Electrodes and their uses

Abstract

An electrode and its use. The electrode includes a substrate, a catalyst layer, and a protective layer, the catalyst layer being selected from a mixed metal oxide layer, the protective layer being selected from an organic ionomer layer, and may further include a surface coating between the catalyst layer and the protective layer, and may further include an intermediate layer between the substrate and the catalyst layer. The electrode can be used as an anode for surface treatment applications.

Description

[Technical Field]

[0001] This application relates to the field of electrochemistry, but is not limited thereto, and in particular, but not exclusively, to electrodes and methods of using same. [Background technology]

[0002] Printed circuit boards are a key component of electronic devices and are widely used as connection carriers for integrated electronics and other devices. Electroplating, such as vertical conveyor plating (VCP), is a common method for fabricating printed circuit boards.

[0003] In the application of copper VCP for printed circuit boards, metal electrodes with mixed metal oxide (MMO) coatings are traditionally used as anodes, and additives such as carriers, brighteners, and leveling agents are usually required to achieve fine grain, non-directional copper grain structure, and uniform copper thickness. In this case, for MMO-coated anodes, it is necessary to prevent contact between metal (e.g., Ir) active sites and additive molecules to avoid additive consumption. Compared with Cu-P alloy anodes, MMO-coated anodes have a much higher additive consumption rate. Summary of the Invention

[0004] The following is a summary of the subject matter described in detail herein, which is not intended to limit the scope of protection of the claims.

[0005] To reduce additive consumption rates and manufacturing costs, the inventors of the present application have made improvements to MMO coated electrodes through years of careful research.

[0006] The present application provides an electrode including a substrate, a catalyst layer, and a protective layer, wherein the catalyst layer may be selected from a mixed metal oxide layer, and the protective layer may be selected from an organic ionomer layer, for example, a fluororesin layer, and may be, for example, a sulfonated tetrafluoroethylene layer, and may be, for example, Nafion.

[0007] In some embodiments, a surface coating may further be included between the catalyst layer and the protective layer, and the surface coating may be selected from a Ta oxide layer, for example, a Ta2O5 layer.

[0008] In some embodiments, an intermediate layer may further be included between the substrate and the catalyst layer, and the intermediate layer may be selected from a Ta oxide layer, a Ti oxide layer, a Ti-Ta mixed metal oxide layer, a Ti-Ta alloy layer, or a Ti-Pd alloy layer.

[0009] In some embodiments, the catalyst layer and the surface coating may be multiple alternating layers.

[0010] In some embodiments, the loading of the protective layer is 1 g / m 2 ~10g / m 2 and 2 g / m 2 ~5g / m 2 may be.

[0011] In some embodiments, the Ta content in the surface coating is 1 g / m 2 ~20g / m 2 and 10 g / m 2 ~15g / m 2 may be.

[0012] In some embodiments, the catalyst layer can be selected from a Ru-Ti mixed metal oxide layer, an Ir-Ti mixed metal oxide layer, a Ru-Ir-Ti mixed metal oxide layer, a Ru-Ta mixed metal oxide layer, an Ir-Ta mixed metal oxide layer, a Ru-Ir-Ta mixed metal oxide layer, or a Pt-Ir mixed metal oxide layer.

[0013] In some embodiments, the content of Ti, Ta, or Pt in the catalyst layer may be 10 wt% to 80 wt%, or may be 20 wt% to 70 wt% of the total mass of the metal elements.

[0014] In some embodiments, the loading of Ru, Ir, or Pt in the catalyst layer is 2 g / m 2 ~20g / m 2 and 5 g / m 2 ~10g / m 2 6 g / m 2 ~8g / m 2 may be.

[0015] In some embodiments, the Ta content in the intermediate Ti-Ta mixed metal oxide layer may be 10 wt% or more of the total mass of the metal elements, 20 wt% or more of the total mass of the metal elements, or even 40 wt% to 50 wt% of the total mass of the metal elements.

[0016] In some embodiments, the Ta content in the Ti-Ta alloy layer of the intermediate layer may be 10 wt% or more of the total mass of the alloy, may be 20 wt% or more of the total mass of the alloy, or may be 40 wt% to 50 wt% of the total mass of the alloy.

[0017] In some embodiments, the Pd content in the Ti—Pd alloy layer of the intermediate layer may be 0.01 wt % to 0.25 wt % of the total mass of the alloy, or may be 0.12 wt % to 0.25 wt % of the total mass of the alloy.

[0018] In some embodiments, the Ta loading in the intermediate Ta oxide layer, the intermediate Ti-Ta mixed metal oxide layer, and the intermediate Ti-Ta alloy layer is 1 g / m 2 ~10g / m 2 and 4 g / m 2 or 5g / m 2 may be.

[0019] In some embodiments, the loading amount of Ti in the intermediate Ti oxide layer and the intermediate Ti-Pd alloy layer is 1 g / m 2 ~10g / m 2 and 4 g / m 2 or 5g / m 2 may be.

[0020] In some embodiments, the substrate may be selected from the metals Ti, Ta, Nb, or alloys thereof.

[0021] The present application further provides the use of the above-mentioned electrode, wherein the electrode may be used as an anode for surface treatment applications, may be used as an anode for plating, and may further be used as an anode for copper plating or an anode for vertical conveyor plating.

[0022] In some embodiments, plating can be used to manufacture printed circuit boards.

[0023] Other features and advantages of the present application will be set forth in detail in the following description. Other advantages of the present application will be realized and obtained by the solutions set forth in the description and drawings. Other aspects will become apparent from a reading and understanding of the accompanying drawings and detailed description. [Brief explanation of the drawings]

[0024] The accompanying drawings are used to provide understanding of the technical solutions of the present application and constitute a part of this specification. The drawings, together with the examples of the present application, are used to explain the technical solutions of the present application and do not constitute limitations on the technical solutions of the present application.

[0025] [Figure 1] FIG. 1 is a scanning electron microscope photograph of the titanium mesh of the electrode substrate produced in Example 1.

[0026] [Figure 2] FIG. 2 is a scanning electron microscope photograph of a top view of the protective layer of the electrode prepared in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0027] Detailed Description of the Embodiments Hereinafter, the embodiments of the present application will be described in detail with reference to the accompanying drawings. Multiple embodiments and multiple features in multiple embodiments of the present application may be arbitrarily combined with each other if not contradictory.

[0028] An embodiment of the present application provides an electrode, for example, the electrode includes a substrate, a catalyst layer, and a protective layer stacked in this order, which can effectively prevent contact between additive molecules and metal active sites, exhibit chemical inertness in the oxygen generation process, and significantly reduce the additive consumption rate.

[0029] The catalyst layer and the protective layer can be symmetrically disposed on both sides of the substrate, or the catalyst layer and the protective layer can be disposed on one side of the substrate and only the catalyst layer can be disposed on the other side of the substrate. The catalyst layer provides electrochemical activity for the oxygen evolution reaction and has properties such as wear resistance and catalytic corrosion stability.

[0030] A surface coating may or may not be provided between the catalyst layer and the protective layer, which can provide a better interface for the adhesion of the protective layer and improve the bond between the protective layer and the catalyst layer.

[0031] An intermediate layer may or may not be provided between the substrate and the catalyst layer, which has excellent corrosion resistance and can provide additional corrosion protection for the substrate.

[0032] The catalyst layer and surface coating may be multiple layers stacked one on top of the other.

[0033] The substrate can be selected from metallic Ti, Ta, Nb, or alloys thereof. For example, the substrate can be metallic titanium (Ti), commercially pure titanium (e.g., ASTM Grade 1 or ASTM Grade 2 commercially pure titanium), or a Ti-based alloy (e.g., ASTM Grade 7 or ASTM Grade 11 titanium 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, where the combined content of Nb and Ta does not exceed 5 wt% of the total mass of the alloy. The substrate can be a mesh, plate, foam, felt, or the like, such as metallic titanium mesh.

[0034] The intermediate layer may be selected from Ta oxide, Ti oxide, Ti-Ta mixed metal oxide, Ti-Ta alloy, or Ti-Pd alloy. The Ta content in the Ti-Ta mixed metal oxide layer may be 10 wt% or more of the total mass of the metal elements, 20 wt% or more of the total mass of the metal elements, or even 40 wt% to 50 wt% of the total mass of the metal elements. For example, the mass ratio of Ta to Ti may be 40:60, 50:50, etc. The Ta content in the Ti-Ta alloy may be 10 wt% or more of the total mass of the alloy, 20 wt% or more of the total mass of the alloy, or even 40 wt% to 50 wt% of the total mass of the alloy. For example, the mass ratio of Ta to Ti may be 40:60, 50:50, etc. The Pd content in the Ti-Pd alloy layer may be 0.01 wt% to 0.25 wt% of the total mass of the alloy, or 0.12 wt% to 0.25 wt% of the total mass of the alloy. For example, the Pd content may be 0.15 wt%, 0.18 wt%, 0.20 wt%, etc. The Ta loading in the Ta oxide layer, the Ti-Ta mixed metal oxide layer, and the Ti-Ta alloy layer is 1 g / m 2 ~10g / m 2 , e.g., 4 g / m 2 , 5g / m 2 The loading amount of Ti in the Ti oxide layer and the Ti-Pd alloy layer may be 1 g / m 2 ~10g / m 2 , e.g., 4 g / m 2or 5g / m 2 Or the loading amount of Pd in ​​the Ti—Pd alloy layer may be 0.1 mg / m 2 ~25mg / m 2 , e.g., 1 mg / m 2 , 5 mg / m 2 , 10 mg / m 2 , 15 mg / m 2 etc.

[0035] The intermediate layer can be produced by a wet chemical method or a vapor deposition method, such as magnetron sputtering, chemical vapor deposition, etc. The use of magnetron sputtering makes it possible to form a high density intermediate layer on the substrate, which can improve corrosion resistance.

[0036] In an example of a magnetron sputtering process, the substrate temperature is controlled to 200 to 400°C, an inert gas is used as the sputtering gas, the vacuum level is 0.1 to 0.5 Pa, the power of the DC power supply is 100 to 500 W, the target-substrate distance is 30 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.

[0037] The catalyst layer can be selected from a Ru-Ti mixed metal oxide layer, an Ir-Ti mixed metal oxide layer, a Ru-Ir-Ti mixed metal oxide layer, a Ru-Ta mixed metal oxide layer, an Ir-Ta mixed metal oxide layer, a Ru-Ir-Ta mixed metal oxide layer, or a Pt-Ir mixed metal oxide layer. The content of Ti, Ta, or Pt in the catalyst layer can be 10 wt% to 80 wt%, for example, 20 wt% to 70 wt%, such as 30 wt%, 40 wt%, 50 wt%, or 60 wt%, of the total mass of the metal elements. The loading amount of Ru, Ir, or Pt in the catalyst layer can be 2 g / m or less. 2 ~20g / m 2 and 5 g / m 2 ~10g / m 2 6 g / m 2 ~8g / m 2 , e.g., 7 g / m 2etc. The catalyst layer provides electrochemical activity for the oxygen evolution reaction and has properties such as attrition resistance and catalytic corrosion stability.

[0038] The catalyst layer can be fabricated by methods such as coating pyrolysis, chemical vapor deposition (e.g., atomic layer deposition (ALD)), plasma thermal spraying, and physical vapor deposition. In an example of coating pyrolysis, the catalyst layer is formed by coating a coating solution containing, for example, Ru and Ti, Ir and Ti, Ru, Ir, and Ti, Ru and Ta, Ir and Ta, Ru, Ir, and Ta, or Pt and Ir on the surface of the intermediate layer or substrate, followed by drying and pyrolysis. The coating pyrolysis process can be performed multiple times until the desired loading is achieved.

[0039] The surface coating may be an oxide of tantalum, for example Ta2O5. The Ta content in the surface coating is less than 1 g / m 2 ~20g / m 2 and 10 g / m 2 ~15g / m 2 , e.g., 11 g / m 2 , 12g / m 2 , 13g / m 2 , 14g / m 2 etc. may also be used.

[0040] The surface coating can be prepared by methods such as coating pyrolysis, chemical vapor deposition (e.g., ALD), plasma thermal spraying, and physical vapor deposition. In the example of coating pyrolysis, the surface coating is formed by coating a Ta-containing coating solution on the surface of the catalyst layer, followed by drying and pyrolysis. The coating pyrolysis process can be performed multiple times until the desired loading amount is obtained.

[0041] The protective layer may be an organic ionomer, for example, a fluororesin, for example, sulfonated tetrafluoroethylene, or even Nafion. The loading of the protective layer is 1 g / m 2 ~10g / m2 and 2 g / m 2 ~5g / m 2 , e.g., 3 g / m 2 , 4g / m 2 etc. may also be used.

[0042] The protective layer can be prepared by methods such as coating pyrolysis, chemical vapor deposition (eg, ALD), plasma thermal spray, and physical vapor deposition.

[0043] The electrodes of the present application are suitable for use as anodes for plating to prepare printed circuit boards, in particular as anodes for copper plating or as anodes for vertical conveyor plating.

[0044] The present application has the following advantageous effects:

[0045] 1. The electrode of the present application has a high-density protective layer (e.g., a fluororesin layer) that can effectively prevent contact between additive molecules and metal active sites, exhibit chemical inertness in the oxygen generation process, and significantly reduce the additive consumption rate.

[0046] 2. The protective layer of the present application may also be ionically conductive, thereby reducing the resistance of the coating to ionic currents.

[0047] 3. The combination of the protective layer and the surface coating (e.g., Ta2O5 layer) in the electrode of the present application brings about a synergistic effect, which can improve the adhesion of the protective layer to the surface coating, and is more advantageous in reducing the additive consumption rate.

[0048] 4. The electrode of the present application has a simple fabrication process and reduced manufacturing costs, which is advantageous for mass production.

[0049] Example 1 Metallic titanium (Ti) was used as the electrode substrate. A 2 mm thick titanium mesh with a lattice coefficient of 2.0, meeting the requirements of ASTM-B265 Grade 1, was selected and then sandblasted with iron sand and pickled with sulfuric acid.

[0050] An Ir-Ta MMO catalyst layer was formed on the substrate, with an Ir loading of 5 g / m 2 An aqueous solution of chloroiridic acid and pentachloride tantalum salt was used to prepare an n-butanol solution with an iridium mass concentration of 3 wt%, with the mass ratio of elemental iridium to elemental tantalum being 65:35. This solution was applied to the surface of the substrate with a brush. After applying 1 g of iridium per square meter of coating, the substrate was dried at 80°C, decomposed at 500°C for 10 minutes, and then removed for cooling. The solution was then coated with 5 g / m 2 Coating was continued until an iridium loading target of 0.01 was reached.

[0051] A Ta2O5 surface coating was formed on the catalyst layer, with a Ta loading of 10 g / m 2 Tantalum pentachloride salt was used to prepare an n-butanol solution with a tantalum mass concentration of 3 wt%. This solution was applied to the surface of the catalyst layer with a brush. After applying 1 g of tantalum per square meter of coating, the object was dried at 80°C, decomposed at 500°C for 10 minutes, then removed for cooling and coated with 10 g / m 2 Coating was continued until a tantalum loading target of 0.15 was reached.

[0052] A fluororesin protective layer is formed on the surface coating, and the loading amount of the fluororesin is 2g / m 2 An isopropanol solution containing 5 wt% Nafion was prepared. This solution was applied to the surface of the surface coating with a brush. After applying 1 g of fluororesin per square meter of coating, the object was cured, then removed to cool, and 2 g / m 2 Coating was continued until a fluororesin loading of 0.05g was reached.

[0053] In this way, the electrodes were fabricated.

[0054] Example 2 The same metal titanium (Ti) as in Example 1 was used as the electrode substrate.

[0055] The same steps as in Example 1 were used to form an Ir-Ta MMO catalyst layer on the substrate, with an Ir loading of 5 g / m 2 It was.

[0056] The same steps as in Example 1 were used to form a fluororesin protective layer on the catalyst layer, with a loading of 5 g / m 2 It was.

[0057] In this way, the electrodes were fabricated.

[0058] Example 3 The same metal titanium (Ti) as in Example 1 was used as the electrode substrate.

[0059] The same steps as in Example 1 were used to form an Ir-Ta MMO catalyst layer on the substrate, with an Ir loading of 5 g / m 2 It was.

[0060] The same steps as in Example 1 were used to form a Ta2O5 surface coating on the catalyst layer, with a Ta loading of 1 g / m 2 It was.

[0061] The same steps as in Example 1 were used to form a second Ir-Ta MMO catalyst layer on the surface coating, with an Ir loading of 1 g / m 2 It was.

[0062] The same steps as in Example 1 were used to form a second Ta2O5 surface coating on the second catalyst layer, with a Ta loading of 10 g / m 2 It was.

[0063] The same steps as in Example 1 were used to form a fluororesin protective layer on the second surface coating, with a loading of 5 g / m 2 It was.

[0064] In this way, the electrodes were fabricated.

[0065] Comparative Example 1 The same metal titanium (Ti) as in Example 1 was used as the electrode substrate.

[0066] The same steps as in Example 1 were used to form an Ir-Ta MMO catalyst layer on the substrate, with an Ir loading of 5 g / m 2 It was.

[0067] In this way, the electrodes were fabricated.

[0068] Comparative Example 2 The same metal titanium (Ti) as in Example 1 was used as the electrode substrate.

[0069] The same steps as in Example 1 were used to form an Ir-Ta MMO catalyst layer on the substrate, with an Ir loading of 5 g / m 2 It was.

[0070] The same steps as in Example 1 were used to form a Ta2O5 surface coating on the catalyst layer, with a Ta loading of 10 g / m 2 It was.

[0071] In this way, the electrodes were fabricated.

[0072] Electrode microstructure The electrode prepared in Example 1 was examined by scanning electron microscopy.

[0073] The electrode substrate is shown in FIG. 1 and is in the form of a grid.

[0074] The protective layer of the electrode is shown in Figure 2. As can be seen from Figure 2, the protective layer has a dense structure. The dense protective layer effectively prevents contact between additive molecules and the metal active sites, making it chemically inert during the oxygen generation process and significantly reducing the additive consumption rate.

[0075] Additive consumption rate testing The electrodes obtained in the examples and comparative examples were tested for additive consumption rate, and the test results are shown in Table 1.

[0076] [Table 1]

[0077] NOTE: "EVF-B" is an additive used in continuous copper plating in the production of printed circuit boards.

[0078] As can be seen from Table 1, the additive consumption rates of the electrodes (having a fluororesin protective layer) in Examples 1 to 3 of the present application are lower than the additive consumption rates of the electrodes (without a fluororesin protective layer) in Comparative Examples 1 and 2. In particular, the additive consumption rate in Example 3 is only 78 mL / KAh, which is about one-tenth of the additive consumption rate in Comparative Example 1. The main reason for this is that the fluororesin has a high density, which can effectively prevent contact between additive molecules and Ir active sites, and is chemically inert in the oxygen generation process.

[0079] In addition, in Example 2 of the present application, the additive consumption rate can still be effectively reduced even when there is no surface coating and only the fluororesin protective layer is included, which shows that the fluororesin protective layer is an important factor in reducing the additive consumption rate.

[0080] Furthermore, even though the loading amount of fluororesin in Example 1 is less than that in Example 2, the additive consumption rate in Example 1 is still lower than that in Example 2. The main reason is that the combination of Ta2O5 in the surface coating and the fluororesin in the protective layer produces a synergistic effect, and they can be better bonded, which is more favorable for reducing the additive consumption rate.

[0081] As can be further seen from Table 1, the additive consumption rate in Example 3 is even lower, indicating that the alternating stacking of MMO layers and surface coatings can achieve a better effect by reducing the additive consumption rate.

[0082] Although the embodiments disclosed in the present application are as described above, the contents described are merely embodiments adopted for the convenience of understanding the present application and are not used to limit the present application. Those skilled in the art to which the present application pertains may make any modifications and changes to the implementation methods and details without departing from the spirit and scope disclosed by the present application, but the scope of patent protection of the present application shall be as defined by the scope of the appended claims.

Claims

1. An electrode comprising a substrate, a catalyst layer, and a protective layer, the catalyst layer is selected from a mixed metal oxide layer; The protective layer is selected from an organic ionomer layer, preferably a fluororesin layer, and more preferably a sulfonated tetrafluoroethylene layer. electrode.

2. The catalyst further comprises a surface coating between the catalyst layer and the protective layer, the surface coating being a Ta oxide layer, preferably a Ta ２ O ５ selected from the layers, 10. The electrode of claim 1.

3. The method further comprises providing an intermediate layer between the substrate and the catalyst layer, the intermediate layer being selected from a Ta oxide layer, a Ti oxide layer, a Ti-Ta mixed metal oxide layer, a Ti-Ta alloy layer, or a Ti-Pd alloy layer.

3. The electrode according to claim 1 or 2.

4. The catalyst layer and the surface coating are a plurality of alternating layers.

4. An electrode according to any one of claims 1 to 3.

5. The loading amount of the protective layer is 1 g / m ２ ~10g / m ２ , preferably 2 g / m ２ ~5g / m ２ That is, 4. An electrode according to any one of claims 1 to 3.

6. The Ta content in the surface coating is 1 g / m ２ ~20g / m ２ , preferably 10 g / m ２ ~15g / m ２ That is, 6. An electrode according to any one of claims 2 to 5.

7. the catalyst layer is selected from a Ru—Ti mixed metal oxide layer, an Ir—Ti mixed metal oxide layer, a Ru—Ir—Ti mixed metal oxide layer, a Ru—Ta mixed metal oxide layer, an Ir—Ta mixed metal oxide layer, a Ru—Ir—Ta mixed metal oxide layer, or a Pt—Ir mixed metal oxide layer; 7. An electrode according to any one of claims 1 to 6.

8. the content of Ti, Ta, or Pt in the catalyst layer is 10 wt % to 80 wt %, preferably 20 wt % to 70 wt %, of the total mass of the metal elements; 8. The electrode of claim 7.

9. The loading amount of Ru, Ir, or Pt in the catalyst layer is 2 g / m ２ ~20g / m ２ , preferably 5 g / m ２ ~10g / m ２ , more preferably 6 g / m ２ ~8g / m ２ That is, 9. The electrode according to claim 7 or 8.

10. the Ta content in the Ti-Ta mixed metal oxide layer of the intermediate layer is 10 wt % or more, preferably 20 wt % or more, and more preferably 40 wt % to 50 wt % of the total mass of the metal elements; the Ta content in the Ti—Ta alloy layer of the intermediate layer is 10 wt % or more, preferably 20 wt % or more, more preferably 40 wt % to 50 wt % of the total mass of the alloy; The Pd content in the Ti-Pd alloy of the intermediate layer is 0.01 wt% to 0.25 wt%, preferably 0.12 wt% to 0.25 wt%, of the total mass of the alloy.

10. An electrode according to any one of claims 3 to 9.

11. The Ta loading amount in the intermediate Ta oxide layer, the intermediate Ti-Ta mixed metal oxide layer, and the intermediate Ti-Ta alloy layer is 1 g / m ２ ~10g / m ２ , preferably 4 g / m ２ or 5 g / m ２ and The loading amount of Ti in the Ti oxide layer of the intermediate layer and the Ti—Pd alloy layer of the intermediate layer is 1 g / m ２ ~10g / m ２ , preferably 4 g / m ２ or 5 g / m ２ That is, 11. An electrode according to any one of claims 3 to 10.

12. the substrate is selected from the metals Ti, Ta, Nb, or alloys thereof; 12. An electrode according to any one of claims 1 to 11.

13. The electrode is used as an anode for surface treatment applications, preferably as a plating anode, more preferably as a copper plating anode or a vertical conveyor plating anode. Use of an electrode according to any one of claims 1 to 12.

14. The plating is used to make printed circuit boards.

14. The use according to claim 13.

Images