Metal material, contact terminal, and connector

Abstract

A metal material comprising a base material and a platinum group-containing layer. The platinum group-containing layer covers the base material in a state in which a precious metal layer with a thickness of more than 1.0 μm is not present between the base material and the platinum group-containing layer, or in a state in which a precious metal layer with a thickness of 1.0 μm or less is positioned between the base material and the platinum group-containing layer.

Description

Metal Material, Contact Terminal, and Connector

[0001] The present invention relates to a metal material, a contact terminal, and a connector.

[0002] In recent years, various metal materials for contact terminals of connectors have been developed.

[0003] Patent Document 1 describes an electrical contact. The electrical contact includes a conductive base metal, a nickel layer located on the base metal, and a gold-nickel alloy layer located on the nickel layer.

[0004] Patent Document 2 describes a terminal material for a connector. The terminal material for a connector includes a base material, a nickel plating layer made of nickel or a nickel alloy formed on the base material, and a silver-gold alloy plating layer formed on the nickel plating layer.

[0005] Patent Document 3 describes a connection terminal. The connection terminal includes a plating layer formed on copper or a copper alloy. The plating layer contains Pd, Ag, Pd, Au, and Pt. Pd, Ag, Pd, Au, and Pt are laminated in this order from copper or a copper alloy.

[0006] Japanese Patent Application Laid-Open No. 2002-231357, Japanese Patent Application Laid-Open No. 2020-117770, Chinese Patent Application Publication No. 112376094

[0007] For metal materials such as contact terminals that are electrically connected to the connection target of a connector, it may be necessary to improve corrosion resistance.

[0008] An example of the object of the present invention is to improve the corrosion resistance of the metal material. Other objects of the present invention will become apparent from the description herein.

[0009] One aspect of the present invention includes a base material and a platinum group-containing layer. The platinum group-containing layer covers the base material in a state where a noble metal layer thicker than 1.0 μm does not exist between the base material and the platinum group-containing layer, or in a state where a noble metal layer of 1.0 μm or less is located between the base material and the platinum group-containing layer, and is a metal material.

[0010] One aspect of the present invention is a contact terminal that is electrically connected to an object to be connected, and the contact terminal comprises the above-mentioned metal material.

[0011] One aspect of the present invention is a connector equipped with the above-mentioned contact terminals.

[0012] One aspect of the present invention is a metallic material comprising: a base material; a platinum group metal-containing layer; and a layer mainly composed of copper and a copper alloy, wherein the platinum group metal-containing layer covers the base material with the layer mainly composed of copper and the copper alloy positioned between the base material and the platinum group metal-containing layer.

[0013] One aspect of the present invention is a contact terminal that is electrically connected to an object to be connected, and the contact terminal comprises the above-mentioned metal material.

[0014] One aspect of the present invention is a connector equipped with the above-mentioned contact terminals.

[0015] One aspect of the present invention is a metallic material comprising a base material, a platinum group metal-containing layer, and a layer free of nickel components, wherein the platinum group metal-containing layer covers the base material with the layer free of nickel components positioned between the base material and the platinum group metal-containing layer.

[0016] One aspect of the present invention is a contact terminal that is electrically connected to an object to be connected, and the contact terminal comprises the above-mentioned metal material.

[0017] One aspect of the present invention is a connector equipped with the above-mentioned contact terminals.

[0018] According to the above embodiment of the present invention, the corrosion resistance of metal materials can be improved.

[0019] This is a top view of the connector according to the embodiment. This is a side view of the connector and substrate according to the embodiment. This is a side view of the contact terminal according to the embodiment. This is a diagram showing the metal material that at least partially constitutes the contact terminal according to the embodiment. This is a diagram showing the metal material according to Reference Embodiment 1. This is a diagram showing the metal material according to Reference Embodiment 2. This is a diagram showing the metal material according to Modification Example 1. This is a diagram showing the metal material according to Modification Example 2.

[0020] Embodiments and modified examples of the present invention will be described below with reference to the drawings. In all drawings, similar components are denoted by the same reference numerals, and their descriptions are omitted where appropriate.

[0021] Figure 1 is a top view of the connector 10 according to the embodiment. Figure 2 is a side view of the connector 10 and the substrate 20 according to the embodiment. Figure 3 is a side view of the contact terminal 100 according to the embodiment.

[0022] To explain the directions, we define the X, Y, and Z directions. The Z direction is parallel to the vertical direction. The X direction is one of the horizontal directions perpendicular to the Z direction. The Y direction is one of the horizontal directions perpendicular to both the Z and X directions. In this embodiment, the direction indicated by the Z-axis arrow is defined as the upward direction.

[0023] The connector 10 according to this embodiment includes a plurality of contact terminals 100, a housing 200, and a plurality of guide pins 300.

[0024] In this embodiment, as shown in Figure 1, eight contact terminals 100 are arranged in two rows and four columns in the Y and X directions, respectively, when viewed from the Z direction. The number and arrangement of the contact terminals 100 are not limited to the example shown in Figure 1.

[0025] As shown in Figure 3, each contact terminal 100 has a head portion 110, a tapered portion 120, a column portion 130, and a tip portion 140. As shown in Figure 1, the head portion 110 is substantially circular when viewed from the Z direction. As shown in Figure 3, the tapered portion 120 extends downward from the lower end of the head portion 110 on the -Z side. The horizontal diameter of the tapered portion 120 decreases as it extends downward from the -Z side. As shown in Figure 3, the column portion 130 extends downward from the lower end of the tapered portion 120 on the -Z side. As viewed from the Z direction, the column portion 130 is substantially circular. As shown in Figure 3, the tip portion 140 is provided at the lower end of the column portion 130 on the -Z side. The horizontal diameter of the tip portion 140 is larger than the horizontal diameter of the column portion 130. The shape of the contact terminal 100 is not limited to the example shown in Figure 3.

[0026] The housing 200 is electrically insulating. As shown in Figure 1, when viewed from the Z direction, the housing 200 has a roughly rectangular shape with rounded corners, having a pair of long sides substantially parallel to the X direction and a pair of short sides substantially parallel to the Y direction. The shape of the housing 200 is not limited to the example shown in Figure 1. As shown in Figures 1 and 2, the housing 200 holds a plurality of contact terminals 100, with each contact terminal 100 penetrating the housing 200 in the Z direction. As shown in Figures 1 and 2, each contact terminal 100 penetrates the housing 200 in the Z direction. With each contact terminal 100 penetrating the housing 200 in the Z direction, the upper surface of the head 110 on the +Z side is exposed from the upper surface of the housing 200 on the +Z side. With each contact terminal 100 penetrating the housing 200 in the Z direction, the lower surface of the tip 140 on the -Z side is exposed from the lower surface of the housing 200 on the -Z side.

[0027] As shown in Figure 2, the multiple guide pins 300 protrude downward from the lower surface on the -Z side of the housing 200 toward the -Z side. In Figure 2, the substrate 20 is shown transparently so that the multiple guide pins 300 are visible. The dashed line in Figure 2 that indicates the substrate 20 shows the outline of the substrate 20. In the embodiment, as shown in Figure 1, when viewed from the Z direction, the connector 10 includes a guide pin 300 positioned approximately in the center of the -X side of the housing 200 in the Y direction, and other guide pins 300 positioned at the corners of the +X side and +Y side of the housing 200. The number and arrangement of the multiple guide pins 300 are not limited to the example shown in Figure 1. In the example shown in Figure 2, the Z-direction dimension of the multiple guide pins 300 is greater than the Z-direction thickness of the substrate 20. Therefore, in the example shown in Figure 2, the multiple guide pins 300 penetrate the substrate 20 in the Z direction, allowing the connector 10 and the substrate 20 to guide each other. The relationship between the Z-direction dimensions of the multiple guide pins 300 and the Z-direction thickness of the substrate 20 is not limited to the example shown in Figure 2. The Z-direction dimensions of the multiple guide pins 300 may be less than or equal to the Z-direction thickness of the substrate 20. Even if the Z-direction dimensions of the multiple guide pins 300 are less than or equal to the Z-direction thickness of the substrate 20, the multiple guide pins 300 can be inserted into the substrate 20 in the Z-direction to guide the connector 10 and the substrate 20 toward each other.

[0028] The connector 10 according to this embodiment is used to electrically connect an external connector (not shown) and a substrate 20 to each other. When the external connector and the substrate 20 are electrically connected to each other using the connector 10, the upper surface on the +Z side of each contact terminal 100 and the external terminal (not shown) provided on the external connector are electrically connected to each other. When the external connector and the substrate 20 are electrically connected to each other using the connector 10, the lower surface on the -Z side of the tip portion 140 of each contact terminal 100 and the conductor pattern formed on the upper surface on the +Z side of the substrate 20 are electrically connected to each other. Therefore, the external terminals of the external connector and the conductor pattern of the substrate 20 are targets for electrical connection to each contact terminal 100.

[0029] The connector 10 according to this embodiment may be used in wearable devices such as wireless earphones and hearing aids. When the connector 10 is used in a wearable device, the upper surface on the +Z side of the head 110 and the surrounding area may come into contact with the skin. As will be described in detail later, in this embodiment, the upper surface on the +Z side of the head 110 and the surrounding area can be formed from a nickel-free metal material. Therefore, the connector 10 according to this embodiment is easily usable in wearable devices and other components that come into contact with the skin.

[0030] Figure 4 shows a metal material 102 that at least partially constitutes the contact terminal 100 according to the embodiment.

[0031] In the example shown in Figure 4, the metal material 102 is described as constituting the upper surface on the +Z side of the head 110 of the contact terminal 100 according to the embodiment. However, the metal material 102 may constitute a different portion from the upper surface on the +Z side of the head 110 of the contact terminal 100. For example, the metal material 102 may constitute a side surface of the head 110 perpendicular to the Z direction.

[0032] As shown in Figure 4, the metal material 102 according to this embodiment has a base material 102a, a copper-containing layer 102b1, and a platinum group metal-containing layer 102c. Hereinafter, unless otherwise specified, the thickness of the copper-containing layer 102b1 refers to the thickness of the copper-containing layer 102b1 in the direction normal to the upper surface on the +Z side of the base material 102a. In the example shown in Figure 4, the direction normal to the upper surface on the +Z side of the base material 102a is substantially parallel to the Z direction.Hereafter, unless otherwise specified, the thickness of the platinum group metal-containing layer 102c refers to the thickness of the platinum group metal-containing layer 102c in the direction normal to the upper surface on the +Z side of the base material 102a.

[0033] The base material 102a contains metal (A) as its main component. Metal (A) contains copper as its main component. When metal (A) contains copper as its main component, the base material 102a contains at least 50 parts by mass of copper, for example, 50% of the total mass, per 100 parts by mass of the base material 102a. Brass is an example of metal (A). Metal (A) may also contain iron as its main component. When metal (A) contains iron as its main component, the base material 102a contains at least 50 parts by mass of iron, for example, 50% of the total mass, per 100 parts by mass of the base material 102a. The base material 102a is formed into a predetermined shape, for example, by cutting.

[0034] The copper-containing layer 102b1 covers the upper surface of the base material 102a on the +Z side. The copper-containing layer 102b1 mainly contains copper (B1). The copper-containing layer 102b1 contains, for example, 90% of the total mass, or 90 parts by mass or more, of copper (B1) per 100 parts by mass of the total mass of the copper-containing layer 102b1. The copper-containing layer 102b1 is formed, for example, by plating.

[0035] When the copper-containing layer 102b1 is located between the base material 102a and the platinum group metal-containing layer 102c in the Z direction, the substrate of the platinum group metal-containing layer 102c can be flattened compared to the case where the platinum group metal-containing layer 102c is formed directly on the upper surface of the base material 102a on the +Z side, without the copper-containing layer 102b1 being provided between the base material 102a and the platinum group metal-containing layer 102c in the Z direction. The greater the thickness of the copper-containing layer 102b1, the easier it is to ensure the flatness of the copper-containing layer 102b1. From the viewpoint of ensuring the flatness of the copper-containing layer 102b1, the thickness of the copper-containing layer 102b1 is, for example, 0.1 μm or more. The upper limit of the thickness of the copper-containing layer 102b1 is not particularly limited, but is, for example, 10 μm. Therefore, the thickness of the copper-containing layer 102b1 can be, for example, 0.1 μm or more and 10 μm or less. The thickness of the copper-containing layer 102b1 is measured, for example, by observing the copper-containing layer 102b1 using a scanning electron microscope (SEM).

[0036] In the example shown in Figure 4, the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a are in direct contact with each other. However, a layer different from the base material 102a and the copper-containing layer 102b1 may exist between the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a. As will be described in detail later, it is preferable that the layer located between the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a is not a noble metal layer thicker than 1.0 μm, but it may be any layer.

[0037] The platinum group metal-containing layer 102c covers the upper surface of the copper-containing layer 102b1 on the +Z side. The platinum group metal-containing layer 102c can improve the corrosion resistance of the metal material 102. In the example shown in Figure 4, the platinum group metal-containing layer 102c is located on the outermost surface of the metal material 102. The platinum group metal-containing layer 102c mainly contains platinum group metals (C). The platinum group metal-containing layer 102c contains, for example, 90% of the total mass, or 90 parts by mass or more, of platinum group metals (C) per 100 parts by mass of the total mass of the platinum group metal-containing layer 102c. Examples of platinum group metals (C) include platinum, ruthenium, rhodium, palladium, osmium, or iridium. These platinum group metals exemplified as platinum group metals (C) may be used individually or in combination as platinum group metals (C). Platinum group metals (C) may also be platinum group alloys. From the viewpoint of corrosion resistance and conductivity, the platinum group (C) is preferably platinum. The platinum group containing layer 102c may contain a different metal or alloy from the platinum group, such as PdCo. The platinum group containing layer 102c is formed, for example, by plating.

[0038] The thickness of the platinum group metal-containing layer 102c is, for example, 0.7 μm or more, preferably 1.0 μm or more, more preferably 1.5 μm or more, and even more preferably 2.0 μm or more. The thickness of the platinum group metal-containing layer 102c is measured, for example, by observation of the platinum group metal-containing layer 102c using a scanning electron microscope (SEM) or by measurement of the thickness of the platinum group metal-containing layer 102c using an X-ray fluorescence thickness gauge. The thicker the platinum group metal-containing layer 102c, the more the corrosion resistance of the metal material 102 can be improved by the corrosion resistance of the platinum group metal-containing layer 102c itself. Furthermore, the thicker the platinum group metal-containing layer 102c, the more the diffusion and deposition of copper (B1) onto the upper surface on the +Z side of the platinum group metal-containing layer 102c can be suppressed. Therefore, the decrease in corrosion resistance due to the deposition of copper (B1) on the upper surface on the +Z side of the platinum group metal-containing layer 102c can be suppressed. The upper limit of the thickness of the platinum group metal-containing layer 102c is not particularly limited, but is, for example, 20 μm. The thickness of the platinum group metal-containing layer 102c can be adjusted, for example, by the plating time for forming the platinum group metal-containing layer 102c.

[0039] The crystallite size of the platinum group metal-containing layer 102c is, for example, 20.0 nm or larger. The crystallite size of the platinum group metal-containing layer 102c is calculated, for example, from the X-ray diffraction spectrum of the platinum group metal-containing layer 102c using the WPPD (Whole Powder Pattern Deconvolution) method. The larger the crystallite size of the platinum group metal-containing layer 102c, the better the corrosion resistance of the metal material 102 can be. For example, if the crystallite size of the platinum group metal-containing layer 102c is 20.0 nm or larger, the corrosion resistance of the metal material 102 can be improved. The crystallite size of the platinum group metal-containing layer 102c can be adjusted by conditions for forming the platinum group metal-containing layer 102c, such as the current density of the plating, the plating time, and the type of plating solution.

[0040] The residual stress of the platinum group metal-containing layer 102c is, for example, between 300 MPa and 1200 MPa. The residual stress of the platinum group metal-containing layer 102c is measured, for example, by a two-dimensional stress analysis method for the platinum group metal-containing layer 102c. The residual stress of the platinum group metal-containing layer 102c can be adjusted by conditions for forming the platinum group metal-containing layer 102c, such as the current density of the plating, the plating time, and the type of plating solution.

[0041] The ratio of (200) faces to the sum of (200), (220), and (222) faces in the platinum group metal-containing layer 102c is, for example, 2.5% to 30.0%. The ratio of (220) faces to the sum of (200), (220), and (222) faces in the platinum group metal-containing layer 102c is, for example, 40.0% to 95.0%. The ratio of (222) faces to the sum of (200), (220), and (222) faces in the platinum group metal-containing layer 102c is, for example, 2.5% to 30.0%.

[0042] Hereafter, unless otherwise specified, the ratio of (200) faces of the platinum group metal-containing layer 102c refers to the ratio of (200) faces to the sum of (200), (220), and (222) faces of the platinum group metal-containing layer 102c. Hereafter, unless otherwise specified, the ratio of (220) faces of the platinum group metal-containing layer 102c refers to the ratio of (220) faces to the sum of (200), (220), and (222) faces of the platinum group metal-containing layer 102c. Hereafter, unless otherwise specified, the ratio of (222) faces of the platinum group metal-containing layer 102c refers to the ratio of (222) faces to the sum of (200), (220), and (222) faces of the platinum group metal-containing layer 102c.

[0043] The ratios of the (200) plane, (220) plane, and (222) plane of the platinum group element-containing layer 102c are calculated, for example, as the ratios of the integrated value of the peak of the (200) plane, the integrated value of the peak of the (220) plane, and the integrated value of the peak of the (222) plane to the total of the integrated values of the peaks of the (200) plane, (220) plane, and (222) plane in the X-ray diffraction spectrum of the platinum group element-containing layer 102c. The ratios of the (200) plane, (220) plane, and (222) plane of the platinum group element-containing layer 102c can be adjusted by conditions for forming the platinum group element-containing layer 102c, such as the current density of plating, the plating time, the type of plating solution, etc.

[0044] In the example shown in FIG. 4, the lower surface on the -Z side of the platinum group element-containing layer 102c and the upper surface on the +Z side of the copper-containing layer 102b1 are in direct contact with each other. However, a layer different from the copper-containing layer 102b1 and the platinum group element-containing layer 102c may exist between the lower surface on the -Z side of the platinum group element-containing layer 102c and the upper surface on the +Z side of the copper-containing layer 102b1. Although details will be described later, the layer located between the lower surface on the -Z side of the platinum group element-containing layer 102c and the upper surface on the +Z side of the copper-containing layer 102b1 is preferably not a noble metal layer thicker than 1.0 μm, but any layer may be used.

[0045] FIG. 5 is a diagram showing the metal material 102R1 according to Reference Embodiment 1. The metal material 102R1 according to Reference Embodiment 1 is the same as the metal material 102 according to the embodiment, except for the following points.

[0046] The metal material 102R1 according to Reference Embodiment 1 has a base material 102a, a nickel layer 102d1, and a gold layer 102e1. The nickel layer 102d1 covers the upper surface on the +Z side of the base material 102a. The nickel layer 102d1 contains nickel as a main component. The gold layer 102e1 covers the upper surface on the +Z side of the nickel layer 102d1. The gold layer 102e1 contains gold as a main component.

[0047] The metal material 102 according to the embodiment and the metal material 102R1 according to Reference Embodiment 1 are compared.

[0048] The metal material 102R1 according to Reference Embodiment 1 does not have a platinum group metal-containing layer corresponding to the platinum group metal-containing layer 102c in the embodiment. In contrast to the metal material 102R1 according to Reference Embodiment 1, the metal material 102 according to the embodiment has a platinum group metal-containing layer 102c. By having the platinum group metal-containing layer located on the outermost surface of the metal material, electrolytic corrosion of the metal material can be suppressed. Therefore, the metal material 102 according to the embodiment is more susceptible to electrolytic corrosion than the metal material 102R1 according to Reference Embodiment.

[0049] The metal material 102R1 according to Reference Embodiment 1 contains nickel components derived from the nickel layer 102d1. In contrast to the metal material 102R1 according to Reference Embodiment 1, the metal material 102 according to the embodiment substantially does not contain nickel components. Specifically, in the embodiment, there are no nickel components between the platinum group metal-containing layer 102c and the base material 102a and the platinum group metal-containing layer 102c. The absence of nickel components between the platinum group metal-containing layer 102c and the base material 102a and the platinum group metal-containing layer 102c means that the nickel component in the region between the platinum group metal-containing layer 102c and the lower surface on the -Z side of the platinum group metal-containing layer 102c and the upper surface on the +Z side of the copper-containing layer 102b1, and in the region between the copper-containing layer 102b1 and the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a is, for example, 10,000 ppm or less. It is preferable that the base material 102a does not contain nickel. The absence of nickel in the base material 102a means that the nickel content in the base material 102a is, for example, 10,000 ppm or less. However, the base material 102a may contain nickel, and may be made of, for example, SUS316L. The metal material 102 according to this embodiment can be nickel-free compared to the metal material 102R1 according to Reference Embodiment 1. Therefore, the metal material 102 according to this embodiment can be more easily used for components that come into contact with the skin, such as wearable devices, compared to the metal material 102R1 according to Reference Embodiment 1.

[0050] Figure 6 shows the metal material 102R2 according to Reference Embodiment 2. The metal material 102R2 according to Reference Embodiment 2 is the same as the metal material 102 according to the embodiment, except for the following points.

[0051] The metal material 102R2 according to Reference Form 2 has a base material 102a, a palladium layer 102f2, a silver layer 102g2, a gold layer 102e2, and a platinum layer 102c2. The palladium layer 102f2 covers the upper surface of the base material 102a on the +Z side. The palladium layer 102f2 mainly contains palladium. The silver layer 102g2 covers the upper surface of the palladium layer 102f2 on the +Z side. The silver layer 102g2 mainly contains silver. The gold layer 102e2 covers the upper surface of the silver layer 102g2 on the +Z side. The gold layer 102e2 mainly contains gold. The platinum layer 102c2 covers the upper surface of the gold layer 102e2 on the +Z side. The platinum layer 102c2 mainly contains platinum. The palladium layer 102f2, the silver layer 102g2, and the gold layer 102e2 are precious metal layers. The combined thickness of the palladium layer 102f2, the silver layer 102g2, and the gold layer 102e2 is greater than 1.0 μm.

[0052] The metal material 102 according to the embodiment and the metal material 102R2 according to reference embodiment 2 are compared.

[0053] In the metal material 102R2 according to Reference Embodiment 2, a noble metal layer thicker than 1.0 μm is formed between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum layer 102c2, consisting of a palladium layer 102f2, a silver layer 102g2, and a gold layer 102e2. The noble metal is at least one of gold, silver, platinum, palladium, rhodium, iridium, ruthenium, and osmium. The noble metal layer contains the noble metal as its main component. The noble metal layer contains, for example, 95 parts by mass or more of the noble metal, which is 95% of the total mass, per 100 parts by mass of the total mass of the noble metal layer. In contrast to the metal material 102R2 according to Reference Embodiment 2, in the metal material 102 according to the embodiment, only a copper-containing layer 102b1 is formed between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum group-containing layer 102c. The copper-containing layer 102b1 is not a precious metal layer. Therefore, in this embodiment, the platinum group metal-containing layer 102c covers the base material 102a without a precious metal layer thicker than 1.0 μm between the base material 102a and the platinum group metal-containing layer 102c. Thus, in the metal material 102 according to this embodiment, the structure of the metal layer between the base material 102a and the platinum group metal-containing layer 102c can be simplified compared to the metal material 102R2 according to Reference Embodiment 2, and the base material 102a can be covered with the platinum group metal-containing layer 102c in a simple configuration. Therefore, in this embodiment, compared to Reference Embodiment 2, the manufacturing time and cost for covering the base material 102a with the platinum group metal-containing layer 102c can be reduced. Furthermore, in this embodiment, compared to Reference Embodiment 2, the thickness of the metal layer including the copper-containing layer 102b1 and the platinum group metal-containing layer 102c formed on the surface of the base material 102a can be reduced, making it easier to reduce dimensional errors caused by the metal layer formed on the surface of the base material 102a.

[0054] A relatively thin precious metal layer of 1.0 μm or less may be located between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum group metal-containing layer 102c. For example, the precious metal layer of 1.0 μm or less may be located in place of at least a portion of the copper-containing layer 102b1. Alternatively, the precious metal layer of 1.0 μm or less may be located between the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a, or between the upper surface on the +Z side of the copper-containing layer 102b1 and the lower surface on the -Z side of the platinum group metal-containing layer 102c. When the precious metal layer of 1.0 μm or less is located between the upper surface on the +Z side of the copper-containing layer 102b1 and the lower surface on the -Z side of the platinum group metal-containing layer 102c, the precious metal layer of 1.0 μm or less may function as a barrier layer to prevent the diffusion of copper (B1) into the platinum group metal-containing layer 102c.

[0055] When a noble metal layer of 1.0 μm or less is located between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum group metal-containing layer 102c, the corrosion resistance of the metal material 102 can be improved by the noble metal layer of 1.0 μm or less. Therefore, even if the thickness of the platinum group metal-containing layer 102c is relatively thin, for example, 0.3 μm, the corrosion resistance of the metal material 102 can be maintained. That is, when a noble metal layer of 1.0 μm or less is located between the lower surface on the -Z side of the copper-containing layer 102b1 and the upper surface on the +Z side of the base material 102a, the thickness of the platinum group metal-containing layer 102c may be 0.3 μm or more. Even if the precious metal layer is located between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum group metal-containing layer 102c, by making the thickness of the precious metal layer relatively thin, such as 1.0 μm or less, the base material 102a can be covered with the platinum group metal-containing layer 102c in a simpler configuration compared to the case where the precious metal layer is thicker than 1.0 μm between the upper surface on the +Z side of the base material 102a and the lower surface on the -Z side of the platinum group metal-containing layer 102c.

[0056] In one example, if a noble metal layer of 1.0 μm or less is located between the upper surface on the +Z side of the copper-containing layer 102b1 and the lower surface on the -Z side of the platinum group metal-containing layer 102c, the thickness of the platinum group metal-containing layer 102c may be 0.3 μm or more. In this example, the noble metal layer of 1.0 μm or less may have at least one layer of platinum and gold. In this example as well, the corrosion resistance of the metal material 102 can be improved by the noble metal layer of 1.0 μm or less. Therefore, even if the thickness of the platinum group metal-containing layer 102c is relatively thin, for example, 0.3 μm, the corrosion resistance of the metal material 102 can be maintained.

[0057] Figure 7 shows a metal material 102A according to Modification 1. The metal material 102A according to Modification 1 is the same as the metal material 102 according to the embodiment, except for the following points.

[0058] The metal material 102A according to Modification 1 has a copper alloy-containing layer 102b2 instead of the copper-containing layer 102b1 according to the embodiment. The copper alloy-containing layer 102b2 mainly contains a copper alloy (B2). The copper alloy (B2) mainly contains copper. The copper alloy-containing layer 102b2 contains, for example, 50% of the total mass, or 50 parts by mass or more, of copper per 100 parts by mass, which is the total mass of the copper alloy-containing layer 102b2. Examples of copper alloy (B2) include copper-tin alloy, brass, beryllium copper, bronze, and phosphor bronze. The thickness of the copper alloy-containing layer 102b2 according to Modification 1 can be determined in the same manner as described for the thickness of the copper-containing layer 102b1 according to the embodiment.

[0059] Between the base material 102a and the platinum group metal-containing layer 102c, there may be at least one copper-containing layer corresponding to the copper-containing layer 102b1 according to the embodiment, and at least one copper alloy-containing layer corresponding to the copper alloy-containing layer 102b2 according to Modified Example 1. In other words, between the base material 102a and the platinum group metal-containing layer 102c, there may be a layer containing at least one of copper and a copper alloy as the main component.

[0060] In Modification 1, as in the embodiment, the corrosion resistance of the metal material 102A can be improved by the platinum group metal-containing layer 102c. Furthermore, as in the embodiment, the base material 102a can be covered with the platinum group metal-containing layer 102c in a simple configuration. In Modification 1, the copper alloy-containing layer 102b2 is located between the base material 102a and the platinum group metal-containing layer 102c. The copper alloy-containing layer 102b2 is not a precious metal layer. Therefore, in Modification 1, the platinum group metal-containing layer 102c covers the base material 102a without a precious metal layer thicker than 1.0 μm being present between the base material 102a and the platinum group metal-containing layer 102c. Thus, in Modification 1, the base material 102a can be covered with the platinum group metal-containing layer 102c in a simpler configuration compared to the case where a precious metal layer thicker than 1.0 μm is located between the base material 102a and the platinum group metal-containing layer 102c.

[0061] The layer located between the base material 102a and the platinum group metal-containing layer 102c is not limited to the copper-containing layer 102b1 and the copper alloy-containing layer 102b2 according to the embodiment. The layer located between the base material 102a and the platinum group metal-containing layer 102c may be at least one layer mainly containing, for example, tin, tin alloy, silver, silver alloy, iron, stainless steel, aluminum, and aluminum alloy. Examples of stainless steel include SUS304, SUS316L, or SUS430. Examples of aluminum alloy include A6061.

[0062] Figure 8 shows a metal material 102B according to Modification 2. The metal material 102B according to Modification 2 is the same as the metal material 102 according to the embodiment, except for the following points.

[0063] The metal material 102B according to Modification 2 does not have a layer corresponding to the copper-containing layer 102b1 according to the embodiment. The platinum group metal-containing layer 102c according to Modification 2 directly covers the upper surface of the base material 102a on the +Z side. The statement that the platinum group metal-containing layer 102c directly covers the upper surface of the base material 102a on the +Z side means that the upper surface of the base material 102a on the +Z side and the lower surface of the platinum group metal-containing layer 102c on the -Z side are in direct contact with each other, in a state where no layer other than the base material 102a and the platinum group metal-containing layer 102c is located between the upper surface of the base material 102a on the +Z side and the lower surface of the platinum group metal-containing layer 102c on the -Z side.

[0064] In the modified example 2, the corrosion resistance of the metal material 102B can be improved by the platinum group metal-containing layer 102c, similar to the embodiment. Furthermore, similar to the embodiment, the base material 102a can be covered with the platinum group metal-containing layer 102c with a simpler configuration compared to the case where a noble metal layer thicker than 1.0 μm is located between the base material 102a and the platinum group metal-containing layer 102c.

[0065] The embodiments and modifications of the present invention have been described above with reference to the drawings, but these are merely examples of the present invention, and various other configurations can also be adopted.

[0066] One aspect of the present invention will be described based on an example. The present invention is not limited to the following examples.

[0067] (Example 1) The metal material according to Example 1 was manufactured as follows. The metal material according to Example 1 corresponds to the metal material 102 according to the embodiment.

[0068] First, a brass base material was prepared. This base material corresponds to base material 102a according to the embodiment. Next, a copper layer with a thickness of 2 μm was formed on the surface of the base material by plating. This copper layer corresponds to copper-containing layer 102b1 according to the embodiment. Next, a platinum layer with a thickness of 0.7 μm to 4 μm was formed on the surface of the copper layer by plating. This platinum layer corresponds to platinum group metal-containing layer 102c according to the embodiment.

[0069] The metal material according to Reference Example 1 was manufactured as follows. The metal material according to Reference Example 1 corresponds to the metal material 102R1 according to Reference Form 1.

[0070] First, a brass base material was prepared. This base material corresponds to base material 102a in Reference Form 1. Next, a nickel layer with a thickness of 4.5 μm was formed on the surface of the base material by plating. This nickel layer corresponds to nickel layer 102d1 in Reference Form 1. Next, a gold layer with a thickness of 1.3 μm was formed on the surface of the nickel layer by plating. This gold layer corresponds to gold layer 102e1 in Reference Form 1.

[0071] The metal material according to Reference Example 2 was manufactured as follows. The metal material according to Reference Example 2 corresponds to the metal material 102R2 according to Reference Form 2.

[0072] First, a brass base material was prepared. This base material corresponds to base material 102a according to Reference Form 2. Next, a palladium layer with a thickness of 0.3 μm was formed on the surface of the base material by plating. This palladium layer corresponds to palladium layer 102f2 according to Reference Form 2. Next, a silver layer with a thickness of 2.4 μm was formed on the surface of the palladium layer by plating. This silver layer corresponds to silver layer 102g2 according to Reference Form 2. Next, a gold layer with a thickness of 1.5 μm was formed on the surface of the silver layer by plating. This gold layer corresponds to gold layer 102e2 according to Reference Form 2. Next, a platinum layer with a thickness of 0.4 μm was formed on the surface of the gold layer by plating. This platinum layer corresponds to platinum layer 102c2 according to Reference Form 2.

[0073] Electrolytic corrosion tests were conducted on the metal materials related to Example 1, Reference Example 1, and Reference Example 2. In the electrolytic corrosion test, the electrodes and metal materials were immersed in Pickering's artificial sweat, ISO 3160, at a distance of 10 mm, and the anode of a DC power supply was connected to the electrodes. With the cathode of the DC power supply connected to the metal materials, a current of 1 mA at a DC voltage of 5 V was applied to the electrodes and metal materials for 10 minutes using the DC power supply.

[0074] In the metal material according to Reference Example 1, corrosion occurred in the electrolytic corrosion test. In contrast to the metal material according to Reference Example 1, no corrosion occurred in the metal materials according to Example 1 and Reference Example 2. Comparing the results of the electrolytic corrosion test of the metal material according to Reference Example 1 with the results of the electrolytic corrosion test of the metal materials according to Example 1 and Reference Example 2, it can be said that covering the base material with a platinum layer improves its resistance to electrolytic corrosion.

[0075] (Example 2) Table 1 shows the conditions for forming the platinum layer in Samples 1 to 11 according to Example 2. In the "Sample" column of Table 1, "1" to "11" represent Samples 1 to 11, respectively. Table 1 shows "Current Density (A / dm²) ２ The values ​​in the column ) represent the electrolytic plating current density (unit: A / dm²) required to form the platinum layer in each sample. ２Table 1 shows the following. In the "Plating Solution" column of Table 1, "A", "B", and "C" indicate the type of plating solution used for electroplating to form the platinum layer in each sample. Hereinafter, plating solution A, plating solution B, and plating solution C refer to the plating solution labeled "A", "B", and "C" in the "Plating Solution" column of Table 1, respectively. Plating solutions A, B, and C were as follows. In samples 1 to 11, the thickness of the platinum layer was adjusted by adjusting the electroplating time for forming the platinum layer. Plating solution A: pH 1.5, platinum concentration 15 g / L, sulfuric acid 5-10% Plating solution B: pH 0.5, platinum concentration 10 g / L, sulfuric acid 7-9% Plating solution C: pH 0.5, platinum concentration 15 g / L, sulfuric acid 5-9%

[0076]

[0077] Sample 1 was prepared as follows. Sample 1 corresponds to the metal material 102 according to the embodiment.

[0078] First, a brass base material was prepared. This base material corresponds to base material 102a according to the embodiment. Next, a copper layer with a thickness of 2 μm was formed on the surface of the base material by plating. This copper layer corresponds to copper-containing layer 102b1 according to the embodiment. Next, as shown in Table 1, plating solution A was used with a current density of 2.0 A / dm ２ A platinum layer was formed on the surface of the copper layer by electroplating. This platinum layer corresponds to the platinum group metal-containing layer 102c according to the embodiment.

[0079] Samples 2 to 11 were prepared in the same manner as Sample 1, except that the current density and plating solution for electroplating to form the platinum layer were as shown in Table 1, and the thickness of the platinum layer was adjusted by adjusting the electroplating time for each sample.

[0080] Table 2 shows the relationship between the thickness (in μm), crystallite size (in nm), residual stress (in MPa), crystal plane ratios (in %) for the (200), (220), and (222) planes, and the corrosion start time (in hours) for samples 1 to 11 in Example 2. In the "Sample" column of Table 2, "1" to "11" represent samples 1 to 11, respectively.

[0081]

[0082] The thickness of each sample was measured by SEM observation. The thickness of each sample is shown in the "Thickness (μm)" column of Table 2.

[0083] Using a Bruker D8 Discover X-ray diffractometer, the crystallite size of the platinum layer in each sample was calculated using the Whole Powder Pattern Deconvolution (WPPD) method from the X-ray diffraction spectra of the platinum layer in the range of 2θ = 20° to 2θ = 105°. The crystallite sizes of the platinum layer in each sample are shown in the "Crystallite Size (nm)" column of Table 2.

[0084] Using a Bruker D8 Discover X-ray diffractometer, the residual stress of the platinum layer in each sample was measured by a two-dimensional stress analysis method under the following conditions. The residual stress for each sample is shown in the "Residual Stress (MPa)" column of Table 2. X-ray wavelength: Cu-Kα1 X-ray collimator diameter: 0.5 mm Diffraction angle 2θ: 81.8° Sample rotation angle Φ: 0°, 30°, 60°, 90°, 120°, 150°, 180° Sample tilt angle Ψ: 15°, 45° 1 frame time: 120 seconds Crystal plane: Pt(311) Poisson's ratio: 0.380 Young's modulus: 168000 MPa The rotation angle Φ is the rotation angle of the sample around the Z axis perpendicular to the sample surface. A rotation angle of Φ of 0° refers to the direction indicated by the X-axis perpendicular to the Z-axis, and a rotation angle of Φ of the sample of 90° refers to the direction indicated by the Y-axis perpendicular to both the Z-axis and the X-axis. The inclination angle Ψ is the inclination angle of the sample around the X-axis. With a diffraction angle 2θ of 81.8°, measurements were performed at each of the 14 points corresponding to the seven rotation angles for rotation angle Φ and the two inclination angles for inclination angle Ψ, for a frame time of 120 seconds.

[0085] Hereinafter, the ratio of (200) faces in each sample refers to the ratio of (200) faces to the sum of (200) faces, (220) faces, and (222) faces in the platinum layer of each sample. Hereinafter, the ratio of (220) faces in each sample refers to the ratio of (220) faces to the sum of (200) faces, (220) faces, and (222) faces in the platinum layer of each sample. Hereinafter, the ratio of (222) faces in each sample refers to the ratio of (222) faces to the sum of (200) faces, (220) faces, and (222) faces in the platinum layer of each sample.

[0086] Using a Bruker D8 Discover X-ray diffractometer, the ratio of the integral value of the (200) plane peak to the sum of the integral values ​​of the (200) plane peaks, (220) plane peaks, and (222) plane peaks in the X-ray diffraction spectrum of the platinum layer of each sample in the range of 2θ = 25° to 2θ = 100° was calculated as the (200) plane ratio for each sample. The (200) plane ratio for each sample is shown in the "(200) plane" column of "Crystal Plane Ratio (%)" in Table 2.

[0087] Using a Bruker D8 Discover X-ray diffractometer, the ratio of the integral value of the (220) plane peak to the sum of the integral values ​​of the (200) plane peak, the (220) plane peak, and the (222) plane peak in the X-ray diffraction spectrum of the platinum layer of each sample in the range from 2θ = 25° to 2θ = 100° was calculated as the (220) plane ratio for each sample. The (220) plane ratio for each sample is shown in the "(220) plane" column of "Crystal Plane Ratio (%)" in Table 2.

[0088] Using a Bruker D8 Discover X-ray diffractometer, the ratio of the (222) plane peak to the sum of the integral values ​​of the (200), (220), and (222) plane peaks in the X-ray diffraction spectra of the platinum layer of each sample in the range from 2θ = 25° to 2θ = 100° was calculated as the (222) plane ratio for each sample. The (222) plane ratio for each sample is shown in the "(222) plane" column of "Crystal Plane Ratio (%)" in Table 2.

[0089] In the immersion test using bleach, the time from immersion in the bleach until corrosion of each sample began was measured. The bleach used was CLOROX Bleach. Specifically, first, the sample was placed in a 5 ml vial. Next, 100 μl of bleach was measured using a micropipette and added to the vial, and the sample was immersed in the bleach. Then, 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, 144 hours, and 168 hours after immersion in the bleach, the sample was removed from the vial and washed. Next, the sample was observed using a microscope and SEM to confirm the presence or absence of corrosion. In Table 2, the values ​​in the "Bleach" column of "Corrosion Initiation Time (hours)" indicate the time from immersion in the bleach until removal from the vial for samples in which corrosion was confirmed. In Table 2, the "-" in the "Bleach" column under "Corrosion Initiation Time (hours)" indicates that no corrosion occurred in the sample after 168 hours of immersion.

[0090] In an immersion test using quaternary ammonium chloride (quaternary ammonium chloride), the time from immersion in quaternary ammonium chloride to the onset of corrosion of each sample was measured. Specifically, first, the sample was placed in a 5 ml vial. Next, Sani-Cloth® containing quaternary ammonium chloride was prepared, and the quaternary ammonium chloride was squeezed from the Sani-Cloth® into a petri dish. Next, 100 μl of quaternary ammonium chloride was measured using a micropipette and placed in the vial, and the sample was immersed in the quaternary ammonium chloride. Next, the sample was removed from the vial and washed 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, 144 hours, and 168 hours after immersion in quaternary ammonium chloride. Next, the sample was observed using a microscope and SEM to confirm the presence or absence of corrosion. The values ​​in the "Quats" column under "Corrosion Initiation Time (hours)" in Table 2 indicate the time from when the sample showing corrosion was immersed in quats until it was removed from the vial. A "-" in the "Quats" column under "Corrosion Initiation Time (hours)" in Table 2 indicates that no corrosion occurred in the sample during 168 hours of immersion.

[0091] In the immersion test using artificial sweat, the time from immersion in artificial sweat to the start of corrosion of each sample was measured. The artificial sweat used was Pickering's ISO 3160 artificial sweat. Specifically, first, the sample was placed in a 5 ml vial. Next, 100 μl of artificial sweat was measured using a micropipette and placed in the vial, and the sample was immersed in the artificial sweat. Then, 24 hours, 48 ​​hours, 72 hours, 96 hours, 120 hours, 144 hours, and 168 hours after immersion in artificial sweat, the sample was removed from the vial and washed. Next, the sample was observed using a microscope and SEM to check for the presence or absence of corrosion. In Table 2, the values ​​in the "Artificial Sweat" column under "Corrosion Initiation Time (hours)" indicate the time from immersion in artificial sweat to removal from the vial for samples in which corrosion was confirmed. In Table 2, the "-" in the "Artificial Sweat" column under "Corrosion Initiation Time (hours)" indicates that no corrosion occurred in the sample after 168 hours of immersion.

[0092] Comparing samples 1-6 and 7-11 in Table 2, it was found that when the platinum layer thickness was 0.7 μm or more and the crystallite size of the platinum layer was 20.0 nm or more, corrosion caused by immersion in bleach, quats, and artificial sweat was suppressed. Therefore, it can be said that a platinum layer thickness of 0.7 μm or more and a crystallite size of 20.0 nm or more are preferable.

[0093] In Table 2, the residual stress of the platinum layer in samples 7 to 11 is between 300 MPa and 1200 MPa. No corrosion occurred in samples 7 to 11 due to immersion in bleach, quats, and artificial sweat, the thickness of the platinum layer was 0.7 μm or more, and the crystallite size of the platinum layer was 20.0 nm or more. Therefore, it can be said that when the thickness of the platinum layer is 0.7 μm or more and the crystallite size of the platinum layer is 20.0 nm or more, the residual stress of the platinum layer can be between 300 MPa and 1200 MPa.

[0094] In Table 2, for samples 7 to 11, the proportion of (200) planes in each sample was 2.5% to 30.0%, the proportion of (220) planes in each sample was 40.0% to 95.0%, and the proportion of (222) planes in each sample was 2.5% to 30.0%. No corrosion occurred in samples 7 to 11 due to immersion in bleach, quats, and artificial sweat, the thickness of the platinum layer was 0.7 μm or more, and the crystallite size of the platinum layer was 20.0 nm or more. Therefore, it can be said that when the thickness of the platinum layer is 0.7 μm or more and the crystallite size of the platinum layer is 20.0 nm or more, the proportion of (200) planes to the sum of (200), (220), and (222) planes in the platinum layer can be 2.5% to 30.0%. Furthermore, the ratio of the (220) facet to the sum of the (200), (220), and (222) facets in the platinum layer can be said to be between 40.0% and 95.0%. In addition, the ratio of the (222) facet to the sum of the (200), (220), and (222) facets in the platinum layer can be said to be between 2.5% and 30.0%.

[0095] (Example 3) The metal material according to Example 3 was manufactured as follows. The metal material according to Example 3 corresponds to the metal material 102 according to the embodiment.

[0096] First, a brass base material was prepared. This base material corresponds to base material 102a according to the embodiment. Next, a copper layer with a thickness of 2.0 μm was formed on the surface of the base material by plating. This copper layer corresponds to the copper-containing layer 102b1 according to the embodiment. Next, a platinum layer with a thickness of 0.1 μm was formed on the surface of the copper layer by plating. Next, a gold layer with a thickness of 0.9 μm was formed on the surface of the platinum layer by plating. The platinum layer with a thickness of 0.1 μm and the gold layer with a thickness of 0.9 μm correspond to the precious metal layer of 1.0 μm or less according to the embodiment. Next, a platinum layer with a thickness of 0.3 μm was formed on the surface of the gold layer by plating. The platinum layer with a thickness of 0.3 μm corresponds to the platinum group metal-containing layer 102c according to the embodiment.

[0097] For the metal material according to Example 3, an electrolytic corrosion test was performed under the same conditions as the electrolytic corrosion test described in Example 1. For the metal material according to Example 3, an immersion test was performed under the same conditions as the immersion test using bleach described in Example 2, an immersion test under the same conditions as the immersion test using quats described in Example 2, and an immersion test under the same conditions as the immersion test using artificial sweat described in Example 2.

[0098] In the metal material according to Example 3, no corrosion occurred in the electrolytic corrosion test. In the metal material according to Example 3, no corrosion occurred in the metal material after 168 hours of immersion in immersion tests using bleach, quats, and artificial sweat. Therefore, it can be said that the corrosion resistance of the metal material can be improved by a platinum layer with a thickness of 0.1 μm and a gold layer with a thickness of 0.9 μm. Thus, it can be said that the corrosion resistance of the metal material can be maintained even if the thickness of the outermost platinum layer is relatively thin at 0.3 μm.

[0099] This specification provides metal materials, contact terminals and connectors in the following embodiments: (Embodiment 1) In embodiment 1, the metal material comprises a base material and a platinum group metal-containing layer, wherein the platinum group metal-containing layer covers the base material in a state where no precious metal layer thicker than 1.0 μm exists between the base material and the platinum group metal-containing layer, or where a precious metal layer of 1.0 μm or less is located between the base material and the platinum group metal-containing layer.

[0100] According to the above embodiment, the corrosion resistance of the metal material can be improved by the platinum group metal-containing layer. Furthermore, compared to the case where a precious metal layer thicker than 1.0 μm is located between the base material and the platinum group metal-containing layer, the base material can be covered with the platinum group metal-containing layer with a simpler structure.

[0101] (Aspect 2) In aspect 2, the metal material further comprises a layer located between the base material and the platinum group metal-containing layer, the layer containing at least one of copper and a copper alloy as its main component.

[0102] According to the above-described embodiment, with a layer containing at least one of copper and a copper alloy as the main component located between the base material and the platinum group metal-containing layer, the corrosion resistance of the metal material can be improved in the same manner as in Embodiment 1, and the base material can be covered with the platinum group metal-containing layer in a simple configuration.

[0103] (Aspect 3) In aspect 3, the thickness of the platinum group metal-containing layer is 0.7 μm or more.

[0104] According to the above embodiment, the corrosion resistance of the metal material can be improved by the corrosion resistance of the platinum group metal-containing layer itself.

[0105] (Aspect 4) In aspect 4, the noble metal layer of 1.0 μm or less is located between the base material and the platinum group metal-containing layer.

[0106] According to the above embodiment, the corrosion resistance of the metal material can be improved by the precious metal layer.

[0107] (Aspect 5) In aspect 5, the thickness of the platinum group metal-containing layer is 0.3 μm or more.

[0108] According to the above embodiment, the corrosion resistance of the metal material can be improved by the precious metal layer, so even if the thickness of the platinum group metal-containing layer is relatively thin at 0.3 μm, the corrosion resistance of the metal material can be maintained.

[0109] (Aspect 6) In aspect 6, the crystallite size of the platinum group metal-containing layer is 20.0 nm or larger.

[0110] According to the above-described embodiment, the corrosion resistance of the metal material can be improved by making the crystallite size of the platinum group metal-containing layer 20.0 nm or larger.

[0111] (Aspect 7) In aspect 7, the thickness of the platinum group metal-containing layer is 0.7 μm or more, and the crystallite size of the platinum group metal-containing layer is 20.0 nm or more.

[0112] According to the above-described embodiment, the corrosion resistance of the metal material can be improved by setting the thickness of the platinum group metal-containing layer to 0.7 μm or more and the crystallite size of the platinum group metal-containing layer to 20.0 nm or more.

[0113] (Aspect 8) In aspect 8, the residual stress of the platinum group metal-containing layer is 300 MPa or more and 1200 MPa or less.

[0114] (Aspect 9) In aspect 9, the ratio of the (200) plane to the sum of the (200), (220), and (222) planes of the platinum group metal-containing layer is 2.5% or more and 30.0% or less, the ratio of the (220) plane to the sum of the (200), (220), and (222) planes of the platinum group metal-containing layer is 40.0% or more and 95.0% or less, and the ratio of the (222) plane to the sum of the (200), (220), and (222) planes of the platinum group metal-containing layer is 2.5% or more and 30.0% or less.

[0115] (Aspect 10) In aspect 10, there is no nickel component between the base material and the platinum group metal-containing layer.

[0116] According to the above-described embodiment, the metal material can be nickel-free. Therefore, the metal material can be easily used for components that come into contact with the skin, such as wearable devices.

[0117] (Aspect 11) In aspect 11, the contact terminal is electrically connected to the object to be connected and comprises the metal material described above.

[0118] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 1, and the base material can be covered with a platinum group metal-containing layer in a simple configuration.

[0119] (Aspect 12) In aspect 12, the connector is provided with the contact terminals described above.

[0120] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 1, and the base material can be covered with a platinum group metal-containing layer in a simple configuration.

[0121] (Aspect 13) In aspect 13, the metal material comprises a base material, a platinum group metal-containing layer, and a layer containing at least one of copper and a copper alloy as the main component, wherein the platinum group metal-containing layer covers the base material with the layer containing at least one of copper and the copper alloy as the main component positioned between the base material and the platinum group metal-containing layer.

[0122] According to the above embodiment, the corrosion resistance of the metal material can be improved by the platinum group metal-containing layer.

[0123] (Aspect 14) In aspect 14, the metal material further comprises a noble metal layer of 1.0 μm or less located between the platinum group metal-containing layer and the layer containing at least one of the copper and copper alloy as its main component.

[0124] According to the above embodiment, the corrosion resistance of the metal material can be improved by the precious metal layer.

[0125] (Aspect 15) In aspect 15, the contact terminal is electrically connected to the object to be connected and comprises the metal material described above.

[0126] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 13.

[0127] (Aspect 16) In aspect 16, the connector is provided with the contact terminals described above.

[0128] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 13.

[0129] (Aspect 17) In aspect 17, the metal material comprises a base material, a platinum group metal-containing layer, and a layer without nickel components, wherein the platinum group metal-containing layer covers the base material with the layer without nickel components positioned between the base material and the platinum group metal-containing layer.

[0130] According to the above embodiment, the corrosion resistance of the metal material can be improved by the platinum group metal-containing layer. Furthermore, the metal material can be made nickel-free. Therefore, the metal material can be easily used in components that come into contact with the skin, such as wearable devices.

[0131] (Aspect 18) In aspect 18, the contact terminal is electrically connected to the object to be connected and comprises the metal material described above.

[0132] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 17, and the metal material can be nickel-free.

[0133] (Aspect 19) In aspect 19, the connector is provided with the contact terminals described above.

[0134] According to the above-described embodiment, the corrosion resistance of the metal material can be improved in the same manner as in embodiment 17, and the metal material can be nickel-free.

[0135] This application claims priority based on Japanese Patent Application No. 2024-168400, filed on 27 September 2024, and incorporates all of its disclosures herein.

[0136] 10 Connector, 20 Circuit board, 100 Contact terminals, 102, 102A, 102B, 102R1, 102R2 Metal material, 102a Base material, 102b1 Copper-containing layer, 102b2 Copper alloy-containing layer, 102c Platinum group metal-containing layer, 102c2 Platinum layer, 102d1 Nickel layer, 102e1, 102e2 Gold layer, 102f2 Palladium layer, 102g2 Silver layer, 110 Head, 120 Tapered section, 130 Column section, 140 Tip section, 200 Housing, 300 Guide pin

Claims

1. A metallic material comprising a base material and a platinum group metal-containing layer, wherein the platinum group metal-containing layer covers the base material in a state where no precious metal layer thicker than 1.0 μm exists between the base material and the platinum group metal-containing layer, or where a precious metal layer of 1.0 μm or less is located between the base material and the platinum group metal-containing layer.

2. The metal material according to claim 1, further comprising a layer located between the base material and the platinum group metal-containing layer, the layer containing at least one of copper and a copper alloy as its main component.

3. The metal material according to claim 1, wherein the thickness of the platinum group metal-containing layer is 0.7 μm or more.

4. The metal material according to claim 1, wherein the noble metal layer of 1.0 μm or less is located between the base material and the platinum group metal-containing layer.

5. The metal material according to claim 4, wherein the thickness of the platinum group metal-containing layer is 0.3 μm or more.

6. The metal material according to claim 1, wherein the crystallite size of the platinum group metal-containing layer is 20.0 nm or larger.

7. The metal material according to claim 1, wherein the thickness of the platinum group metal-containing layer is 0.7 μm or more, and the crystallite size of the platinum group metal-containing layer is 20.0 nm or more.

8. The metal material according to claim 1, wherein the residual stress of the platinum group metal-containing layer is 300 MPa or more and 1200 MPa or less.

9. The metal material according to claim 1, wherein the ratio of (200) planes to the sum of (200) planes, (220) planes, and (222) planes of the platinum group metal-containing layer is 2.5% or more and 30.0% or less, the ratio of (220) planes to the sum of (200) planes, (220) planes, and (222) planes of the platinum group metal-containing layer is 40.0% or more and 95.0% or less, and the ratio of (222) planes to the sum of (200) planes, (220) planes, and (222) planes of the platinum group metal-containing layer is 2.5% or more and 30.0% or less.

10. The metal material according to claim 1, wherein no nickel component is present between the base material and the platinum group metal-containing layer.

11. A contact terminal that is electrically connected to an object to be connected, comprising the metal material described in any one of claims 1 to 10.

12. A connector comprising the contact terminals described in claim 11.

13. A metallic material comprising: a base material; a platinum group metal-containing layer; and a layer containing at least one of copper and a copper alloy as its main component, wherein the platinum group metal-containing layer covers the base material with the layer containing at least one of copper and the copper alloy as its main component positioned between the base material and the platinum group metal-containing layer.

14. The metal material according to claim 13, further comprising a noble metal layer of 1.0 μm or less located between the platinum group metal-containing layer and the layer containing at least one of the copper and the copper alloy as its main component.

15. A contact terminal that is electrically connected to an object to be connected, comprising the metal material described in claim 13 or 14.

16. A connector comprising the contact terminals described in claim 15.

17. A metallic material comprising a base material, a platinum group metal-containing layer, and a layer free of nickel components, wherein the platinum group metal-containing layer covers the base material with the layer free of nickel components positioned between the base material and the platinum group metal-containing layer.

18. A contact terminal that is electrically connected to an object to be connected, comprising the metal material described in claim 17.

19. A connector comprising the contact terminals described in claim 18.

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