JP2003171790A - Plating material, method of manufacturing the same, and electric / electronic parts using the same - Google Patents

Abstract

(57) [Problem] To provide a plating material having both good heat resistance and insertability. SOLUTION: The surface of a conductive substrate 1 has a group 4 of the periodic table,
A base plating layer 2 made of any one of metals belonging to group 5, 6, 7, 8, 9 or 10 or an alloy mainly containing the same, and an intermediate layer made of Cu or Cu alloy The plating layer 3 and the surface plating layer 4 made of Sn or Sn alloy are formed in this order, and the thickness of the surface plating layer 4 is at least 1.9 times the thickness of the intermediate plating layer 3. Plating material.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plating material, a method for producing the same, and electric / electronic parts using the plating material. More specifically, the present invention relates to a plating material which has good heat resistance and is suitable as a material for a connector used in a high temperature environment such as an automobile engine room. Further, the present invention relates to a plating material suitable as a material for a fitting type connector or a contactor used in a high temperature environment because it has both good heat resistance and insertability / extractability.

[0002]

2. Description of the Related Art A material in which a plating layer made of Sn or Sn alloy is provided on a conductive base material made of Cu or Cu alloy is
It is known as a high-performance conductor having excellent conductivity and strength of a base material and good electrical contact characteristics, corrosion resistance, and solderability of Sn or Sn alloy. This material is widely used for various terminals and connectors.

As such a material, there is usually used a material produced by subjecting a base material to an undercoat of Cu or Ni and then directly plating an Sn or Sn alloy thereon. There is. This base plating layer has a base material component (alloy component such as Cu or Zn) of Sn or S on the surface.
It is provided to suppress diffusion into the n-alloy. In particular, when the base plating layer is a plating layer made of Ni or a Ni alloy, it has a great effect of delaying the above diffusion to Sn or the Sn alloy on the surface even in a high temperature environment. Therefore, the S
The characteristics of n and Sn alloys are secured.

However, even in the case of the above-mentioned material having the undercoat layer of Ni or Ni alloy, the following problems occur. For example, when it is used in a particularly high temperature place such as in the vicinity of an engine in an automobile engine room, Cu as a base material, Ni as a base material, and Ni and Ni alloys diffuse into the surface plating layer side over time. After a certain period of time, the surface plating layer is initially Sn or S
The surface plating layer made of Sn or Sn alloy disappears as a result of disappearing from the n alloy. As a result, the plated material does not exhibit its original performance.

Such a problem can be solved by increasing the thickness of the surface plating layer made of Sn or Sn alloy to prolong the disappearance time of the surface plating layer.
However, such countermeasures waste resources.
Moreover, not only that, but the plating material is, for example, a connector that fits a large number of terminals at the same time (fitting type connector)
When it is used for, it may cause a new problem that it becomes difficult to assemble it into the mating material.

By the way, in the fitting type connector, the male terminal and the female terminal are fitted to each other for electrical connection. In recent years, with regard to connector terminals mounted on automobiles, the amount of transmission information is increasing and electronic control is progressing. Along with that, the number of poles of the connector pin is increasing. In that case, if the insertion force of the terminal is the same as before, it is necessary to increase the insertion force of the connector by the increased number of pins. Therefore, it is strongly demanded to reduce the insertion force of a multi-pole connector pin.

As a terminal which meets such a demand, there is, for example, one in which an Au plating layer is formed on the surface of the terminal. The insertion force when using that terminal is reduced. However, since Au is expensive, on the other hand, there is a problem in that the manufactured terminals are expensive. As the connector terminal, generally, a conductive base material such as Cu having a surface plated with Sn is used. In the case of this terminal, since Sn is an easily oxidizable material, a hard Sn oxide film is always formed on its surface in the atmosphere.

When this terminal is inserted, the above-mentioned hard Sn oxide film is broken at the time of fitting with the mating material. Then, the unoxidized Sn plating layer located thereunder and the mating material come into contact with each other to realize electrical connection between the two. However, when the formed Sn plating layer is thin, the entire plating layer forms an oxide film, which makes it difficult for the oxide film to break during fitting. Moreover, the base material is Cu or Cu
When it is made of an alloy, when actually used in a high temperature environment, the Sn component of the thin Sn plating layer on the surface reacts with the base component to expose the Cu component to the surface, and a Cu oxide film is formed on the surface. To be done. As a result, contact reliability with the mating material is lost.

Such a problem can be suppressed by increasing the thickness of the Sn plating layer on the surface. However, in that case, a new problem arises that the insertion force with the mating material becomes large at the time of fitting. For this reason, particularly in a high temperature environment, it is possible to use expensive Au-plated terminals or only Sn-plated terminals with a thick Sn plating layer on the surface and a small number of pins. There was a problem.

By the way, when a plating layer made of Sn or a Sn alloy is formed on the surface of a terminal, in general, a gloss Sn is used.
Plating and reflow Sn plating are applied. Among these, in the case of a plating layer formed by bright Sn plating, the plating layer contains a large amount of additive components used during the plating process. Further, the crystal grain size of the plating Sn becomes fine. Therefore, the lubricity of the surface of the plating layer is excellent, and the amount of abrasion during fitting / sliding is reduced. As a result, the mating / unmating property at the time of fitting is excellent. However, since the crystal grain size is fine, when used in a high temperature environment, the diffusion rate of the components of the base material due to grain boundary diffusion increases, and the base material components may diffuse to the surface. . That is, the material of bright Sn plating is inferior in heat resistance.

On the other hand, in the case of reflow Sn plating, the surface plating layer is heated and melted after the entire plating process is completed. Therefore, in the formed reflow plating layer, the crystal grain size of the plating Sn is large, and the additive component mixed during the plating process is also removed. Therefore, even under a high temperature environment, the diffusion rate of the base material component based on the grain boundary diffusion becomes small. That is, the heat resistance of the material is improved. However, since the crystal grain size of the plating Sn is large, the amount of shaving at the time of fitting / sliding is large, and since the additive component is also small, the lubricity is poor and the insertability thereof is deteriorated.

Under these circumstances, various methods have been proposed in order to enhance the heat resistance and insertability of the Sn plating layer. For example, JP-A-8-7940 and JP-A-4-3
Japanese Patent No. 29891 discloses S for the purpose of improving heat resistance.
A method of forming a plating layer of a refractory metal, especially Ni, as a base of the n plating layer is disclosed. According to this method, when the temperature range is about 100 to 120 ° C., the Ni plating layer suppresses the reaction between the base material component (alloy component such as Cu and Zn) and the Sn component of the Sn plating layer, Moreover, since the reaction rate between Ni and Sn is small, a heat resistance effect can be obtained. However, in a high temperature environment of 140 ° C. or higher, the reaction rate between Ni and Sn increases and the surface Sn
Deterioration of the plating layer occurs and heat resistance cannot be obtained.

Further, Japanese Patent Laid-Open No. 11-121075 and Japanese Patent Laid-Open No. 10-302864 disclose a method of reducing the thickness of the Sn plating layer on the surface in order to improve the inserting / removing property. In the case of the surface Sn plating layer formed by this method, the amount of abrasion in fitting / sliding property is reduced and the insertability / extractability is improved. However, since the thickness of the Sn plating layer is thin, the Sn plating layer on the surface is alloyed and disappears due to diffusion with the base material even with a small heat history, and the contact resistance with the counterpart material increases.

As described above, in the case of the conventional plating material having the Sn plating layer formed on the surface thereof, there is a problem that it is very difficult to achieve both heat resistance and insertability / extractability.

[0015]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
Alternatively, in a plating material on which a Sn alloy plating layer is formed, the diffusion reaction between the plating layer and the base material or underlying plating layer is slowed even under a high temperature environment. Plating for the purpose of providing a plating material with good heat resistance, and also with good heat resistance as described above as well as good mating / unmating properties, making it suitable as a material for mating connectors and contacts used in high temperature environments. The purpose is to provide materials.

A further object of the present invention is to provide a method for producing the above-mentioned plating material, and an electric / electronic component using the plating material, such as a fitting type connector and a contact.

[0017]

In order to achieve the above-mentioned object, in the present invention, the surface of a conductive substrate is provided with groups 4, 5, 6, 7, 7 and 8 and 9 of the periodic table. Or 1
The undercoat plating layer made of any one metal included in Group 0 or an alloy containing it as a main component, the intermediate plating layer made of Cu or Cu alloy, and the surface plating layer made of Sn or Sn alloy are in this order. A plating material is provided.

In this case, the thickness of the base plating layer is 0.
05-2 μm, and the thickness of the intermediate plating layer is preferably 0.01-1 μm, and the thickness of the surface plating layer is 1.9 times or more the thickness of the intermediate plating layer. A plating material having a thickness of 10 mm is provided. In addition, in the present invention, on the surface of the conductive base material, a periodic table group 4, group 5, group 6, group 7,
An underplating layer made of any one of the metals belonging to Group 8, 9 or 10 or an alloy containing it as a main component; an intermediate plating layer made of Cu or a Cu alloy;
There is provided a method for producing a plating material, characterized in that a surface plating layer made of an n or Sn alloy is formed in this order, and preferably, after forming the intermediate plating layer, on the intermediate plating layer, Sn plating layer and Ag, Bi, C
There is provided a method for producing a plating material in which a plating layer made of at least one selected from the group consisting of u, In, Pb and Sb is formed in this order, and then reflow treatment or heat diffusion treatment is performed.

Further, the present invention provides an electric / electronic component using the above-mentioned plating material, specifically, a fitting type connector or a contactor.

[0020]

BEST MODE FOR CARRYING OUT THE INVENTION The plating material of the present invention has a four-layer structure as described later. The constituent material and thickness of each layer are designed as described later in relation to the above-mentioned improvement in heat resistance and the simultaneous improvement in heat resistance and insertability / extractability. First, in the plating material of the present invention, as shown in FIG. 1, as a whole, an underlying plating layer 2, an intermediate plating layer 3, and a surface plating layer 4 to be described later are arranged in this order on a conductive base material 1. Has been formed. In this plating material, the intermediate plating layer 3 is interposed between the base plating layer 2 and the surface plating layer 4, and the intermediate plating 3 exhibits the function described later, whereby the surface plating layer 4 disappears in a high temperature environment. Has the greatest feature where is suppressed.

First, the material of the conductive base material 1 is not particularly limited, and, for example, in consideration of its use as a connection connector, pure copper may be used depending on the required mechanical strength, heat resistance and conductivity. Copper alloys such as phosphor bronze, brass, nickel silver, beryllium copper, Corson alloy; pure iron, iron alloys such as stainless steel; various nickel alloys; composite materials such as Cu-coated Fe material and Ni-coated Fe material It may be appropriately selected from the above.

Of these materials, Cu or Cu alloy is preferable. If the conductive base material 1 is not a Cu-based material, the surface of the conductive base material 1 may be plated with Cu or a Cu alloy before being used for practical use, so that the adhesion and corrosion resistance of the plated film are further improved. The base plating layer 2 formed on the conductive base material 1 is provided to secure the adhesion strength between the base material 1 and the surface plating layer, and the components of the base material are thermally diffused to the surface layer side. It also functions as a barrier layer for preventing this. Specifically, elements of Group 4 of the periodic table (Ti, Zr, H
f) Group 5 element (V, Nb, Ta), Group 6 element (Cr,
Mo, W), Group 7 elements (Mn, Tc, Re), Group 8 elements (Fe, Ru, Os), Group 9 elements (Co, Rh, I)
r) It is formed of any one of Group 10 elements (Ni, Pd, Pt) or an alloy containing it as a main component.

Each of these metals has a melting point of 1000 ° C.
The above-mentioned refractory metals. And, for example, since the operating environment temperature of the connector is generally 200 ° C. or lower, it is a matter of course that the undercoat plating layer 2 is unlikely to cause thermal diffusion under such an operating environment. Effectively prevent heat diffusion to the. Of the above metals, Ni, C are used because of their price and ease of plating.
o and Fe are preferred. And as an alloy containing them as main components, for example, Ni-P, Ni-Sn, Co-
P, Ni-Co, Ni-Co-P, Ni-Cu, Ni-
Cr, Ni-Zn, Ni-Fe, etc. can be mentioned.

The above-mentioned base plating layer is, for example, PV.
It can be formed by a plating method such as the D method, but it is preferable to apply the wet plating method. Here, when the main purpose is to improve the heat resistance of the plating material, the thickness of the base plating layer 2 is preferably set within the range of 0.05 to 2 μm. This base plating layer 2
If the thickness of the base material is too thin, the above-mentioned effects cannot be sufficiently exhibited, and if it is too thick, the plating distortion becomes large and the base material 1
This is because it peels off easily and becomes dull.

When it is intended to improve the heat resistance of the plating material as well as the insertion / removal property, the thickness of the base plating layer 2 is not particularly limited, but the diffusion of the above-mentioned base material components on the surface layer side. In order to exert the preventive effect, 0.
It may be 25 μm or more. However, not only is it meaningless if it is made too thick, but it may cause processing cracks during processing into terminals. Therefore, considering the workability, the upper limit of the thickness is generally within the range of 0.5 to 2 μm. You can set it to.

Next, the intermediate plating layer 3 formed on the base plating layer 2 is made of Cu or Cu alloy. The intermediate plating layer 3 functions as a layer that prevents the components of the base plating layer 2 and the Sn component of the surface plating layer 4 from interdiffusing in a manner described later. Intermediate plating layer 3
The reaction rate between the Cu component and the Sn component of the surface plating layer 4 is higher than the reaction rate between the Cu component and the component of the underlying plating layer 2 (the metal or its alloy described above). Therefore, when this plating material is exposed to a high temperature environment, thermal diffusion of the Sn component of the surface plating layer 4 to the intermediate plating layer 3 progresses, and as a result, the intermediate plating layer 3 is as shown in FIG. Then, it is converted into a layer 3 ′ made of an Sn—Cu intermetallic compound. At the same time, Sn of the surface plating layer 4 of the plating material
The components diffuse and move toward the intermediate plating layer 3 starting from the interface with the intermediate plating layer 3 and are converted into the intermetallic compound. As a result, the thickness of the plating layer 4 ', which is a layer in which Sn (or Sn alloy) remains, becomes thin. Then, the Sn component in which the Cu component of the intermediate plating layer 3 diffuses from the upper layer side
Upon completion of receiving the Sn or Sn alloy, the mutual diffusion between the Sn or Sn alloy and Cu or the Cu alloy stops.

As a result, as shown in FIG. 2, a part of the intermediate plating layer 3 and the surface plating layer 4 of FIG. 1 becomes a layer 3'made of an intermetallic compound. The surface plating layer 4 in FIG.
Although its thickness is thin, it remains as a layer 4 ′ made of Sn or Sn alloy. As described above, the intermetallic compound layer 3 ′ is interposed between the base plating layer 2 and the layer 4 ′ made of Sn or Sn alloy, so that the reaction between the layer 4 ′ and the base plating layer 2 is suppressed. Will be done.

Therefore, in the case of this plating material, under the high temperature environment, it is used in the state of the layer structure shown in FIG. 2, that is, in the state where the mutual diffusion of Sn or Sn alloy and Cu or Cu alloy is suppressed. Will be. Therefore, the surface plating layer made of Sn or Sn alloy does not disappear during the use process. As the Sn-Cu intermetallic compound, Cu6Sn5 and Cu3Sn are well known. In the case of Cu6Sn5, one volume of Cu is 1.
Nine volumes are the compound produced by the reaction. Also Cu3S
In the case of n, it is a compound formed by reacting 0.8 volume of Sn with 1 volume of Cu.

Therefore, if the thickness of the surface plating layer 4 is 1.9 times or more the thickness of the intermediate plating layer 3, the above-mentioned mutual diffusion causes all the Cu components of the intermediate plating layer 3 to be the above-mentioned Sn-Cu. Even if it is converted into an intermetallic compound, the surface plating layer 4 ′ made of Sn or Sn alloy still remains. Then, the Cu component of the intermediate plating layer 3 is fixed as a Sn-Cu intermetallic compound, and its thermal diffusion is suppressed.

From the above, in the plating material of the present invention, the thickness of the surface plating layer 4 is preferably designed to be 1.9 times or more the thickness of the intermediate plating layer 3. By doing so, even if the plating material is in a high temperature environment, the surface plating layer 4'will always contain Sn or Sn.
Since the alloy remains as it is, its contact reliability is secured.

In this case, if the thickness of the intermediate plating layer 3 is too thin, for example, when the intermediate plating layer 3 is made of Cu, a large number of fine holes are present in the layer. Therefore, the Ni component and the Cu component of the base plating layer 2 will diffuse into the intermediate plating layer through these fine holes.
Further, if the thickness of the intermediate plating layer 3 is too thick, unless the thickness of the surface plating layer 4 is considerably increased, the Sn or S
The n alloy is completely consumed by the above-mentioned mutual diffusion, and eventually Sn or Sn alloy does not remain on the surface. To avoid this, if the surface plating layer 4 is made thick, it will have a large insertion resistance when the material is used with a mating connector.

Therefore, the thickness of the intermediate plating layer 3 is preferably set within the range of 0.01 to 1.0 μm. As the Cu alloy used for forming the intermediate plating layer 3, for example, Cu-Zn, Cu-Sn, Cu-Ni, N
i-Sn etc. can be mentioned. In that case, the amount of the Cu component needs to be an amount that does not inhibit the formation of the Cu—Sn intermetallic compound described above, but may be, for example, a value of 50% by mass or more.

In the case of the plating material of the present invention, the relationship between the thicknesses of the intermediate plating layer 3 and the surface plating layer 4 is as described above, that is, the thickness of the latter is set to be 1.9 times or more the thickness of the former. Surface plating layer 4 while maintaining
The thickness of can be reduced. As a result, the ease of insertion and removal can be improved. For example, if the thickness of the intermediate plating layer 3 is 0.49 μm or less, even if the thickness of the surface plating layer of the plating material is 1 μm or less, good insertability / extractability can be exhibited while ensuring sufficient heat resistance. it can.
Further, if the thickness of the intermediate plating layer 3 is 0.3 μm or less, the thickness of the surface plating layer 4 can be set to a thinner thickness of about 0.6 μm, which is preferable.

As described above, the surface plating layer 4 is S
It is formed of an n- or Sn-alloy and is provided to secure the electrical contact characteristics, corrosion resistance, and solderability as a plating material. In particular, it is preferable to form the Sn alloy because the insertability can be further improved. Sn in that case
As an alloy, for example, Sn, Ag, Bi, Cu, I
A preferable example is one containing one or more of n, Pb and Sb. All of these Sn alloys are
This is because the solderability is good and whiskers do not occur when the surface plating layer is formed.

Since Pb has a problem of flowing out to the environment, it is better to avoid using Sn alloy containing Pb as much as possible. This Sn alloy plating layer can be formed using a predetermined alloy plating bath, but it is preferable to form it by the following method because the manufacturing cost can be significantly reduced.

That is, after a base plating layer and an intermediate plating layer are formed on a base material, a Sn plating layer and one or more metals of Ag, Bi, Cu, In, Pb and Sb are further added. The plating layers are laminated in this order. The Sn plating layer described above may be a Sn alloy plating layer. Then, the entire laminated body is subjected to a reflow treatment or a thermal diffusion treatment to selectively perform thermal diffusion between the metal of the metal plating layer and Sn of the Sn layer (or Sn alloy plating layer). , Alloy them. For example, in the case of reflow treatment, the reflow treatment may be performed at a substantial temperature of 230 to 300 ° C. for 5 seconds or less, and in the case of thermal diffusion treatment, it may be performed at a temperature of 100 to 120 ° C. for several hours. This is because at this temperature, thermal diffusion between other layers hardly occurs.

In addition, in the plating material of the present invention, the thickness of each plating layer may be different between the base material and the base plating layer, between the base plating layer and the intermediate plating layer, or between the intermediate plating layer and the surface plating layer. Also, a thin plating layer of different materials may be interposed. Further, the material shape may be any shape such as a strip material, a round wire material, and a square wire material.

[0038]

EXAMPLES Examples 1 to 24, Comparative Examples 1 to 9 After electrolytic degreasing and pickling were sequentially performed on brass strips, a base plating layer, an intermediate plating layer and a surface plating layer were sequentially formed, and Table 2, Various plating materials shown in Table 3 were manufactured. In addition,
The plating conditions for forming each layer are as shown in Table 1.

[0039]

[Table 1]

The produced plating materials were heated to the temperatures shown in Tables 2 and 3, and the residual thickness of the surface plating layer at that time was measured according to the following specifications. Moreover, the dynamic friction coefficient at the initial stage was measured according to the following specifications. Remaining thickness: The plating material was left in an air bath at a temperature of 100 to 160 ° C. for 120 hours and then measured by a constant current melting method. Dynamic friction coefficient: Load 294 using Bowden type friction tester
Measured under conditions of mN, sliding distance of 10 mm, sliding speed of 100 M / min, and number of sliding times of 1. The mating material used was a brass strip having a plate thickness of 0.25 mm, plated with 1 μm of reflow Sn, and then overhanged to 0.5 mmR. The following results are collectively shown in Tables 2 and 3.

[0041]

[Table 2]

[0042]

[Table 3]

It is clear from Tables 2 and 3 that: (1) Comparing the example with the comparative example, the example shows that the surface plated layer (S
n) remains, and the coefficient of dynamic friction is small. The thicker the surface plating layer formed is, the thicker the surface plating layer (Sn) remains after heating and the more heat resistant it is. On the other hand, however, the coefficient of dynamic friction is smaller in the embodiment in which the thickness of the surface plating layer is thinner. For this reason, the thinner surface plating layer is more advantageous in terms of insertability and removal.

(2) As in Examples 7 to 10, even if the base plating layer is other than the Ni layer, it prevents diffusion of the base component (alloy component such as Cu or Zn) on the surface layer side. If there is, the same effect is obtained. Moreover, Examples 6 to 1
Even when the reaction speed of the intermediate plating layer with respect to the surface plating layer is higher than the reaction speed of the intermediate plating layer with respect to the underlying plating layer, the same effect is obtained.

When the thickness of the intermediate plating layer is thin as in the case of Example 13, the effect of suppressing the diffusion of the base plating layer and the surface plating layer is small. As is clear from comparison between Example 14 and Example 15, as the surface plating layer is thicker, the heat resistance is improved, and as it is thinner, the dynamic friction coefficient is smaller and the mating / releasing property is improved.

Examples 25-33, Comparative Examples 10-25 From the respective samples of Example 3, Example 5, Example 9, Example 12, Example 5, and Comparative Example 6, the tab width was 2.3 mm. I made male and female terminals. These male and female terminals are combined and fitted as shown in Table 4, and then the mated members are placed at a temperature of 160 ° C for 1
After heat treatment for 20 hours, the contact resistance between the terminals of each member was measured. The insertion at the time of fitting was performed at an insertion force speed of 2 mm / sec, and the peak strength at the time of insertion was measured as the insertion force. The average value of n = 5 was determined, and the results are shown in Table 4.

The contact resistance was measured by soldering a lead to the terminal and passing a current of 10 mA. The average value of n = 10 was calculated, and the results are shown in Table 4.

[0048]

[Table 4]

From Table 4, the following is clear. (1) Comparing the example with the comparative example, in the case of the example as a whole, the insertion force at the time of fitting is low and the contact resistance after heat treatment is low. In addition, the insertion force at the time of fitting in each of the examples and the comparative examples is a low value of approximately 5.3 to 6.5N. The insertion force of the male terminal of the embodiment is lower than that of the female terminal. This is because at the time of fitting, the female terminal side is in a point contact state and there is only one point to be shaved, but the male terminal side is in linear contact so that the shaved portion is linear. it is conceivable that.

Therefore, it is considered effective to reduce the thickness of the surface plating layer (Sn) on the male terminal side when a low insertion force is intended. In addition, the reason why the contact resistance after the heat treatment is low in the examples is that the contact reliability is improved because the surface plating layer (Sn) remains in the example terminals of the present invention even after the heat treatment. Is considered to be. On the other hand, when using the comparative example terminal,
The heat treatment causes the surface plating layer (Sn) to disappear and the contact resistance to increase.

[0051]

As is apparent from the above description, the plating material of the present invention is made of Cu between the base plating layer and the surface plating layer.
Alternatively, an intermediate plating layer made of a Cu alloy is interposed, and the thicknesses of the surface plating layer and the intermediate plating layer are designed so that Sn or Sn alloy of the surface plating layer remains even in a high temperature environment. .

Therefore, this plating material has good heat resistance, and also has good heat resistance and insertability / extractability. For example, the connector is placed in a high temperature environment such as an automobile engine room, and is also fitted. It is useful as a material for various electrical and electronic parts such as mold connectors and contacts.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a plating material of the present invention.

FIG. 2 is a cross-sectional view showing a layer structure when the plating material of FIG. 1 is exposed to a high temperature environment.

[Explanation of symbols]

1 Conductive substrate 2 Undercoat layer 3 Intermediate plating layer Interdiffusion layer of 3'Sn and Cu 4 Surface plating layer 4'Sn residual plating layer

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Satoshi Suzuki             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. (72) Inventor Morimasa Tanimoto             2-6-1, Marunouchi, Chiyoda-ku, Tokyo             Kawa Electric Industry Co., Ltd. F-term (reference) 4K024 AA03 AA04 AA14 AA21 AB03                       CA01 CA04 CA06 DB02

Claims (13)

[Claims] 1. A periodic table group 5 or 5 is formed on the surface of a conductive substrate.
Plating layer made of any one of the metals included in Group 6, 6, 7, 8, 9 or 10 or an alloy containing it as a main component, and an intermediate plating layer made of Cu or a Cu alloy And a surface plating layer made of Sn or a Sn alloy are formed in this order. 2. The plating material according to claim 1, wherein the surface plating layer is a layer subjected to reflow treatment. 3. The plating material according to claim 1, wherein the base plating layer is made of any one metal of Ni, Co, and Fe or an alloy containing the metal as a main component. 4. The Sn alloy is Ag, Bi, Cu, I
The plating material according to claim 1, containing at least one selected from the group consisting of n, Pb, and Sb. 5. The thickness of the base plating layer is 0.05 to 2
μm, and the thickness of the intermediate plating layer is 0.01
The plating material according to any one of claims 1 to 4, which has a thickness of ˜1 μm. 6. The plating material according to claim 1, wherein the thickness of the surface plating layer is 1.9 times or more the thickness of the intermediate plating layer. 7. The thickness of the intermediate plating layer is 0.05 to 0.5.
The plating material according to claim 6, which has a thickness of 49 μm. 8. The plating material according to claim 7, wherein the surface plating layer has a thickness of 1 μm or less. 9. The plating material according to claim 1, wherein the conductive base material is made of Cu or a Cu alloy. 10. A surface of a conductive substrate is provided with a periodic table group 4 group,
An underplating layer made of any one of the metals belonging to Group 5, 6, 7, 8, 9, or 10 or an alloy containing it as a main component, and an intermediate plating made of Cu or a Cu alloy. A method for producing a plating material, comprising forming a layer and a surface plating layer made of Sn or Sn alloy in this order. 11. A Sn plating layer or a Sn alloy plating layer, and Ag, Bi, C on the intermediate plating layer.
A plating layer made of at least one selected from the group consisting of u, In, Pb, and Sb is formed in this order, and then,
The method for producing a plating material according to claim 10, wherein the reflow treatment or the thermal diffusion treatment is performed. 12. An electric / electronic component comprising the plating material according to any one of claims 1 to 9. 13. The electric / electronic component according to claim 12, wherein the electric / electronic component is a fitting type connector or a contact.