JP5275504B1 - METAL MATERIAL FOR ELECTRONIC COMPONENT AND ITS MANUFACTURING METHOD, CONNECTOR TERMINAL USING THE SAME, CONNECTOR AND ELECTRONIC COMPONENT - Google Patents

Abstract

The present invention provides a metal material for electronic parts having low whisker property, low adhesion wear and high durability, and a connector terminal, connector and electronic part using the same.
A metal material for electronic parts is selected from a base material and an A constituent element group formed on the base material, the group consisting of Ni, Cr, Mn, Fe, Co, and Cu, or A lower layer composed of two or more types, one or two or more types selected from the A constituent element group formed on the lower layer, and a B constituent element group that is a group consisting of Sn and In An intermediate layer composed of seeds or two species, one or two species selected from the group B constituent elements formed on the intermediate layer, and Ag, Au, Pt, Pd, Ru, Rh, Os and Ir And an upper layer composed of an alloy of one or more selected from the group consisting of C constituent elements, the thickness of the lower layer is 0.05 μm or more and less than 5.00 μm, and the thickness of the middle layer is 0 .01 μm or more and less than 0.40 μm, and the upper layer thickness is 0.02 μm or more and 1. It is less than 00 μm.
[Selection] Figure 1

Description

  The present invention relates to a metal material for an electronic component and a method for manufacturing the same, a connector terminal using the same, a connector, and an electronic component.

  A connector that is a connection part for consumer and in-vehicle electronic devices uses a material in which a surface of brass or phosphor bronze is plated with Ni or Cu and further plated with Sn or Sn alloy. . Sn or Sn alloy plating generally requires characteristics such as low contact resistance and high solder wettability, and in recent years, it is also required to reduce insertion force when mating a male terminal and a female terminal formed by plating a plated material. ing. In addition, whiskers that are needle-like crystals that cause problems such as short circuits may occur on the plating surface in the manufacturing process, and it is necessary to suppress these whiskers well.

  On the other hand, Patent Document 1 discloses a contact base material, a base layer made of Ni or Co or an alloy of both formed on the surface of the contact base material, and Ag-Sn formed on the surface of the base layer. And an average concentration of Sn in the Ag—Sn alloy layer is less than 10% by mass, and the Sn concentration in the Ag—Sn alloy layer is from the interface with the underlayer to the Ag—Sn alloy layer. An electrical contact material is disclosed that varies with a concentration gradient that increases over the surface layer of the substrate. According to this, it is described that an electrical contact material having excellent wear resistance, corrosion resistance, and workability can be produced at a very low cost.

In Patent Document 2, at least the surface of the substrate made of Cu or a Cu alloy has a thickness containing an Ag ₃ Sn (ε phase) compound via an intermediate layer made of Ni or a Ni alloy layer on the surface of the substrate. A material for electric / electronic parts is disclosed, in which a surface layer composed of a Sn layer or a Sn alloy layer of 0.5 to 20 μm is formed. And according to this, the surface layer has a lower melting point than Sn, excellent solderability, no whisker, high joint strength of the joint formed after soldering, and high joint strength. This is suitable as a lead material because it does not easily degrade over time, and even when used in a high temperature environment, the increase in contact resistance is suppressed, and the connection reliability with the counterpart material is not reduced. Therefore, it is described that the object is to provide a material for an electric / electronic component suitable as a contact material, a method for manufacturing the same, and an electric / electronic component using the material.

  Patent Document 3 discloses a covering material comprising a conductive base material and a coating layer formed on the base material, wherein the coating layer is an intermetallic compound of Sn and a noble metal at least on the surface side. The coating | covering material characterized by including is disclosed. According to this, a coating material having a low contact resistance, a low friction coefficient, effective in reducing the insertion force, excellent in oxidation resistance and stable over a long period of time, and its It describes that it aims to provide a manufacturing method.

JP-A-4-370613 JP 11-350189 A JP 2005-126763 A

However, in the technique described in Patent Document 1, the relationship between the reduction in insertion force and the presence or absence of whisker generation, which have been required in recent years, has not been clarified. Moreover, since the average concentration of Sn in the Ag—Sn alloy layer is less than 10% by mass and the proportion of Ag in the Ag—Sn alloy layer is considerably large, the evaluation by the present inventors shows that chlorine gas, sulfurous acid gas, hydrogen sulfide, etc. The gas corrosion resistance to the gas was not sufficient.
Moreover, in the technique described in Patent Document 2, it is a surface layer composed of a Sn layer or Sn alloy layer having a thickness of 0.5 to 20 μm containing an Ag ₃ Sn (ε phase) compound. There was a region where the insertion force could not be lowered sufficiently with this surface layer thickness. Furthermore, it is described that the content of Ag ₃ Sn (ε phase) in the surface layer composed of the Sn layer or the Sn alloy layer is 0.5 to 5% by mass in terms of Ag, and from the Sn layer or the Sn alloy layer. In the evaluation by the present inventors, whisker was generated because the ratio of Sn in the surface layer formed was large and the thickness of the surface layer made of Sn layer or Sn alloy layer was also thick, and the resistance to fine sliding wear was not sufficient. Heat resistance and solder wettability were not sufficient.
In the technique described in Patent Document 3, the coating layer contains an intermetallic compound of Sn and a noble metal. The thickness of the intermetallic compound of Sn and the noble metal (Ag ₃ Sn) is preferably 1 μm or more and 3 μm. According to the following evaluations by the present inventors, the insertion force could not be lowered sufficiently with this thickness.
As described above, the metal material for electronic parts having the conventional Sn—Ag alloy / Ni base plating structure still has a problem that the insertion force cannot be sufficiently lowered and whiskers are generated. In addition, it is difficult to make the specification sufficiently satisfactory in terms of durability (heat resistance, solder wettability, fine sliding wear resistance, and gas corrosion resistance), and it has not been clarified.
The present invention has been made in order to solve the above-mentioned problems. A metal material for electronic parts having low whisker properties, low adhesion wear and high durability, and a connector terminal, a connector and an electronic component using the same. The issue is to provide. Adhesive wear refers to a wear phenomenon that occurs due to the fact that an adhesive portion constituting a real contact area between solids is sheared by frictional motion. When this adhesion wear increases, the insertion force when the male terminal and the female terminal are fitted together increases.

  As a result of intensive studies, the inventors provided a lower layer, an intermediate layer, and an upper layer in order on the base material, using a predetermined metal for the lower layer, the intermediate layer, and the upper layer, and having a predetermined thickness and composition, It has been found that a metal material for electronic parts having low whisker properties, low adhesion wear properties and high durability can be produced.

  In one aspect, the present invention completed based on the above knowledge is selected from a base material and an A constituent element group which is a group consisting of Ni, Cr, Mn, Fe, Co and Cu formed on the base material. B layer which is a group consisting of Sn and In, and a lower layer composed of one or two or more selected, one or more selected from the A constituent element group formed on the lower layer, and An intermediate layer composed of one or two elements selected from the element group, one or two elements selected from the B constituent element group formed on the intermediate layer, and Ag, Au, Pt, Pd And an upper layer made of an alloy of one or more selected from the C constituent element group, which is a group consisting of Ru, Rh, Os, and Ir, and the lower layer has a thickness of 0.05 μm or more. Less than 00 μm, and the thickness of the intermediate layer is 0.01 μm or more and 0.4 Less than [mu] m, the upper layer of a thickness of less than 0.02 [mu] m 1.00 .mu.m, low whisker resistance, a metal material for electronic parts having a low adhesive wear resistance and high durability.

  In one embodiment of the metal material for electronic parts of the present invention, the minimum thickness (μm) of the upper layer is 50% or more of the thickness (μm) of the upper layer.

  In another embodiment of the metal material for electronic parts according to the present invention, the maximum value (μm) of the height difference (μm) between adjacent peaks and valleys in the interface profile between the upper layer and the middle layer is the thickness (μm) of the upper layer. Of 50% or less.

  In still another embodiment of the metal material for electronic components of the present invention, the surface of the upper layer has a total atomic concentration of B constituent elements (at%) ≧ a total atomic concentration of C constituent elements (at%), and O The region where the atomic concentration (at%) of ≧ 10 at% exists is 0.02 μm or less.

  In still another embodiment of the metal material for electronic parts according to the present invention, the upper layer contains 10 to 50 at% of the metal of the B constituent element group.

  In still another embodiment of the metal material for electronic parts of the present invention, a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn exists in the upper layer.

In still another embodiment of the metal material for electronic parts of the present invention, an ε (epsilon) phase that is Ag ₃ Sn exists in the upper layer.

In still another embodiment of the metal material for electronic parts of the present invention, a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn and ε (Ag ₃ Sn) in the upper layer. Epsilon) phase.

In still another embodiment of the metal material for electronic parts of the present invention, only the ε (epsilon) phase that is Ag ₃ Sn exists in the upper layer.

In still another embodiment of the metal material for electronic parts of the present invention, an ε (epsilon) phase that is Ag ₃ Sn and βSn that is a Sn single phase are present in the upper layer.

In still another embodiment of the metal material for electronic parts of the present invention, a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn and ε (Ag ₃ Sn) in the upper layer. (Epsilon) phase and βSn which is a single Sn phase.

  In still another embodiment of the metal material for electronic parts of the present invention, the intermediate layer contains 35 at% or more of the metal of the B constituent element group.

In still another embodiment of the metal material for electronic parts of the present invention, Ni ₃ Sn ₄ and Ni ₃ Sn ₂ are present in the intermediate layer.

In still another embodiment of the metal material for electronic components of the present invention, Ni ₃ Sn ₄ and βSn that is a Sn single phase are present in the intermediate layer.

  In still another embodiment of the metal material for electronic parts of the present invention, the thickness ratio of the upper layer to the middle layer is upper layer: middle layer = 9: 1 to 3: 7.

  In still another embodiment of the metal material for electronic components of the present invention, C, S, and O are each 2 at% or less from the upper layer to the middle layer excluding the range of 0.03 μm from the outermost surface of the upper layer. contains.

  In still another embodiment, the metal material for electronic parts according to the present invention has a hardness obtained by measuring a dent on a surface of the upper layer with a load of 10 mN by an ultra micro hardness test. The indentation hardness of the surface is 1000 MPa or more.

  In still another embodiment, the metal material for electronic parts according to the present invention has a hardness obtained by measuring a dent on a surface of the upper layer with a load of 10 mN by an ultra micro hardness test. The indentation hardness of the surface is 10000 MPa or less.

  In still another embodiment of the metal material for electronic parts according to the present invention, the arithmetic average height (Ra) of the surface of the upper layer is 0.3 μm or less.

  In still another embodiment of the metal material for electronic parts according to the present invention, the maximum height (Rz) of the surface of the upper layer is 3 μm or less.

  In still another embodiment of the metal material for electronic parts according to the present invention, the upper layer, the middle layer, and the lower layer are formed of one or more selected from the group A constituent elements on the substrate. Then, one or two types selected from the C constituent element group are formed, and then one or two or more types selected from the B constituent element group are formed, and the A constituent element group Each element of the B constituent element group and the C constituent element group is formed by diffusing.

  In still another embodiment of the metal material for electronic parts of the present invention, the diffusion is performed by heat treatment.

  In still another embodiment of the metal material for electronic parts of the present invention, the heat treatment is performed at a temperature equal to or higher than the melting point of the metal of the B constituent element group, and one or two selected from the B constituent element group and One or more alloy layers selected from the A constituent element group, one or two selected from the B constituent element group, and one or two kinds selected from the C constituent element group The above alloy layer is formed.

  In still another embodiment of the metal material for electronic parts according to the present invention, the metal of the A constituent element group is 50 mass% or more in total of Ni, Cr, Mn, Fe, Co, Cu, and further, B, P, 1 type or 2 types or more selected from the group which consists of Sn and Zn are included.

  In still another embodiment of the metal material for electronic parts of the present invention, the total of metals of the B constituent element group is 50 mass% or more, and the remaining alloy components are Ag, As, Au, Bi, It consists of 1 type, or 2 or more types of metals selected from the group which consists of Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Sb, W and Zn.

  In another embodiment of the metal material for electronic parts of the present invention, the metal of the C constituent element group is 50 mass% or more in total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, One or more metals selected from the group consisting of Bi, Cd, Co, Cu, Fe, In, Mn, Mo, Ni, Pb, Sb, Se, Sn, W, Tl and Zn. Consists of.

  In still another embodiment of the metal material for electronic parts according to the present invention, the lower layer has a Vickers hardness of Hv300 or more in the cross section.

  In yet another embodiment, the metal material for electronic parts according to the present invention has a hardness obtained by measuring a dent on a cross section of the lower layer with a load of 10 mN by an ultra micro hardness test. The indentation hardness of the cross section is 1500 MPa or more.

  In still another embodiment of the metal material for electronic parts according to the present invention, the Vickers hardness of the cross section of the lower layer is Hv 1000 or less.

  In yet another embodiment, the metal material for electronic parts according to the present invention has a hardness obtained by measuring a dent on a cross section of the lower layer with a load of 10 mN by an ultra micro hardness test. The indentation hardness of the cross section is 10000 MPa or less.

In still another embodiment of the metal material for electronic parts according to the present invention, the intermediate layer is composed of Ni ₃ Sn and Ni ₃ Sn ₂ .

In still another embodiment of the metal material for electronic parts according to the present invention, the intermediate layer is made of Ni ₃ Sn ₂ .

In still another embodiment of the metal material for electronic parts according to the present invention, the intermediate layer is made of Ni ₃ Sn ₄ .

  In still another embodiment, the metal material for electronic parts according to the present invention further includes a layer composed of an alloy of a metal of the A constituent element group and a metal of the C constituent element group between the lower layer and the middle layer. .

In still another embodiment of the metal material for electronic parts according to the present invention, P adheres to the surface of the upper layer, and the adhesion amount of P is 1 × 10 ⁻¹¹ to 4 × 10 ⁻⁸ mol / cm ^2. It is.

In still another embodiment of the metal material for electronic parts according to the present invention, N is further adhered to the surface of the upper layer, and the amount of N deposited is 2 × 10 ⁻¹² to 8 × 10 ⁻⁹ mol / cm. ² .

  In still another embodiment of the metal material for electronic parts of the present invention, when the upper layer is analyzed by XPS, the photoelectron detection intensity caused by the 2S orbital electrons of P detected is I (P2s), and the 1S orbital of N When the photoelectron detection intensity due to electrons is I (N1s), 0.1 ≦ I (P2s) / I (N1s) ≦ 1 is satisfied.

  In still another embodiment of the metal material for electronic parts of the present invention, when the upper layer is analyzed by XPS, the photoelectron detection intensity caused by the 2S orbital electrons of P detected is I (P2s), and the 1S orbital of N When the photoelectron detection intensity due to electrons is I (N1s), 1 <I (P2s) / I (N1s) ≦ 50 is satisfied.

In another aspect of the present invention, the base material and one or two selected from the A constituent element group, which is a group consisting of Ni, Cr, Mn, Fe, Co, and Cu, formed on the base material. A lower layer composed of seeds or more, one or more selected from the A constituent element group formed on the lower layer, and a B constituent element group which is a group consisting of Sn and In A middle layer composed of one or two species, one or two species selected from the B constituent element group formed on the middle layer, Ag, Au, Pt, Pd, Ru, Rh, Os And an upper layer composed of an alloy of one or more selected from the C constituent element group which is a group consisting of Ir and Ir, the following general formulas [1] and [2] At least one phosphoric acid ester represented by the following general formulas [3] and [4] Is at least one method of manufacturing the metal material for electronic component of the present invention to surface treatment with a phosphate ester-based liquid containing selected cyclic organic compounds represented.
(In the formulas [1] and [2], R ₁ and R ₂ each represent a substituted alkyl, and M represents hydrogen or an alkali metal.)
(In the formulas [3] and [4], R ₁ represents hydrogen, alkyl, or substituted alkyl, R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl, R ₃ represents an alkali metal or hydrogen, R ₄ represents —SH, an amino group substituted with an alkyl group or an aryl group, or alkyl-substituted imidazolylalkyl, and R ₅ and R ₆ represent —NH ₂ , —SH or —SM (M represents an alkali metal). Represents.)

  In one embodiment of the method for producing a metal material for electronic parts according to the present invention, the surface treatment with the phosphate ester solution is performed by applying a phosphate ester solution to the surface of the upper layer.

  In another embodiment of the method for producing a metal material for an electronic component according to the present invention, the surface treatment with the phosphate ester solution is performed by immersing the metal material after the formation of the upper layer in the phosphate ester solution, and This is performed by electrolysis using the formed metal material as an anode.

  In still another aspect of the present invention, there is provided a connector terminal using the metal material for electronic parts of the present invention as a contact portion.

  In still another aspect, the present invention is a connector using the connector terminal of the present invention.

  In still another aspect, the present invention is an FFC terminal using the metal material for electronic parts of the present invention as a contact portion.

  In still another aspect, the present invention is an FPC terminal using the metal material for electronic parts of the present invention as a contact portion.

  In still another aspect, the present invention is an FFC using the FFC terminal of the present invention.

  In still another aspect, the present invention is an FPC using the FPC terminal of the present invention.

  In still another aspect of the present invention, an electronic component using the metal material for an electronic component of the present invention as an external connection electrode.

  In yet another aspect of the present invention, the metal material for electronic components of the present invention is provided with a female terminal connection portion on one side of a mounting portion for mounting on the housing and a substrate connection portion on the other side, and the substrate connection portion. Is an electronic component used for a press-fit terminal that is press-fitted into a through-hole formed in the substrate and attached to the substrate.

  ADVANTAGE OF THE INVENTION According to this invention, the metal material for electronic components which has low whisker property, low adhesive wear property, and high durability, a connector terminal using the same, a connector, and an electronic component can be provided.

It is a schematic diagram which shows the structure of the metal material for electronic components which concerns on embodiment of this invention. It is an XPS analysis figure of the metal material for electronic components which concerns on this invention. It is a related figure of the post-treatment liquid component adhesion amount and the XPS detection intensity of the metal material for electronic parts according to the present invention. It is a HAADF (high angle scattering dark field) image schematic diagram of STEM (scanning electron microscope) of the metal material for electronic components according to the present invention. It is a SEM (scanning electron microscope) line-analysis result schematic diagram of the metal material for electronic parts concerning the present invention. It is a state diagram of SnAg. It is a state diagram of SnNi.

  Hereinafter, the metal material for electronic components according to the embodiment of the present invention will be described. As shown in FIG. 1, the electronic component metal material 10 according to the embodiment has a lower layer 12 formed on a substrate 11, an intermediate layer 13 formed on the lower layer 12, and an upper layer 14 formed on the intermediate layer 13. Yes.

<Configuration of metal materials for electronic parts>
(Base material)
Although it does not specifically limit as the base material 11, For example, metal base materials, such as copper and a copper alloy, Fe-type material, stainless steel, titanium and a titanium alloy, aluminum, and an aluminum alloy, can be used. Alternatively, a metal base and a resin layer may be combined. Examples of composites of metal layers and resin layers include electrode portions on FPC or FFC substrates.

(Upper layer)
The upper layer 14 is composed of one or two selected from the group consisting of Sn and In which is a group consisting of B, and a group C consisting of a group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os and Ir It is necessary to be comprised with the alloy with 1 type, or 2 or more types selected from the group.
Sn and In are oxidizable metals, but are relatively soft among metals. Therefore, even if an oxide film is formed on the Sn and In surfaces, for example, when a male terminal and a female terminal are mated using a metal material for electronic parts as a contact material, the oxide film is easily scraped, and the contact becomes metal-to-metal. Therefore, low contact resistance is obtained.
Sn and In are excellent in gas corrosion resistance against gases such as chlorine gas, sulfurous acid gas, and hydrogen sulfide gas. For example, upper layer 14 is inferior in gas corrosion resistance, lower layer 12 is inferior in gas corrosion resistance, When copper and a copper alloy inferior in gas corrosion resistance are used for the base material 11, there exists a function which improves the gas corrosion resistance of the metal material for electronic components. For Sn and In, Sn is preferable because In is strictly regulated based on the technical guidelines for preventing health problems of the Ministry of Health, Labor and Welfare.
Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir are characterized by relatively heat resistance among metals. Therefore, it suppresses that the composition of the base material 11, the lower layer 12, and the middle layer 13 diffuses to the upper layer 14 side, and improves heat resistance. Further, these metals form a compound with Sn or In in the upper layer 14 to suppress the formation of an oxide film of Sn or In and improve solder wettability. Among Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, Ag is more desirable from the viewpoint of conductivity. Ag has high conductivity. For example, when Ag is used for high frequency signal applications, the impedance resistance is lowered due to the skin effect.
The thickness of the upper layer 14 needs to be 0.02 μm or more and less than 1.00 μm. When the thickness of the upper layer 14 is less than 0.02 μm, the composition of the base material 11 and the lower layer 12 is easily diffused to the upper layer 14 side, and heat resistance and solder wettability are deteriorated. Further, the upper layer is worn by fine sliding, and the lower layer 12 having a high contact resistance is easily exposed, so the resistance to fine sliding wear is poor, and the contact resistance is likely to increase by fine sliding. Furthermore, since the lower layer 12 having poor gas corrosion resistance is easily exposed, the gas corrosion resistance is also poor, and when the gas corrosion test is performed, the appearance is discolored. On the other hand, when the thickness of the upper layer 14 is 1.00 μm or more, the thin film lubrication effect by the hard base material 11 or the lower layer 12 is lowered and adhesion wear is increased. In addition, mechanical durability is lowered, and plating scraping is likely to occur.
The upper layer 14 preferably contains 10 to 50 at% of the metal of the B constituent element group. When the metal of the B constituent element group is less than 10 at%, for example, when the metal of the C constituent element group is Ag, the gas corrosion resistance is poor, and when the gas corrosion test is performed, the appearance may be discolored. On the other hand, if the metal of the B constituent element group exceeds 50 at%, the proportion of the metal of the B constituent element group in the upper layer 14 increases, and adhesion wear increases, and whiskers are likely to occur. Furthermore, there are cases where the resistance to fine sliding wear is poor.
The upper layer 14 preferably has a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn. The presence of the ζ (zeta) phase improves the gas corrosion resistance, and the appearance hardly changes even when a gas corrosion test is performed.
It is preferable that a ζ (zeta) phase and an ε (epsilon) phase that is Ag ₃ Sn exist in the upper layer 14. Due to the presence of the ε (epsilon) phase, the coating becomes harder and the adhesive wear is reduced as compared with the case where only the ζ (zeta) phase is present in the upper layer 14. Moreover, gas corrosion resistance improves because Sn ratio of the upper layer 14 increases.
It is preferable that only the ε (epsilon) phase that is Ag ₃ Sn exists in the upper layer 14. The existence of the ε (epsilon) phase alone in the upper layer 14 makes the coating harder and harder than the case where the ζ (zeta) phase and the ε (epsilon) phase of Ag ₃ Sn exist in the upper layer 14. Wear is reduced. Further, the higher the Sn ratio of the upper layer 14, the better the gas corrosion resistance.
It is preferable that an ε (epsilon) phase that is Ag ₃ Sn and βSn that is a Sn single phase exist in the upper layer 14. By the presence of ε (epsilon) phase that is Ag ₃ Sn and βSn that is Sn single phase, the upper layer has a higher Sn ratio than the case where only the ε (epsilon) phase is present in the upper layer 14. As a result, the gas corrosion resistance is improved.
The upper layer 14 may have a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn, an ε (epsilon) phase that is Ag ₃ Sn, and βSn that is a single Sn phase. preferable. The presence of the ζ (zeta) phase, the ε (epsilon) phase that is Ag ₃ Sn, and βSn that is the Sn single phase improves the gas corrosion resistance, and the appearance changes even when a gas corrosion test is performed. It is difficult to wear and adhesion wear decreases. This composition occurs by diffusion and is not an equilibrium structure.
The upper layer 14 should not be present by βSn alone. In the presence of βSn alone, adhesion wear is large, whiskers are generated, and heat resistance, fine sliding wear resistance and the like deteriorate.

(Middle layer)
Between the lower layer 12 and the upper layer 14, one or more selected from the group A constituent elements that are a group consisting of Ni, Cr, Mn, Fe, Co and Cu, and a group consisting of Sn and In It is necessary that the middle layer 13 composed of one or two selected from the B constituent element group is formed with a thickness of 0.01 μm or more and less than 0.40 μm. Sn and In are excellent in gas corrosion resistance against gases such as chlorine gas, sulfurous acid gas, and hydrogen sulfide gas. For example, Ni is inferior in gas corrosion resistance in the lower layer 12, and copper and copper inferior in gas corrosion resistance in the base material 11. When an alloy is used, it has the function of improving the gas corrosion resistance of the metal material for electronic parts. Ni, Cr, Mn, Fe, Co, and Cu are hard to cause adhesive wear because the film is harder than Sn and In, and prevent the constituent metals of the base material 11 from diffusing into the upper layer 14. Improve durability, such as suppressing property deterioration and solder wettability degradation.
When the thickness of the middle layer 13 is 0.01 μm or more, the coating becomes hard and adhesion wear decreases. On the other hand, when the thickness of the middle layer 13 is 0.40 μm or more, the bending workability is lowered, the mechanical durability is lowered, and plating scraping may occur.
Among Sn and In, Sn is preferable because In is strictly regulated based on the technical guideline for preventing health problems of the Ministry of Health, Labor and Welfare. Of Ni, Cr, Mn, Fe, Co and Cu, Ni is preferable. This is because Ni is hard and adhesion wear hardly occurs, and sufficient bending workability is obtained.
In the middle layer 13, the B group element group metal is preferably 35 at% or more. If the Sn content is 35 at% or more, the film becomes hard and adhesion wear may be reduced.
The middle layer 13 may be composed of Ni ₃ Sn and Ni ₃ Sn ₂ , or may be composed of Ni ₃ Sn ₂ or Ni ₃ Sn ₄ alone. The presence of Ni ₃ Sn, Ni ₃ Sn ₂ and Ni ₃ Sn ₄ may improve heat resistance and solder wettability.
It is preferable that Ni ₃ Sn ₄ and βSn which is a Sn single phase exist in the middle layer 13. The presence of these may improve the heat resistance and solder wettability as compared with the case where Ni ₃ Sn ₄ and Ni ₃ Sn ₂ exist.

(Relationship between upper layer thickness and upper layer minimum thickness)
It is preferable that the minimum thickness (μm) of the upper layer 14 satisfies 50% or more of the thickness (μm) of the upper layer 14. When the minimum thickness of the upper layer 14 is less than 50% of the thickness of the upper layer 14, the surface roughness of the upper layer 14 is rough, the contact resistance is high, the solder is difficult to wet, and Ni having poor gas corrosion resistance is exposed on the surface. Heat resistance, solder wettability, and gas corrosion resistance may deteriorate.
Here, the place where the relationship between the thickness of the upper layer 14 and the minimum thickness of the upper layer 14 is grasped is the average cross section of the portion that exhibits the effect of the coating of the present invention. A portion where the film is normally formed in the normal surface profile of the material (excluding oil pits, etch pits, scratches, marks, and other surface defect portions) is shown. Needless to say, it does not include a deformed portion by press working before and after film formation.

(Relationship between the thickness of the upper layer and the maximum height difference between adjacent peaks and valleys in the interface profile between the upper layer and the middle layer)
It is preferable that the maximum value (μm) of the height difference (μm) between adjacent peaks and valleys in the interface profile between the upper layer 14 and the middle layer 13 satisfies 50% or less of the thickness (μm) of the upper layer 14. When the maximum height difference between adjacent peaks and valleys of the interface profile between the upper layer 14 and the middle layer 13 exceeds 50% of the thickness of the upper layer 14, the middle layer 13 is present near the upper layer 14, and the contact resistance is reduced. Ni, which is high and hardly wets the solder and is inferior in gas corrosion resistance, is likely to be exposed on the surface, so that heat resistance, solder wettability, and gas corrosion resistance may deteriorate.
The microscopic distribution of the thickness of the upper layer 14 and the interface profile between the upper layer 14 and the middle layer 13 can be controlled by the film forming conditions of the lower layer 12, the middle layer 13, and the upper layer 14. By adjusting the plating conditions (metal concentration, additive, cathode current density, liquid stirring, etc.) during film formation, the above “relationship between upper layer thickness and upper layer minimum thickness” and the above “upper layer thickness and upper layer” The film is smoothly electrodeposited so as to satisfy the relationship between the height of the height difference between adjacent peaks and valleys of the interface profile between the intermediate layer and the intermediate layer.

(Ratio and composition of thickness of upper layer and middle layer)
The thickness ratio of the upper layer 14 and the middle layer 13 is preferably upper layer: middle layer = 9: 1 to 3: 7. When the ratio of the upper layer 14 exceeds 9, the thin film lubrication effect is reduced to the hard base material 11, the lower layer 12, and the middle layer 13 that is harder than the upper layer 14, and adhesion wear increases. On the other hand, if the ratio of the upper layer 14 is less than 3, the contact resistance is high, the solder is difficult to get wet, and Ni, which is inferior in gas corrosion resistance, is likely to be exposed on the surface, so heat resistance, solder wettability, fine sliding wear resistance In addition, gas corrosion resistance may deteriorate.
Moreover, it is preferable that C, S, and O are each contained in 2 at% or less from the upper layer 14 to the middle layer 13 excluding the range of 0.03 μm from the outermost surface of the upper layer 14. When C, S, and O are more than 2 at%, these eutectoid elements may be gasified when heat treatment is performed, and a uniform alloy film may not be formed.

(Underlayer)
Between the base material 11 and the upper layer 14, a lower layer 12 composed of one or more selected from the A constituent element group which is a group consisting of Ni, Cr, Mn, Fe, Co, and Cu is formed. There is a need to. By forming the lower layer 12 using one or two or more metals selected from the group A constituent elements which are a group consisting of Ni, Cr, Mn, Fe, Co and Cu, thin film lubrication is achieved by forming the hard lower layer 12. The effect is improved and adhesion wear is reduced, and the lower layer 12 prevents the constituent metals of the base material 11 from diffusing into the upper layer 14 and improves heat resistance, solder wettability, and the like.
The thickness of the lower layer 12 needs to be 0.05 μm or more. When the thickness of the lower layer 12 is less than 0.05 μm, the thin film lubricating effect by the hard lower layer is lowered, and adhesion wear increases. The constituent metal of the base material 11 is easily diffused into the upper layer 14, and heat resistance and solder wettability are deteriorated. On the other hand, the thickness of the lower layer 12 needs to be less than 5.00 μm. Bending workability is poor when the thickness is 5.00 μm or more.

  On the surface of the upper layer 14, the total atomic concentration of B constituent elements (at%) ≧ the total atomic concentration of C constituent elements (at%) and the region where the atomic concentration of O (at%) ≧ 10 at% is 0.02 μm It is preferably present in: Since Sn, which is a B constituent element, has an affinity for O, the surface binds to O after Sn plating. This region exists because Sn oxide formed by this bonding does not cause alloying of SgAg even when heat treatment is performed, and maintains the state before the heat treatment. However, if this region exceeds 0.02 μm, contact resistance and solder wettability may deteriorate.

  Between the lower layer 12 and the middle layer 13, a layer made of an alloy of a metal of the A constituent element group and a metal of the C constituent element group may be further provided. As the layer, for example, a Ni—Ag alloy layer is preferable. If such a layer is formed between the lower layer 12 and the middle layer 13, the constituent metal of the base material 11 is further prevented from diffusing into the upper layer 14 to improve heat resistance, solder wettability, and the like. .

(Group A element group)
The metal of the A constituent element group is 50 mass% or more in total of Ni, Cr, Mn, Fe, Co, and Cu, and further includes one or more selected from the group consisting of B, P, Sn, and Zn But it ’s okay. When the alloy composition of the lower layer 12 has such a configuration, the lower layer 12 is further cured, so that the thin film lubrication effect is further improved and adhesion wear is further reduced. It may further prevent the metal from diffusing into the upper layer, and may improve durability such as heat resistance and solder wettability.

(B element group)
The B group element group metals are 50 mass% or more in total of Sn and In, and the remaining alloy components are Ag, As, Au, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, You may consist of 1 type, or 2 or more types of metals selected from the group which consists of Sb, W, and Zn. These metals may further reduce adhesion wear, suppress whisker generation, and improve durability such as heat resistance and solder wettability.

(C element group)
The metal of the C constituent element group is 50 mass% or more in total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, and the remaining alloy components are Bi, Cd, Co, Cu, Fe, In, Mn, You may consist of 1 type, or 2 or more types of metals selected from the group which consists of Mo, Ni, Pb, Sb, Se, Sn, W, Tl, and Zn. These metals may further reduce adhesion wear, suppress whisker generation, and improve durability such as heat resistance and solder wettability.

(Diffusion processing)
The upper layer 14, the middle layer 13 and the lower layer 12 are formed on the base material 11 with one or more selected from the A constituent element group, and then one or two selected from the C constituent element group are formed. After forming a film, one or more types selected from the B constituent element group are formed, and each element of the A constituent element group, the B constituent element group, and the C constituent element group is diffused to form each film. May be. For example, when the metal of the B constituent element group is Sn and the metal of the C constituent element group is Ag, the diffusion of Ag into Sn is fast, and an Sn—Ag alloy layer is formed by natural diffusion. By forming the alloy layer, the adhesion force of Sn can be further reduced, and the low whisker property and durability can be further improved.

(Heat treatment)
After the upper layer 14 is formed, heat treatment may be performed for the purpose of further suppressing adhesion wear and further improving the low whisker property and durability. The heat treatment makes it easier for the metal of the B constituent element group and the metal of the C constituent element group of the upper layer 14, the metal of the A constituent element group of the middle layer 13 and the metal of the B constituent element group to form an alloy layer, and Sn adhesion force The whisker property and durability can be further improved.
In addition, about this heat processing, process conditions (temperature x time) can be selected suitably. Further, this heat treatment is not particularly required. When heat treatment is performed, the temperature of the B constituent element group metal is higher than the melting point of the B constituent element group metal, the B constituent element group metal of the upper layer 14 and the C constituent element group metal, and the middle layer 13 of the A constituent element group metal. It becomes easier to form an alloy layer with the metal of the B constituent element group.

(Post-processing)
After the heat treatment is performed on the upper layer 14 or on the upper layer 14, a post-treatment may be performed for the purpose of further reducing adhesion wear and improving low whisker property and durability. The post-treatment improves lubricity, further reduces adhesion wear, suppresses oxidation of the upper layer 14, and improves durability such as heat resistance and solder wettability. Specific post-treatment includes phosphate treatment, lubrication treatment, silane coupling treatment, etc. using an inhibitor. In addition, about this heat processing, process conditions (temperature x time) can be selected suitably. Further, this post-processing is not particularly required.

  As post-processing, the surface of the upper layer 14 is performed using an aqueous solution (referred to as a phosphate ester-based solution) containing one or more phosphate esters and one or more cyclic organic compounds. It is desirable. The phosphoric acid ester added to the phosphoric acid ester system liquid functions as an antioxidant and a lubricant for plating. The phosphate ester used in the present invention is represented by the general formulas [1] and [2]. Preferable examples of the compound represented by the general formula [1] include lauryl acidic phosphoric acid monoester. Preferred examples of the compound represented by the general formula [2] include lauryl acid diphosphate.

(In the formulas [1] and [2], R ₁ and R ₂ each represent a substituted alkyl, and M represents hydrogen or an alkali metal.)

  The cyclic organic compound added to the phosphate ester-based liquid functions as an antioxidant for plating. A group of cyclic organic compounds used in the present invention is represented by general formulas [3] and [4]. Preferred examples of the cyclic organic compound group represented by the general formulas [3] and [4] include mercaptobenzothiazole, mercaptobenzothiazole Na salt, mercaptobenzothiazole K salt, benzotriazole, 1-methyltriazole, Examples include tolyltriazole and triazine compounds.

(In the formulas [3] and [4], R ₁ represents hydrogen, alkyl, or substituted alkyl, R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl, R ₃ represents an alkali metal or hydrogen, R ₄ represents —SH, an amino group substituted with an alkyl group or an aryl group, or alkyl-substituted imidazolylalkyl, and R ₅ and R ₆ represent —NH ₂ , —SH or —SM (M represents an alkali metal). Represents.)

More preferably, the treatment is performed so that both P and N are present on the surface of the upper layer 14 after the post-treatment. If P is not present on the plating surface, the solderability is likely to deteriorate, and the lubricity of the plating material also deteriorates. On the other hand, if N is not present on the Sn or Sn alloy plating surface, the contact resistance of the plating material may easily increase in a high temperature environment.
Furthermore, in the present invention, when P adheres to the surface of the upper layer 14, if the adhesion amount is 1 × 10 ⁻¹¹ to 4 × 10 ⁻⁸ mol / cm ² , the solderability is not further deteriorated and lubrication is performed. This is preferable because the property is better and the increase in contact resistance is less. Further, when N is further adhered to the surface of the upper layer 14, it is more preferable that the amount of adhesion is 2 × 10 ⁻¹² to 8 × 10 ⁻⁹ mol / cm ² . When the adhesion amount of P is less than 1 × 10 ⁻¹¹ mol / cm ² , the solder wettability tends to deteriorate, and when the adhesion amount exceeds 4 × 10 ⁻⁸ mol / cm ² , the contact resistance increases. May occur.
Further, if the photoelectron detection intensity by the transition of P 2S orbital electrons detected when the upper layer 14 is analyzed by the XPS method is I (P2s), and the photoelectron detection intensity by the transition of 1S orbital electrons of N is I (N1s), When the relationship of 0.1 ≦ I (P2s) / I (N1s) ≦ 1 is satisfied, the contact resistance and solderability of the plating material may not easily deteriorate in a high temperature environment. When the value of I (P2s) / I (N1s) is less than 0.1, the deterioration prevention function such as contact resistance is not sufficient. When the value exceeds 1, the initial contact resistance is slightly higher. As will be described next, the dynamic friction coefficient of the plating material may be small. In this case, it is more preferable that I (P2s) and I (N1s) satisfy the relationship of 0.3 ≦ I (P2s) / I (N1s) ≦ 0.8.
Similarly to the above, I (P2s) is the photoelectron detection intensity due to the transition of P 2S orbital electrons detected when the upper layer 14 is analyzed by the XPS method, and I (N1s) is the photoelectron detection intensity due to the transition of N 1S orbital electrons. Then, when the relationship of 1 <I (P2s) / I (N1s) ≦ 50 is satisfied, the dynamic friction coefficient of the plating material may be decreased, and the insertion force of the terminals and connectors may be decreased. When the value of I (P2s) / I (N1s) is 1 or less, the insertion force is slightly higher. When the value exceeds 50, the insertion force is lowered, but the initial contact resistance is increased, and the initial solder is increased. There is a case that the attachment is also deteriorated. In this case, it is more preferable that I (P2s) and I (N1s) satisfy the relationship of 5 <I (P2s) / I (N1s) ≦ 40.

The concentration of the phosphate ester for obtaining the adhesion amount of the post-treatment liquid component on the surface of the upper layer 14 of the present invention is 0.1 to 10 g / L, preferably 0.5 to 5 g / L. On the other hand, the concentration of the cyclic organic compound is 0.01 to 1.0 g / L, preferably 0.05 to 0.6 g / L, with respect to the total volume of the treatment liquid.
Phosphate-based liquid is an aqueous solution containing the above-mentioned components, but when the temperature of the solution is heated to 40 to 80 ° C., the emulsification of the components into water proceeds more rapidly, and the material after further treatment can be easily dried. become.
The surface treatment may be performed by applying a phosphate ester-based liquid to the surface of the upper layer 14 after the upper layer 14 is formed. Examples of the application method include spray coating, flow coating, dip coating, roll coating, and the like. From the viewpoint of productivity, dip coating or spray coating is preferred. On the other hand, as another treatment method, the metal material after the formation of the upper layer 14 may be immersed in a phosphoric acid ester solution and electrolyzed using the metal material as an anode. The metal material treated by this method has an advantage that the contact resistance in a high temperature environment is less likely to increase.

  The surface treatment with the phosphoric acid ester-based liquid described so far may be performed either after the upper layer 14 is formed or after the reflow treatment after the upper layer 14 is formed. The surface treatment is not particularly limited in time, but is preferably performed in a series of steps from an industrial viewpoint.

<Characteristics of metal materials for electronic parts>
It is preferable that the indentation hardness of the surface of the upper layer 14 is 1000 MPa or more, which is the hardness obtained by measuring the surface of the upper layer 14 by making a dent with a load of 10 mN by an ultra micro hardness test. When the indentation hardness is 1000 MPa or more, the thin film lubricating effect by the hard upper layer 14 is improved, and adhesive wear is reduced. The indentation hardness of the upper layer surface is preferably 10,000 MPa or less. When the indentation hardness of the surface of the upper layer 14 is 10000 MPa or less, bending workability is improved, and when the metal material for electronic parts of the present invention is press-molded, cracks are hardly formed in the molded part, and gas corrosion resistance Suppresses the decline.
The arithmetic average height (Ra) of the surface of the upper layer 14 is preferably 0.3 μm or less. When the arithmetic average height (Ra) of the surface of the upper layer 14 is 0.3 μm or less, the number of convex portions that are relatively easily corroded is reduced and smoothed, so that the gas corrosion resistance is improved.
The maximum height (Rz) of the surface of the upper layer 14 is preferably 3 μm or less. When the maximum height (Rz) of the surface of the upper layer 14 is 3 μm or less, the number of convex portions that are relatively easily corroded is reduced and smoothed, so that the gas corrosion resistance is improved.
The Vickers hardness of the lower layer 12 is preferably Hv300 or higher. When the Vickers hardness of the lower layer 12 is Hv300 or more, the lower layer is further cured, so that the thin film lubricating effect is further improved and adhesion wear is further reduced. On the other hand, the lower layer 12 preferably has a Vickers hardness Hv of 1000 or less. When the Vickers hardness of the lower layer 12 is Hv1000 or less, the bending workability is improved, and when the metal material for electronic parts of the present invention is press-molded, cracks are hardly formed in the molded part, and the gas corrosion resistance is lowered. Suppress.
The indentation hardness of the cross section of the lower layer 12 is preferably 1500 MPa or more. When the indentation hardness of the cross section of the lower layer 12 is 1500 MPa or more, the lower layer 12 is further cured, so that the thin film lubrication effect is further improved and adhesion wear is reduced. On the other hand, the indentation hardness of the lower layer 12 is preferably 10,000 MPa or less. When the indentation hardness of the cross section of the lower layer 12 is 10000 MPa or less, bending workability is improved, and when the metal material for electronic parts of the present invention is press-molded, cracks are hardly formed in the molded part, and gas corrosion resistance Suppresses the decline in sex.

<Applications of metal materials for electronic parts>
The use of the metal material for electronic parts of the present invention is not particularly limited. For example, a connector terminal using the metal material for electronic parts as a contact part, an FFC terminal or FPC terminal using the metal material for electronic parts as a contact part, and an electronic part Electronic parts using metal materials for external connection as electrodes for external connection. In addition, about a terminal, it does not depend on the joining method with a wiring side, such as a crimp terminal, a solder terminal, and a press fit terminal. Examples of the external connection electrode include a connection component in which a surface treatment is performed on a tab and a material in which a surface treatment is applied to a semiconductor under bump metal.
Moreover, a connector may be produced using the connector terminal formed in this way, and an FFC or FPC may be produced using an FFC terminal or an FPC terminal.
In the metal material for electronic parts of the present invention, the female terminal connection portion is provided on one side of the mounting portion to be attached to the housing, and the substrate connection portion is provided on the other side. The substrate connection portion is formed in a through hole formed on the substrate. You may use for the press-fit type terminal which press-fits and attaches to this board | substrate.
In the connector, both the male terminal and the female terminal may be the metal material for electronic parts of the present invention, or only one of the male terminal and the female terminal. In addition, low insertion property is further improved by making both the male terminal and the female terminal into the metal material for electronic parts of the present invention.

<Method for producing metal material for electronic parts>
As a method for producing a metal material for electronic parts of the present invention, wet (electrical, electroless) plating, dry (sputtering, ion plating, etc.) plating, or the like can be used.

Hereinafter, although the Example and comparative example of this invention are shown together, these are provided in order to understand this invention better, and this invention is not intended to be limited.
As examples, reference examples, and comparative examples, surface treatment was performed in the order of electrolytic degreasing, pickling, first plating, second plating, third plating, and heat treatment under the conditions shown in Table 1.

(Material)
(1) Plate material: thickness 0.30 mm, width 30 mm, component Cu-30Zn
(2) Male terminal: thickness 0.64 mm, width 2.3 mm, component Cu-30Zn
(3) Press-fit terminal: Tokiwa Shoko, press-fit terminal PCB connector, R800

(First plating condition)
(1) Semi-bright Ni plating Surface treatment method: electroplating plating solution: sulfamic acid Ni plating solution + saccharin plating temperature: 55 ° C
Current density: 0.5-4 A / dm ²
(2) Bright Ni plating Surface treatment method: electroplating Plating solution: sulfamic acid Ni plating solution + saccharin + additive Plating temperature: 55 ° C
Current density: 0.5-4 A / dm ²
(3) Cu plating Surface treatment method: electroplating Plating solution: Cu sulfate plating solution Plating temperature: 30 ° C
Current density: 0.5-4 A / dm ²
(4) Matte Ni plating Surface treatment method: electroplating Plating solution: sulfamic acid Ni plating solution Plating temperature: 55 ° C
Current density: 0.5-4 A / dm ²
(5) Ni-P plating Surface treatment method: electroplating plating solution: sulfamic acid Ni plating solution + phosphite Plating temperature: 55 ° C
Current density: 0.5-4 A / dm ²

(Second plating condition)
(1) Ag plating Surface treatment method: electroplating Plating solution: Cyanide Ag plating solution Plating temperature: 40 ° C
Current density: 0.2-4 A / dm ²
(2) Sn plating Surface treatment method: Electroplating Plating solution: Methanesulfonic acid Sn plating solution Plating temperature: 40 ° C
Current density: 0.5-4 A / dm ²

(Third plating condition)
(1) Sn plating conditions Surface treatment method: electroplating plating solution: methanesulfonic acid Sn plating solution Plating temperature: 40 ° C
Current density: 0.5-4 A / dm ²

(Heat treatment)
The heat treatment was performed by placing a sample on a hot plate and confirming that the surface of the hot plate reached a predetermined temperature.

(Post-processing)
For Examples 25 to 40, in addition to Example 1, using a phosphate ester-based liquid as a surface treatment liquid, coating by dip or anodic electrolysis (2 V, constant voltage electrolysis) was performed, and surface treatment was performed on the plating surface. went. The surface treatment conditions at this time are shown in Table 2 below. After these treatments, the sample was dried with warm air. The amount of P and N adhering to the plating surface is first determined by XPS (X-ray photoelectron analysis) using several types of samples with known adhering amounts, and P (2 s orbit) and N (1 s orbit). The detection intensity (the number of counts detected per second) was measured. Next, based on this result, a relationship between the adhesion amount and the detected intensity was derived, and the adhesion amount of P and N of the unknown sample was obtained from this relationship. An example of the XPS analysis result is shown in FIG. 2, and the relationship between the post-treatment liquid component adhesion amount and the detected XPS intensity is shown in FIG. 3 (P adhesion amount = 1.1 × 10 ⁻⁹ mol / cm ² , N adhesion amount = 7.8). × 10 ^-11 mol / cm ² is multiplied by 1).

(Determination of the structure and composition of upper and middle layers and thickness measurement)
The determination of the structure of the upper layer and the middle layer of the obtained sample and the thickness measurement were performed by line analysis by STEM (scanning electron microscope) analysis. The analyzed elements are upper layer, middle layer and lower layer compositions, C, S and O. These elements are designated elements. Further, the concentration (at%) of each element was analyzed with the total of the designated elements as 100%. The thickness corresponds to the distance obtained from line analysis (or surface analysis). JEM-2100F manufactured by JEOL Ltd. was used as the STEM apparatus. The acceleration voltage of this device is 200 kV.
Determination of the structure of the upper layer and the middle layer of the obtained sample and measurement of the thickness were performed by evaluating 10 points and averaging.

(Under layer thickness measurement)
The thickness of the lower layer was measured with a fluorescent X-ray film thickness meter (SEA 5100 manufactured by Seiko Instruments, collimator 0.1 mmΦ).
The thickness of the lower layer was averaged by evaluating 10 points.

(Evaluation)
The following evaluation was performed for each sample.
A. Adhesive wear Adhesive wear was evaluated by insertion / extraction testing with a male terminal plated using a commercially available Sn reflow plated female terminal (090 type Sumitomo TS / Yazaki 090II series female terminal non-waterproof / F090-SMTS). .
The measuring device used for the test was 1311NR made by Ikko Engineering, and the evaluation was performed with a male spin sliding distance of 5 mm. The number of samples was 5, and adhesive wear was evaluated using the insertion force. As the insertion force, a value obtained by averaging the maximum values of the respective samples was adopted. As the adhesive wear blank, the sample of Comparative Example 11 was employed.
The adhesion wear target is less than 85% compared to the maximum insertion / extraction force of Comparative Example 11. This is 90% of Comparative Example 3 compared with the maximum insertion force of Comparative Example 11, and aimed to reduce the insertion / extraction force larger than that of Comparative Example 3.

B. Whisker Whisker was evaluated by a load test (ball indenter method) of JEITA RC-5241. That is, a load test was performed on each sample, and the sample after the load test was observed at a magnification of 100 to 10,000 times with a SEM (manufactured by JEOL, model JSM-5410) to observe the occurrence of whiskers. . The load test conditions are shown below.
Diameter of ball indenter: Φ1mm ± 0.1mm
Test load: 2N ± 0.2N
Test time: 120 hours Number of samples: 10 The target characteristic is that whiskers with a length of 20 μm or more are not generated, but the maximum target is that no whisker of any length is generated. .

C. Contact resistance The contact resistance was measured by a 4-terminal method using a contact simulator CRS-113-Au type manufactured by Yamazaki Seiki Laboratories under the condition of a contact load of 50 g. The number of samples was 5, and the range from the minimum value to the maximum value of each sample was adopted. The target characteristic is a contact resistance of 10 mΩ or less.

D. Heat resistance Heat resistance was evaluated by measuring the contact resistance of a sample after an atmospheric heating (200 ° C. × 1000 h) test. The target characteristic is a contact resistance of 10 mΩ or less, and the maximum target is that the contact resistance does not change before and after the heat resistance test (is equivalent).

E. Fine sliding wear resistance Fine sliding wear resistance is measured using a precision sliding test device CRS-G2050 manufactured by Yamazaki Seiki Laboratories, sliding distance 0.5 mm, sliding speed 1 mm / s, contact load 1 N, The relationship between the number of sliding times and the contact resistance was evaluated under the condition that the number of sliding times was 500. The number of samples was 5, and the range from the minimum value to the maximum value of each sample was adopted. The target characteristic is a contact resistance of 100 mΩ or less when the number of sliding times is 100.

F. Solder wettability The solder wettability was evaluated on the sample after plating. Solder checker (SAT-5000 manufactured by Reska Co., Ltd.) was used, and a commercially available 25% rosin methanol flux was used as the flux, and the solder wetting time was measured by the meniscograph method. The solder used was Sn-3Ag-0.5Cu (250 ° C.). The number of samples was 5, and the range from the minimum value to the maximum value of each sample was adopted. The target characteristic is a zero cross time of 5 seconds (s) or less.

G. Gas Corrosion Resistance Gas corrosion resistance was evaluated in the following test environment. The evaluation of gas corrosion resistance is the appearance of a sample after a test after an environmental test. The target characteristic is that the appearance is not discolored or is slightly discolored with no practical problem.
Hydrogen sulfide gas corrosion test Hydrogen sulfide concentration: 10ppm
Temperature: 40 ° C
Humidity: 80% RH
Exposure time: 96h
Number of samples: 5

H. Mechanical durability Mechanical durability is obtained by extracting the press-fit type terminal inserted into the through hole (substrate thickness 2 mm, through hole Φ1 mm) from the through hole, and making the cross section of the press-fit type terminal into SEM (JEOL, model JSM-5410). Were observed at a magnification of 100 to 10,000 times to confirm the occurrence of powder. A powder having a diameter of less than 5 μm was evaluated as “◯”, a powder having a diameter of less than 5 to 10 μm as “Δ”, and a powder having a diameter of 10 μm or more as “X”.

I. Bending workability The bending workability was evaluated by bending at 90 ° using a W-shaped mold under the condition that the ratio of the plate thickness to the bending radius was 1. In the evaluation, the surface of the bent portion was observed with an optical microscope, and when it was judged that there was no practical problem when no crack was observed, it was evaluated as ◯, and when the crack was observed, it was evaluated as ×. In addition, it was set as △ when it cannot distinguish between ○ and ×.

J. et al. Vickers hardness The Vickers hardness of the lower layer was measured by hitting the root with a load of 980.7 mN (Hv 0.1) and a load holding time of 15 seconds from the lower layer cross section.

K. Indentation hardness The indentation hardness of the upper layer was measured by hitting a root with a load of 10 mN on the sample surface by an ultra-micro hardness test (ENTION 2100 manufactured by Elionix).
Further, the indentation hardness of the lower layer was measured by hitting the root with a load of 10 mN (Hv 0.1) and a load holding time of 15 seconds from the lower layer cross section.

L. Surface Roughness Surface roughness (arithmetic average height (Ra) and maximum height (Rz)) is measured according to JIS B 0601, a non-contact type three-dimensional measuring device (manufactured by Mitaka Kogyo Co., Ltd., model NH- 3). The cut-off was 0.25 mm, the measurement length was 1.50 mm, and measurement was performed 5 times per sample.

M.M. Relationship between upper layer thickness and minimum upper layer thickness The relationship between upper layer thickness and upper layer minimum thickness was evaluated using a HAADF (high angle scattering dark field) image by STEM (scanning electron microscope) analysis. A schematic diagram of a HAADF (High Angle Scattering Dark Field) image is shown in FIG. Evaluation was performed as follows.
(1) Evaluation was made with a reference length of 3 μm / field using a HAADF (high angle scattering dark field) image with a magnification of 50K.
(2) The minimum thickness portion of the upper layer was specified within a reference length of 3 μm / field of view. Moreover, when it was difficult to specify the minimum thickness part, the magnification was specified as high as necessary.
(3) In order to accurately determine the minimum thickness of the upper layer, observation was performed at a higher magnification than the identified portion. The “minimum thickness of the upper layer” was accurately determined using a HAADF (high angle scattering dark field) image with a magnification of 100 to 200K.
(4) The relationship between the “upper layer thickness (μm)” and the “minimum upper layer thickness (μm)” determined by the line analysis by the above-mentioned STEM (scanning electron microscope) analysis was performed by measuring five visual fields per sample. I figured it out.
FIG. 4 schematically shows the surface roughness of each layer exaggerated from the actual measurement values so that the evaluation methods (1) to (4) can be easily understood.

N. The relationship between the upper layer thickness and the maximum height difference between adjacent peaks and valleys in the interface profile between the upper layer and middle layer The upper layer thickness and the maximum difference in height between adjacent peaks and valleys in the interface profile between the upper layer and middle layer The relationship with the value was evaluated using a HAADF (high angle scattering dark field) image by STEM (scanning electron microscope) analysis. A schematic diagram of a HAADF (High Angle Scattering Dark Field) image is shown in FIG. Evaluation was performed as follows.
(1) Evaluation was made with a reference length of 3 μm / field using a HAADF (high angle scattering dark field) image with a magnification of 50K.
(2) In the reference length of 3 μm / field of view, the maximum value portion of the height difference between adjacent peaks and valleys of the interface profile between the upper layer and the middle layer was specified. Moreover, when it was difficult to specify the maximum value part of the height difference between the adjacent peaks and valleys of the interface profile between the upper layer and the middle layer, the magnification was specified as high as necessary.
(3) In order to accurately determine the maximum value portion of the height difference between the adjacent peaks and valleys of the interface profile between the upper layer and the middle layer, observation was performed at a higher magnification than the specified portion. Using a HAADF (high angle scattering dark field) image with a magnification of 100 to 200K, the “height difference between adjacent peaks and valleys in the interface profile between the upper layer and the middle layer” was accurately determined.
(4) The “upper layer thickness (μm)” and “height difference between adjacent peaks and valleys of the interface profile between the upper layer and the middle layer (μm)” determined by the line analysis by the above-mentioned STEM (scanning electron microscope) analysis The relationship was grasped by measuring 5 fields per sample.
FIG. 4 schematically shows the surface roughness of each layer exaggerated from the actual measurement values so that the evaluation methods (1) to (4) can be easily understood.
The test conditions and test results are shown in the following table. In the following table, “composition” indicates the ratio of atomic concentration (at%).

*) Regarding “phosphate ester solution treatment conditions”, Example 34 was subjected to anodic electrolysis at 2 V for 5 seconds, and other examples were subjected to immersion treatment.
A1: Lauryl acid phosphate monoester (phosphate monolauryl ester)
A2: Lauryl acid phosphate diester (phosphate dilauryl ester)
B1: Benzotriazole B2: Mercaptobenzothiazole Na salt B3: Tolyltriazole

Examples 1-41 were electronic component metal materials excellent in all of low whisker properties, low adhesion wear properties, and high durability.
In Reference Example 1, Ag: Sn in the upper layer is 3: 7, and the ratio of Sn in the upper layer is larger than that in Example 1. Therefore, although target characteristics were obtained, whiskers with a length of 20 μm or more were generated. In some cases, whiskers having a length of less than 20 μm were generated.
In Reference Example 2, Sn: Ni in the middle layer is 3: 7, and since the ratio of Ni in the middle layer is larger than that in Example 1, the target characteristics are obtained, but bending is performed in comparison with Example 1. The processability was slightly bad.
In Reference Example 3, the thickness of the upper layer was 0.90 μm, and the target characteristics were obtained, but the thickness of the upper layer was thicker than that of Example 1, and the mechanical durability was slightly higher than that of Example 1. It was bad.
In Reference Example 4, the ratio of the thickness of the upper layer to the lower layer is upper layer: lower layer = 1: 3, and the ratio of the lower layer is large, so the target characteristics were obtained, but heat resistance, anti-sliding wear resistance, solder The wettability and gas corrosion resistance were slightly worse compared to the examples.
In Reference Example 5, the ultrafine hardness of the upper layer, the ultrafine hardness of the lower layer, and the Vickers hardness are harder than those of Example 1, so that the target characteristics were obtained, but the bending workability was poor. It was.
In Reference Example 6, the minimum thickness of the outermost layer was less than 50% of the thickness of the outermost layer, and the target characteristics were obtained, but the heat resistance, solder wettability, and gas corrosion resistance were worse than the examples. .
In Reference Example 7, the maximum value of the height difference between adjacent peaks and valleys in the interface profile between the outermost layer and the upper layer exceeded 50% of the thickness of the outermost layer, so that the target characteristics were obtained, but the heat resistance The solder wettability and gas corrosion resistance were worse than those of the examples.
In Reference Example 8, the total atomic concentration of B constituent elements (at%) ≧ the total atomic concentration of C constituent elements (at%) and the atomic concentration of O (at%) ≧ 10 at% on the surface of the upper layer However, although the target characteristics were obtained, the heat resistance and solder wettability were worse than those of the examples.
In Reference Example 9, the thickness of the upper layer was 0.03 μm, which was thinner than that of the example. Therefore, although target characteristics were obtained, the heat resistance, solder wettability, and gas corrosion resistance were worse than those of the example.
In Comparative Example 1, since the thickness of the upper layer was thinner than the target, the heat resistance, the fine sliding wear resistance, the solder wettability, and the gas corrosion resistance were poor.
In Comparative Example 2, since the thickness of the upper layer was thicker than the target, there was much adhesion wear, so the insertion force was high and the mechanical wearability was poor.
In Comparative Example 3, since the upper layer was formed of βSn alone, whiskers having a length of 20 μm or more were generated, and since there was much adhesion wear, the insertion force was high, and the heat resistance and fine sliding wear resistance were poor.
In Comparative Example 4, since the thickness of the middle layer was thinner than the target, there was much adhesive wear, so the insertion force was high.
In Comparative Example 5, since the thickness of the middle layer was thicker than the target, mechanical wear and bending workability were poor.
In Comparative Example 6, since the thickness of the lower layer was thinner than the target, there was much adhesion wear, so the insertion force was high , and the heat resistance and solder wettability were poor.
In Comparative Example 7, since the thickness of the lower layer was thicker than the target, bending workability was poor.
In Comparative Examples 8 to 9 , since the ratio of Ag in the upper layer was high, the gas corrosion resistance was poor.
Comparative Example 11 is a blank material of the present invention. Whisker having a length of 20 μm or more was generated, and heat resistance and fine sliding wear resistance were poor.
FIG. 5 shows a line analysis result of a STEM (scanning electron microscope) according to the embodiment of the present invention. From FIG. 5, it can be seen that the AgSn alloy is present at a thickness of 0.3 μm and the SnNi alloy is present at a thickness of 0.07 μm from the outermost surface. Further, the composition (at%) of the AgSn alloy is Ag: Sn = 8: 2, and from the AgSn phase diagram of FIG. 6, there is no βSn in the AgSn alloy, and the ζ phase (Sn 11.8-22.Sn) of the SnAg alloy. 9%) and ε phase (Ag ₃ Sn). Further, the composition (at%) of the SnNi alloy is Sn: Ni = 7: 3, and it can be seen from the SnNi phase diagram of FIG. 7 that Ni ₃ Sn ₄ and βSn of the SnNi alloy exist.

DESCRIPTION OF SYMBOLS 10 Metal material for electronic components 11 Base material 12 Lower layer 13 Middle layer 14 Upper layer

Claims (49)

A substrate;
A lower layer composed of one or more selected from the group consisting of Ni, Cr, Mn, Fe, Co and Cu, which is a group consisting of A constituent elements, formed on the substrate;
It is composed of one or more selected from the A constituent element group formed on the lower layer and one or two selected from the B constituent element group which is a group consisting of Sn and In. The middle layer,
One or two selected from the B constituent element group formed on the middle layer and a C constituent element group that is a group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir An upper layer composed of an alloy of one kind or two or more kinds,
With
The thickness of the lower layer is 0.05 μm or more and less than 5.00 μm,
The middle layer has a thickness of 0.01 μm or more and less than 0.40 μm,
Metal material for electronic parts the upper layer of thickness Ru 1.00μm less der than 0.02 [mu] m.
  The metal material for an electronic component according to claim 1, wherein the minimum thickness (μm) of the upper layer is 50% or more of the thickness (μm) of the upper layer.   3. The electronic component according to claim 1, wherein a maximum value (μm) of a difference in height between adjacent peaks and valleys in an interface profile between the upper layer and the middle layer is 50% or less of a thickness (μm) of the upper layer. Metal materials.   On the surface of the upper layer, a region where the total atomic concentration of B constituent elements (at%) ≧ the total atomic concentration of C constituent elements (at%) and the atomic concentration of O (at%) ≧ 10 at% is 0.02 μm. The metal material for electronic components according to any one of claims 1 to 3, which is present in the following.   The metal material for electronic components according to any one of claims 1 to 4, wherein the upper layer contains 10 to 50 at% of the metal of the B constituent element group.   The metal material for electronic components according to any one of claims 1 to 5, wherein a ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% of Sn is present in the upper layer. The metal material for electronic components according to any one of claims 1 to 5, wherein an ε (epsilon) phase that is Ag ₃ Sn exists in the upper layer. The ζ (zeta) phase which is a SnAg alloy containing 11.8 to 22.9 at% Sn and an ε (epsilon) phase which is Ag ₃ Sn are present in the upper layer. Metal materials for electronic parts. The metal material for electronic components according to any one of claims 1 to 5, wherein only the ε (epsilon) phase that is Ag ₃ Sn exists in the upper layer. The metal material for an electronic component according to any one of claims 1 to 5, wherein an ε (epsilon) phase that is Ag ₃ Sn and βSn that is a Sn single phase are present in the upper layer. The ζ (zeta) phase that is a SnAg alloy containing 11.8 to 22.9 at% Sn, an ε (epsilon) phase that is Ag ₃ Sn, and βSn that is a Sn single phase are present in the upper layer. Metal material for electronic components in any one of 1-5.   The metal material for an electronic component according to any one of claims 1 to 11, wherein the intermediate layer contains 35 at% or more of the metal of the B constituent element group. The metal material for electronic components according to any one of claims 1 to 12, wherein Ni ₃ Sn ₄ and Ni ₃ Sn ₂ are present in the intermediate layer. The metal material for electronic components according to claim 1, wherein Ni ₃ Sn ₄ and βSn that is a Sn single phase are present in the intermediate layer.   The metal material for an electronic component according to any one of claims 1 to 14, wherein a thickness ratio between the upper layer and the middle layer is upper layer: middle layer = 9: 1 to 3: 7.   The metal for electronic parts according to any one of claims 1 to 15, wherein C, S, and O are each contained in an amount of 2 at% or less from the upper layer to the middle layer excluding a range of 0.03 µm from the outermost surface of the upper layer. material.   The indentation hardness of the surface of the upper layer, which is a hardness obtained by measuring the surface of the upper layer with a load of 10 mN by an ultra micro hardness test, is 1000 MPa or more. The metal material for electronic components in any one.   The indentation hardness of the surface of the upper layer, which is the hardness obtained by measuring the surface of the upper layer with a load of 10 mN by an ultra micro hardness test, is 10,000 MPa or less. The metal material for electronic components in any one.   The metal material for an electronic component according to any one of claims 1 to 18, wherein an arithmetic average height (Ra) of a surface of the upper layer is 0.3 µm or less.   The metal material for electronic parts according to any one of claims 1 to 19, wherein a maximum height (Rz) of the surface of the upper layer is 3 µm or less. The upper layer, the middle layer and the lower layer are
One or more selected from the A constituent element group is formed on the substrate, and then one or two selected from the C constituent element group is formed, and then the B The film is formed by depositing one kind or two or more kinds selected from a constituent element group, and each element of the A constituent element group, the B constituent element group, and the C constituent element group is diffused. The metal material for electronic components in any one of 1-20.   The metal material for electronic parts according to claim 21, wherein the diffusion is performed by heat treatment.   The heat treatment is performed at a temperature equal to or higher than the melting point of the metal of the B constituent element group, and one or two alloys selected from the B constituent element group and one or more alloys selected from the A constituent element group The layer according to claim 21 or 22, wherein one or two or more kinds of alloy layers selected from the B constituent element group and one or two kinds selected from the C constituent element group are formed. Metal materials for electronic parts.   The metal of the A constituent element group is 50 mass% or more in total of Ni, Cr, Mn, Fe, Co, and Cu, and further, one or more selected from the group consisting of B, P, Sn, and Zn The metal material for electronic components according to any one of claims 1 to 23.   The metal of the B constituent element group is 50 mass% or more in total of Sn and In, and the remaining alloy components are Ag, As, Au, Bi, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb The metal material for electronic parts according to any one of claims 1 to 24, comprising one or more metals selected from the group consisting of Sb, W and Zn.   The metal of the C constituent element group is 50 mass% or more in total of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir, and the remaining alloy components are Bi, Cd, Co, Cu, Fe, In, Mn The metal for electronic components according to any one of claims 1 to 25, comprising one or more metals selected from the group consisting of Mo, Ni, Pb, Sb, Se, Sn, W, Tl, and Zn. material.   27. The metal material for an electronic component according to claim 1, wherein a Vickers hardness of a cross section of the lower layer is Hv300 or more.   28. The indentation hardness of the lower layer cross section, which is the hardness obtained by measuring the cross section of the lower layer with a load of 10 mN by an ultra micro hardness test, is 1500 MPa or more. The metal material for electronic components in any one.   The metal material for an electronic component according to any one of claims 1 to 28, wherein a Vickers hardness of a cross section of the lower layer is Hv1000 or less.   30. The indentation hardness of the lower layer cross section, which is a hardness obtained by measuring an indentation with a load of 10 mN in the lower layer cross section by an ultra-micro hardness test, is 10,000 MPa or less. The metal material for electronic components in any one. The metal material for electronic components according to any one of claims 1 to 30, wherein the intermediate layer is composed of Ni ₃ Sn and Ni ₃ Sn ₂ . The metal material for electronic components according to any one of claims 1 to 30, wherein the intermediate layer is made of Ni ₃ Sn ₂ . The metal material for electronic components according to any one of claims 1 to 30, wherein the intermediate layer is made of Ni ₃ Sn ₄ .   The metal material for electronic components according to any one of claims 1 to 33, further comprising a layer formed of an alloy of a metal of the A constituent element group and a metal of the C constituent element group between the lower layer and the middle layer. The metal for electronic parts according to any one of claims 1 to 34, wherein P is attached to the surface of the upper layer, and the amount of the P attached is 1 x 10 ^-11 to 4 x 10 ^-8 mol / cm ^2. material. 36. The metal material for an electronic component according to claim 35, wherein N further adheres to the surface of the upper layer, and the adhesion amount of N is 2 × 10 ⁻¹² to 8 × 10 ⁻⁹ mol / cm ² .   When the upper layer is analyzed by XPS, the detected photoelectron intensity caused by 2S orbital electrons of P is I (P2s), and the photoelectron detected intensity caused by 1S orbital electrons of N is I (N1s). 37. The metal material for electronic parts according to claim 35 or 36, wherein 1 ≦ I (P2s) / I (N1s) ≦ 1 is satisfied.   When the upper layer is analyzed by XPS, the detected photoelectron intensity caused by 2S orbital electrons of P is I (P2s), and the photoelectron detected intensity caused by 1S orbital electrons of N is I (N1s). 37. The metal material for electronic parts according to claim 35 or 36, wherein I (P2s) / I (N1s) ≦ 50 is satisfied. A substrate;
A lower layer composed of one or more selected from the group consisting of Ni, Cr, Mn, Fe, Co and Cu, which is a group consisting of A constituent elements, formed on the substrate;
It is composed of one or more selected from the A constituent element group formed on the lower layer and one or two selected from the B constituent element group which is a group consisting of Sn and In. The middle layer,
One or two selected from the B constituent element group formed on the middle layer and a C constituent element group that is a group consisting of Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir An upper layer composed of an alloy of one kind or two or more kinds,
On the surface of a metal material provided with at least one of the phosphoric acid esters represented by the following general formulas [1] and [2], and a cyclic organic compound group represented by the following general formulas [3] and [4] The method for producing a metal material for electronic parts according to any one of claims 35 to 38, wherein the surface treatment is performed with a phosphate ester-based liquid containing at least one selected from the group consisting of:
(In the formulas [1] and [2], R ₁ and R ₂ each represent a substituted alkyl, and M represents hydrogen or an alkali metal.)
(In the formulas [3] and [4], R ₁ represents hydrogen, alkyl, or substituted alkyl, R ₂ represents an alkali metal, hydrogen, alkyl, or substituted alkyl, R ₃ represents an alkali metal or hydrogen, R ₄ represents —SH, an amino group substituted with an alkyl group or an aryl group, or alkyl-substituted imidazolylalkyl, and R ₅ and R ₆ represent —NH ₂ , —SH or —SM (M represents an alkali metal). Represents.)   40. The method for producing a metal material for an electronic component according to claim 39, wherein the surface treatment with the phosphoric ester liquid is performed by applying a phosphoric ester liquid to the surface of the upper layer.   40. The surface treatment with the phosphate ester-based liquid is performed by immersing the metal material after the upper layer formation in a phosphate ester-based liquid and performing electrolysis using the metal material after the upper layer formation as an anode. Manufacturing method of metal materials for electronic parts.   The connector terminal which used the metal material for electronic components in any one of Claims 1-38 for the contact part.   The connector using the connector terminal of Claim 42.   The FFC terminal which used the metal material for electronic components in any one of Claims 1-38 for the contact part.   The FPC terminal which used the metal material for electronic components in any one of Claims 1-38 for the contact part.   45. An FFC using the FFC terminal according to claim 44.   An FPC using the FPC terminal according to claim 45.   The electronic component which used the metal material for electronic components in any one of Claims 1-38 for the electrode for external connection.   A metal terminal connection portion is provided on one side of a mounting portion for attaching the metal material for electronic components according to any one of claims 1 to 38 to a housing, and a substrate connection portion is provided on the other side. An electronic component used for a press-fit terminal that is press-fitted into a through-hole formed on the board and attached to the substrate.