WO2022267384A1 - Fe-ni-p alloy electroplating solution, electro-deposition method for fe-ni-p alloy coating, and alloy coating - Google Patents

Abstract

Disclosed in the present application are an Fe-Ni-P alloy electroplating solution, an electro-deposition method for an Fe-Ni-P alloy coating, and the alloy coating, which belong to the technical field of electronic manufacturing. The electroplating solution comprises a main salt, a complexing agent and water, wherein the complexing agent comprises a double complexing agent comprising citric acid and nitrilotriacetic acid, or citric acid and a nitrilotriacetate, or a citrate and nitrilotriacetic acid, or a citrate and a nitrilotriacetate; in the double complexing agent, the ratio of the concentration of the nitrilotriacetic acid or the nitrilotriacetate to the concentration of the citric acid or the citrate is 0.5 - 5; and the concentration of the citric acid or the citrate is 0.01-0.5 mol/L, and the concentration of the nitrilotriacetic acid or the nitrilotriacetate is 0.01-0.5 mol/L. The citric acid (citrate) and the nitrilotriacetic acid (nitrilotriacetate) are added to the electroplating solution to serve as a double complexing agent in the present application, such that the electrochemical polarization degree of the electroplating solution can be increased, so that a prepared Fe-Ni-P alloy coating has a lower coercive force, a bright surface and a fine structure, and can be applied to the fields of microelectronics, semiconductor functional devices, etc.

Description

A kind of Fe-Ni-P alloy electroplating solution, the electrodeposition method of Fe-Ni-P alloy coating and alloy coating technical field

The present application relates to the technical field of electronic manufacturing, and in particular to an Fe-Ni-P alloy electroplating solution, an electrodeposition method of an Fe-Ni-P alloy coating, and an alloy coating.

Background technique

Inductance is one of the most basic electronic components, and the power inductors, chokes, filters, etc. composed of it are indispensable and important components of electronic circuits. If the discrete passive components can be integrated through inductors, the size reduction of the final product will be dozens or even hundreds of times of what is usually expected today. Inductive applications require high saturation induction to increase its current handling capability, high resistivity to reduce eddy current losses, and low coercive force to reduce hysteresis losses.

The atomic magnetic moments of Fe (iron), Co (cobalt), and Ni (nickel) are 2.2µB, 1.7µB, and 0.6µB, respectively. Moment is close to that of pure iron. Since the wave functions of the 3d electrons of Fe, Co, and Ni overlap each other, the metals and alloys can be ferromagnetic through direct exchange, and the magnetic permeability after alloying is higher than that of pure metals. , so the soft magnetic alloy is generally based on one or two transition metals Fe, Co, Ni.

technical problem

At present, the existing Fe-Ni, Fe-Co binary and multi-element alloy soft magnetic materials can be obtained by electrodeposition, which is low in cost and high in preparation efficiency, but its resistivity is low. In order to further increase the resistivity of Fe-Ni alloy , usually doped with non-metal element P. In the prior art, the formulations of electroless Fe-Ni-P plating include systems using acetic acid (salt), citric acid (salt), glycine, etc. as complexing agents. However, due to the negative codeposition potential of most Fe-Ni-P alloys, the above-mentioned complexing agents cannot effectively adjust the precipitation potential of each metal ion, resulting in insufficient polarization of the plating solution, severe hydrogen evolution reaction, and the final obtained Fe-Ni-P The coating often has a large coercive force, and the surface of the Fe-Ni-P coating is relatively rough and the stress is large.

technical solution

The technical problem mainly solved by this application is to provide a Fe-Ni-P alloy electroplating solution, an electrodeposition method of Fe-Ni-P alloy coating and an alloy coating, by adding citric acid (salt) and nitrilotriacetic acid to the electroplating solution (Salt) as a double complexing agent can solve the problem of high coercive force of Fe-Ni-P coating.

In order to solve the above-mentioned technical problems, the first technical scheme that the application adopts is to provide a kind of Fe-Ni-P alloy electroplating solution, comprise main salt, complexing agent and water, complexing agent comprises double complexing agent, double complexing agent Including citric acid and nitrilotriacetic acid, or citric acid and nitrilotriacetic acid salt, or citrate and nitrilotriacetic acid, or citrate and nitrilotriacetic acid salt; of double complexing agents, nitrilotriacetic acid or nitrilotriacetic acid The ratio of the concentration of acetate to the concentration of citric acid or citrate is 0.5~5; wherein, the concentration of citric acid or citrate is 0.01~0.5mol/L, and the concentration of nitrilotriacetic acid or nitrilotriacetate 0.01~0.5mol/L.

Wherein, the electroplating solution also includes rare earth elements; wherein, the rare earth elements include rare earth salts or rare earth oxides, and the concentration of the rare earth salts or rare earth oxides is 0.25~0.4g/L; the rare earth elements are La, Ce, Pr, Nd, Pm, One or two of Sm, Eu, Gd and Tb.

Among them, the main salt includes ferrous salt, nickel salt and hypophosphite; wherein, the concentration of ferrous salt is 0.01~0.5mol/L, the concentration of nickel salt is 0.01~0.5mol/L, and the concentration of hypophosphite 0.01~0.3mol/L.

Wherein, the ferrous salt includes FeSO ₄ and/or FeCl ₂ , the nickel salt includes one or both of NiSO ₄ , Ni (NH ₂ SO ₃ ) ₂ and NiCl ₂ , and the hypophosphite includes NaH ₂ PO ₂ .

Wherein, the electroplating solution further includes antioxidant, brightener and wetting agent; wherein, the concentration of antioxidant is 0.01~5g/L, the concentration of brightener is 0.01~5g/L, and the concentration of wetting agent is 0.01~5g/L. L; wherein, the antioxidant includes ascorbic acid, the brightener includes sodium saccharin or butynediol, and the wetting agent includes sodium lauryl sulfate.

In order to solve the above-mentioned technical problems, the second technical solution adopted by the present application is to provide a method for electrodeposition of Fe-Ni-P alloy coating, comprising: obtaining Fe-Ni-P alloy electroplating solution, the electroplating solution includes main salt, complexing complexing agent including double complexing agent, double complexing agent including citric acid and nitrilotriacetic acid, or citric acid and nitrilotriacetic acid salt, or citrate and nitrilotriacetic acid, or citrate and ammonia Triacetate; in the double complexing agent, the ratio of the concentration of nitrilotriacetic acid or nitrilotriacetate to the concentration of citric acid or citrate is 0.5~5; wherein the concentration of citric acid or citrate is 0.01 ~0.5mol/L, the concentration of nitrilotriacetic acid or nitrilotriacetic acid salt is 0.01~0.5mol/L; obtain the substrate that has been surface treated; immerse the substrate in the electroplating solution, under constant voltage or constant current condition Electroplating is carried out to deposit an alloy coating on the substrate.

Wherein, the substrate includes a block or film of metal material, a PCB circuit board, and a silicon wafer sputtered with a thin metal layer.

Among them, the content of each element in the Fe-Ni-P alloy coating is adjusted by changing the content of the main salt in the electroplating solution, the content of the complexing agent and any one or several of the process parameters in the electrodeposition process; wherein, the process Parameters include current density, voltage, pH of the plating solution, and temperature of the plating solution.

Among them, the voltage under the constant voltage control condition is 0.7-4.0V, the current density under the constant current condition is 2.0~9.0A/dm ² , the pH value of the electroplating solution is controlled at 2~5, and the temperature of the electroplating solution is controlled at 45 ~60°C.

In order to solve the above-mentioned technical problems, the third technical solution adopted by the present application is to provide a Fe-Ni-P alloy coating, which is made by the above-mentioned electrodeposition method, and the alloy coating includes Fe, Ni and P ; Wherein, the weight percentage content of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, and the rest is P; or, the alloy coating includes Fe, Ni, P and rare earth elements; Among them, the weight percentage content of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, rare earth element >0~2%, and the rest is P.

Beneficial effect

The beneficial effects of the application are: different from the prior art, the application provides a Fe-Ni-P alloy electroplating solution, an electrodeposition method of the Fe-Ni-P alloy coating and an alloy coating, by adding citric acid to the electroplating solution (salt) and nitrilotriacetic acid (salt) as a double complexing agent, using the double complexing agent and metal ions to form more stable complex ions that can exist in the solution, can adjust the precipitation potential of each metal ion in the electroplating solution, The degree of electrochemical polarization of the plating solution is greatly increased, so that the prepared coating has a low degree of disorder and fewer internal structural defects, thereby reducing the coercive force of the Fe-Ni-P alloy coating, and obtaining a coating with a bright surface and a fine structure.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without creative effort.

Fig. 1 is the schematic flow sheet of an embodiment of the electrodeposition method of Fe-Ni-P alloy coating of the present application;

Fig. 2 is the surface topography figure of coating in the embodiment 1～5 of the present application and comparative example 1;

Fig. 3 is the component analysis result figure of coating in the embodiment 1～5 of the present application and comparative example 1;

Fig. 4 is the hysteresis loop schematic diagram of coating in embodiment 3 of the present application;

Fig. 5 is the comparative schematic diagram of the hysteresis loop of the coating in Example 6 of the present application and the hysteresis loop of the coating in Comparative Example 2;

FIG. 6 is a schematic diagram comparing the hysteresis loop of the coating in Example 6 of the present application with the hysteresis loop of the coating in Comparative Example 3. FIG.

Embodiments of the present invention

The following will clearly and completely describe the technical solutions in the embodiments of the application with reference to the drawings in the embodiments of the application. Apparently, the described embodiments are only some of the embodiments of the application, not all of them. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "said" and "the" used in the embodiments of this application and the appended claims are also intended to include plural forms, unless the above clearly indicates otherwise, "multiple "Generally includes at least two, but does not exclude the inclusion of at least one.

It should be understood that the term "and/or" used herein is only an association relationship describing associated objects, which means that there may be three relationships, for example, A and/or B, which may mean that A exists alone, and A and B exist simultaneously. B, there are three situations of B alone. In addition, the character "/" in this article generally indicates that the contextual objects are an "or" relationship.

It should be understood that the terms "comprising", "comprising", or any other variation thereof as used herein are intended to cover a non-exclusive inclusion such that a process, method, article, or apparatus comprising a set of elements includes not only those elements, but also includes Other elements not expressly listed, or elements inherent in the process, method, article, or apparatus are also included. Without further limitations, an element defined by the statement "comprising..." does not exclude the presence of additional same elements in the process, method, article or device comprising said element.

Inductance is one of the most basic electronic components, and the power inductors, chokes, filters, etc. composed of it are indispensable and important components of electronic circuits. If the discrete passive components can be integrated through inductors, the size reduction of the final product will be dozens or even hundreds of times of what is usually expected today. Inductive applications require high saturation induction to increase its current handling capability, high resistivity to reduce eddy current losses, and low coercive force to reduce hysteresis losses.

The atomic magnetic moments of Fe, Co, and Ni are 2.2µB, 1.7µB, and 0.6µB, respectively. In the composition range with high iron content, the atomic magnetic moments of Fe-Co and Fe-Ni alloys are close to those of pure iron. Since the wave functions of the 3d electrons of Fe, Co, and Ni overlap each other, the metals and alloys can be ferromagnetic through direct exchange, and the magnetic permeability after alloying is higher than that of pure metals. , so the soft magnetic alloy is generally based on one or two transition metals Fe, Co, Ni.

At present, the existing Fe-Ni, Fe-Co binary and multi-element alloy soft magnetic materials can be obtained by electrodeposition, which is low in cost and high in preparation efficiency, but its resistivity is low. In order to further increase the resistivity of Fe-Ni alloy , usually doped with non-metal element P. In the prior art, the formulations of electroless Fe-Ni-P plating include systems using acetic acid (salt), citric acid (salt), glycine, etc. as complexing agents. However, due to the negative codeposition potential of most Fe-Ni-P alloys, the above-mentioned complexing agents cannot effectively adjust the precipitation potential of each metal ion, resulting in insufficient polarization of the plating solution, severe hydrogen evolution reaction, and the final obtained Fe-Ni-P The coating often has a large coercive force, and the surface of the Fe-Ni-P coating is relatively rough and the stress is large.

Based on the above situation, the application provides a Fe-Ni-P alloy electroplating solution, an electrodeposition method of Fe-Ni-P alloy coating and an alloy coating, by adding citric acid (salt) and nitrilotriacetic acid in the electroplating solution as bis The complexing agent can solve the problem of high coercive force of Fe-Ni-P coating.

In this application, by adding citric acid (salt) and nitrilotriacetic acid (salt) into the electroplating solution as a double complexing agent, the double complexing agent and metal ions form more stable complexed ions that can exist in the solution, and adjust the electroplating process. The precipitation potential of each metal ion in the solution can greatly increase the electrochemical polarization degree of the plating solution, so that the prepared coating has a lower degree of disorder and fewer internal structural defects, thereby reducing the coercive force of the Fe-Ni-P alloy coating , to obtain a bright surface and a fine-grained coating.

The present application will be described in detail below in conjunction with the accompanying drawings and embodiments.

The Fe-Ni-P alloy electroplating solution provided by the application includes main salt, complexing agent and water, the complexing agent includes double complexing agent, and double complexing agent includes citric acid (C ₆ H ₈ O ₇ , Citric Acid , CA) and nitrilotriacetic acid (N(CH ₂ COOH) ₃ , Nitrilo triacetic acid, NTA), or citric acid and nitrilotriacetic acid, or citrate and nitrilotriacetic acid, or citrate and nitrilotriethyl salt; in the double complexing agent, the ratio of the concentration of nitrilotriacetic acid or nitrilotriacetic acid salt to the concentration of citric acid or citrate is 0.5~5; wherein, the concentration of citric acid or citrate is 0.01~0.5 mol/L, the concentration of nitrilotriacetic acid or nitrilotriacetic acid salt is 0.01~0.5mol/L.

Among them, the citrate includes sodium citrate (C ₆ H ₅ Na ₃ O ₇ ).

Specifically, when the ratio of the concentration of nitrilotriacetic acid or nitrilotriacetate to the concentration of citric acid or citrate is 0.5-5, the double complexing agent can perform better complexation with metal ions. And the higher the concentration of nitrilotriacetic acid or nitrilotriacetic acid salt, the higher the content of Fe in the final alloy coating and the higher the saturation magnetic induction.

In this embodiment, the main salt includes ferrous salt, nickel salt and hypophosphite; wherein, the concentration of ferrous salt is 0.01-0.5mol/L, the concentration of nickel salt is 0.01-0.5mol/L, and the concentration of hypophosphite The concentration of salt is 0.01~0.3mol/L.

Wherein, ferrous salt includes FeSO ₄ (ferrous sulfate) and/or FeCl ₂ (ferrous chloride), nickel salt includes NiSO ₄ (nickel sulfate), Ni (NH ₂ SO ₃ ) ₂ (nickel sulfamate) and One or both of NiCl ₂ (nickel chloride), and hypophosphites include NaH ₂ PO ₂ (sodium hypophosphite).

Specifically, doping the non-metallic element P on the basis of the Fe-Ni alloy can increase the resistivity of the alloy coating. Since the co-deposition potential of Fe-Ni-P alloy is relatively negative, citric acid (salt) and nitrilotriacetic acid are added as double complexing agents in the electroplating solution, and the double complexing agent can be used to form complex ions with metal ions. The ions are more stable than the previous metal ions, which can make it more difficult for the metal to deposit out of the solution, thereby adjusting the precipitation potential of each metal ion in the electroplating solution, increasing the electrochemical polarization of the plating solution, and making the generated tissue More delicate to further generate Fe-Ni-P alloy coatings with lower disorder and fewer internal structural defects, and low coercive force usually benefits from lower disorder of the coating and fewer internal structural defects.

In this embodiment, the electroplating solution further includes an antioxidant, a brightener and a wetting agent; wherein, the concentration of the antioxidant is 0.01 to 5 g/L, the concentration of the brightener is 0.01 to 5 g/L, and the concentration of the wetting agent is 0.01 ~5g/L; Among them, antioxidants include ascorbic acid, brighteners include sodium saccharin or butynediol, and wetting agents include sodium lauryl sulfate.

Wherein, the electroplating solution also includes H ₃ BO ₃ (boric acid), wherein the concentration of H ₃ BO ₃ is 0.25˜1 mol/L. Specifically, boric acid, as a buffer, can suppress the change of the pH value of the electroplating solution during electroplating.

In other embodiments, the electroplating solution also includes rare earth elements (RE); wherein, the rare earth elements include rare earth salts or rare earth oxides, and the concentration of the rare earth salts or rare earth oxides is 0.25~0.4g/L; the rare earth elements are La (lanthanum ), Ce (cerium), Pr (praseodymium), Nd (neodymium), Pm (promethium), Sm (samarium), Eu (uranium), Gd (gadolinium) and Tb (terbium).

Specifically, adding an appropriate amount of rare earth elements can increase the polarization of the plating solution.

Different from the prior art, this embodiment adds citric acid (salt) and nitrilotriacetic acid (salt) as double complexing agents to the electroplating solution, and utilizes double complexing agents and metal ions to form more stable metal ions that can exist in the solution. complex ions, which can adjust the precipitation potential of each metal ion in the electroplating solution, greatly increase the degree of electrochemical polarization of the plating solution, make the prepared coating less disordered and have fewer internal structural defects, thereby reducing the Fe-Ni- The coercive force of the P alloy coating can be used to obtain a coating with a bright surface and a fine structure. Furthermore, because the electroplating solution system in this embodiment is simple, high in stability, low in the concentration of each component, and has the advantages of low cost and easy promotion, it can be widely used in the fields of microelectronics and semiconductor functional devices.

Correspondingly, the present application provides an electrodeposition method of Fe-Ni-P alloy coating.

Please refer to FIG. 1 . FIG. 1 is a schematic flowchart of an embodiment of an electrodeposition method of Fe—Ni—P alloy coating in the present application. As shown in Figure 1, in this embodiment, the method includes:

S11: Obtain Fe-Ni-P alloy electroplating solution, electroplating solution includes main salt, complexing agent and water, complexing agent includes double complexing agent, double complexing agent includes citric acid and nitrilotriacetic acid, or citric acid and ammonia triacetate, or citrate and nitrilotriacetic acid, or citrate and nitrilotriacetate; the concentration of nitrilotriacetic acid or nitrilotriacetate in the double complexing agent was the same as that of citric acid or citrate The concentration ratio is 0.5~5; wherein, the concentration of citric acid or citrate is 0.01~0.5mol/L, and the concentration of nitrilotriacetic acid or nitrilotriacetic acid salt is 0.01~0.5mol/L.

In this embodiment, firstly, the concentrations of the main salt, complexing agent and additives in the electroplating solution are selected. Specifically, the main salt includes ferrous salt, nickel salt and hypophosphite; wherein, the concentration of ferrous salt is 0.01~0.5mol/L, the concentration of nickel salt is 0.01~0.5mol/L, and the concentration of hypophosphite The concentration is 0.01~0.3mol/L; wherein, the ferrous salt includes FeSO ₄ and/or FeCl ₂ , the nickel salt includes one or both of NiSO ₄ , Ni (NH ₂ SO ₃ ) ₂ and NiCl ₂ , and the subferrous Phosphates include NaH ₂ PO ₂ . The selection and parameters of the double complexing agent are as described above. Additives include antioxidants, brighteners and wetting agents; wherein, the concentration of antioxidants is 0.01~5g/L, the concentration of brighteners is 0.01~5g/L, and the concentration of wetting agents is 0.01~5g/L; among them, Antioxidants include ascorbic acid, brighteners include sodium saccharin or butynediol, and humectants include sodium lauryl sulfate.

In this embodiment, boric acid is first dissolved in deionized water at 85° C., stirred and dissolved, and sodium hypophosphite, complexing agent, additives, etc. are added in sequence. Use NaOH (sodium hydroxide) and HCl (hydrochloric acid) to adjust the pH value of the resulting mixed solution to 2~5, then add ferrous salt and nickel salt; use HCl to fine-tune the pH, then pour the mixed solution into a volumetric flask To obtain Fe-Ni-P alloy plating solution.

Among them, NaOH cannot be used to adjust the pH after adding ferrous salt and nickel salt to prevent precipitation.

Further, adjust the temperature of the electroplating solution, and control the temperature of the electroplating solution to be 45-60°C.

In other embodiments, boric acid is first dissolved in deionized water at 85° C., stirred and dissolved, and then rare earth elements, sodium hypophosphite, complexing agents, additives, etc. are added in sequence. Use NaOH (sodium hydroxide) and HCl (hydrochloric acid) to adjust the pH value of the resulting mixed solution to 2~5, then add ferrous salt and nickel salt; use HCl to fine-tune the pH, then pour the mixed solution into a volumetric flask To obtain Fe-Ni-P-RE alloy electroplating solution.

S12: Acquiring a surface-treated substrate.

In this embodiment, the base material includes a block or film of a metal material, a PCB circuit board, and a silicon wafer sputtered with a thin metal layer.

Among them, the metals include copper (Cu), titanium (Ti), aluminum (Al), tantalum (Ta), and titanium-tungsten alloy (Ti-W).

Before electrodepositing the alloy coating on the substrate, the surface treatment of the substrate can remove possible dust, grease, oxides, etc. Among them, reducing the washing of the substrate can remove grease; carrying out pickling on the substrate can remove oxides.

Specifically, the steps of alkaline cleaning of the substrate are: cleaning the surface of the substrate with deionized water to remove dust; and then placing the substrate in a 50°C degreasing alkaline solution to clean the grease on the surface of the substrate. Among them, the degreasing lye is a mixture of NaOH and Na ₃ PO ₄ (sodium phosphate), the concentration of NaOH is 10g/L, and the concentration of Na ₃ PO ₄ is 20g/L; Dry and set aside.

The steps of pickling the substrate are: cleaning the surface of the substrate with deionized water to remove dust; then placing the substrate in the pickling solution to remove the oxide layer on the surface of the substrate to achieve the purpose of surface activation. Among them, the pickling solution is 5% HCl or dilute H ₂ SO ₄ (sulfuric acid); rinse with deionized water after pickling, and dry it for later use.

S13: immersing the substrate in an electroplating solution, and performing electroplating under constant voltage or constant current conditions, so as to deposit an alloy coating on the substrate.

In this embodiment, before electroplating, process parameters of electrodeposition need to be determined. Wherein, the process parameters include current density, voltage, pH value of the electroplating solution and temperature of the electroplating solution.

For example, choose a certain current density and calculate the applied current based on the surface area to be plated. If there are parts that do not need electroplating, they can be covered with photoresist, resin or other insulating treatments.

Further, the cathode and anode materials required for electroplating are selected. Wherein, the cathode material is the substrate, the anode material is Fe-Ni alloy, and the content of Fe in the Fe-Ni alloy is 70wt.%.

In other embodiments, the anode material can also be pure iron balls and pure nickel balls, wherein the volume of pure iron balls accounts for 60-70%, which is not limited in this application. Specifically, when the anode materials are pure iron balls and pure nickel balls, it is necessary to put the anode balls into the titanium basket.

Further, the substrate is immersed in the electroplating solution, and electroplating is performed under constant voltage or constant current conditions, and the agitation form of cathode swing and circulating spray of the plating solution is used during the electroplating process.

In this embodiment, by changing any one or more of the content of the main salt in the electroplating solution, the content of the complexing agent, and the process parameters in the electrodeposition process, the content of each element in the Fe-Ni-P alloy coating can be adjusted. The content is adjusted to obtain alloy coatings with different components. Specifically, adjusting the ratio of Fe, Ni, P, and RE components in the coating can achieve controllable adjustment of the thermal expansion coefficient, magnetic properties, and electrical properties of the thin film material.

Wherein, the voltage under the constant voltage control condition is 0.7-4.0V, and the current density under the constant current control condition is 2.0-9.0A/dm ² .

Wherein, the control electroplating time is 5-60min.

Further, after the electroplating time is over, the power supply is stopped immediately, the stirring is stopped, and the plating layer and the substrate are taken out. Since the electroplating solution is acidic, it is necessary to repeatedly rinse and transfer the plating layer with deionized water to remove the residual plating solution on the surface of the plating layer. After cleaning, dry the surface of the plating layer with compressed air.

Different from the prior art, this embodiment provides a plating solution system with citric acid (salt) and nitrilotriacetic acid (salt) as double complexing agents, which has a more obvious polarization effect, so that the disorder of the prepared coating can be lower And there are few internal structural defects, thereby reducing the coercive force of the Fe-Ni-P alloy coating, and obtaining a coating with a bright surface and a fine structure. Furthermore, because the electroplating solution system in this embodiment is simple, high in stability, low in the concentration of each component, and has the advantages of low cost and easy promotion, it can be widely used in the fields of microelectronics and semiconductor functional devices. In addition, by changing any one or several items of the content of the main salt in the electroplating solution, the content of the complexing agent, and the process parameters in the electrodeposition process, alloy coatings with different components can also be obtained to expand the application range of materials.

Correspondingly, the present application provides an Fe-Ni-P alloy coating, which is made by the above-mentioned electrodeposition method.

In this embodiment, the Fe-Ni-P alloy coating includes Fe, Ni and P; wherein, the weight percentage content of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, The rest is P; or, the alloy coating includes Fe, Ni, P and rare earth elements; wherein, the weight percentage content of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, rare earth Elements>0~2%, the rest is P.

Specifically, the higher the iron content in the Fe-Ni-P alloy coating, the higher its saturation magnetic induction. The high resistivity is obtained by non-metallic elements, generally doped with 5~15% non-metallic element P, which can increase the resistivity by about 10 times.

In this embodiment, the iron content of the alloy coating is relatively high, so the coating has a high saturation magnetic induction; due to the doping of a part of P, it also has a high resistivity.

More importantly, because the plating solution system with citric acid (salt) and nitrilotriacetic acid as double complexing agents with more obvious polarization effect is used in electroplating, the coercive force of the prepared alloy coating is low.

Different from the prior art, this embodiment provides a plating solution system with citric acid (salt) and nitrilotriacetic acid (salt) as double complexing agents, which has a more obvious polarization effect, so that the prepared alloy coating can be highly saturated Magnetic induction intensity, high resistivity and low coercive force are required for magnetic core materials, and its comprehensive performance is excellent, which can be applied to related electroplated magnetic film applications such as advanced integrated circuit packaging and printed circuit board manufacturing.

In order to facilitate the understanding of the embodiments of the present application, the present application provides the following non-limiting examples to further describe the present application in detail.

Example 1

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, N(CH ₂ COOH) ₃ is 0.01mol/L, Ascorbic acid is 5g/L, sodium saccharin is 2g/L, sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH value of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10min.

Example 2

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, N(CH ₂ COOH) ₃ is 0.05mol/L, Ascorbic acid is 5g/L, sodium saccharin is 2g/L, sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10 min.

Example 3

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, N(CH ₂ COOH) ₃ is 0.10mol/L, Ascorbic acid is 5g/L, sodium saccharin is 2g/L, sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH value of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10min.

Example 4

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, N(CH ₂ COOH) ₃ is 0.15mol/L, Ascorbic acid is 5g/L, sodium saccharin is 2g/L, sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH value of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10min.

Example 5

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, N(CH ₂ COOH) ₃ is 0.20mol/L, Ascorbic acid is 5g/L, sodium saccharin is 2g/L, sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH value of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10min.

Comparative example 1

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.10mol/L, NiSO ₄ 6H ₂ O is 0.10mol/L, NaH ₂ PO ₂ is 0.20mol/L, Nd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.25mol/L, C ₆ H ₈ O ₇ is 0.05mol/L, ascorbic acid is 5g/L, sodium saccharin is 2g/L, Sodium lauryl sulfate is 1g/L, and the rest is water. The wafer sputtered with the TiW seed layer was surface-treated and placed in the plating tank, using Fe-Ni alloy (Fe70wt.%) as the anode material, adjusting the pH value of the plating solution to 3, and controlling the temperature of the plating solution to 60 °C, the current density is controlled to be 3.0A/dm ² , and the electroplating time is controlled to be 10min.

Observe the surface morphology of the coatings in Examples 1-5 and Comparative Example 1 with an electron microscope, and test the composition of the coatings in Examples 1-5 and Comparative Example 1.

Specifically, please refer to Fig. 2 and Fig. 3, Fig. 2 is the surface topography figure of coating in the embodiment 1 ~ 5 of the present application and comparative example 1, Fig. 3 is the coating in embodiment 1 ~ 5 of the present application and comparative example 1 Composition analysis result graph. It can be seen from Figure 2 and Figure 3 that only the content of nitrilotriacetic acid is changed, and other conditions remain unchanged. When the content of nitrilotriacetic acid increases from 0mol/L to 0.20mol/L, the surface of the coating changes from having defects to no obvious defects. It shows that the brightness of the coating is gradually improved, and the microstructure is more detailed; at the same time, the content of Fe in the alloy coating increases from 12wt.% to 80wt.%, and the content of Ni decreases from 70wt.% to 5wt.%, indicating that the composition of the coating is adjusted by nitrilotriacetic acid The content of Fe can be adjusted within a wide range, and the higher the nitrilotriacetic acid content, the higher the Fe content.

Further, in Example 3, when nitrilotriacetic acid is 0.15mol/L, the coating composition is Fe76.80wt.%, Ni10.85wt.%, P12.35wt.%. Obtain the hysteresis loop of the coating in Example 3. Specifically, please refer to FIG. 4 , which is a schematic diagram of the hysteresis loop of the coating in Example 3 of the present application. As shown in Figure 4, the saturation magnetic induction of the coating is 1.3T, and the coercive force is 0.8Oe, indicating that when the content of Fe is higher, the saturation magnetic induction of the coating is higher, and it also shows that nitrilotriacetic acid is added to the plating solution to form After the double complexing agent, the coercive force of the coating is lower.

Example 6

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.50mol/L, NiSO ₄ 6H ₂ O is 0.50mol/L, NaH ₂ PO ₂ is 0.01mol/L, Gd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.50mol/L, C ₆ H ₈ O ₇ is 0.20mol/L, N(CH ₂ COOH) ₃ is 0.20mol/L, Ascorbic acid is 5g/L, sodium saccharin is 5g/L, sodium lauryl sulfate is 5g/L, and the rest is water. Put the wafer sputtered with Ti/Cu seed layer into the plating tank after surface treatment, use pure iron balls and pure nickel balls (pure iron balls account for 60~70% of the volume) as anode materials, adjust the plating solution The pH value is 5, the temperature of the electroplating solution is controlled to be 45° C., the current density is controlled to be 6.0 A/dm ² , and the electroplating time is controlled to be 20 minutes.

Comparative example 2

Fe-Ni-P alloy electroplating solution is obtained, wherein, the composition and concentration of the electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.50 mol/L, NiSO ₄ 6H ₂ O is 0.50 mol/L, H ₃ BO ₃ is 0.50mol/L, ascorbic acid 5g/L, sodium saccharin 5g/L, sodium lauryl sulfate 5g/L, and the rest is water. Put the wafer sputtered with Ti/Cu seed layer into the plating tank after surface treatment, use pure iron balls and pure nickel balls (pure iron balls account for 60~70% of the volume) as anode materials, adjust the plating solution The pH value is 5, the temperature of the electroplating solution is controlled to be 45° C., the current density is controlled to be 6.0 A/dm ² , and the electroplating time is controlled to be 20 minutes.

Comparative example 3

Obtain Fe-Ni-P alloy electroplating solution, wherein, the composition and concentration of electroplating solution are as follows: FeSO ₄ 7H ₂ O is 0.50mol/L, NiSO ₄ 6H ₂ O is 0.50mol/L, NaH ₂ PO ₂ is 0.01mol/L, Gd ₂ O ₃ is 0.25g/L, H ₃ BO ₃ is 0.50mol/L, C ₆ H ₈ O ₇ is 0.20mol/L, ascorbic acid is 5g/L, sodium saccharin is 5g/L, Sodium lauryl sulfate is 5g/L, and the rest is water. Put the wafer sputtered with Ti/Cu seed layer into the plating tank after surface treatment, use pure iron balls and pure nickel balls (pure iron balls account for 60~70% of the volume) as anode materials, adjust the plating solution The pH value is 5, the temperature of the electroplating solution is controlled to be 45° C., the current density is controlled to be 6.0 A/dm ² , and the electroplating time is controlled to be 20 minutes.

Test the composition of coating in embodiment 6 and comparative example 2,3, wherein, the composition of coating in embodiment 6 is Fe 80.14wt.%, Ni 9.36wt.%, P 10.30wt.%, Gd 0.20wt.%; The composition of the coating in Example 2 is Fe 50wt.%, Ni 50wt.%; the composition of the coating in Comparative Example 3 is Fe 33wt.%, Ni 54wt.%, P 11wt.%, Gd 2wt.%.

The hysteresis loops of the coatings in Example 6 and Comparative Examples 2 and 3 were obtained and comparatively analyzed. Specifically, please refer to Fig. 5 and Fig. 6. Fig. 5 is a comparative schematic diagram of the hysteresis loop of the coating in Example 6 of the present application and the hysteresis loop of the coating in Comparative Example 2. Fig. 6 is a schematic diagram of the hysteresis loop in Example 6 of the present application. The comparison schematic diagram of the hysteresis loop of the coating and the hysteresis loop of the coating in Comparative Example 3.

As shown in Figure 5, the saturation magnetic induction of the coating in Example 6 is 1.5T, and the coercive force is 0.6Oe. When the solution is doped with sodium hypophosphite, adding citric acid and nitrilotriacetic acid as a double complexing agent can greatly increase the polarization of the plating solution, and obtain a higher saturation while obtaining a Fe-Ni-P co-deposited film. Magnetic induction, and reduced coercive force. As shown in Figure 6, the saturation magnetic induction of the coating in Comparative Example 3 is 1.1T, and the coercive force is 7Oe, showing that when doping sodium hypophosphite on the basis of the iron-nickel plating solution, only citric acid is added as a complexing agent, Even if rare earth elements are added, the polarization of the plating solution cannot be greatly increased, and the content of Fe in the coating is also low, resulting in low saturation magnetic induction and high coercive force of the obtained Fe-Ni-P co-deposited film.

Further, observe the surface appearance of the coating in Example 6 and Comparative Examples 2 and 3 under a microscope, and find that the surface of the coating in Example 6 and Comparative Example 2 is bright without obvious defects, while the surface of the coating in Comparative Example 3 is whitish And there are cracks, indicating that when doping sodium hypophosphite on the basis of iron-nickel plating solution, adding citric acid and nitrilotriacetic acid as double complexing agents can make the prepared coating have low disorder and internal structural defects.

Different from the prior art, this application adds citric acid (salt) and nitrilotriacetic acid (salt) as double complexing agents to the electroplating solution, and utilizes double complexing agents and metal ions to form more stable metal ions that can exist in the solution. Complex ions can adjust the precipitation potential of each metal ion in the electroplating solution, greatly increase the electrochemical polarization of the plating solution, make the prepared coating less disordered and have fewer internal structural defects, thereby reducing Fe-Ni-P The coercive force of the alloy coating can be used to obtain a coating with a bright surface and a fine structure. Furthermore, because the electroplating solution system in this embodiment is simple, high in stability, low in the concentration of each component, and has the advantages of low cost and easy promotion, it can be widely used in the fields of microelectronics and semiconductor functional devices.

The above is only the implementation of the application, and does not limit the patent scope of the application. Any equivalent structure or equivalent process conversion made by using the specification and drawings of the application, or directly or indirectly used in other related technologies fields, are all included in the scope of patent protection of this application in the same way.

Claims (10)

1. A Fe-Ni-P alloy electroplating solution, comprising main salt, complexing agent and water, is characterized in that, described complexing agent comprises double complexing agent, and described double complexing agent comprises citric acid and nitrilotriacetic acid, Or the citric acid and the nitrilotriacetic acid salt, or the citrate and the nitrilotriacetic acid, or the citrate and the nitrilotriacetic acid salt; in the double complexing agent, the nitrilotriacetic acid salt The ratio of the concentration of acetic acid or the nitrilotriacetate to the concentration of the citric acid or the citrate is 0.5-5; wherein, the concentration of the citric acid or the citrate is 0.01-0.5mol/L , the concentration of the nitrilotriacetic acid or the nitrilotriacetic acid salt is 0.01-0.5mol/L.
2. Fe-Ni-P alloy electroplating solution according to claim 1, is characterized in that, described electroplating solution also comprises rare earth element; Wherein, described rare earth element comprises rare earth salt or rare earth oxide, and described rare earth salt or rare earth oxide The concentration of the substance is 0.25~0.4g/L; the rare earth element is one or two of La, Ce, Pr, Nd, Pm, Sm, Eu, Gd and Tb.
3. Fe-Ni-P alloy electroplating solution according to claim 1 or 2, is characterized in that, described main salt comprises ferrous salt, nickel salt and hypophosphite; Wherein, the concentration of described ferrous salt is 0.01 ~0.5mol/L, the concentration of the nickel salt is 0.01~0.5mol/L, and the concentration of the hypophosphite is 0.01~0.3mol/L.
4. The Fe-Ni-P alloy electroplating solution according to claim 3, wherein the ferrous salt includes FeSO ₄ and/or FeCl ₂ , and the nickel salt includes NiSO ₄ , Ni (NH ₂ SO ₃ ) ₂ and one or both of NiCl ₂ , the hypophosphite includes NaH ₂ PO ₂ .
5. Fe-Ni-P alloy electroplating solution according to claim 4, is characterized in that, described electroplating solution further comprises antioxidant, brightener and wetting agent; Wherein, the concentration of described antioxidant is 0.01～5g/L , the concentration of the brightener is 0.01 ~ 5g/L, the concentration of the wetting agent is 0.01 ~ 5g/L; wherein, the antioxidant includes ascorbic acid, the brightener includes sodium saccharin or butynediol, The wetting agent includes sodium lauryl sulfate.
6. A kind of electrodeposition method of Fe-Ni-P alloy coating, is characterized in that, comprises:

   Obtain Fe-Ni-P alloy electroplating solution, said electroplating solution comprises main salt, complexing agent and water, said complexing agent comprises double complexing agent, and said double complexing agent comprises citric acid and nitrilotriacetic acid, or The citric acid and the nitrilotriacetic acid salt, or the citrate and the nitrilotriacetic acid, or the citrate and the nitrilotriacetic acid salt; in the double complexing agent, the nitrilotriacetic acid Or the ratio of the concentration of the nitrilotriacetate to the concentration of the citric acid or the citrate is 0.5~5; wherein, the concentration of the citric acid or the citrate is 0.01~0.5mol/L, The concentration of the nitrilotriacetic acid or the nitrilotriacetic acid salt is 0.01 ~ 0.5mol/L;

   Obtain the surface-treated substrate;

   The substrate is immersed in the electroplating solution, and electroplating is performed under constant voltage or constant current conditions, so as to deposit the alloy coating on the substrate.
7. The electrodeposition method of Fe-Ni-P alloy coating according to claim 6, characterized in that, the substrate comprises a block or film of metal material, a PCB circuit board, and a silicon chip sputtered with a thin metal layer.
8. The electrodeposition method of the Fe-Ni-P alloy coating according to claim 7, wherein the content of each element in the Fe-Ni-P alloy coating is changed by changing the content of the main salt in the electroplating solution , the content of the complexing agent and any one or more of the process parameters in the electrodeposition process are adjusted; wherein the process parameters include the current density, the voltage, the pH value of the electroplating solution, and The temperature of the electroplating solution.
9. The electrodeposition method of Fe-Ni-P alloy coating according to claim 8, is characterized in that, the voltage under control described constant voltage condition is 0.7-4.0V, the current density under control described constant current condition is 2.0 ~9.0A/dm ² , the pH of the electroplating solution is controlled to be 2~5, and the temperature of the electroplating solution is controlled to be 45~60°C.
10. A kind of Fe-Ni-P alloy coating, it is characterized in that, described Fe-Ni-P alloy coating is made by the electrodeposition method described in any one of claim 6～9, and described alloy coating comprises Fe, Ni and P; Among them, the weight percentage content of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, and the rest is P;

    Or, the alloy coating includes Fe, Ni, P and rare earth elements; wherein, the weight percentage of each element is: Fe 10~85%, Ni 5~70%, Fe+Ni=70~95%, rare earth elements> 0~2%, the rest is P.