Electrode and application and preparation method thereof
By using Ta-Ta alloy or Ti-Pd alloy as the intermediate layer and noble metal oxide as the catalytic layer in the reverse pulse plating electrode, the coating peeling problem caused by the interface corrosion of the titanium electrode is solved, significantly extending the electrode life and improving corrosion resistance.
Patent Information
- Application Number
- CN202280100672.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2022-10-02
- Publication Date
- 2025-06-03
AI Technical Summary
During the reverse pulse plating process, the interface between the coating of the titanium electrode and the substrate is highly corroded, resulting in the problem of abnormal coating peeling.
An electrode structure including a substrate, an intermediate layer and a catalytic layer is adopted, wherein the intermediate layer can be a metal Ta layer, a Ti-Ta alloy layer or a Ti-Pd alloy layer, and the catalytic layer can be a noble metal oxide layer, which is prepared by vapor deposition and coating-heat treatment method.
By forming a stable, dense oxide layer, corrosion at the electrode interface is significantly reduced, the life of the electrode is extended, and a good balance between oxidation resistance and corrosion resistance is achieved.
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Figure CN120092107A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to, but is not limited to, the field of electrochemistry, and in particular to, but is not limited to, electrodes and their uses and preparation methods. Background Art
[0002] Printed circuit boards are a major component of electronic devices and are widely used as a connection carrier for integrated electronic devices and other devices. Electroplating, such as reverse pulse plating (RPP) of copper, is a common method for preparing printed circuit boards.
[0003] Reverse pulse plating of copper relying on the redox reaction of iron ions has a very wide application in printed circuit board electroplating. In these applications, in addition to copper sulfate and sulfuric acid that should be present for conventional copper plating, the electroplating solution also contains a large amount of divalent / trivalent iron ions, and no oxygen evolution reaction occurs on the surface of the anode, but only the redox reaction of iron ions occurs. In an environment lacking anodic polarization, a stable oxide layer cannot be formed on the surface of titanium used as a valve metal. Especially in the flash plating mode of this pulsed electroplating, the concentration of sulfuric acid in the plating solution is as high as 200 g / L to 250 g / L, which is highly corrosive to the interface between the titanium electrode coating and the substrate, resulting in frequent abnormal coating peeling during use. Summary of the Invention
[0004] The following is an overview of the subject matter described in detail herein. The summary of the invention is not intended to limit the scope of protection of the claims.
[0005] After years of careful research, the inventors of the present application found that the key cause of abnormal coating peeling lies in the corrosion of the interface. In order to improve the lifespan of the electrode in reverse pulse plating applications, the corrosion resistance of the electrode is improved.
[0006] The present application provides an electrode comprising a substrate, an intermediate layer, and a catalytic layer, wherein the intermediate layer can be selected from a metal Ta layer, a Ti-Ta alloy layer, or a Ti-Pd alloy layer, and the catalytic layer can be selected from a noble metal oxide layer.
[0007] In some embodiments, the content of Ta in the intermediate layer Ti-Ta alloy layer can be not less than 10 wt% of the total mass of the alloy, further not less than 20 wt%, and still further 40 wt% to 50 wt%.
[0008] In some embodiments, the content of Pd in the intermediate layer Ti-Pd alloy layer can be 0.01 wt% to 0.25 wt% of the total mass of the alloy, and further 0.12 wt% to 0.25 wt%.
[0009] In some embodiments, the loading amount of Ta in the intermediate layer Ta layer or the intermediate layer Ti-Ta alloy layer can be 1 g / m2 to 10 g / m 2 and further can be 4 g / m 2 or 5 g / m 2 。
[0010] In some embodiments, the loading amount of Ti in the intermediate layer Ti-Pd alloy layer can be 1 g / m 2 to 10 g / m 2 and further can be 4 g / m 2 or 5 g / m 2 。
[0011] In some embodiments, the substrate can be selected from metallic Ti or Ti-based alloys.
[0012] In some embodiments, the catalytic layer can be selected from Ru-Ti mixed metal oxides, Ir-Ti mixed metal oxides, Ru-Ir-Ti mixed metal oxides, Ru-Ta mixed metal oxides, Ir-Ta mixed metal oxides, or Ru-Ir-Ta mixed metal oxides.
[0013] In some embodiments, the content of Ti or Ta in the catalytic layer can be 10 wt% to 60 wt% of the total mass of the metal elements.
[0014] In some embodiments, the loading amount of Ru or Ir in the catalytic layer can be 2 g / m 2 to 20 g / m 2 further can be 5 g / m 2 to 10 g / m 2 and still further can be 6 g / m 2 or 8 g / m 2 。
[0015] The present application further provides the use of the above electrode, and the electrode can be used as an anode for electroplating, further for pulse electroplating, and still further for reverse pulse electroplating.
[0016] In some embodiments, the reverse pulse electroplating can be the reverse pulse electroplating of copper, where ferrous ions are used as the redox pair for the anodic reaction.
[0017] In some embodiments, the reverse pulse electroplating can be used for preparing printed circuit boards.
[0018] The present application further provides a method for preparing the above electrode, the method comprising: providing an electrode substrate; forming an intermediate layer on the substrate by a vapor deposition method (such as a magnetron sputtering method); and forming a catalytic layer on the intermediate layer by a coating-thermal treatment method.
[0019] Other features and advantages of the present application will be set forth in the following description, or may be learned by practice of the present application. Other advantages of the present application can be realized and obtained through the solutions described in the description and the drawings. After reading and understanding the drawings and the specific embodiments, other aspects will be understood. Description of the Drawings
[0020] The drawings are used to provide an understanding of the technical solutions of the present application and form a part of the description. They are used to explain the technical solutions of the present application together with the embodiments of the present application and do not constitute a limitation to the technical solutions of the present application.
[0021] Figure 1 is a cross-sectional view of the electrode prepared in Example 1 under a scanning electron microscope (SEM).
[0022] Figure 2 is a view of the surface of the electrode prepared in Example 1 under a scanning electron microscope (SEM).
[0023] In the drawings: 1. Substrate; 2. Intermediate layer; and 3. Catalytic layer. Detailed Description of the Embodiments
[0024] The embodiments of the present application will be described in detail below with reference to the drawings. It should be noted that as long as there is no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other arbitrarily.
[0025] The embodiments of the present application provide an electrode. For example, the electrode includes a substrate, an intermediate layer, and a catalytic layer stacked in sequence from bottom to top. The intermediate layer and the catalytic layer may also be symmetrically arranged on both sides of the substrate.
[0026] The substrate may be metallic titanium (Ti) or a Ti-based alloy, such as a Ti-Nb alloy containing a small amount of Nb, a Ti-Ta alloy containing a small amount of Ta, or a Ti-Nb-Ta alloy containing a small amount of Nb and Ta. For example, the total content of Nb and Ta does not exceed 5 wt% of the total mass of the alloy. The substrate may be a metallic titanium mesh.
[0027] The intermediate layer can be a metal Ta or Ti alloy, such as a Ti-Ta alloy or a Ti-Pd alloy, and further such as ASTM grade 7 or ASTM grade 11 Ti alloy, etc. The content of Ta in the Ti-Ta alloy can be not less than 10 wt% of the total mass of the alloy, further not less than 20 wt%, and still further be 40 wt% to 50 wt%. For example, the mass ratio of Ta to Ti can be 40:60, 50:50, etc. The content of Pd in the Ti-Pd alloy can be 0.01 wt% to 0.25 wt% of the total mass of the alloy, further be 0.12 wt% to 0.25 wt%. For example, 0.15 wt%, 0.18 wt%, 0.20 wt%, etc. Such alloy content can provide better oxidation resistance and better corrosion resistance simultaneously.
[0028] The intermediate layer can be prepared by a vapor deposition method (such as a magnetron sputtering method, a chemical vapor deposition method, etc.). The loading amount of Ta in the intermediate layer metal Ta layer or the intermediate layer Ti-Ta alloy layer can be 1 g / m 2 to 10 g / m 2 , for example, 4 g / m 2 , 5 g / m 2 , etc. The loading amount of Ti in the intermediate layer Ti-Pd alloy layer can be 1 g / m 2 to 10 g / m 2 , for example, 4 g / m 2 or 5 g / m 2 , or the loading amount of Pd in the intermediate layer Ti-Pd alloy layer can be 0.1 mg / m 2 to 25 mg / m 2 , for example 1 mg / m 2 , 5 mg / m 2 , 10 mg / m 2 , 15 mg / m 2 , etc. The magnetron sputtering method can especially enable a dense intermediate layer to be formed on the substrate, which further improves the corrosion resistance.
[0029] In an example of the magnetron sputtering method, the temperature of the substrate is controlled to be 200 °C to 400 °C, an inert gas is used as the sputtering gas, the vacuum degree is 0.1 Pa to 0.5 Pa, the power of the DC power supply is 100 W to 500 W, the target-substrate distance is 30 mm to 100 mm, and the required loading amount is obtained by controlling the ratio of the target materials used simultaneously and adjusting the sputtering time.
[0030] The material of the catalytic layer can be Ru-Ti mixed metal oxide, Ir-Ti mixed metal oxide, Ru-Ir-Ti mixed metal oxide, Ru-Ta mixed oxide, Ir-Ta mixed oxide or Ru-Ir-Ta mixed oxide, and the content of Ti or Ta element in the catalytic layer can be 10wt% to 60wt% of the total mass of metal elements, such as 20wt%, 30wt%, 40wt%, 50wt%, etc. The loading amount of Ru or Ir in the catalytic layer can be 2g / m 2 to 20g / m 2 and further is 5g / m 2 to 10g / m 2 , for example, 6g / m 2 , 8g / m 2 etc.
[0031] The catalytic layer can be prepared by a coating-thermal treatment method. The catalytic layer is formed by the following steps: coating a coating solution containing Ru and Ti, a coating solution containing Ir and Ti, a coating solution containing Ru, Ir and Ti, a coating solution containing Ru and Ta, a coating solution containing Ir and Ta, or a coating solution containing Ru, Ir and Ta on the surface of the intermediate layer, and drying and heat-treating. This coating-thermal treatment process can be carried out several times until the desired loading amount is obtained.
[0032] The electrode of the present application is suitable for use as an anode for reverse pulse electroplating, especially for reverse pulse electroplating of copper, for preparing printed circuit boards. By arranging the intermediate layer as described above, a stable, dense and highly corrosion-resistant oxide layer can be formed on the substrate, thereby reducing the corrosion of the interface between the substrate and the coating (especially the noble metal oxide coating), and achieving a good balance between oxidation resistance and corrosion resistance.
[0033] The present application has the following beneficial effects:
[0034] For the electrode of the present application, before coating the catalytic layer, a corrosion-resistant valve metal intermediate layer (for example, a metal Ta layer, a Ti-Ta alloy layer or a Ti-Pd alloy layer) is first produced on the substrate by a vapor deposition method. Due to the presence of this alloy intermediate layer, the corrosion resistance of the electrode in a high-concentration sulfuric acid solution is improved, and the service life of the titanium-coated anode in reverse pulse electroplating applications is greatly extended.
[0035] Example 1
[0036] Use metallic titanium (Ti) as the electrode substrate. Select a titanium plate that meets the requirements of ASTM-B265 grade 1 and stamp it to obtain a 2mm-thick titanium mesh with a grid factor of 2.0, and then sandblast it with iron sand and impregnate it with sulfuric acid.
[0037] An intermediate layer of Ta-Ti alloy is formed on a Ti substrate by magnetron sputtering. The mass ratio of Ta to Ti in the alloy is 40:60, and the loading of Ta in the alloy layer is 4 g / m 2 . Specifically, the titanium substrate is placed in a single-chamber magnetron sputtering system, the temperature of the titanium substrate is controlled at 300 °C, and magnetron sputtering is carried out; wherein the sputtering gas is commercially available high-purity argon, the vacuum degree is 0.3 Pa, the power of the DC power supply is 200 W, the target-substrate distance is 50 mm, the titanium target and tantalum target are used together by controlling the ratio of the target materials, and the sputtering lasts for 10 minutes.
[0038] A catalytic layer of Ir-Ta mixed metal oxide is formed on the intermediate layer, wherein the loading of Ir is 8 g / m 2 . Aqueous iridium chloride solution and tantalum pentachloride salt are used to prepare a n-butanol solution with an iridium mass concentration of 3 wt%, wherein the mass ratio of iridium element to tantalum element is 2:1. This solution is applied to the surface of the anode with a brush. Each time when 1 g of iridium is applied per square meter of the coating, the anode is dried at 80 °C and heat-treated at 500 °C for 10 minutes, and then taken out to cool and continue coating until the iridium loading target of 8 g / m 2 is achieved.
[0039] An electrode is prepared thereby.
[0040] Example 2
[0041] The same metallic titanium (Ti) as in Example 1 is used as the electrode substrate.
[0042] An intermediate layer of Ta-Ti alloy is formed on a Ti substrate by magnetron sputtering. The mass ratio of Ta to Ti in the alloy is 50:50, and the loading of Ta in the alloy layer is 5 g / m 2 . The formation steps of the intermediate layer are the same as those in Example 1, except for the alloy ratio and loading.
[0043] A catalytic layer of Ir-Ta mixed metal oxide is formed on the intermediate layer, wherein the loading of Ir is 6 g / m 2 . The formation steps of the catalytic layer are the same as those in Example 1, except for the loading.
[0044] An electrode is prepared thereby.
[0045] Example 3
[0046] The same metallic titanium (Ti) as in Example 1 is used as the electrode substrate.
[0047] An intermediate layer of Ta-Ti alloy is formed on a Ti substrate by chemical vapor deposition. The mass ratio of Ta to Ti in the alloy is 50:50, and the loading of Ta in the alloy layer is 5 g / m 2 . Specifically, titanium dichloride is selected as the titanium source, tantalum dichloride is selected as the tantalum source, and hydrochloric acid is used as the solvent; they are introduced into a reaction chamber at 500 °C and deposited for 20 minutes to reach a predetermined deposition amount.
[0048] A catalytic layer of Ir-Ta mixed metal oxide is formed on the intermediate layer, where the loading of Ir is 8 g / m 2 . The formation steps of the catalytic layer are the same as those in Example 1, except for the loading.
[0049] An electrode is prepared therefrom.
[0050] Comparative Example 1
[0051] The same metallic titanium (Ti) as in Example 1 is used as the electrode substrate.
[0052] A catalytic layer of Ir-Ta mixed metal oxide is formed on the Ti substrate, where the loading of Ir is 12 g / m 2 . The formation steps of the catalytic layer are the same as those in Example 1, except for the loading.
[0053] An electrode is prepared therefrom.
[0054] Comparative Example 2
[0055] The same metallic titanium (Ti) as in Example 1 is used as the electrode substrate.
[0056] A ceramic oxide intermediate layer is formed on the Ti substrate. A n-butanol solution of titanium trichloride and tantalum pentachloride (where the mass percentages of the metallic elements of titanium and tantalum are both 2%) is coated on a titanium mesh at a standard of 1 g of metallic element per layer / m 2 . Then the titanium mesh is dried at 80 °C and heat-treated at 500 °C for 1 hour, and then taken out to cool and continue coating until a final amount of 3 g of metallic element / m 2 .
[0057] A catalytic layer of Ir-Ta mixed metal oxide is formed on the intermediate layer, where the loading of Ir is 12 g / m 2 . The formation steps of the catalytic layer are the same as those in Example 1, except for the loading.
[0058] An electrode is prepared therefrom.
[0059] Electrode microstructure
[0060] The electrode prepared in Example 1 was tested by scanning electron microscopy.
[0061] The cross-sectional view of the electrode is shown in Figure 1 . As can be seen from Figure 1 , the intermediate layer can cover the surface of the titanium substrate without cracks, which can avoid the corrosion of the titanium substrate to a greater extent in subsequent applications.
[0062] The surface view of the electrode is shown in Figure 2 . As can be seen from Figure 2 , the intermediate layer has no effect on the surface of the iridium-tantalum catalytic layer, and the surface of the catalytic layer still exhibits a normal pattern formed by the precipitated iridium element.
[0063] Electrode life test
[0064] Using a pulsed power supply, the electrodes of the examples and comparative examples were used as anodes respectively. The cut anode was connected to a titanium plate cathode of the same size through a polypropylene bolt. The electrode spacing was 3 cm. The test electrode (anode) was connected to the positive pole, and the titanium cathode was connected to the negative pole. The electrolyte was a mixed solution of copper sulfate (Cu 35 g / L) and sulfuric acid (H 2 SO 4 2 30 g / L), to which ferrous sulfate (with a ferrous concentration of 17 g / L) was added. A forward current with an intensity of 800 A / m 2 was applied for 19 milliseconds, and then a reverse current with an intensity of 2400 A / m 2 was applied for 1 millisecond, and these steps were cycled for pulse plating, where the temperature of the plating solution was maintained at 40 °C.
[0065] The lives of the electrodes of the examples and comparative examples were tested by adhesion performance testing. Specifically, 3M tape was adhered to the surface of the anode that had undergone cyclic pulse electroplating, and then the tape was pulled down to observe whether the coating could be torn off to expose the titanium substrate. If the titanium substrate could be significantly exposed, it indicated that the interface between the coating and the titanium substrate had separated and the coating had failed.
[0066] The test results are shown in Table 1.
[0067] Table 1 Life of the electrodes
[0068]
[0069] As can be seen from Table 1, the lives of the electrodes in Examples 1 - 3 of this application (with a Ta-Ti alloy intermediate layer) are longer than those of the electrodes in Comparative Example 1 (without an intermediate layer). Specifically, the life of the electrode in Example 2 is as high as 2970 kAh / m 2, which is about 3.2 times the lifespan of the electrode in Comparative Example 1. The main reason is that after applying the Ta-Ti alloy intermediate layer, the surface of the alloy is oxidized, and a dense and highly corrosion-resistant Ti-Ta oxide layer is formed at the interface between the Ti substrate and the Ir-Ta catalytic layer, and the wear rate of Ir in the catalytic layer is extremely low. Therefore, the corrosion resistance of the electrode is improved and its lifespan is extended.
[0070] In addition, as can be seen from Table 1, the lifespan of the electrodes in Examples 1-3 of the present application (with Ta-Ti alloy intermediate layers) is longer than that of the electrodes in Comparative Example 2 (with ceramic oxide intermediate layers). Specifically, the lifespan of the electrode in Example 2 is about 3.9 times that of the electrode in Comparative Example 2. The main reason is that the ceramic oxide is loose and porous and cannot effectively protect the titanium substrate from corrosion; while in the electrodes of the examples of the present application, a dense and highly corrosion-resistant Ti-Ta oxide layer is formed at the interface between the Ti substrate and the Ir-Ta catalytic layer.
[0071] For Examples 1-3, the electrodes with intermediate layers prepared by the magnetron sputtering method (Examples 1 and 2) have a longer lifespan than the electrodes with intermediate layers prepared by the chemical vapor deposition method (Example 3), mainly because the metal layer formed by physical vapor deposition is denser, which helps to protect the substrate from corrosion.
[0072] Among Examples 1-2 where the intermediate layers are all prepared by the magnetron sputtering method, the loading amount in Example 2 is higher than that in Example 1, and the lifespan in Example 2 is longer than that in Example 1, mainly because the Ta loading amount in Example 2 is higher, thus improving the corrosion resistance. However, if the Ta content is too high, the adhesion of the coating will decrease; and if the Ta content is too low, the corrosion resistance will decrease. Therefore, the content of Ta in the intermediate layer is 40wt%-50wt% of the total mass of the alloy, which obtains beneficial results.
[0073] Although the embodiments disclosed in the present application are as described above, the content described is only an embodiment adopted for the convenience of understanding the present application and is not used to limit the present application. Any person skilled in the art in the field of the present application can make any modifications and changes to the implementation forms and details without departing from the spirit and scope disclosed in the present application. However, the scope of patent protection of the present application should still be subject to the scope defined by the appended claims.
Claims
1. An electrode, which comprises a substrate, an intermediate layer, and a catalytic layer; wherein the intermediate layer is selected from a metal Ta layer, a Ti-Ta alloy layer, or a Ti-Pd alloy layer; and the catalytic layer is selected from noble metal oxide layers.
2. The electrode according to claim 1, wherein, the content of Ta in the intermediate layer Ti-Ta alloy layer is not less than 10 wt% of the total mass of the alloy, preferably not less than 20 wt%, and more preferably 40 wt% to 50 wt%; the content of Pd in the intermediate layer Ti-Pd alloy layer is 0.01 wt% to 0.25 wt% of the total mass of the alloy, preferably 0.12 wt% to 0.25 wt%.
3. The electrode according to claim 1 or claim 2, wherein, The loading amount of Ta in the intermediate layer metal Ta layer or the intermediate layer Ti-Ta alloy layer is 1 g / m 2 to 10 g / m 2 , preferably 4 g / m 2 or 5 g / m 2 ; the loading amount of Ti in the intermediate layer Ti-Pd alloy layer is 1 g / m 2 to 10 g / m 2 , preferably 4 g / m 2 or 5 g / m 2 .
4. The electrode according to any one of claims 1-3, wherein, the substrate is selected from metal Ti or Ti-based alloys.
5. The electrode according to any one of claims 1-4, wherein, the catalytic layer is selected from Ru-Ti mixed metal oxides, Ir-Ti mixed metal oxides, Ru-Ir-Ti mixed metal oxides, Ru-Ta mixed metal oxides, Ir-Ta mixed metal oxides, or Ru-Ir-Ta mixed metal oxides.
6. The electrode according to any one of claims 1-5, wherein, the content of Ti or Ta in the catalytic layer is 10 wt% to 60 wt% of the total mass of metal elements.
7. The electrode according to any one of claims 1-6, wherein, The loading amount of Ru or Ir in the catalytic layer is 2 g / m 2 to 20 g / m 2 Preferably, it is 5 g / m 2 to 10 g / m 2 More preferably, it is 6 g / m 2 or 8 g / m 2 .
8. Use of the electrode according to any one of claims 1-7, the electrode being used as an anode for electroplating, preferably for pulse electroplating, and more preferably for reverse pulse electroplating.
9. The use according to claim 8, wherein, the reverse pulse electroplating is reverse pulse electroplating of copper, wherein ferrous ions are used as the redox pair for the anodic reaction.
10. The use according to claim 8 or claim 9, wherein, the reverse pulse electroplating is used for preparing printed circuit boards.
11. A method for preparing the electrode according to any one of claims 1-7, the method comprising: providing an electrode substrate; forming an intermediate layer on the substrate by a vapor deposition method, preferably by a magnetron sputtering method; and forming a catalytic layer on the intermediate layer by a coating-thermal treatment method.