阅读说明：本技术 一种在金属导电图形上电镀Pt的方法 (Method for electroplating Pt on metal conductive pattern ) 是由 任超 马明 陈冬冬 李蒋 李伟民 邵龑 杨春雷 于 2021-08-12 设计创作，主要内容包括：本发明公开了一种在金属导电图形上电镀Pt的方法,其包括：提供具有金属导电图形的基底,对所述基底进行表面亲水性处理；配制用于电镀Pt的电镀液,于所述电镀液中在所述金属导电图形上电镀形成Pt镀层；对形成Pt镀层后的基底依次进行清洗和干燥处理。本发明实施例提供的方法,在电镀Pt前对具有金属导电图形的基底首先进行表面亲水性处理,由此提升了Pt镀层的附着力,从而获得的金属Pt镀层稳定均一、图案清晰、有明显的金属光泽,是一种可操作性强的电镀方法。(The invention discloses a method for electroplating Pt on a metal conductive pattern, which comprises the following steps: providing a substrate with a metal conductive pattern, and carrying out surface hydrophilic treatment on the substrate; preparing an electroplating solution for electroplating Pt, and electroplating on the metal conductive pattern in the electroplating solution to form a Pt coating; and sequentially cleaning and drying the substrate with the Pt coating. According to the method provided by the embodiment of the invention, the substrate with the metal conductive pattern is subjected to surface hydrophilic treatment before Pt is electroplated, so that the adhesive force of the Pt plating layer is improved, and the obtained metal Pt plating layer is stable and uniform, has clear patterns and obvious metal luster, and is an electroplating method with strong operability.)

1. A method of electroplating Pt on a metallic conductive pattern, comprising:

providing a substrate with a metal conductive pattern, and carrying out surface hydrophilic treatment on the substrate;

preparing an electroplating solution for electroplating Pt, and electroplating on the metal conductive pattern in the electroplating solution to form a Pt coating;

and sequentially cleaning and drying the substrate with the Pt coating.

2. The method of electroplating Pt on a metallic conductive pattern according to claim 1, wherein the subjecting the substrate to a surface hydrophilic treatment comprises: soaking the substrate in a mixed solution of hydrochloric acid and hydrogen peroxide for 30-60 min; wherein the volume ratio of the hydrochloric acid to the hydrogen peroxide is 1: 1-1: 5.

3. The method of electroplating Pt on a metal conductive pattern according to claim 2, wherein the hydrochloric acid has a concentration of 0.1M to 0.5M, and the hydrogen peroxide has a volume concentration of 10% to 30%.

4. The method of electroplating Pt on a metallic conductive pattern according to claim 1, wherein the subjecting the substrate to a surface hydrophilic treatment comprises: soaking the substrate in a mixed solution of hydrochloric acid and ammonia water for 30-60 min; wherein the volume ratio of the hydrochloric acid to the ammonia water is 1: 1-1: 3.

5. The method of electroplating Pt on a metal conductive pattern according to claim 4, wherein the hydrochloric acid has a concentration of 0.1M to 0.5M, and the ammonia water has a volume concentration of 10% to 30%.

6. A method of electroplating Pt on a metal conductive pattern according to any one of claims 1-5, wherein the electroplating solution is a chloroplatinic acid solution having a concentration of 20mM to 60 mM.

7. The method of claim 6, wherein the step of forming a Pt coating layer on the metal conductive pattern by electroplating in the electroplating solution comprises: and in the electroplating solution, the substrate is used as a working electrode, and a three-electrode electroplating system is adopted to electroplate on the metal conductive pattern to form a Pt coating.

8. The method of electroplating Pt on a metal conductive pattern according to claim 7, wherein in the three-electrode electroplating system, the reference electrode is an Ag/AgCl standard electrode and the counter electrode is a platinum sheet electrode.

9. The method of claim 7, wherein the plating is performed by a three-electrode plating system, wherein the potential scan rate is 0.001V/s to 0.1V/s, the operating voltage is-0.5V to 0.5V, the operating current is 0.2mA to 2mA, and the plating time is 10min to 30 min.

10. The method for electroplating Pt on a metal conductive pattern according to claim 9, wherein the operating voltage is-0.1V, the operating current is 0.6 mA-1 mA, and the electroplating time is 10 min-15 min.

Technical Field

The invention relates to the field of micro-nano processing, in particular to a method for electroplating Pt on a metal conductive pattern.

Background

The micro-nano processing technology refers to the optimized design, processing, assembly, system integration and application technology of millimeter, sub-millimeter, micron and nanometer level elements and parts or systems formed by the elements, relates to the field of wide and multidisciplinary cross fusion, and has the main development direction of micro-nano devices and systems (MEMS and NEMS). Since the traditional "macro" mechanical manufacturing technology can not meet the high-precision manufacturing and assembling processing requirements of the "micro" machines and the "micro" systems, the technology and the method for micro-nano manufacturing must be researched and applied. The micro-nano manufacturing technology is a basic means and an important basis for manufacturing a micro sensor, a micro actuator, a micro structure and a functional micro-nano system. The micro-nano processing technology is an important component of advanced manufacturing, is one of the marks for measuring the high-end manufacturing level of the country, has the characteristics of multidisciplinary intersection and extreme manufacturing elements, and plays a key role in promoting scientific research, promoting industrial development, pulling technical progress, guaranteeing national defense safety and the like.

Platinum (Pt), one of the noble metals, has a melting point of 1772 ℃, a boiling point of 3827 ± 100 ℃, good ductility, thermal and electrical conductivity, and is easy to machine and mold. Therefore, it has a very wide application in all aspects. In the chemical industry, to manufacture advanced chemical vessels, platinum crucibles, electrodes and catalysts to accelerate the rate of chemical reactions. In the automobile industry, the platinum has no substitution effect on the aspects of tail gas treatment and the like, and the consumption amount almost accounts for half of the consumption amount of the platinum industry. In the field of micro-nano processing, platinum also has very important application, such as being used as an electrode of a device and the like. However, the platinum resource is scarce and the price is high, so that the massive use of platinum metal is restricted, and the platinum-plated material is used for replacing a pure platinum product, so that the cost is reduced, and the platinum product has a plurality of excellent performances of the platinum.

The electroplating process is one of the important steps in the field of micro-nano processing, and is a method for paving a layer of metal on a conductor by utilizing the principle of electrolysis. Electroplating is a surface treatment method in which cations of a pre-plated metal in a plating solution are deposited on the surface of a substrate to be plated by electrolysis using the substrate as a cathode in the solution containing the pre-plated metal to form a plated layer. The obtained coating has new characteristics different from the coated substrate. During electroplating, plating metal or other insoluble materials are used as an anode, a workpiece to be plated is used as a cathode, and cations of the plating metal are reduced on the surface of the workpiece to be plated to form a plating layer. There have been reported methods for plating Pt on a metal conductive pattern, in which the Pt plating layer has insufficient adhesion to the conductive pattern, and thus the obtained Pt plating layer has poor uniformity and stability.

Disclosure of Invention

In view of the above, the present invention provides a method for electroplating Pt on a metal conductive pattern, so as to solve the problem in the prior art that the uniformity and stability of a Pt plating layer obtained by electroplating on a conductive pattern are poor.

In order to solve the above problems, the present invention provides a method of electroplating Pt on a metal conductive pattern, comprising:

providing a substrate with a metal conductive pattern, and carrying out surface hydrophilic treatment on the substrate;

preparing an electroplating solution for electroplating Pt, and electroplating on the metal conductive pattern in the electroplating solution to form a Pt coating;

and sequentially cleaning and drying the substrate with the Pt coating.

Specifically, the surface hydrophilic treatment of the substrate comprises: soaking the substrate in a mixed solution of hydrochloric acid and hydrogen peroxide for 30-60 min; wherein the volume ratio of the hydrochloric acid to the hydrogen peroxide is 1: 1-1: 5.

More specifically, the concentration of the hydrochloric acid is 0.1-0.5M, and the volume concentration of the hydrogen peroxide is 10-30%.

Specifically, the surface hydrophilic treatment of the substrate comprises: soaking the substrate in a mixed solution of hydrochloric acid and ammonia water for 30-60 min; wherein the volume ratio of the hydrochloric acid to the ammonia water is 1: 1-1: 3.

More specifically, the concentration of the hydrochloric acid is 0.1-0.5M, and the volume concentration of the ammonia water is 10-30%.

Specifically, the electroplating solution is a chloroplatinic acid solution with the concentration of 20 mM-60 mM.

Specifically, the electroplating of the Pt plating layer on the metal conductive pattern in the electroplating solution includes: and in the electroplating solution, the substrate is used as a working electrode, and a three-electrode electroplating system is adopted to electroplate on the metal conductive pattern to form a Pt coating.

More specifically, in the three-electrode electroplating system, the reference electrode is an Ag/AgCl standard electrode, and the counter electrode is a platinum sheet electrode.

More specifically, when a three-electrode electroplating system is adopted for electroplating, the potential scanning rate is 0.001V/s-0.1V/s, the working voltage is-0.5V, the working current is 0.2 mA-2 mA, and the electroplating time is 10 min-30 min.

More specifically, the working voltage is-0.1V, the working current is 0.6 mA-1 mA, and the electroplating time is 10 min-15 min.

According to the method for electroplating the Pt on the metal conductive pattern, provided by the embodiment of the invention, before the Pt is electroplated, the surface hydrophilic treatment is firstly carried out on the substrate with the metal conductive pattern, so that the adhesive force of the Pt coating and the substrate is improved, and the stability and the uniformity of the metal Pt coating obtained by electroplating are improved.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments of the present invention or in the description of the prior art will be briefly described below, and it is obvious that the drawings described below are only some embodiments of the present invention, and it is obvious for those skilled in the art that other drawings can be obtained according to the drawings without creative efforts.

FIG. 1 is a process flow diagram of a method of electroplating Pt on a metallic conductive pattern in an embodiment of the invention;

FIGS. 2 and 3 are optical microscope illustrations of a conductive substrate before plating in example 1 of the present invention;

FIGS. 4 and 5 are optical microscope illustrations of a conductive substrate after plating in example 1 of the present invention;

FIG. 6 is a parameter chart of the test of the beam portion of the plated conductive substrate using the step meter according to example 1 of the present invention;

FIG. 7 is a current chart of an electroplating process in example 2 of the present invention;

FIG. 8 is a parameter diagram of the test of the line dense region of the electroplated conductive substrate using the step profiler in example 2 of the present invention;

FIG. 9 is an optical microscope representation of a conductive substrate after plating in example 3 of the invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "upper", "lower", "horizontal", "inside", "outside", and the like, indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, are only for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means two or more unless specifically defined otherwise.

An embodiment of the present invention provides a method for electroplating Pt on a metal conductive pattern, and referring to fig. 1, the method includes the steps of:

s10, providing a substrate with a metal conductive pattern, and carrying out surface hydrophilic treatment on the substrate.

The substrate having a metal conductive pattern is, for example, a conductive pattern of metal such as gold, nickel, or molybdenum formed on glass or a silicon wafer, and the conductive pattern is formed by, for example, an etching process or a printing process.

In an embodiment of the present invention, the method of performing surface hydrophilicity treatment on the substrate may be:

(1) soaking the substrate in a mixed solution of hydrochloric acid and hydrogen peroxide for 30-60 min, such as 30min, 40min, 50min or 60 min; wherein the volume ratio of the hydrochloric acid to the hydrogen peroxide is 1: 1-1: 5, for example, 1:1, 1:2, 1:3, 1:4 or 1: 5. More specifically, the hydrochloric acid has a concentration of 0.1M to 0.5M, such as 0.1M, 0.2M, 0.3M, 0.4M or 0.5M, and the hydrogen peroxide has a volume concentration of 10% to 30%, such as 10%, 15%, 20%, 25% or 30%.

In a more preferable scheme, the substrate is soaked in a mixed solution of hydrochloric acid and hydrogen peroxide in a volume ratio of 1:1 for 30min, wherein the concentration of the hydrochloric acid is 0.2M, and the volume concentration of the hydrogen peroxide is 10%.

(2) Soaking the substrate in a mixed solution of hydrochloric acid and ammonia water for 30-60 min, such as 30min, 40min, 50min or 60 min; wherein the volume ratio of the hydrochloric acid to the ammonia water is 1: 1-1: 3, such as 1:1, 1:1.5, 1:2, 1:2.5 or 1: 3. More specifically, the hydrochloric acid has a concentration of 0.1M to 0.5M, for example 0.1M, 0.2M, 0.3M, 0.4M or 0.5M, and the aqueous ammonia has a volume concentration of 10% to 30%, for example 10%, 15%, 20%, 25% or 30%.

In a more preferable scheme, the substrate is placed in a mixed solution of hydrochloric acid and ammonia water in a volume ratio of 1:2 for soaking treatment for 40min, wherein the concentration of the hydrochloric acid is 0.2M, and the volume concentration of the ammonia water is 20%.

In a preferred embodiment, the substrate is first subjected to a conventional cleaning treatment using a cleaning agent, and then to a surface hydrophilicity treatment, which is performed to rinse the substrate again and uses high purity nitrogen (N)₂99.999%) was dried.

S20, preparing an electroplating solution for electroplating Pt, and electroplating the metal conductive pattern in the electroplating solution to form a Pt plating layer.

In this case, the electrolyte material is dissolved in water (preferably deionized water) to prepare a plating solution. In the embodiment of the present invention, the plating solution is a chloroplatinic acid solution with a concentration of 20mM to 60mM, such as 20mM, 30mM, 40mM, 50mM or 60mM, preferably 50 mM.

In an embodiment of the present invention, the electroplating the Pt plating layer on the metal conductive pattern in the electroplating solution includes: and in the electroplating solution, the substrate is used as a working electrode, and a three-electrode electroplating system is adopted to electroplate on the metal conductive pattern to form a Pt coating. In the three-electrode electroplating system, the reference electrode is an Ag/AgCl standard electrode, and the counter electrode is a platinum sheet electrode. Wherein, before the electroplating is started, the substrate with the metal conductive pattern is subjected to a linear sweep voltammetry test (LSV) to determine relevant electroplating parameters.

In the embodiment of the invention, when a three-electrode electroplating system is adopted for electroplating: a potential scanning rate of 0.001V/s to 0.1V/s, for example, 0.001V/s, 0.005V/s, 0.01V/s, 0.02V/s, 0.03V/s, 0.05V/s, 0.08V/s, or 0.1V/s; the working voltage is-0.5V, such as-0.5V, -0.4V, -0.3V, -0.2V, -0.1V, 0.2V, 0.3V, 0.4V or 0.5V; the operating current is 0.2 mA-2 mA, such as 0.2mA, 0.4mA, 0.6mA, 0.8mA, 1mA, 1.2mA, 1.5mA, 1.8mA or 2 mA; the electroplating time is 10min to 30min, for example 10min, 12min, 15min, 20min, 25min or 30 min.

In a preferable scheme, the working voltage is selected to be-0.1V, the working current is selected to be 0.6 mA-1 mA, and the electroplating time is selected to be 10 min-15 min.

And S30, sequentially cleaning and drying the substrate on which the Pt plating layer is formed.

Specifically, the substrate on which the Pt plating layer is formed is placed in deionized water to be cleaned and then dried by blowing compressed nitrogen.

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments.

Example 1

The method for electroplating the Pt film layer on the conductive substrate with the complex metal conductive pattern obtained after photoetching comprises the following process steps:

(1) the method for pretreating the conductive substrate with the complex metal conductive pattern obtained after photoetching specifically comprises the following steps:

a. cutting the conductive substrate to 1 × 2cm by using a silicon wafer cutter²Size;

b. immersing the cut conductive substrate into an absolute ethyl alcohol solution, and carrying out ultrasonic treatment for 15 min;

c. soaking the conductive substrate in a mixed solution of hydrochloric acid and hydrogen peroxide (volume ratio is 1:1), and standing for 30 min; wherein the concentration of the hydrochloric acid is 0.2M, and the volume concentration of the hydrogen peroxide is 10 percent;

d. removing the photoresist from the electrode contact portion with organic solution such as acetone, rinsing with high-purity nitrogen (N)₂99.999%) was dried on the conductive substrate.

(2) Adding 1g of chloroplatinic acid hydrate (more than or equal to 99.9 percent trace metals basis) and 50mL of deionized water into a beaker, and fully stirring at room temperature to obtain a transparent and uniform dark yellow solution as electroplating solution;

(3) and (3) adding the electroplating solution obtained in the step (2) into an electrolytic bath, fixing the conductive substrate pretreated in the step (1) on a working electrode, and soaking the conductive substrate in the electroplating solution to enable the conductive surface of the conductive substrate to be opposite to a counter electrode (platinum sheet electrode).

(4) The electrochemical workstation was used to first perform an LSV scan, in this example, it was determined that electroplating was performed for 15min using a voltage of 0.1V, at which time the average magnitude of the current was around 0.6 mA.

FIGS. 2 and 3 are patterns under an optical microscope of the conductive substrate processed in the above step (1); fig. 4 and 5 are patterns of the conductive substrate under an optical microscope after the plating is performed in the above step (3). As can be seen from fig. 4 and 5, a uniform and dense plating layer having a distinct metallic luster was formed on the conductive substrate.

As shown in fig. 6, which is a parameter chart of the test of the beam portion of the conductive substrate after the electroplating using the step meter, it can be seen from fig. 6 that the Pt plating layer obtained by the electroplating on the conductive substrate of the present embodiment has a stable and uniform thickness with an average thickness of about 1 μm.

Example 2

The method for electroplating the Pt film layer on the conductive substrate with the complex metal conductive pattern obtained after photoetching comprises the following process steps:

(1) the method for pretreating the conductive substrate with the complex metal conductive pattern obtained after photoetching specifically comprises the following steps:

a. cutting the conductive substrate to 1 × 2cm by using a silicon wafer cutter²Size;

b. immersing the cut conductive substrate into an absolute ethyl alcohol solution, and carrying out ultrasonic treatment for 15 min;

c. soaking the conductive substrate in a mixed solution of hydrochloric acid and ammonia water (volume ratio is 1:2), and standing for 60 min; wherein the concentration of the hydrochloric acid is 0.2M, and the volume concentration of the ammonia water is 20%.

d. Removing the photoresist from the electrode contact portion with organic solution such as acetone, rinsing with high-purity nitrogen (N)₂99.999%) was dried on the conductive substrate.

(2) Adding 1g of chloroplatinic acid hydrate (more than or equal to 99.9 percent trace metals basis) and 50mL of deionized water into a beaker, and fully stirring at room temperature to obtain a transparent and uniform dark yellow solution as electroplating solution;

(3) and (3) adding the electroplating solution obtained in the step (2) into an electrolytic bath, fixing the conductive substrate pretreated in the step (1) on a working electrode, and soaking the conductive substrate in the electroplating solution to enable the conductive surface of the conductive substrate to be opposite to a counter electrode (platinum sheet electrode).

(4) And (3) firstly carrying out LSV scanning by using an electrochemical workstation, and determining that the electroplating is carried out for 15min by using a voltage of-0.1V, wherein the current is about 1 mA.

As shown in FIG. 7, the surface of the conductive substrate in the example was plated with-0.1V, and the average current during the plating was about 1 mA.

As shown in fig. 8, which is a parameter diagram of the electroplated conductive substrate in which the line dense area is tested by using a step profiler, it can be seen from fig. 8 that the average thickness of the Pt plating layer in the line dense area on the conductive substrate is about 1 μm, and the thickness of the Pt plating layer is relatively stable and uniform.

Example 3

The method for electroplating the Pt film layer on the conductive substrate with the complex metal conductive pattern obtained after photoetching comprises the following process steps:

(1) pretreating the conductive substrate with complex metal conductive pattern obtained by photoetching

The method comprises the following steps:

a. cutting the conductive substrate to 1 × 2cm by using a silicon wafer cutter²Size;

b. immersing the cut conductive substrate into an absolute ethyl alcohol solution, and carrying out ultrasonic treatment for 15 min;

c. the photoresist on the electrode contact portion was removed by using an organic solution such as acetone, and the conductive substrate was dried with high-purity nitrogen (N2, 99.999%) after rinsing.

(2) Adding 1g of chloroplatinic acid hydrate (more than or equal to 99.9 percent trace metals basis) and 50mL of deionized water into a beaker, and fully stirring at room temperature to obtain a transparent and uniform dark yellow solution as electroplating solution;

(3) and (3) adding the electroplating solution obtained in the step (2) into an electrolytic bath, fixing the conductive substrate cleaned in the step (1) on a working electrode, and soaking the conductive substrate in the electroplating solution to enable the conductive surface of the conductive substrate to be opposite to a counter electrode (platinum sheet electrode).

(4) The electrochemical workstation was used to first perform an LSV scan, in this example, it was determined that electroplating was performed for 15min using a voltage of 0.1V, at which time the average magnitude of the current was around 0.8 mA.

Fig. 9 shows the pattern of the electroplated conductive substrate under the optical microscope in this embodiment. As can be observed from fig. 9, the Pt plating layer on the surface of the conductive substrate without pretreatment had various degrees of peeling and breakage, and the uniformity and stability of the Pt plating layer were poor.

In summary, in the method for electroplating Pt on a metal conductive pattern according to the embodiments of the present invention, a surface hydrophilic treatment is performed on a substrate having a metal conductive pattern, and then a Pt metal layer is electroplated, so that an adhesion between a Pt plating layer and the substrate is improved, and thus stability and uniformity of a metal Pt plating layer obtained by electroplating are improved.

The foregoing is considered as illustrative only of the preferred embodiments of the invention, and is presented merely for purposes of illustration and description of the principles of the invention and is not intended to limit the scope of the invention in any way. Any modifications, equivalents and improvements made within the spirit and principles of the invention and other embodiments of the invention without the creative effort of those skilled in the art are included in the protection scope of the invention based on the explanation here.