JP2010037629A - Conducting material for terminal and connector, and fitting-type connecting terminal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conducting material for a terminal and a connector, which is suitable for a multipolarized miniature terminal, can inhibit electric contact resistance from rising due to fine slide abrasion, and gives high electric connection reliability to the terminal, and to provide a fitting-type connection terminal. <P>SOLUTION: The conducting material for the terminal and the connector includes: a substrate 2 having electroconductivity; and an Sn-plated layer 5, which is formed of Sn or an Sn alloy and formed on the substrate 2. The thickness of the Sn-plated layer 5 is controlled in a range of 0.1 to 15.0 μm in a stacked direction. An Ag-Sn alloy layer 6 made of aggregated Ag-Sn particulates is formed on the surface of the Sn-plated layer 5, and the average thickness of the Ag-Sn alloy layer 6 is set in a range of 0.002 to 1.0 μm. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a connection terminal and a conductive material for a connector that are suitable as a material for a connector and a connector that are installed in a place subject to vibration such as an automobile or an electronic device, and a fitting-type connection terminal using the conductive material for the terminal / connector. It is about.

Conventionally, as a terminal / connector conductive material for forming a connection terminal or a connector, a Sn plating material in which Sn metal is coated on the surface of a copper alloy or steel material which is a conductive base material is used. Sn-plated materials have excellent solder wettability and electrical contact characteristics (contact characteristics), and are widely used as conductive materials for terminals and connectors because of their low cost.
In recent years, automobiles have become increasingly electronic, and integrated circuits such as LSIs and ICs have been used in many cases, and signal currents flowing through terminals and connectors have also been lowered. In connection with this, the stability of the electrical contact resistance of a connection terminal and a connector is requested | required.

  Connection terminals and connectors used in automobiles are formed on the surface of the connection terminals and connectors at contact points by moving (sliding) in a short distance (20 to 100 μm) between the terminals due to vibration associated with traveling, etc. So-called fine sliding wear (fretting corrosion) that wears the plated layer occurs. When this fine sliding wear occurs, the surfaces of the connection terminal and the connector are scraped to generate wear powder, which is oxidized in the atmosphere. The oxidized wear powder enters between the contacts, resulting in poor contact and further acting as an abrasive to promote contact wear. Thereby, the electrical contact resistance of a terminal and a connector increases, and the problem that the electrical connection reliability of a product will fall is known.

  In particular, the connection terminals and connectors formed using the above-mentioned general Sn plating material are relatively soft in Sn metal. Therefore, when used for electrical connection in an environment subject to vibrations such as automobiles, fine sliding wear occurs. There is a problem that the electrical connection is deteriorated due to the oxidation of the Sn plating layer itself at the contact portion due to the influence, or the plating layer is quickly consumed and the base material is oxidized.

Therefore, various measures have been proposed in the past to improve the fine sliding wear of the connection terminals and connectors. For example, in Patent Document 1, the shape of the connection terminal and the connector is changed to increase the fitting force between the male terminal and the female terminal, thereby suppressing vibration and reducing the gap between the terminals to increase the electrical contact resistance. A method of suppressing this is disclosed. In other words, the oxide powder formed by friction does not enter between the contacts.
Patent Document 2 proposes to use, as a connector material, a material whose surface is not oxidized by fine sliding wear, for example, a precious metal plating treatment material such as Ag, Au, and Pd.
JP 2001-297820 A JP-A 62-70596

  By the way, recently, with the advancement of electrical equipment in automobiles, multifunctional electronic control devices are required, and the number of terminals (number of pins) of connectors is increasing. Is required. For this reason, reduction of the load (inter-terminal fitting force) of a connector contact part is calculated | required. However, if the load on the connector contact portion is reduced, it becomes more susceptible to vibration and the oxide powder generated by friction is likely to enter between the contact points of the terminal, causing problems such as connector contact failure and increased electrical contact resistance. There was a problem that it was easy to do. Further, when the load is reduced, the surface state (oxide film and surface conductivity) of the terminal material has a great influence on the electrical connection state of the contact portion. For this reason, as described in Patent Document 1, it has become impossible to sufficiently suppress the fine sliding wear only by devising the connector shape.

  In addition, when a noble metal plating material is used as described in Patent Document 2, the material cost is significantly increased. Furthermore, because the solder wettability is poor, it is necessary to significantly change the part assembly method from the conventional Sn plating material, and the equipment and means of the existing mounting line will be changed. Met.

Furthermore, recently, with the miniaturization and narrowing of the connector, whisker resistance to the lead-free Sn plating material is required, and the electrical contact resistance in a high temperature environment against the connector terminal in the engine room of an automobile is required. The demand for stability, that is, heat resistance, is increasing. In other words, in order to improve the electrical connection reliability of products, requirements for terminals, connectors, and contact materials used in automobiles and electrical equipment are becoming stricter year by year. The characteristics such as are demanded more severely.
Therefore, in order to improve the electrical connection reliability of products, the provision of Sn-plated terminal / connector materials that are less susceptible to surface oxidation due to fine sliding wear or that can suppress the deterioration of electrical contact resistance due to fine sliding wear Is strongly desired.

  The present invention has been made in view of the above problems, and is suitable for a multi-terminal small terminal, can suppress an increase in electrical contact resistance due to fine sliding wear, and has high electrical connection reliability. An object is to provide a conductive material and a fitting-type connection terminal.

  In order to solve this problem, the present inventors have conducted intensive research. As a result, a thin Ag layer is formed on the Sn plating layer, and the Ag is maintained at a temperature much lower than the temperature at which Sn melts. And Sn are diffused and reacted to form an Ag-Sn alloy layer in which Ag-Sn fine particles are aggregated on the surface of the Sn plating layer, and the thicknesses of the Ag-Sn alloy layer and the Sn plating layer are optimized. It was found that the increase in contact resistance due to fine sliding wear can be suppressed. In addition, in the fitting type connection terminal, it was found that the life of the fitting type connection terminal can be extended by combining the plating structure of the female terminal and the plating structure of the male terminal.

  The present invention has been made on the basis of such knowledge, and the terminal / connector conductive material according to the present invention includes a conductive base material and Sn or Sn alloy formed on the base material. A conductive material for a terminal / connector comprising a Sn plating layer, wherein the Sn plating layer has a stacking direction thickness in a range of 0.1 to 15.0 μm, and the surface of the Sn plating layer Is formed with an Ag—Sn alloy layer in which Ag—Sn fine particles are aggregated, and the average thickness of the Ag—Sn alloy layer is set within a range of 0.002 to 1.0 μm. It is said.

In the conductive material for terminal / connector having this configuration, an Ag—Sn alloy layer in which Ag—Sn particles are aggregated is formed on the surface layer portion of the Sn plating layer. Here, since the Ag-Sn alloy layer formed by aggregation of Ag-Sn particles has high corrosion resistance, it is possible to suppress oxidation of the surface of the Sn plating layer in the use environment.
Further, the Ag-Sn particles, mainly because consisting Ag 3 _Sn intermetallic compound, the surface is hard for the terminal connector conductive material, it is possible to improve the abrasion resistance, suppress the generation of abrasion powder be able to.

Furthermore, even when wear powder generated by fine sliding is oxidized and dispersed on the surface, conductive Ag—Sn particles (Ag ₃ Sn intermetallic compound) are present on the surface of the conductive material for terminals and connectors. Therefore, electrical contact can be made with this Ag ₃ Sn intermetallic compound, and an increase in contact resistance can be suppressed.
More specifically, the connection terminals are first electrically connected by the surface Sn plating layers. If fine sliding continues to act on this, Sn of the Sn plating layer is scraped to become wear powder, which is further oxidized and dispersed in the surface layer, and the electrical contact resistance increases. Here, in the present invention, since the Ag—Sn alloy layer is formed on the surface of the Sn plating layer, Ag—Sn particles having conductivity are dispersed on the surface of the Sn plating layer together with oxidized Sn. Thus, an increase in electrical contact resistance is suppressed.

Furthermore, since the average thickness of the Ag—Sn alloy layer is set within a range of 0.002 to 1.0 μm, an increase in contact resistance can be suppressed by reliably making the Ag ₃ Sn intermetallic compound present. At the same time, there is no presence of pure Ag on the surface, and an increase in electrical contact resistance due to the sulfur discoloration of Ag can be suppressed.

Moreover, since the thickness of the Sn plating layer in the stacking direction is 0.1 μm or more, solder wettability and formation of an Ag—Sn alloy layer can be ensured. Further, since the thickness of the Sn plating layer in the stacking direction is 15.0 μm or less, the workability of the conductive material for the terminal / connector can be ensured. Moreover, the insertion / extraction property at the time of forming a fitting type connection terminal is securable.
In addition, as the base material, at least a material having a conductive surface is used. For example, a conductive material made of a metal such as Cu and Cu alloy or Fe and Fe alloy, or a composite material in which the surface of a non-conductive material is coated with a conductive material can be used. Of these, Cu and Cu alloy materials having high conductivity and good mechanical properties are preferred.

Here, a Cu layer made of Cu or a Cu alloy may be formed between the base material and the Sn plating layer.
In this case, the chemical state of the substrate surface is made uniform by the Cu layer, and the Sn plating layer is formed thereon, thereby preventing the diffusion of the elements of the substrate to the Sn plating layer and the uniformity of the Sn plating layer. Can be improved. The method for forming this Cu layer is not particularly limited, and electroplating, electroless plating, or displacement plating may be used.

Furthermore, a diffusion preventing layer for preventing diffusion of elements in the substrate may be formed on the substrate.
In this case, the diffusion prevention layer can prevent diffusion alloying between the element in the base material and Sn in a high temperature environment, and the heat resistance of the conductive material for terminals and connectors and the bonding strength between the Sn plating layer and the base material. Can be improved. In addition, the element which makes a diffusion prevention layer should just be a thing which does not react easily with the element in the said base material. Here, for example, in the case of a base material made of Cu or Cu alloy, Ni, Cr, Mo, W, Al, Ti, Zr, V, Ta, Nb or the like or an alloy thereof can be applied as the diffusion preventing layer. it can.

The fitting type connection terminal according to the present invention is a fitting type connection terminal having a male terminal and a female terminal which are fitted to each other, and at least one of the male terminal and the female terminal is a conductive material for the terminal / connector described above. It is composed of materials.
According to the fitting type connection terminal having this configuration, even if a slight sliding action occurs, an increase in contact resistance can be suppressed by the conductive Ag ₃ Sn intermetallic compound, and the electrical connection reliability is greatly improved. be able to.

Further, both the male terminal and the female terminal may be made of the above-described terminal / connector conductive material, and the Ag—Sn alloy layer may be arranged so as to face each other. .
In this case, since the Ag—Sn alloy layers are disposed so as to face each other, an increase in electrical contact resistance due to fine sliding wear can be reliably suppressed. In addition, one of them does not wear out early, and the life of the fitting type connection terminal can be extended. Furthermore, since it is excellent in heat resistance, it can be used even in a high temperature environment such as an engine room of an automobile. In addition, the Sn conductive material covering the Ag—Sn alloy layer of the present invention has excellent heat resistance and Sn whisker resistance, so it can be applied even in a high temperature environment such as an engine room of an automobile, and in particular, a fitting force between connection terminals. The occurrence of Sn whisker due to the above can be suppressed, and the reliability of the product can be improved.

Moreover, either the said male terminal or the said female terminal is comprised with the above-mentioned conductive material for terminals and connectors, and the other of the said male terminal and the said female terminal is comprised with Sn plating electrically-conductive material. May be adopted.
In this case, one terminal has an Ag—Sn alloy layer and the surface is relatively hard, the other terminal is an Sn-plated conductive material, and the surface is softer than the one terminal. In this way, vibration can be absorbed by combining a hard plating layer (Ag—Sn alloy layer) and a soft plating layer (Sn plating layer), and the micro-sliding wear resistance can be greatly improved. Can do.

Furthermore, the convex part which protruded toward the said male terminal side is formed in the said female terminal, the said female terminal is comprised with the above-mentioned conductive material for terminals and connectors, and the said male terminal is comprised with Sn plating electrically-conductive material. You may employ | adopt the structure which is.
In this case, by using a relatively hard Ag-Sn alloy layer for the female terminal on which the convex portion is formed, it is possible to suppress the consumption of the plating layer of the convex portion that is most likely to wear and deteriorate, The life of the entire terminal can be extended without unilaterally premature wear.

  According to the present invention, a conductive material for a terminal / connector and a fitting-type connection terminal that are suitable for a multi-terminal small terminal, can suppress an increase in electrical contact resistance due to fine sliding wear, and have high electrical connection reliability are provided. It becomes possible to do.

Hereinafter, a terminal / connector conductive material 1 according to a first embodiment of the present invention will be described with reference to the accompanying drawings.
As shown in FIG. 1, the terminal / connector conductive material 1 according to the present embodiment is formed on a substrate 2, a Ni plating layer 3 formed on the surface of the substrate 2, and a surface of the Ni plating layer 3. Cu layer 4 formed, Sn plating layer 5 formed on the surface of Cu layer 4, and Ag—Sn alloy layer 6 formed on the surface of Sn plating layer 5.

The base material 2 is made of a conductive metal. In the present embodiment, the base material 2 is basically made of various copper alloys, but iron-based alloys are also used.
The Ni plating layer 3 is an element diffusion prevention layer of the base material 2 and is made of Ni or Ni alloy, and is formed on the surface of the base material 2 by electroplating. The thickness of the Ni plating layer 3 is set within a range of 0.01 to 1.0 μm.

  The Cu layer 4 is a diffusion preventing layer for alloying Ni and Sn, and is made of Cu or Cu alloy, and is formed on the surface of the Ni plating layer 3 by electroplating. The Cu layer 4 has a function of preventing Ni in the Ni plating layer 3 from diffusing into the Sn plating layer 5. Specifically, the thickness of the Cu layer 4 is set within a range of 0.1 to 1.0 μm.

  The Sn plating layer 5 is made of Sn or an Sn alloy and is formed by electrolytic plating or electroless plating. The thickness of the Sn plating layer 5 should basically satisfy the solder wettability, and is set in the range of 0.1 to 15.0 μm depending on the application. The Sn plating layer 5 is subjected to a reflow process (melting process) which will be described later, and the stress inside the plating layer 5 is released.

The Ag—Sn alloy layer 6 is formed by aggregation of Ag—Sn particles on the surface layer portion of the Sn plating layer 5 in a cross section along the stacking direction of the base material 2 and the Sn plating layer 5. Incidentally, Ag-Sn particles is _Ag 3 Sn intermetallic compound having conductivity. The average thickness of the Ag—Sn alloy layer 6 is set in the range of 0.002 to 1.0 μm. In addition, since the thickness of the Ag—Sn alloy layer 6 is 0.002 to 1.0 μm, the Ag—Sn alloy layer 6 is uniformly dispersed in the Sn plating layer as fine particles or an aggregate of the fine particles or continuously. It is in a dense state.

Below, the manufacturing method of this Sn plating electrically-conductive material 1 is demonstrated with reference to the flowchart shown in FIG.
First, the Ni plating layer 3 is formed on the surface of the substrate 2 by electroplating (Ni plating layer forming step S1).
Next, a Cu layer 4 is formed on the surface of the Ni plating layer 3 by electroplating (Cu layer forming step S2).
Then, an Sn plating layer 5 is formed on the Cu layer 4 by electrolytic plating or electroless plating (Sn plating layer forming step S3).
After the Sn plating layer 5 is thus formed by plating, a reflow process is performed in which the Sn is melted by heating to a melting point of the Sn metal or higher (reflow process step S4). At this point, part or all of the Cu layer 4 becomes a Cu—Sn alloy.

  Next, as shown in FIG. 2, the thickness of 0.001 is applied to the surface of the Sn plating layer 5 subjected to the reflow treatment by a plating method selected from electroplating, electroless plating, displacement plating, and vapor deposition. An Ag layer 7 made of ~ 0.5 μm Ag or an Ag alloy is formed (Ag layer forming step S5).

And in the state which formed Ag layer 7 on the surface of Sn plating layer 5, it immersed in the warm water bath adjusted to 10-100 degreeC, and hold | maintained for 2 seconds or more, Ag of Ag layer 7 and Sn plating layer 5 It reacts with Sn to produce Ag—Sn particles (Ag ₃ Sn intermetallic compound) to form an Ag—Sn alloy layer 6 having a thickness of 0.002 to 1.0 μm (Ag—Sn alloy layer forming step S6). ).

  As described above, the terminal / connector conductive material 1 according to this embodiment is manufactured. As shown in FIG. 4, the terminal / connector conductive material 1 is used after being processed into a fitting connection terminal 8 composed of a male terminal 8A and a female terminal 8B that are fitted together.

According to the terminal / connector conductive material 1 of this embodiment, the Ag—Sn alloy layer 6 in which Ag—Sn particles (Ag ₃ Sn intermetallic compound) are aggregated is formed on the surface layer portion of the Sn plating layer 5. Since the Ag—Sn alloy layer 6 has high corrosion resistance, surface oxidation of the Sn plating layer 5 can be suppressed in the use environment. Moreover, since the Ag—Sn alloy layer 6 is composed of Ag—Sn particles (Ag ₃ Sn intermetallic compound), the surface of the conductive material 1 for terminals and connectors is hardened, and wear resistance is improved. And generation of wear powder can be suppressed.

Furthermore, even when wear powder generated by fine sliding is oxidized and dispersed on the surface, conductive Ag-Sn particles (Ag ₃ Sn intermetallic compound) are present on the surface of the conductive material 1 for terminals and connectors. In addition, electrical contact can be made with this Ag ₃ Sn intermetallic compound, and an increase in contact resistance can be suppressed. .

In addition, since the average thickness of the Ag—Sn alloy layer 6 is set in the range of 0.002 to 1.0 μm, the Ag ₃ Sn intermetallic compound can be surely present to suppress an increase in contact resistance. At the same time, there is no presence of pure Ag on the surface, and an increase in electrical contact resistance due to the sulfur discoloration of Ag can be suppressed.
Furthermore, when used for a long time in a high temperature environment, even if the Sn plating layer 5 is completely Sn—Cu alloyed, Ag—Sn particles that are difficult to oxidize are aggregated on the Sn plating layer 5 and are always on the surface of the plating layer. In spite of the oxidation of the Sn—Cu alloy, the electrical connection between the terminals and contacts can be maintained as an electrical path.
In particular, the Ag—Sn particles on the surface give tensile stress to the Sn plating layer 5 below, offsetting internal stress caused by Sn—Cu alloying and compressive stress such as external stress due to fitting between terminals. Since it is possible to suppress the occurrence of Sn whiskers, which is the biggest problem related to the plating terminal material, it is possible to improve the overall reliability of the product.

  Furthermore, since the thickness in the stacking direction of the Sn plating layer 5 is 0.1 μm or more, solder wettability and formation of the Ag—Sn alloy layer 6 can be ensured. Moreover, since the thickness of the Sn plating layer 5 in the stacking direction is 15.0 μm or less, the workability of the conductive material 1 for terminals and connectors can be ensured. Moreover, the insertion / extraction property at the time of forming a fitting type connection terminal is securable.

Further, since the Ni plating layer 3 made of Ni or Ni alloy is formed between the base material 2 and the Sn plating layer 5 as an element diffusion prevention layer of the base material 2, It is possible to prevent an element such as Cu of the material 2 from diffusing into the Sn plating layer 5, to improve the heat resistance of the Sn plating conductive material 1, and to prevent thermal peeling even when used in a high temperature environment. Can do.
Further, since the Cu layer 4 is formed as the Ni diffusion preventing layer on the Ni plating layer 3, the Cu layer 4 can prevent Ni from diffusing into the Sn plating layer 5. Degradation of solder wettability can be prevented.

  In addition, the terminal / connector conductive material 1 according to the present embodiment includes a Ni plating layer forming step S1 for forming a Ni plating layer 3 made of Ni or a Ni alloy on the surface of the base material 2, and a Cu plating on the Ni plating layer. Alternatively, the Cu layer forming step S2 for forming the Cu layer 4 made of Cu alloy, the Sn plating layer forming step S3 for forming the Sn plating layer 5 made of Sn or Sn alloy on the Cu layer 4, and the Sn plating layer 5 Reflow treatment step S4 for performing heat treatment, Ag layer formation step S5 for forming an Ag layer 7 made of Ag or an Ag alloy on the Sn plating layer 5 formed by this Sn plating layer formation step, and 10 ° C. or higher It is produced by Ag-Sn alloy layer forming step S6, which is held at a temperature lower than 100 ° C. for 2 seconds or longer, and Ag of Sn layer 7 is reacted with Sn of Sn plating layer 5 to form Ag—Sn alloy layer 6. .

Here, since the temperature condition in Ag-Sn alloy layer formation process S6 shall be 10 degreeC or more, reaction of Ag and Sn can be accelerated | stimulated. Further, since the temperature conditions in the Ag-Sn alloy layer forming step S6, is less than 100 ° C., can be suppressed more than necessary reaction between Ag and Sn, Ag-Sn particles _(Ag 3 Sn intermetallic compound), It is possible to prevent the substrate 2 and the Sn plating layer 5 from being dispersed throughout the Sn plating layer 5 in a cross section along the stacking direction, and Ag-Sn particles can be aggregated on the surface layer of the Sn plating layer 5. It becomes. Moreover, the Ag-Sn alloy layer formation process S6 can be performed by being immersed in a water bath system liquid, and the conductive material 1 for terminals and connectors can be manufactured at low cost without using a high temperature heating furnace etc.

  In addition, since the Ag layer forming step S5 is to form the Ag layer 7 having a thickness of 0.001 to 1.0 μm by a plating method selected from an electroplating method, an electroless plating method, and an evaporation method. Ag—Sn particles can be generated by promoting the reaction between Sn and Sn, and the Ag—Sn alloy layer 6 can be reliably formed, and all of the Ag in the Ag layer 7 can be reacted, and the Sn plating layer It is possible to prevent the Ag layer 7 from remaining on the surface of 5. Thus, by making all Ag of the Ag layer 7 react to leave no pure Ag on the surface of the Sn plating layer 5, it is possible to prevent an increase in electrical contact resistance and electrical contact resistance due to discoloration of the Ag surface.

  In addition, after the Sn plating layer forming step S3, there is a reflow processing step S4 in which the Sn plating layer 5 is subjected to a heat treatment. Therefore, internal stress generated in the Sn plating layer 5 in the Sn plating layer forming step S3 is reflowed. It can be released by processing, and the spontaneous generation of Sn whiskers due to this internal stress can be prevented.

Next, a terminal / connector conductive material 11 according to a second embodiment of the present invention will be described with reference to FIG.
In the terminal / connector conductive material 11 according to the present embodiment, the base 12 is processed according to the shape of the component, and the Cu layer 14 formed on the surface of the base 12 and the surface of the Cu layer 14 The formed Sn plating layer 15 and an Ag—Sn alloy layer 16 formed on the surface of the Sn plating layer 15 are provided.

The substrate 12 is basically composed of various copper alloys as in the first embodiment, but iron-based alloys are also used.
The Cu layer 14 is made of Cu or a Cu alloy formed on the surface of the substrate 12 by an electroplating method or an electroless plating method. The thickness of the Cu layer 14 is set in the range of 0.01 to 1.0 μm.

  The Sn plating layer 15 is made of Sn or an Sn alloy, and is formed by electrolytic plating or electroless plating. The thickness of the Sn plating layer 15 should basically satisfy the solder wettability, and is set in the range of 0.1 to 15.0 μm depending on the application. In the second embodiment, assuming a practical case, the Sn plating layer 15 is locally formed only on a necessary portion of the base material 12, and the internal stress of the Sn plating layer 15 is released. The intended reflow treatment up to the melting temperature of Sn was not performed.

  The Ag—Sn alloy layer 16 is formed by aggregation of Ag—Sn particles on the surface layer portion of the Sn plating layer 15 in a cross section along the stacking direction of the base material 12 and the Sn plating layer 15. The average thickness of the Ag—Sn alloy layer 16 is set within a range of 0.002 to 1.0 μm.

Below, the manufacturing method of this conductive material 11 for terminals and connectors is demonstrated with reference to the flowchart shown in FIG.
First, the base material 12 is processed according to the shape of the part (base material processing step S′0).
Next, masking is performed on the portion of the substrate 12 where the Sn plating layer 15 is not formed (masking step S′1).

Next, a Cu layer 14 is formed on the exposed surface of the substrate 12 as an anti-diffusion layer of the substrate 12 by electroplating or electroless plating (Cu layer forming step S′2).
An Sn plating layer 15 is formed on the Cu layer 14 by electroplating or electroless plating (Sn plating layer forming step S′3).

Next, an Ag layer made of Ag or an Ag alloy having a thickness of 0.001 to 0.5 μm is formed on the surface of the Sn plating layer 15 by a plating method selected from electroplating, electroless plating, displacement plating, and vapor deposition. (Ag layer forming step S′5).
Then, in a state where the Ag layer is formed on the surface of the Sn plating layer 15, it is immersed in a warm water bath adjusted to 10 or more and less than 100 ° C. and held for 2 seconds or more. Ag of the Ag layer and Sn of the Sn plating layer 15 To produce Ag—Sn particles (Ag ₃ Sn intermetallic compound) to form an Ag—Sn alloy layer 16 (Ag—Sn alloy layer forming step S ′ 6).

  According to the terminal / connector conductive material 11 that is the second embodiment having such a configuration, the Ag—Sn alloy layer 16 allows the fine sliding wear during the fine sliding wear, as in the first embodiment described above. An increase in electrical contact resistance can be suppressed.

The conductive material for terminal / connector which is an embodiment of the present invention has been described above, but the present invention is not limited to this description and can be appropriately changed without departing from the technical idea of the present invention.
Although the Ni base, the Cu base, and the Sn plating layer are sequentially formed on the surface of the base material and the reflow process is performed (first embodiment), the present invention is not limited to this, and the Cu and Sn plating layers are not limited thereto. Alternatively, it may be reflowed by direct Sn plating on the surface of the substrate. Moreover, although it demonstrated by what formed Cu base layer in 2nd Embodiment, it is not limited to this, You may form Sn plating layer directly on the surface of a base material.

  Moreover, although demonstrated as what comprised the base material with the metal electrically-conductive material, it is not limited to this, You may comprise with what coated the material which has electroconductivity on the surface of a nonmetallic material. Specifically, Cu-Ni-Si based copper alloy, Cu-Mg-P based copper alloy, Cu-Fe-P based copper alloy, Cu-Zn based copper alloy, Cu-Cr-Sn-Zn based copper alloy, Examples thereof include metal conductive materials such as SUS and Fe-42Ni alloys, organic film materials and semiconductors, and nonmetallic materials in which the surfaces of glass and ceramic materials are coated with a conductive metal film such as Cu.

  Moreover, in the Ag-Sn alloy layer formation process, although it demonstrated as what was immersed in the warm water bath adjusted to the temperature of 10 degreeC or more and less than 100 degreeC for 2 seconds or more, it is not limited to this, Other than a warm water bath By means, Ag—Sn particles may be generated by reacting Ag and Sn while maintaining an Ag layer on the surface of the Sn plating layer for 2 seconds or more at a temperature of 10 ° C. or more and less than 100 ° C.

Furthermore, although it demonstrated as what forms a Sn plating layer by electroplating or electroless plating, it is not limited to this, You may form a Sn plating layer by HotDip method. Moreover, although it demonstrated as what performed the reflow process after forming Sn plating layer, as shown in FIG. 6, you may form an Ag layer, without performing a reflow process.
In the second embodiment, the reflow process is not performed. However, the reflow process may be performed after forming the Sn plating layer by processing into the shape of the component. Moreover, although demonstrated as what does not heat-process the electrically conductive material 11 for terminals and connectors, according to a use, you may heat-process at the temperature (for example, 120-200 degreeC) which Sn does not fuse | melt.

Moreover, in the schematic diagram of this embodiment, although demonstrated by what formed the Sn plating layer and the Ag-Sn alloy layer in one surface of a base material, it is not limited to this, Sn is formed in the whole surface of a base material. A plating layer and an Ag—Sn alloy layer may be formed.
Furthermore, in the schematic diagram of the present embodiment, the Sn plating layer and the Ag—Sn alloy layer are formed on the entire surface of the base material, but the present invention is not limited to this, and the Sn plating layer and the Ag—Sn alloy are used. The layer may be formed locally near the contact of the terminal.

Below, the result of the fine sliding wear test performed in order to verify the effectiveness of this invention is demonstrated.
A precision sliding tester (manufactured by Yamazaki Seiki Laboratories: CRS-G2050-MTS type) was adopted as the evaluation apparatus for fine sliding wear. The measurement conditions were room temperature, amplitude of 50 μm, sliding frequency of 1 Hz, load of 100 g (1 N), and the value of electrical contact resistance according to the variation of the number of sliding times (cycle number). (Here, in order to increase the sensitivity of evaluation, low load (usually 1 to 20 N), small amplitude (usually 20 to 200 μm) and high sliding frequency (usually 0.013 to 1 Hz) based on the results of preliminary tests) We selected and evaluated the conditions.)
Electrical contact resistance is measured in accordance with JIS-C-5402, measured by the 4-terminal method (measurement current: 10 mA, maximum open potential 20 mV), data is sent to a computer at a measurement interval of 2 times, sampling rate of 1 / measurement. Collected.

  FIG. 7 schematically shows the contact configuration and the shape of the test piece of the fine sliding wear tester. As shown in FIG. 7, the fine sliding wear tester 10 has a mounting surface 12 on which a test piece 21 is mounted, a stage unit 11 that can reciprocate a predetermined distance, and an upper side of the stage unit 11. And an upper support portion 15 provided with a support surface 16 that faces the mounting surface 12 and supports the test piece 22. The upper support portion 15 includes a pressing mechanism 17 that presses the test piece 22 supported on the support surface 16 toward the stage portion 11 with a predetermined pressure.

  The contacts to which fine sliding is applied are a convex contact test piece 22 having a spherical protrusion 23 (8B in FIG. 4: equivalent to a female terminal) and a flat test piece 21 (8A in FIG. 4: equivalent to a male terminal). Are configured by arranging the plated surfaces of each other to face each other. The convex contact test piece 22 was molded by pressing using an indenter having a spherical tip of R1.5 mm with respect to the plate material. As the test piece for contact, those cut out from Sn plating materials having respective plating layer configurations were used as described later.

  At the time of the fine sliding wear test, the flat test piece 21 is set and fixed on the stage 11 which can be reciprocated, and the convex contact test piece 22 is fixed on the arm 12 arranged above the stage portion 11 and is fixed. The electrical contact resistance was measured while sliding the stage 11 with the amplitude and frequency. In addition, the contact load applied predetermined load to the lower flat plate-shaped test piece 21 through the arm 12 and the convex contact test piece 22 from the pressing mechanism 17.

Example 1
First, assuming that both the female terminal and male terminal of the connector are formed using the same plating material, the above-described convex contact test piece and flat plate using the Sn-plated conductive material according to the first embodiment described above. The results of processing the test piece and evaluating the fine sliding wear property will be described.
A copper alloy plate having a thickness of 0.4 mm containing Mg: 0.7%, P: 0.005%, which is a representative of highly conductive terminal materials, is used as a base material, and a Ni plating layer, a Cu plating layer and a Sn plating layer are used. Are formed with a film thickness of 0.3 μm, 0.2 μm and 1.0 μm, respectively, and after reflow treatment by heating to a temperature at which Sn is melted, an Ag plating layer is formed on the Sn plating layer by 0.01 μm, It formed with the film thickness of 0.02 micrometer and 0.04 micrometer, and it immersed for 20 second in 45 degreeC warm water, and formed the Ag-Sn alloy layer, and produced the test piece (invention example 1-3). Moreover, the Sn plating test piece (Comparative Example 1) which did not form the Ag-Sn alloy layer was produced as a comparison. These test pieces were used to form contacts of the same plating, and the microsliding wearability was evaluated three times each. The average value curve is shown in FIG.

  As shown in FIG. 8, in all the test pieces, the contact resistance temporarily rises during the first 30 to 100 cycles, becomes stable for a while in the subsequent 200 to 1000 cycles, and slides further. As a result, the contact resistance rises unilaterally, and finally the measurement range is exceeded, resulting in poor contact. Here, when comparing the height of the first peak of each test piece (that is, the contact resistance value), the Sn-plated conductive material in which the surface of the present invention is coated with Ag-Sn fine particles (Invention Examples 1 to 1). 3) are all smaller than the normal Sn plating material (Comparative Example 1), and in particular, it was confirmed that the Ag—Sn alloy layer becomes thicker and the peak height becomes gradually smaller, and the increase in contact resistance can be suppressed. . In addition, when viewed from the resistance increase start point in the final stage, the normal Sn plating material (Comparative Example 1) starts to increase unilaterally in about 1000 cycles, but Sn plating coated with Ag-Sn fine particles. It can be seen that the conductive material (Invention Examples 1 to 3) has stable contact resistance up to 1200 to 1400 cycles and has wear resistance. That is, it was confirmed that the coating of Ag-Sn fine particles on the surface improves the overall fine sliding wear of the Sn plating layer, extends the service life of the terminal, and improves the electrical connection reliability. It was.

(Example 2)
In order to elucidate the mechanism of improving the fine sliding wear property by coating the Ag-Sn fine particles on the Sn plating layer surface, Ni-0.3 [mu] m, Cu-0 on the surface of the above-mentioned Cu-Mg-P copper alloy base material. .2 μm, Sn-1.0 μm plating and reflow treatment, Ag 0.04 μm plating was performed to form an Ag—Sn alloy layer, thereby preparing a test piece (Example 4 of the present invention). The specimen was subjected to a fine sliding wear test at 20 cycles, 50 cycles, 100 cycles, 500 cycles and 2000 cycles, respectively, and then SEM surface observation and EDX analysis were performed.

As shown in FIG. 9, Sn and Ag were detected at the contact center when the 20-cycle wear test in which the resistance was in a stable state, and it was confirmed that Ag ₃ Sn fine particles were dispersed in the Sn residue. It was. It is speculated that this stage is also in the plating layer region.

  As shown in FIG. 10, it was confirmed that the Sn—Cu alloy layer under the Sn film was exposed on the surface when the contact resistance started to increase in 50 cycles, and the formation of Sn oxide was also confirmed. Is done. From this, it is surmised that the increase in contact resistance at the 50th cycle is due to the oxidation of Sn grains generated by the wear of Sn.

  As shown in FIG. 11, the contact resistance rises most severely in 100 cycles, and at this point, Ni element from the Ni undercoat layer is also detected in addition to the Sn—Cu alloy and Sn oxide. From this, it is inferred that the increase in contact resistance or the deterioration in electrical connectivity is related to Ni having a high resistance and its oxide.

  As shown in FIG. 12, the material Cu is exposed on the surface in a region where the resistance becomes stable again after 500 cycles. At this point in time, the contact point is mainly made of Cu as the base material, and it is assumed that the fluctuation of the contact resistance is reduced.

  As shown in FIG. 13, it was confirmed that a large amount of Cu oxide residue was formed at the point of almost non-conducting state in 2000 cycles, and the cause of the final deterioration of the electrical connectivity was plating. It is considered that the layer was completely consumed and was oxidized to the base material.

Thus, in the fine sliding wear test, the temporary increase in contact resistance in the first stage (first time) is due to the oxidation of Sn in the plating film, and the deterioration in contact resistance in the final stage (second time) is caused by plating. It was found that this was due to substrate exposure and oxidation after the layer was consumed. Therefore, the reason why the Sn-plated conductive material in which the surface of the present invention is coated with Ag-Sn fine particles has excellent fine sliding wear characteristics is that by suppressing the oxidation of Sn by the surface Ag-Sn fine particles, or It is considered that the Ag ₃ Sn fine particles acted as conductive paths in the wear powder, thereby suppressing an increase in the initial contact resistance. In addition, the presence of hard Ag-Sn fine particles on the surface can reduce the wear of the plating film or delay the exposure of the base material. It is thought that the sliding wear characteristics could be improved.

(Example 3)
A description will be given of the result of evaluating the microsliding abrasion resistance by processing the above-described contact using a two-layer thin Sn-plated conductive material, omitting the Ni base plating as the first embodiment.
The base material is a copper alloy plate having a thickness of 0.25 mm containing Mg; 0.7% and P; 0.005%, and the Cu plating layer and the Sn plating layer are 0.3 μm and 0.5 μm thick, respectively. After forming and reflowing, an Ag—Sn alloy layer was formed on the Sn plating layer, and three types of test pieces having a Ag—Sn alloy layer thickness of 0 μm, 0.04 μm, and 0.06 μm (comparative example) 2. Invention Examples 5 and 6) were produced. These test pieces were used to form contacts of the same plating, and the fine sliding wear was evaluated three times. The average value curve is shown in FIG. Here, for convenience of explanation, the horizontal axis is expressed by logarithm (a) and linearity (b).

  As shown in FIG. 14A, when two-layer Sn plating is used, the first increase in contact resistance is as small as 30 to 40 mΩ regardless of the presence or absence of the Ag—Sn alloy layer. The plating material (Comparative Example 2) has a resistance peak position of about 20 cycles, whereas the Sn plating material covering the Ag-Sn fine particles (Examples 5 and 6) has about 40 cycles. As described above, it was confirmed that the wear resistance can be greatly improved (about twice) by suppressing the oxidation of Sn in the plating layer region.

  Further, as shown in FIG. 14B, when comparing the overall micro-sliding wear property, the normal Sn plating material (Comparative Example 2) starts a second increase in contact resistance from about 1200 cycles. The Sn plating material (Invention Examples 5 and 6) with Ag-Sn fine particles coated on the surface has about 1600 to 1900 cycles. By optimizing the thickness of the Ag-Sn alloy layer, the fine sliding wear is improved. It was found that it could be improved significantly.

Example 4
Thickness of 0.25 mm containing Ni: 2.0%, Zn: 1.0%, Sn: 0.5%, Si: 0.5%, which is the first embodiment and is a representative of highly conductive terminal material After forming a Cu plating layer and a Sn plating layer with a film thickness of 0.3 μm and 1.0 μm respectively and performing a reflow process, an Ag—Sn alloy layer is formed on the Sn plating layer. Three types of test pieces (Comparative Example 3 and Invention Examples 7 and 8) having a thickness of 0 μm, 0.04 μm, and 0.06 μm were formed. Using these test pieces, the fine sliding wear property was evaluated as a contact configuration of the same plating. The average result of the three measurements is shown in FIG.

  The first resistance increase peak is about 80 mΩ in the vicinity of 100 cycles, but the second resistance increase is about 1700 cycles for the normal Sn plating material (Comparative Example 3). It can be seen that the Sn plating material covering the Ag-Sn fine particles (Examples 7 and 8 of the present invention) is extended to about 2100 to 2300 cycles, and the microsliding wear property is greatly improved. Further, comparing the result of Example 1 with the result of Example 4, it can be seen that the first resistance increase value and the number of cycles are proportional to the thickness of the Sn plating film. In particular, when the film thickness of the Sn layer and the Ag—Sn alloy layer is the same and the Ni base is omitted, it can be seen that fine sliding wear at room temperature is good.

(Example 5)
Next, assuming the case where the female terminal and male terminal of the connector are formed using different plating materials, the results of evaluating the fine sliding wear will be described.
The test piece was manufactured by the manufacturing process of the first embodiment using a 0.4 mm-thick copper alloy plate containing Mg: 0.7% and P: 0.005% as the base material, Ni plating layer, Cu plating After forming a layer and a Sn plating layer with a film thickness of 0.3 μm, 0.2 μm and 1.0 μm respectively and performing a reflow process, an Ag layer is formed on the Sn plating layer with a thickness of 0 μm, 0.02 μm and 0.04 μm. The Ag—Sn alloy layer was formed by plating with a film thickness of 0.06 μm to prepare four types of test pieces (Comparative Example 4, Invention Examples 9 to 11). These test pieces are used as flat test pieces or male terminals, and the contact is made of a different type of plating material using a normal reflow Sn plating material as a convex contact test piece or a female terminal, and the microsliding wear resistance is evaluated. did. The average curve is shown in FIG.

  As shown in FIG. 16A, when Sn plating is used as one of the contacts, the contact resistance in the first plating layer region is almost the same due to the oxidation of Sn regardless of the presence or absence of the Ag—Sn alloy layer. Although the resistance rise peak of the normal Sn plating material (Comparative Example 4) is about 40 cycles, the peak of the Sn plating material covering the Ag-Sn fine particles (Invention Examples 9 to 11) is increased. Was about 80 to 120 cycles, and it was confirmed that the wear resistance of the plating layer region was improved by about 2 to 3 times.

  Further, as shown in FIG. 16 (b), when comparing the overall micro-sliding wear properties, the normal Sn plating material (Comparative Example 4) starts a second increase in contact resistance from about 900 cycles. The increase in resistance of the Sn plating material (Examples 9 to 11 of the present invention) whose surface is coated with Ag-Sn fine particles can be extended to about 1200 to 1700 cycles. It was also confirmed that the sliding wear was greatly improved. That is, if only one terminal is used for the contact or the connector, if the Sn plating material in which the surface of the present invention is coated with Ag-Sn fine particles is used, the reliability of electrical connection can be improved by improving the fine sliding wear property. It was found that the sex could be improved. In addition, the effect of improving the fine sliding wear resistance increases as the film thickness of the Ag—Sn alloy layer increases, but if the thickness exceeds a certain thickness (here 0.04 μm), the fine sliding wear resistance is more than that. Since there is a tendency to not improve or to decrease somewhat, it is considered that the optimum control of the Ag layer thickness is necessary in order to obtain the maximum effect of improving fine sliding wear.

(Example 6)
Furthermore, assuming a practical situation, as a female terminal and a male terminal of the connector, a contact (connector) by various combinations of the Sn plating conductive material coated with the Ag-Sn fine particles of the present invention and the normal reflow Sn plating. ) To evaluate the fine sliding wear property. Here, the configuration of the contacts was set as shown in Table 1.

  The test piece was prepared by using a copper alloy plate having a thickness of 0.25 mm containing Ni: 2.0%, Zn: 1.0%, Sn: 0.5%, Si; 0.5% in the first embodiment. After forming a Cu plating layer and a Sn plating layer with a film thickness of 0.3 μm and 0.86 μm respectively and performing a reflow treatment as a base material, an Ag layer is formed on the Sn plating layer by 0.04 μm, and Ag—Sn An Sn plating test piece coated with fine particles was prepared. Moreover, the normal reflow Sn plating material produced the Sn plating test piece of the same Sn film thickness in the same process. A curve obtained by averaging the three measurements is shown in FIG.

  As shown in FIG. 17, the resistance increase peak in the first plating layer region is almost the same regardless of the presence of the Ag—Sn alloy layer, but the Ag—Sn fine particles are present on either side or both sides of the contact. When using the Sn plating which coat | covers, it was confirmed that it is lower than normal Sn plating and suppresses the raise of the contact resistance by fine sliding wear. In addition, from the second increase in contact resistance, normal Sn plating starts to increase from about 1300 cycles, whereas the resistance increase of Sn plating with Ag-Sn fine particles coated on the surface increases to about 1800 to 2300 cycles. It can be extended, and it can be seen that the resistance stable region is wider than that of normal Sn plating. That is, it was recognized that the use of the Sn plating material coated with the Ag-Sn fine particles of the present invention even on one side of the contact can improve the overall fine sliding wear property of the contact.

  Furthermore, even when the Ag plating film thickness is the same, it was confirmed that when the Sn plating material in which the terminal on one side covers the Ag-Sn fine particles is used, the resistance increase is delayed compared to the case where both are used. . This is presumed that vibration is easily absorbed when combined with a hard plating layer (ie, Ag—Sn layer) and a soft plating layer (ie, Sn layer). In particular, it is more effective to use an Sn plating material in which the convex contact is coated with Ag-Sn fine particles. The convex portion that is most likely to be worn is consumed at the same time if the hard plating layer is used for the convex portion that is most likely to be worn. Therefore, it is considered that the wear resistance of the entire contact is improved. That is, if a Sn plating material in which at least one terminal is coated with Ag-Sn fine particles on the surface of the present invention is used for a contact or a connector, the micro-sliding wear resistance is greatly improved. It has been found that electrical connection reliability can be improved.

(Example 7)
Furthermore, in the high temperature environment, when using the Sn-plated conductive material covering the Ag-Sn fine particles of the present invention and the normal reflow Sn plating, the results of evaluating the fine sliding wear will be described.
The test piece was based on a copper alloy plate having a thickness of 0.4 mm containing Mg; 0.7% and P; 0.005%, and each of the Ni plating layer, the Cu plating layer and the Sn plating layer was 0.3 μm. , 0.2 μm and 1.2 μm film thickness were formed and reflow treatment was performed to prepare a reflow Sn plating material. Thereafter, an Ag plating layer having a thickness of 0.04 μm was formed on the Sn plating layer, and immersed in warm water at 45 ° C. for 20 seconds to form an Ag—Sn alloy layer. ) Was produced. For comparison, an Sn plating test piece (Comparative Example 6) in which no Ag—Sn alloy layer was formed was used.

  These test pieces were used to form contacts of the same plating, and the fine sliding wear property at 120 ° C. was evaluated three times each. Also, in the experiment, after setting each set of contacts at room temperature, turn on the heating power, heat up to 120 ° C at full speed and hold for 30 minutes, and then start measuring fine sliding wear. did. The average curve is shown in FIG.

  Although the overall fine sliding wear property is almost the same, the contact resistance increased to 200 mΩ or more in the normal reflow Sn plating at the time of 50 cycles, whereas the Sn coated with the Ag—Sn fine particles of the present invention. It can be seen that the plated conductive material can be suppressed to about 100 mΩ. This is because Ag-Sn fine particles suppress Sn oxidation in the plating film region in a high temperature environment.

(Example 8)
Next, as an example of using the Sn plating material not subjected to the reflow process according to the second embodiment described above, when using the Sn plating conductive material covering the Ag-Sn fine particles of the present invention and normal reflow Sn plating, respectively. The results of evaluating the fine sliding wear will be described.
The test piece is based on a copper alloy plate having a thickness of 0.15 mm containing Fe: 2.4%, Zn: 0.13%, P: 0.1%, which is a representative lead frame material, and Sn plating. After plating the layer by 1.0 μm, an Ag plating layer is formed with a film thickness of 0.02 μm and 0.04 μm, and immersed in warm water at 45 ° C. for 30 seconds to form an Ag—Sn alloy layer. Examples 16 and 17) were prepared. For comparison, an Sn plating test piece (Comparative Example 7) in which no Ag—Sn alloy layer was formed was used.
These test pieces were used to form contacts of the same plating, and the microsliding wearability was evaluated three times each. The average value curve is shown in FIG.

  In either case, the first increase in contact resistance is not observed, but by coating the surface with Ag-Sn fine particles, the second resistance increase period can be extended, and the entire fine sliding wear property is increased. Was confirmed to be improved over ordinary Sn plating. In addition, as in the case of using reflow Sn plating, it was recognized that the fine sliding wear property of the contact can be greatly improved by increasing the thickness of the Ag plating layer.

Example 9
As an example of using the Sn plating material not subjected to reflow processing according to the second embodiment, a copper alloy plate having a thickness of 0.15 mm containing Fe; 2.4%, Zn; 0.13%, P; 0.1% After plating the Cu plating and Sn plating layers with a film thickness of 0.3 μm and 2.0 μm, respectively, forming an Ag plating layer of 0.02 μm and immersing in warm water at 45 ° C. for 20 seconds to form Ag—Sn An alloy layer was formed to prepare a test piece (Invention Example 18). For comparison, an Sn plating test piece (Comparative Example 8) in which no Ag—Sn alloy layer was formed was used. These test pieces are used to form contacts of the same plating, and the curve of the average value is shown in FIG.

  It is confirmed that Sn plating material with Ag-Sn fine particles coated on the surface prolongs the second resistance rise time compared with normal Sn plating, and it is confirmed that the fine sliding wear property of the contact is improved. It was.

It is explanatory drawing of the Sn plating electrically-conductive material which is the 1st Embodiment of this invention. It is explanatory drawing which shows the state before the Ag-Sn alloy formation process of Sn plating electrically-conductive material shown in FIG. It is a process flow figure of the manufacturing method of Sn plating electrically-conductive material shown in FIG. It is explanatory drawing of the connector terminal using the Sn plating electrically-conductive material shown in FIG. It is explanatory drawing of the Sn plating electrically-conductive material which is the 2nd Embodiment of this invention. It is a process flowchart which shows the manufacturing method of the Sn plating electrically-conductive material which is the 2nd Embodiment of this invention. It is explanatory drawing which shows the outline | summary of a fine sliding abrasion test. 4 is a graph showing the results of a fine sliding wear test of Example 1. It is a test piece observation result after 20 cycles. It is a test piece observation result after 50 cycles. It is a test piece observation result after 100 cycles. It is a test piece observation result after 500 cycles. It is a test piece observation result after 2000 cycles. It is a graph which shows the fine sliding abrasion test result of Example 3. It is a graph which shows the fine sliding abrasion test result of Example 4. It is a graph which shows the fine sliding abrasion test result of Example 5. It is a graph which shows the fine sliding abrasion test result of Example 6. It is a graph which shows the fine sliding abrasion test result of Example 7. It is a graph which shows the fine sliding abrasion test result of Example 8. It is a graph which shows the fine sliding abrasion test result of Example 9.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Sn plating electrically-conductive material 2 Base material 3 Ni plating layer 4 Cu layer 5 Sn plating layer 6 Ag-Sn alloy layer 7 Ag layer 8 Fitting type connection terminal

Claims (7)

A conductive material for a terminal / connector comprising a conductive base material and a Sn plating layer made of Sn or Sn alloy formed on the base material,
The thickness in the stacking direction of the Sn plating layer is in the range of 0.1 to 15.0 μm,
An Ag—Sn alloy layer in which Ag—Sn fine particles are aggregated is formed on the surface of the Sn plating layer, and the average thickness of the Ag—Sn alloy layer is set within a range of 0.002 to 1.0 μm. Conductive material for terminals and connectors, characterized in that   The terminal / connector conductive material according to claim 1, wherein a Cu layer made of Cu or a Cu alloy is formed between the base material and the Sn plating layer.   3. The terminal according to claim 1, wherein a diffusion preventing layer for preventing diffusion of an element in the base material is formed on the base material. Conductive material for connectors. A fitting-type connection terminal having a male terminal and a female terminal that fit together,
A fitting type connection terminal, wherein at least one of the male terminal and the female terminal is formed of the terminal / connector conductive material according to any one of claims 1 to 3.   Both said male terminal and said female terminal are comprised with the electrically-conductive material for terminals and connectors as described in any one of Claims 1-3, and the said Ag-Sn alloy layer mutually opposes. The fitting type connection terminal according to claim 4, wherein the fitting type connection terminal is arranged.   Either one of the said male terminal and the said female terminal is comprised with the electrically conductive material for terminals and connectors as described in any one of Claims 1-3, The other of the said male terminal and the said female terminal is 5. The fitting type connection terminal according to claim 4, wherein the fitting type connection terminal is made of a Sn plating conductive material.   The said female terminal is formed with the convex part which protruded toward the said male terminal side, The said female terminal is comprised with the electrically conductive material for terminals and connectors as described in any one of Claims 1-3. The fitting type connection terminal according to claim 6, wherein the male terminal is made of an Sn-plated conductive material.

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