JP2014065949A - Composite plating material, manufacturing method thereof, electrical and electronic parts, fitting terminal and connector, sliding or rotating contact and switch - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a composite plating material having capsules containing liquid materials uniformly dispersed in a plating film.SOLUTION: There is provided a method of manufacturing a composite plating material, electrical and electronic parts and a plating material, containing a base plated layer 2 having a thickness of 0.05 to 2.0 μm and a surface plated layer 3 containing capsules 4 containing liquid materials and having a thickness of 0.5 to 10 μm on both sides of a conductive base material 1. The average grain diameter of the capsules 4 is 0.01 to 1 μm, and one of a specific gravity of the capsule 4 containing liquid materials or organic solvent-soluble materials is 1-x and another is 1+y based on a plating liquid of the surface plated layer at 25°C, where x and y are each 0.1 to 0.3, and one surface plated layer containing capsules with the specific gravity of 1-x and another surface plated layer containing capsules with the specific gravity of 1+y.

Description

  The present invention relates to a composite plating material in which capsules having a uniform concentration are contained in surface plating layers on both surfaces of a base material, and a method for producing the same. More specifically, the present invention relates to a composite plating material suitable as a material for electrical / electronic parts, fitting type terminals / connectors, sliding type and rotary type contacts / switches.

  A material in which a plating layer made of noble metals such as silver (Ag) or tin (Sn) is provided on a conductive substrate made of copper (Cu), Cu alloy, stainless steel (SUS), iron alloy or the like. Is widely used for various contacts, switches, terminals and the like as a high-performance conductor having both excellent conductivity and strength of the base material and good electrical contact characteristics of the plated metal.

  The plating thickness of the plating material is often determined by the use environment, energized state, cost, and the like. In order to improve the environmental resistance of the structural material or the like, a thick plating is performed. However, the plating material for contact used in a place with sliding has a problem that scraping generated during sliding becomes sliding resistance. Therefore, the plating thickness is often set to be relatively thin for the purpose of reducing the amount of scraping and keeping the sliding resistance low.

  In addition, it has been reported that fine plating composed of carbon or silicon is compositely plated in a plating film for the purpose of reducing sliding resistance (see, for example, Patent Documents 1 and 2). In addition, resin particles such as PTFE (polytetrafluoroethylene) may coexist in a relatively thick electroless nickel plating in car engines and mechanical parts.

  On the other hand, it has been proposed that microcapsules coexist in a plating film (see, for example, Patent Documents 3 and 4). The problem here is the specific gravity of the capsule. When the specific gravity of the capsule is small relative to the plating solution, the capsule floats in the plating solution, and when the specific gravity of the capsule is large, the capsule sinks. Even when plating is performed using the same plating solution, when the specific gravity of the capsules is different, there is a problem that the amount of capsules that are eutectoid on the plating film varies depending on the location or is not eutectoid at all.

JP-A-61-101919 JP 2000-508379 JP 2008-248294 A JP 2008-248295 A

  The present invention maintains the electrical contact characteristics, corrosion resistance, and solderability as a plating material, improves the strength and wear resistance, improves the life and productivity, has excellent bending workability, and provides a basis for plating. It is an object of the present invention to provide a composite plating material in which capsules of a uniform concentration are contained in the surface plating layer, and further a composite plating material excellent in oxidation resistance, sulfidation resistance and corrosion resistance regardless of the position of the material. In addition, the present invention provides a method for producing a composite plating material having such characteristics, electric / electronic parts using the composite plating material, fitting type terminals / connectors, sliding type or rotary type contacts, and switches. The purpose is to provide.

In the present invention, the above object is achieved by the following plating materials, electrical / electronic components, fitting type terminals / connectors, sliding type or rotating type contacts or switches.
That is, the said subject was achieved by the following means.
(1) A composite plating material having a single underlying plating layer on both surfaces of a conductive substrate, and having a surface plating layer on the underlying plating layer,
The thickness of the base plating layer is 0.05 to 2.0 μm, the thickness t of the surface plating layer is 0.5 to 10 μm, and the surface plating layer includes a liquid substance or an organic solvent soluble substance. Capsules having an average particle diameter r of 0.01 to 1 μm, and the specific gravity of the capsule containing the liquid substance is x and y with respect to the plating solution of the surface plating layer at 25 ° C. When 0.1 to 0.3, one is 1-x, the other is 1 + y, one surface plating layer is a capsule having a specific gravity of 1-x, and the other surface plating layer is a capsule having a specific gravity of 1 + y A composite plating material characterized by comprising:
(2) The composite plating material according to (1), wherein the surface plating layer is made of tin, silver, or an alloy containing these elements.
(3) The capsule is contained in an amount of 5.0 to 30% by volume with respect to the total volume of the surface plating layer on the surface, the inside, or both of the surface plating layer (1) or (2) The composite plating material described in 1.
(4) The composite plating material according to any one of (1) to (3), wherein the base plating layer is made of copper, nickel, cobalt, iron, silver, or an alloy containing these elements. .
(5) Any one of (1) to (4), wherein the liquid substance or the organic solvent soluble substance is a substance selected from a lubricant, a sulfide-resistant agent, a rust inhibitor, and a discoloration inhibitor. The composite plating material according to Item 1.
(6) An electrical / electronic component formed by using the composite plating material according to any one of (1) to (5).
(7) A fitting-type terminal / connector, sliding type or rotary type contact formed by using the composite plating material according to any one of (1) to (5) above Member or switch.
(8) A method for producing a composite plating material, in which after a base plating layer is formed on both surfaces of a conductive substrate, a surface plating layer is formed on the base plating layer,
The thickness of the base plating layer is 0.05 to 2.0 μm, the thickness t of the surface plating layer is 0.5 to 10 μm, and the surface plating layer includes a liquid substance or an organic solvent soluble substance. Capsules having an average particle diameter r of 0.01 to 1 μm, and the specific gravity of the capsule containing the liquid substance is x and y with respect to the plating solution of the surface plating layer at 25 ° C. When 0.1 to 0.3, one is 1-x, the other is 1 + y, one surface plating layer is a capsule having a specific gravity of 1-x, and the other surface plating layer is a capsule having a specific gravity of 1 + y A method for producing a composite plating material, comprising:
(9) The method for producing a composite plating material according to (8), wherein the surface plating layer is made of tin, silver, or an alloy containing these elements.
(10) The capsule is contained in an amount of 5.0 to 30% by volume with respect to the total volume of the surface plating layer on the surface plating layer or inside or both of the surface plating layer (8) or (9) The manufacturing method of the composite plating material as described in any one of.
(11) The composite plating material according to any one of (8) to (10), wherein the base plating layer is made of copper, nickel, cobalt, iron, silver, or an alloy containing these elements. Manufacturing method.
(12) Any one of (8) to (11), wherein the liquid substance or the organic solvent soluble substance is a substance selected from a lubricant, a sulfide-resistant agent, a rust inhibitor, and a discoloration inhibitor. 2. A method for producing a composite plating material according to item 1.

According to the present invention, the electrical contact characteristics, corrosion resistance, and solderability as a plating material are maintained, the strength and wear resistance are improved, the life and productivity are improved, the bending workability is excellent, and the oxidation resistance is also improved. In addition, a composite plating material excellent in sulfidation resistance and corrosion resistance and a method for producing the same can be provided.
In addition, the specific gravity of the liquid substance contained in the capsule and the capsule itself can be adjusted, the specific gravity of the entire capsule can be adjusted, and the dispersion state of the capsule can be controlled. As a result, it is possible to stably manufacture a plating material in which capsules having a uniform concentration are co-deposited regardless of the position of the substrate during plating.

  In particular, the composite plating material obtained by the present invention has a lubricant, rust preventive, antisulfurizing agent, discoloration in the surface layer portion or inside of the surface plating layer (preferably made of tin, silver or an alloy containing these elements). By dispersing capsules containing liquid substances such as inhibitors, when the plating material is slid, the capsules are sequentially broken during wear, and the contained liquid substances ooze out. In addition, the effect of the liquid substance encapsulated in the capsule can be continuously obtained. Because of such characteristics, for example, it is a composite plating material suitable as a material for fitting type terminals / connectors of electric / electronic parts, sliding type and rotary type contacts / switches.

It is a schematic diagram of the cross section which shows preferable embodiment of the plating material of this invention. It is a schematic diagram in case the specific gravity of a capsule is large with respect to a plating bath. It is a schematic diagram in case the specific gravity of a capsule is small with respect to a plating bath. It is a schematic diagram in the case where a capsule having a higher specific gravity than a plating bath and a capsule having a lower specific gravity are mixed. It is a schematic diagram of a capsule.

  In the composite plating material of the present invention, a surface plating layer made of Sn, Ag, or an alloy containing these elements is formed on both surfaces of a conductive substrate, and a lubricant, a rust preventive, It has a capsule containing at least one kind of liquid substance or organic solvent soluble substance such as a sulfurizing agent and a discoloration preventing agent.

  A particularly preferred embodiment of the composite plating material of the present invention is that, as shown in the schematic cross-sectional view of FIG. 1, at least one base plating layer 2 is formed on both surfaces of the conductive substrate 1, and the surface plating layer 3 is further formed thereon. And a capsule 4 containing a liquid substance such as a lubricant, a rust preventive, a sulfidation preventive or a discoloration preventive substance or an organic solvent soluble substance on both sides of the substrate. It has a structure in which it is dispersed without concentration unevenness.

  The material of the conductive substrate 1 is not particularly limited. For example, in consideration of the use as a connector, depending on the required mechanical strength, heat resistance, and conductivity, for example, pure copper; phosphor bronze, brass Copper alloy such as iron white, beryllium copper, corson alloy; pure iron; iron alloy such as stainless steel; various Ni alloys; composite materials such as Cu coating materials and Ni coating materials may be appropriately selected. . Moreover, as a shape of an electroconductive base material, a strip material and a board | plate material are preferable.

  Of these materials of the conductive substrate 1, Cu or Cu alloy is preferable. In addition, even when the conductive substrate 1 is not a Cu-based material, surface plating is performed by applying a base plating containing copper, nickel, cobalt, iron, silver, or an alloy containing these elements, and then putting it into actual use. Improvements in layer adhesion and corrosion resistance can be expected.

  The base plating layer 2 formed on both surfaces of the conductive base material 1 improves the adhesion between the conductive base material 1 and the surface plating layer 3 and prevents the base material component from thermally diffusing to the surface layer side. It also functions as a layer. When a refractory metal having a melting point of 1000 ° C. or higher is used for the base plating layer 2, the base plating layer 2 is unlikely to cause thermal diffusion in a thermal history of 200 ° C. or lower that is generally received by contacts or switches. It effectively prevents components from thermally diffusing to the surface layer side. Of the refractory metals, Cu, Ni, cobalt (Co), iron (Fe), and silver (Ag) are preferable from the viewpoint of cost and ease of plating. Further, an alloy plating layer containing these elements and a compound layer obtained by alloying by heat treatment after plating are also effective. For example, Cu—Sn, Ni—Sn, Ni—P, Co—P, Ni—Co, Ni -Co-P, Ni-Cu, Ni-Fe, etc. can be mentioned.

  In addition, the base plating layer 2 may be a laminate of two or more layers having different components and characteristics as required. For example, a Ni layer can be provided as the first undercoat layer on the conductive substrate 1, Cu can be provided as the second undercoat layer thereon, and the surface plating layer 3 can be provided thereon. In such a composite plating material, the further improvement of the adhesiveness of a base layer and a surface plating layer is acquired. Especially when the surface plating layer 3 is made of Ag, the adhesion with the surface plating layer is remarkably improved by forming an Ag strike plating layer as the second undercoat plating layer between the base plating layer and the surface plating layer. Can do.

  The thickness of the base plating layer 2 is 0.05 to 2.0 μm in the present invention. When the thickness of the base plating layer 2 is less than 0.05 μm, the effect of preventing heat diffusion to the surface layer side of the conductive base material component is not sufficiently exhibited as described above. Moreover, when the thickness of the base plating layer 2 is larger than 2.0 μm, the effect of preventing thermal diffusion is saturated, and further, there is a high possibility of causing processing cracks during the forming process.

  The surface plating layer 3 is obtained by forming Sn, Ag or an alloy containing these elements by electrolytic plating or electroless plating using a plating solution in which the capsules 4 are dispersed, and has an electrical contact characteristic as a plating material. It is provided to ensure corrosion resistance and solderability. When the surface plating layer is an alloy, the wear resistance can be improved. The thickness of the surface plating layer is preferably 0.5 to 10 μm and more preferably 0.5 to 2 μm from the viewpoint of life and productivity. When the surface plating layer is less than 0.5 μm, the contact resistance during heat treatment is significantly increased, and the life of the composite plating material is shortened.

  In the present invention, the amount of capsules contained in the surface plating layer is preferably 5.0% by volume or more, and preferably in the range of 5.0 to 30% by volume. When the amount is less than 5.0% by volume, the effect of the liquid substance or organic solvent soluble substance contained in the capsule may not be sufficiently obtained during sliding. Moreover, when larger than 30 volume%, a contact resistance increases and the intensity | strength of a surface plating layer may fall. The amount of capsules contained in the surface plating layer can be adjusted by the capsule concentration in the plating solution, the specific gravity difference between the plating solution and the capsule, the current density, and the stirring speed. In order to cause the capsules to eutect in the surface plating layer, it is preferable that the capsules are in a dispersed state in the plating solution. In order to improve the dispersibility of the capsule in the plating solution, a surfactant may be used. There is no restriction | limiting in particular in the kind of surfactant, For example, anionic, cationic, nonionic, and amphoteric surfactant can be used. When the surfactant treatment is not performed and the dispersibility in the solution is poor, the capsules may aggregate and become coarse in the plating solution, and the capsules may not be sufficiently taken up when the plating layer is formed.

  When the surface plating layer is formed, the capsules precipitate or float as shown in the schematic diagram of FIG. 3 due to the specific gravity difference between the plating solution and the capsules in the plating bath 5. Thereby, since the density | concentration in the plating bath of the capsule 4 in a plating solution rises only in the electroconductive base-material vicinity, a capsule can be efficiently taken in in a surface plating layer. In the present invention, a capsule containing a liquid substance or an organic solvent-soluble substance is contained, and the specific gravity of the capsule containing the liquid substance or the organic solvent-soluble substance (specific gravity of the entire capsule including the inclusion substance) is: With respect to the specific gravity of the 25 ° C. plating solution (plating solution of the surface plating layer), that is, when the specific gravity of the plating solution is 1, a capsule having a specific gravity of 1-x is placed on one surface plating layer, and the other surface plating layer Includes capsules with a specific gravity of 1 + y. Here, x and y are each 0.1 to 0.3. As shown in the schematic diagram of FIG. 4, the capsule 4 can be efficiently taken into the surface plating layer on both sides of the conductive substrate.

When x and y are smaller than 0.1, the capsule concentration is not increased by the plating solution near both surfaces of the conductive substrate when the surface plating layer is formed, and the capsule cannot be efficiently taken into the surface plating layer. Also, by increasing the capsule concentration in the original plating solution, the capsule concentration in the plating solution near the surface of the conductive substrate can be increased even when x and y are smaller than 0.1. Further, since the amount of capsules mixed with the plating solution increases, the productivity is poor, and further, the performance of the plating solution may be deteriorated.
When x and y are larger than 0.3, the specific gravity difference is too large, so that the capsule concentration in the plating solution in the vicinity of both surfaces of the conductive substrate at the time of forming the surface plating layer is too high, and the capsule is good in the plating solution. The dispersed state cannot be maintained, and the amount of capsules taken into the surface plating layer is reduced.
In the present invention, it is preferable to use a capsule having a low specific gravity on the lower surface (gravity direction) of both surfaces of the conductive base material and a capsule having a high specific gravity on the upper surface.

  In order to increase the amount of capsules contained in the surface plating layer on the upper surface of the conductive substrate, it is effective to increase y, and the amount of capsules contained in the surface plating layer on the upper surface of the conductive substrate is decreased. In order to achieve this, it is effective to reduce y. Similarly, to increase the amount of capsules contained in the surface plating layer on the lower surface of the conductive substrate, it is effective to increase x, and the amount of capsules contained in the surface plating layer on the lower surface of the substrate is reduced. To reduce it, it is effective to reduce x. By appropriately controlling x and y, the concentration of the capsules 4 in the plating solution near the both surfaces of the conductive base material is not biased, and the capsule concentration in the formed surface plating layer is also reduced by the conductive base material. No bias occurs on both sides. In addition, the values of x and y do not always coincide with each other, and both the x and y values are within the range of 0.1 to 0.3, so that capsules with a uniform concentration are included in the surface plating layer. Plating material is obtained.

  Specifically, by adjusting the specific gravity of the plating solution at 25 ° C. to 0.7 to 0.9 and / or 1.1 to 1.3, the specific gravity of the whole capsule is adjusted, and the dispersion state of the capsule is changed. Can be controlled. As a result, it is possible to stably manufacture a plating material in which capsules having a uniform concentration are co-deposited regardless of the position of the substrate during plating.

  That is, when the specific gravity is less than 0.7 or greater than 1.3, the difference in specific gravity between the capsule and the plating solution is too large, so that the capsule concentration in the plating solution near the surface of the conductive substrate when the surface plating layer is formed increases. However, the capsule cannot maintain a good dispersion state in the plating solution, and the amount of the capsule taken into the surface plating layer may be reduced. When the specific gravity is less than 0.7, the capsule concentration in the plating solution may increase excessively on the lower surface of the conductive substrate, and when it is greater than 1.3, the upper surface of the conductive substrate.

  When the specific gravity is more than 0.9 and less than 1.1, the specific gravity of the capsule is almost the same as the specific gravity of the plating solution. Therefore, when the surface plating layer is formed, the capsule concentration is increased by the plating solution near the surface of the conductive substrate. It does not occur, and there is a possibility that the capsule cannot be efficiently taken into the surface plating layer.

  As will be described later, the specific gravity of the capsule can be adjusted by adjusting the specific gravity of the liquid substance or organic solvent soluble substance contained in the capsule. The specific gravity can be adjusted by mixing a non-polar solvent such as toluene or chloroform when the liquid substance or the organic solvent-soluble substance is a non-polar substance, and mixing a polar solvent such as water or alcohol when the substance is a polar substance.

  As shown in FIG. 5, the capsule has a structure in which a liquid substance or an organic solvent soluble substance-containing substance 7 is included inside the wall material 6. The method for producing the capsule 4 is not particularly limited, and for example, an interfacial polymerization method, a suspension polymerization method, a dispersion polymerization method, a liquid drying method, a coacervation method, a sol-gel method, or the like can be used.

The material of the capsule wall material 6 is not particularly limited. For example, an inorganic polymer such as an organic polymer such as polyamide, polyester, polyurethane, or polystyrene, or a metal oxide such as silica or titania. Can be used.
The specific gravity of the capsule itself is determined by the type of capsule wall and the wall thickness. The type can be changed depending on the chemicals and monomers used, and the wall thickness can be controlled by the degree of polymerization, and can be adjusted by the concentration of the chemicals and monomers used.
The wall thickness is preferably 0.7 to 0.8 moles of monomer per liter.

Capsule 4 is synthesized by an interfacial polymerization method, and if it is desired to lower the specific gravity of the liquid substance or organic solvent soluble substance to be included, a solvent having a small specific gravity is mixed with the liquid substance or organic solvent soluble substance, and the capsule is subjected to interfacial polymerization. . On the other hand, when it is desired to increase the specific gravity, the specific gravity of the liquid substance or the organic solvent soluble substance can be lowered by mixing the solvent having a large specific gravity and then performing interfacial polymerization of the capsule.
When the solvent added to adjust the specific gravity is different from the original liquid substance or organic solvent soluble substance, when the amount added exceeds 80% by volume with respect to the amount of the liquid substance or organic solvent soluble substance, Care must be taken because the performance of liquid substances or organic solvent-soluble substances may be impaired. When the liquid substance or organic solvent soluble substance is a nonpolar substance, it is preferable to add a nonpolar solvent such as toluene or chloroform, and when it is a polar substance, a polar solvent such as water or alcohol is preferably added. Is preferably 80% by volume or less. Furthermore, it is more preferable that the addition amount is 50% by volume or less.

  The liquid substance contained in the capsule 4 or the organic substance-soluble substance-containing substance 7 is preferably an organic compound, and examples thereof include lubricants, rust preventives, antisulfurizing agents (antisulfurizing agents), and discoloration preventing agents. Although these can use the substance generally used, it is desirable to use the chemical | medical agent with little influence on contact resistance considering that it is used for the application which aims at electrical connection.

  Examples of the lubricant can be selected from paraffinic and olefinic mineral oils and synthetic oils, higher alcohols, polyhydric alcohols or ethers thereof, higher fatty acids or esters thereof, and the like. Examples of sulfur-proofing agents, rust-preventing agents and anti-discoloring agents include nitrogen-containing heterocyclic compounds such as benzotriazoles and imidazoles, sulfur-containing compounds such as mercaptans, thiazoles and organic disulfide compounds, and organic phosphate compounds. And phosphorus-containing compounds such as

Here, the liquid substance is a substance that is liquid at 25 ° C., and the organic solvent-soluble substance is a substance that is soluble in an organic solvent, and has a mass of 0 dissolved in 100 g of the organic solvent at 25 ° C., for example. .1g or more substance. In the present invention, the substance contained in the capsule 4 is preferably in a liquid state. For this reason, any “organic solvent” in the “organic solvent soluble” may be used. It is an organic solvent added to adjust the specific gravity. For example, in addition to the alcohols such as methanol and ethanol, aromatic ring compounds such as toluene and chlorobenzene, halogen compounds such as chloroform, esters such as ethyl acetate, ethers such as THF and dioxane, and DMF. Examples thereof include cyclic hydrocarbons such as amide and hexane.
In the present invention, the substance contained in the capsule 4 is preferably a liquid substance.

  When forming the surface plating layer, the capsules dispersed in the plating solution may be used by mixing two or more kinds of encapsulated liquid substances or organic solvent soluble substances. In this case, when the surface plating layer slides, the effects of the respective liquid substances or organic solvent soluble substances can be obtained simultaneously.

  The particle size r of the capsule 4 is 0.01 to 1 μm, and preferably 0.01 to 0.5 μm. The particle size is an average particle size, and the particle size dispersed in the actual plating film may vary. When the particle size is smaller than 0.01 μm, the effect of improving the film properties by the capsule cannot be obtained during sliding. When the particle diameter is larger than 1 μm, problems such as an increase in contact resistance and a decrease in mechanical strength of the surface plating layer occur.

  As for the shape of a capsule, arbitrary shapes, such as spherical shape and an ellipsoid shape, are mentioned, for example. Further, the particle diameter of the capsule means a major axis in a shape other than a spherical shape, for example, an ellipsoidal shape.

  The particle size r of the capsule 4 is preferably t> 1 / 2r with respect to the thickness t of the surface plating layer. In the case of t ≦ 1 / 2r, the capsule 4 may fall off from the surface plating layer 3 after the surface plating layer is formed, and the effect of the liquid substance contained in the capsule 4 may not be obtained when sliding.

  The plating method is not particularly limited, and any method may be used as long as the capsule concentration can be increased in the vicinity of both surfaces of the substrate during plating. For example, capsules with different specific gravity are uniformly dispersed in the plating solution by stirring before plating, and the substrate is passed through the plating solution in which stirring is weakened at the time of plating. Can be raised. In addition, the plating tank is divided by a base material, a plating solution containing capsules with a high specific gravity with respect to the plating solution is placed on the upper side of the base material, and a plating solution containing capsules with a low specific gravity with respect to the plating solution is placed on the lower side of the base material. By arranging and plating, the capsule concentration can be increased in the vicinity of both surfaces of the substrate during plating.

  The composite plating material of the present invention can be used in place of the conventional metal materials used for electric / electronic parts, and in particular, electric / electronic parts fitting type terminals / connectors, sliding type or rotating type It can be suitably used as a material for contacts or switches.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to this.

  About each plating material produced as follows, the capsule density | concentration contained in the surface plating layer on both sides of a base material, a friction coefficient, contact resistance, durability, oxidation resistance, sulfidation resistance, and bending workability were evaluated. The evaluation method is as follows.

<Capsule concentration>
The cross section of the plating material was directly observed with an electron microscope, and the volume ratio of the capsule was measured from the observed image. The upper surface of the substrate during plating was the upper surface, and the lower surface was the lower surface. Further, the deviation of the capsule concentration on each surface with respect to the average value of the capsule concentration contained in the surface plating layer on the upper surface and the lower surface is shown as a percentage as a concentration deviation.

<Friction coefficient>
Using a Bowden type friction tester, the dynamic friction coefficient after sliding 100 times reciprocally when the surface of the conductive substrate was slid was evaluated. The measurement conditions were a load of 2.94 N (300 gf) for the Sn plating material, 0.98 N (100 gf) for the Ag plating material, a sliding distance of 10 mm, and a sliding speed of 100 mm / min. The mating material was a 3 mmR steel ball probe.

  The coefficient of friction was evaluated only for the plating material including the capsule containing the lubricant and the plating material not including the capsule. When the effect of the lubricant is sufficiently obtained during sliding, the friction coefficient is 0.20 or less.

<Contact resistance>
The evaluation was made by measuring the voltage during constant current application. An Ag probe with a tip of 5 mmR was brought into contact with a load of 0.98 N (100 gf) for an Sn plating material and a load of 0.49 N (50 gf) for an Ag plating material, and the voltage at 10 mA energization was measured. The contact resistance was calculated from the average value. The measurement was performed at the initial stage and after heating. The heating temperature and time were set to 160 ° C. for 120 hours in the case of the Sn plating material and 1000 hours at 150 ° C. in the case of the Ag plating material.

  The contact resistance was judged as normal when it was less than 3.0 mΩ before heating and less than twice the value before heating after heating.

<Durability>
After 100 reciprocating slides, it was evaluated whether the substrate or the underlying plating layer was exposed in the sliding part. The sliding part was observed with a microscope at a magnification of 450 times, and the case where the substrate and the underlying plating layer were not exposed was evaluated as ◯, and the case where the exposure was observed was evaluated as ×.

  The durability was evaluated only for the plating material including the capsule containing the lubricant and the plating material not including the capsule.

<Oxidation resistance>
In the atmosphere, heating was performed at 180 ° C. for 30 minutes, and evaluation was made as “◯” when no discoloration was observed on the surface after heating and “×” when discoloration was observed. The oxidation resistance was evaluated only for the material whose surface plating layer was Sn.

  Evaluation of oxidation resistance was performed only on the plating material including the capsule containing the rust preventive and the plating material not including the capsule.

<Sulfurization resistance>
The sample was allowed to stand at 25 ° C. for 8 hours in an atmosphere containing 10 ppm of hydrogen sulfide in the atmosphere, and evaluated as “◯” when no discoloration was observed on the surface after the test, and “×” when discoloration was observed. The evaluation of the sulfidation resistance was carried out only for the material whose surface plating layer was Ag.

  The evaluation of sulfidation resistance was performed only on the plating material including the capsule containing the sulfidation-resistant agent and the plating material not including the capsule.

<Bending workability>
90 ° bending (0.2R) was performed at right angles to the rolling direction of the conductive substrate, and the evaluation was made by cracking the plating film at the bent portion. The bending part was observed with a scanning electron microscope (SEM) at a magnification of 500 times, and the case where no crack was observed in the plating film was evaluated as “◯” and the case where the crack was observed was evaluated as “X”.

[Example 1]
Invention Examples 1 to 184, Comparative Examples 1 to 76
The chemical composition shown in Table 1 below is cast, rolled, and annealed to have a thickness of 0.2 mm pure copper (C1020: substrate A), brass (C2600: substrate B), phosphor bronze (C5210: substrate C) Corson alloy (Cu—Ni—Si: substrate D) and nickel chrome steel (Fe—Ni—Cr: substrate E) were produced. For these substrates, degreasing treatment and pickling treatment are sequentially performed as pre-plating treatment, and then a base plating layer is formed on both surfaces of the substrate, and a surface plating layer is further formed thereon. Thus, a plating material was produced. The plating conditions for forming each layer are shown in Table 2 below, and the prepared plating materials are shown in Tables 3 to 9 below.

The degreasing treatment was performed by cathodic electrolysis for 30 seconds in a degreasing solution containing 60 g / L of a cleaner 160S (manufactured by Meltex) at a liquid temperature of 60 ° C. and a current density of 2.5 A / dm ² . The pickling treatment was performed by immersing in a pickling solution containing 100 g / L of sulfuric acid at room temperature for 30 seconds.

In the formation of the surface plating layer, a plating solution obtained by adding capsules having specific gravity of 1-x and 1 + y with respect to the plating bath of 25 ° C. to the Sn plating bath or Ag plating bath shown in Table 2 below in a volume ratio of 1: 1. And plated. As the capsule, a polyamide-type outer wall was formed by an interfacial polymerization method, and a capsule containing a lubricant, a rust inhibitor, and a sulfur-resistant agent was used.
In addition, the capsule (1 + y) with a heavy specific gravity was used for the upper surface, and the capsule (1-x) with a light specific gravity was used for the lower surface.
Here, the outer wall of the polyamide system was nylon 6T, and the thickness of the wall was such that the monomer concentration was 0.7 to 0.8 mol per liter to obtain the target capsule.
Two types of capsules having the same particle size r were used.
The lubricant used was alkyl diphenyl ether (specific gravity 0.95), the sulfur-resistant agent was 2-mercaptobenzimidazole (specific gravity 1.42), and the rust inhibitor was an organic phosphate compound (specific gravity 1.05). did. These are all liquid substances or organic solvent soluble substances.
Low specific gravity capsules and high specific gravity capsules were prepared by using chloroform (specific gravity 1.48) and ethanol (specific gravity 0.79) as solvents.
Comparative Examples 8, 9, 17, 18, 27, 28, 36, 37, 46, 47, 55, 56, 65, 66, 74 and 75 are capsules having a specific gravity of either 1-x or 1 + y. It is included in the surface plating layer on one side of the substrate.

  When the capsule is exposed from the surface of the composite plating layer, the height from the plating layer surface to the capsule apex is not included in the thickness of the composite plating layer in Tables 3 to 9 above.

  About each produced plating material, the capsule density | concentration contained in the surface plating layer of both sides of a base material, a friction coefficient, contact resistance, durability, oxidation resistance, sulfidation resistance, and bending workability were implemented. These evaluation results are shown in Tables 10 to 16 below. In Tables 10-16, the location where abnormality was seen in the measurement result was underlined.

As shown in Tables 10 to 14, the plating materials of the examples of the present invention all have good contact reliability, and the concentration deviation of the capsules contained in the surface plating layers on the upper surface and the lower surface of the base material is 5% or less. . In addition, the material encapsulating the lubricant in the capsule had good lubricity and durability, the material encapsulating the anti-sulfurizing agent had good anti-sulfurity, and the material containing the anti-rust agent had good anti-oxidation.
On the other hand, as shown in Tables 15 and 16, in Comparative Examples 1, 10, 20, 29, 39, 48, 58 and 67 where the thickness of the base plating layer is thin, regardless of the type of the base plating layer, Contact resistance after heating increased. In Comparative Examples 2, 11, 21, 30, 40, 49, 59, and 68 where the thickness of the base plating layer was thick, the bending workability was inferior. In Comparative Examples 3, 12, 22, 31, 41, 50, 60, and 69 in which the surface plating layer was thin, the contact resistance and durability after heating were inferior. In Comparative Examples 4, 13, 23, 32, 42, 51, 61, and 70 in which the particle size of the capsule was small, the effect of the liquid substance contained in the capsule was inferior. In Comparative Examples 5, 14, 24, 33, 43, 52, 62 and 71 in which the capsules had a large particle size, the contact resistance and bending workability were inferior. In Comparative Examples 6, 15, 25, 34, 44, 53, 63 and 72 in which the specific gravity difference between the capsule and the plating solution is small, the capsule concentration in the surface plating layer is small, and the effect of the liquid substance contained in the capsule is inferior. It became. In Comparative Examples 7, 16, 26, 35, 45, 54, 64 and 73 where the specific gravity difference between the capsule and the plating solution is large, the capsule concentration in the surface plating layer is small, and the effect of the liquid substance contained in the capsule is inferior. It became. In Comparative Examples 8, 17, 27, 36, 46, 55, 65, and 74 produced with a plating bath that does not contain capsules having a specific gravity of 1-x, the capsule concentration contained in the surface plating layer on the lower surface of the substrate is remarkably small. The concentration deviation of the capsules contained in the surface plating layers on the upper and lower surfaces of the base material was 5% or more. In Comparative Examples 9, 18, 28, 37, 47, 56, 66, and 75 produced with a plating bath that does not contain capsules having a specific gravity of 1 + y, the capsule concentration contained in the surface plating layer on the upper surface of the substrate is extremely small. The concentration deviation of the capsules contained in the upper and lower surface plating layers was 5% or more. In Comparative Examples 19, 38, 57, and 76 in which the capsule was not included in the surface plating layer, the effect of the liquid substance contained in the capsule was inferior.

  In Tables 15 and 16, for Comparative Examples 8, 9, 17, 18, 27, 28, 36, 37, 46, 47, 55, 56, 65, 66, 74 and 75, surface plating on both surfaces of the base material There was a bias in the amount of capsules contained in the layer.

A Conductive base material having a surface plating layer on the base plating layer 1 Conductive base material 2 Base plating layer 3 Surface plating layer 4 Capsule 5 Plating bath 6 Wall material 7 Contained substance (liquid substance or organic solvent soluble substance)

Claims (12)

A composite plating material having one base plating layer on each side of the conductive substrate, and having a surface plating layer on the base plating layer,
The thickness of the base plating layer is 0.05 to 2.0 μm, the thickness t of the surface plating layer is 0.5 to 10 μm, and the surface plating layer includes a liquid substance or an organic solvent soluble substance. Capsules having an average particle diameter r of 0.01 to 1 μm, and the specific gravity of the capsule containing the liquid substance is x and y with respect to the plating solution of the surface plating layer at 25 ° C. When 0.1 to 0.3, one is 1-x, the other is 1 + y, one surface plating layer is a capsule having a specific gravity of 1-x, and the other surface plating layer is a capsule having a specific gravity of 1 + y A composite plating material characterized by comprising:   The composite plating material according to claim 1, wherein the surface plating layer is made of tin, silver, or an alloy containing these elements.   3. The composite plating according to claim 1, wherein the capsule is contained in an amount of 5.0 to 30% by volume with respect to the total volume of the surface plating layer on the surface, inside, or both of the surface plating layer. Wood.   The composite plating material according to any one of claims 1 to 3, wherein the base plating layer is made of copper, nickel, cobalt, iron, silver, or an alloy containing these elements.   The said liquid substance or organic-solvent soluble substance is a substance selected from a lubricant, a sulfidation-resistant agent, a rust preventive agent, and a discoloration prevention agent, The any one of Claims 1-4 characterized by the above-mentioned. Composite plating material.   An electrical / electronic component formed by using the composite plating material according to any one of claims 1 to 5.   A fitting-type terminal / connector, a sliding-type or rotary-type contact member or a switch, which is formed using the composite plating material according to any one of claims 1 to 5. A method for producing a composite plating material, in which a base plating layer is formed on both surfaces of a conductive substrate, and then a surface plating layer is formed on the base plating layer,
The thickness of the base plating layer is 0.05 to 2.0 μm, the thickness t of the surface plating layer is 0.5 to 10 μm, and the surface plating layer includes a liquid substance or an organic solvent soluble substance. Capsules having an average particle diameter r of 0.01 to 1 μm, and the specific gravity of the capsule containing the liquid substance is x and y with respect to the plating solution of the surface plating layer at 25 ° C. When 0.1 to 0.3, one is 1-x, the other is 1 + y, one surface plating layer is a capsule having a specific gravity of 1-x, and the other surface plating layer is a capsule having a specific gravity of 1 + y A method for producing a composite plating material, comprising:   The method for producing a composite plating material according to claim 8, wherein the surface plating layer is made of tin, silver, or an alloy containing these elements.   10. The composite plating according to claim 8, wherein the capsule is contained in an amount of 5.0 to 30% by volume with respect to the total volume of the surface plating layer on the surface, the inside, or both of the surface plating layer. A method of manufacturing the material.   The method for producing a composite plating material according to any one of claims 8 to 10, wherein the base plating layer is made of copper, nickel, cobalt, iron, silver, or an alloy containing these elements.   The said liquid substance or organic-solvent soluble substance is a substance selected from a lubricant, a sulfidation-resistant agent, a rust preventive agent, and a discoloration prevention agent, The any one of Claims 8-11 characterized by the above-mentioned. A method for producing a composite plating material.

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