TWI476301B - Fine crystalline and amorphous coexisting gold alloy, plating film, plating solution, and plating method for said film - Google Patents

Description

Microcrystalline-unshaped hybrid gold alloy and coated film using the same, electronic component, plating solution therefor and plating film forming method

The present invention relates to a plating film which is effective as a terminal for an electronic machine part, a fine crystal-unshaped hybrid gold alloy plating film excellent in electrical properties and mechanical properties, and a method capable of forming the fine crystal-deformed An electroplating solution of a mixed gold alloy plating film, and an electroplating method using the electroplating liquid.

In electrical/electronic parts connectors, electromechanical small relays, printed wiring boards, etc., especially as electrical contact materials for parts requiring high reliability, a type of hard material has been widely used. A gold plated film of gold plated film. The hard gold plating film is a material obtained by adding cobalt, nickel, or the like to gold, which does not lower the good electrical conductivity and chemical stability of gold, and can increase the hardness of the film. Such a hard gold plating film is a fine structure having a fine crystal of gold (20 to 30 nm), which can be regarded as a kind of wear resistance required for obtaining a contact material due to such a fine structure. The minimum hardness required for the consumption (Knoop hardness: Hk 170 or so).

On the other hand, in recent years, the size of electrical contacts has been miniaturized with the miniaturization of electronic components. However, the plating film formed in such minute contacts has been reduced in size and thinned. Therefore, it is also required to further increase the hardness upward to obtain high wearability.

Further, in the near future, the size of the contact is necessarily similar to the fine crystal size of the hard gold plating film described above, and when the hard gold plating film as described above is formed on such a fine contact, The absolute number of fine crystals constituting the film is small, and it is expected that durability equivalent to that of the hard gold plating film formed on the joint of the currently applicable size is not obtained. Therefore, the inventors of the present invention have invented an amorphous gold alloy plating film formed by a homogeneous amorphous phase having no fine crystals (for example, Patent Documents 6 to 8). However, it can be said that there is still room for improvement in order to maintain the good specific resistance and chemical stability of gold to the extent that it is practically problem-free and at the same time to increase the hardness.

[Previous Technical Literature]

[Patent Literature]

Further, the related prior art document information of the present invention is as follows.

[Patent Document 1] JP-A-60-33382

[Patent Document 2] JP-A-62-290893

[Patent Document 3] Patent No. 3452724

[Patent Document 4] Patent No. 3983207

[Patent Document 5] JP-A-2004-300483

[Patent Document 6] JP-A-2006-241594

[Patent Document 7] JP-A-2007-92157

[Patent Document 8] JP-A-2007-169706

[Non-patent literature]

[Non-Patent Document 1] Chuan Hehui, "Study on the Precipitation Structure of Gold-Nickel Alloy Plating", Metal Surface Technology, 1968, Vol. 19, Vol. 12, pp. 487-491

[Non-Patent Document 2] Shimizu Kazuo and the other, "Study on Electron Microscopy of Electrodeposited Au-Ni Alloys and Microstructures", Metal Surface Technology, 1976, Vol. 27, Vol. 1, No. 20 -24 pages

[Non-Patent Document 3] Watanabe Thorough, "Control Technology and Analytical Method for Precision Electroplating Coating Structure", Technical Information Society, February 2002, pp. 256-262

[Non-Patent Document 4] Xiao seeong and two others, "High W content and film properties of Ni-W alloy plating film", Metal Surface Technology, 1988, Vol. 39, Vol. 12, No. 809 -812 pages

[Non-Patent Document 5] Watanabe Toru, "Mechanism for Forming Amorphous Alloy by Plating", Surface Technology, 1989, Vol. 40, Vol. 3, pp. 21-26

The present invention has been made in view of the above circumstances, and an object thereof is to provide a fine crystal-non-shaped hybrid gold alloy plating film which is excellent in abrasion resistance and excellent in electrical conductivity and chemical stability while improving hardness. An electroplating solution for forming the fine crystal-deformed mixed gold alloy plating film, and an electroplating method using the electroplating solution.

The present inventors have repeatedly made a careful review in order to achieve the above-mentioned purpose, and based on the preliminary judgment, the fine structure of the plating film which does not reduce the hardness even in the case of minute contacts, although the crystal structure is compared, In terms of the structure of the amorphous phase, it is possible to maintain the good specific resistance and chemical stability of gold to a practically no problem and to simultaneously improve hardness and wear resistance. However, the average free path of electrons is shorter than that of the crystalline film. When the study was conducted with the idea that the electrical conductivity was low and cracking easily occurred on the plating film due to internal stress, it was found that a specific concentration of gold cyanide salt, nickel salt and/or cobalt was used. It is surprising that the salt further preferably contains a compounding agent such as an organic acid, an inorganic acid or a salt thereof, and an electroplating solution having good liquid stability of ammonia or ammonium ions for electrical plating. A fine crystalline-unshaped hybrid gold alloy plating film formed by mixing a fine crystalline phase and an amorphous phase, and the film can maintain the good specific resistance value and chemical stability of gold. Practically useful and can also enhance the degree of hardness, the results of further research and completed embodiment of the present invention.

That is, the present invention provides: (1) a fine crystal-non-shaped hybrid gold alloy plating film which is formed by mixing a fine crystal phase and an amorphous phase, and (2) one containing gold as a basis gold cyanide salt concentration of 0.0001 ~ 0.4 mol / dm ^3, the nickel basis of 0.001 ~ 0.5 mol / dm ³ concentration of the nickel salt, and / or cobalt basis of 0.001 ~ 0.5 mol / concentration of DM ³ The cobalt salt, preferably further containing a concentration of 0.001 to 2.0 mol/dm ^{3 of} an organic acid, a mineral acid or a salt thereof, or a mixture of ammonia or ammonium ions at a concentration of 0.001 to 5.0 mol/dm ³ An electroplating solution having a good liquid stability and (3) an electroplating which is characterized by the use of the electroless plating solution to form a fine crystal-deformed mixed gold alloy plating film on the object to be plated. Application method.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention is formed by mixing a fine crystal phase and an amorphous phase, and as a result, it is a kind which can maintain the good specific resistance value and chemical stability of gold. A material that is practically useful and can increase hardness, so it can be effectively used as a contact material for electrical/electronic parts such as relays. In general, it is known that in the case where the crystal film is composed of fine crystals, although the size of the constituent crystal grains becomes small, the hardness is increased to a certain limit (for example, in the case of nickel: about 4 nm); When the crystal grains are further reduced, the hardness may be lowered. Even in the case of gold, although there is no practical example of whether or not the general theory can be applied, the present invention for the first time to realize a microcrystalline-unshaped hybrid crystal film in gold is confirmed for the first time: fine crystal-deformed hybrid The gold alloy plating film can completely solve such problems as described above, and since the electric conductor is also high and is unlikely to be cracked, it can be sufficiently suitable as an electric/electronic device such as a connector or a relay. The tiny contact material of the part.

Hereinafter, the present invention will be further described in detail.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention is formed by mixing a fine crystal phase and an amorphous phase.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention contains nickel and/or cobalt in gold, and the fine structure is a structure in which a fine crystal phase and an amorphous phase are mixed; It is achieved by special features: better specific resistance and chemical stability, and higher hardness than amorphous non-formed gold alloy plating. Such a structure in which a fine crystal phase and an amorphous phase are mixed may be formed by an X-ray diffraction (XRD) pattern, a transmission electron microscope (TEM) photograph, and a transmissive high-energy electron diffraction (THEED). Photo to confirm.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention preferably has an average particle diameter of fine crystals of 30 nm or less, particularly preferably 20 nm or less, more preferably 15 from the viewpoint of maintaining high hardness. Below nm.

Further, the fine crystal-unshaped hybrid gold alloy plating film of the present invention has high properties from the maintenance of the original properties of gold (good specific resistance and chemical stability) or maintenance of conventional gold or gold alloy plating films. From the viewpoint of hardness, the volume fraction of fine crystals is preferably from 10 to 90%, particularly preferably from 15 to 60%.

According to the present invention, it is possible to obtain a fine crystalline-unshaped hybrid gold alloy plating film having excellent hardness and specific resistance, that is, it is possible to obtain a method having a Knoop hardness of preferably Hk 180 or more; in particular, preferably Hk 220 or more, more preferably Hk 300 or more, particularly preferably Hk 350 or more; further, the specific resistance is preferably 200 μΩ ‧ cm or less, particularly preferably 150 μΩ ‧ cm or less, and particularly preferably 100 μΩ ‧ cm or less. Further, the fine crystal-unshaped hybrid gold alloy plating film of the present invention is a structure in which the fine crystal phase and the amorphous phase are not mixed when the annealing treatment (holding for 1 hour) is performed at 300 ° C or lower (ie, causes The average particle diameter and volume fraction of the fine crystals which are crystallized and enlarged.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention is excellent in specific resistance value and chemical stability, and has the characteristics of high hardness which is not possessed by conventional gold or gold alloy plating films. Therefore, it can be effectively used as a conduction contact for terminals of electrical/electronic parts such as electromagnetic switches, brakes, thermostats, relays, timers, various switches, printed wiring boards, and the like.

The fine crystal-unshaped hybrid gold alloy plating film of the present invention can have a composition formula: Au _100-xy M _x C _y (however, Au or M is a main component, and may contain unavoidable impurities; M system Ni and / Or Co; C is carbon; 1 atom% ≦X≦80 atom%; 1 atom% ≦y≦30 atom%).

The fine crystal-unshaped hybrid gold alloy plating film of the present invention can be formed by electrical plating using an electrical plating solution containing a gold cyanide salt, a nickel salt and/or a cobalt salt.

In the electric plating solution, although it contains a gold cyanide salt, a nickel salt, and/or a cobalt salt, for example, a specific example of the cyanide gold salt may be gold potassium cyanide or sodium gold cyanide. Specific examples of the nickel salt, for example, nickel sulfate, nickel nitrate, etc., and specific examples of the cobalt salt, for example, it may be cobalt sulfate, cobalt nitrate or the like. The concentration of the cyanide gold salt in the plating solution is preferably 0.0001 to 0.4 mol/dm ³ , preferably 0.001 to 0.2 mol/dm ³ , more preferably 0.01 to 0.1 mol/dm ³ , based on gold. The salt concentration, based on nickel, is preferably 0.001 to 0.5 mol/dm ³ , preferably 0.01 to 0.2 mol/dm ³ ; and the cobalt salt concentration is preferably 0.001 to 0.5 mol/dm ³ based on cobalt. It is preferably 0.01 to 0.2 mol/dm ³ . The ratio of gold to nickel and/or cobalt in the plating solution ((Ni + Co) / Au) is preferably in the range of 0.01 to 300, more preferably 1 to 30, in terms of molar ratio.

Moreover, it is preferable that the electrical plating solution further contains a coupling agent. As the reagent for the wrong agent, for example, it may be an organic acid having an wrong cooperation and pH buffering function, an inorganic acid or a salt thereof; and used as an organic acid, an inorganic acid or a salt thereof, For example, it may be citric acid, tartaric acid, malic acid, picolinic acid, phosphoric acid, amine sulfonic acid, and the sodium, potassium, ammonium salts thereof and the like. The concentration of the complexing agent in the plating solution is preferably 0.001 to 2.0 mol/dm ³ ; particularly preferably 0.01 to 1.0 mol/dm ³ , particularly preferably 0.1 to 0.3 mol/dm ³ . The ratio of the complexing agent to the nickel and/or cobalt in the plating solution (the complexing agent / (Ni + Co)) is preferably in the range of 0.01 to 100, more preferably 1 to 4 in terms of the molar ratio.

Further, the electrical plating solution preferably further contains ammonia or ammonium ions. Specific examples of the ammonia or ammonium ion used may be, for example, ammonia water, ammonium sulfate, an ammonium salt of a complexing agent, or the like. The concentration of ammonia or ammonium ions in the plating solution is preferably 0.001 to 5.0 mol/dm ³ , particularly preferably 0.01 to 2.0 mol/dm ³ . This ammonia system is associated with the average particle diameter of the so-called crystal phase, the crystal state of the plating film of the fine crystal (or amorphous) volume fraction, and the stability of the plating bath.

Further, the pH of the electroplating solution is preferably from 3 to 11; in particular, it is preferably pH 5 to 9, more preferably about pH 6. The pH adjustment system can be carried out by using a conventionally known pH adjuster such as ammonia water or potassium hydroxide.

Further, among the electroplating solutions, the physical properties of the coating film (the volume fraction and the average particle diameter of the fine crystal, the peak value of the peak value of the XRD pattern, the Knoop hardness, and the ratio) are not provided. The resistance) and the film composition have a large influence, and may be optionally contained to enhance gloss, prevent dishing, impart conductivity, provide cushioning properties, expand the range of current density that can be used, promote deposition speed, improve heat resistance, and improve wetting. Various additives such as a surfactant and a solvent are used for the purpose of the present invention (for example, Japanese Laid-Open Patent Publication No. Hei 7-11476, JP-A-2004-76026, JP-A-2006-37164).

Although the electroplating conditions are not particularly limited, the plating temperature is preferably 20 to 95 ° C, particularly 50 to 90 ° C. The cathode current density also varies depending on the composition of the plating solution, although not particularly limited, but in a low current density domain (for example, 1 mA/cm ² or more to less than 10 mA/cm ² ) and a high current density domain (for example) Both of them, more than 10 mA/cm ² to 200 mA/cm ² or less, can obtain a fine crystal-deformed mixed gold alloy plating film. Further, an insoluble anode such as platinum may be used on the anode. Further, nickel and/or cobalt may also be used as the anode. On the other hand, as the object to be plated, for example, it may be a metal material such as copper or nickel used for electric wiring or the like. Such a metal material may also be a substance formed on a metal substrate or a non-metal substrate as a base layer. Further, although it may be stirred or not, it is preferable to perform plating under stirring; or, a pulse current may be used to apply a current.

Hereinafter, the present invention will be specifically described by way of examples and comparative examples, but the present invention is not limited to the following examples. Further, in the examples, the methods and conditions for each analysis and measurement are as follows.

[Crystallinity, crystal grain size]

RINT2100-Ultima+: XRD method CuKα (40 kV/4OmA) manufactured by Rigaku Motor Co., Ltd.

Or use the HF-2200: TEM and THEED method made by Hitachi High-Tech Co., Ltd. to accelerate the 200V bright field image

[Volume fraction]

Acceleration voltage 200V bright field image using HF-2200: TEM method and THEED method manufactured by Hitachi High-Tech Co., Ltd.

[Metal composition]

Using the SEA5100: EDXRF method of SII Technology

[Measurement of non-metallic elements]

EMI-920V manufactured by Horiba, Ltd., TC-436 manufactured by LECO, USA

[Nup hardness]

Based on JIS Z 2251, it was measured that the load of 5 gf was held for 30 seconds, and the 30 μm thick plating film formed on the copper plate was measured.

[specific resistance]

K-705RS manufactured by Kyowa Riken Co., Ltd.: based on JIS K 7194 (four-probe method)

[Example 1]

Electrical plating using KAu(CN) ₂ 0.035 mol/dm ³ , NiSO ₄ ‧6H ₂ O 0.076 mol/dm ³ , triammonium citrate 0.21 mol/dm ³ , pH adjusted to 6 with KOH and sulfuric acid The liquid was subjected to a fine crystal-deformed mixed gold alloy plating film (film thickness: 1 μm) on a copper plate having a purity of 99.96% at a current density of 10 mA/cm ² at a temperature of 70 °C. Further, a titanium electrode (mesh) was coated on the anode with platinum; and the plating bath in the plating was vigorously stirred.

A fine crystalline-unshaped hybrid gold alloy plating film obtained by XRD, TEM, and THE ED analysis. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. 2 to 4. It was confirmed that there is a broad peak having a peak crystal half-value width of 1 degree or more peculiar to fine crystal or amorphous in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, it was observed that the crystal grains characteristic of the crystal and the irregular structure unique to the irregular shape were mixed. Further, on the THEED map, it is observed that the diffraction spots unique to the crystal and the hollow rings unique to the amorphous shape are mixed. From this result, it was found that the obtained plating film had a fine crystal-unshaped hybrid structure. Further, as a result of observing the TEM photograph, it was found that the average particle diameter of the fine crystal was 10 nm, and the volume fraction of the fine crystal phase was 50%. On the other hand, composition analysis, Knoop hardness, and specific resistance of the obtained fine crystal-unshaped mixed gold alloy plating film were measured. The detected content ratio: the metal element portion was 41.2 atom% of gold, the nickel was 46.0 atom%, and the non-metal element portion: carbon was 13.8 atom%. The Knoop hardness is Hk 347; the specific resistance is 89 μΩ ‧ cm.

[Embodiment 2]

The plating was performed in the same manner as in Example 1 except that 20 voL of n-propanol was added, and XRD, TEM, and THEED analysis were performed on the obtained plating film. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. 5-7. It was confirmed that there is a broad peak having a peak crystal half-value width of 1 degree or more peculiar to fine crystal or amorphous in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, it was observed that the crystal grains characteristic of the crystal and the irregular structure unique to the irregular shape were mixed. Further, on the THEED chart, it is observed that the diffraction spots unique to the crystal and the hollow rings unique to the amorphous shape are mixed. From this result, it was found that the obtained plating film had a fine crystal-unshaped hybrid structure. Further, as a result of observing the TEM photograph, it was found that the average particle diameter of the fine crystal was 10 nm, and the volume fraction of the fine crystal phase was 50%. On the other hand, composition analysis, Knoop hardness, and specific resistance of the obtained fine crystal-unshaped mixed gold alloy plating film were measured. The detected content ratio: the metal element portion was 48.1 atom% for gold and 38.1 atom% for nickel. Non-metallic element portion: carbon is 12.8 atom%. The Knoop hardness is Hk 348; the specific resistance is 89 μΩ‧cm.

[Example 3]

Except that the citric acid concentration was set to 0.143 mol/dm ³ , the ammonia concentration was set to 1.2 mol/dm ³ , the current density was 1 mA/cm ² (the energization time was 50 seconds), and the 10 mA/cm ² (the energization time was 5 seconds). Electroplating was carried out in the same manner as in Example 1 except that electrolytic plating was alternately performed, and XRD, TEM, and THEED analysis were performed on the obtained plating film. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. 8-10. It was confirmed that there is a broad peak having a peak crystal half-value width of 1 degree or more peculiar to fine crystal or amorphous in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, it was observed that the crystal grains characteristic of the crystal and the irregular structure unique to the irregular shape were mixed. Further, on the THEED chart, it is observed that the diffraction spots unique to the crystal and the hollow rings unique to the amorphous shape are mixed. In the case of constant current plating, only a crystalline phase was obtained at a current density of 1 mA/cm ² , and only an amorphous phase was obtained at 10 mA/cm ² . From this result, it is understood that the plating film obtained by pulse plating has a fine crystal-unshaped hybrid structure. Further, as a result of observing the TEM photograph, it was found that the average particle diameter of the fine crystals was 10 nm, and the volume fraction of the fine crystal phase was 60%. On the other hand, the obtained plating film was subjected to composition analysis, Knoop hardness, and specific resistance measurement. The detected content ratio: the metal element portion was 47.4 atom% in gold and 47.0 atom% in nickel. Non-metallic element portion: carbon is 5.6 atom%. The Knoop hardness is Hk 222; the specific resistance is 57 μΩ ‧ cm.

[Example 4]

Plating was carried out in the same manner as in Example 1 except that the citric acid concentration was set to 0.143 mol/dm ³ , the ammonia concentration was set to 1.2 mol/dm ³ , and the current density was set to 50 mA/cm ² , and the obtained amorphous gold was obtained. The alloy plating film was annealed at an annealing temperature (heating temperature) of 400 ° C, a heating rate of 10 ° C / min, and kept for 1 hour under an atmospheric atmosphere, and the obtained plating film was subjected to XRD, TEM, and T HEED analysis. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. 11-13. It was confirmed that there is a broad peak having a peak crystal half-value width of 1 degree or more peculiar to fine crystal or amorphous in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, it was observed that the crystal grains characteristic of the crystal and the irregular structure unique to the irregular shape were mixed. Further, on the THEED map, it is observed that the diffraction spots unique to the crystal and the hollow rings unique to the amorphous shape are mixed. From this result, it was found that the obtained plating film had a fine crystal-unshaped hybrid structure. Further, as a result of observing the TEM photograph, it was found that the average particle diameter of the fine crystal was 15 nm, and the volume fraction of the fine crystal phase was 60%.

[Example 5]

It contains KAu(CN) ₂ 0.035 mol/dm ³ , CoSO ₄ ‧7H ₂ O 0.076 mol/dm ³ , citric acid ‧H ₂ O 0.1 mol/dm ³ , ammonia concentration 0.44 mol/dm ³ and KOH And an electroless plating solution adjusted to pH 6 by sulfuric acid, and a fine crystal-non-shaped mixed gold alloy plating film (film thickness 1 μm) was formed on a copper plate having a purity of 99.96% at a current density of 10 mA/cm ² at a temperature of 70 ° C. ). Further, a titanium electrode (mesh) was coated on the anode with platinum; and the plating bath in the plating was vigorously stirred.

A fine crystalline-unshaped hybrid gold alloy plating film obtained by XRD, TEM, and THEED analysis. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. It was confirmed that there is a broad peak having a peak crystal half-value width of 1 degree or more peculiar to fine crystal or amorphous in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, it was observed that the crystal grains characteristic of the crystal and the irregular structure unique to the irregular shape were mixed. Further, on the THEED chart, it is observed that the diffraction spots unique to the crystal and the hollow rings unique to the amorphous shape are mixed. From this result, it was found that the obtained plating film had a fine crystal-unshaped hybrid structure. Further, as a result of observing the TEM photograph, it was found that the average particle diameter of the fine crystals was 5 nm, and the volume fraction of the fine crystal phase was 15%. On the other hand, the composition analysis and the Knoop hardness of the obtained fine crystal-unshaped mixed gold alloy plating film were measured. The detected content ratio: the metal element portion was 36.4 atom% of gold, the cobalt was 40.6 atom%, and the non-metal element portion: carbon was 23.0 atom%. The Knoop hardness is Hk 180.

[Comparative Example 1]

The plating was performed in the same manner as in Example 1 except that the citric acid concentration was set to 0.143 mol/dm ³ and the ammonia concentration was set to 0.46 mol/dm ³ , and the obtained plating film was subjected to XRD, TEM, and THEED analysis. The XRD curve is shown in Fig. 1, and the TEM photograph and the THEED graph are shown in Figs. 17-18. It was confirmed that there is a broad peak having a non-fixed peak half-value width of 1 degree or more in the vicinity of 2θ=40 degrees of the XRD curve. Further, in the TEM photograph, an irregular structure unique to the amorphous shape was confirmed, but a regular structure such as a crystal grain boundary and a crystal grain was not confirmed. Furthermore, the hollow ring unique to the amorphous shape can be confirmed in the THEED chart. From this result, it was found that the obtained plating film was a homogeneous amorphous structure having no fine crystals. Further, composition analysis, Knoop hardness and specific resistance of the obtained plating film were measured. The detected content ratio: the metal element portion was 15.2 atom% of gold, the nickel was 67.5 atom%, and the non-metal element portion: carbon was 17.3 atom%. The Knoop hardness is Hk 435; the specific resistance is 251 μΩ ‧ cm.

[Comparative Example 2]

Use KAu(CN) ₂ 0.04 mol/dm ³ , NiSO ₄ ‧6H ₂ O 0.0085 mol/dm ³ , citric acid ‧H ₂ O 0.5 mol/dm ³ , KOH 0.7 mol/dm ³ and adjust the pH with sulfuric acid A 3.5% electrolytic plating solution was formed into a hard gold plating film (film thickness: 1 μm) on a copper plate having a purity of 99.96% at a current density of 10 mA/cm ² at a temperature of 30 °C. Further, a titanium electrode (mesh) was coated on the anode with platinum, and the plating bath in the plating was slowly stirred.

A hard gold plating film obtained by XRD, TEM, and THEED analysis. The XRD curve is shown in Figure 1. It was confirmed that there was a sharp peak derived from Au (111) in the vicinity of 2θ = 38 degrees of the XRD curve. Further, crystals were also confirmed from the TEM photograph and the THEED map. From this result, it was found that the obtained plating film was a polycrystalline structure having no amorphous phase. Further, from the results calculated from the XRD graph, it was found that the average particle diameter of the crystal was 13 nm. On the other hand, the composition analysis, the Knoop hardness and the specific resistance of the obtained plating film were measured. The detected content ratio: the metal element portion was 96.5 atom% of gold, the nickel was 0.77 atom%, and the non-metal element portion: carbon was 2.7 atom%. The Knoop hardness is Hk 160; the specific resistance is 17 μΩ‧cm.

Further, the sharp peak seen in the vicinity of 2θ = 50° of the XRD curve shown in Fig. 1 is caused by copper of the substrate.

Moreover, it is understood that the Knoop hardness of the non-added hard gold (AFHG), the nickel hard gold (NiHG), and the CoHG which are considered to have high hardness in the gold plating film is still less than Hk 200. The Knoop hardness of the fine crystal-unshaped hybrid gold alloy plating film of 1 has a hardness equivalent to 2 to 3 times higher than that of the Nup.

Fig. 1 is a view showing XRD patterns of the fine crystal-deformed mixed gold alloy plating film obtained in Examples 1, 2, 3, 4, and 5 and the gold alloy plating film obtained in Comparative Examples 1 and 2. Picture.

Fig. 2 is a view showing a TEM photograph (100,000 times) of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 1.

Fig. 3 is a view showing a TEM photograph (1 million times) of the fine crystal-deformed mixed gold alloy plating film obtained in Example 1.

Fig. 4 is a view showing the THEED chart of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 1.

Fig. 5 is a view showing a TEM photograph (500,000 times) of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 2.

Fig. 6 is a view showing a TEM photograph (1 million times) of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 2.

Fig. 7 is a view showing the THEED chart of the fine crystal-deformed mixed gold alloy plating film obtained in Example 2.

Fig. 8 is a view showing a TEM photograph (300,000 times) of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 3.

Fig. 9 is a view showing a TEM photograph (1 million times) of the fine crystal-deformed mixed gold alloy plating film obtained in Example 3.

Fig. 10 is a view showing the THEED chart of the fine crystal-deformed mixed gold alloy plating film obtained in Example 3.

Fig. 11 is a view showing a TEM photograph (200,000 times) of the fine crystal-deformed mixed gold alloy plating film obtained in Example 4.

Fig. 12 is a view showing a TEM photograph (700,000 times) of the fine crystal-non-shaped mixed gold alloy plating film obtained in Example 4.

Fig. 13 is a view showing the THEED chart of the fine crystal-deformed mixed gold alloy plating film obtained in Example 4.

Fig. 14 is a view showing a TEM photograph (400,000 times) of the fine crystal-deformed mixed gold alloy plating film obtained in Example 5.

Fig. 15 is a view showing a TEM photograph (1 million times) of the fine crystal-deformed mixed gold alloy plating film obtained in Example 5.

Fig. 16 is a view showing the THEED chart of the fine crystal-deformed mixed gold alloy plating film obtained in Example 5.

Fig. 17 is a view showing a TEM photograph (1 million times) of the amorphous gold alloy plating film obtained in Comparative Example 1.

Fig. 18 is a view showing the THEED chart of the amorphous gold alloy plating film obtained in Comparative Example 1.

Claims (13)

A plated film is a gold alloy plating film and is formed by mixing a crystalline phase and an amorphous phase; the volume fraction of the crystalline phase is 10 to 90%. The plated film described in claim 1 has a crystal phase having a volume fraction of 15 to 60%. The plated film described in the first aspect of the invention is characterized in that the crystal grain has an average particle diameter of 30 nm or less. The plated film described in the first aspect of the invention is characterized in that the amplitude of the peak half value in the vicinity of 2θ=40 degrees in the X-ray diffraction pattern is 1 degree or more. The plated film according to any one of claims 1 to 4, which has a Knoop hardness of Hk 180 or more. The plated film according to any one of claims 1 to 4, which has a specific resistance of 200 μΩ·cm or less. The plated film according to any one of claims 1 to 4, which has a composition formula: Au _100-xy M _x C _y (wherein Au or M is a main component; M is Ni and/ Or Co; C is carbon; 1 atom% ≦ x ≦ 80 atom%; 1 atom% ≦ y ≦ 30 atom%). The plated film according to any one of claims 1 to 4, which is used as an electrical contact material. An electroplating solution for forming an electroplating solution of a plating film according to any one of claims 1 to 8 and comprising a gold cyanide salt, a nickel salt and/or a cobalt compound. Salt, wrong agent and pH adjuster. The electroplating solution according to claim 9, wherein the intercalating agent is composed of citric acid, tartaric acid, malic acid, picolinic acid, phosphoric acid, aminesulfonic acid and sodium, potassium and ammonium salts thereof. 1 selected in the group Or 2 or more; in addition, the pH adjusting agent is ammonia water or potassium hydroxide. The electrical plating solution according to claim 10, wherein the wrong agent is citric acid; and the pH adjuster is ammonia water. A method for forming a gold alloy plating film, which is formed by using an electroplating liquid as described in any one of claims 9 to 11 on a substrate to be formed from a crystal phase and an amorphous form. A mixed gold alloy coating. An electric/electronic component is obtained by using the plating film as described in any one of the above-mentioned claims.