Paste for external electrodes

Abstract

The present invention provides a paste for external electrodes, the paste being capable of improving the strength of a dried film. The paste for external electrodes is used for forming an external electrode of a multilayer ceramic electronic component, and comprises: an acrylic resin and an ethyl cellulose resin, which are at least partially copolymerized; a Cu powder; a glass powder; and a solvent. The ratio (SSA_Glass / SSA_Cu) of the BET specific surface area (SSA_Glass) of the glass powder to the BET specific surface area (SSA_Cu) of the Cu powder is 0.11 to 5.8 inclusive.

Description

External electrode paste

[0001] The present invention relates to a paste for external electrodes.

[0002] Significant demand is expected for multilayer ceramic capacitors (MLCCs) as electronic components for automobiles, mobile phones, and the like. In recent years, there has been a demand for smaller, larger capacitance, higher reliability, and multiple terminals in electronic components, which has led to a demand for thinner and flatter external electrodes in electronic components. However, as external electrodes become thinner, it has been reported that peeling and chipping of the external electrodes occur after the external electrode paste has been applied and dried, especially at corners where the film thickness is thin. Therefore, there is a demand for improving the strength of the external electrode paste applied to electronic components.

[0003] Patent Document 1 discloses an external electrode paste that contains a resin containing an ethyl cellulose-based resin and an acrylic-based resin, at least partially copolymerized, a Cu filler, and a solvent, and that has an interfacial tension of 15 N / m or more between the resin and the solvent. This external electrode paste has sufficient strength to form a dry film.

[0004] Japanese Patent Application Laid-Open No. 2021-77750

[0005] In Patent Document 1, the strength of the dried film is improved by adjusting the interfacial tension between the resin and the solvent, but there is also a need to develop a paste for external electrodes that can improve the strength of the dried film by a different method.

[0006] SUMMARY OF THE INVENTION Therefore, a primary object of the present invention is to provide an external electrode paste that can improve the strength of the dried film and is used to form external electrodes of multilayer ceramic electronic components.

[0007] The external electrode paste used to form external electrodes of the multilayer ceramic electronic component according to the present invention contains an acrylic resin and an ethyl cellulose resin, at least a portion of which are copolymerized, Cu powder, glass powder, and a solvent, and the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less.

[0008] In the external electrode paste, at least a portion of the acrylic resin and the ethyl cellulose resin are copolymerized. Therefore, the dried film obtained by applying this external electrode paste to an electronic component body has the flexibility, or toughness, inherent to the acrylic resin and the rigidity inherent to the ethyl cellulose resin, thereby improving the strength of the dried film. Furthermore, the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less. Therefore, chipping, peeling, and the like can be suppressed in the dried film after the external electrode paste is applied to an electronic component body and dried, further improving the strength of the dried film. Furthermore, when the external electrode paste is applied to a laminate, the external electrode paste can be prevented from becoming bulged at the end face of the laminate. Therefore, the dried film can be formed flat over substantially the entire end face of the laminate. As described above, by using the external electrode paste, it is possible to improve the strength of the dry film while flattening the dry film, which makes it possible to miniaturize the electronic component while suppressing a decrease in strength even when the dry film is flattened and thinned.

[0009] According to the present invention, it is possible to provide an external electrode paste that can be used to form external electrodes of a multilayer ceramic electronic component, and that can improve the strength of the dried film.

[0010] The above and other objects, features, and advantages of the present invention will become more apparent from the following detailed description of the preferred embodiments of the present invention, which proceeds with reference to the accompanying drawings.

[0011] 1 is a perspective view showing an example of a multilayer ceramic capacitor as an electronic component according to an embodiment of the present invention; 2 is a cross-sectional view taken along line II-II in FIG. 1; 3 is a diagram illustrating a step of applying an external electrode paste according to the present embodiment to a laminate; 4(a) is a diagram schematically illustrating an LW cross section of a multilayer ceramic capacitor in which external electrodes are formed on a laminate using the external electrode paste according to the present embodiment, and 4(b) is a diagram schematically illustrating an LW cross section of a multilayer ceramic capacitor in which external electrodes are formed on a laminate using a conventional external electrode paste.

[0012] 1. Embodiments An external electrode paste according to an embodiment of the present invention is used to form external electrodes of a multilayer ceramic electronic component. The external electrode paste includes an acrylic resin and an ethyl cellulose resin, at least a portion of which are copolymerized, a Cu powder, a glass powder, and a solvent. Furthermore, the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less.

[0013] The acrylic resin is, for example, at least one of isobutyl methacrylate, methyl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate.

[0014] The ethyl cellulose-based resin is, for example, at least one of ethyl cellulose, methyl cellulose, hydroxypropyl cellulose, trityl cellulose, acetyl cellulose, carboxymethyl cellulose, and nitrocellulose.

[0015] The Cu powder is particles made of at least one of Cu and a Cu alloy.

[0016] The glass powder is not particularly limited, but from the viewpoint of promoting the adsorption of Cu powder to the glass powder, it preferably contains B or Bi, and examples thereof include Bi-B-Si-O and Bi-B-Al-Si-O systems. The glass powder may also contain a borosilicate glass composition. A borosilicate glass composition is a glass composition that contains B oxide and Si oxide as network-forming oxides and alkali metal element oxides and alkaline earth metal element oxides as modifying oxides.

[0017] The solvent may include, for example, at least one of terpineol, dihydroterpineol, dihydroterpinyl acetate, propylene glycol phenyl ether, benzyl alcohol, texanol, and butyl carbitol acetate. The solvent species can be analyzed by measuring the evolved gas using gas chromatography-mass spectrometry. Gas chromatography-mass spectrometry can be performed using, for example, a mass spectrometer 7890A / 5975C (heated to 500°C) manufactured by Agilent Technologies, Inc.

[0018] In addition, the external electrode paste may contain various additives such as a dispersant, a plasticizer, an anti-settling agent, and a thixotropic agent.

[0019] The external electrode paste is produced by weighing and mixing at least a partially copolymerized acrylic resin and ethyl cellulose resin, Cu powder, glass powder, and a solvent in a predetermined mixing ratio, and dispersing and kneading the mixture using a three-roll mill or the like.

[0020] As described above, the acrylic resin and the ethyl cellulose resin are at least partially copolymerized. For example, the OH group of the ethyl cellulose resin is substituted with a vinyl group, and the ethyl cellulose resin and the acrylic resin are bonded via the substituted vinyl group.

[0021] When forming external electrodes using an external electrode paste containing Cu powder, baking must be performed at a low oxygen partial pressure in order to prevent blister defects and to prevent oxidation of Cu. That is, it is preferable to use a resin that decomposes even in the presence of little oxygen as a binder, and it is preferable to use a resin that contains a large amount of acrylic resin as such a resin.

[0022] However, if an external electrode paste containing only an ethyl cellulose resin and an acrylic resin without copolymerization is used, the dried film will be brittle. Therefore, electronic components coated with such an external electrode paste may suffer from chipping or peeling of the dried film during transport. This is thought to be due to the following reasons.

[0023] A dried film obtained by applying an external electrode paste containing a resin in which an acrylic resin and an ethyl cellulose resin are at least partially copolymerized to the body of an electronic component has flexibility, in other words, toughness, derived from the acrylic resin, and rigidity derived from the ethyl cellulose resin, and has sufficient strength as a dried film.

[0024] In contrast, in the case of an external electrode paste containing a non-copolymerized acrylic resin and an ethyl cellulose resin, phase separation between the acrylic resin and the ethyl cellulose resin is promoted during the kneading step with Cu powder during the manufacturing process, resulting in segregation of glass powder in the external electrode paste. When an external force is applied to the dried film obtained by applying this external electrode paste to the body of an electronic component, cracks tend to propagate from brittle points such as the interface between the glass segregation and Cu, which is thought to cause chipping or peeling. Chip and peeling of the external electrodes of electronic components can be detected by observing their appearance with an optical microscope.

[0025] Furthermore, in the external electrode paste according to this embodiment, the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less. This allows the Cu powder and glass powder to be densely packed within the external electrode paste due to convection during drying of the external electrode paste. This reduces the void ratio in the dried film, thereby improving the strength of the dried film. Note that if the void ratio in the dried film is large, cracks are likely to develop from the voids when the dried film is subjected to an impact. However, with the external electrode paste having the above configuration, the void ratio can be reduced, thereby suppressing crack development and improving the strength of the dried film.

[0026] The BET specific surface area of ​​the target substance (Cu powder or glass powder) can be measured by a method in which gas molecules with a known adsorption area are adsorbed onto the surface of the target substance and the specific surface area of ​​the target substance is measured from the amount of adsorption of the gas molecules. The BET specific surface area was measured using an MR-6 (manufactured by Microtrac Bell) as a BET specific surface area evaluation device, and after degassing at 150°C for 20 minutes, the measurement was performed using the BET single-point method.

[0027] Next, a process for applying the external electrode paste to the laminate in this embodiment will be described. Fig. 1 is an external perspective view showing an example of a multilayer ceramic capacitor as an electronic component according to an embodiment of the present invention. Fig. 2 is a cross-sectional view taken along line II-II in Fig. 1. Fig. 3 is a view for explaining the process for applying the external electrode paste to the laminate in this embodiment.

[0028] First, a multilayer ceramic capacitor formed by applying an external electrode paste will be described. As shown in Figures 1 and 2, the multilayer ceramic capacitor 10 includes a rectangular parallelepiped laminate 12 having internal electrode layers 16 therein, and external electrodes 30 disposed on both ends of the laminate 12.

[0029] The laminate 12 has a first main surface 12a and a second main surface 12b that face each other in a height direction x (stacking direction), a first side surface 12c and a second side surface 12d that face each other in a width direction y that is perpendicular to the height direction x, and a first end surface 12e and a second end surface 12f that face each other in a length direction z that is perpendicular to the height direction x and the width direction y.

[0030] The laminate 12 includes a plurality of ceramic layers 14. The plurality of ceramic layers 14 are stacked in a height direction x. The dielectric material forming the ceramic layers 14 may be, for example, a dielectric ceramic containing a component such as BaTiO, CaTiO, SrTiO, or CaZrO.

[0031] When a piezoelectric ceramic material is used for the ceramic layer 14, the electronic component functions as a piezoelectric component. Specific examples of piezoelectric ceramic materials include PZT (lead zirconate titanate) ceramic materials. When a semiconductor ceramic material is used for the ceramic layer 14, the electronic component functions as a thermistor element. Specific examples of semiconductor ceramic materials include spinel ceramic materials. When a magnetic ceramic material is used for the ceramic layer 14, the electronic component functions as an inductor element. When functioning as an inductor element, the internal electrode layer 16 becomes a coil-shaped conductor. Specific examples of magnetic ceramic materials include ferrite ceramic materials.

[0032] The laminate 12 has a plurality of first internal electrode layers 16a extending to the first end face 12e and a plurality of second internal electrode layers 16b extending to the second end face 12f as the plurality of internal electrode layers 16. The plurality of first internal electrode layers 16a and the plurality of second internal electrode layers 16b are embedded so as to be alternately arranged at equal intervals with the ceramic layers 14 sandwiched between them along the height direction x of the laminate 12.

[0033] As shown in FIGS. 1 and 2, external electrodes 30 are disposed on the first end face 12e side and the second end face 12f side of the laminate 12.

[0034] The external electrode 30 includes a first external electrode 30a and a second external electrode 30b.

[0035] The first external electrode 30a is disposed on at least the surface of the first end face 12e and is connected to the first internal electrode layer 16a. In this embodiment, the first external electrode 30a extends from the first end face 12e and is disposed on a part of the first main face 12a, a part of the second main face 12b, a part of the first side face 12c, and a part of the second side face 12d.

[0036] The second external electrode 30b is disposed on at least the surface of the second end face 12f and is connected to the second internal electrode layer 16b. In this embodiment, the second external electrode 30b extends from the second end face 12f and is disposed on a part of the first main face 12a, a part of the second main face 12b, a part of the first side face 12c, and a part of the second side face 12d.

[0037] When forming external electrodes 30 on such a multilayer ceramic capacitor 10, the regions of the laminate 12 where the external electrodes 30 are to be formed are immersed in external electrode paste 31 (see FIG. 3( a)) and then pulled up (see FIG. 3( b)). The regions where the external electrodes 30 are to be formed are, for example, both end faces (first end face 12 e) and second end face 12 f) of the laminate 12. Here, the external electrode paste attached to the laminate 12 is denoted by the reference symbol 31 a in the following description. When the laminate 12 is pulled up, Marangoni convection occurs as indicated by the arrows in FIG. 3( b) due to temperature differences and solute concentration differences between the center and end portions of the external electrode paste 31 a attached to the laminate 12. The solutes are Cu powder, glass powder, and resin contained in the external electrode paste.

[0038] Because the amount of external electrode paste applied is smaller at the edges than at the center, drying proceeds more quickly at the edges. Therefore, the proportion of resin in the external electrode paste is higher at the edges than at the center, making it energetically unstable, resulting in an outward flow of the external electrode paste from the center to the edges (see FIG. 3( c)). This outward flow occurs as long as the resin concentration at the edges is higher than that at the center. It is believed that as drying proceeds, the number of interfaces between the solute and the solvent increases, making it energetically unstable and strengthening the outward flow.

[0039] Here, the ethyl cellulose resin has rigidity and high heat storage capacity, and therefore prevents the external electrode paste from solidifying during flow in the drying process and plays a role in promoting outward flow. The generation of a strong outward flow causes the external electrode paste to flow from the center to the edges, making it possible to prevent the external electrode paste from bulging outward in the center (see FIG. 3(d)).

[0040] Fig. 4(a) is a diagram schematically showing an LW cross section of a multilayer ceramic capacitor in which external electrodes are formed on a laminate using the external electrode paste of the present embodiment, and Fig. 4(b) is a diagram schematically showing an LW cross section of a multilayer ceramic capacitor in which external electrodes are formed on a laminate using a conventional external electrode paste.

[0041] As shown in FIG. 4( b ), in the conventional multilayer ceramic capacitor 1, the first external electrode 3 a is formed on the laminate 12 using a conventional external electrode paste. The first external electrode 3 a has a convex shape with a thick center and a thin edge. In contrast, as shown in FIG. 4( a ), in the multilayer ceramic capacitor 10 of this embodiment, the first external electrode 30 a is formed on the laminate 12 using the external electrode paste of this embodiment. The first external electrode 30 a has a flat shape over the entire end face of the laminate 12, preventing the above-mentioned convex shape. The second external electrode 30 b is also formed with a similar flat shape. Therefore, the multilayer ceramic capacitor 10 having the external electrode 30 formed using the external electrode paste of this embodiment can be miniaturized. Furthermore, when compared at the same size, the external electrode 30 can be made thinner and the internal element can be made larger, thereby enabling a larger capacitance.

[0042] It should be noted that the method for applying the external electrode paste to the laminate 12 in this embodiment is not limited to the above-described method of immersion in the external electrode paste.

[0043] As described above, by using the external electrode paste of this embodiment, it is possible to improve the strength of the dry film while flattening the dry film, which makes it possible to miniaturize the electronic component while suppressing a decrease in strength even when the dry film is flattened and thinned.

[0044] In addition, in the above-mentioned external electrode paste, the BET specific surface area (SSA_Glass) of the glass powder is 0.38 m 2 / g or more. In this case, the particle size of the glass powder can be reduced assuming that the glass powder is spherical, and the glass powder is packed more densely in the external electrode paste due to convection during drying of the external electrode paste. This further reduces the void ratio in the dried film, thereby further improving the strength of the dried film.

[0045] In addition, in the above-mentioned external electrode paste, it is preferable that the D50_Cu of the Cu powder obtained by a laser diffraction / scattering particle size distribution measurement method is 3.0 μm or less. In this case, since the D50_Cu of the Cu powder can be reduced, the Cu powder is packed more densely within the external electrode paste due to convection during drying of the external electrode paste. Therefore, the void ratio in the dried film can be further reduced, and the strength of the dried film can be further improved.

[0046] Furthermore, in the above-mentioned external electrode paste, the ratio of Cu powder and glass powder to non-volatile components other than the solvent ((volume of Cu powder and volume of glass powder) / (volume of non-volatile components other than the solvent)) is preferably 50% by volume or more and 70% by volume or less. In this case, shape defects such as wrinkles can be suppressed in the dried film obtained after drying the external electrode paste, thereby further improving the strength of the dried film.

[0047] If the ratio exceeds 70% by volume, wrinkles will appear in the dried film when the external electrode paste dries, reducing its strength. If the ratio is less than 50% by volume, the acrylic resin and ethyl cellulose resin will adsorb to the Cu powder and glass powder, reducing the network chains formed. This results in a larger network and a lower crosslink density, reducing the strength of the dried film.

[0048] Furthermore, in the external electrode paste, the weight ratio of the acrylic resin to the ethyl cellulose resin is preferably 3:7 to 7:3. In this case, segregation of the Cu powder and glass powder in the external electrode paste can be suppressed, thereby suppressing stress concentration in a dried film using the external electrode paste, thereby improving the strength of the dried film.

[0049] 2. Experimental Examples Next, experimental examples will be specifically described. Experimental Examples 1 and 2 were performed as experimental examples. In Experimental Example 1, the weight ratio of the acrylic resin to the ethyl cellulose resin was changed, while the ratio of the Cu powder and the glass powder to the non-volatile components other than the solvent was changed. In Experimental Example 2, the weight ratio of the acrylic resin to the ethyl cellulose resin was set to 5:5, and the ratio of the Cu powder and the glass powder to the non-volatile components other than the solvent was set to 60 volume %, and the D50_Cu (BET specific surface area (SSA_Cu)) of the Cu powder was changed, while the D50_Glass (BET specific surface area (SSA_Glass)) of the glass powder was changed.

[0050] In the experimental example, a laminate having a length direction z L dimension of 0.6 mm, a width direction y W dimension of 0.3 mm, and a height direction x T dimension of 0.3 mm was used.

[0051] (1) Experimental Example 1 Experimental Example 1 will be described below.

[0052] A. Sample Preparation Acrylic resin, ethyl cellulose resin, Cu powder, glass powder, and solvent were prepared. The D50_Cu of the Cu powder was 0.3 μm. The D50_Glass of the glass powder was 0.57 μm. Furthermore, samples were prepared in which the weight ratio (AC:EC in Table 1) of the acrylic resin (AC) to the ethyl cellulose resin (EC in Table 1) was varied to 1:9, 2:8, 3:7, 4:6, 5:5, 6:4, 7:3, 8:2, and 9:1, and the ratio of Cu powder and glass powder to nonvolatile components other than the solvent ((volume of Cu powder and volume of glass powder) / (volume of nonvolatile components other than the solvent)) was varied to 45 vol%, 50 vol%, 55 vol%, 60 vol%, 65 vol%, 70 vol%, and 75 vol%. The weight ratio of Cu powder to glass powder was 50:5. The solvent was 35 wt% of the mixture of acrylic resin, ethyl cellulose resin, Cu powder, glass powder, and solvent. The acrylic resin, ethyl cellulose resin, Cu powder, glass powder, and solvent were mixed in a planetary mixer, and then dispersed and kneaded in a three-roll mill to prepare external electrode paste samples. Sixty-three types of samples were prepared, as shown in Table 1 below.

[0053] B. Evaluation of Samples (Dry Film Strength Test) A portion of the laminate was immersed in each of the prepared samples, and then the laminate coated with the sample was pulled out. The laminate coated with each sample was dried at a temperature of 150°C for 10 minutes. 100 laminates were used for each sample. After drying, each laminate was subjected to vibration at a frequency of 50 Hz for 1 minute at a temperature of 25°C using an MRV-MINI-M (manufactured by Wastec Co., Ltd.). Each laminate was observed with a metallurgical microscope to check for defects such as chipping and peeling in the dried film. Products with no chipping or peeling were rated as good products (◯), and products with chipping or peeling were rated as defective products (×).

[0054] Table 1 shows the results of the evaluation for each sample.

[0055]

[0056] C. Results When the ratio of Cu powder and glass powder to non-volatile components other than the solvent was 45% by volume and 75% by volume, the evaluation result was "X". Therefore, it is preferable that the ratio of Cu powder and glass powder to non-volatile components other than the solvent is greater than 45% by volume and less than 75% by volume. More preferably, the ratio is 50% by volume or more and 70% by volume or less.

[0057] Furthermore, when the weight ratio of the acrylic resin to the ethyl cellulose resin was 1:9, 2:8, 8:2, or 9:1, the result of the evaluation was "X." Therefore, assuming that the sum of the weight ratios of the acrylic resin and the ethyl cellulose resin is 10, it is preferable that the acrylic resin is more than 2 and less than 8, and that the ethyl cellulose resin is less than 8 and more than 2. More preferably, the weight ratio is 3:7 to 7:3.

[0058] (2) Experimental Example 2 Experimental Example 2 will be described below.

[0059] A. Sample Preparation Acrylic resin, ethyl cellulose resin, Cu powder, glass powder, and solvent were prepared. As the Cu powder, D50_Cu and SSA_Cu were used with a particle size of 0.1 μm and 8.0 μm. 2 / g, 0.15 μm and 5.4 m 2 / g, 0.32 μm and 2.7 m 2 / g, 0.75 μm and 1.1 m 2 / g, 1.5 μm and 0.53 m 2 / g, 3.0 μm and 0.27 m 2 / g, 3.1 μm and 0.25 m 2 As the glass powder, D50_Glass and SSA_Glass were prepared with a particle size of 0.21 μm and 47.0 μm, respectively. 2 / g, 0.32 μm and 31.0 m 2 / g, 1.2 μm and 8.2 m 2 / g, 4.6 μm and 0.58 m 2 / g, 0.57 μm and 12.0 m 2 / g, 4.6 μm and 0.58 m 2 / g, 5.5 μm and 0.38 m 2 / g, 6.1 μm and 0.32 m 2Since many of the glass powders in this experimental example are not spherical in shape, D50_Glass of the glass powder in this specification refers to the spherical equivalent diameter, and more specifically, the particle size at which the cumulative frequency is 50% in the particle size distribution of the powder measured by a laser diffraction / scattering particle size distribution measurement method.

[0060] Samples No. 1 to No. 18 shown in Table 2 were prepared as combinations of these Cu powders and glass powders. In each sample, the weight ratio of the acrylic resin to the ethyl cellulose resin was 5:5, and the ratio of the Cu powder and glass powder to the non-volatile components other than the solvent was 60% by volume. For each sample, the acrylic resin, ethyl cellulose resin, Cu powder, glass powder, and solvent were blended at 5% by weight, 50% by weight, 5% by weight, and 40% by weight, respectively, and mixed in a planetary mixer. The mixture was then dispersed and kneaded in a three-roll mill to prepare a sample of external electrode paste.

[0061] B. Evaluation of Samples The evaluation method of the samples was the same as in Experimental Example 1.

[0062] Table 2 shows the results of the evaluation for each sample.

[0063]

[0064] C. Results The evaluation results for Nos. 1 to 9 were "Good." In Nos. 1 to 9, the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) was 0.11 or more and 5.8 or less. Therefore, it is preferable that the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area (SSA_Glass) be 0.11 or more and 5.8 or less.

[0065] Furthermore, D50_Cu of the Cu powder was 3.0 μm or less in Nos. 1 to 9. Therefore, it is preferable that D50_Cu of the Cu powder is 3.0 μm or less.

[0066] In addition, in No. 1 to No. 9, the BET specific surface area (SSA_Glass) of the glass powder was 0.38 m 2 / g or more. Therefore, the BET specific surface area (SSA_Glass) of the glass powder was 0.38 m 2 / g or more is preferred.

[0067] On the other hand, the D50_Cu of the Cu powder was 3.1 μm, which was not included in the range of 3.0 μm or less, and the result of the evaluation for No. 18 was "x". 2 / g, and 0.38 m 2 In the cases of Nos. 13 and 15, which were outside the range of 0.11 to 5.8 / g, the evaluation result was "x." In addition, in the cases of Nos. 10 to 14, 16, and 17, which were outside the range of 0.11 to 5.8, the evaluation result was "x."

[0068] As described above, although the embodiments of the present invention have been disclosed in the above description, the present invention is not limited thereto. In other words, various modifications can be made to the above-described embodiments in terms of mechanism, shape, material, quantity, position, arrangement, etc., without departing from the scope of the technical idea and purpose of the present invention, and such modifications are included in the present invention.

[0069] <1> An external electrode paste used to form external electrodes of a multilayer ceramic electronic component, comprising: an acrylic resin and an ethyl cellulose resin, at least a portion of which are copolymerized; a Cu powder; a glass powder; and a solvent, wherein the ratio (SSA_Glass / SSA_Cu) of the BET specific surface area of ​​the glass powder (SSA_Glass) to the BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less.

[0070] <2> The BET specific surface area (SSA_Glass) of the glass powder is 0.38 m 2 / g or more.

[0071] <3> The external electrode paste according to <1> or <2>, wherein D50_Cu of the Cu powder obtained by a laser diffraction / scattering particle size distribution measurement method is 3.0 μm or less.

[0072] <4> The external electrode paste according to any one of <1> to <3>, wherein the ratio of the Cu powder and the glass powder to the non-volatile components other than the solvent is 50% by volume or more and 70% by volume or less.

[0073] <5> The paste for external electrodes according to any one of <1> to <4>, wherein the weight ratio of the acrylic resin to the ethyl cellulose resin is 3:7 to 7:3.

[0074] 10: Multilayer ceramic capacitor 12: Laminate 12a: First main surface 12b: Second main surface 12c: First side surface 12d: Second side surface 12e: First end surface 12f: Second end surface 14: Ceramic layer 16: Internal electrode layer 16a: First internal electrode layer 16b: Second internal electrode layer 30: External electrode 30a: First external electrode 30b: Second external electrode 31: External electrode paste 31a: External electrode paste x: Height direction y: Width direction z: Length direction

Claims

1. An external electrode paste used to form external electrodes of a multilayer ceramic electronic component, an acrylic resin and an ethyl cellulose resin, at least some of which are copolymerized; Cu powder, Glass powder, a solvent, A paste for external electrodes, wherein a ratio (SSA_Glass / SSA_Cu) of a BET specific surface area of ​​the glass powder (SSA_Glass) to a BET specific surface area of ​​the Cu powder (SSA_Cu) is 0.11 or more and 5.8 or less.

2. The BET specific surface area (SSA_Glass) of the glass powder is 0.38 m 2 2. The external electrode paste according to claim 1, wherein the external electrode paste has a viscosity of 1000 MPa or more.

3. 3. The external electrode paste according to claim 1, wherein D50_Cu of the Cu powder obtained by a laser diffraction / scattering particle size distribution measurement method is 3.0 μm or less.

4. 3. The external electrode paste according to claim 1, wherein the ratio of the Cu powder and the glass powder to the non-volatile components other than the solvent is 50% by volume or more and 70% by volume or less.

5. 3. The external electrode paste according to claim 1, wherein the weight ratio of the acrylic resin to the ethyl cellulose resin is 3:7 to 7:3.