JP2016113666A - Electrical element, and connector - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an inexpensive electrical element and connector that can prevent reliability degradation of a product caused by oxidation of a base material, keep an actual contact area large even for a small electric contact point of a low contact load and suppress increase of contact resistance.SOLUTION: A male terminal 32 is electrically connected with a female terminal 34 by being inserted in the female terminal 34 for contacting. A FTO thin film 36 doped with an element is installed on the smooth surface of a base material 12 at least in a region where the male terminal 32 contacts the female terminal 34 on the base material 12, wherein the element is an element that contributes to electrical conductivity.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an electrical element and a connector useful as an electrical contact for a connector.

  In general, the terminals constituting the electrical contacts for connectors are mainly made of a Cu alloy. However, if the Cu alloy is used as it is, the surface is oxidized to increase the electrical resistivity, and the reliability of the product is lowered. There is. In particular, a small terminal with a low contact load has a problem that the surface (true contact surface) where the metal contacts at the contact portion becomes very small due to the high resistance oxide film, and the contact resistance increases.

  Therefore, normally, noble metal plating such as gold or silver is formed on the surface of the Cu alloy to form a noble metal plating layer, thereby preventing the surface of the Cu alloy from being oxidized and ensuring the reliability of the product. In order to ensure corrosion resistance and wear resistance, the noble metal plating layer is provided with a certain thickness. In addition to this, even when used at a relatively large current of several tens to several hundreds of amperes, such as used for charging a storage battery of an electric vehicle, it is necessary to increase the thickness of the noble metal plating layer.

However, there is a problem that the thicker the noble metal plating layer, the higher the cost, and a technique for reducing the amount of noble metal used in the industry has been demanded.
Further, when Ag is used as the noble metal plating layer, Ag is vulnerable to corrosion such as sulfidation and has a problem that it quickly changes color. Therefore, although the anti-discoloring agent is applied to the surface of the Ag plating layer, the obtained coating film is usually very brittle and peels off due to plus molding, contact fitting, etc., and Ag discoloration cannot be effectively prevented. There was also a problem.

For example, in Patent Document 1 below, a metal layer made of, for example, Sn is formed on a base material, an oxide layer formed on the surface is removed, and then the metal surface of the metal is subjected to hydroxylation treatment to form SnO ₂ . A method of manufacturing an electrical contact material for a connector that forms such an oxide layer is disclosed.

JP 2012-237055 A

However, in the prior art as described above, although no precious metal plating layer is used, the number of steps such as formation of the metal layer, surface treatment of the metal layer, and further hydroxylation treatment is increased, thereby sufficiently reducing the cost. I can't.
Further, when such a metal layer is not formed, when the terminal is downsized, the contact load is reduced, so that the oxide film on the Sn surface is not destroyed when the connector is fitted, and the contact resistance is reduced. There was a problem that the rise could not be suppressed sufficiently.
Further, in the conventional technology as described above, when the number of terminals included in the connector is increased, the insertion force when inserting one terminal into the other terminal is increased, and the workability of connector fitting is reduced. It was.

  Therefore, the object of the present invention is low cost, prevents deterioration of product reliability due to oxidation of the base material, and keeps the true contact surface large even for a small and low contact load electrical contact. An object of the present invention is to provide an electrical element and a connector that can solve the problem of an increase in contact resistance and that does not deteriorate the workability at the time of connector fitting even when the number of terminals increases.

  In order to achieve the above-described object, an electrical element and a connector according to the present invention are characterized by the following (1) to (5).

(1) An electrical element that is electrically connected to the counterpart terminal by being inserted into and brought into contact with the counterpart terminal,
An oxide thin film doped with an element is provided at least in a region in contact with the counterpart terminal on the substrate,
The oxide thin film is provided on the substrate in a state where the surface of the substrate is smooth,
An electric element, wherein the element is an element contributing to the development of conductivity.
(2) The element contributing to the development of conductivity is at least one selected from the group consisting of F, In, Ga, Tl, As, Sb, and Bi, as described in (1) above Electrical element.
(3) The electric element according to (2), wherein the element contributing to the development of conductivity includes at least F.
(4) The electrical element according to any one of (1) to (3), wherein the electrical element is a terminal inserted into the counterpart terminal.
(5) The connector provided with the said terminal as described in said (4).

  Since the electrical element of the present invention is provided with a specific oxide thin film on a base material, it is low in cost and prevents deterioration of product reliability due to oxidation of the base material, and is small and has a low contact load. Even with this electrical element, it is possible to provide an electrical element and a connector that can solve the problem of increased contact resistance.

It is a schematic diagram for demonstrating the electric element provided with the oxide thin film. It is sectional drawing of the terminal which concerns on embodiment of this invention. FIG. 3 is a partially enlarged view of FIG. 2.

Hereinafter, the present invention will be described in more detail.
FIG. 1 is a schematic view showing a cross section of an electric element provided with an oxide thin film.
In FIG. 1, the electric element 1 is formed by providing an oxide thin film 16 doped with an element on a base 12.
The material of the base material 12 is not particularly limited and can be appropriately selected depending on the application. However, as a connector terminal, a Cu alloy such as Cu or brass can be generally used. Apart from this, Al, Fe or alloys thereof can also be used. The thickness of the base material 12 can be appropriately determined according to the application, and the shape of the base material 12 can be a rectangular shape, a cylindrical shape, or other irregular shapes. In the present embodiment, the male terminal 32 and the female terminal 34 are formed using the base material 12.

Examples of the material of the oxide constituting the oxide thin film 16 include SnO, SnO ₂ , NiO, Ni ₂ O ₃ , ZnO, CuO ₂ , CuAlO ₂ , In ₂ O ₃ , or a mixture thereof. From the viewpoint of inter alia improving the effect of the present invention, the oxide is preferably a SnO and / or SnO _2.

The element doped in the oxide thin film 16 is preferably an element that contributes to the development of conductivity, and includes, for example, at least one selected from the group consisting of F, In, Ga, Tl, As, Sb, and Bi. Among these, from the viewpoint of the effects of the present invention and from the viewpoint of excellent conductivity and wear resistance, F is preferable, and the oxide thin film 16 is particularly preferably fluorine-doped tin oxide (FTO).
The thickness of the oxide thin film 16 is, for example, 10 nm to 1 μm.

  Note that a Ni plating layer may be provided on the base material 12 in order to prevent, for example, Cu or Cu alloy contained in the base material 12 from diffusing on the oxide thin film 16 as necessary. For the Ni plating layer, Ni alloy such as Fe—Ni alloy or Sn—Ni alloy can be used in addition to Ni. The thickness of the Ni plating layer is determined as appropriate as long as the object can be achieved.

Next, a method for manufacturing a terminal provided with an oxide thin film will be described.
First, the base material 12 is prepared, and the surface of a region where an FTO thin film 36 described later as the oxide thin film 16 is provided is polished. Polishing is performed by a known method for smoothing the surface, such as mechanical polishing or chemical polishing. Moreover, a Ni plating layer is formed on the surface of the substrate 12 as necessary. The Ni plating layer can be formed by a method that keeps the surface smooth, such as a known plating method. For example, the electrolytic plating method is a method that is conventionally performed, and is preferable because the apparatus configuration is simple and the control of the layer thickness is relatively easy.

  Next, an oxide thin film 16 doped with an element is provided on the substrate 12. The oxide thin film 16 can be provided by, for example, a spray pyrolysis (SPD) method. As is well known in the SPD method, the substrate 12 is heated to a film formation temperature, and a solution as a film raw material is sprayed toward the substrate 12 using a spraying means such as an atomizer. In this method, a crystal is formed by the evaporation of the solvent in the droplet attached to the substrate surface and the hydrolysis reaction and thermal oxidation reaction following the thermal decomposition of the solute, and as the reaction proceeds, a droplet is formed on the crystal. Is a method of forming a thin film by causing crystal growth to proceed between the solute and the lower crystal as the solvent evaporates in the droplet. By employing the SPD method, the oxide thin film 16 can be formed in a pinpoint and / or arbitrary shape. The oxide thin film 16 can be formed by employing a known method other than the SPD method.

The oxide thin film 16 formed in this manner has conductivity (for example, a specific resistance value of 1 × 10 ⁷ Ω · cm or less), exhibits the effects of the present invention, and wear resistance. Excellent in corrosion resistance, corrosion resistance, heat resistance, etc.

  FIG. 2 is a cross-sectional view of the terminal according to the embodiment of the present invention. FIG. 3 is a partially enlarged view of the terminal shown in FIG. As shown in FIG. 2, the male terminal 32 and the female terminal 34 function as connector electrical contacts. The male terminal 32 and the female terminal 34 are housed and held in terminal housing chambers of male connectors and female connectors (not shown), respectively. Note that FIG. 2 shows the vicinity of a place where the male terminal 32 and the female terminal 34 are in contact with each other, but the male terminal 32 and the female terminal 34 may have a known shape. The female terminal 34 has a spring portion 35, and the male terminal 32 is electrically connected to the female terminal 34 by contacting the spring portion 35 of the female terminal 34.

  As shown in the partially enlarged view of FIG. 3, in the fitting portion between the male terminal 32 and the female terminal 34, the male terminal 32 has the FTO thin film 36 formed on the base material 12 whose surface is smoothed by polishing, It is in contact with the female terminal 34 side.

  As the substrate 12, a Cu alloy made of brass is used. And the FTO thin film 36 was provided by SPD method on the base material 12 with which the surface was smooth | blunted, and the male terminal 32 was manufactured. In addition, the material of the base material of the male terminal 32 and the female terminal 34 may differ from each other. In this embodiment, the FTO thin film 36 is formed only on the male terminal 32, but the FTO thin film 36 may be formed on the female terminal 34.

  Compared with the case where the FTO thin film 36 is not provided, the male terminal 32 of the present embodiment has a reduced coefficient of friction between the male terminal 32 and the female terminal 34 when fitting the male connector and the female connector, and It can suppress that the metal oxide film which comprises the base material 12 is formed in the surface. Therefore, even if the number of terminals included in the connector is increased, it is possible to prevent the insertion force from being increased when the connectors are fitted to each other and the workability of the connector fitting to be lowered. Further, when the FTO thin film 36 is not provided, the contact load is reduced when the male terminal 32 and the female terminal 34 are downsized, so that the oxide film formed on the surface of one terminal is destroyed by the other terminal. However, if the FTO thin film 36 is formed, it is not necessary to destroy such an oxide film, so that an increase in contact resistance can be prevented.

Here, the features of the embodiments of the electrical element and the connector according to the present invention described above are briefly summarized and listed in the following [1] to [5], respectively.
[1] An electrical element (male terminal 32) that is electrically connected to the counterpart terminal (female terminal 34) by being inserted into and brought into contact with the counterpart terminal (female terminal 34),
On the base material (12), an oxide thin film doped with an element is provided at least in a region in contact with the counterpart terminal (female terminal 34),
The oxide thin film is provided on the base material (12) in a state where the surface of the base material (12) is smooth,
The terminal (male terminal 32), wherein the element is an element that contributes to conductivity.
[2] The element according to [1], wherein the element contributing to the development of conductivity is at least one selected from the group consisting of F, In, Ga, Tl, As, Sb, and Bi. Electrical element.
[3] The electric element (male terminal 32) according to the above [2], wherein the element contributing to the development of conductivity includes at least F.
[4] The electrical element according to any one of [1] to [3], wherein the electrical element is a terminal (male terminal 32) inserted into the counterpart terminal.
[5] A connector comprising the terminal (male terminal 32) according to [4].

DESCRIPTION OF SYMBOLS 1 Electric element 12 Base material 16 Oxide thin film 32 Male terminal (terminal)
34 Female terminal (mating terminal)
35 Spring 36 FTO thin film

Claims (5)

An electrical element that is electrically connected to the counterpart terminal by being inserted into and contacted with the counterpart terminal,
An oxide thin film doped with an element is provided at least in a region in contact with the counterpart terminal on the substrate,
The oxide thin film is provided on the substrate in a state where the surface of the substrate is smooth,
An electric element, wherein the element is an element contributing to the development of conductivity.   The electric element according to claim 1, wherein the element contributing to the expression of conductivity is at least one selected from the group consisting of F, In, Ga, Tl, As, Sb, and Bi.   The electric element according to claim 2, wherein the element contributing to the development of conductivity includes at least F.   The electric element according to any one of claims 1 to 3, wherein the electric element is a terminal inserted into the counterpart terminal. The connector provided with the said terminal of Claim 4.

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