Electronic component and method for manufacturing electronic component

Abstract

This electronic component is provided with an electronic component element body, a first external electrode, and a second external electrode. The electronic component element body is provided with a plurality of internal electrodes. The first external electrode comprises a metal film that does not contain a glass component, the metal film having a surface roughness maximum value of 1.0 μm. The second external electrode is formed so as to cover the first external electrode, and includes a conductor and a resin. The electronic component element body has a first end surface and a second end surface at which the internal electrodes are exposed, and a side surface connecting the first end surface and the second end surface. The first external electrode is formed on at least the internal electrode-exposed portion and the first end surface and the second end surface to a thickness in the range of 0.5 μm to 20 μm. The first external electrode has a covering part overlapping the side surface. The length of the covering part is 50 μm or less.

Description

Electronic component and method for manufacturing electronic component

[0001] The present invention relates to an electronic component having external electrodes on the end faces of an element body incorporating a laminate in which a plurality of elements are stacked.

[0002] Patent Document 1 describes a multilayer ceramic electronic component that includes a ceramic body, internal electrodes exposed to the outside of the ceramic body, electrode layers electrically connected to the internal electrodes, and a conductive resin layer formed to cover the electrode layers.

[0003] JP 2015-097248 A

[0004] However, in the configuration of Patent Document 1, the electrode layer is formed so as to cover the end faces of the internal electrodes. More specifically, the electrode layer is formed so as to cover only the internal electrodes exposed from the ceramic body, in other words, a part of the ceramic body. This means that the adhesion between the electrode layer and the conductive resin layer is reduced.

[0005] Furthermore, when the multilayer ceramic electronic component of Patent Document 1 is mounted on a substrate, the multilayer ceramic electronic component warps due to thermal stress, etc. This warping can cause cracks to form inside the ceramic body, which can lead to short circuits.

[0006] Therefore, an object of the present invention is to realize a highly reliable electronic component.

[0007] The electronic component of the present invention includes an electronic component body, a first external electrode, and a second external electrode. The electronic component body includes a plurality of internal electrodes. The first external electrode is made of a metal film that does not contain glass components and has a maximum surface roughness of 1.0 μm. The second external electrode is formed to cover the first external electrode and includes a conductor and a resin.

[0008] The electronic component body has a first end face where the internal electrode is exposed, a second end face, and a side face connecting the first end face and the second end face. The first external electrode is formed on at least the exposed portion of the internal electrode and the first and second end faces to a thickness in the range of 0.5 μm to 20 μm. The first external electrode has a covering portion overlapping the side face. The length of the covering portion is 50 μm or less.

[0009] In this configuration, a first external electrode made of an electrode film that does not contain glass is formed on the end face of the electronic component body. Because the electrode film does not contain glass, a reaction layer is not formed. In other words, the strength of the electronic component body is not reduced. Therefore, the bonding strength between the first external electrode and the electronic component body and the internal electrode is not reduced, and an increase in ESR can be suppressed.

[0010] Furthermore, the first external electrode is formed so as to have surface roughness over the entire first and second end faces of the electronic component body, thereby improving the sealing performance of the electronic component, i.e., improving the adhesion between the first external electrode and the second external electrode, and suppressing a decrease in ESR.

[0011] If the covering portion is large, cracks are likely to occur in the electronic component body, originating from the covering portion. However, the covering portion is very small, being 50 μm or less. Furthermore, the second external electrode is formed to cover the first external electrode. Therefore, stress on the electronic component body during mounting is likely to be applied to the second external electrode. In other words, the stress is applied to the second external electrode and not to the first external electrode. In other words, the occurrence of cracks in the electronic component body can be suppressed. Furthermore, since the functionality of the electronic component is not impaired, a highly reliable electronic component can be achieved.

[0012] The method for manufacturing an electronic component of the present invention includes the steps of: forming an electronic component body having a plurality of internal electrodes; forming a first external electrode, which is made of a metal film that does not contain glass components and has a maximum surface roughness of 1.0 μm, on at least the exposed portions of the internal electrodes in the electronic component body and on the first end face and second end face of the electronic component body by an aerosol deposition (AD) method; and forming a second external electrode, which includes a conductor and a resin formed so as to cover the first external electrode.

[0013] The electronic component body has a first end face and a second end face from which the internal electrodes are exposed, and side faces perpendicular to the first and second end faces. The first external electrode is formed on at least the exposed portions of the internal electrodes and the first and second end faces to a thickness in the range of 0.5 μm to 20 μm. The first external electrode has a covering portion overlapping the side faces. The covering portion is formed to have a length of 50 μm or less.

[0014] In this method, a first external electrode made of an electrode film that does not contain glass is formed on the end face of the electronic component body. Because this electrode film does not contain glass, a reaction layer is not formed. In other words, the strength of the electronic component body is not reduced. Therefore, the bonding strength between the first external electrode, the electronic component body, and the internal electrodes is not reduced, so an increase in ESR can be suppressed. Furthermore, because the first external electrode is formed using the AD method, it can be formed using a simple process.

[0015] Furthermore, the first external electrode is formed so as to have surface roughness over the entire first and second end faces of the electronic component body, thereby improving the sealing performance of the electronic component, i.e., improving the adhesion between the first external electrode and the second external electrode, and suppressing a decrease in ESR.

[0016] If the covering portion is large, cracks are likely to occur in the electronic component body, originating from the covering portion. However, the covering portion is very small, being 50 μm or less. Furthermore, the second external electrode is formed to cover the first external electrode. Therefore, stress on the electronic component body during mounting is likely to be applied to the second external electrode. In other words, the stress is applied to the second external electrode and not to the first external electrode. In other words, the occurrence of cracks in the electronic component body can be suppressed. Furthermore, since the functionality of the electronic component is not impaired, a highly reliable electronic component can be achieved.

[0017] According to the present invention, highly reliable electronic components can be realized.

[0018] FIG. 1 is an external perspective view of a multilayer ceramic capacitor according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of the multilayer ceramic capacitor according to the first embodiment of the present invention. FIG. 3 is an enlarged view showing the connection structure between first external electrodes and second external electrodes in an electronic component body of the multilayer ceramic capacitor and the body. FIG. 4 is a flowchart showing an example of a schematic flow of a method for manufacturing the multilayer ceramic capacitor according to the first embodiment of the present invention. FIG. 5 is a diagram showing the configuration of an apparatus for forming first external electrodes by the AD method. FIG. 6 is a cross-sectional view showing the configuration of a multilayer ceramic capacitor according to a second embodiment of the present invention.

[0019] [First Embodiment] An electronic component and a method for manufacturing an electronic component according to a first embodiment of the present invention will be described with reference to the drawings. In each embodiment of the present invention, a multilayer ceramic capacitor will be described as an example of the electronic component. However, the configuration of this embodiment can be applied to any chip-type capacitor having external electrodes on the end surfaces of the electronic component body. For example, a chip-type capacitor has an electronic component body formed by laminating dielectric sheets. In a chip-type capacitor, a functional portion of the capacitor is formed inside the electronic component body. In a chip-type capacitor, electrodes of the functional portion of the capacitor are exposed from the end surfaces of the electronic component body, and external electrodes are formed on these exposed surfaces.

[0020] (Explanation of the configuration of the multilayer ceramic capacitor 10) Fig. 1 is an external perspective view of the multilayer ceramic capacitor according to the first embodiment of the present invention. Fig. 2 is a cross-sectional view showing the configuration of the multilayer ceramic capacitor according to the first embodiment of the present invention. Fig. 3 is an enlarged view showing the connection structure between first external electrodes and second external electrodes in an electronic component body of the multilayer ceramic capacitor and the body. Note that in Figs. 2 and 3, to clearly illustrate the configuration, the dimensions in each direction are appropriately emphasized, and the dimension in the height direction (z-axis direction in the drawings) is particularly emphasized.

[0021] As shown in FIGS. 1 and 2, the multilayer ceramic capacitor 10 includes an element body 11, an electrode layer 61, and an electrode layer 62.

[0022] The element body 11 has a substantially rectangular parallelepiped shape and has end faces 111, 112, a top face 113, a bottom face 114, and a plurality (two) of side faces 115. The plurality (two) of side faces 115 are surfaces that connect to the end faces 111, 112, the top face 113, and the bottom face 114. The element body 11 corresponds to an "electronic component element body" of the present invention. The end face 111 corresponds to a "first end face" of the present invention, and the end face 112 corresponds to a "second end face" of the present invention. The top face 113, the bottom face 114, and the side face 115 correspond to "side faces" of the present invention. Note that the top face 113 and the bottom face 114 are used for convenience of explanation, and when the multilayer ceramic capacitor 10 is mounted on a circuit board, either face may face the circuit board.

[0023] The element body 11 includes a plurality of internal electrodes 20, 30 and a multilayer ceramic layer 50. The multilayer ceramic layer 50 is formed by stacking dielectric sheets.

[0024] The internal electrodes 20, 30 are flat films having a first end face, a second end face, a flat film surface on the top face side, and a flat film surface on the bottom face side. The internal electrodes 20, 30 are made of, for example, nickel.

[0025] More specifically, the element body 11 is formed as follows: First, a conductive paste for the internal electrodes is printed in a predetermined pattern on a dielectric sheet using screen printing or the like, thereby forming the internal electrode pattern (internal electrodes 20, 30).

[0026] The element body 11 is formed by alternately stacking dielectric sheets (hereinafter referred to as first sheets) on which internal electrodes 20 are formed and dielectric sheets (hereinafter referred to as second sheets) on which internal electrodes 30 are formed. As shown in Fig. 2 , the internal electrodes 20 are exposed on an end face 111, and the internal electrodes 30 are exposed on an end face 112. Dielectric sheets on which no internal electrode patterns are formed are stacked so as to be located on a top face 113 and a bottom face 114 of the element body 11.

[0027] Next, the element body 11 is fired. An electrode layer 61 is formed on an end face 111 of the element body 11, and an electrode layer 62 is formed on an end face 112 of the element body 11. The electrode layer 61 includes a first external electrode 611, a second external electrode 612, and a plating layer 613. The electrode layer 62 includes a first external electrode 621, a second external electrode 622, and a plating layer 623. The plating layers 613 and 623 correspond to the "third external electrode" of the present invention. The structures of the electrode layers 61 and 62 will be described in more detail below.

[0028] With this configuration, the internal electrodes 20 and 30 face each other with the dielectric sheet sandwiched between them, and function as a capacitor having a predetermined capacitance.

[0029] The first sheet and the second sheet are flat membrane-shaped. The multiple first sheets and the multiple second sheets are arranged so that their respective flat membrane surfaces are approximately parallel to the top surface 113 and the bottom surface 114 of the element body 11. As described above, the multiple first sheets and the multiple second sheets are arranged alternately in a direction perpendicular to the top surface 113 and the bottom surface 114 (the height direction of the element body 11 (z-axis direction in the figure)). Note that, although the number of the multiple first sheets is three and the number of the multiple second sheets is four in FIG. 2, this is not a limitation.

[0030] In this stacked state, the end faces 211 (see FIG. 2 ) of the multiple first sheet internal electrodes 20 are located at approximately the same position in side view. The end faces 311 of the multiple second sheet internal electrodes 30 are located at approximately the same position in side view. The end faces 211 of the multiple first sheet internal electrodes 20 protrude beyond the end faces 312 of the multiple second sheet internal electrodes 30. The end faces 311 of the multiple second sheet internal electrodes 30 protrude beyond the end faces 212 of the multiple first sheet internal electrodes 20.

[0031] End faces 211 of the multiple first sheet internal electrodes 20 are exposed to the outside of the element body 11 from end faces 111 of the element body 11. Furthermore, the multiple second sheet internal electrodes 30 are exposed to the outside of the element body 11 from end faces 112 of the element body 11.

[0032] The first external electrodes 611, 621 are metal films. The first external electrodes 611, 621 are composed of particles made of a metal material, taking into account the shape, conductivity, and formation method described below. The first external electrodes 611, 621 preferably contain at least one of copper, nickel, tin, and zinc. The first external electrodes 611, 621 do not contain glass components such as glass frit. Note that the phrase "does not contain glass frit, etc." does not include a configuration in which glass components are inevitably mixed in during the manufacturing process.

[0033] The second external electrodes 612, 622 are made of conductive resin electrodes and preferably contain silver, copper, nickel, tin, or the like, either singly or as an alloy containing at least one of silver, copper, nickel, tin, or the like.

[0034] The plating layers 613 and 623 are formed by plating, for example, Ni / Sn plating layers formed as two layers.

[0035] The electrode layer 61 is formed on the entire end face 111 of the element body 11, part of the top face 113, the bottom face 114, and part of the side face 115. The electrode layer 61 is formed to a predetermined thickness (height) from the end face 111 of the element body 11.

[0036] The electrode layer 62 is formed on the entire end face 112 of the element body 11, part of the top face 113, the bottom face 114, and part of the side face 115. The electrode layer 62 is formed to a predetermined thickness (height) from the end face 112 of the element body 11.

[0037] The multilayer ceramic capacitor 10 is realized by the above configuration.

[0038] 2 and 3 , the structures of the electrode layers 61 and 62 will be described in more detail. As described above, the electrode layer 61 includes a first external electrode 611, a second external electrode 612, and a plating layer 613. The electrode layer 62 includes a first external electrode 621, a second external electrode 622, and a plating layer 623.

[0039] The first external electrode 611 is formed on the end surface 111 of the element body 11. In other words, the first external electrode 611 is formed so as not to extend onto the top surface 113, bottom surface 114, or side surface 115, excluding a covering portion 150 described below. The second external electrode 612 is formed so as to cover the entire first external electrode 611, and also to cover part of the top surface 113, part of the bottom surface 114, and part of the side surface 115. The nickel plating layer of the plating layer 613 is formed so as to cover the second external electrode 612. Furthermore, a tin plating layer is formed so as to cover this nickel plating layer.

[0040] The first external electrode 621 is formed on the end surface 112 of the element body 11. In other words, the first external electrode 621 is formed so as not to extend onto the top surface 113, bottom surface 114, or side surface 115, excluding a covering portion 150 described below. The second external electrode 622 is formed so as to cover the entire first external electrode 621, and also to cover a portion of the top surface 113, a portion of the bottom surface 114, and a portion of the side surface 115. The nickel plating layer of the plating layer 623 is formed so as to cover the second external electrode 622. Furthermore, a tin plating layer is formed so as to cover this nickel plating layer.

[0041] The plating layers 613 and 623 are nickel-plated to improve corrosion resistance, strength, and ductility, while the tin-plated layers 613 and 623 are tin-plated to improve solderability and conductivity when the multilayer ceramic capacitor 10 is mounted.

[0042] Next, the structure of the covering portion 150 of the first external electrodes 611, 621 will be described. The covering portion 150 refers to the range on the top surface 113, bottom surface 114, and side surface 115 that may be covered by the first external electrodes 611, 621. The covering portion 150 is formed so as to cover the corner formed by the top surface 113, bottom surface 114, and side surface 115 with respect to the end surface 111. The covering portion 150 is formed so as to cover the corner formed by the top surface 113, bottom surface 114, and side surface 115 with respect to the end surface 112. The dimension of the covering portion 150 is preferably 50 μm or less.

[0043] It is more preferable that the covering portion 150 is not formed. In other words, it is preferable that the first external electrode 611 is formed only on the end surface 111. It is also preferable that the first external electrode 621 is formed only on the end surface 112.

[0044] Here, a comparison is made between a conventional multilayer ceramic capacitor and the multilayer ceramic capacitor 10 of the first embodiment. The conventional multilayer ceramic capacitor has a large coating that contains a glass component. Therefore, the coating adheres closely to the element body and is not easily peeled off. Therefore, the element body is prone to cracks that originate at the points where the coating and the element body come into contact due to undesired external forces (such as stress due to bending). If moisture penetrates these cracks, there is a risk of short circuits occurring in the internal electrodes.

[0045] However, the cover 150 of the multilayer ceramic capacitor 10 in the first embodiment is formed with very small dimensions. Furthermore, the first external electrodes 611, 621 do not contain glass components. The second external electrodes 612, 622 substantially cover the top surface 113, bottom surface 114, and side surface 115. The second external electrodes 612, 622 are resin electrodes. Therefore, stress (e.g., thermal stress, bending stress, or flexural stress) applied to the element body 11 during mounting of the multilayer ceramic capacitor 10 is less likely to be applied to the cover 150 and more likely to be applied to the second external electrodes 612, 622, which are resistant to stress. In other words, the second external electrodes 612, 622 can absorb the stress during mounting. This reduces the stress applied to the element body 11. Furthermore, because the first external electrodes 611, 621 that form the cover 150 do not contain a glass component, even if stress is applied to the cover 150, the cover 150 peels off from the element body 11, thereby suppressing stress on the inside of the element body 11. This makes it possible to suppress the occurrence of cracks in the element body 11.

[0046] The first external electrode 611 has a predetermined bonding strength with the end face 111. Furthermore, the first external electrode 611 has an even higher bonding strength with the internal electrode 20. Similarly, the first external electrode 621 has a predetermined bonding strength with the end face 112. Furthermore, the first external electrode 621 has an even higher bonding strength with the internal electrode 30. As a result, even if the cover 150 peels off, electrical continuity between the first external electrode 611 and the internal electrode 20 and between the first external electrode 621 and the internal electrode 30 is ensured. In other words, peeling off the cover 150 can relieve stress applied to the joint between the first external electrode 611 and the internal electrode 20 and the joint between the first external electrode 621 and the internal electrode 30, thereby ensuring electrical continuity between them.

[0047] Furthermore, the first external electrodes 611, 621 have a maximum surface roughness (Rz) of 1.0 μm or more and 1.5 μm or less, as determined from a roughness curve based on JIS B0601-2001. Here, the maximum surface roughness (Rz) refers to, as described above, the first external electrode 611 is covered with the second external electrode 612 made of a resin containing silver. Similarly, the first external electrode 621 is covered with the second external electrode 622 made of a resin containing silver.

[0048] That is, as shown in FIG. 3 , silver contained in the second external electrode 612 penetrates into the rough portion of the surface of the first external electrode 611 (the surface that abuts against the second external electrode 612). Furthermore, silver contained in the second external electrode 622 penetrates into the rough portion of the surface of the first external electrode 621 (the surface that abuts against the second external electrode 622) (see FIG. 3 ). This improves adhesion between the first external electrode 611 and the second external electrode 612, and between the first external electrode 621 and the second external electrode 622, due to the anchor effect. This increases the conductivity and bonding strength between the first external electrode 611 and the second external electrode 612, and between the first external electrode 621 and the second external electrode 622. Furthermore, the sealing performance of the multilayer ceramic capacitor 10 is improved.

[0049] (Method for manufacturing the multilayer ceramic capacitor 10) The multilayer ceramic capacitor 10 having the above-described configuration is manufactured, for example, as follows. Fig. 4 is a flowchart showing an example of a schematic flow of the method for manufacturing the multilayer ceramic capacitor according to this embodiment. Fig. 5 is a diagram of an apparatus for forming the first external electrodes 611, 621 by the AD method.

[0050] The element body 11 is formed (S11). Specifically, first sheets on which the internal electrodes 20 are formed and second sheets on which the internal electrodes 30 are formed are alternately laminated, and dielectric sheets on which no internal electrode patterns are formed are laminated on the top surface 113 and the bottom surface 114 of the laminate. In this way, the element body 11 is formed. This process is performed in the state of a multi-substrate on which multiple element bodies 11 can be formed collectively. By dividing this multi-substrate into individual element bodies 11, the internal electrodes 20 are exposed on the end surface 111 and the internal electrodes 30 are exposed on the end surface 112, as shown in FIG. 2 . This element body 11 is fired.

[0051] Next, first external electrodes 611 are formed on the end faces 211 of the internal electrodes 20 of the first sheet and on the end face 111 of the element body 11. The first external electrodes 611 are formed using the AD method (S12). The thickness of the first external electrodes 611 is preferably 0.5 μm or more and 20 μm or less, and is preferably 5 μm.

[0052] 5 , a plurality of element bodies 11 are fixed on a stage 92 and placed in a chamber 91. At least the tip (ejection end) of an aerosol generator 93 is inserted into the chamber 91. The aerosol generator 93 generates an aerosol by introducing copper powder 600 into a carrier gas, and sprays the aerosol onto the end faces 111 of the element bodies 11.

[0053] At this time, by appropriately setting the aerosol specifications (e.g., the volume ratio of copper powder 600 contained in the carrier gas) and the spraying conditions (e.g., the number of sprays, the spraying strength, etc.), the copper powder 600 is struck against the end surface 111 of the base body 11 and piled up to a predetermined height (predetermined thickness).

[0054] As a result, the first external electrode 611 is formed on the end surface 111 of the element body 11 and the end surface 211 of the internal electrode 20 of the first sheet (see FIGS. 2 and 3). At this time, if the corners (ridges) where the end surface 111 intersects with a portion of the top surface 113, a portion of the bottom surface 114, and a portion of the side surface 115 are chamfered, these portions become the covering portion 150, and the first external electrode 611 is also formed on the covering portion 150 (a portion of the top surface 113, a portion of the bottom surface 114, and a portion of the side surface 115) (see FIGS. 2 and 3). The end surface 211 corresponds to the "exposed portion" of the present invention. The particle size of the copper powder 600 is, for example, about 3 μm, but may be 2 μm or less.

[0055] Next, first external electrodes 621 are formed on the end faces 112 of the element body 11 and the end faces 311 of the internal electrodes 30 of the second sheet using the AD method (S13). The first external electrodes 621 are formed in the same shape as the first external electrodes 611. The thickness of the first external electrodes 621 is preferably 0.5 μm or more and 20 μm or less. The method for forming the first external electrodes 621 is the same as the method for forming the first external electrodes 611, so a description thereof will be omitted.

[0056] Next, the second external electrode 612 is formed so as to cover the first external electrode 611. The second external electrode 612 is formed by, for example, dipping. Furthermore, a plating layer 613 is formed so as to cover the second external electrode 612 (S14). In this way, the electrode layer 61 functions as an external electrode of the multilayer ceramic capacitor 10.

[0057] Next, the second external electrode 622 is formed so as to cover the first external electrode 621. The second external electrode 622 is formed by, for example, dipping processing. Furthermore, a plating layer 623 is formed so as to cover the second external electrode 622 (S15). In this way, the electrode layer 62 functions as an external electrode of the multilayer ceramic capacitor 10.

[0058] By using the manufacturing method described above, the multilayer ceramic capacitor 10 having the above-described configuration can be manufactured easily and more reliably.

[0059] The external electrodes of the multilayer ceramic capacitor 10 are realized by forming the first external electrodes 611, 621 using the AD method. That is, the first external electrodes 611, 621 can be formed by a simple method.

[0060] Furthermore, the first external electrodes 611, 621 do not contain glass components. That is, no reaction layer is formed between the multilayer ceramic layer 50 and the first external electrodes 611 and 621. This prevents the bond strength between the cover 150 of the first external electrode 611 and the element body 11, and the bond strength between the cover 150 of the first external electrode 621 and the element body 11 from becoming too high. This prevents peeling from occurring in areas other than those that are electrically conductive when stress is applied to the multilayer ceramic capacitor 10, thereby preventing a substantial decrease in the strength of the electrically conductive areas.

[0061] Furthermore, the second external electrode 612 is formed so as to cover the first external electrode 611. The second external electrode 622 is formed so as to cover the first external electrode 621. With this configuration, when stress is applied to the multilayer ceramic capacitor 10, the second external electrodes 612, 622 absorb the stress, thereby preventing the stress from being transmitted to the first external electrodes 611, 621 and the cover 150. Furthermore, because the first external electrodes 611, 621 that form the cover 150 do not contain a glass component, even if stress is applied to the cover 150, the cover 150 peels off from the element body 11, thereby preventing stress from entering the interior of the element body 11. This prevents cracks from occurring in the element body 11 due to stress when the multilayer ceramic capacitor 10 is mounted.

[0062] As a result of the above, a highly reliable multilayer ceramic capacitor 10 can be realized.

[0063] Second Embodiment A multilayer ceramic capacitor according to a second embodiment of the present invention will be described with reference to the drawings. The multilayer ceramic capacitor according to the second embodiment differs from the multilayer ceramic capacitor 10 according to the first embodiment in the shapes of the second external electrodes and plated electrodes. The other configuration of the ceramic capacitor according to the second embodiment is the same as that of the multilayer ceramic capacitor according to the first embodiment, and a description of similar parts will be omitted.

[0064] FIG. 6 is a cross-sectional view showing the configuration of a multilayer ceramic capacitor according to a second embodiment of the present invention. In FIG. 6, the bottom surface 114 is the mounting surface for mounting on a substrate. As shown in FIG. 6, the multilayer ceramic capacitor 10A includes second external electrodes 612a, 622a. The second external electrodes 612a, 622a are not formed on the surface facing the top surface 113. Similarly, the plated electrodes 613a, 623a are not formed on the surface facing the top surface 113.

[0065] In other words, the second external electrode 612a is formed so as to cover the portions of the end faces 111, bottom face 114, and side faces 115 of the element body 11 where the first external electrode 611 is formed. The second external electrode 622a is formed so as to cover the portions of the end faces 112, bottom face 114, and side faces 115 of the element body 11 where the first external electrode 621 is formed.

[0066] Furthermore, the plating electrode 613a is formed so as to cover the portion where the second external electrode 612a is formed, and the plating electrode 623a is formed so as to cover the portion where the second external electrode 622a is formed.

[0067] In the second embodiment, the multilayer ceramic capacitor 10A has the first external electrodes 611, 621 formed only on the end faces 111 and 112, excluding the covering portion 150. This makes it possible to realize a highly reliable multilayer ceramic capacitor 10A.

[0068] In the above-described configuration, an example has been shown in which the plating electrodes 613a, 623a are not formed on the surface facing the top surface 113. However, the plating electrodes 613a, 623a may be formed on the surface facing the top surface 113 so as to cover the first external electrodes 611, 621.

[0069] DESCRIPTION OF SYMBOLS 10, 10A... Multilayer ceramic capacitor 11... Element body 20, 30... Internal electrode 50... Multilayer ceramic layer 61, 62... Electrode layer 91... Chamber 92... Stage 93... Aerosol generator 111, 112... End surface 113... Top surface 114... Bottom surface 115... Side surface 150... Covering portion 211, 212, 311, 312... End surface 600... Copper powder 611, 621... First external electrode 612, 622, 612a, 622a... Second external electrode 613, 623... Plating layer

Claims

1. An electronic component comprising: an electronic component body having a plurality of internal electrodes; a first external electrode made of a metal film containing no glass components, the metal film having a maximum surface roughness of 1.0 μm; and a second external electrode formed to cover the first external electrode and containing a conductor and a resin, wherein the electronic component body has a first end face and a second end face at which the internal electrodes are exposed, and a side face connecting the first end face and the second end face, the first external electrode is formed to a thickness in the range of 0.5 μm to 20 μm on at least the exposed portions of the internal electrodes, and the first end face and the second end face, the first external electrode has a covering portion overlapping the side face, and the length of the covering portion is 50 μm or less.

2. The electronic component according to claim 1, wherein the maximum surface roughness of said metal film is 1.5 μm or less.

3. The electronic component according to claim 1 or 2, further comprising a third external electrode covering the second external electrode, the third external electrode being formed by plating.

4. A method for manufacturing an electronic component, comprising: a step of forming an electronic component body having a plurality of internal electrodes; a step of forming a first external electrode, which is made of a metal film not containing a glass component and has a maximum surface roughness of 1.0 μm, on at least exposed portions of the internal electrodes in the electronic component body and on a first end face and a second end face of the electronic component body by an AD (Aerosol Deposition) method; and a step of forming a second external electrode, which contains a conductor and a resin, so as to cover the first external electrode, wherein the electronic component body has a first end face and a second end face on which the internal electrodes are exposed, and side faces perpendicular to the first end face and the second end face, the first external electrode is formed at least on the exposed portions of the internal electrodes, and on the first end face and the second end face with a thickness in the range of 0.5 μm to 20 μm, and the first external electrode has a covering portion overlapping the side faces, and the covering portion is formed so as to have a length of 50 μm or less.

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