JP2010267418A - Connector - Google Patents

Abstract

Provided is a connector for an electrical / electronic component that includes a male terminal and a female terminal, which is easy to manufacture, has stable electrical connectivity, and has improved insertion / removability.
A connector in which a male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6 N or more and 6.0 N or less are connectable to each other, the male terminal and A connector in which at least one outermost surface of the female terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.
[Selection] Figure 3

Description

  The present invention relates to a connector for electrical and electronic parts including a male terminal and a female terminal.

  For example, a connector used for connecting an electric wire of an automobile or the like is generally coated with a metal such as tin (Sn) or tin alloy on a conductive substrate (hereinafter referred to as a substrate as appropriate) such as a copper (Cu) alloy. Male and female terminals with layers are used. The male terminal and the female terminal are respectively housed in a housing and configured as a male connector and a female connector, respectively.

  In recent years, with the progress of electronic control, connectors have become multipolar, so a great deal of force is required when inserting and removing male connector terminal groups and female connector terminal groups. There is a need to reduce power. In particular, since it is difficult to insert and extract in a narrow space such as in an engine room of an automobile, reduction of the insertion and extraction force is strongly demanded. When the insertion / extraction force is high, it is necessary to introduce equipment using the lever principle in order to reduce the work load of the assembling worker.

  As a method of reducing the insertion / extraction force, there is a method of weakening the contact load (contact pressure) between the terminals. If this method is adopted, a fretting phenomenon occurs between the contact surfaces of the terminals, resulting in poor conduction between the terminals. May occur.

The fretting phenomenon is that the soft Sn plating layer on the surface of the terminal wears and oxidizes due to fine sliding that occurs between the contact surfaces of the terminal due to vibration, temperature change, etc., and becomes a wear powder having a large specific resistance. When this phenomenon occurs between terminals, a connection failure occurs. This phenomenon is more likely to occur as the contact load between the terminals is lower. This phenomenon is less likely to occur by thinning the Sn plating layer on the connector terminal surface, but it is difficult to completely prevent this phenomenon from occurring.
For this reason, conventionally, female terminals with high contact loads have been used, and it has not been possible to meet the low insertion / removal force demanded in assembly work.

As a technique for reducing the contact load of the female terminal of the connector, there is a technique in which a plating layer of nickel, copper, and tin is sequentially laminated on a copper alloy base material so that the thickness of the tin plating layer is 1.1 μm or less. However, it is said that a contact load of 25 N or less is sufficient (see Patent Document 1), and cannot be applied as a terminal material for a multipolar connector for which a lower contact load is required.
In addition, a conductive material for connecting parts in which a Cu—Sn alloy coating layer and a Sn coating layer are formed in this order on the surface of the base material has been proposed (see Patent Document 2), but this material merely exhibits a low friction coefficient. It cannot be said that the low insertion effect is great when used for connector terminals. There is a limit to reducing the connector insertion / removal force only by selecting the material.

JP 2003-151668 A JP 2006-77307 A

  An object of the present invention is to provide a connector for an electrical / electronic component that includes a male terminal and a female terminal, which is easy to manufacture, has stable electrical connectivity, and has improved insertion / extraction.

The above-mentioned subject is achieved by the following means.
(1) A connector configured such that a male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6 N or more and 6.0 N or less can be connected to each other, the male terminal and the A connector characterized in that at least one outermost surface of the female terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.
(2) The connector according to (1), wherein the outermost surface of the male terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.
(3) A connector configured such that a male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6 N or more and 6.0 N or less can be connected to each other, and the male terminal and the A connector, wherein an outermost surface of at least one contact portion of a female terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.
(4) The connector according to (3), wherein the outermost surface of the contact portion of the male terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm. .

(5) A connector configured such that a male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6 N or more and 6.0 N or less can be connected to each other, the male terminal and the At least one outermost surface of the female terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and a Cu—Sn alloy having a thickness of the dispersed pure Sn layer or more. A connector characterized by being formed of a metal material as a layer.
(6) The outermost surface of the male terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and Cu—Sn having a thickness of the dispersed pure Sn layer or more. The connector according to (5), which is formed of a metal material that is an alloy layer.
(7) A connector configured such that a male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6 N or more and 6.0 N or less can be connected to each other, and the male terminal and the The outermost surface of at least one contact portion of the female terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and a Cu having a thickness of the dispersed pure Sn layer or more. A connector characterized by being formed of a metal material that is a Sn alloy layer.
(8) The outermost surface of the contact portion of the male terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, and has a thickness of 0.10 μm or more and 3.0 μm or less and a thickness of the dispersed pure Sn layer or more. The connector according to (7), wherein the connector is formed of a metal material that is a Cu-Sn alloy layer.
In the present invention, “outermost surface” means “outermost layer and its surface”.
Further, in the present specification, “to” is used in the sense of including the numerical values described before and after it as a lower limit value and an upper limit value.

  ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to set it as a low contact load, suppressing a fretting phenomenon, and can provide the connector which has a low insertion / extraction force terminal. The connector of the present invention maintains the electrical connection reliability of the male and female terminal contacts, despite the low insertion / extraction force.

It is a perspective view which shows the male terminal of the connector of one embodiment of this invention. It is a perspective view which shows the internal structure of the female terminal of the connector of one embodiment of this invention. It is a schematic sectional drawing explaining the connection state of the connector of this invention. It is an example of the graph of the displacement-load by contact load measurement. It is a perspective explanatory view showing an embodiment of a metal material of the present invention. It is a perspective explanatory view of the plating layered product used for manufacture of the metal material of the present invention. It is a SEM photograph which shows an example of the measurement site | part using an AES apparatus. It is the photograph of the mapping image (Sn-Cu-Ni map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is the photograph of the mapping image (Sn map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is the photograph of the mapping image (Cu map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is the photograph of the mapping image (Ni map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is a SEM photograph which shows an example of the measurement site | part using an AES apparatus. It is a photograph of the mapping image (Sn-Cu-Ni map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is a photograph of the mapping image (Sn map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is a photograph of the mapping image (Cu map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. It is a photograph of the mapping image (Ni map) obtained using the AES apparatus which shows the metal structure of the measurement part shown in FIG. FIG. 13 is a schematic plan view illustrating an example of a Cu—Sn alloy and Sn distribution on the surface of the Cu—Sn alloy layer corresponding to a part of the measurement unit illustrated in FIG. 12. FIG. 13 is a schematic plan view illustrating another example of the Cu—Sn alloy and Sn distribution on the surface of the Cu—Sn alloy layer corresponding to a part of the measurement unit illustrated in FIG. 12. It is explanatory drawing of a micro sliding test method. It is explanatory drawing of an insertion force test.

  The connector of the present invention is configured so that a male connector having a male terminal and a female connector having a female terminal can be connected to each other, and the outermost surface of at least one of the male terminal and the female terminal has a thickness of 0. It is formed of a metal material that is a Cu—Sn alloy layer of 10 μm or more and 3.0 μm or less. A male connector having a male terminal is generally configured by housing one or more male terminals in a housing (not shown). Similarly, a female connector having a female terminal is generally configured by housing one or more female terminals in a housing (not shown). Since the matters relating to the connector are general matters in the present invention, illustration and detailed description thereof are omitted.

  Moreover, the said metal material is suitably produced, for example by plating mainly elements, such as Ni, Cu, Sn, on an electroconductive base material. The plating type, plating thickness configuration, presence / absence of heat treatment, time of heat treatment temperature with heat treatment, and presence / absence of cooling, cooling time with cooling, etc. are used as a total manufacturing cost and It is appropriately set according to the required quality of the part.

  FIG. 1 is a perspective view showing a male terminal 10 of a connector according to an embodiment of the present invention. The male terminal 10 includes a tab 11 that is a connection portion with the female terminal 20 and a wire barrel 12 that is a crimping portion that crimps the wire. The tab 11 is formed in a flat plate shape, and its upper surface and lower surface are each finished to a smooth surface.

FIG. 2 is a perspective view showing the internal structure of the female terminal 20 of the connector according to one embodiment of the present invention. The male terminal 10 shown in FIG. 1 and the female terminal 20 shown in FIG. 2 can be connected to each other and constitute a connector. In FIG. 2, the contact portion of the female terminal 20 with the male terminal 10 has a hollow box shape, and includes a tongue piece 21, a dimple 22 and a bead 23 therein.
The dimple 22 is a convex member provided at the upper part of the tongue piece 21, and makes point contact with the lower surface of the tab 11 when connected to the male terminal 10. The tongue piece 21 has a function as a spring for applying a contact pressure, that is, a pressure for pressing the dimple 22 against the tab 11. The bead 23 is also a convex member, contacts the upper surface of the tab 11, and receives contact pressure exerted on the tab 11 by the dimple 22.

  At least a part of at least one of the male terminal 10 and the female terminal 20 is formed of a metal material whose outermost surface is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm. By using such a metal material for the outermost surface, the friction coefficient can be lowered and the fretting phenomenon can be suppressed. The Cu—Sn alloy layer preferably has a thickness of 0.20 μm to 1.0 μm, and more preferably 0.30 μm to 0.60 μm. Only a part of the male terminal 10 and / or the female terminal 20 may be formed of the metal material. In that case, it is preferable that at least a contact portion is formed of the metal material.

  As the metal material, a material in which a pure Sn layer is dispersed in the Cu—Sn layer can be preferably used. In this case, the dispersed pure Sn layer has a maximum thickness of 0.01 to 0.50 μm, preferably 0.03 to 0.30 μm. At this time, the Cu—Sn alloy layer has a thickness equal to or greater than the thickness of the dispersed pure Sn layer. The dispersed pure Sn layer referred to here is a layer in which at least a part of pure Sn is exposed on the surface of the Cu—Sn alloy layer and dispersed in an island shape or a dot shape in a cross-sectional view. . The action of dispersed pure Sn will be described later.

When the outermost layer of either the male terminal 10 or the female terminal 20 is formed of a metal material that is the Cu—Sn alloy layer, only the female terminal 20 has a Cu—Sn alloy layer. It is preferable that only 10 has a Cu—Sn alloy layer, and it is more preferable that both the male terminal 10 and the female terminal 20 have a Cu—Sn alloy layer.
In the present invention, the state of the outermost layer of the metal material means the initial state of the connector.

  When the male terminal 10 is connected to the female terminal 20, the tab 11 is inserted into the gap between the tongue piece 21 and the bead 23 as shown in the schematic sectional view of FIG. 3. At this time, the bead 23 is in sliding contact with the upper surface of the tab 11, and the dimple 22 is in sliding contact with the lower surface of the tab 11. When the tab 11 is completely inserted, the tab 11 is held in pressure contact with the bead 23 and the dimple 22 in contact with the tab 11, whereby the electrical connection between the male terminal 10 and the female terminal 20 is achieved. Is configured.

When the connection is made in this way, on the male terminal 10 side, the upper surface and the lower surface of the tab 11 are contact portions. On the other hand, on the female terminal 20 side, the dimple 22 and the bead 23 are contact portions.
In the present invention, the contact portion means that when the male terminal is inserted into the female terminal, the dimple of the female terminal, the surface where the bead and the tab of the male terminal are in contact, and the female terminal after inserting the male terminal into the female terminal The dimple and the surface where the bead and the tab of the male terminal contact each other.

  Moreover, when there is a difference in surface hardness between the male terminal 10 and the female terminal 20, the softer one is likely to slip, and the insertion force decreases as the displacement amount decreases. In consideration of this, it is preferable to harden the material on the side with the larger contact area corresponding to the locus of the contact portion of each of the male terminal and the female terminal at the time of connection. Accordingly, it is possible to reduce the connector insertion / removal resistance, reduce the insertion force required at the time of assembling the connector, improve the work efficiency of the assembly work, and reduce the fatigue of the worker.

In general, the male terminal has a flat shape so that it can be easily inserted, while the female terminal has a shape that has a bending function on one or both of the upper and lower surfaces of the inner surface and has the function of a spring. is doing. Further, the contact on the female terminal side is normally protruded to the inserted male terminal side. For this reason, the male terminal may be manufactured by punching a flat plate as it is, while the female terminal is often manufactured by bending, so the female terminal is more easily processed by a metal material. It is preferable that the hardness of the is lower than that of the male terminal. In particular, in the case where a severe bending process is involved in the manufacturing process in order to cope with the recent miniaturization, the present invention having a female terminal that is easy to process is suitable.
In addition, when the terminal is inserted due to the structure, the contact area corresponding to the locus of the contact portion of the male terminal is larger than the contact area corresponding to the locus of the contact portion of the female terminal. As a target (forming a Cu—Sn alloy layer having a thickness of 0.10 μm or more and 3.0 μm or less on the outermost surface), it is effective to select a male terminal.

The connector of this invention has the female terminal of the contact structure from which the contact load of a male terminal and a female terminal will be 0.6-6.0N. The contact load is preferably 1.0 to 5.0N, and more preferably 2.0 to 4.0N.
The “contact load” in the present invention is a force with which the contact points of the terminals are pressed against each other. However, when there are a plurality of contacts on the contact surface, the sum is indicated.
For example, when the female terminal has a spring piece having one dimple shape (22) on one side and a bead shape (23) fixed on the opposite side as shown in FIG.
Spring reaction force at terminal fitting = contact load. This contact load is obtained with a micro load meter using a disassembled female terminal, considering the value obtained by tab gap measurement with a microscope as displacement (indentation displacement assuming a male terminal is inserted). It can be measured by a method of reading from the obtained spring characteristics (displacement-load graph). The tab gap at this time is the distance between the bead and the dimple of the female terminal. The spring characteristics are measured by a method such as pushing down the dimples with a dedicated jig attached to the micro load meter.
The contact load can be adjusted by preparing a displacement-load graph in advance by the measurement method and setting a tab gap obtained from the displacement value for the desired contact load. Since the displacement is obtained by subtracting the tab gap of the female terminal from the tab thickness of the male terminal, if the tab thickness of the male terminal is determined, the tab gap of the female terminal having a desired contact load is determined.
According to the present invention, since the contact structure with such a low contact load can be inserted / removed with a small force, the burden of the assembly work can be greatly reduced.

  This connector is mounted on an automobile as, for example, an in-vehicle connector, but the application of the connector according to the present invention is not limited to in-vehicle use, and can be applied to any connector such as an electric / electronic device.

  Next, a metal material having a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm on the outermost surface constituting the connector of the present invention will be described.

The metal material forming at least one of the male terminal and the female terminal of the connector of the present invention is one in which a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm is provided on the outermost surface (hereinafter referred to as connector use). Called metal materials). Preferably, a material in which the Cu concentration is gradually decreased toward the surface, a material in which Sn or Sn alloy is dispersed in the Cu—Sn alloy layer, or the like is used. Part of the Sn or Sn alloy may be exposed on the surface of the Cu—Sn alloy layer.
The layer immediately below where the Cu—Sn alloy layer is provided is not particularly limited. For example, the Cu—Sn alloy layer may be provided on a conductive substrate, or Cu may be formed on a conductive substrate. , Ni, Cu alloy, Ni alloy, Fe, Fe alloy, Co, or a Co or Co alloy, or a metal or alloy layer made of any one or two of them, and the outermost Cu-Sn alloy layer on it. It may be provided.

  FIG. 5 is a perspective view showing a connector metal material according to a preferred embodiment of the present invention. On the conductive substrate 1, an underlayer 2 made of Ni, an intermediate layer 3 made of Cu thereon, and an upper layer thereof. This is a connector metal material 5 provided with a Cu—Sn alloy layer 4.

  The connector metal material 5 includes, for example, a Ni layer (N layer) 2a, a Cu layer (C layer) 3a, and a Sn layer (S layer) 4a on a conductive substrate 1 as shown in the perspective view of FIG. Plating laminate 6 is produced by plating in order, and this is heat treated to thermally diffuse and react Cu of C layer 3a and Sn of S layer 4a to form an outermost Cu-Sn alloy layer. Manufactured. During this heat treatment, thermal diffusion of the base component is blocked by the N layer 2a. The volume ratio (S / C) between the S layer 4a and the C layer 3a takes into account the required thickness of the Cu—Sn alloy layer 4, and further the S layer 4a disappears after the heat treatment, so that the C layer 3a remains as an intermediate layer. However, since the thickness of the C layer 3a after the heat treatment (the thickness of the intermediate layer 3) does not need to be strictly defined, the design of the plated laminate 6 and the heat treatment thereof can be easily performed. Therefore, the connector metal material 5 used in the present invention is easy to manufacture and excellent in productivity.

  When the outermost Cu—Sn alloy layer is formed by thermally diffusing and reacting Cu of the C layer 3a and Sn of the S layer 4a, it is preferable to perform a cooling treatment after the heat treatment. . By performing the cooling process under appropriate conditions, it is possible to form the diffusion of Cu and Sn in a gradation rather than a layered manner. Further, it is possible to form pure Sn partially on the outermost surface.

  Although the said heat processing can be performed by arbitrary methods, Preferably, it is the process which passes the plating laminated body 6 for 3 to 20 second in the reflow furnace of 300-800 degreeC in furnace temperature.

  Moreover, although said cooling process can be performed by arbitrary methods, Preferably it is 1-100 second in the liquid of 20-80 degreeC, More preferably, it is 1-60 seconds in the gas of 20-60 degreeC. It is performed by letting it pass through the liquid at 20 to 80 ° C. over 1 to 100 seconds. More preferably, it is carried out by passing water at 30 to 50 ° C. over 5 to 15 seconds.

  The thickness of the C layer 3a of the plating laminate 6 is usually 0.01 μm or more. The upper limit is preferably about 5.0 μm in consideration of practical aspects, material costs, manufacturing costs, and the like. The thickness of the C layer 3a is more preferably 0.05 μm or more and 0.5 μm or less. When the C layer 3a is Cu, if the C layer 3a is thin, many fine holes are generated in the C layer (intermediate layer 3) after the heat treatment, and the barrier function as the intermediate layer may be lost. When Cu is Cu, the thickness of the C layer 3a is preferably slightly thicker than that of the Cu alloy.

In the present invention, since it takes a long time depending on the thickness of the S layer 4a to completely react, Sn may be dispersed and remain in the Cu-Sn alloy layer 4 in the form of dots or islands after the heat treatment. However, this hardly reduces the function of the connector metal material 5. In this case, a part of the dispersed Sn or Sn alloy may be exposed on the surface of the Cu-Sn alloy layer 4, but the exposed area of the exposed Sn or Sn alloy is larger than the surface area of the dispersed Sn or Sn alloy. Is preferably sufficiently small.
In the product after reflow treatment, if the C layer 3a remains excessively thick in the base, it is usually not desirable because they may diffuse to the surface when subjected to a thermal load and further lead to oxidation / resistance increase. However, if Cu—Sn is present in the outermost surface layer and pure Sn is dispersed (residual), the pure Sn receives the diffusion of Cu remaining excessively in the base, and the copper diffuses to the outermost surface.・ Oxidation can be suppressed and resistance increase can be prevented.

Furthermore, when Sn is dispersed in the outermost Cu—Sn alloy layer 4, even if the Cu layer (intermediate layer) 3 remains thick, the dispersed Sn reacts with the excess and diffuses. The diffusion effect is remarkable under high temperature environment. Therefore, it is possible to take a wider design area for the plating manufacturing conditions, and the characteristics can be maintained for a long time even in a high temperature environment. Thus, what disperse | distributed Sn or Sn alloy in 4 in a Cu-Sn alloy layer is also an example of the metal material which can be used for this invention. Here, Sn or Sn alloy dispersed in the form of dots or islands in a cross-sectional view, for example, Sn in the Cu-Sn alloy layer of the mapping image obtained using an AES (Auger Electron Spectroscopy) apparatus, for example. Or the Sn alloy area occupancy (approximately equal to the volume occupancy) of 0 to 60%. Further, Sn or Sn alloy dispersed in an island shape in a cross-sectional view may be partially exposed on the outermost surface or not exposed on the outermost surface. Typically, a part of the outermost surface exposed is a Cu-Sn alloy part in the Sn or Sn alloy exposed on the outermost surface in a cross-sectional view, and Sn in an outermost plan view. There is also a Sn alloy in a donut shape. Further, the Sn or Sn alloy dispersed and remaining only in the vicinity of the surface of the Sn or Sn alloy dispersed and remaining in the Cu-Sn alloy layer 4 may be dissolved and removed by a chemical. The remaining Sn or Sn alloy dispersed and remaining only in the vicinity of the surface of the Cu—Sn alloy layer 4 is removed if it exists in a state protruding from the surface of the Cu—Sn alloy layer 4 because it causes fretting as described above. It may be desirable.
What can be used in the present invention includes a dispersed pure Sn layer whose outermost surface has a maximum thickness of 0.01 to 0.50 μm as described above, and has a thickness of 0.10 μm or more and 3.0 μm or less. There is a metal material that is a Cu-Sn alloy layer having a thickness equal to or greater than that.

  In addition, the said Cu-Sn alloy layer can be formed even if it directly Sn-plats on a copper or copper alloy base | substrate. In this case, the C layer in the plated laminate is the substrate itself, and an Sn layer (S layer) is formed thereon by Sn plating. After the Sn plating, heat treatment is performed to thermally diffuse and react the Cu of the base and Sn of the plating layer to form a Cu—Sn alloy layer as the outermost layer. The Cu layer and the Sn layer are formed by plating. Same as the case. However, when Sn plating is directly performed on the substrate, for example, it is preferable to produce by subjecting a base material having a thickness of 0.25 mm to 1 μm Sn plating, and further applying a heat treatment at 750 ° C. for 6 seconds.

7 to 11 are mapping images obtained by using an AES apparatus as an example of the metal material of the present invention. Here, first, a 30-degree oblique section is created by FIB (Focused Ion Beam) at a sample inclination of 60 degrees and used as an Auger measurement (AES) analysis sample. The sample was tilted and analyzed so that an AES electron image was obtained. The outermost Cu—Sn alloy layer was present as a layer in which Cu—Sn intermetallic compounds such as Cu ₆ Sn ₅ , Cu ₃ Sn, and Cu ₄ Sn were mixed.

  FIG. 7 is an SEM photograph (horizontal width: 11.7 μm) of the AES measurement section of the sample cross section. 8 to 11 are mapping images showing the metal structure of the measurement unit shown in FIG. 8 is a Sn-Cu-Ni map showing Sn, Cu, and Ni in different shades of colors, FIG. 9 is a Sn map showing Sn in white, FIG. 10 is a Cu map showing Cu in white, and FIG. 11 is Ni in white. It is Ni map shown by.

7 to 11, 31 indicates the surface of the Cu—Sn alloy layer, 32 indicates the substrate, 33 indicates the underlayer, 34 indicates the intermediate layer, and 35 indicates the Cu—Sn alloy layer. Further, in FIG. 9, the Cu—Sn alloy layer 35 is shown in white, and the brighter portion on the surface 31 side indicates that a lot of Sn is contained. In FIG. 10, the underlayer 33 is shown in black, and the underlayer 33 does not substantially contain Cu. In FIG. 11, only the base layer 33 is shown in white, indicating that Ni has not diffused outside the base layer 33.
Moreover, as shown in FIGS. 8-11, it turns out that Sn or Sn alloy hardly remains in the Cu-Sn alloy layer 35 (the area which Sn or Sn alloy occupies is 0 to 10%). Furthermore, as shown in FIG. 10, it turns out that Cu is decreasing gradually toward the surface.

12 to 16 are mapping images obtained by using the AES apparatus in the same manner as FIGS. 8 to 11 of the metal material of another example of the present invention. FIG. 12 is an SEM photograph (horizontal width: 11.7 μm) of the AES measurement section of the sample cross section. 13 to 16 are mapping images showing the metal structure of the measurement unit shown in FIG. FIG. 13 is a Sn-Cu-Ni map showing Sn, Cu, and Ni in different shades of colors, FIG. 14 is a Sn map showing Sn in white, FIG. 15 is a Cu map showing Cu in white, and FIG. It is Ni map shown by. 12 to 16, reference numeral 31 denotes a surface of the Cu—Sn alloy layer, 32 denotes a substrate, 33 denotes a base layer, 34 denotes an intermediate layer, and 35 denotes a Cu—Sn alloy layer. In FIG. 13, Sn or Sn alloy 36 whose color is shown is dispersed in islands in the Cu—Sn alloy layer 35. Further, in FIG. 14, the Cu—Sn alloy layer 35 is shown brightly, and the whiter island-shaped portion on the surface 31 side indicates that Sn or Sn alloy 36 is included. Further, FIG. 15 shows that the underlying layer 33 and the island-shaped Sn or Sn alloy 36 are substantially free of Cu. In FIG. 16, only the base layer 33 is shown in white, indicating that Ni has not diffused outside the base layer 33.
Moreover, as shown in FIGS. 13 to 16, the area occupied by Sn or the Sn alloy in the Cu—Sn alloy layer on the Ni layer was 30 to 60%. Further, as shown in FIG. 15, it can be seen that Cu gradually decreases toward the surface.

In the metal material of this example, as shown in FIG. 13, Sn or Sn alloy 36 is dispersed in an island shape in Cu—Sn alloy layer 35 in the cross-sectional view, and Sn or Sn alloy dispersed in an island shape. A part of 36 is exposed on the surface 31 of the Cu—Sn alloy layer 35 and, as schematically shown in FIGS. 17 and 18, the Sn or Sn alloy exposed on the surface of the Cu—Sn alloy layer. A Cu—Sn alloy part is present inside (Sn or Sn alloy appears to be exposed in a substantially donut shape on the Cu—Sn alloy layer from the surface). 17 and 18, 4 is the outermost Cu—Sn metal plating layer, 4 b is the Cu—Sn intermetallic compound, and 4 c is the Sn or Sn alloy forming the Sn layer (S layer) in FIG. 2. The Cu—Sn intermetallic compound 4 b is connected to the Cu—Sn alloy layer 4 to form a part of the outermost layer.
In such a state, the volume ratio of the S layer and the C layer of the plated laminate is smaller than 1.90 (a condition that no Sn layer remains on the surface of the metal material when all Sn is Cu—Sn alloy), and This occurs when the heat treatment is terminated by, for example, rapid cooling in a state where Sn is not completely Cu—Sn alloyed. In such a state, since the harder Cu-Sn alloy existing around the Sn or Sn alloy exposed on the surface of the Cu-Sn alloy layer is in contact with the contact or the like, it is exposed on the surface of the Cu-Sn alloy layer. Sn or Sn alloy is less likely to fray and is not easily affected by fretting. Also, Sn or Sn alloy dispersed in Cu and Cu-Sn alloy layers existing on the lower layer side of Cu-Sn alloy layer when left at high temperature Since there is room for the formation of a Cu—Sn alloy due to the reaction, CuO or the like is not formed on the surface, and the effect of stabilizing the contact resistance is also brought about.

  Although the thickness of the intermediate | middle layer 3 in the metal material 5 for connectors used for this invention is not specifically limited, 0.01-1.0 micrometer is preferable and 0.05-0.5 micrometer is more preferable.

  The connector metal material 5 used in the present invention is provided with the intermediate layer 3 made of copper or a copper alloy. However, the C layer 3a may disappear together with the S layer 4a after the heat treatment of the plated laminate 6. Even if it exists, the terminal insertion property of such a metal material etc. will hardly fall.

In the present invention, the outermost Cu—Sn alloy layer is preferably one in which the Cu concentration is gradually decreased from the substrate side toward the surface. In this case, the Cu—Sn alloy layer and the Cu layer below the Cu concentration are preferred. Alternatively, the boundary with the substrate is not clearly formed. In this case, when the boundary between the Cu-Sn alloy layer and the underlying Cu layer or the substrate is defined, the portion where the molar concentration of Sn or Cu exceeds 85% by cross-sectional observation by AES after FIB processing is It is regarded as a single layer of Sn or Cu. Conversely, when the molar concentration of Sn or Cu is 85% or less, it is regarded as a Cu—Sn alloy layer. Moreover, when forming an uneven layer without forming a flat layer, the thickness of three Cu—Sn alloy layers is measured by the above method, and the average value of the Cu—Sn alloy layer is measured. Consider it thick.
The Cu concentration distribution can be made into both a layered concentration distribution and a gradation concentration distribution depending on the manufacturing conditions, but gradation is preferable from the viewpoint of ease of manufacturing. In the present invention, the alloy composition of the entire Cu—Sn alloy layer defined as described above is preferably a Sn molar concentration of 15 to 85%, more preferably 25 to 75%.

  In the present invention, a metal material including a terminal contact portion that is a Cu-Sn alloy layer in which the Cu concentration is gradually reduced with the outermost surface facing the surface, and an electric wire crimping portion that has an Sn layer as the outermost surface. The metal material of this aspect can be manufactured by thinly plating the S layer at the location to be the terminal contact portion by masking or the like, and thickly plating the S layer at the location to be the wire crimping portion and heat-treating it. According to this method, it is possible to easily manufacture metal materials whose outermost surface materials are different for each part.

  When the heat treatment of the plated laminate 6 is performed by reflow treatment (continuous treatment), the actual temperature of the plated laminate 6 is preferably set to 232 to 500 ° C., and is 0.1 seconds to 10 minutes, more preferably 100 seconds or less. More preferably, it is applied by heating for 10 seconds or less. This reflow treatment is realized, for example, by maintaining the temperature in the reflow furnace at 500 ° C. to 900 ° C. and heating for 10 minutes or less, preferably 10 seconds or less. Actually, since the temperature in the reflow furnace is easier to measure than the temperature due to the actual temperature, it is desirable to perform the reflow process by managing the temperature in the reflow furnace. In addition, when applying by a batch process, the said laminated body is preferably applied in a 50-250 degreeC furnace, hold | maintaining for several tens minutes to several hours. Note that the temperature and heating time when the heat treatment is performed by reflow treatment must be set to conditions suitable for the thicknesses of the N layer 2a, C layer 3a, and S layer 4a of the plated laminate 6, which will be described later. As described in the embodiments, each specific condition can be set as appropriate.

  In the present invention, the conductive substrate 1 includes copper, phosphor bronze, brass, white, beryllium copper, Corson alloy and other copper alloys, iron, stainless steel having the electrical conductivity, mechanical strength and heat resistance required for the terminals. An iron alloy such as steel, a composite material such as a copper-coated iron material and a nickel-coated iron material, various nickel alloys and aluminum alloys are appropriately used.

  Of the metals and alloys (materials), copper-based materials such as copper and copper alloys are particularly suitable because of their excellent balance between conductivity and mechanical strength. In the case where the conductive substrate 1 is other than a copper-based material, the corrosion resistance and the adhesion with the underlayer 2 are improved by coating the surface with copper or a copper alloy.

  The base layer 2 that can be provided on the conductive substrate 1 as needed is a Ni, Co, or Fe metal having a barrier function for preventing the base component from thermally diffusing into the Cu-Sn alloy layer 4, or Ni alloys such as Ni-P, Ni-Sn, Co-P, Ni-Co, Ni-Co-P, Ni-Cu, Ni-Cr, Ni-Zn and Ni-Fe Fe alloy or Co alloy is preferably used. These metals and alloys have good plating processability and no problem in price. Among these, Ni and Ni alloys are recommended because the barrier function does not deteriorate even in a high temperature environment.

  Since the metal (alloy) such as Ni used for the underlayer 2 has a high melting point of 1000 ° C. or higher and the operating environment temperature of the connection connector is as low as 200 ° C. or less, the underlayer 2 itself hardly causes thermal diffusion, The barrier function is effectively expressed. The underlayer 2 also has a function of improving the adhesion between the conductive substrate 1 and the intermediate layer 3 depending on the material of the conductive substrate 1.

When the thickness of the underlayer 2 is less than 0.05 μm, the barrier function is not sufficiently exhibited, and when it exceeds 3 μm, the plating distortion increases and the base layer 2 is easily peeled off from the substrate. Therefore, 0.05 to 3 μm is desirable. The upper limit of the thickness of the underlayer 2 is preferably 1.5 μm, and more preferably 0.5 μm in consideration of terminal processability.
The underlayer 2 may be a single layer or two or more layers. In the case of two or more layers, there is an advantage that a barrier function, a function for improving adhesion, and the like can be appropriately set in relation to adjacent layers.

  In the present invention, the intermediate layer 3 can be made of copper alloy such as Cu—Sn based other than copper. The Cu concentration of the copper alloy is desirably 50% by mass or more.

  In the plated laminate 6 used in the present invention, when the S layer 4a is Sn and the C layer 3a is Cu, the volume ratio (S / C) between the S layer 4a and the C layer 3a is preferably 1.85 or less, The thickness of the S layer 4a is desirably 9.5 μm or less.

  The N layer 2a (Ni, etc.), the C layer 3a (Cu, etc.), the S layer 4a (Sn, etc.), etc. of the plating laminate 6 can be formed by PVD (Physical Vapor Deposition) method, etc., but the wet plating method is simple. Also desirable at low cost.

In the present invention, examples of the Cu—Sn intermetallic compound forming the Cu—Sn alloy layer 4 include Cu ₆ Sn ₅ , Cu ₃ Sn, and Cu ₄ Sn. Cu ₆ Sn ₅ is produced by reacting 1.90 volumes of Sn with 1 volume of Cu. Cu ₃ Sn is produced by reacting 0.76 volume of Sn with 1 volume of Cu. Cu ₄ Sn is produced by reacting 0.57 volume of Sn with 1 volume of Cu.

Therefore, when a plating laminate having a volume ratio (S / C) of the S layer 4a to the C layer 3a of, for example, 1.90 to 1.80 is heat-treated for a long time, a Cu—Sn alloy layer mainly composed of Cu ₆ Sn ₅ is formed. When a plating laminate having the volume ratio of, for example, 0.76 to 0.70 is heat-treated for a long time, a Cu—Sn alloy layer mainly composed of Cu ₃ Sn is formed, and the volume ratio is, for example, 0.57 to 0 When the .50 plated laminate is heat-treated for a long time, a Cu—Sn alloy layer mainly composed of Cu ₄ Sn is formed. Note that when the temperature of the heat treatment is high and the time of the heat treatment is short, these reactions are not performed completely, and the thickness of the Cu—Sn alloy layer becomes thin, or Cu ₆ Sn ₅ , Cu ₃ Sn. , Cu ₄ Sn may be formed as a mixed layer.

In the present invention, when the Cu—Sn alloy layer 4 is composed of two layers of a Cu ₆ Sn ₅ layer and a Cu ₃ Sn layer, the thickness of each layer is not particularly specified, but the Cu ₆ Sn ₅ layer is 0.01-5. The thickness of 0 μm and the Cu ₃ Sn layer is preferably 0.008 to 4.0 μm.

  Even if an oxide film having a thickness of 100 nm or less is formed on the surface of the Cu—Sn alloy layer 4, the connector metal material 5 used in the present invention does not adversely affect its performance. In the connector metal material 5 of the present invention, the outermost layer 4a before the heat treatment is made of Sn or Sn alloy, and in this case, an oxide of Sn is formed as an oxide. It is considered that the Sn oxide has higher conductivity than the Cu oxide and the like and does not adversely affect the conductivity as the metal material. The thickness of the oxide film is preferably 30 nm or less.

In the present invention, a dissimilar material thinner than the adjacent layers is interposed between the conductive substrate 1 and the underlayer 2, between the underlayer 2 and the intermediate layer 3, and between the intermediate layer 3 and the Cu—Sn alloy layer 4. Also good.
Moreover, the metal material used for the connector of the present invention may be provided with the Cu—Sn alloy layer 4 on the conductive substrate 1 or the Cu—Sn alloy layer on the underlayer 2 provided on the conductive substrate 1. 4 may be provided.
In the connector of the present invention, the low friction effect of the metal material and the synergistic effect of the low contact load design of the terminal enable further improvement of the insertion / removal that cannot be performed only by selecting the material, and stable electrical connection. Can also be maintained.

  Next, the present invention will be described in more detail on the basis of examples. However, for example, the sample and the production conditions thereof are only specific examples, and the present invention is not limited thereto.

Examples 1-24, Comparative Examples 1-12
A 0.20 mm thick brass strip is degreased and pickled in this order, and then the copper alloy strip is electroplated with Ni (Examples 21 to 24 only), Cu, and Sn in the following conditions to form a plated laminate Was made.

(Plating conditions)
[Ni plating]
Plating solution: Nickel sulfamate 500 g / liter
Boric acid 30 g / liter Plating condition: (Current density) 5 A / dm ² (Bath temperature) 60 ° C.
[Cu plating]
Plating solution: Copper sulfate 180g / liter
Sulfuric acid 80g / liter Plating condition: (Current density) 20A / dm ² (Bath temperature) 40 ° C
[Sn plating]
Plating solution: Sulfuric acid Sn 80g / liter
Sulfuric acid 80g / liter Plating condition: (Current density) 10A / dm ² (Bath temperature) 13 ° C

The volume ratio (S / C) of the S layer and the C layer of the produced plated laminate was varied in a range of 1/2 to 3/2. Next, the plating laminate was subjected to a reflow process (740 ° C., 7 seconds) to obtain a sample of a connector metal material. In addition, about the sample which has a dispersion | distribution pure Sn layer, compared with non-dispersion pure Sn, pure Sn thickness was thick, but it plated so that it might not remain as a layer, and pure Sn was disperse | distributed. In addition, for specimens used for male and female terminals with a pure Sn layer in the crimping part, during plating, the plating strips corresponding to the contact parts after masking are masked to correspond to the crimping part with the wire. By applying thinner Sn plating, a pure Sn layer was left in the crimped portion.
Subsequently, the heat-treated sample was press-cut to a width of 1 mm, and then molded as shown in FIG. The female terminal sample was press-molded so as to have various contact loads shown in Tables 1 and 2 by adjusting the tab gap, and a female terminal 20 as shown in FIG. 2 was produced. The displacement in the load measurement of the female terminal corresponds to a value obtained by subtracting the tab gap of the female terminal from the tab thickness of the male terminal. Therefore, when the tab thickness of the male terminal is determined, the tab gap of the female terminal having a desired contact load is determined. Therefore, a displacement-load graph (for example, FIG. 4) was created, and the tab gap of the female terminal was set so as to obtain a desired contact load.
The obtained sample was first prepared by an FIB (Focused Ion Beam) with a sample inclination of 60 degrees and an oblique section of 30 degrees to prepare an Auger measurement (AES) analysis sample, and further AES analysis was performed at 30 degrees. The sample was tilted and analyzed so that the oblique cross section was horizontal, an AES electron image was obtained, the thickness of each layer was measured, and the configurations are shown in Tables 1 and 2. In addition, about the Cu-Sn alloy layer of the outermost surface of the male terminal of Examples 1-24, and all the Cu-Sn alloy layers (in the sample of dispersion | distribution pure Sn layer thickness 0 micrometer, the mol of Sn in the whole Cu-Sn alloy layer) In samples where the concentration was about 20% and the balance was Cu, and the dispersed pure Sn layer thickness was more than 0 μm, the molar concentration of Sn in the entire Cu—Sn alloy layer was about 35% and the balance was Cu). Moreover, about the male terminal and female terminal of Examples 17-20, the outermost surface of a crimping | compression-bonding part is pure Sn, and only the outermost surface is a Cu-Sn alloy layer. On the other hand, what is described as “non-dispersed / pure Sn layer” in the comparative example of Table 2 is the pure Sn layer on the outermost surface, and the outermost surface in other cases is Cu—Sn having a thickness of 0.8 μm. Alloy layer (For samples with a dispersed pure Sn layer thickness of 0 μm, the Cu-Sn alloy layer has a molar concentration of Sn of about 20% and the balance is Cu, and for samples with a dispersed pure Sn layer thickness exceeding 0 μm, the Cu—Sn alloy layer The total molar concentration of Sn was about 35% and the balance was Cu).

(Fine sliding wear test)
The obtained sample was subjected to the following fine sliding wear test, and the change in the contact resistance value was continuously measured within 1000 reciprocations. The fine sliding wear test was performed as follows by the method shown in the schematic explanatory diagram of FIG.
That is, the male terminal 52 and the female terminal 51 are reciprocally slid at a sliding distance of 30 μm in an environment of a temperature of 20 ° C. and a humidity of 65%, and an open voltage of 20 mV is applied between both terminals from the power source 62 to make a constant current. 5 mA was passed, the voltage drop during sliding was measured with a voltmeter 61 by the 4-terminal method, the change in electrical resistance was determined every second, and evaluated according to the following criteria. As the mating material, a brass strip having a thickness of 0.25 mm was subjected to reflow Sn plating of 1 μm and then subjected to an overhanging process to 0.5 mmR. The measurement results of each coefficient of friction are shown in Tables 1 and 2.
X: Fretting peak occurs and its peak value is 10Ω or more ○: Fretting peak occurs and its peak value is 3Ω or more but less than 10Ω ◎: Fretting peak occurs and its peak value is less than 3Ω or Frette No peaking occurs

(Insertion force test)
Using the male terminal and the female terminal of this example and the comparative example, an insertion force test was performed by the method shown in the explanatory diagram of the schematic side view of FIG. That is, the female terminal 51 was fixed with the jig 53, and the male terminal 52 was inserted into the pressing jig 54 at a speed of 50 mm / min in the axial direction (the normal insertion direction of the terminal when the connector is fitted). The displacement-load curve at this time was monitored by the monitor 57 connected to the load cell 55 and the displacement meter 56, and the load peak value until the terminal reached the normal fitting position was recorded as the single terminal insertion force. The monitor 57 is shown in a perspective view for easy understanding. Each measurement was performed 5 times, and an average value was obtained and evaluated according to the following criteria. The results are shown in Tables 1 and 2.
◎: Insertion force is 0.5N or less ○: Insertion force exceeds 0.5N and 2.0N or less ×: Insertion force exceeds 2.0N

  As can be seen from a comparison between Table 1 and Table 2, in the connector of the comparative example, either the insertion force test or the fine sliding wear test is evaluated as x. ○ It has both insertion force and fretting prevention. It can be seen that the connector of this example has high electrical property reliability while having a low insertion force terminal.

Examples 25-32
A male terminal and a female terminal were prepared in the same manner as in Examples 1 to 16 except that the dispersion pure Sn thickness of the terminal contact portion and the Cu-Sn thickness of the outermost surface were shown in Table 3, and the insertion force test, fine sliding A dynamic wear test was performed. In Example 25 in which the dispersed pure Sn layer thickness is 0 μm, the molar concentration of Sn in the entire outermost Cu—Sn alloy layer is about 20%, the balance being Cu, and the thickness of the dispersed pure Sn layer exceeding 0 μm in Examples 26 to 32 Then, the molar concentration of Sn in the entire Cu—Sn alloy layer was about 35%, and the balance was Cu. The test results are also shown in Table 3.

  As shown in Table 3, all the evaluations are ◯, and it can be seen that the connector of this example can achieve both insertion force and fretting prevention.

DESCRIPTION OF SYMBOLS 1 Conductive base | substrate 2 Base layer which consists of Ni etc. 2a Ni layer (N layer)
3 Intermediate layer made of copper, etc. 3a Cu layer (C layer)
4 Cu-Sn alloy layer 4a Sn layer (S layer)
4b Cu-Sn intermetallic compound 4c Sn or Sn alloy 5 Metal material 6 Plating laminate 10 Male terminal 11 Tab 12 Wire barrel 20 Female terminal 21 Tongue piece 22 Dimple 23 Bead 31 Surface of outermost layer 32 Base body 33 Underlayer 34 Intermediate layer 35 Outermost layer 36 Sn or Sn alloy 51 Female terminal 52 Male terminal 53 Jig 54 Push jig 55 Load cell 56 Displacement meter 57 Monitor 61 Power supply 62 Voltmeter

Claims (8)

  A male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6N or more and 6.0N or less are configured to be connectable to each other, and the male terminal and the female terminal A connector, wherein at least one outermost surface is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.   2. The connector according to claim 1, wherein the outermost surface of the male terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.   A male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6N or more and 6.0N or less are configured to be connectable to each other, and the male terminal and the female terminal A connector, wherein the outermost surface of at least one contact portion is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.   4. The connector according to claim 3, wherein an outermost surface of a contact portion of the male terminal is formed of a metal material that is a Cu—Sn alloy layer having a thickness of 0.10 μm to 3.0 μm.   A male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6N or more and 6.0N or less are configured to be connectable to each other, and the male terminal and the female terminal At least one outermost surface is a Cu—Sn alloy layer including a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and a thickness of the dispersed pure Sn layer or more. A connector formed of a metal material.   The outermost surface of the male terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, and is a Cu—Sn alloy layer having a thickness of 0.10 μm or more and 3.0 μm or less and a thickness of the dispersed pure Sn layer or more. The connector according to claim 5, wherein the connector is made of a certain metal material.   A male connector having a male terminal and a female connector having a female terminal having a contact load of 0.6N or more and 6.0N or less are configured to be connectable to each other, and the male terminal and the female terminal The outermost surface of at least one contact portion includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and a Cu—Sn alloy having a thickness of the dispersed pure Sn layer or more. A connector characterized by being formed of a metal material as a layer.   The outermost surface of the contact portion of the male terminal includes a dispersed pure Sn layer having a maximum thickness of 0.01 μm or more and 0.50 μm or less, a thickness of 0.10 μm or more and 3.0 μm or less, and Cu—Sn having a thickness of the dispersed pure Sn layer or more. The connector according to claim 7, wherein the connector is made of a metal material that is an alloy layer.