JP2009026500A - Conductive member, terminal, method for producing conductive member, and method for producing terminal - Google Patents

Abstract

In particular, a conductive member capable of maintaining a low contact resistance for a long period of time without requiring an expensive material such as a precious metal and suppressing fine sliding wear, and a terminal using the conductive member Furthermore, it aims at providing the manufacturing method which can manufacture this electrically-conductive member and a terminal easily.
A conductive member having a contact portion in contact with another conductor, electrically connected to the other conductor by contact with the other conductor, and comprising a base material made of a copper-based material; And a conductive film disposed at least on the contact part of the surface of the base material, wherein the conductive film is made of a compound containing copper and gallium.
[Selection] Figure 1

Description

  The present invention relates to a conductive member used for an electrical connection terminal or the like, a terminal using the conductive member, and a method for manufacturing the same.

  As the base material of the conductive member used for the electrical connection terminal or the like, copper (Cu) having high conductivity, high ductility, and appropriate strength is preferably used. However, a copper-based substrate containing copper has an insulating film such as an oxide film or a sulfide film formed on its surface, which increases the contact resistance (boundary resistance) at the time of contact with another conductor. . The resistance value varies depending on, for example, the material and the use environment, but may reach several ohms, which may cause malfunction of the electric circuit.

  Therefore, as the conductive member, a material obtained by performing tin plating on the surface of the copper base material is used. Since tin has a lower hardness than other metals, even if the tin is oxidized to form an insulating film, the insulating film is broken with a relatively weak force. Therefore, the conductive member subjected to tin plating can easily break the insulating film, and can ensure a good electrical connection by exposing the new surface.

On the other hand, as another material mainly composed of a copper-based material, for example, a copper-based material is used as a base material. Examples thereof include electrical contact materials in which compound particles are dispersed (see Patent Document 1).
JP 58-128609 A

  As described above, the conductive member subjected to tin plating can be brought into contact with another conductor on the surface and applied with a load to reduce the contact resistance with the other conductor. However, a tin-plated conductive member is subject to the presence of tin oxide present on the surface of the conductive member when it is slightly slid due to vibration or temperature change with a load applied by contact with another conductor on its surface. As the amount increases, a so-called fretting corrosion phenomenon occurs in which the contact resistance with other conductors increases. Fine sliding wear is a contact that comes into contact with other conductors by repeated oxidation of tin on the surface of the new surface, which is caused by peeling the oxide film on the surface of the tin plating by sliding and exposing the tin surface to the atmosphere. This is a phenomenon in which a large amount of tin oxide is deposited in the vicinity of a portion, and the contact portion rides on this large amount of oxide, whereby the contact resistance with other conductors is increased (for example, by R. S. Mroczkowski, “ "Electronic Connector Handbook", p. 3.31-3.38). This fine sliding wear may cause the contact resistance to exceed 1Ω.

  Moreover, the conductive member which gave such tin plating is used for the terminal etc. of a connector, for example. A connector is generally configured so that a male terminal and a female terminal are fitted to each other. When the male terminal is inserted into (inserted into) the female terminal, a load is applied to the male terminal by the spring force of the female terminal. Thus, the metal parts (contact parts) of both terminals are configured to contact each other. At that time, the spring force of the female terminal is actually made stronger than the force that can break the insulating film so as not to cause a malfunction, although the insulating film formed on the tin surface is likely to be broken. It is configured. Such a strong spring force not only makes it difficult to design and manufacture the connector, but also increases the frictional force applied to the contact area during insertion, so it is particularly difficult to perform a fitting operation in a multipolar connector in which a large number of terminals are integrated. become. Furthermore, since a thick oxide film or the like is formed in a harsh use environment such as a high temperature and high humidity state, it is difficult to keep the contact resistance low for a long period of time.

  In order to prevent the occurrence of fine sliding wear, it is conceivable to plate the surface of the contact portion of the terminal with a noble metal such as gold, platinum and palladium that is not oxidized in the atmosphere. However, since noble metals such as gold, platinum, and palladium are more expensive than tin, the price of the conductive member itself is increased.

  Further, Patent Document 1 discloses only a material mainly composed of copper that has high durability such as resistance to oxidation and is difficult to wear, and suppresses fine sliding wear without requiring a precious metal. The technology to do is not disclosed.

  The present invention has been made to solve such conventional problems, and in particular, it can maintain a low contact resistance for a long period of time without requiring an expensive material such as a noble metal, It is an object of the present invention to provide a conductive member capable of suppressing sliding wear and a terminal using the conductive member, and to provide a manufacturing method capable of easily manufacturing the conductive member and the terminal.

  The conductive member of the present invention is a conductive member that has a contact portion that comes into contact with another conductor and is electrically connected to the other conductor by contact with the other conductor, and is made of a copper-based material. A conductive member comprising: a base material; and a conductive film disposed at least on the contact portion of the surface of the base material, wherein the conductive film is made of a compound containing copper and gallium.

  According to this configuration, since the compound containing copper and gallium is chemically stable, the conductive film made of the compound containing copper and gallium has an oxide film formed on the surface of the tin film. It is very thin compared to the oxide film formed on the surface. Therefore, the conductive film made of a compound containing copper and gallium is easily destroyed by simply applying a relatively low load to the surface, and the destruction of the oxide film A new surface having conductivity is exposed. Therefore, the conductive member in which the conductive film is disposed at the contact site can ensure good electrical connection with other conductors.

  Furthermore, this conductive film is thin, for example, even when the conductive member is exposed to a high temperature in the atmosphere, such as being exposed to high temperatures, the surface oxidation is suppressed, and the thickness of the oxide film hardly changes. It remains. Therefore, a conductive film made of a compound containing copper and gallium exposes a new conductive surface only by applying a relatively low load to the surface even in a harsh environment.

  From the above, even if the load applied to the conductive film is relatively low, low contact resistance can be maintained. In addition, the conductive member suppresses the deposition of oxide on the conductive film even when the conductive member slides slightly due to vibration or temperature change of the conductive member. Therefore, this conductive member can maintain a low contact resistance for a long time without requiring an expensive material such as a noble metal, and can suppress fine sliding wear.

Further, the conductive film is preferably made of at least one of CuGa ₂ and _Cu 9 Ga _4.

  Moreover, it is preferable that the said electroconductive film is formed by apply | coating the metal of the liquid state containing a gallium to the surface of the said base material. According to this configuration, the conductive film formed on the surface of the base material is a film made of a compound containing copper and gallium, and the film is thin and uniform.

  Further, the present invention is a terminal that has a contact portion that comes into contact with a counterpart terminal, contacts the counterpart terminal by fitting with the counterpart terminal, and is electrically connected to the counterpart terminal, at least A portion including the contact portion is made of the conductive member.

  According to this configuration, the oxide film formed on the surface of the conductive film disposed on the contact portion in contact with the counterpart terminal can be easily formed by simply contacting the counterpart terminal with a relatively low load. Therefore, the contact resistance can be kept low even if the spring force for press-contacting the terminal and the counterpart terminal is weakened when the terminal is fitted. In addition, since this terminal suppresses the accumulation of oxide on the conductive film even when the terminal slides slightly due to vibration, temperature change, etc., it is particularly expensive material such as noble metal. Therefore, the contact resistance can be kept low for a long period of time and fine sliding wear can be suppressed.

  Further, since the terminal is often used while being fitted to the counterpart terminal and in contact with the counterpart terminal, there is a high possibility that the terminal and the counterpart terminal slide slightly. Therefore, it is particularly preferable to use the conductive member of the present invention capable of suppressing fine sliding wear for the terminal.

  Furthermore, the conductive film disposed at the contact site can weaken the spring force because the oxide film formed on the surface is easily broken only by applying a relatively low load to the surface. Therefore, the frictional force applied to the terminal and the counterpart terminal during insertion can be reduced, and the insertion becomes easy.

  Moreover, the manufacturing method of the electrically-conductive member of this invention is a manufacturing method of the electrically-conductive member which has a contact part which contacts another conductor, and is electrically connected with the said other conductor by contact with the said other conductor. A conductive member comprising a film forming step of forming a conductive film by applying a liquid metal containing gallium to at least the surface of the contact portion of a base material made of a copper-based material. It is a manufacturing method.

  According to this configuration, a conductive film containing a compound of copper and gallium can be thinly and uniformly formed on the surface of the substrate by applying a liquid metal containing gallium to the surface of the substrate. A conductive member that can maintain a low contact resistance for a long period of time and can suppress fine sliding wear can be easily manufactured.

  That is, when a metal in a liquid state containing gallium is brought into contact with a copper base material, a conductive film containing a compound of copper and gallium is formed. This is considered to be because the formation of a new conductive film is inhibited.

  Moreover, it is preferable that the said film formation process includes the metal removal process of removing an excess metal, after apply | coating the said metal of the liquid state. According to this configuration, it is not necessary to strictly control the amount of liquid metal applied to the surface of the substrate by removing excess metal. Moreover, it can prevent that a metal in a liquid state contacts other than a predetermined | prescribed location by excess metal dripping down or flowing other than a predetermined | prescribed location.

  Further, it is preferable to apply a metal having a melting point of 25 ° C. or less as the metal. According to this configuration, since the metal containing gallium is in a liquid state at room temperature in the film forming step, the metal containing gallium does not need to be heated in advance, so that a conductive member can be manufactured more easily. it can.

  Moreover, since it is not necessary to heat and melt the metal containing gallium in the liquid state, the manufacturing apparatus for manufacturing the conductive member does not need a heating apparatus for heating the metal, and the apparatus is complicated. You don't have to.

  Moreover, it is preferable that the metal further includes at least one selected from the group consisting of tin, indium, and zinc. When these metals are contained, the melting point of the metal is lowered, so that heating for bringing the metal containing gallium into a liquid state is unnecessary, or even if necessary, the time for the heating is short. Tesumu. Furthermore, since any of tin, indium, and zinc does not react with copper, the same conductive film as that obtained when gallium melt is used as the metal is obtained, and the contact resistance is kept low for a long time. And fine sliding wear can be suppressed.

  Moreover, the manufacturing method of the terminal of this invention is a manufacturing method of the terminal which has a contact part which contacts a counterpart terminal, and manufactures the part containing the said contact part with the manufacturing method of the said electrically-conductive member. . According to this configuration, it is possible to easily manufacture a terminal that can maintain a low contact resistance for a long period of time and can suppress fine sliding wear.

  According to the present invention, in particular, without requiring an expensive material such as a noble metal, a conductive member that can maintain a low contact resistance for a long period of time and can suppress fine sliding wear, and this conductive member The used terminal can be provided, and further, a manufacturing method capable of easily manufacturing the conductive member and the terminal can be provided.

  An example of a terminal according to an embodiment of the present invention will be described. Here, a terminal pair in which a male terminal and a female terminal can be fitted, and the terminal pair in the case where the male member and the female terminal are terminals using the conductive member of the present invention is taken as an example. However, the terminal using the conductive member of the present invention may be used only for either the male terminal or the female terminal.

  FIG. 1 is a schematic cross-sectional view showing a terminal pair 10 composed of terminals according to an embodiment of the present invention. The terminal pair 10 includes a male terminal 11 and a female terminal 21. FIG. 1 shows a fitting state in which the male terminal 11 and the female terminal 21 of the terminal pair 10 are fitted.

  The male terminal 11 includes an insertion portion 12 and an unillustrated wire connection portion to which the end of the covered wire is connected. The male terminal 11 is a member that is inserted (inserted) into the female terminal 21 that is a counterpart terminal. The shape of the insertion portion 12 is not particularly limited as long as it can be inserted (inserted) into the female terminal 21, and can be appropriately selected from various shapes such as a plate shape, a rod shape, and a cylindrical shape.

  The female terminal 21 has an unillustrated wire connection in which a terminal fitting portion 22 into which the insertion portion 12 is inserted (inserted) and a terminal of a covered wire different from the covered wire connected to the male terminal 11 are connected. A part.

  The terminal fitting portion 22 is a female type and includes a cylindrical portion 23 and a spring piece 24. The cylindrical portion 23 is formed in a rectangular tube shape having an open front end so that the male terminal 11, which is the counterpart terminal of the female terminal 21, can be inserted (inserted) along the insertion direction, and the ceiling wall 25 ( 1 is provided with a bottom wall 26 (a bottom surface in FIG. 1) and a side wall (not shown).

  The spring piece 24 is inclined toward the inner side of the tubular portion 23 toward the direction close to the ceiling wall 25 (obliquely upward in FIG. 1), and rearward from the opening tip (tip of the bottom wall 26) of the tubular portion 23. It extends in a cantilevered direction. And it extends toward the front from the bent part 24a through the bent part 24a bent downward in the U-shape at the rear end, and inclined toward the direction close to the bottom wall 26 (obliquely downward in FIG. 1). Furthermore, it is a free end that bends in the vicinity of the bottom wall 26 and is inclined toward the direction of approaching the ceiling wall 25. Further, the spring piece 24 is formed with a convex portion 24 b between the opening tip of the cylindrical portion 23 and the bent portion 24 a in a direction approaching the ceiling wall 25. With this configuration, when the insertion portion 12 of the male terminal 11 is inserted into the terminal fitting portion 22, the insertion portion 12 and the convex portion 24 b of the spring piece 24 come into contact with each other, and the spring piece 24 is elastically deformed so that the convex portion 24b sinks downward. Due to the elastic force based on the elastic deformation of the spring piece 24, the insertion portion 12 is pressed upward by the spring piece 24. As a result, the insertion portion 12 is held between the ceiling wall 25 and the convex portion 24b of the spring piece 24, and electrical connection is made.

  Next, the configuration of the male terminal 11 and the female terminal 21 will be described.

  The male terminal 11 and the female terminal 21 include a copper base material and a conductive film. In the case of the male terminal 11, the conductive film has a position that contacts the convex portion 24 b of the spring piece 24 and a position (contact portion) that contacts the ceiling wall 25 when the male terminal 11 and the female terminal 21 are fitted. It is arranged in the part including. Further, in the case of the female terminal 21, the conductive coating is disposed at a portion including a position (contact portion) that contacts the insertion portion 12 of the male terminal 11 when the male terminal 11 and the female terminal 21 are fitted. Yes. Accordingly, the male terminal 11 and the female terminal 21 are provided with a conductive film, which will be described later, at least in a portion including the contact portion. The terminal pair 10 shown in FIG. Electrical contact is made by contact with the conductive film, and electricity can be applied. In addition, the conductive film should just be arrange | positioned in the part containing a contact site | part at least, and may coat | cover the whole surface of the male terminal 11 and the female terminal 21. FIG.

  The said copper-type base material should just consist of a copper-type material which contains copper as a main component, for example, may consist of a copper simple substance, and may consist of a copper alloy. Examples of components other than copper include iron, silicon, zinc, magnesium, nickel, chromium, cobalt, molybdenum, tin, phosphorus, and aluminum. Examples of the copper alloy include phosphor bronze containing tin and phosphorus, brass containing zinc, and the like.

The conductive film is a film made of a compound containing copper and gallium. The compound containing copper and gallium is preferably a compound composed of copper and gallium, and specific examples include CuGa ₂ and Cu ₉ Ga ₄ . Therefore, the conductive film is preferably made of at least one of CuGa ₂ and _Cu 9 Ga _4.

Moreover, it is preferable that a conductive film is formed by apply | coating the metal of the liquid state containing a gallium to the surface of a copper-type base material. The conductive film thus formed can be formed thin and uniformly. Further, this conductive film is made of a compound containing copper and gallium, and CuGa ₂ is estimated to be a main component by X-ray diffraction or the like.

  The thickness of the conductive film is not particularly limited, but is preferably 0.1 to 5 μm. If the conductive film is too thin, it is difficult to form a uniform film, and there is a tendency to form a portion where the copper base material is exposed. If it is too thick, the conductive film is less conductive than the copper base material, and contact is caused. There is a tendency for resistance to increase. Also, when trying to increase the thickness of the conductive film, the time during which the liquid metal is brought into contact with the copper-based substrate (processing time) becomes longer, or the liquid metal droops from the copper-based substrate during manufacturing. There is a tendency for problems to occur due to falling.

  When formed by contact with a liquid metal containing gallium, a thin and uniform conductive film having a suitable thickness of about 1 μm can be formed by contact for several minutes without special control. This is because when a metal in a liquid state containing gallium is brought into contact with a copper base material, a conductive film made of a compound of copper and gallium is formed. This is considered to be because the formation of a new conductive film is inhibited.

  Next, the manufacturing method of the male terminal 11 and the female terminal 21 is demonstrated.

  First, an insulating film such as an oxide film formed on the surface of the copper base material is removed by polishing or acid cleaning. Next, this copper base material is processed into a predetermined shape by pressing or the like. In addition, this shape processing may be performed on the copper base material from which the insulating film has not been removed, and the insulating film may be removed after the shape processing.

  And the metal of the liquid state containing a gallium is apply | coated to the surface of the obtained copper-type base material. By doing so, a conductive film made of a compound containing copper and gallium is formed on the surface of the copper-based substrate. It is preferable that the formation process which forms this membrane | film | coat is a process of apply | coating the said metal to the surface of a copper-type base material. Moreover, a conductive film may be formed before the shape processing, and then the shape processing may be performed.

  The metal contains gallium and may be in a liquid state when applied to the surface of the copper-based substrate. For example, the metal may be gallium alone or a gallium alloy. When gallium alone is used as the metal, the melting point of gallium is 29.7 ° C., so it is necessary to obtain a gallium melt obtained by heating.

  As the gallium alloy, a Ga—In alloy containing Ga and In is preferable, and an alloy further containing Sn is more preferable. As a specific example of the gallium alloy, for example, an alloy composed of Ga 60 to 80% by mass, In 10 to 30% by mass, and Sn 5 to 20% by mass is preferable. More specific examples of the gallium alloy include, for example, an alloy composed of 62.5 mass% Ga, 21.5 mass% In, 16 mass% Sn (melting point 10.7 ° C), 62 mass% Ga, 25 mass% In, and 13 mass% Sn. Alloy (melting point 10.6 ° C.), Ga 62 mass%, In 23 mass%, Sn 13 mass%, alloy consisting of Zn 2 mass% (melting point 9.8 ° C.), etc., among these, Ga 62.5 mass% An alloy (melting point: 10.7 ° C.) composed of 21.5 mass% In and 16 mass% Sn is more preferable.

  Examples of preferable components other than the metal gallium include tin (Sn), indium (In), and zinc (Zn). Since these metals do not react with copper or penetrate into the copper base material, even if these components are contained, the same conductivity as when gallium melt is used as the metal. A film can be formed. In addition, when these metals are contained, the melting point of the metal is lowered, so that heating for bringing the metal containing gallium into a liquid state is unnecessary, or even if necessary, the time for the heating. Is short.

  In addition, the component contained in addition to the metal gallium is not limited to the above component, and does not react with copper or enter the copper-based substrate, and has the same conductivity as when gallium melt is used. Any film that can form a film may be used.

  Further, the melting point of the metal is preferably 25 ° C. or less, and more preferably 10 ° C. or less. If the melting point is higher than room temperature, it is necessary to heat the metal containing gallium to a liquid state at the time of manufacture, and if the melting point is too high, the time for the heating becomes longer. It takes time to manufacture.

  The method for applying the metal in the liquid state is not particularly limited, and any application method can be adopted. For example, a dipping method, a spin coating method, a spray method, a roller method, a printing method such as screen printing, a roll coater method, a curtain flow coater method, a brush coating method, and the like can be given. Moreover, although the said metal may be apply | coated to the whole surface of a copper-type base material, what is necessary is just to apply | coat partially to a contact location at least.

  Since the contact time (treatment time) between the copper base material and the metal in the liquid state is 1 minute to 1 hour in any of a wide range, the thickness of the conductive film to be formed hardly changes. Although it is not necessary to strictly control the treatment time, it is preferably 1 to 15 minutes. By doing so, the conductive film is reliably formed, and the manufacturing efficiency is high. In addition, the treatment temperature when the copper base material and the liquid metal are in contact with each other is not particularly limited, and is preferably 10 to 130 ° C.

  Moreover, it is preferable that the said film formation process includes the metal removal process of removing an excessive metal, after apply | coating the metal of a liquid state. As a metal removal process, the process of wiping off excess metal with a cotton swab, paper waste, a nonwoven fabric, etc., the process of spraying a high pressure gas or a liquid agent, etc. are mentioned, for example.

  As mentioned above, although the terminal which concerns on embodiment of this invention was demonstrated, the electrically-conductive member of this invention is not restricted to the case where it is used for a terminal, has a contact part which contacts another conductor, and contacts with the said other conductor As long as the conductive member is electrically connected to the other conductor. For example, it can be applied to a contact portion of a normally closed switch. However, since the terminal is often used in a state in which the terminal is fitted to the counterpart terminal and is in contact with the counterpart terminal, there is a high possibility that the terminal and the counterpart terminal slide slightly. Therefore, it is particularly preferable to use the conductive member of the present invention capable of suppressing fine sliding wear for the terminal.

  Hereinafter, the present invention will be described with reference to examples.

Example 1
In Example 1, an electrical connection structure 30 as shown in FIG. 2 was manufactured and evaluated as described later. FIG. 2 is a schematic cross-sectional view of the electrical connection structure 30 using the conductive member according to the embodiment. The electrical connection structure 30 shown in FIG. 2 is composed of a pair of conductive members of a first conductive member 31 and a second conductive member 32. The first conductive member 31 and the second conductive member 32 were manufactured as follows.

  First, a phosphor bronze plate (copper base material) 35 on which an insulating film such as an oxide film was not formed was prepared. The phosphor bronze plate 35 was pressed to form a hemispherical convex portion 33 having a diameter of 1 mm. The phosphor bronze plate subjected to press working was immersed in a gallium melt melted by heating to 50 ° C. for about 1 minute, and then taken out from the gallium melt. Then, the unreacted gallium melt adhering to the surface was wiped off with a nonwoven fabric, and the surface was washed with dilute hydrochloric acid to remove the gallium melt on the surface of the phosphor bronze plate. By doing so, the 1st electroconductive member 31 in which the electroconductive film | membrane 36 was formed on the surface of the copper-type base material 35 was obtained.

  Moreover, the 2nd electroconductive member 32 by which the electroconductive film | membrane 36 was formed on the surface of the copper-type base material 35 was obtained by the process similar to the above using the phosphor bronze board 35 which did not perform the press work prepared separately. .

  Then, the two obtained conductive members (the first conductive member 31 and the second conductive member 32) were opposed to each other as shown in FIG. By doing so, the electrical connection structure 30 was obtained.

  Note that the portion of the convex portion 33 of the first conductive member 31 that contacts the second conductive member 32 is the contact portion (contact point) of the first conductive member 31, and the first portion that contacts the convex portion 33 of the first conductive member 31. The part of the second conductive member 32 is a contact part (contact point) of the second conductive member 32. As shown in FIG. 2, the conductive film 36 is disposed at least at the contact site. The first conductive member 31 corresponds to another conductor for the second conductive member 32, and the second conductive member 32 corresponds to another conductor for the first conductive member 31. That is, the first conductive member 31 and the second conductive member 32 correspond to conductive members, respectively, and correspond to other conductors of the counterpart member.

  When the conductive members (first conductive member 31 and second conductive member 32) of Example 1 were sliced in the vertical direction and observed with a scanning electron microscope, the thickness of the conductive film 16 was about 0.6 μm. It was flat.

(Example 2)
In Example 2, instead of immersing the phosphor bronze plate in the gallium melt for about 1 minute, an alloy composed of 62.5% by mass of Ga, 21.5% by mass of In and 16% by mass of Sn was applied to the phosphor bronze plate at room temperature. And it is the same as that of Example 1 except hold | maintaining for 1 minute.

  When the conductive member of Example 2 was sliced in the vertical direction and observed with a scanning electron microscope, the conductive film had a thickness of 0.2 to 0.4 μm and was flat. In addition, when the surface of the conductive member of Example 2 was measured using an energy dispersive X-ray fluorescence spectrometer (EDX), In and Sn were not detected, and the conductive film was a compound layer of copper and gallium. I found out.

(Comparative Example 1)
Comparative Example 1 is the same as Example 1 except that a conventional conductive material in which tin plating with a thickness of 1 μm is formed on the surface of a phosphor bronze plate is used.

(Comparative Example 2)
Comparative Example 2 is the same as Example 1 except that an untreated phosphor bronze plate was used.

  The above Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated as follows.

(Slight sliding wear)
The two conductive members obtained in Example 1 were opposed to each other as shown in FIG. 2, and one of the conductive members was slid in the horizontal direction while measuring the contact resistance with a load applied. The conductive member of Comparative Example 1 was measured in the same manner. The result is shown in FIG.

  FIG. 3 is a graph showing evaluation results of fine sliding wear. The vertical axis represents contact resistance (mΩ), and the horizontal axis represents the number of sliding times. Further, the broken line 41 indicates Example 1, and the broken line 42 indicates Comparative Example 1.

  As shown in FIG. 3, in Example 1, the contact resistance hardly increases regardless of the number of sliding times and is maintained at 10 mΩ or less, whereas in Comparative Example 1, the sliding number is around 100 times. The contact resistance increased and increased to near 1Ω.

  As a result, the conventional conductive member plated with tin was subjected to fine sliding wear, but in the example provided with the conductive film made of a compound of copper and gallium, the fine sliding wear was suppressed. I understand that.

(Resistance increase after leaving at high temperature 1)
The two conductive members obtained in Example 1 were made to face each other as shown in FIG. 2, and the contact resistance was measured in a state where a load was applied. After that, the conductive members were heat-treated at 160 ° C. for 300 hours. Again, contact resistance was measured. Further, Comparative Example 1 was measured in the same manner.

  As a result, in Example 1, the contact resistance hardly changed even after the heat treatment, whereas in Comparative Example 1, the contact resistance value after the heat treatment was about 10 times that before the heat treatment.

(Resistance increase after standing at high temperature 2)
The two conductive members obtained in Example 2 were heat-treated at 180 ° C. for 4 hours, then faced as shown in FIG. 2, and the contact resistance was measured with a load applied. Further, Comparative Example 2 was measured in the same manner.

  As a result, the contact resistance value of Example 1 was as low as about 10 mΩ, whereas the contact resistance value of Comparative Example 2 exceeded 1Ω and was very high.

  From the results of the resistance increase 1 after standing at high temperature and the resistance increase 2 after standing at high temperature, the embodiment provided with the conductive film made of a compound of copper and gallium is not limited to fine sliding wear. It can be seen that the conductive member has high temperature storage stability.

(Oxide film thickness)
After the conductive member obtained in Example 1 was heat-treated at 160 ° C. for 300 hours, the thickness of the oxide film was measured by X-ray photoelectron spectroscopy (XPS). Further, Comparative Example 2 was measured in the same manner.

  As a result, the thickness of the oxide film of Example 1 was 6 nm or less without much change from that before the heat treatment, whereas the thickness of the oxide film of Comparative Example 2 was about 150 nm.

  Therefore, in the example provided with the conductive film made of a compound of copper and gallium, the oxide film is thin even when heat-treated, so that the contact resistance is kept low, and the oxide film is thick even by sliding. It is thought that resistance does not increase.

It is a schematic sectional drawing which shows the terminal pair 10 which consists of a terminal which concerns on embodiment of this invention. The schematic sectional drawing of the electrical connection structure 30 using the electrically-conductive member which concerns on an Example is shown. It is a graph which shows the evaluation result of fine sliding wear.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Terminal pair 11 Male terminal 12 Insertion part 21 Female terminal 22 Terminal fitting part 23 Cylindrical part 24 Spring piece 24a Bending part 24b Protrusion part 25 Ceiling wall 26 Bottom wall 30 Electrical connection structure 31 1st conductive member 32 2nd conductive member 33 Convex part 35 Copper base material 36 Conductive film

Claims (9)

A conductive member having a contact portion that contacts another conductor, and electrically connected to the other conductor by contact with the other conductor;
A base material made of a copper-based material;
A conductive film disposed at least on the contact portion of the surface of the substrate;
The conductive member is made of a compound containing copper and gallium. The conductive member according to claim 1, wherein the conductive film is made of at least one of CuGa ₂ and Cu ₉ Ga ₄ .   The conductive member according to claim 1, wherein the conductive film is formed by applying a liquid metal containing gallium to the surface of the base material. It has a contact portion that comes into contact with a counterpart terminal, and is a terminal that comes into contact with the counterpart terminal by fitting with the counterpart terminal and is electrically connected to the counterpart terminal,
The terminal including at least the portion including the contact portion is made of the conductive member according to claim 1. A method for producing a conductive member having a contact portion that contacts another conductor, and being electrically connected to the other conductor by contact with the other conductor,
A method for producing a conductive member comprising a film forming step of forming a conductive film by applying a liquid metal containing gallium to at least the surface of the contact portion of a base material made of a copper-based material .   The said film formation process is a manufacturing method of the electrically-conductive member of Claim 5 including the metal removal process of removing an excessive metal, after apply | coating the said metal of the liquid state.   The manufacturing method of the electrically-conductive member of Claim 5 or Claim 6 which apply | coats what has melting | fusing point of 25 degrees C or less as said metal.   The method for producing a conductive member according to claim 7, wherein the metal further includes at least one selected from the group consisting of tin, indium, and zinc. A method of manufacturing a terminal that has a contact portion that contacts a counterpart terminal, contacts the counterpart terminal by fitting with the counterpart terminal, and is electrically connected to the counterpart terminal,
A method for manufacturing a terminal, wherein a portion including at least the contact part is manufactured by the method for manufacturing a conductive member according to any one of claims 5 to 8.

Images