fitting 3 can be reliably connected to the conductive portion 5b of the circuit board 5, and even when the plurality of terminal fittings 3 are mounted on the circuit board 5 at the same time, The sucking up becomes uniform, and the deterioration of the connection reliability with the terminal fitting 3 circuit board 10 can be suppressed.

  Further, the internal exposed surface 33c is formed by pressing, but the second metal having high wettability is formed on the terminal fitting 3 while exposing the first metal having low wettability to the internal exposed surface 33c by the pressing process. Therefore, the connection part 32 and the internal exposed surface 33c can be manufactured by a conventional plating process and pressing process.

  Further, the solder 6 is made of a metal mainly composed of tin, the first metal is made of nickel, and the second metal is made of tin, so that the outer layer 3c which is the outermost layer of the plating layer in the connection portion 32 is mainly made of tin. A metal as a component is formed, and nickel is exposed on the internal exposed surface 33c. Therefore, it is possible to manufacture the terminal fitting 3 in which the conventional electrical performance is maintained and the internal exposed surface 33c and the connection portion 32 are formed of the conventional material.

Further, since the inhibition surfaces 33c ₁ provided on the pair of internal exposed surfaces 33c are formed so as to go outward in the width direction, the inhibition surfaces 33c prevent the solder 6 from being sucked to the rear end 36 side in the extending direction. ₁ will block. Therefore, the sucking up of the solder 6 in the dowel 33 can be further suppressed.

  Moreover, in the said embodiment, although the base material 3a of each terminal metal fitting 3 consists of copper, it is not limited to this shape, For example, the metal material which consists of a copper alloy and iron may be sufficient.

  Moreover, in the said embodiment, although the inner layer 3b of each terminal metal fitting 3 consists of nickel, it is not limited to this shape, If it is a metal whose wettability is lower than the metal which is the main component of the solder 6, A metal material other than nickel may be used. For example, a metal material made of a nickel alloy may be used.

  Moreover, in the said embodiment, although the outer layer 3c of each terminal metal fitting 3 consists of tin, it is not limited to this form, It is a metal with higher wettability than the 1st metal which is the main component of the inner layer 3b. If it exists, it may be a metal material other than tin, for example, a metal material made of a tin alloy or gold.

  In the above embodiment, the inner layer 3b is exposed on the pair of internal exposed surfaces 33c. However, the present invention is not limited to this configuration. For example, the inner layer 3b and the base material 3a may be exposed.

Further, in the above embodiment, a pair of inner exposed surface 33c is is provided with the inhibiting surface 33c ₁ to the rear end 36 side of the extending direction, is not limited to this shape, the inhibition surface 33c ₁ It does not have to be provided.

Further, in the above embodiment, a pair of inhibiting surface 33c ₁ is curved so as to go away from each other, it is not limited to this shape, for example, in the extending direction rear end 36 side of the The end portions are bent and extended so as to be connected to the surface facing the width direction of the terminal fitting 3, so that the pair of obstructing surfaces 33 c ₁ are formed to face the direction toward the rear end 36 in the extending direction. May be.

  Moreover, in the said embodiment, each terminal metal fitting 3 is formed with two plating layers including the inner layer 3b and the outer layer 3c on the base material 3a. However, it is not limited to this form, For example, the plating layer which consists of three layers or more may be sufficient. In the case of this form, one of the inner layers 3b includes a layer mainly composed of a first metal that has lower wettability than the metal that is the main component of the solder 6, and the outer layer 3c that is the outermost layer includes the first layer. Any layer having a second metal that has higher wettability than the above metal as a main component may be used.

  Moreover, in the said embodiment, although a pair of deformation | transformation part 33b protrudes toward the outer side in the width direction, it is not limited to this shape, For example, you may extend in the opposing direction.

  Moreover, in the said embodiment, although the press-fit part 34 is the same shape as the dowel 33, it is not limited to this shape, The shape from which the press-fit part 34 and the dowel 33 differ may be sufficient.

DESCRIPTION OF SYMBOLS 1 Connector 2 Housing 3 Terminal metal fitting 3b Inner layer 3c Outer layer 32 Connection part 33 Dowel 33a Surface part 33b Deformation part 33c Internal exposure surface 33c ₁ Obstruction surface 35 Front end 36 Rear end 4 Alignment plate 5 Circuit board 5a Through hole 5b Conductive part 6 Solder

Claims (3)

A terminal fitting whose tip extends in the extending direction toward the circuit board,
A connecting portion that is provided on the front end side and electrically connected to the conductive portion formed on the inner peripheral surface and the opening edge of the through hole of the circuit board so as to be conductive through solder;
A dowel provided on the rear end side that is opposite to the front end side in the extending direction from the connecting portion;
An inner layer mainly composed of a first metal having lower wettability than the metal which is the main component of the solder, and an outermost layer mainly composed of a second metal having higher wettability than the first metal. Including a plating layer;
Have
The dowels are
A surface portion facing in the facing direction orthogonal to the extending direction;
A pair of deformed portions sandwiching the surface portion in the width direction perpendicular to the extending direction and the opposing direction and projecting in the width direction;
One end of both ends in the facing direction is connected to the surface portion, and the other end is connected to the deformed portion, an internal exposed surface,
Have
The pair of deformed portions is formed such that the combined length of the pair of deformed portions in the width direction is larger than the diameter of the through hole.
The pair of internal exposed surfaces have at least the first metal exposed,
A terminal fitting characterized by that. The terminal fitting according to claim 1,
The solder is mainly composed of tin,
The first metal is nickel;
The second metal is tin;
Terminal fitting. In the terminal metal fitting according to claim 1 or 2,
The pair of internal exposed surfaces are each formed with an obstruction surface on the rear end side in the extending direction,
The inhibition surface is formed outward in the width direction.
Terminal fitting.