TW201526054A - Electrical contact structure comprising movable contact part and fixed contact part - Google Patents

Abstract

An electrical contact structure having a movable contact part and a fixed contact part, wherein: the movable contact part is configured from a movable contact part member having a movable contact part base layer comprising nickel, cobalt, a nickel alloy, or a cobalt alloy on at least a part of the surface of an electroconductive substrate, with a movable contact part surface layer comprising silver or a silver alloy being formed on the movable contact part member; and the fixed contact part is configured from a fixed contact part member having a fixed contact part base layer comprising copper or a copper alloy on the substrate, with a fixed contact part outermost surface layer comprising nickel, tin, zinc, a nickel alloy, a tin alloy, or a zinc alloy being formed on the fixed contact part base layer.

Description

Electrical contact structure composed of movable contact portion and fixed contact portion

The present invention relates to an electrical contact structure composed of a movable contact portion and a fixed contact portion.

Previously, push button switches for mobile phones or portable terminal machines, even remote control switches or composite printers used phosphor bronze or beryllium copper on the movable contact side, and Corson copper alloys in recent years. A conductive substrate having excellent elasticity such as a copper alloy or an iron-based alloy such as stainless steel is plated. Specifically, the nickel film material obtained by performing nickel plating on the conductive substrate and the silver film material obtained by performing nickel plating on the conductive substrate and then silver plating on the outermost layer are provided.

On the other hand, a material obtained by gold plating the outermost layer on the resin substrate is usually used on the fixed contact side. The material is based on a resin substrate material, for example, a copper substrate is bonded to an epoxy substrate woven into a glass fiber to form a copper base layer, and a nickel layer is formed on the surface of the copper base layer as an intermediate layer. A gold-coated film layer having excellent conductivity is formed on the surface of the nickel intermediate layer.

In recent years, in order to reduce the cost of contact parts for precision machines such as mobile phones, there is a tendency to apply a technique using the following contacts: a gold film printing base is used on the fixed contact side. Plate, nickel plated film is used on the movable contact side. However, a printed substrate on which a copper film layer is formed on a resin substrate is often used on the fixed contact side. Therefore, in order to achieve good conductivity, a film layer of gold or a gold alloy is often formed on the outermost layer of the above printed substrate.

Further, as in Patent Document 1 below, a silver plating layer is formed on the side of the fixed contact portion.

[Patent Document 1] Japanese Laid-Open Patent Publication No. 2011-127225

However, in the conventional fixed contact portion having a film layer of gold or a gold alloy in the outermost layer, the thickness of the gold layer is extremely thin in order to achieve low cost. Therefore, it is understood that pinholes are likely to occur in the electrical contact portions of the switches, and corrosion resistance is not sufficient. Specifically, there is a problem of insufficient environmental resistance. That is, there is a problem that if a high temperature atmosphere or a high temperature and high humidity environment causes corrosion from the base layer, the contact resistance increases and the contact characteristics deteriorate. Further, since the gold film is soft, if the opposing contact portion is a hard nickel film, it is conceivable that the wear occurs early when the contacts are slid, and the contact resistance increases, and the contact characteristics are easily deteriorated. problem.

Further, when silver plating is applied to the fixed contact side as in Patent Document 1, the contact resistance characteristics after repeated sliding are correspondingly good, but it is not advantageous in terms of cost, and it is desired to obtain equivalent contact resistance characteristics. And a fixed joint that is advantageous in terms of cost.

Therefore, an object of the present invention is to provide an electric contact structure and a push button switch in which a movable contact member and a fixed contact member are combined, and the surface contact quality is not deteriorated even if it is used for a long period of time in an environment of a reverse switch. . Further, an object of the present invention is to provide an electric contact structure and a push button switch in which a movable contact member and a fixed contact member are combined with a small increase in contact resistance during long-term use.

The above problems of the present invention can be solved by the following solutions.

(1) An electric contact structure having a movable contact portion and a fixed contact portion, wherein the movable contact portion is constituted by a movable contact member having at least a part of a surface of the conductive substrate a base layer of a movable contact portion formed of any one of nickel, cobalt, a nickel alloy, or a cobalt alloy, and a surface layer of a movable contact portion made of silver or a silver alloy, the fixed contact portion being fixed by the following The point member is configured to have a fixed contact portion base layer made of copper or a copper alloy on the substrate, and a nickel, tin, zinc, nickel alloy, tin alloy, or zinc alloy is formed on the base layer of the fixed contact portion. The fixed contact portion formed by either of them is the outermost layer.

(2) The electric contact structure according to (1), wherein the conductive substrate used for the material for the movable contact portion is an iron-based substrate.

(3) The electric contact structure according to (1) or (2), wherein the surface of the movable contact portion has a thickness of 0.01 to 0.3 μm.

(4) The electric contact structure according to any one of (1) to (3), wherein the movable contact portion base layer and the movable contact portion surface layer have a movable connection made of copper or a copper alloy. The middle layer of the point.

(5) The electric contact structure according to (4), wherein the intermediate layer of the movable contact portion has a thickness of 0.01 to 0.09 μm.

(6) The electric contact structure according to any one of (1) to (5), wherein the surface of the movable contact portion has an organic film layer having a thickness of 1 to 3 μF ^-1 /cm ² .

(7) The electric contact structure according to any one of (1) to (6), wherein the base material of the fixed contact portion is a glass epoxy material.

(8) The electric contact structure according to any one of (1) to (7), wherein the fixed contact portion The thickness of the outermost layer is 0.5 to 10 μm.

(9) A push button switch having the electric contact structure according to any one of (1) to (8).

The numerical range expressed by "~" in the present invention means a range including the numerical values described before and after "~" as the lower limit value and the upper limit value.

The electric contact structure of the present invention is used for a long period of time in various use environments such as frequent repeated switching operations, and the contact resistance is low as a movable contact, and the adhesion of the surface plating layer is excellent also for repeated shear stress. And the contact resistance caused by the micro-sliding is suppressed from rising. With the electrical contact structure of the present invention, the life of the electrical contacts can be improved.

The above and other features and advantages of the present invention will become more apparent from the following description.

P‧‧‧ button switch

1‧‧‧ movable contact

2‧‧‧Fixed joints

5‧‧‧ Conductive substrate

6‧‧‧ Movable contact base layer

7‧‧‧ movable contact surface

8‧‧‧ movable contact components

9‧‧‧Substrate

10‧‧‧Fixed joint base layer

11‧‧‧The top layer of the fixed contact

12‧‧‧Fixed joint components

13‧‧‧Intermediate layer of movable contact

Fig. 1 is a plan view showing a push button switch as an example of an electric contact structure according to an embodiment of the present invention.

Fig. 2 is a cross-sectional view taken along line A-A of Fig. 1, (a) before the button switch operation, and (b) for the button switch operation.

Fig. 3 (a) is a cross-sectional structure of a movable contact portion of a push button switch according to an embodiment of the present invention, and Fig. 3 (b) is a view showing a fixed contact portion of a push button switch according to an embodiment of the present invention. Profile builder.

The preferred embodiment of the electrical contact structure of the present invention will be described.

(electrical contact construction)

The electric contact structure of the present embodiment is constituted by a movable contact member constituting a movable contact portion and a fixed contact member constituting a fixed contact portion.

3(a) is an example, and FIG. 3(b) shows an example of a cross-sectional structure of the movable contact portion 1 and the fixed contact portion 2 as an example.

As shown in FIG. 3(a), the movable contact portion 1 is composed of a movable contact member 8 having nickel, cobalt, a nickel alloy, or a cobalt alloy on at least a part of the surface of the conductive substrate 5. The movable contact portion underlayer 6 formed of either of them is formed with a movable contact portion surface layer 7 made of silver or a silver alloy.

Further, as shown in Fig. 3 (b), the fixed contact portion 2 is constituted by a fixed contact member 12 having a fixed connection made of copper or a copper alloy on a substrate 9 made of, for example, a resin. The dot base layer 10 is formed with a fixed contact portion outermost layer 11 made of any one of nickel, tin, zinc, a nickel alloy, a tin alloy, or a zinc alloy on the fixed contact portion base layer 10.

(movable contact part)

In the present embodiment, the conductive substrate 5 is preferably an iron-based substrate, and particularly preferably a stainless steel. When the stainless steel is used for the movable contact, it is preferably a rolled or tempered material such as SUS301, SUS304, or SUS316 which is excellent in stress relaxation characteristics and is less likely to cause fatigue damage. The conductive substrate 5 may be a copper substrate or the like in addition to the iron substrate.

In order to improve the adhesion, the movable contact portion underlayer 6 formed on the conductive substrate 5 may be selected from any of nickel, cobalt, a nickel alloy, and a cobalt alloy. In the base layer 6, the conductive substrate 5 is preferably used as a cathode, and electroplating is carried out using, for example, an electrolytic solution containing nickel chloride and free hydrochloric acid, whereby the thickness is plated to 0.05 to 2.0 μm. If the thickness of the base layer 6 of nickel or nickel alloy is too thin, then The effect is small, and if it is too thick, the motive force of the movable contact of the conductive substrate 5 is lowered. The nickel or cobalt which forms the base layer 6 of the movable contact portion is not limited, and is preferably nickel. In addition to pure nickel, a nickel alloy containing 1 to 10% by mass of cobalt (Co) may be contained. Further, a nickel-phosphorus (Ni-P) alloy, a nickel-tin (Ni-Sn) alloy, a nickel-cobalt (Ni-Co) alloy, a nickel-cobalt-phosphorus (Ni-Co-P) alloy, or a nickel can also be used. - Copper (Ni-Cu) alloy, nickel-chromium (Ni-Cr) alloy, nickel-zinc (Ni-Zn) alloy, nickel-iron (Ni-Fe) alloy, and the like.

The reason why the adhesion force of the layer made of silver or a silver alloy (the surface layer of the movable contact portion) is lowered is the oxidation of the underlying layer and the large repeated shear stress. On the other hand, in the present embodiment, as the means for preventing the underlying layer 6 from being oxidized, the intermediate layer 13 (movable contact portion intermediate layer) made of copper or a copper alloy may be disposed. By disposing the intermediate layer 13 composed of copper or a copper alloy, diffusion of silver and copper is generated to form an alloy layer composed of silver and copper. The silver-copper alloy layer serves to suppress oxygen permeation and prevent the adhesion from being lowered. Further, the shear stress is improved by combining a layer in which the layers in contact with each other (silver and copper, copper and nickel) are solid-solved. In the conventional silver layer-nickel layer, the solid solution concentration of nickel in silver is extremely small, and the breaking strength to shear stress is weak. According to the study by the inventors, the intermediate layer 13 is preferably formed from the viewpoint of forming a copper layer between silver and nickel to form an alloy at the interface between silver and copper to improve the shear strength.

The thickness of the intermediate layer 13 of the movable contact portion is preferably 0.01 to 0.09 μm. If the thickness of the copper or copper alloy layer is too thin, the effect of providing the layer is small, and if it is too thick, the power of the movable contact of the substrate is lowered, which is not preferable. The copper or copper alloy is not particularly limited, and copper, copper-gold (Cu-Au) alloy, copper-silver (Cu-Ag) alloy, copper-tin (Cu-Sn) alloy, copper-nickel (Cu) can be used. -Ni) alloy, or copper-indium (Cu-In) alloy or the like. Further, it may be one or two or more elements selected from the group consisting of tin (Sn), zinc (Zn), and nickel (Ni) in an amount of 1 to 10% by mass. Copper alloy.

A movable contact portion surface layer 7 made of silver or a silver alloy is provided on the surface layer of the movable contact portion 1. The thickness of the layer is preferably from 0.01 to 0.3 μm. As the silver alloy, an alloy obtained by adding 0.1 to 2.0% by mass of bismuth (Sb) to silver can be used in order to improve the wear resistance. The surface of the movable contact portion is mainly made of nickel with respect to the gold surface of the fixed contact portion 2 which has been used until now. However, since gold is expensive, it has been studied that the fixed contact portion 2 has silver or nickel as the outermost surface, but the cost of silver or the contact resistance of the surface of nickel has become a problem. Based on this background, the layer composed of silver or a silver alloy is thinned.

Therefore, it is preferable to provide an organic film having a thickness of 1 to 3 μF ^-1 /cm ² on the surface layer 7 of the movable contact portion. It is mainly set for the purpose of anti-rust of silver. Furthermore, the definition of "μF ^-1 /cm ² " is described at the end of the specification. The organic compound which can be used for the organic film in the present embodiment is a compound which is physically or chemically bonded to silver or a silver alloy. In the present embodiment, the physical bonding means a state in which a bonding or adsorption state is formed without a chemical bond species by using a weak bonding state such as van der Waals force. Further, the term "chemical bonding compound" means a compound having a bonding bond in a state in which a chemical bond state such as a covalent bond or a coordinate bond or a vanad bond is formed on the surface of a silver or a silver alloy. Or polarity, etc.

Examples of the organic compound which can be used in the above-mentioned organic film in the present embodiment include an ester, a carboxylic acid, an aliphatic amine, a mercaptan, etc., and a compound which can form a rust-preventing film having excellent corrosion resistance, and more preferably an aliphatic amine. Or thiol. By forming the film type from a mixture of an aliphatic amine or a thiol or a mixture of the two, the thickness of the formed organic film can be easily adjusted, and a rust-preventing film excellent in adhesion can be obtained. In the aliphatic amine and the mercaptan of the present embodiment, in consideration of corrosion resistance and length of a linear chain, an aliphatic amine and a mercaptan having a carbon number of 30 or less are particularly preferable. Specifically, Examples thereof include dodecylamine, eicosylamine, decylamine, octadecylamine, dodecylmercaptan, octadecyl mercaptan, eicosyl mercaptan, mercapto mercaptan, and octadecyl sulfur. Alcohol, etc.

The method for forming an organic film is preferably carried out by forming a movable contact portion underlayer 6 on a conductive substrate 5, and a movable contact portion surface layer 7 made of silver or a silver alloy, and then immersing it in a film. In the solution of the above organic compound. In addition to this, after the movable contact portion surface layer 7 is formed, the film formation treatment may be performed by a solution mist containing the organic compound or by wiping with a cloth soaked with the solution or the like. The concentration of the organic compound which is physically or chemically bonded to silver or a silver alloy in the above solution is not particularly limited, but is preferably 0.01 to 10% by mass. As the solvent, toluene, acetone, trichloroethane, a lactone solvent, an indoleamine solvent, a cyclic quinone-based organic solvent, or a commercially available synthetic solvent (for example, a hydrocarbon solvent NS Clean 100W; Name, manufactured by Japan Energy Co., Ltd.). Since these solvents volatilize and do not remain on the surface, they do not affect the anti-rust film. Further, the organic film treatment can be carried out without hindering the resin adhesion, and coating and drying can be easily achieved. Further, as a method of controlling the thickness of the organic compound film to be the thickness specified in the embodiment, it is possible to easily remove physical bonding or chemical bond with silver or a silver alloy by washing with the solvent for about 0.1 to 10 seconds. The residual portion of the organic compound is knotted to control the film thickness. Since the organic film component combined with silver or silver alloy is not removed in the cleaning step at this time, the rust-preventing treatment effect is not lost.

The treatment temperature and treatment time for forming the anti-rust film are not particularly limited, and the target anti-rust film can be formed by immersing at room temperature (25 ° C) for 0.1 second or longer (preferably 0.5 to 10 seconds). In the formation of the anti-rust film, the organic film may be formed twice or more, or the organic film formed of a mixed solution of two or more kinds of compounds may be formed twice or more. Alternatively, the forming process may be alternately performed. However, if the number of steps or the cost is considered, the forming process is preferably performed within three times. The rustproof film is preferably removed before the joint structure operation of the push button switch.

In the present embodiment, each of the movable contact portion underlayer 6, the movable contact portion intermediate layer 13, and the movable contact portion surface layer 7 can be formed by any method such as electroplating, electroless plating, or physical/chemical vapor deposition. These electroplating methods are most advantageous in terms of productivity and cost. Each of the above layers may be formed on the entire surface of the conductive substrate 5, but it is economical only to form a contact or a contact near the fixed contact portion.

Further, in order to increase the adhesion strength, diffusion treatment, in particular, diffusion of silver, is carried out by heat treatment in a non-oxidizing atmosphere to improve the shear strength. The reason for this is that the alloy layer of silver and copper is thick, but if the heat treatment is excessively continued, the silver of the surface layer is entirely alloyed, and the contact stability is deteriorated. Further, when the silver-copper alloy layer is thick, the electrical conductivity is lowered. The thickness of the silver-copper alloy layer is preferably 0.1 μm or less, and the heating condition is preferably 200 to 400 ° C × 1 minute to 5 hours. As the non-oxidizing atmosphere gas, hydrogen, helium, argon or nitrogen can be used, and argon is preferable.

(fixed contact part)

As shown in Fig. 3(b), the fixed contact portion 2 of the present embodiment is constituted by a fixed contact member 12 having a fixed contact portion base made of copper or a copper alloy on the base material 9. The layer 10 has a fixed contact portion outermost layer 11 made of any one of nickel, tin, zinc, a nickel alloy, a tin alloy, or a zinc alloy on the fixed contact portion base layer 10. As the substrate 9, for example, a printed base material such as FR-4 (Flame Retardant Type 4) is preferably used. Further, the base material 9 and the fixed contact portion base layer 10 of the fixed contact portion may be printed substrates having a copper pattern on the surface. That is, the resin portion of the printed substrate is the substrate 9, and the copper pattern of the printed substrate is the fixed contact portion. The bottom layer 10. In this case, the fixed contact member 12 can be formed by providing the outermost layer 11 of the fixed contact portion on the copper pattern of the printed substrate.

The fixed contact portion base layer 10 made of copper or a copper alloy is different from the movable contact portion base layer 6 or the movable contact portion intermediate layer 13 in a layer having a thickness of 50 μm or less. The copper or copper alloy is not particularly limited, and copper, copper-gold (Cu-Au) alloy, copper-silver (Cu-Ag) alloy, copper-tin (Cu-Sn) alloy, copper-nickel (Cu) can be used. -Ni) alloy, or copper-indium (Cu-In) alloy or the like. Further, it may be a copper alloy containing 1 to 10% by mass of one or more elements selected from the group consisting of tin (Sn), zinc (Zn), and nickel (Ni). The base layer may be provided by plating, or may be provided by, for example, crimping a copper foil to the resin substrate.

The outermost layer 11 of the fixed contact portion is made of any one of nickel, tin, zinc, a nickel alloy, a tin alloy, or a zinc alloy. The thickness thereof is preferably from 0.5 to 10 μm.

(electrical contact construction)

Specifically, the electric contact structure of the present embodiment can be applied as a so-called push button switch, and the type thereof is not particularly limited as long as it has the above-described movable contact portion 1 and fixed contact portion 2. By the interaction between the movable contact portion 1 and the fixed contact portion 2 of the present embodiment, the electrical contact structure can suppress the contact resistance and the contact resistance after sliding (the deviation of the contact resistance) In order to improve the adhesion of the surface metal.

(power switch button)

Fig. 1 is a plan view showing a push button switch P which is an example of the electric contact structure of the embodiment. 2 is a cross-sectional view taken along line A-A of FIG. 1 of the push button switch P. In Fig. 2, (a) is before the switching operation (before pressing), and (b) is when the switching operation is performed (after pressing). As shown in FIG. 1, the push button switch P has an electric contact structure composed of a hemispherical movable contact portion 1 and a fixed contact portion 2. These are fixed to the resin case 4 via the resin filler 3 .

The push button switch P of the present embodiment can suppress the occurrence of pinholes in the electric contact portion, and includes the contact resistance characteristics after the reverse sliding.

Hereinafter, the present invention will be described in further detail based on examples, but the present invention is not limited to the examples.

(movable contact part 1)

A conductive substrate having a thickness of 0.05 mm and a width of 180 mm is subjected to degreasing and pickling treatment in a usual manner as a pretreatment, and a base layer having a specific thickness <average thickness> is formed in a plating bath having the following composition. The intermediate layer 13 and the surface layer further form an organic film layer. The thicknesses of the base layer 6, the intermediate layer 13, and the surface layer 7 were measured by a fluorescent X-ray apparatus (device name: SFT9200, manufactured by SII Nano Technology Co., Ltd.). Furthermore, the average thickness is obtained by measuring the average of three points of the material. This is also the case in the case of the layers of the fixed contact member described below.

. Pretreatment conditions

[electrolytic degreasing]

Degreasing liquid: NaOH 60g / L (water)

Degreasing conditions: current density 2.5A/dm ² , temperature 60 ° C, degreasing time 60 seconds

[pickling]

Pickling solution: H ₂ SO ₄ 10% by mass solution

Pickling conditions: immersion at room temperature, immersion time 30 seconds

. Base layer plating treatment conditions

[Nickel plating treatment]

Plating solution: HCl 120g/L (water), NiCl ₂ 30g/L (water)

Plating conditions: current density 1.5A/dm ² , temperature 30°C

[Ni-plated cobalt-cobalt treatment]

Plating solution: HCl 120g/L (water), NiCl ₂ 30g/L (water), CoCl ₂ 30g/L (water)

Plating conditions: current density 1.5A/dm ² , temperature 30°C

. Intermediate layer plating treatment conditions

[copper plating]

Plating solution: CuSO ₄ . 5H ₂ O 250g/L (water), H ₂ SO ₄ 50g/L (water), NaCl 0.1g/L (water)

Plating conditions: current density 1~10A/dm ² , temperature 40°C

. Surface plating treatment conditions

[strike silver plating]

Plating solution: AgCN 5g/L (aqueous solution), KCN 60g/L (aqueous solution), K ₂ CO ₃ 30g/L (aqueous solution)

Plating conditions: current density 2A/dm ² , temperature 30 ° C

[Silver plating]

Plating solution: AgCN 50g/L (aqueous solution), KCN 100g/L (aqueous solution), K ₂ CO ₃ 30g/L (aqueous solution)

Plating conditions: current density 3A/dm ² , temperature 30 ° C

. Formation of organic film layer

Each sample subjected to the necessary plating treatment was immersed in a solution of a thiol-based organic compound to form an organic film.

Impregnation solution: 0.5% by mass organic compound solution (solvent toluene)

Impregnation conditions: after immersing for 5 seconds at room temperature, washing with solvent toluene for 5 seconds

Drying: 40 ° C 30 seconds

(fixed contact part 2)

The base layer and the outermost layer described below were formed on the resin substrate (FR-4).

Basal layer formation conditions

A copper foil (rolled copper foil or electrolytic copper foil) having a thickness of 35 μm was attached to the resin substrate by hot pressing.

Hot pressing conditions: 150 ° C, 1 hour, pressure 1 MPa

The outermost layer is formed by plating on the base layer.

. Surface coating treatment conditions

[Nickel plating treatment]

Plating solution: HCl 120g/L (water), NiCl ₂ 30g/L (water)

Plating conditions: current density 1.5A/dm ² , temperature 30°C

[tin plating treatment]

Plating solution: tin (II) sulfate 60g / L (water), H ₂ SO ₄ 98g / L (water)

Plating conditions: current density 1A/dm ² , temperature 30 ° C

[galvanized treatment]

Plating solution: zinc sulfate 60g / L (water), H ₂ SO ₄ 98g / L (water)

Plating conditions: current density 1A/dm ² , temperature 30 ° C

[Gold plating treatment]

Plating solution: RONOVEL C manufactured by Meltex, metal concentration 4g/L (water)

Plating conditions: current density 2Adm ² , temperature 60 ° C

(electrical contact construction)

The movable contact portion 1 obtained is processed into a diameter of 4 mm. The hemispherical movable contact member processes the obtained fixed contact portion 2 into a specific shape to form an electric contact structure as a push button switch as shown in Figs. The configuration of the embodiments of the movable contact portion 1 and the fixed contact portion 2 is summarized in Table 1.

The following test was conducted on the electrical contact structure shown in Table 1. Consolidate the results into a table 2.

(no sliding contact resistance test)

The contact resistance of the electrical contact structure was measured using a 4-terminal method after initial, atmospheric heating (85 ° C - 240 hr.), high temperature and high humidity (60 ° C, 95% RH, 240 hr.).

Measurement conditions: Prepare the movable contact side material for the test and the fixed contact side material for the test. A hemispherical protrusion having a curvature radius of 1.05 mm is provided on the movable contact side material (the outer surface of the convex portion is the outermost layer). The outermost layer of the material on the fixed contact side was brought into contact with the hemispherical projection by a load of 1 N, and the resistance value at the time of 10 times of energization of 5 mA was measured by a four-terminal method, and the average value was calculated.

Further, the results were evaluated by the following criteria.

A Contact resistance (all conditions) is less than 40mΩ.

B The contact resistance value of one or more conditions is 40 mΩ or more and less than 100 mΩ.

C Other than the above (the value of the contact resistance of any one or more conditions is 100 mΩ or more.)

(adhesion test)

After the test piece of the movable contact portion 1 was cut into 10 mm × 30 mm, a 2 mm square cross-cut was performed by a cutter. Then, the #631S tape manufactured by Teraoka Seisakusho Co., Ltd. was used for peeling, and the plating adhesion test was performed. The adhesion is based on any of the criteria of peeling (evaluated as "peeling" in Table 2, "NG" when peeling only a part), and no peeling ("OK" in Table 2). Conduct an evaluation.

(sliding contact resistance test)

The sliding contact resistance test (micro sliding wear test) was carried out as follows.

The test plating material for the movable contact portion 1 and the fixed contact portion 2 is prepared. A hemispherical protrusion having a radius of curvature of 1.05 mm is provided on the plating material of the movable contact portion 1 (the outer surface of the convex portion is the outermost layer) surface). After degreasing and cleaning, the outermost layer of the plating material of the fixed contact portion is brought into contact with the hemispherical protrusion at a contact pressure of 1 N. In this state, the sliding distance is 10 μm in an environment of a temperature of 20 ° C and a humidity of 50%. The slide was slid back and forth, and an open circuit voltage of 20 mV was applied between the two plating materials, and a constant current of 5 mA was flowed. The voltage drop during sliding was measured by the 4-terminal method, and the change in resistance was obtained every one second. The contact resistance value (initial value) before the micro sliding test and the maximum contact resistance value (maximum value) in the micro sliding test are shown in Table 2. Furthermore, the round-trip motion frequency is performed at about 6.8 Hz. Here, one round trip is counted as one.

The result is also determined by the following criteria.

A Contact resistance (all conditions) is less than 40mΩ.

B The contact resistance value of one or more conditions is 40 mΩ or more and less than 60 mΩ.

The value of the contact resistance of one or more of C is 60 mΩ or more and less than 100 mΩ.

The value of the contact resistance of one or more of D is 100 mΩ or more.

(comprehensive characteristics)

The evaluation of the comprehensive characteristics was carried out in accordance with the following criteria.

A: The judgment of the non-sliding contact resistance test was A, the judgment of the contact resistance test after sliding was A~C, and the judgment of the adhesion test was OK.

B: The judgment of the non-sliding contact resistance test was B, the judgment of the contact resistance test after sliding was A~C, and the judgment of the adhesion test was OK.

C: The judgment of the non-sliding contact resistance test is C, the judgment of the contact resistance test after sliding is A~C, and the judgment of the adhesion test is OK.

D: The judgment of the contact resistance test after sliding is D or the judgment of the adhesion test is NG.

According to the results of the comprehensive tables 1, 2, the comprehensive judgment of the conventional example 1 is D, which is uncomfortable. Practical. On the other hand, it can be seen that the comprehensive determination of the products of the present embodiment shown in Inventive Examples 1 to 41 reaches A to C, and particularly has excellent contact resistance characteristics after the sliding contact resistance test, and has an excellent movable contact structure. Moreover, it is understood that the contact resistance is extremely low even after heat treatment in the air, and it is very excellent in film adhesion.

Regarding the results of the non-sliding contact resistance test, the results of the articles of this example were dispersed in A to C. In the invention example 14, the thickness of the surface layer 7 of the movable contact portion is considered to be 0.01 to 0.3 μm (more preferably 0.03 to 0.2 μm), and the thickness of the intermediate layer 13 of the movable contact portion is considered in consideration of the relationship with other results. When 0.01 to 0.09 μm (more preferably 0.15 to 0.05 μm) and the thickness of the outermost layer 11 of the fixed contact portion is 0.5 to 10 μm (more preferably 3 to 8 μm), optimum characteristics are obtained, and the respective characteristics are satisfied. In the case of any of the numerical ranges or more, it is suitable as the present embodiment.

In the above-described embodiments and examples, the resin substrate is used as the substrate on the side of the fixed contact portion 2, but is not particularly limited. For example, a rigid substrate such as a glass epoxy board or a PET film or a polyethylene film may be used. A substrate made of a flexible film material such as a flexible film material, a copper or copper alloy such as brass or oxygen-free copper, an iron or iron alloy such as SUS301, or an aluminum-copper alloy such as A11071.

(Definition and measurement method of the unit "μF ^-1 /cm ² " in this manual)

The "μF ^-1 /cm ² " is a unit for specifying the thickness of the organic film on the metal using the electric double layer capacitor, and is the inverse of the electric double layer capacitor 1/C.

The measurement method is as follows: the principle is based on the 4-terminal method, more specifically, the sample to be measured is immersed in the aqueous electrolyte solution, a step current is flowed between the opposite electrode, and the reference electrode and the measured test are calculated by the electronic circuit. The transient characteristics of the voltage between the samples are used to measure the electric double layer capacitance C. Here, C has the following relationship with the thickness d of the sample.

1/C=A. d+B (A and B are proportional constants)

Therefore, by obtaining the value of 1/C, the relative value of the thickness of the dielectric film on the surface of the sample can be obtained.

The present application claims the priority of Japanese Patent Application No. 2013-196281, the entire disclosure of which is hereby incorporated by reference.

1‧‧‧ movable contact

2‧‧‧Fixed joints

5‧‧‧ Conductive substrate

6‧‧‧ Movable contact base layer

7‧‧‧ movable contact surface

8‧‧‧ movable contact components

9‧‧‧Substrate

10‧‧‧Fixed joint base layer

11‧‧‧The top layer of the fixed contact

12‧‧‧Fixed joint components

13‧‧‧Intermediate layer of movable contact

Claims (9)

An electric contact structure having a movable contact portion and a fixed contact portion, wherein the movable contact portion is composed of a movable contact member having nickel or cobalt on at least a part of a surface of the conductive substrate a base layer of a movable contact portion formed of either a nickel alloy or a cobalt alloy, and a surface of a movable contact portion made of silver or a silver alloy, which is composed of the following fixed contact members a base layer having a fixed contact portion made of copper or a copper alloy on a substrate, and a nickel, tin, zinc, nickel alloy, tin alloy, or zinc alloy formed on the base layer of the fixed contact portion The fixed contact portion formed by the person is the outermost layer. The electrical contact structure of the first aspect of the invention, wherein the conductive substrate of the movable contact portion is an iron-based substrate. The electrical contact structure of claim 1 or 2, wherein the surface of the movable contact portion has a thickness of 0.01 to 0.3 μm. The electric contact structure according to any one of claims 1 to 3, wherein the movable contact portion between the base layer of the movable contact portion and the surface layer of the movable contact portion has a movable contact portion made of copper or a copper alloy Floor. The electrical contact structure of claim 4, wherein the intermediate layer of the movable contact portion has a thickness of 0.01 to 0.09 μm. The electric contact structure according to any one of claims 1 to 5, wherein the movable contact portion has an organic film layer having a thickness of 1 to 3 μF ^-1 /cm ² . The electrical contact structure of any one of claims 1 to 6, wherein the substrate of the fixed contact member is a glass epoxy material. The electrical contact structure according to any one of claims 1 to 7, wherein the thickness of the outermost layer of the fixed contact portion is 0.5 to 10 μm. A push button switch having the electrical contact configuration of any one of claims 1 to 8.