JP2014022082A - Connector terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a connector terminal in which a metal coating layer is formed only at a required part on a surface of a basic material formed of copper or copper alloy, and that is manufactured at low cost.SOLUTION: A connector terminal is formed of a clad material obtained by coating a part of a surface of a basic material formed of copper or copper alloy, and bonding a coating layer formed of a metal different from the basic material to the basic material by a clad method. The outermost surface of the coating layer can be formed of tin, silver, gold, or the like. Such a case that a plurality of coating layers whose outermost surfaces are formed of metals different from each other are formed in the different regions is especially preferable.

Description

  The present invention relates to a connector terminal, and more particularly to a connector terminal in which a coating layer is formed on the surface of a base material made of copper or a copper alloy.

  Conventionally, connector terminals used for electric wiring for automobiles are generally formed from a base material made of copper or a copper alloy. Oxide is easily formed on the surface of copper or copper alloy, so that the contact resistance increases when copper or copper alloy is exposed on the outermost surface at a place where it is in electrical contact with another conductive member. Connection reliability decreases due to instability. In order to avoid this, metal plating is often applied to the surface of the copper base material. Tin is the most common plating metal. A relatively hard insulating tin oxide film is formed on the outermost surface of the tin plating layer. However, the tin oxide film is broken by a weak force, and the soft tin layer is easily exposed. It is formed. In particular, when high connection reliability is required or when connector terminals are used in a high temperature environment, the resistance value is small and it is difficult to oxidize even at high temperatures. A plating layer is used.

  FIG. 4 shows the structure of a typical connector terminal, where contact resistances 3a1, 3b1, which are in electrical contact with the counterpart terminal, and wire conductors are required to improve connection reliability by reducing or stabilizing contact resistance. Only the wire barrels 3a2 and 3b2 to be connected by caulking. It is not necessary to apply plating for improving connection reliability in other locations. As a partial plating method for forming plating only on necessary portions in these connector terminals, for example, as disclosed in Patent Document 1, plating is performed in a state where portions that do not require plating are covered with a masking tape. There is. Alternatively, there is a method in which a plating layer is formed only on a portion immersed in the plating solution by controlling the surface of the plating solution.

Japanese Patent Laid-Open No. 7-173672

  In the partial plating method using a masking tape, a process of attaching a masking tape before plating and a peeling process after plating are required, which increases the number of processes and increases the manufacturing cost. Further, when plating layers of different metal types are formed at different locations, such as a contact portion and a wire barrel, the number of processes and cost increase further as the types of plating layers increase.

  On the other hand, in the method of limiting the plating location by controlling the liquid level, the location where the plating is formed can be controlled only by the unit of the portion immersed in the plating solution and the portion not immersed in the plating solution. If it is immersed, plating will be formed even in the unnecessary part. With this, it is difficult to form a partial plating having a fine shape or a complicated shape. In particular, such a difficulty is likely to occur when different metal plating layers are to be formed at a plurality of locations, such as a contact portion and a wire barrel. Further, since the plating layer is formed in the entire portion immersed in the plating solution, the plating layer is formed in the portion where the plating is not originally required, so that the cost of the metal material for plating increases.

  Also, if the partial plating method using masking tape application or liquid level control is used, the amount of metal material used as the plating layer can be reduced compared to the case where the plating layer is formed on the entire connector terminal. Although it has a certain cost reduction effect, it is necessary to use a sufficient amount of the plating solution to immerse the base material, which is an excess of the plating solution area relative to the area to be plated. Will be used. That is, the material cost cannot be reduced proportionally with the decrease in the area of the region where the plating layer is formed. Such a material cost problem is particularly serious when expensive gold or silver is used as a plating layer.

  The problem to be solved by the present invention is to provide a connector terminal that is manufactured at a low cost, in which a metal coating layer is formed only at a required location on the surface of a base material made of copper or a copper alloy.

  In order to solve the above problems, a connector terminal according to the present invention covers a part of a surface of a base material made of copper or a copper alloy, and a coating layer made of a metal different from the base material is formed by the cladding method. The gist is that the clad material is joined to the base material.

  Here, the outermost surface of the coating layer may be made of tin, silver, or gold.

  In addition, it is preferable that a plurality of coating layers made of metals whose outermost surfaces are different from each other are formed in different regions of the base material surface.

  Further, a coating layer made of silver or gold is formed on the outermost surface in the region including the contact portion that is in electrical contact with other conductive members, and the outermost surface is made of tin in the region including the wire barrel to which the wire conductor is connected. A coating layer can also be formed.

  According to the connector terminal concerning the said invention, the coating layer which consists of a metal different from a base material can be formed only in a required location. Even when the shape and arrangement of the required coating layer is complex, it is necessary to control the shape of the metal material for the coating layer and the arrangement on the base material when creating the cladding material. A coating layer can be selectively formed only at certain locations.

  When the coating layer is formed by the clad method, the metal material for the base material and the metal material for the coating layer may be laminated and rolled so as to have a predetermined positional relationship. Thus, both the formation of the base material and the surface treatment of the base material can be completed. Further, it is not necessary to use more metal material than is necessary for forming the coating layer in a desired area in the manufacturing process. Furthermore, an extra member such as a masking tape is not required to define the position where the coating layer is formed. With these effects, manufacturing costs can be suppressed.

  Here, high connection reliability can be realized by forming tin on the outermost surface of the coating layer. Tin is a material that is widely used as a material exposed on the outermost surface of the connector terminal.In various types of connector terminals, if the coating layer using the above-described cladding method is applied to a place where tin plating can be applied, A tin layer having a defined shape and position can be formed, and manufacturing costs can be reduced. On the other hand, silver and gold give higher connection reliability and can withstand use in a high temperature environment. These are expensive metal materials, and by forming the coating layer by the clad method, the amount of the material to be used can be suppressed to the minimum necessary, and a great cost reduction effect is achieved.

  In addition, even when a plurality of coating layers made of different metals on the outermost surface are formed in different regions, forming the cladding material with dissimilar metal materials arranged at different positions makes it possible to form a single coating layer. The connector terminal can be formed without increasing the number of steps and the cost as compared with the case of being formed from one metal species.

  Furthermore, when the outermost surface is formed with a coating layer made of silver or gold in the region including the contact portion, the contact portion is slid between the mating connection member many times by insertion and extraction, and the contact portion has a small contact area. An electrical contact having a very high connection reliability is formed between the counterpart connection member. Along with this, when the coating layer made of tin is formed on the outermost surface in the region including the wire barrel, there is no need for insertion / extraction, and even in the wire barrel having a larger contact area than the contact portion, while reducing the material cost, Good electrical contact is formed between the wire conductors.

It is the schematic which shows an example of the connector terminal concerning this invention, (a) is a side view, (b) is sectional drawing of a clamping part. It is a figure which shows an example of the clad material used for manufacture of the connector terminal concerning this invention. It is a figure which shows the correspondence of the expansion | deployment shape of the connector terminal punched out from the said clad material, and the structure of a clad material. It is a figure which shows the shape of a general connector terminal, (a) is a female connector terminal, (b) is a perspective view which shows a male connector terminal, (c) shows the fitting state of a male and female connector terminal. It is sectional drawing.

  Embodiments of the present invention will be described below in detail with reference to the drawings.

  The connector terminal according to the present invention may have any shape as a whole. For example, a female connector terminal having the same shape as that shown in FIG. 4A or a male connector terminal having the same shape as that shown in FIG. FIG. 1 is a simplified view of a female connector terminal according to an embodiment of the present invention having the same shape as that shown in FIG.

  FIG. 1A is a side view of the female connector terminal 1. In front of the connector terminal 1, a rectangular tube-shaped pinching portion 11 having an opening at the front is formed. A male connector terminal, which is a counterpart connection member, is inserted into the pinching portion 11. A wire barrel 12 is formed behind the pinching portion 11. The wire barrel 12 is formed in a substantially U-shaped cross section, and the electric wire conductor is connected to the connector terminal 1 by caulking the electric wire conductor placed thereon. Thereby, the electrical connection between an electric wire conductor and the connector terminal 1 is formed. An insulation barrel 15 is formed behind the wire barrel 12, and the insulator covering the outer periphery of the wire conductor is caulked with the insulation barrel 15, whereby the wire is firmly connected to the connector terminal 1. .

  FIG. 1B shows a cross-sectional view of the pinching portion 11. On the inner side of the bottom surface 14b of the clamping part 11, an elastic contact piece 13 having a shape folded back toward the inner side is formed. A contact portion 13 a protruding in an embossed shape is formed in the middle portion of the elastic contact piece 13. When the tab-shaped male connector terminal is inserted into the space inside the pinching portion 11, the male connector terminal comes into contact with the contact portion 13a and pushes the elastic contact piece 13 toward the bottom surface 14b. The male connector terminal is pressed against the inner surface of the ceiling surface 14 c facing the elastic contact piece 13 by the reaction force of the pressed elastic contact piece 13, and is held under pressure in the holding portion 11.

  The connector terminal 1 is made of a clad material in which a coating layer made of another metal is partially formed on the surface of a base material made of copper or a copper alloy. In the connector terminal 1, a first coating layer 16 a made of tin is formed by a clad method on the inner surface of the wire barrel 12, that is, the surface in contact with the caulked wire conductor. Further, the second covering layer 16b made of gold or silver is formed on the surface of the base material exposed in the clamping portion 11 of the contact portion 13a of the elastic contact piece 13, that is, on the surface of the base material where it contacts the male connector terminal. Is formed by a cladding method. In the place where the first coating layer 16a is formed, tin is exposed on the outermost surface, and in the place where the second coating layer 16b is formed, gold or silver is exposed on the outermost surface. Further, the base metal is exposed on the outermost surface except for the portion where the first coating layer 16a is formed and the portion where the second coating layer 16b is formed.

  Copper and copper alloys are excellent in electrical conductivity, but the surface is susceptible to oxidation, and the formation of an insulating coating tends to cause an increase in contact resistance and instability in contact with other conductive members. . However, since the coating layer made of gold, silver, or tin is formed on the surface of the contact portion 13a that contacts the male connector terminal and the surface of the wire barrel 12 that contacts the electric wire conductor, in these places, a low value is obtained. Stable contact resistance is obtained.

  Tin is soft and has a low electrical resistance, and the oxide film formed on the surface can be easily broken by the application of a load. Provide contact. By covering the surface of the wire barrel 12 connected to the wire conductor with tin, the connection reliability between the connector terminal 1 and the wire conductor is improved.

  In addition, gold and silver have an electrical resistance value smaller than that of tin and are less susceptible to oxidation and softening even in a high temperature environment, and thus provide better connection reliability. In the wire barrel 12, normally, once the wire conductor is crimped and the wire conductor is connected, the connector terminal 1 continues to be used as it is, whereas in the contact portion 13a, the contact to the clamping portion 11 is continued. By repeatedly inserting and removing the male connector terminal, the electrical connection may be formed and canceled many times. Each time the male terminal is inserted, the electrical connection needs to be formed with good reproducibility. Therefore, the contact portion 13a is required to have a higher electrical connection reliability than in the wire barrel 12. The Therefore, a coating layer made of gold or silver is formed on the contact portion 13a. Compared to gold and silver, gold is more expensive, but it has a lower electrical resistance and is less susceptible to oxidation, providing higher connection reliability.

  In order to sufficiently exhibit the effects of reduction and stabilization of contact resistance, it is desirable that the first coating layer 16a and the second coating layer 16b have a thickness of 1 μm or more in the case of tin. If gold and silver are 0.2 μm or more, sufficient connection reliability may be obtained.

  In the connector terminal 1 according to the present embodiment, the coating layers 16a and 16b are formed only on one surface of the barrel portion 12 and the contact portion 13a of the elastic contact piece 13, so that the coating layer is formed in a wider area. Compared with the case where it is, the cost which a coating | covering material requires is small. In particular, the use of expensive gold or silver, which is a noble metal, is limited to the contact portion 13a that forms an electrical contact with the male connector terminal, thereby reducing the manufacturing cost.

  The connector terminal according to the present invention is formed from a clad material 2 as shown in FIG. The clad material is obtained by laminating dissimilar metals and bonding the dissimilar metal layers by performing processes such as rolling and heat treatment.

  In the clad material 2, the first coating layer 21 made of striped tin is bonded to the surface of one side of the base material 23 made of copper or a copper alloy, and further exposed to the other surface. A second coating layer 22 made of gold or silver is joined in parallel with the one coating layer 21. Such a clad material 2 is a silver material or a gold material that forms a tin material that forms the first coating layer 21 and a second coating layer 22 in a predetermined shape at predetermined positions on both surfaces of the material for the base material 23. It can form by rolling the whole in the state which has arrange | positioned material. Since rolling means such as a roll is used in rolling, generally, in the clad material, anisotropy tends to occur in the rolled surface, and a stripe structure like the clad material 2 is formed by using the clad method. It is particularly suitable for.

  Here, the 1st coating layer 21 and the 2nd coating layer 22 are formed in the position which agree | coincides with the relative positional relationship of the wire barrel 12 of the connector terminal 1, and the contact part 13a of the elastic contact piece 13. FIG. As a result, as shown in FIG. 3, when the clad material 22 is punched and the developed shape of the connector terminal 1 is formed, the first coating layer 16a made of tin is formed on the portion that becomes the wire barrel 12, and the contact portion 13a. A second coating layer 16b made of gold or silver can be formed on the portion to be. In addition, the 1st coating layer 16a is formed in the front side of the display surface of a figure in FIG. 3, and the 2nd coating layer 16b exists in the state formed in the back side of the display surface. Further, at the position of the contact portion 13a where the second coating layer 16b is formed, an embossed protrusion is formed so as to protrude toward the back side of the display surface in the figure.

  In FIG. 3, for the sake of simplicity, only one developed shape of the connector terminal 1 is shown. However, the developed shape of the plurality of connector terminals 1 is connected to the connecting portion 17 from one long clad material 2. Can be punched in a state of being connected in parallel and aligned in parallel. In the clad material 2, the first coating layer 21 and the second coating layer 22 are formed in parallel stripes, so that the first coating layer 16a made of tin in the developed shape of all the punched connector terminals. Is formed at the position of the wire barrel 12, and the second coating layer 16b made of gold or silver is formed at the position of the contact portion 13a. Since the clad material is formed by rolling a laminated metal material at a large rolling rate, the above method is suitable for forming a large area clad material at a time and manufacturing a large number of connector terminals having the same shape. ing.

  After forming the developed shape of the connector terminal 1 of FIG. 3 by pressing, the connector terminal 1 as shown in FIG. 1 is formed by bending. That is, by separating the developed shape from the connecting portion 17 and bending a predetermined position, the rectangular tube shape of the pressing portion 11 is formed so that the side surfaces 14a and 14a rise from the bottom surface 14b toward the front side of the display surface in the figure. At the same time, the elastic contact piece 13 is folded inside the rectangular cylindrical pinching portion 11. The ceiling surface 14c is formed by overlapping two plate pieces. Further, the wire barrel 12 and the insulation barrel 15 are bent so as to have a substantially U-shaped cross-section with the side standing up toward the front side of the sheet.

  As described above, the clad material in which the coating layer is formed only at a necessary portion is rolled in a state where the metal material for forming the coating layer is arranged in a predetermined shape of the base material and laminated. Is formed. Thereby, the surface treatment process of the base material is completed simultaneously with the rolling process of the base material. Furthermore, even when a coating layer made of a plurality of metal species is formed at different positions, if a plurality of metal materials are arranged at predetermined positions before rolling, the entire coating layer can be formed by one rolling. As compared with the case where a coating layer made of a single metal species is formed, the number of steps hardly increases. On the other hand, when only a part of the terminal base material is covered with a metal layer using the partial plating method, a process such as attaching and peeling of masking tape is required, and a metal species composed of a plurality of metal species is used. When forming at different positions, the number of steps increases proportionally. That is, by using a clad material, it is possible to reduce the number of manufacturing steps and the manufacturing cost, and the effect is particularly prominent when the coating layers made of a plurality of metal species are formed at different positions. The

  In addition, since it is necessary to use a plating solution when using the plating method, even if the amount of plating material consumed is reduced by using the partial plating method, the metal that remains on the base material as a plating layer eventually It is necessary to prepare a metal material in an amount larger than the material as a plating solution. On the other hand, when forming the clad material, a material higher than the metal material that will eventually become the coating layer is not required. This also contributes to the reduction of the manufacturing cost of the connector terminal when the clad material is used.

  In addition, when a gold coating layer or a silver coating layer is formed on the surface of a base material made of copper or a copper alloy, there is a concern that diffusion of copper atoms from the base material to these coating layers may occur. The diffused copper atoms are segregated on the outermost surface of the coating layer and are subject to oxidation, which may increase the contact resistance on the surface of the coating layer. In order to prevent the diffusion of copper atoms, it is effective to form a barrier layer made of nickel or the like between the gold coating layer or silver coating layer and the base material. When such a barrier layer is formed, rolling is performed in a state where a metal material serving as a barrier layer such as nickel, gold or silver is laminated in order on a metal material serving as a base material, thereby forming a clad material. That's fine. There is no increase in the number of steps for forming the barrier layer as in the case where the plating is formed in layers.

  Not only a barrier layer but also a coating layer having a laminated structure of two or more layers, for example, a coating layer having various functions such as further reduction of contact resistance, reduction of surface friction, improvement of heat resistance, etc. Although it is considered possible to form the clad material in such a case, the clad material can be formed by rolling in a state in which the required metal materials are sequentially laminated, thereby having various laminated structures. A coating layer can be formed.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention. For example, in the above-described embodiment, the coating layer made of a different kind of metal is formed on the contact portion of the elastic contact piece and the wire barrel, but may be made of the same kind of metal.

  Moreover, what is necessary is just to form suitably if there exists a location which needs formation of a coating layer other than a contact part and a wire barrel. For example, the female connector terminal 1 in the above embodiment is in contact with the male connector terminal at two points of the contact portion 13a of the elastic contact piece 13 and the inner wall surface of the ceiling surface 14c facing the elastic contact piece 13. Or the coating layer which consists of silver is formed only in the surface of the contact part 13a among these. If a coating layer made of gold or silver is also formed on the inner wall surface of the ceiling surface 14c, the connection reliability between the connector terminals can be further improved.

  In the present invention, a base material made of copper or a copper alloy is used, but when using a base material made of another type of metal, a clad material is used in the same manner as required. It is possible to form a metal coating layer. This is because the clad material can be formed regardless of the type of metal.

DESCRIPTION OF SYMBOLS 1 Connector terminal 11 Clamping part 12 Wire barrel 13 Elastic contact piece 13a Contact part 16a, 21 1st coating layer 16b, 22 2nd coating layer 2 Clad material 23 Base material

Claims (4)

  A connector comprising a clad material that covers a part of a surface of a base material made of copper or a copper alloy, and a coating layer made of a metal different from the base material is joined to the base material by a clad method Terminal.   The connector terminal according to claim 1, wherein an outermost surface of the covering layer is made of tin, silver, or gold.   The connector terminal according to claim 1 or 2, wherein a plurality of coating layers whose outermost surfaces are made of metals different from each other are formed in different regions of the surface of the base material.   A coating layer made of silver or gold on the outermost surface is formed in a region including a contact portion that is in electrical contact with another conductive member, and a coating layer made of tin in the region containing a wire barrel to which a wire conductor is connected The connector terminal according to claim 3, wherein the connector terminal is formed.

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