Method for making protective layer for printed full-area internal electrode of multilayer ceramic capacitor end electrode

Abstract

A method for manufacturing a multi-layer ceramic capacitor (MLCC) end electrode and printing a full-area inner electrode protective layer is disclosed. The method uses thin dielectric ceramic layer thickness and a plurality of nickel inner electrode stacks to achieve high capacitance. The method produces high-density electrode-to-ceramic ratio end edges and side edges. The method uses an ultralow-temperature electrochemical deposition coating technology to manufacture a low-stress multi-layer ceramic capacitor end electrode and an insulating protective layer, thereby improving the yield of the multi-layer ceramic capacitor and reducing manufacturing costs.

Description

Technical Field

[0001] This invention relates to a method for fabricating terminal electrodes and printing a full-area inner electrode protective layer for multilayer ceramic capacitors, particularly a method for fabricating low-stress terminal electrodes and insulating protective layers for multilayer ceramic capacitors using ultra-low temperature electrochemical deposition coating technology, which can improve the yield of multilayer ceramic capacitors and reduce manufacturing costs. Background Technology

[0002] like Figure 12 As shown, this is the structure of the low-density nickel internal electrode on the end and side. Table 1 shows the manufacturing principle and method of the terminal electrode of the conventional low-nickel density multilayer ceramic capacitor (MLCC). It explains that the terminal electrode of the current general multilayer ceramic capacitor 5 is manufactured by using a thick film copper paste containing glass, using an immersion plating process to form the terminal electrode, and then using high temperature (800-900℃) under nitrogen atmosphere protection to heat treat and sinter to form copper terminal electrode 53. The copper and nickel internal electrode 52 form an alloy ohmic contact to connect the internal electrode 52 in parallel to achieve the purpose of low loss and high capacitance. The glass in the copper paste is used to connect the dielectric ceramic body 51 and the copper terminal electrode 53.

[0003] Table 1. Principles and methods of traditional MLCC terminal electrode fabrication

[0004]

[0005] As shown in Table 1, the existing technology uses thick-film conductive copper paste, which is formed through an dip-plating process, and then heat-treated at 750-900°C in a nitrogen reducing atmosphere for about 1 hour to sinter the copper terminal electrodes of the multilayer ceramic capacitor. However, this high-temperature reducing atmosphere terminal electrode process for multilayer ceramic capacitors causes high internal stress release due to the high-temperature heat treatment, resulting in component cracks and serious defects.

[0006] Furthermore, when manufacturing a multilayer ceramic capacitor 5 with a high capacitance value, in addition to reducing the thickness of the dielectric ceramic layer 51 between adjacent inner electrodes 52, it is also necessary to stack more layers of inner electrodes 52. This easily leads to a much higher density of electrodes in the middle compared to a density with only dielectric ceramic layers 51 on both sides. Further high-temperature sintering can easily result in the so-called "bread effect," such as... Figure 13As shown, this multilayer ceramic capacitor has bread-like protrusions at the top and bottom. Regarding the aforementioned solution to the significant density difference between the electrode-containing portion and the electrode-free portion on the sides caused by the thin dielectric layer and multiple internal electrode stacks in the fabrication of high-capacitance multilayer ceramic capacitors, existing technologies involve printing ceramic material on the electrode-free portions on both sides to reduce the density. Another approach is to additionally fabricate high-temperature ceramic insulating protective layers on both sides. This requires additional printing of the ceramic insulating layer, followed by sintering under an ultra-high temperature reducing atmosphere to ensure a tight bond between the multilayer ceramic capacitor and the protective layer; thereby, these methods supplement the thickness of the nickel internal electrode layer. However, this process of additionally fabricating high-temperature ceramic insulating protective layers in multilayer ceramic capacitors results in high internal stress release due to high-temperature heat treatment, leading to component cracks and serious defects.

[0007] Given that current multilayer ceramic capacitor (MLC) electrode fabrication processes involve high-temperature reducing atmosphere sintering, and that the density difference between the densely stacked electrodes in the center and the blank ceramic layers on the sides after sintering causes a "bread effect," addressing the internal stress quality issues in high-capacitance MLC capacitors presents a significant challenge. Therefore, the development of ultra-low temperature electrode technology is urgently needed. Consequently, current methods generally cannot meet the practical needs of users. Summary of the Invention

[0008] The main objective of this invention is to overcome the aforementioned problems encountered by known technologies and to provide a method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor. The method uses ultra-low temperature electrochemical deposition coating technology to fabricate low-stress multilayer ceramic capacitor terminal electrodes and insulating protective layers, which can improve the yield of multilayer ceramic capacitors and reduce manufacturing costs.

[0009] To achieve the above objectives, the technical solution adopted by the present invention is: a method for fabricating end electrodes and a printed full-area inner electrode protective layer of a multilayer ceramic capacitor, the method comprising at least the following steps: Step A: providing a multilayer ceramic capacitor without end electrodes after sintering, the multilayer ceramic capacitor being formed by alternating stacking of several thin dielectric ceramic layers and several inner electrodes, and the inner electrodes of the multilayer ceramic capacitor being printed over the entire area, so that the end edges of the multilayer ceramic capacitor have high-density inner electrodes; Step B: using a wet chemical immersion deposition method, immersing the multilayer ceramic capacitor in a metal solution at a temperature less than 80°C, initially undergoing electrochemical deposition, a metal film slowly grows on the surface of the inner electrode; and Step C: after deposition for 1 to 2 hours, the metal film growing on the surface of the inner electrode continues to grow and connects together, so that the end edges of the multilayer ceramic capacitor form a metal-plated end electrode with a connecting surface.

[0010] In the above embodiments of the present invention, the wet chemical immersion coating is achieved using general metal electroplating or metal chemical plating with metal displacement chemical plating.

[0011] In the above embodiments of the present invention, the ratio of the internal electrode to the dielectric ceramic layer of the multilayer ceramic capacitor is greater than 1:50.

[0012] In the above embodiments of the present invention, the material of the electrochemically deposited metal coating end electrode is the same metal material as the inner electrode, or a material that forms an alloy metal with the inner electrode and can be used as an ohmic contact.

[0013] In the above embodiments of the present invention, the metal-coated end electrode is a copper end electrode, a nickel end electrode, a copper-nickel alloy end electrode, a copper-manganese-nickel alloy end electrode, or a nickel-chromium-silicon alloy end electrode.

[0014] In the above embodiments of the present invention, the metal solution is copper sulfate, nickel sulfate, manganese sulfate, chromium sulfate, silicon compound or a combination thereof.

[0015] In the above embodiments of the present invention, the method further includes the following step D: using a low-temperature heat treatment of 200-300°C to oxidize the metal-plated end electrodes on both sides of the multilayer ceramic capacitor into metal oxides as an insulating protective layer.

[0016] In the above embodiments of the present invention, the bonding force between the metal-coated end electrode and the dielectric ceramic layer includes the bonding force between the metal-coated end electrode and the dielectric ceramic layer, and the bonding force between the inner electrode and the metal-coated end electrode.

[0017] The present invention also provides a method for fabricating the terminal electrodes of a multilayer ceramic capacitor and printing a full-area inner electrode protective layer. The method includes at least the following steps: Step A1: providing a multilayer ceramic capacitor without terminal electrodes after sintering, the multilayer ceramic capacitor being formed by alternating stacking of several thin dielectric ceramic layers and several inner electrodes, and the inner electrodes of the multilayer ceramic capacitor being printed over the entire area, so that the terminal edge of the multilayer ceramic capacitor has a high density of inner electrodes; Step B1: immersing the multilayer ceramic capacitor in a metal solution at a low temperature and baking it, and then fabricating an aluminum terminal electrode on the surface of the inner electrode after heat treatment at less than 200°C; and Step C1: using a wet chemical immersion coating method, immersing the multilayer ceramic capacitor with the aluminum terminal electrode in a metal solution at 60-80°C for 10-60 minutes, after which the aluminum terminal electrode of the multilayer ceramic capacitor undergoes a chemical oxidation-reduction replacement reaction, transforming into a metal-plated terminal electrode corresponding to the metal solution. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the high-density nickel internal electrode at the end and side of the present invention.

[0019] Figure 2 This is a schematic diagram comparing the reduction potential of the high-capacitance, high-internal-nickel-electrode-density multilayer ceramic capacitor of the present invention with that of a conventional low-nickel internal-electrode multilayer ceramic capacitor.

[0020] Wherein, a- the reduction potential of the high capacitance, high nickel internal electrode density multilayer ceramic capacitor of the present invention, and b- the reduction potential of the conventional low nickel internal electrode density multilayer ceramic capacitor.

[0021] Figure 3 This is a schematic diagram comparing the innovative terminal electrode fabrication process of this invention with the current terminal electrode fabrication process of multilayer ceramic capacitors.

[0022] Figure 4 This is a schematic diagram showing the replacement of the high-density nickel electrode on the side of the high-capacitance multilayer ceramic capacitor of the present invention with a copper end electrode.

[0023] Among them, a- has a high density of nickel internal electrodes, b- copper electrodes are gradually formed on the surface of the nickel internal electrodes, and c- the copper electrodes on the surface of the nickel internal electrodes form copper end electrodes.

[0024] Figure 5 This is an optical microstructure diagram of the copper end electrode after electroplating deposition according to the present invention.

[0025] Figure 6 These are electron microstructure and material analysis diagrams of the copper end electrode in the electroplating deposition process of this invention.

[0026] Among them, a-electron microstructure of copper end electrode in electroplating deposition, b-material analysis of copper end electrode, and c-material analysis of nickel internal electrode.

[0027] Figure 7 This is a schematic diagram of the high-capacitance multilayer ceramic capacitor of the present invention being converted into copper-terminal electrodes after being immersed in a low-temperature copper sulfate solution.

[0028] Figure 8 This is an optical microstructure diagram of the high-capacitance multilayer ceramic capacitor of the present invention, which is immersed in a low-temperature copper sulfate solution for 20 minutes to 2 hours, showing the gradual transformation of the terminal electrode into a copper terminal electrode.

[0029] Figure 9 This is a schematic diagram of how the low-temperature aluminum end electrode of the multilayer ceramic capacitor of the present invention is transformed into a copper end electrode by a redox chemical displacement reaction.

[0030] Figure 10 This is a schematic diagram of the present invention, showing the printing of full-area electrodes and the fabrication of protective insulating layers on both sides.

[0031] Figure 11 This is an optical microstructure image of the multilayer ceramic capacitor with high capacitance value that is fully printed and free of breading effect, produced by this invention.

[0032] In the figure, a and b are copper electrodes that grow out from both sides of the multilayer ceramic component. The arrow in b points to the copper electrode. c is the copper electrode oxidized into copper oxide insulating protective layer in the upper and lower figures.

[0033] Figure 12 This is a schematic diagram of a low-density nickel internal electrode with known end and side edges.

[0034] Figure 13 This is a schematic diagram illustrating the bulging bread effect caused by the sintering of a known high-capacitance multilayer ceramic capacitor.

[0035] Numbering Reference:

[0036] Multilayer ceramic capacitor 1

[0037] Dielectric ceramic layer 11

[0038] Internal electrode 12

[0039] Copper electrode 13a

[0040] Copper end electrode 13

[0041] Copper sulfate solution 2

[0042] Multilayer ceramic capacitor 3

[0043] Aluminum end electrode 31

[0044] Copper end electrode 32

[0045] Multilayer ceramic capacitor 4

[0046] Dielectric ceramic layer 41

[0047] Internal electrode 42

[0048] Insulating protective layer 43

[0049] Dashed line A

[0050] Multilayer ceramic capacitor 5

[0051] Dielectric ceramic layer 51

[0052] Internal electrode 52

[0053] Copper end electrode 53. Detailed Implementation

[0054] Please see Figures 1 to 11The figures shown are as follows: a schematic diagram of the high-density nickel internal electrode on the end and side of the present invention; a schematic diagram comparing the reduction potential of the high-capacitance, high-internal-nickel electrode density multilayer ceramic capacitor of the present invention with that of a conventional low-nickel internal electrode multilayer ceramic capacitor; a schematic diagram comparing the innovative end electrode process of the present invention with the current end electrode process of multilayer ceramic capacitors; a schematic diagram of replacing the high-density nickel electrode on the side of the high-capacitance multilayer ceramic capacitor of the present invention with a copper end electrode; an optical microstructure diagram of the copper end electrode after electroplating deposition of the present invention; an electron microstructure and material analysis diagram of the copper end electrode during electroplating deposition of the present invention; a schematic diagram of the high-capacitance multilayer ceramic capacitor of the present invention being converted into a copper end electrode after being immersed in a low-temperature copper sulfate solution; an optical microstructure diagram of the high-capacitance multilayer ceramic capacitor of the present invention being gradually converted into a copper end electrode after being immersed in a low-temperature copper sulfate solution for 20 minutes to 2 hours; a schematic diagram of the low-temperature aluminum end electrode of the multilayer ceramic capacitor of the present invention being converted into a copper end electrode using a redox chemical substitution reaction; a schematic diagram of the present invention printing a full-area electrode and then fabricating protective insulating layers on both sides; and an optical microstructure diagram of the high-capacitance multilayer ceramic capacitor fabricated with full-area printing and no breading effect. As shown in the figure: This invention relates to a method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer for multilayer ceramic capacitors (MLCCs). It utilizes a thin dielectric ceramic layer 11 and stacked multiple layers of nickel inner electrodes 12 to achieve high capacitance, thus creating a high-density electrode-to-ceramic ratio at the terminal and side edges. Figure 1 As shown.

[0055] Figure 2 The reduction potential diagrams of the multilayer ceramic capacitor produced by this invention and the conventional multilayer ceramic capacitor were measured by cyclic voltammetry. It is obvious that the multilayer ceramic capacitor with improved capacitance value of this invention has a higher reduction potential because it has a higher internal nickel electrode density that is biased towards conductors. This means that electrochemical deposition coating can be easily performed on this end face or side face.

[0056] Table 2 illustrates the manufacturing principle and method of the terminal electrode of the high-capacitance, high-nickel internal electrode density multilayer ceramic capacitor of the present invention. Since the high-capacitance multilayer ceramic capacitor has a high-density nickel internal electrode with a high reduction potential at its end edge, the terminal electrode can be fabricated using electrochemical deposition technology, including electroplating and electroless plating. The electrochemically deposited metal film terminal electrode and material can be the same material as the nickel internal electrode, or a material that can form an ohmic contact with the nickel internal electrode. The bonding force between the terminal electrode and the dielectric ceramic layer includes not only the bonding force between the electrochemically deposited metal film terminal electrode and the dielectric ceramic layer, but also the bonding force between the high-density nickel internal electrode of the multilayer ceramic capacitor and the electrochemically deposited metal film terminal electrode.

[0057] Table 2. Principle and method of MLCC terminal electrode fabrication process of the present invention

[0058]

[0059] A comparison diagram of the fabrication processes for the terminal electrodes of traditional and innovative multilayer ceramic capacitors is shown below. Figure 3 As shown, the traditional process uses thick-film copper paste for dip-plating to form the copper terminal electrode, which is then sintered under high-temperature nitrogen to form the copper terminal electrode, as enclosed by the dashed line A in the figure. The innovative process proposed in this invention uses electrochemical deposition to obtain the copper terminal electrode 13, replacing the portion enclosed by the dashed line A.

[0060] The above-mentioned process for obtaining copper end electrodes by electrochemical deposition is as follows: Figure 4 As shown, and Figure 4 a is a high-capacitance multilayer ceramic capacitor with a high-density nickel internal electrode 12 at its end face. Initially, through electrochemical deposition, a copper electrode 13a slowly forms on the surface of the nickel internal electrode 12, such as... Figure 4 As shown in b. After a period of deposition, the copper electrodes 13a growing on the surface of the nickel inner electrode 12 continue to grow and connect together, forming a copper end electrode 13 at one end, as shown in b. Figure 4 As shown in c. The optical microstructure of the copper end electrode 13 after electroplating deposition according to the present invention is as follows. Figure 5 The image shows the complete structure as seen under an optical microscope. Figure 4 c. Electrochemically deposited copper end electrode. The electron microstructure of the copper end electrode in electroplating deposition is as follows: Figure 6 Figure a shows an electron microscope image of the microstructure of the innovative copper electrode and nickel internal electrode; its material analysis is as follows. Figure 6 Figures b and 6c show the material analysis of the copper end electrode and the nickel internal electrode, respectively. It is clear from these figures that the copper end electrode and the nickel internal electrode have a good connection.

[0061] The following examples are provided only to illustrate the details and implications of the present invention, and are not intended to limit the scope of the patent application of the present invention.

[0062] Implementation Method 1: Terminal Electrodes of Multilayer Ceramic Capacitor (I)

[0063] This innovative process does not use copper paste and a high-temperature nitrogen furnace for sintering. Instead, it immerses the multilayer ceramic capacitor 1, which has no terminal electrodes after sintering, in a copper sulfate solution 2 at 80°C. Figure 7 As shown, a copper electrode 13a first gradually grows on the upper end of the nickel inner electrode 12. As time progresses, the copper electrodes 13a and 13a become increasingly closer together, and after about one hour, the copper end electrode 13 of the connection surface is formed. (See diagram below.) Figure 8As shown in Table 3, when a high-capacitance multilayer ceramic capacitor is immersed in a copper sulfate solution at 80°C, the formation of the side copper terminal electrodes of the multilayer ceramic capacitor becomes more and more complete as the immersion time in the copper sulfate solution increases from 20 minutes to 2 hours. As shown in Table 3, the longer the immersion time, the more complete the copper terminal electrode formation, and the change in its dielectric properties becomes more and more similar to the characteristics of copper terminal electrodes sintered at high temperature under nitrogen using thick film copper paste.

[0064] Table 3. Changes in the terminal electrodes of multilayer ceramic capacitors immersed in copper sulfate solution at 80℃.

[0065]

[0066]

[0067] Implementation Method 2: Terminal Electrodes of Multilayer Ceramic Capacitors (II)

[0068] like Figure 9 As shown, the present invention involves immersing and baking the multilayer ceramic capacitor 3 at a low temperature, followed by heat treatment at a temperature below 200°C to form an aluminum terminal electrode 31 on the surface of the inner electrode. Then, using a wet chemical immersion coating method, the multilayer ceramic capacitor 3 with the aluminum terminal electrode 31 is immersed in a copper sulfate solution 2 at 60-80°C for 10-60 minutes. After the aluminum terminal electrode 31 of the multilayer ceramic capacitor 3 undergoes a chemical oxidation-reduction replacement reaction, it becomes a copper terminal electrode 32 of the multilayer ceramic capacitor. Its capacitance characteristics are comparable to those of the copper terminal electrode of the multilayer ceramic capacitor sintered under a high-temperature reducing atmosphere of nitrogen by immersion coating with copper paste.

[0069] Implementation Method 3: Insulating Protective Layer for Multilayer Ceramic Capacitors

[0070] In traditional high-capacitance multilayer ceramic capacitors, the density difference between the stacked internal electrodes 52 in the middle and the blank dielectric ceramic layers 51 on both sides after sintering causes a bulging "bread effect," such as... Figure 13 As shown. The solution proposed in this invention is to print a full-area electrode and then fabricate insulating protective layers 43 on both sides, as shown. Figure 10 As shown. This invention prints the entire area of ​​the inner electrode 42, thus eliminating density differences caused by the presence of the inner electrode 42 in the center and the absence of it on the sides. This approach not only ensures high uniformity in the internal fabrication of the multilayer ceramic capacitor 4 but also maximizes the printing area, facilitating the achievement of high capacitance values ​​through a large area. The only challenge is creating an insulating protective layer on both sides of the multilayer ceramic component.

[0071] Figure 11 This insulating protective layer, similar to the aforementioned high-capacitance copper terminal electrode, involves immersing the multilayer ceramic assembly in a copper sulfate solution at 80°C for 1 hour, allowing copper electrodes to grow on both sides. Figure 11 a, Figure 11 As shown in b, after baking in air at a low temperature of 250°C for half an hour, the copper electrodes on both sides are oxidized to form an insulating protective layer of copper oxide. Figure 11 As shown in c, this does not affect the conductivity of the nickel internal electrode. In this way, a multilayer ceramic capacitor with high capacitance and no breading effect can be fabricated with full-area printing.

[0072] Therefore, the main technical features of this invention are as follows:

[0073] 1. The ratio of the inner electrode layer to the dielectric ceramic layer in a multilayer ceramic capacitor must be greater than 1:50. This not only increases the conductivity of the dielectric ceramic side but also forms continuous end electrodes or side electrodes.

[0074] 2. This wet chemical immersion coating technology can be achieved using general metal electroplating or metal chemical plating, including metal displacement chemical plating.

[0075] 3. The chemically deposited film and the laminated ceramic inner electrode can be made of copper or an alloy metal, thus forming a good electrode connection and ohmic contact with the inner electrode.

[0076] 4. The bonding force between the metal-coated end electrode and the dielectric ceramic layer comes not only from the bonding force between the metal coating and the dielectric ceramic layer, but also from the bonding force between the inner electrode and the metal coating.

[0077] 5. The chemically immersed metal coating on this side can be transformed into a metal oxide as an insulating protective layer under appropriate heat treatment conditions.

[0078] Furthermore, the key technical features that distinguish this invention from the prior art are as follows:

[0079] 1. This innovative technology eliminates the need for thick-film conductive paste and high-temperature sintering electrodes under a protective atmosphere. It enables the fabrication of terminal electrodes for high-capacitance multilayer ceramic capacitors with ultra-low internal stress at low temperatures, suitable for thin dielectric layers and multiple internal electrodes.

[0080] 2. This innovative technology involves creating an additional insulating protective layer on both sides using a low-temperature (<300℃) heat treatment process in air. The bonding strength between this innovative process and the multilayer ceramic capacitor mainly comes from the connection between the internal electrode and the insulating protective layer. Because it is a low-temperature process, there is no need for printing processes or high-temperature reducing atmosphere heat treatment processes. The process is simple and the quality of the insulating protective layer is more optimized than that of current processes.

[0081] Therefore, this innovative technology is applicable to the passive component industry, and applicable commercial products include those that replace related precious metal electrodes with copper electrodes, such as the terminal electrodes of passive component multilayer ceramic capacitors and ultra-low resistance chip resistors.

[0082] In summary, this invention provides a method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer for multilayer ceramic capacitors. This method effectively overcomes the various shortcomings of existing technologies. By using ultra-low temperature electrochemical deposition coating technology to fabricate low-stress terminal electrodes and insulating protective layers for multilayer ceramic capacitors, the yield of multilayer ceramic capacitors can be improved and manufacturing costs reduced. Consequently, this invention is more advanced, more practical, and better meets the needs of users. It has indeed met the requirements for an invention patent application, and a patent application is hereby filed in accordance with the law.

[0083] However, the above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any simple equivalent changes and modifications made in accordance with the claims and description of the present invention should still fall within the scope of the present invention.

Claims

1. A method for fabricating terminal electrodes and printing a full-area inner electrode protective layer for a multilayer ceramic capacitor, characterized in that, This method includes at least the following steps: Step A: Provide a multilayer ceramic capacitor without end electrodes after sintering. The multilayer ceramic capacitor is formed by alternating stacking of several thin dielectric ceramic layers and several internal electrodes. The internal electrodes of the multilayer ceramic capacitor are printed over the entire area, so that the end edge of the multilayer ceramic capacitor has a high density of internal electrodes. Step B: Using a wet chemical immersion coating method, the multilayer ceramic capacitor is immersed in a metal solution at a temperature of less than 80°C. Initially, an electrochemical deposition process is performed, and a metal coating slowly grows on the surface of the inner electrode. as well as Step C: After deposition for 1 to 2 hours, the metal coating on the surface of the inner electrode continues to grow and connect together, so that the metal coating end electrode of the stacked ceramic capacitor forms the connecting surface. Step D: Use a low-temperature heat treatment of 200-300℃ to oxidize the metal-plated end electrodes on both sides of the multilayer ceramic capacitor into metal oxide as an insulating protective layer.

2. The method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor as described in claim 1, characterized in that, The wet chemical immersion coating is achieved using conventional metal electroplating or metal electroless plating.

3. The method for fabricating the terminal electrodes of a multilayer ceramic capacitor and printing a full-area inner electrode protective layer as described in claim 2, characterized in that, The metal electroless plating is a metal displacement electroless plating.

4. The method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor as described in claim 1, characterized in that, The material of the electrochemically deposited metal coating end electrode is the same metal material as the inner electrode, or a material that forms an alloy with the inner electrode and can make an ohmic contact.

5. The method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor as described in claim 1 or 4, characterized in that, The metal-coated end electrode is a copper end electrode, a nickel end electrode, a copper-nickel alloy end electrode, a copper-manganese-nickel alloy end electrode, or a nickel-chromium-silicon alloy end electrode.

6. The method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor as described in claim 1, characterized in that, The metal solution is copper sulfate, nickel sulfate, manganese sulfate, chromium sulfate, or a combination thereof; or, the metal solution is a combination containing a silicon compound and containing at least one of copper sulfate, nickel sulfate, manganese sulfate, and chromium sulfate.

7. The method for fabricating the terminal electrodes and printing a full-area inner electrode protective layer of a multilayer ceramic capacitor as described in claim 1, characterized in that, The bonding force between the metal-coated end electrode and the dielectric ceramic layer includes the bonding force between the metal-coated end electrode and the dielectric ceramic layer, and the bonding force between the inner electrode and the metal-coated end electrode.

8. A method for fabricating terminal electrodes and printing a full-area inner electrode protective layer for a multilayer ceramic capacitor, characterized in that, This method includes at least the following steps: Step A1: Provide a multilayer ceramic capacitor without end electrodes after sintering. The multilayer ceramic capacitor is formed by alternating stacking of several thin dielectric ceramic layers and several internal electrodes. The internal electrodes of the multilayer ceramic capacitor are printed over the entire area, so that the end edge of the multilayer ceramic capacitor has a high density of internal electrodes. Step B1: The multilayer ceramic capacitor is dip-plated and baked at a low temperature. After heat treatment at less than 200°C, an aluminum terminal electrode is formed on the surface of the inner electrode. as well as Step C1: Using a wet chemical immersion coating method, the multilayer ceramic capacitor with the aluminum terminal electrode is immersed in a metal solution at 60-80°C for 10-60 minutes. After the aluminum terminal electrode of the multilayer ceramic capacitor undergoes a chemical oxidation-reduction displacement reaction, it is transformed into a metal-coated terminal electrode corresponding to the metal solution.

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