JP2015219975A - Connector terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connector terminal capable of reducing an Ag usage amount and improving the connection reliability at a pressure-bonding part, compared with the conventional art.SOLUTION: A connector terminal 1 comprises: a contact part 11 with an electric contact 110 to be electrically contacted with a mating connector terminal; and a pressure-bonding part 13 for pressure-bonding a conductor of an electric wire. In the connector terminal 1, Cu or a Cu alloy is used as a basic material 10. The electric contact 110 has, on the basic material 10, an Ag-Sn alloy layer 111, and an Ag layer 112 arranged on a surface of the Ag-Sn alloy layer 111 and exposed on the outermost surface of the electric contact 110. The pressure-bonding part 13 has, on the basic material 10, an Sn layer or an Sn alloy layer 113 exposed on the outermost surface of the pressure-bonding part 13.

Description

  The present invention relates to a connector terminal.

  In recent years, with the spread of hybrid vehicles and electric vehicles, high-current connector terminals are used for power supply lines for supplying power to motors and the like. This type of connector terminal generates a large amount of heat because a large current flows. In addition, since the connector terminal has a large terminal size according to the current capacity, the fitting force with the mating connector terminal during connector fitting tends to increase. Therefore, it is desired that the connector terminal has high heat resistance and improved wear resistance by reducing the friction coefficient.

  For example, in Patent Document 1, as a connector terminal having high heat resistance and a low friction coefficient, a base material made of Cu or a Cu alloy for forming a terminal, and an Ag—Sn alloy layer covering the base material surface, A connector terminal having an Ag-Sn alloy layer and an Ag layer exposed on the outermost surface of the terminal is disclosed.

JP 2014-5549 A

  However, in the conventional connector terminal, the Ag layer is exposed on the entire outermost surface of the terminal. Therefore, the connector terminal has a problem that the amount of expensive Ag used is increased. Moreover, in the connector terminal which has the crimping | compression-bonding part for crimping | bonding the conductor of an electric wire, when the Ag layer is exposed to all the outermost surfaces of a terminal, the following problem will arise. That is, Ag is a metal that easily adheres. Therefore, during the crimping of the crimping part, strong adhesion tends to occur between the Ag layer of the crimping part and the crimping jig. As a result, the caulking shape of the crimping portion is deteriorated, and this may cause a decrease in connection reliability of the crimping portion.

  The present invention has been made in view of the above background, and it is desirable to provide a connector terminal that can reduce the amount of Ag used and can improve the connection reliability in the crimping portion as compared with the conventional case. It is what.

One aspect of the present invention includes a contact portion having an electrical contact for making electrical contact with a mating connector terminal, and a crimp portion for crimping a conductor of an electric wire, and Cu or a Cu alloy is used as a base. A connector terminal made of a material,
The electrical contact has, on the base material, an Ag—Sn alloy layer, and an Ag layer that is disposed on the surface of the Ag—Sn alloy layer and exposed on the outermost surface of the electrical contact,
The crimp part has a Sn layer or an Sn alloy layer exposed on the outermost surface of the crimp part on the base material.

  In the connector terminal, the electrical contact to be brought into electrical contact with the mating connector terminal is arranged on the surface of the Ag—Sn alloy layer and the Ag—Sn alloy layer on the base material and on the outermost surface of the electrical contact. And an exposed Ag layer. Therefore, the contact resistance of the connector terminal with the counterpart connector terminal can be lowered by the Ag layer exposed on the outermost surface of the electrical contact. Moreover, since the said connector terminal has an Ag-Sn alloy layer, thermal stability can improve and it can make the heat resistance of an electrical contact high. Moreover, since the Ag-Sn alloy layer having higher hardness than the Ag layer is disposed below the Ag layer, the connector terminal has a reduced friction coefficient on the surface of the Ag layer, and wear resistance of the electrical contacts. Can be improved.

  Here, as for the said connector terminal, the crimping | compression-bonding part has Sn layer or Sn alloy layer exposed to the outermost surface of a crimping | compression-bonding part on a base material. That is, since the connector terminal does not have an Ag layer in the crimping portion, the area of use of Ag is reduced compared to the conventional case. Therefore, the connector terminal can reduce the amount of Ag used compared to the conventional case, and can contribute to a reduction in manufacturing cost. Furthermore, Sn or Sn alloy exposed on the outermost surface of the crimping part is a metal that is less likely to adhere than Ag. For this reason, the connector terminal is less likely to cause adhesion between the Sn layer or Sn alloy layer of the crimping part and the crimping jig during crimping, and the crimping part is connected due to the deterioration of the crimping shape of the crimping part. There is no risk of lowering reliability. As a result, the connector terminal can improve the connection reliability of the crimping portion.

FIG. 3 is an explanatory diagram schematically illustrating a configuration of a connector terminal according to the first embodiment. FIG. 6 is an explanatory diagram for explaining an example of a method for manufacturing the configuration of the connector terminal according to the first embodiment. It is explanatory drawing which showed typically the structure of the terminal for connectors of Example 2. FIG. It is explanatory drawing which showed typically the structure of the terminal for connectors of Example 3. FIG.

  The connector terminal includes a contact portion having an electrical contact for making electrical contact with the mating connector terminal, and a crimping portion for crimping the conductor of the electric wire. Specifically, the contact portion and the crimping portion can be a connecting portion that couples the contact portion and the crimping portion.

  As the shape of the connector terminal, for example, the shape of a known female terminal, male terminal, relay terminal, or the like can be applied. Specifically, the connector terminal includes, for example, a cylindrical contact portion provided with an elastic contact piece for elastic contact with a tab portion of a male terminal, and a pair of crimps for crimping a conductor of an electric wire. It can comprise as a female terminal etc. which have the crimping | compression-bonding part provided with the piece. In this case, the electrical contact can be configured to be included in a protrusion formed on the elastic contact piece. The connector terminal includes, for example, a contact portion including a tab portion having a flat shape, a pin shape, or the like that elastically contacts the elastic contact piece of the female terminal, and a pair of crimps for crimping the conductor of the electric wire. It can comprise as a male-type terminal etc. which have the crimping | compression-bonding part provided with the piece. In this case, the electrical contact can be included in the tab portion.

  The connector terminal uses Cu or a Cu alloy as a base material. That is, the connector terminal is entirely formed based on Cu or Cu alloy.

  In the connector terminal, the electrical contact has at least an Ag—Sn alloy layer and an Ag layer disposed on the surface of the Ag—Sn alloy layer and exposed on the outermost surface of the electrical contact on the base material. Yes. That is, in the electrical contact, the surface of the Ag layer is the outermost surface of the electrical contact, and the Ag—Sn alloy layer is disposed so as to be in contact with the lower surface of the Ag layer. The electrical contact may have other layers such as a Ni layer, a Ni alloy layer, and an Ag layer between the Ag—Sn alloy layer and the base material. In addition, the lower surface of the Ag-Sn alloy layer and the surface of the base material may be in contact with each other without having another layer between the Ag-Sn alloy layer and the base material.

  The thickness of the Ag layer can be set to about 0.5 μm to 3 μm from the viewpoints of ensuring good electrical conductivity and reducing the manufacturing cost by reducing the amount of Ag used. The thickness of the Ag—Sn alloy layer can be about 1 μm to 9 μm from the viewpoint of ensuring good heat resistance and ensuring the effect of reducing the friction coefficient of the Ag layer surface.

  In the connector terminal, the crimping part has at least an Sn layer or an Sn alloy layer exposed on the outermost surface of the crimping part on the base material. Specifically, the Sn layer or the Sn alloy layer may be present at least on the jig contact surface that contacts the crimping jig when the crimping portion is crimped. The Sn layer or the Sn alloy layer is preferably also present on the conductor contact surface in contact with the conductor from the viewpoint of obtaining a good electrical connection with the conductor. The pressure-bonding part can have other layers such as a Ni layer and a Ni alloy layer, for example, between the Sn layer or the Sn alloy layer and the base material. In addition, the lower surface of the Sn layer or the Sn alloy layer may be in contact with the surface of the base material without having another layer between the Sn layer or the Sn alloy layer and the base material.

  The thickness of the Sn layer or the Sn alloy layer can be set to about 0.1 μm to 10 μm from the viewpoint of improving the connection reliability at the crimping portion and ensuring the corrosion resistance.

  The connector terminal preferably further includes a Ni layer or a Ni alloy layer between the Ag—Sn alloy layer and the base material and between the Sn layer or the Sn alloy layer and the base material.

  In this case, when the temperature of the connector terminal rises due to heat generated by a large current, or when the connector terminal is exposed to a high temperature environment, the base material component Cu diffuses to the outermost surface of the terminal and oxidizes. It becomes easy to suppress that a contact resistance increases by forming a thing. The thickness of the Ni layer or the Ni alloy layer can be about 0.5 μm to 2 μm from the viewpoint of effectively suppressing the diffusion of Cu.

  In the connector terminal, the Ag—Sn alloy layer and the Ag layer in the electrical contact can be configured to extend to at least the peripheral portion of the electrical contact in the contact portion. In addition, the peripheral part of an electrical contact means the surface part around an electrical contact among the parts except the electrical contact in a contact part.

  In this case, the electrical contact and the peripheral portion of the electrical contact have an Ag—Sn alloy layer and an Ag layer disposed on the surface of the Ag—Sn alloy layer on the base material. Therefore, it is possible to more reliably reduce the contact resistance with the mating connector terminal, improve the heat resistance of the electrical contact, and improve the wear resistance of the electrical contact.

  In the connector terminal, the contact portion includes an Ag—Sn alloy layer and an Ag layer disposed on the surface of the Ag—Sn alloy layer and exposed on the outermost surface of the contact portion on the base material. be able to.

  In this case, the Ag-Sn alloy layer is disposed so that the surface of the Ag layer is the outermost surface and is in contact with the lower surface of the Ag layer, not only in the contact portion but also in most of the electrical contact. . Such a structure can be formed relatively easily using an electroplating method. Therefore, in this case, a connector terminal excellent in manufacturability is obtained.

  In the connector terminal, the base material, the Sn layer, the Sn alloy layer, the Ag layer, and the Ag—Sn are provided on the jig contact surface that contacts the crimping jig when the crimping portion is crimped and on the outermost surface of the terminal portion other than the electrical contacts. At least one selected from the group consisting of an alloy layer, a Ni layer, and a Ni alloy layer may be exposed.

  As a case where the base material is exposed on the outermost surface of the terminal portion, for example, a cut surface generated at the time of manufacturing the connector terminal can be exemplified as a typical example.

  The structure in which the Ag—Sn alloy layer and the Ag layer are sequentially laminated on the base material is, for example, a laminated structure in which Ag plating, Sn plating, and Ag plating are laminated in this order on the base material using an electroplating method. After the multilayer plating layer containing is formed, it can be formed by heat treatment. The structure in which the Sn layer or the Sn alloy layer is laminated on the base material is, for example, by using an electroplating method, applying Sn plating or Sn alloy plating on the base material, and performing heat treatment as necessary. Can be formed. In addition, when a Ni or Ni alloy layer is formed on a base material, an electroplating method may be applied as described above.

  In addition, each structure mentioned above can be arbitrarily combined as needed, in order to acquire each effect etc. which were mentioned above.

  Hereinafter, the connector terminal of the embodiment will be described with reference to the drawings. In addition, about the same member, it demonstrates using the same code | symbol.

Example 1
The connector terminal of Example 1 will be described with reference to FIGS. 1 and 2. As shown in FIGS. 1 and 2, the connector terminal 1 of this example includes a contact portion 11 having an electrical contact 110 for making electrical contact with a mating connector terminal (not shown), and an electric wire (not shown). And a crimping portion 13 for crimping the conductor, and Cu or Cu alloy is used as the base material 10. In this example, specifically, between the contact portion 11 and the crimping portion 13 is a connecting portion 12 that couples the contact portion 11 and the crimping portion 13.

  In this example, the connector terminal 1 is specifically a female terminal. The connector terminal 1 is used for a connector (not shown) of an automobile wire harness. Although not shown in detail, the connector terminal 1 more specifically has a cylindrical portion having an insertion opening for inserting a tab portion of a male terminal as a counterpart connector terminal to be electrically connected. doing. An elastic contact piece formed by folding the bottom plate inward and rearward is provided inside the tubular portion. The elastic contact piece applies an upward force to the tab portion of the inserted male terminal. The tab portion of the male terminal is pressed against the inner surface of the tubular ceiling plate by the elastic contact piece. Thereby, the tab part of a male terminal is hold | maintained in the clamping state between an elastic contact piece and the inner surface of a ceiling board. An embossed portion is formed at a portion of the elastic contact piece that contacts the male terminal. The embossed portion is a protrusion formed by raising the surface of the elastic contact piece in a hemispherical shape. The embossed portion comes into contact with the tab portion of the male terminal in the vicinity of the top portion. In this example, a portion of the embossed portion that substantially contacts the male terminal corresponds to the electrical contact. Moreover, in the connector terminal 1, the crimping | compression-bonding part 13 consists of a pair of crimping piece more specifically.

  In the connector terminal 1, the electrical contact 110 is disposed on the base material 10 on the surface of the Ag—Sn alloy layer 111 and the Ag—Sn alloy layer 111 and exposed to the outermost surface of the electrical contact 110. And have.

  In this example, specifically, the Ag—Sn alloy layer 111 and the Ag layer 112 are extended to at least the peripheral portion of the electrical contact 110 in the contact portion 11. More specifically, the connector terminal 1 of this example is disposed on the base material 10 in the contact portion 11 on the surface of the Ag—Sn alloy layer 111 and the Ag—Sn alloy layer 111 and the contact portion 11. The structure has an Ag layer 112 exposed on the outermost surface. That is, in the connector terminal 1 of this example, not only the electrical contact 110 in the contact portion 11 but also most of the contact portion 11 excluding the electrical contact 110 has the surface of the Ag layer 112 as the outermost surface. An Ag—Sn alloy layer 111 is disposed in contact with the lower surface. Therefore, in the contact portion 11, the Ag contacts 112 in the portion excluding the electrical contacts 110 and the electrical contacts 110 are continuous with each other. Similarly, in the contact portion 11, the Ag—Sn alloy layers 111 in a portion excluding the electrical contact 110 and the electrical contact 110 are continuous with each other.

  In the connector terminal 1, the crimping part 13 has an Sn layer 113 exposed on the outermost surface of the crimping part 13 on the base material 10. The Sn layer 113 can be changed to a Sn alloy layer. In this example, specifically, the Sn layer exists on both the jig contact surface that contacts a crimping jig (not shown) and the conductor contact surface that contacts the conductor when the crimping portion 13 is crimped. .

  In the connector terminal 1, the connecting portion 12 has at least a Sn layer 113 exposed on the outermost surface of the connecting portion 12 on the base material 10. The Sn layer 113 can be changed to a Sn alloy layer. In this example, specifically, the Sn layer 113 of the connecting portion 12 is continuous with the Sn layer 113 of the crimping portion 13.

  The connector terminal 1 of this example further includes a Ni layer 114 between the Ag—Sn alloy layer 111 and the base material 10 and between the Sn layer 113 and the base material 10. The Ni layer 114 can be changed to a Ni alloy layer. In addition, each Ni layer 114 in the contact part 11, the crimping | compression-bonding part 13, and the connection part 12 is mutually continuous.

  In the connector terminal 1 of this example, the thickness of the Ag layer 112 is specifically 1 μm. Specifically, the thickness of the Ag—Sn alloy layer 111 is 4 μm. Specifically, the thickness of the Sn layer 113 is 1.4 μm. Specifically, the thickness of the Ni layer 114 is 1 μm. The connector terminal 1 of this example is configured by punching a plate-shaped terminal material and then bending it, and the base material is exposed at the cut surface generated at the time of punching.

  Specifically, the connector terminal 1 of this example can be manufactured as follows, for example.

  A plate material using Cu or a Cu alloy as a base material 10 is prepared. Then, as shown in FIG. 2, for example, a 1 μm thick Ni plating 21 is formed on the surface of the plate material by electroplating. Next, in the plate material whose surface is covered with the Ni plating 21, for example, an Ag plating 22 having a thickness of 1.3 μm is formed on the contact portion forming portion 110 that becomes the contact portion 11 by bending after punching the terminal shape described later. . In addition, the crimping part forming part 130 which becomes the crimping part 13 by the bending process after punching the terminal shape and the connecting part forming part 120 which becomes the coupling part 12 by the bending process after punching the terminal shape are the surfaces of the Ni plating 21. Is previously masked so that the Ag plating 22 is not applied. Next, for example, a thickness of 1. is applied so as to cover the surface of the Ag plating 22 applied to the contact portion forming portion 110 and the surface of the Ni plating 21 applied to the pressure bonding portion forming portion 130 and the connecting portion forming portion 120. A 4 μm thick Sn plating 23 is formed. Next, for example, an Ag plating 24 having a thickness of 2.3 μm is formed so as to cover the surface of the Sn plating 23 in the contact portion forming unit 110 among the surface of the Sn plating 23. Note that the crimping part forming part 130 and the connecting part forming part 120 are previously masked so that the Ag plating 24 is not applied to the surface of the Sn plating 23. In this manner, a multilayer plating layer 25 having a multilayer structure as shown in FIG. 2 is formed on the base material 10. Next, for example, heat treatment (reflow treatment) is performed at 200 ° C. for 30 minutes. Next, the plate-like terminal material obtained as described above is punched into a terminal development shape and bent to obtain a predetermined connector terminal.

  By the heat treatment, the Ag—Sn alloy layer 111 is formed from the Ag plating 22, the Sn plating 23, and the Ag plating 24, and the Ag layer 24 is formed on the surface of the Ag—Sn alloy layer 111. Note that an Ag layer may be formed on the lower surface of the Ag—Sn alloy layer 111 depending on conditions. Moreover, the Sn layer 113 is formed from the Sn plating 23 by the heat treatment.

  Next, the effect of the connector terminal 1 of this example will be described.

  In the connector terminal 1, an electrical contact 110 that makes electrical contact with the mating connector terminal is disposed on the base material 10 on the surface of the Ag—Sn alloy layer 111 and the Ag—Sn alloy layer 111 and the electrical contact. And an Ag layer 112 exposed on the outermost surface of 110. Therefore, the contact resistance of the connector terminal 1 with the mating connector terminal can be lowered by the Ag layer 112 exposed on the outermost surface of the electrical contact 110. Moreover, since the connector terminal 1 has the Ag—Sn alloy layer 111, the thermal stability is increased, and the heat resistance of the electrical contact 110 can be increased. Moreover, since the Ag-Sn alloy layer 111 having a higher hardness than the Ag layer 112 is disposed below the Ag layer 112, the connector terminal 1 has a reduced friction coefficient on the surface of the Ag layer 112, and the electrical contact The wear resistance of 110 can be improved.

  Here, in the connector terminal 1, the crimp part 13 has an Sn layer 23 exposed on the outermost surface of the crimp part 13 on the base material 10. That is, since the connector terminal 1 does not have the Ag layer 110 in the crimping portion 13, the use area of Ag is reduced. Therefore, the connector terminal 1 can reduce the amount of Ag used compared to the conventional case, and can contribute to the reduction of the manufacturing cost. Furthermore, Sn exposed on the outermost surface of the crimping part 13 is a metal that is less likely to adhere than Ag. For this reason, the connector terminal 1 is less likely to cause adhesion between the Sn layer 113 of the crimping portion 13 and the crimping jig during crimping, and the crimping portion 13 is deteriorated due to the deterioration of the caulking shape. There is no risk of lowering reliability. As a result, the connector terminal 1 can improve the connection reliability of the crimping part 13.

  Further, in the connector terminal 1 of this example, the Ni layer is disposed on the surface of the base material 10. Therefore, when the temperature of the connector terminal 1 of this example rises due to heat generated by a large current or when it is exposed to a high temperature environment, Cu as a base material component diffuses to the outermost surface of the terminal and becomes an oxide. As a result, there is an advantage that it is easy to suppress an increase in contact resistance.

(Example 2)
The connector terminal of Example 2 will be described with reference to FIG.

  As shown in FIG. 3, the connector terminal 1 of this example is an example in which an Ag—Sn alloy layer 111 and an Ag layer 112 are disposed only at the portion of the electrical contact 110 in the contact portion 11. The surface of the contact portion 11 other than the electrical contact 110 is covered with the Sn layer 113. Other configurations are the same as those of the first embodiment.

  Compared with the connector terminal 1 of the first embodiment, the connector terminal 1 of this example further reduces the area of Ag used. Therefore, the connector terminal 1 of this example is advantageous in reducing the manufacturing cost by further reducing the amount of Ag used. Other functions and effects are the same as those of the first embodiment.

(Example 3)
The connector terminal of Example 3 will be described with reference to FIG.

  The connector terminal 1 of this example is an example in which the Ni layer 114 in the connector terminal 1 of Example 1 is omitted as shown in FIG. Further, in the connector terminal 1 of this example, of the surface of the contact portion 11, the electrical contact 110 and the peripheral portion 115 of the electrical contact 110 are formed on the base material 10 with the Ag—Sn alloy layer 111 and the Ag—Sn. And an Ag layer 112 disposed on the surface of the alloy layer 111. That is, in the connector terminal 1 of this example, the Ag—Sn alloy layer 111 and the Ag layer 112 are not formed on the portion outside the peripheral portion 115 of the electrical contact 110. The surface of the contact portion 11 other than the electrical contact 110 is covered with the Sn layer 113. Other configurations are the same as those of the first embodiment.

  In the connector terminal 1 of this example, the electrical contact 110 and the peripheral portion 115 of the electrical contact 110 are formed on the base material 10 on the surface of the Ag—Sn alloy layer 111 and the Ag—Sn alloy layer 111. Layer 112. Therefore, compared with the connector terminal 1 of the second embodiment, the connector terminal 1 of the present example more reliably reduces the contact resistance with the mating connector terminal, improves the heat resistance of the electrical contact, and improves the wear resistance of the electrical contact. Can be. Moreover, compared with the connector terminal 1 of the first embodiment, the use area of Ag is further reduced. Therefore, the connector terminal 1 of this example is advantageous in reducing the manufacturing cost by further reducing the amount of Ag used. Other functions and effects are the same as those of the first embodiment except for the functions and effects of the Ni layer 114.

  As mentioned above, although the Example of this invention was described in detail, this invention is not limited to the said Example, A various change is possible within the range which does not impair the meaning of this invention.

DESCRIPTION OF SYMBOLS 1 Connector terminal 10 Base material 11 Contact part 13 Crimp part 110 Electrical contact 111 Ag-Sn alloy layer 112 Ag layer 113 Sn layer or Sn alloy layer

Claims (4)

It has a contact part having an electrical contact for making electrical contact with the mating connector terminal, and a crimp part for crimping the conductor of the electric wire, and is a connector terminal using Cu or Cu alloy as a base material. There,
The electrical contact has an Ag-Sn alloy layer on the base material, and an Ag layer that is disposed on the surface of the Ag-Sn alloy layer and exposed on the outermost surface of the electrical contact
The connector terminal, wherein the crimping part has an Sn layer or an Sn alloy layer exposed on the outermost surface of the crimping part on the base material.   A Ni layer or a Ni alloy layer is further provided between the Ag-Sn alloy layer and the base material, and between the Sn layer or the Sn alloy layer and the base material. Item 2. A connector terminal according to Item 1.   The base material, the Sn layer, the Sn alloy layer, the Ag layer, and the Ag− are provided on the jig contact surface that contacts the crimping jig when the crimping portion is crimped and the outermost surface of the terminal portion other than the electrical contact. The connector terminal according to claim 2, wherein at least one selected from the group consisting of an Sn alloy layer, the Ni layer, and the Ni alloy layer is exposed.   The connector terminal according to any one of claims 1 to 3, wherein the Ag-Sn alloy layer and the Ag layer are extended to at least a peripheral portion of the electrical contact in the contact portion. .

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