WO2013108533A1 - Ceramic electronic component - Google Patents

Abstract

When a plating film is formed by a wet plating process on an external electrode provided to a ceramic electronic component, such as a stacked ceramic capacitor, and formed thereon by baking of a conductive paste containing a glass component for example, there are instances in which the glass component situated in the vicinity of end edges of the external electrode is dissolved by the plating solution, resulting in erosion and embrittlement of the component body in the vicinity of the end edges of the external electrode. Glass regions (38, 39) extending at least from the end edges (34, 35) of external electrodes (32, 33) to the vicinity thereof, in which glass containing between 23 mol% and 74 mol%, inclusive, of silicon oxide is present, are formed on the surface of a component body (22). Glass containing between 23 mol% and 74 mol%, inclusive, of silicon oxide has been found to resist dissolution by plating solutions.

Description

Ceramic electronic components

The present invention relates to a ceramic electronic component, and more particularly, to a ceramic electronic component in which a plating film by wet plating is formed on an external electrode.

In a multilayer ceramic capacitor mounted using solder, wet plating such as electrolytic plating is usually applied to an external electrode formed by baking. For example, a Ni plating film and an Sn plating film thereon are external electrodes. Thus, it is possible to improve the mountability, more specifically, the solderability of the external electrode.

However, it is known that the plating solution used in carrying out wet plating as described above has a more or less undesirable effect on ceramic electronic components such as multilayer ceramic capacitors.

The above-mentioned undesirable effects often appear as a decrease in the mechanical strength of the ceramic electronic component, such as cracking during mounting substrate reflow or reflow or mounting. This will be described with reference to FIG. 9 and FIG.

9 and 10 are plan views showing the appearance of a multilayer ceramic capacitor 1 as an example of a ceramic electronic component. The multilayer ceramic capacitor 1 includes a rectangular parallelepiped component body 2. External electrodes 3 and 4 are formed on a pair of opposed end faces of the component body 2, respectively. The external electrodes 3 and 4 have respective end edges 5 and 6 located on a pair of main surfaces 7 and 8 facing each other and a pair of side surfaces 9 and 10 facing each other.

As shown in FIG. 10, plating films 11 and 12 are formed on the external electrodes 3 and 4 by wet plating. FIG. 9 shows a state before the plating films 11 and 12 are formed.

When a bending test for measuring the bending strength of such a multilayer ceramic capacitor 1 was carried out, it was found that the crack generation mode was different before and after plating. That is, before plating, as shown in FIG. 9, the crack 13 is likely to occur so as to cross the central portion of the component body 2. On the other hand, after plating, as shown in FIG. 10, the crack 14 is likely to occur in the component body 2 starting from the portion where the edges 5 and / or 6 of the external electrodes 3 and / or 4 are located.

From this, it can be seen that the plating solution severely deteriorates the component main body 2 particularly in the portion where the edges 5 and 6 of the external electrodes 3 and 4 are located. This is because the glass component contained in the conductive paste for forming the external electrodes 3 and 4 permeates into the ceramic portion of the component body 2 in the baking process. The glass component located in the vicinity of the edges 5 and 6 of the external electrodes 3 and 4 that are easy to touch is melted by the plating solution, so that the component body 2 is in the vicinity of the edges 5 and 6 of the external electrodes 3 and 4. It can be inferred that it is caused by erosion and fragility.

On the other hand, the following have been proposed as techniques for suppressing the adverse effects of the plating solution.

Japanese Patent Laying-Open No. 2010-245095 (Patent Document 1) discloses a multilayer ceramic electronic component in which the entire exposed surface of a ceramic body is covered with glass to prevent the penetration of a plating solution into the inside of the body. Is described. However, since the glass described in Patent Document 1 can be dissolved in the plating solution, the above-described problems caused by the melting of the glass cannot be solved.

In Japanese Patent Application Laid-Open No. 2011-165725 (Patent Document 2), although not an external electrode formed by baking, by applying a water repellent treatment agent to the edge of the external electrode formed by plating, A method of manufacturing a multilayer electronic component that prevents intrusion is described. However, since the external electrode described in Patent Document 2 is formed by plating, it does not contain glass. Therefore, the problem that the glass as described above is melted by the plating solution is not encountered.

In Japanese Patent Application Laid-Open No. 2007-103845 (Patent Document 3), a conductive paste used for forming a terminal electrode of a multilayer ceramic electronic component having excellent plating solution resistance, particularly a glass powder contained in the conductive paste. The ingredients are listed. However, since the glass described in Patent Document 3 can be dissolved in the plating solution as in the case of the glass described in Patent Document 1, the above-described problem caused by melting of the glass cannot be solved.

The above problem is not limited to multilayer ceramic electronic components, but can also be applied to single-layer ceramic electronic components.

JP 2010-245095 A JP 2011-165725 A JP 2007-103845 A

Therefore, an object of the present invention is to provide a multilayer ceramic electronic component that can solve the above-described problems.

The present invention includes a substantially rectangular parallelepiped-shaped main body having a pair of principal surfaces opposed to each other, a pair of side surfaces opposed to each other, and a pair of end surfaces opposed to each other, and a glass component. An external electrode formed by baking of a conductive paste, and formed on an end face of a component main body and having an end edge located on at least one of a main surface and a side surface adjacent to the end face; In order to solve the above technical problem, at least an edge of the external electrode is provided on the surface of the component body. In the vicinity thereof, a glass region in which a glass containing silicon oxide of 23 mol% or more and 74 mol% or less exists is formed.

It was found that the glass containing 23 mol% or more and 74 mol% or less of silicon oxide described above is difficult to dissolve in the plating solution.

Preferably, the distance from the edge position of the external electrode to the edge of the glass region measured is not more than the distance from the end surface of the component body to the edge of the external electrode.

In a preferred embodiment, the glass region is formed by applying and baking a glass paste in which a glass frit containing silicon oxide is dispersed in a region adjacent to an end surface on at least one of the main surface and the side surface of the component body. The edge of the external electrode is positioned so as to expose the edge of the glass layer. In this case, the distance from the end surface of the component body to the edge of the glass layer is preferably in the range of 1/4 to 1/2 times the distance between the pair of end surfaces of the component body.

In another preferred embodiment, the glass region is a glass containing conductive metal powder and silicon oxide to form part of the external electrode in a region adjacent to the end face on at least one of the main surface and the side surface of the component body. By applying and baking a conductive paste containing frit, it is provided by the glass component that exudes from the conductive paste. In this case, the distance from the edge position of the external electrode to the edge of the glass region measured may be in the range of 1/10 to 1 times the distance from the end surface of the component body to the edge of the external electrode. preferable.

In particular, the present invention includes a component main body including a plurality of laminated ceramic layers and an internal electrode disposed along an interface between the ceramic layers, and an end of the internal electrode is exposed at the end face, The present invention is advantageously applied to a multilayer ceramic electronic component connected to the end of the internal electrode exposed at the end face of the component body.

According to the present invention, the glass region where the glass that is difficult to dissolve in the plating solution is formed in the vicinity of the edge of the external electrode. It is suppressed. Therefore, the generation of cracks starting from the portion where the edge of the external electrode is located as described above with reference to FIG. 10 can be advantageously suppressed. Therefore, the mechanical strength of the ceramic electronic component can be increased.

1 is a cross-sectional view showing a multilayer ceramic capacitor 21 according to a first embodiment of the present invention. FIG. 2 is a cross-sectional view for explaining a method of forming an external electrode of the multilayer ceramic capacitor 21 shown in FIG. 1 and shows a state in which glass layers 40 and 41 are formed. FIG. 3 is a cross-sectional view for explaining a method for forming an external electrode of the multilayer ceramic capacitor 21 shown in FIG. 1 and shows a state in which external electrodes 32 and 33 are formed after the stage shown in FIG. 2. It is sectional drawing which shows the multilayer ceramic capacitor 51 by 2nd Embodiment of this invention. FIG. 5 is a cross-sectional view for explaining a method of forming an external electrode of the multilayer ceramic capacitor 51 shown in FIG. And 63 are formed. FIG. 6 is a cross-sectional view for explaining a method for forming an external electrode of the multilayer ceramic capacitor 51 shown in FIG. 4, after applying a conductive paste on the end faces 30 and 31 of the component body 22 after the stage shown in FIG. 5; Furthermore, the state after implementing a baking process is shown. It is a top view of the structure in the state shown in FIG. It is a figure which shows the density | concentration distribution of Si obtained by the line analysis by XRF along the line shown in FIG. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view illustrating a state in which a crack 13 is formed in a multilayer ceramic capacitor 1 before plating in order to explain a problem to be solved by the present invention. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a plan view illustrating a state in which cracks 14 are formed in a multilayer ceramic capacitor 1 after plating in order to explain a problem to be solved by the present invention.

Hereinafter, a multilayer ceramic capacitor will be described as an example of a ceramic electronic component to which the present invention is applied.

[First Embodiment]
Referring to FIG. 1, a multilayer ceramic capacitor 21 according to a first embodiment of the present invention includes a component body 22 having a multilayer structure. The component body 22 includes a plurality of laminated ceramic layers 23 and a plurality of first and second internal electrodes 24 and 25 arranged along an interface between the ceramic layers 23. The first internal electrode 24 and the second internal electrode 25 are opposed to each other in a part of each, and are alternately arranged as viewed in the stacking direction. The internal electrodes 24 and 25 are mainly composed of nickel, for example.

The component body 22 includes first and second main surfaces 26 and 27 facing each other, first and second side surfaces facing each other (a surface parallel to a paper surface not shown), and first and second end surfaces facing each other. It has a substantially rectangular parallelepiped shape with 30 and 31.

The end portions of the first and second internal electrodes 24 and 25 are exposed at the first and second end faces 30 and 31 of the component main body 22, respectively. The first and second end surfaces 30 and 31 of the component body 22 are electrically connected to the end portions of the first and second internal electrodes 24 and 25, respectively. External electrodes 32 and 33 are formed. The first and second external electrodes 32 and 33 have respective end edges 34 and 35 positioned on the main surfaces 26 and 27 adjacent to the end surfaces 30 and 31, and in this embodiment, although not shown in the figure. It is also located on the side. External electrodes 32 and 33 are formed, for example, by baking a conductive paste mainly composed of copper.

Plated films 36 and 37 are formed on the external electrodes 32 and 33, respectively. The plating films 36 and 37 are composed of, for example, a plating layer mainly containing nickel and a plating layer mainly containing tin formed thereon.

As a characteristic feature of the present invention, it includes at least 23 mol% and not more than 74 mol% of silicon oxide on the surface of the component body 22 and at least from the edges 34 and 35 of the external electrodes 32 and 33 to the vicinity thereof. Glass regions 38 and 39 in which glass is present are formed. In this embodiment, the glass regions 38 and 39 are provided by glass layers 40 and 41 made of glass containing 23 mol% or more and 74 mol% or less of silicon oxide. The glass layers 40 and 41 are formed along the interfaces between the main surfaces 26 and 27 and the side surfaces of the component body 22 and the external electrodes 32 and 33.

A distance A from each position of the edges 34 and 35 of the external electrodes 32 and 33 to each edge 42 and 43 of the glass layers 40 and 41 is determined from each of the end faces 30 and 31 of the component body 22 to the external electrode. The distance B to the end edges 34 and 35 of each of 32 and 33 is preferably equal to or less than B.

Next, a method for manufacturing the multilayer ceramic capacitor 21 will be described.

First, the component body 22 is prepared. For the component body 22, a ceramic green sheet containing a dielectric ceramic material is prepared, and then a conductive paste film to be the internal electrodes 24 and 25 is formed on the ceramic green sheet with a predetermined pattern. By laminating a plurality of ceramic green sheets including a ceramic green sheet on which a paste film is formed, a raw mother block is obtained, and then the mother block is cut to obtain an individual multilayer ceramic capacitor 21. It is obtained by obtaining a plurality of raw component bodies and then firing the raw component bodies.

External electrodes 32 and 33 are formed on the component main body 22 obtained as described above. In forming the external electrodes 32 and 33, first, glass layers 40 and 41 are formed as shown in FIG. In order to form the glass layers 40 and 41, a glass paste is applied to the regions adjacent to the end surfaces 30 and 31 on the main surfaces 26 and 27 and the side surfaces of the component body 22 and baked. The glass paste is obtained by dispersing glass frit containing silicon oxide in a varnish obtained by dissolving an organic binder in an organic solvent.

The glass layers 40 and 41 are made of glass containing 23 mol% or more and 74 mol% or less of silicon oxide. Therefore, the glass constituting the glass frit contained in the glass paste described above has a composition that gives glass containing silicon oxide of 23 mol% or more and 74 mol% or less in the glass layers 40 and 41 obtained by baking. Have.

In addition, when the glass constituting the glass frit contained in the glass paste is, for example, Si—B—Zn-based, a part of zinc oxide, which is a glass component, is sublimated in the baking process, and thus obtained by baking. The ratio of silicon oxide in the glass layers 40 and 41 is higher than the ratio of silicon oxide contained in the glass contained in the glass paste. Therefore, considering this, the composition of the glass contained in the glass paste should be determined.

As shown in FIG. 2, the distance C from each of the end faces 30 and 31 of the component body 22 to the respective edges 42 and 43 of the glass layers 40 and 41 is between the pair of end faces 30 and 31 of the component body 22. The distance L is preferably in the range of 1/4 to 1/2 times the distance L.

Next, as shown in FIG. 3, external electrodes 32 and 33 are formed by baking a conductive paste. The conductive paste used here contains, for example, conductive metal powder such as Cu powder, glass frit, and varnish, and the content ratio of silicon oxide in the glass frit can be arbitrarily selected. The edges 34 and 35 of the external electrodes 32 and 33 are located so as to expose the edges 42 and 43 of the glass layers 40 and 41, respectively.

Note that the above-described baking of the glass layers 40 and 41 and the baking of the external electrodes 32 and 33 may be performed simultaneously.

Next, as shown in FIG. 1, the plating films 36 and 37 are formed on the external electrodes 32 and 33 by performing wet plating such as electrolytic plating. Since the glass constituting the glass layers 40 and 41 is not easily dissolved in the plating solution used in this plating process, the component main body 22 is eroded in the vicinity of the edges 34 and 35 of the external electrodes 32 and 33 in the plating process. And being vulnerable. Therefore, it is possible to advantageously suppress the occurrence of cracks starting from the portions where the edges 34 and 35 of the external electrodes 32 and 33 are located, and as a result, the mechanical strength of the multilayer ceramic capacitor 21 can be increased.

Next, Experimental Example 1 carried out to confirm the effect of the present invention based on the first embodiment will be described.

[Experimental Example 1]
(1) Production of component main body A plurality of ceramic green sheets containing ceramic material powders mainly composed of Ba and Ti were prepared. Next, on the ceramic green sheet, a conductive paste containing Ni as a main component was applied by screen printing to form a conductive paste film to be an internal electrode.

Next, the ceramic green sheets on which the conductive paste film is not formed are stacked so as to have a predetermined outer layer thickness, and then a predetermined number of ceramic green sheets on which the conductive paste film is formed are stacked. A green mother block in which a plurality of component main bodies can be taken out was obtained by laminating ceramic green sheets having no paste formed so as to have a predetermined outer layer thickness.

Next, the mother block was cut, a plurality of chip-shaped raw component bodies were taken out, and then the raw component bodies were fired in a reducing furnace in a reducing atmosphere to obtain a sintered component body.

(2) Formation of glass layer As shown in the column of “amount of silicon oxide in glass frit” in Table 1, the content of silicon oxide is 5 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol. %, 50 mol%, 60 mol%, 70 mol%, 80 mol% of glass frit (Si—B—Zn glass) and varnish are dispersed and mixed with three rolls to obtain a glass paste. It was. Here, the content of the glass frit in the glass paste was set in the range of 20 to 30% by volume. The varnish was prepared by dissolving an acrylic resin in an organic solvent containing terpineol as a main component.

Next, the above glass paste was printed on the main surface and the side surface of the component body adjacent to the end surface.

Next, the above glass paste was baked by heat treatment at 900 ° C. for 10 minutes in a nitrogen atmosphere to form a glass layer. Here, the distance C shown in FIG. 2 is set to be in a range of ¼ to ½ times the distance L.

(3) Formation of external electrode: Cu powder (D50 = 1.5 μm), glass frit made of Si—B—Zn glass at a softening point of 550 to 700 ° C., acrylic solvent in organic solvent mainly composed of terpineol A conductive paste for external electrodes was obtained by dispersing and mixing the varnish obtained by dissolving the resin. Here, the ratio of inorganic components (Cu powder and glass frit) in the conductive paste is 30% by volume, and the ratio of Cu powder and glass frit is 4: 1 to 6: 4 in volume ratio. I made it.

Next, a film made of the conductive paste for external electrodes is formed with a predetermined thickness on the surface plate, and after immersing the end of the component main body held by the holder in the conductive paste film, By taking out from the conductive paste film, a conductive paste to be an external electrode was applied to both end faces of the component main body. At this time, the position of the edge of the conductive paste film serving as the external electrode was adjusted so that the edge of the glass layer was exposed.

Next, in order to bake the conductive paste to be the external electrode, the component body was heat-treated in a belt furnace. In the heat treatment, the condition of holding the maximum temperature in the range of 900 ° C. for 10 minutes was adopted. Here, a reducing atmosphere was applied to prevent oxidation of the external electrode.

(4) Formation of plating film Ni electrolytic plating and Sn electrolytic plating were sequentially applied to the external electrode to form a plating film on the external electrode.

A multilayer ceramic capacitor serving as a sample was obtained as described above.

(5) Quantification of silicon oxide in the glass layer For the multilayer ceramic capacitor according to each sample, the glass layer is subjected to point analysis by XRF in the vicinity of the edge of the external electrode, thereby qualitatively and quantitatively determining the elements present there. analyzed.

From the elements found by this analysis, elements excluding Ba and Ti that are components of the ceramic layer, Cu that is a component of the external electrode, and Ni and Sn that are components of the plating film are used as the ends of the external electrode. The element of the glass component in the vicinity of the edge was converted into an oxide, and the “amount of silicon oxide in the glass layer” in Table 1 was quantified.

(6) Deflection test A multilayer ceramic capacitor according to each sample is mounted on a glass epoxy substrate with solder, a load is applied at a speed of 1.0 mm / sec, and the deflection amount is held for 5 ± 1 sec after reaching 1.5 mm. did.

Next, the multilayer ceramic capacitor after the above deflection test was subjected to cross-section polishing, the polished surface was observed to check for the occurrence of cracks, and the crack generation rate in 20 samples was calculated. The result is shown in the column of “crack rate” in Table 1.

In Table 1, when “the amount of silicon oxide in the glass frit” and “the amount of silicon oxide in the glass layer” are compared, when the glass paste is baked, one of the zinc oxides which are one of the glass components constituting the glass frit. Since the part sublimates, it can be seen that the “amount of silicon oxide in the glass layer” is larger than the “amount of silicon oxide in the glass frit”.

In the samples 1 and 2 whose “amount of silicon oxide in the glass layer” is 7 mol% and 14 mol%, cracks occurred in the deflection test. This is presumably because the glass was dissolved in the plating solution in the vicinity of the edge of the external electrode, and the component main body was eroded.

On the other hand, even in Sample 9 where the “silicon oxide content in the glass layer” was 84 mol%, cracks occurred in the deflection test. This is because the softening point of the glass was high and the glass was not sufficiently softened during baking, so the denseness of the glass layer was lowered, the function of blocking the plating solution was lowered, and the component body was eroded. It is guessed.

On the other hand, in the samples 3 to 8 in which the “amount of silicon oxide in the glass layer” was in the range of 23 to 74 mol%, no crack was generated in the deflection test. This is presumably because the glass of the glass layer has a composition that is difficult to dissolve in the plating solution, and thus the component main body was not eroded.

When the baking temperature of the glass paste for forming the glass layer is increased to 1000 ° C., the denseness of the glass layer is improved. However, when heat treatment is performed at such a high temperature, damage to the component body is large, and electrical characteristics are increased. Has been confirmed to decrease.

[Second Embodiment]
FIG. 4 is a view corresponding to FIG. 1 and shows a multilayer ceramic capacitor 51 according to a second embodiment of the present invention.

Referring to FIG. 4, a multilayer ceramic capacitor 51 includes a component body 22 that is substantially similar to the component body 22 provided in the multilayer ceramic capacitor 21 shown in FIG. Therefore, in FIG. 4, elements corresponding to those shown in FIG.

The first and second end surfaces 30 and 31 of the component body 22 are electrically connected to the end portions of the first and second internal electrodes 24 and 25, respectively. External electrodes 52 and 53 are formed. The first and second external electrodes 52 and 53 have respective end edges 54 and 55 located on the main surfaces 26 and 27 adjacent to the end surfaces 30 and 31 and on the side surfaces. External electrodes 52 and 53 are formed, for example, by baking a conductive paste mainly composed of copper.

The external electrodes 52 and 53 are arranged on the main surfaces 56 and 57 located on the end faces 30 and 31 of the component main body 22 and on the main surfaces 26 and 27 and the side surfaces of the component main body 22 depending on the silicon oxide content. 28 and 29 (see FIG. 7) are classified into adjacent surface extensions 58 and 59. Broadly speaking, the conductive paste used to form the adjacent surface extensions 58 and 59 has a relatively high silicon oxide content.

Plated films 36 and 37 are formed on the external electrodes 32 and 33, respectively. The plating films 36 and 37 are substantially the same as the plating films 36 and 37 in the multilayer ceramic capacitor 21 shown in FIG.

As a feature of the present invention, also in this embodiment, at least 23 mol% and 74 mol% on the surface of the component body 22 and at least from the edges 54 and 55 of the external electrodes 52 and 53 to the vicinity thereof. Glass regions 60 and 61 in which the following glass containing silicon oxide is present are formed. In this embodiment, the glass regions 60 and 61 are provided by glass components that have exuded from the conductive paste by baking the conductive paste applied to form the adjacent surface extensions 58 and 59 described above. .

Next, a method for manufacturing the multilayer ceramic capacitor 51 will be described.

First, the component body 22 is prepared.

On the other hand, as the conductive paste for forming the external electrodes 52 and 53, the conductive paste for the main portions 56 and 57 and the conductive paste for the adjacent surface extension portions 58 and 59 are prepared. Each of the conductive pastes contains conductive metal powder, glass frit, and varnish, but particularly the conductive paste for the adjacent surface extension portions 58 and 59 is 23 mol% or more and 74 mol as described above. The glass regions 60 and 61 in which glass containing less than 1% of silicon oxide is present are selected so as to be formed by the glass component exuded from the conductive paste.

Next, as shown in FIG. 5, the conductive paste for the adjacent surface extensions 58 and 59 is formed on the main surfaces 26 and 27 and the side surfaces 28 and 29 of the component body 22 in the region adjacent to the end surfaces 30 and 31. As a result, conductive paste films 62 and 63 to be adjacent surface extensions 58 and 59 are formed.

Next, a conductive paste for the main portions 56 and 57 is applied on the end faces 30 and 31 of the component body 22, thereby forming a conductive paste film to be the main portions 56 and 57. By performing the baking process, as shown in FIG. 6, external electrodes 52 and 53 comprising sintered adjacent surface extensions 58 and 59 and main portions 56 and 57 are formed.

Further, as a result of the baking process described above, the glass components ooze out from the adjacent surface extension portions 58 and 59, whereby glass regions 60 and 61 in which glass containing silicon oxide of 23 mol% or more and 74 mol% or less exists are provided. And formed on the surface of the component body 22 from at least the end edges 54 and 55 of the external electrodes 52 and 53 to the vicinity thereof.

As in the case of the first embodiment, when the glass contained in the conductive paste for forming the adjacent surface extension portions 58 and 59 is, for example, Si—B—Zn-based, in the baking step, Since a part of zinc oxide which is a glass component is sublimated, the ratio of silicon oxide in the glass regions 60 and 61 formed as a result of baking is higher than the ratio of silicon oxide contained in the glass in the conductive paste. Therefore, in consideration of this, the composition of the glass contained in the conductive paste should be determined.

As shown in FIG. 6, the distance D from the positions of the edges 54 and 55 of the external electrodes 52 and 53 to the edges 64 and 65 of the glass regions 60 and 61 is determined by the end face 30 of the component body 22. And 31 to the end edges 54 and 55 of each of the external electrodes 52 and 53 are preferably in the range of 1/10 to 1 times the distance E. In this embodiment, since the glass regions 60 and 61 are formed by the glass component exuded from the conductive paste, it is relatively difficult to visually determine the positions of the edges 64 and 65. is there. Therefore, in order to obtain the positions of the edges 64 and 65 of the glass regions 60 and 61, the following method is employed.

FIG. 7 shows a plan view of the structure in the state shown in FIG. When the Si concentration distribution is obtained by performing XRF line analysis along the line 66 shown in FIG. 7, an analysis result as shown in FIG. 8 is obtained. From the Si concentration gradient shown in FIG. 8, the length of the glass seepage, that is, the distance D between the “edge of the external electrode” and the “edge of the glass region” can be obtained.

In forming the external electrodes 52 and 53 as described above, the order of applying the conductive paste for the main portions 56 and 57 and the step of applying the conductive paste for the adjacent surface extension portions 58 and 59 are reversed. May be.

Next, as shown in FIG. 4, the plating films 36 and 37 are formed on the external electrodes 52 and 53 by performing wet plating such as electrolytic plating. Since the glass existing in the glass regions 60 and 61 is not easily dissolved in the plating solution used in this plating process, the component main body 22 is eroded in the vicinity of the edges 54 and 55 of the external electrodes 52 and 53 in the plating process. And being vulnerable. Therefore, it is possible to advantageously suppress the occurrence of cracks starting from the portions where the edges 54 and 55 of the external electrodes 52 and 53 are located, and as a result, the mechanical strength of the multilayer ceramic capacitor 21 can be increased.

Next, experimental example 2 conducted to confirm the effect of the present invention will be described based on the second embodiment.

[Experiment 2]
(1) Production of component body A component body similar to that in Experimental Example 1 was produced.

(2) Production of conductive paste for adjacent surface extension portion Cu powder (D50 = 1.D) as a conductive paste for the adjacent surface extension portion of the external electrode formed so as to go around the main surface and side surface of the component body. 5 μm), and as shown in the column of “amount of silicon oxide in glass frit” in Table 2, the content of silicon oxide is 5 mol%, 10 mol%, 20 mol%, 30 mol%, 40 mol%, 50 mol% A glass frit (Si—B—Zn glass) of mol%, 60 mol%, 70 mol%, and 80 mol%, respectively, and a varnish obtained by dissolving an acrylic resin in an organic solvent mainly composed of terpineol. A product obtained by dispersing and mixing was prepared.

(3) Production of conductive paste for main part As the conductive paste for the main part of the external electrode formed on the end face of the component body, the same as that prepared as the conductive paste for the external electrode in Experimental Example 1 Was made.

(4) Formation of external electrode The conductive paste for extending the adjacent surface was printed so as to circulate around the main surface and side surfaces of the component body, and the conductive paste for the main portion was printed on the end surface of the component body. .

Next, in order to bake the conductive paste for the adjacent surface extension portion and the main portion conductive paste, a baking step under the same conditions as the baking step for forming the external electrode in Experimental Example 1 is performed to form an external electrode. did.

(5) Measurement of spread of glass region During baking for forming the external electrode described above, the glass region is on the surface of the component main body due to the glass component exuded from the conductive paste for the adjacent surface extension portion, and the external electrode It was formed from the edge of the region to its vicinity.

As described above, the spread of the glass region is obtained by performing a line analysis with XRF along the line 66 shown in FIG. 7 to obtain a Si concentration distribution and obtaining an analysis result as shown in FIG. It can be obtained by observing the Si concentration gradient shown in FIG. In the sample obtained in Experimental Example 2, the distance D (see FIG. 6) from the position of the edge of the external electrode to the edge of the glass region measured is the distance from the end surface of the component body to the edge of the external electrode. It was confirmed that it was in the range of 1/10 to 1 times E (see FIG. 6).

(6) Formation of Plating Film As in the case of Experimental Example 1, Ni electrolytic plating and Sn electrolytic plating were sequentially applied to the external electrode to form a plating film on the external electrode.

A multilayer ceramic capacitor serving as a sample was obtained as described above.

(7) Quantification of silicon oxide in glass region By the same method as in Experimental Example 1, the amount of silicon oxide in the glass region was determined. The result is shown in the column of “amount of silicon oxide in the glass region” in Table 2.

(8) Deflection test A deflection test was carried out by the same method as in Experimental Example 1, and the “crack rate” in Table 2 was determined.

In Table 2, when “the amount of silicon oxide in the glass frit” is compared with “the amount of silicon oxide in the glass region”, one of the glass components constituting the glass frit is obtained by baking the conductive paste containing the glass frit. It can be seen that “amount of silicon oxide in the glass region” is larger than “amount of silicon oxide in the glass frit” because a part of the zinc oxide is sublimated.

In the samples 11 and 12 in which “the amount of silicon oxide in the glass region” was 7 mol% and 13 mol%, cracks occurred in the deflection test. This is presumably because the glass was dissolved in the plating solution in the vicinity of the edge of the external electrode, and the component main body was eroded.

On the other hand, even in the sample 19 in which the “amount of silicon oxide in the glass region” was 83 mol%, cracks occurred in the deflection test. This is because the glass softening point was high and the glass was not sufficiently softened during baking, so the glass region was not formed densely, the function of blocking the plating solution was not sufficient, and the component body was eroded. It is guessed.

On the other hand, in samples 13 to 18 in which the “amount of silicon oxide in the glass region” is in the range of 23 to 74 mol%, no crack was generated in the deflection test. This is presumably because the glass of the glass layer has a composition that is difficult to dissolve in the plating solution, and thus the component main body was not eroded.

[Other Embodiments]
When the multilayer ceramic electronic component according to the present invention is the multilayer ceramic capacitor 21 or 51 as shown in FIG. 1 or 4, the ceramic layer 23 is made of a dielectric ceramic. The multilayer ceramic electronic component to which the present invention is applied may be an inductor, a thermistor, a piezoelectric component, or the like. Therefore, according to the function of the multilayer ceramic electronic component, the ceramic layer may be composed of a dielectric ceramic, a magnetic ceramic, a semiconductor ceramic, a piezoelectric ceramic, or the like.

The illustrated multilayer ceramic capacitor 21 or 51 is of a two-terminal type including two external electrodes 32 and 33 or two external electrodes 52 and 53. However, the present invention is a multi-terminal multilayer ceramic electronic device. It can also be applied to parts.

Furthermore, the present invention can be applied not only to multilayer ceramic electronic components but also to single-layer type ceramic electronic components.

21, 51 Multilayer ceramic capacitor 22 Component body 23 Ceramic layers 24, 25 Internal electrodes 26, 27 Main surfaces 28, 29 Side surfaces 30, 31 End surfaces 32, 33, 52, 53 External electrodes 34, 35, 54, 55 Ends of external electrodes Edge 36, 37 Plated film 38, 39, 60, 61 Glass region 40, 41 Glass layer 42, 43 Edge 56, 57 of glass layer Main portion 58, 59 of external electrode Adjacent surface extension portion 62, 63 of external electrode Paste film 64, 65 Edge of glass region

Claims (7)

1. A substantially rectangular parallelepiped component body, which is configured with ceramic and has a pair of main surfaces facing each other, a pair of side surfaces facing each other, and a pair of end surfaces facing each other;
   It is formed by baking of a conductive paste containing a glass component, and is formed on the end surface of the component main body, and its end edge is on at least one of the main surface and the side surface adjacent to the end surface. An external electrode positioned at
   A plating film formed on the external electrode,
   A glass region is formed on the surface of the component main body, in which glass containing 23 mol% or more and 74 mol% or less of silicon oxide is present at least from the edge of the external electrode to the vicinity thereof.
   Ceramic electronic components.
2. The distance from the position of the said edge of the said external electrode to the edge of the said glass area | region measured below is the distance from the said end surface of the said component main body to the said edge of the said external electrode. Ceramic electronic components.
3. The glass region is formed by applying and baking a glass paste in which glass frit containing silicon oxide is dispersed in a region adjacent to the end surface on at least one of the main surface and the side surface of the component body. 3. The ceramic electronic component according to claim 1, wherein an edge of the external electrode is provided so as to expose an edge of the glass layer.
4. The distance from the end surface of the component body to the edge of the glass layer is in a range of ¼ to ½ times the distance between the pair of end surfaces of the component body. The ceramic electronic component described.
5. The glass region is a glass frit containing conductive metal powder and silicon oxide for forming a part of the external electrode in a region adjacent to the end surface on at least one of the main surface and the side surface of the component body. The ceramic electronic component according to claim 1, wherein the ceramic electronic component is provided by a glass component exuded from the conductive paste by applying and baking a conductive paste including:
6. The distance from the position of the edge of the external electrode to the edge of the glass region is in the range of 1/10 to 1 times the distance from the end surface of the component body to the edge of the external electrode. The ceramic electronic component according to claim 5.
7. The component main body includes a plurality of laminated ceramic layers and an internal electrode disposed along an interface between the ceramic layers, and an end portion of the internal electrode is exposed at the end surface, and the external electrode is The ceramic electronic component according to any one of claims 1 to 6, wherein the ceramic electronic component is connected to an end portion of the internal electrode exposed at the end face of the component main body.

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