Electronic component

Abstract

The electronic component includes a green body (20) and a glass film (50) covering an outer surface (21) of the green body (20). The glass film (50) has a groove (52) extending on an outer surface (51) of the glass film (50). The groove (52) is recessed from the outer surface (51) of the glass film (50) toward the outer surface (21) side of the green body (20) in a specific cross-section in a direction orthogonal to the outer surface (51) of the glass film (50). The bottom (52A) of the groove (52) is positioned further toward the outer surface (51) side of the glass film (50) than the outer surface (21) of the green body (20). In addition, the bottom (52A) of the groove (52) in a specific cross section is arc-shaped.

Description

Technical Field

[0001] The present disclosure relates to electronic components. Background Art

[0002] The invention described in Patent Document 1 comprises a body, an internal electrode, a glass layer, and an external electrode. The internal electrode is located inside the body. The glass layer covers the surface of the body. The glass layer has a plurality of through holes. The through holes extend from the outer surface of the glass layer to the boundary between the glass layer and the body. The external electrode is stacked on the outer surface of the glass layer. In addition, the external electrode is electrically connected to the internal electrode.

[0003] Patent Document 1: Japanese Patent No. 6680075

[0004] In an electronic component such as the invention described in Patent Document 1, basically, the greater the thickness of the glass layer, the greater the stress of the glass layer. On the other hand, in the case where the glass layer has a through hole as described in Patent Document 1, the stress of the glass layer is released in the through hole. Therefore, in the above-mentioned electronic component, it is possible to suppress the stress concentration at a specific position of the glass layer. However, the electronic component described in Patent Document 1 has a through hole in the glass layer, and the barrier property of the glass layer is reduced. Therefore, a structure that can alleviate the stress of the glass layer while suppressing the reduction in the barrier property of the glass layer is required. Summary of the invention

[0005] In order to solve the above-mentioned problems, one method of the present invention is an electronic component, comprising a blank and a glass film covering the outer surface of the blank, the glass film having: a groove extending on the outer surface of the glass film and being recessed from the outer surface of the glass film toward the outer surface of the blank in a specific cross-section in a direction perpendicular to the outer surface of the glass film, the bottom of the groove being located on the outer surface side of the glass film compared to the outer surface of the blank, and the bottom of the groove being arc-shaped in the specific cross-section.

[0006] According to the above configuration, it is possible to ensure the barrier properties of the glass film while suppressing stress concentration in the glass film. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Figure 1 It is a three-dimensional diagram of electronic components.

[0008] Figure 2 is a side view of an electronic component.

[0009] Figure 3 It is along Figure 2 Cross-sectional view along line 3-3.

[0010] Figure 4 This is an enlarged view of the outer surface of the glass film of the electronic component.

[0011] Figure 5 This is an enlarged view of the vicinity of the glass film when observing an electronic component at a specific cross section.

[0012] Figure 6 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0013] Figure 7 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0014] Figure 8 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0015] Fig. 9 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0016] Fig.10 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0017] Fig.11 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0018] Fig.12 This is an explanatory diagram for explaining a method for manufacturing an electronic component.

[0019] Fig.13 This is an enlarged view of the vicinity of the glass film when observing the electronic component of the modification example at a specific cross section. DETAILED DESCRIPTION

[0020] <One embodiment of electronic component>

[0021] Hereinafter, an embodiment of an electronic component will be described with reference to the accompanying drawings. It should be noted that in order to facilitate understanding, the components in the drawings are sometimes enlarged and shown. Sometimes the size ratio of the components is different from the actual size ratio or the size ratio in other drawings.

[0022] <About the overall structure>

[0023] like Figure 1 As shown, the electronic component 10 is, for example, a surface-mounted negative characteristic thermistor component mounted on a circuit board, etc. The negative characteristic thermistor component has a characteristic that the resistance value decreases when the temperature rises.

[0024] The electronic component 10 includes a blank 20. The blank 20 is roughly in the shape of a quadrangular prism and has a central axis CA. In addition, hereinafter, an axis extending along the central axis CA is set as a first axis X. In addition, an axis orthogonal to the first axis X is set as a second axis Y. In addition, an axis orthogonal to the first axis X and the second axis Y is set as a third axis Z. Furthermore, one direction along the first axis X is set as a first positive direction X1, and the direction opposite to the first positive direction X1 in the direction along the first axis X is set as a first negative direction X2. In addition, one direction along the second axis Y is set as a second positive direction Y1, and the direction opposite to the second positive direction Y1 in the direction along the second axis Y is set as a second negative direction Y2. Furthermore, one direction along the third axis Z is set as a third positive direction Z1, and the direction opposite to the third positive direction Z1 in the direction along the third axis Z is set as a third negative direction Z2.

[0025] The outer surface 21 of the blank 20 has six planes. In addition, the "face" of the blank 20 mentioned here refers to a face that can be observed as a face when observing the blank 20 as a whole. In other words, even if there are tiny bumps and steps that are not obvious if a part of the blank 20 is not magnified by a microscope, it is expressed as a plane or a curved surface. The six planes face different directions from each other. The six planes are roughly divided into a first end face 22A facing the first positive direction X1, a second end face 22B facing the first negative direction X2, and four side faces 22C. The four side faces 22C are respectively a face facing the third positive direction Z1, a face facing the third negative direction Z2, a face facing the second positive direction Y1, and a face facing the second negative direction Y2.

[0026] The boundary between two adjacent planes and the boundary between three adjacent planes in the outer surface 21 of the blank 20 are curved surfaces. That is, the corners of the blank 20 are R-chamfered. Figure 1 as well as Figure 2 In the drawings, the surface of a glass film 50 described later is regarded as the outer surface 21 of the body 20 and is given a reference numeral.

[0027] like Figure 2 As shown, the dimension of the blank 20 along the first axis X is larger than the dimension along the third axis Z. Figure 1 As shown, the dimension of the green body 20 along the first axis X is larger than the dimension along the second axis Y. The green body 20 is made of ceramics fired from a metal oxide containing one or more selected from Mn, Fe, Ni, Co, Ti, Ba, Al, and Zn as components.

[0028] like Figure 3As shown, the electronic component 10 includes two first internal electrodes 41 and two second internal electrodes 42 . The first internal electrodes 41 and the second internal electrodes 42 are buried in the base body 20 .

[0029] The material of the first internal electrode 41 is a conductive material. For example, the material of the first internal electrode 41 is palladium. The material of the second internal electrode 42 is the same as that of the first internal electrode 41.

[0030] The first internal electrode 41 has a rectangular plate shape. The main surface of the first internal electrode 41 is perpendicular to the second axis Y. The second internal electrode 42 has the same rectangular plate shape as the first internal electrode 41. The main surface of the second internal electrode 42 is perpendicular to the second axis Y as the first internal electrode 41.

[0031] The dimension of the first internal electrode 41 along the direction of the first axis X is smaller than the dimension of the body 20 along the direction of the first axis X. Figure 1 As shown, the dimension of the first inner electrode 41 along the third axis Z is approximately two thirds of the dimension of the body 20 along the third axis Z. The dimensions of the second inner electrode 42 in each direction are the same as those of the first inner electrode 41 .

[0032] like Figure 3 As shown in FIG. 2 , the first internal electrode 41 and the second internal electrode 42 are located at different positions in the direction along the second axis Y. That is, the first internal electrode 41, the second internal electrode 42, the first internal electrode 41, and the second internal electrode 42 are arranged in order from the side surface 22C facing the second positive direction Y1 toward the second negative direction Y2. In this embodiment, the distances between the internal electrodes in the direction along the second axis Y are equal.

[0033] like Figure 1 As shown, the two first internal electrodes 41 and the two second internal electrodes 42 are both located at the center of the blank 20 along the direction of the third axis Z. Figure 3 As shown, the first internal electrode 41 is located near the first positive direction X1, and the second internal electrode 42 is located near the first negative direction X2.

[0034] Specifically, the end of the first internal electrode 41 on the first positive direction X1 side coincides with the end of the blank 20 on the first positive direction X1 side. The end of the first internal electrode 41 on the first negative direction X2 side is located inside the blank 20 and does not reach the end of the blank 20 on the first negative direction X2 side. On the other hand, the end of the second internal electrode 42 on the first negative direction X2 side coincides with the end of the blank 20 on the first negative direction X2 side. The end of the second internal electrode 42 on the first positive direction X1 side is located inside the blank 20 and does not reach the end of the blank 20 on the first positive direction X1 side.

[0035] like Figure 3 As shown, the electronic component 10 includes a glass film 50. The glass film 50 covers the outer surface 21 of the blank 20. In the present embodiment, the glass film 50 covers the entire area of ​​the outer surface 21 of the blank 20. The main material of the glass film 50 is insulating glass. Therefore, the glass film 50 contains silicon dioxide. In addition, the glass film 50 contains one or more elements selected from alkali metals and alkaline earth metals as an additive. Specifically, the glass film 50 contains potassium as an additive. Therefore, in the element mapping image in the cross-sectional image of the glass film 50, there is a case where the glass film 50 has an interface due to the presence of potassium.

[0036] The electronic component 10 includes a first external electrode 61 and a second external electrode 62. The first external electrode 61 includes a first base electrode 61A and a first metal layer 61B. The first base electrode 61A includes a portion of the first end surface 22A on the outer surface 21 of the body 20 and is stacked from above the glass film 50. Specifically, the first base electrode 61A is a five-sided electrode that covers the first end surface 22A of the body 20 and a portion of the first positive direction X1 side of the four side surfaces 22C. In this embodiment, the material of the first base electrode 61A is silver and glass.

[0037] The first metal layer 61B covers the first base electrode 61A from the outside. Therefore, the first metal layer 61B is stacked on the first base electrode 61A. Although not shown in the figure, the first metal layer 61B has a two-layer structure of a nickel layer and a tin layer in this order from the first base electrode 61A side.

[0038] The second external electrode 62 includes a second base electrode 62A and a second metal layer 62B. The second base electrode 62A includes a portion of the second end surface 22B on the outer surface 21 of the body 20 and is stacked from above the glass film 50. Specifically, the second base electrode 62A is a five-sided electrode that covers the second end surface 22B and a portion of the first negative direction X2 side of the four side surfaces 22C of the body 20. In this embodiment, the material of the second base electrode 62A is the same as that of the first external electrode 61, which is a mixture of silver and glass.

[0039] The second metal layer 62B covers the second base electrode 62A from the outside. Therefore, the second metal layer 62B is stacked on the second base electrode 62A. Specifically, the second metal layer 62B has a double-layer structure of nickel plating and tin plating, similar to the first metal layer 61B.

[0040] The second external electrode 62 is arranged on the side surface 22C so as not to reach the first external electrode 61 and to be separated from the first external electrode 61 in the direction along the first axis X. In addition, on the side surface 22C of the body 20, the first external electrode 61 and the second external electrode 62 are not stacked in the central portion in the direction along the first axis X, and the glass film 50 is exposed. Figure 1 to Figure 3 In FIG. 1 , the first external electrode 61 and the second external electrode 62 are indicated by two-dot chain lines.

[0041] like Figure 3 As shown, the first external electrode 61 is connected to the end of the first internal electrode 41 on the first positive direction X1 side via the first extended protrusion 71 that penetrates the glass film 50. In addition, although it will be described in detail later, in the manufacturing process of the electronic component 10, the first extended protrusion 71 is formed by extending the palladium constituting the first internal electrode 41 toward the first external electrode 61 side.

[0042] In addition, the second external electrode 62 is connected to the end of the second internal electrode 42 on the first negative direction X2 side via a second extended protrusion 72 that penetrates the glass film 50. The second extended protrusion 72 is also formed by extending the palladium constituting the second internal electrode 42 toward the second external electrode 62 during the manufacturing process of the electronic component 10, similarly to the first extended protrusion 71. Figure 3 In the figure, the first internal electrode 41 and the first extended protrusion 71 are shown as different components with a boundary, but in fact there is no clear boundary between the two. This also applies to the second extended protrusion 72. Figure 1 as well as Figure 2 In the figure, the first extending protrusion 71 and the second extending protrusion 72 are omitted.

[0043] <About glass film>

[0044] like Figure 4 As shown in FIG. 1 , the glass film 50 has a groove 52 extending on the outer surface 51 of the glass film 50. It should be noted that the width of the opening edge 52B of the groove 52 on the outer surface 51 of the glass film 50, when viewed in a direction perpendicular to the outer surface 51 of the glass film 50, is defined as the opening width WG. At this time, when the extension length of the opening is five times or more relative to the opening width WG, it is defined as "the groove 52 extending on the outer surface 51 of the glass film 50".

[0045] like Figure 5As shown in FIG. 1 , a cross section of the glass film 50 in a direction perpendicular to the outer surface 51 is set as a specific cross section. In the specific cross section, the groove 52 is recessed from the outer surface 21 of the glass film 50 toward the outer surface 21 side of the blank 20. The bottom 52A of the groove 52 is located on the outer surface 51 side of the glass film 50 relative to the outer surface 21 of the blank 20. That is, the groove 52 does not penetrate the glass film 50.

[0046] The bottom 52A and the opening edge 52B of the groove 52 are determined as follows. First, the surface of the glass film 50 is photographed by an electron microscope. Then, a section processing is performed on an arbitrary specific section including the observed groove 52. Then, element mapping is performed on the specific section to obtain a mapping image in which the boundary with the blank 20 and the surface on the opposite side of the blank 20 in the glass film 50 are determined. In the mapping image, the lowest point TB closest to the outer surface 21 of the blank 20 in the groove 52 is determined. And, the area including a part of the lowest point TB is the bottom 52A.

[0047] In addition, in the specific cross section, as described above, a mapping image of the glass film 50 is acquired. Then, in the mapping image, a virtual line V is drawn that circumscribes any of the outer surfaces 51 of the glass film 50 on both sides of the groove 52. At this time, the virtual line V may also coincide with a portion of the outer surface 51 of the glass film 50. And, the end of the center side of the groove 52 among the contact points of the virtual line V and the outer surface 51 of the glass film 50 is set as the opening edge 52B.

[0048] In a specific cross section, the maximum depth SG of the groove 52 is about 750 nm. The maximum depth SG is the larger of the distances from the two opening edges 52B to the bottom point TB in a direction perpendicular to the above-mentioned virtual line V. In addition, in this embodiment, the opening width WG is about 870 nm. The opening width WG is the distance from one opening edge 52B to the other opening edge 52B on the virtual line V.

[0049] On a specific cross section, the bottom 52A of the groove 52 is in the shape of an arc. In other words, the area in the specific cross section that contains the lowest point TB and is in the shape of an arc is the bottom 52A. In addition, the "arc" mentioned here, for example, ignores tiny bumps less than 1nm that cannot be clearly determined in observation under an electron microscope, as long as it is in the shape of an arc as a whole. On a specific cross section, the radius of curvature R1 of the bottom 52A of the groove 52 is greater than 10nm. In the present embodiment, the radius of curvature R1 of the bottom 52A of the groove 52 is approximately 315nm. As mentioned above, the opening width WG of the groove 52 is approximately 870nm. Therefore, the radius of curvature R1 of the bottom 52A is greater than one-fourth of the opening width WG.

[0050] In addition, the curvature radius R1 of the bottom 52A is defined as follows. First, as described above, a mapping image of the glass film 50 including the bottom 52A is acquired. Then, in the mapping image, an arc approximating the surface of the bottom 52A is determined. Then, an approximate circle 52C including the arc is determined. The radius of the approximate circle 52C is set as the curvature radius R1.

[0051] In a specific cross section, a portion of the inner wall 52D of the groove 52 is in the shape of an arc. Specifically, a tangent line that is in contact with the inner wall 52D of the groove 52 and is inclined 45 degrees relative to the virtual line V is set as a specific tangent line SL. Moreover, the contact point between the specific tangent line SL and the inner wall 52D of the groove 52 is set as a specific contact point SP. At this time, a portion PP of the inner wall 52D of the groove 52 that includes the specific contact point SP becomes an arc. The curvature radius R2 of the portion PP that includes the specific contact point SP is greater than 10nm. In the present embodiment, the curvature radius R2 of the portion PP that includes the specific contact point SP is approximately 40nm to 60nm. In addition, in Figure 5 In the figure, the curvature radius R2 of one part PP is omitted.

[0052] <About the thickness of glass film>

[0053] like Figure 5 As shown, the shortest distance from the outer surface 21 of the blank 20 to the outer surface 51 of the glass film 50 is defined as the thickness TG of the glass film 50. The average value of the thickness TG of the glass film 50 at the position where the groove 52 does not exist is greater than 300 nm. Specifically, in the present embodiment, the average value of the thickness TG of the glass film 50 is approximately 850 nm. In addition, the average value of the thickness TG of the glass film 50 at the position where the groove 52 does not exist is calculated as follows.

[0054] First, a position where the groove 52 does not exist in the outer surface 51 of the glass film 50 is determined. Next, a specific cross section of the glass film 50 at this position is photographed by an electron microscope. For the photographed image, a range of at least 5 μm in the direction along the outer surface 51 of the glass film 50 is used as a measurement range. And, by image processing, the cross-sectional area of ​​the glass film 50 in the measurement range is calculated. Then, by dividing the cross-sectional area of ​​the glass film 50 in the measurement range by the length of the measurement range in the direction along the outer surface 51 of the glass film 50, the average value of the thickness TG of the glass film 50 is calculated. In other words, the average value of the thickness TG of the glass film 50 is the average value of the thickness TG in the measurement range.

[0055] In addition, in the specific cross section, the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the body 20 is about 90 nm. That is, in the specific cross section, the ratio of the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the body 20 to the average value of the thickness TG of the glass film 50 is 10% or more. In the present embodiment, the ratio is about 10.6%.

[0056] <Method for manufacturing electronic components>

[0057] Next, a method for manufacturing the electronic component 10 will be described.

[0058] like Figure 6 As shown, the method for manufacturing the electronic component 10 includes a laminate preparation step S11, an R chamfering step S12, a solvent introduction step S13, a catalyst introduction step S14, a green body introduction step S15, a polymer introduction step S16, and a metal alkoxide introduction step S17. In addition, the method for manufacturing the electronic component 10 also includes a film forming step S18, a drying step S19, an impregnation step S20, a sintering step S21, a conductor coating step S22, a curing step S23, and a plating step S24.

[0059] First, when forming the green body 20, in the stack preparation step S11, a stack of the green body 20 in the shape of a rectangular parallelepiped is prepared. That is, the stack at this stage is in a state before R chamfering is performed. For example, first, a plurality of ceramic sheets that will become the green body 20 are prepared. The sheet is in the shape of a relatively thin plate. A conductive paste that will become the first internal electrode 41 is stacked on the sheet. On the stacked paste, a ceramic sheet that will become the green body 20 is stacked. A conductive paste that will become the second internal electrode 42 is stacked on the sheet. In this way, ceramic sheets and conductive pastes are stacked. Then, an unfired stack is formed by cutting into a specified size. Thereafter, a stack is prepared by firing the unfired stack at a high temperature.

[0060] Next, if Figure 6 As shown, an R chamfering process S12 is performed. In the R chamfering process S12, a curved surface is formed at the boundary portion of two adjacent planes and the boundary portion of three adjacent planes of the laminate prepared in the laminate preparation process S11. For example, the corners of the laminate are R chamfered by roller grinding, so that a curved surface is formed at the above-mentioned boundary portion.

[0061] Next, if Figure 6 As shown, the solvent adding step S13 is performed. Figure 7 As shown, in the solvent adding step S13 , 2-propanol is added as the solvent 82 into the reaction container 81 .

[0062] Next, if Figure 6As shown, the catalyst feeding step S14 is performed. Figure 8 As shown, in the catalyst introduction step S14, first, stirring of the solvent 82 in the reaction container 81 is started. Then, ammonia water is introduced into the reaction container 81 as an aqueous solution 83 containing a catalyst. The catalyst in this embodiment is hydroxide ions, which function as a catalyst for promoting the hydrolysis of the metal alkoxide 85 described later.

[0063] Next, if Figure 6 As shown, the blank feeding step S15 is performed. Fig. 9 As shown, in the green body inserting step S15 , a plurality of green bodies 20 formed in advance in the R-chamfering step S12 as described above are inserted into the reaction container 81 .

[0064] Next, if Figure 6 As shown, the polymer feeding step S16 is performed. Fig.10 As shown, in the polymer adding step S16 , polyvinyl pyrrolidone is added into the reaction container 81 as the polymer 84 . Thus, the polymer 84 added into the reaction container 81 is adsorbed onto the outer surface 21 of the blank 20 .

[0065] Next, if Figure 6 As shown, the metal alkoxide adding step S17 is performed. Fig.11 As shown, in the metal alkoxide feeding step S17, liquid tetraethyl orthosilicate is fed into the reaction vessel 81 as the metal alkoxide 85. In addition, tetraethyl orthosilicate is sometimes referred to as tetraethoxysilane. In the present embodiment, the amount of the metal alkoxide 85 fed in the metal alkoxide feeding step S17 is calculated based on the area of ​​the outer surface 21 of the blank 20 fed in the blank feeding step S15. Specifically, the amount of the metal alkoxide 85 per blank 20 required to form the glass film 50 covering the outer surface 21 of the blank 20 is multiplied by the number of the blanks 20 for calculation.

[0066] Next, if Figure 6 As shown, a film forming step S18 is performed. In the film forming step S18, after the metal alkoxide 85 is added into the reaction vessel 81 by the metal alkoxide adding step S17, the stirring of the solvent 82 started in the above-mentioned solvent adding step S13 is continued for a predetermined time. Thus, the metal alkoxide 85 is hydrolyzed by the hydroxide ions serving as a catalyst. If the metal alkoxide 85 is hydrolyzed, the hydrolyzed metal alkoxide 85 adheres to the surface of the blank 20. Moreover, the metal alkoxide 85 attached to the surface of the blank 20 is dehydrated and condensed to form the glass film 50. In the film forming step S18, the sol-like glass film 50 is formed by a liquid phase reaction in the reaction vessel 81.

[0067] Next, if Figure 6As shown, a drying step S19 is performed. In the drying step S19, after the film forming step S18, the green body 20 is taken out from the reaction vessel 81 and dried. Thus, the sol-like glass film 50 is dried to become a gel-like glass film 50. In the drying step S19, cracks that penetrate the glass film 50 are generated. The cracks are cracks in the previous stage of forming the grooves 52 described later. In addition, by generating cracks, the stress of the glass film 50 is dispersed.

[0068] Next, if Figure 6 As shown, the impregnation step S20 is performed. Fig.12 As shown, in the immersion step S20, first, a solution 87 containing at least one element selected from alkali metals and alkaline earth metals as an additive is placed in advance in a reaction vessel 86 different from the reaction vessel 81 used until the film forming step S18. In this embodiment, the solution 87 is a solution containing a potassium oxide precursor. Then, the body 20 having the gel-like glass film 50 is immersed in the solution 87. As a result, the solution 87 is attached to the surface of the glass film 50. In addition, the melting point temperature of the glass film 50 is reduced.

[0069] Next, if Figure 6 As shown, the sintering step S21 is performed. In the sintering step S21, the blank 20 immersed in the solution 87 in the immersion step S20 is first taken out from the reaction container 86. Then, the taken blank 20 is fired in an atmosphere of 800 degrees for twenty minutes. As a result, the glass film 50 is melted. Moreover, a part of the melted glass film 50 penetrates into the inside of the crack generated in the drying step S19. As a result, the bottom 52A of the glass film 50 is formed on the outer surface 21 of the blank 20 exposed inside the crack of the glass film 50, and the groove 52 is formed. At this time, due to surface tension, the glass wets and rises at the position in contact with the wall of the crack. Therefore, the bottom 52A becomes an arc shape in a specific cross section. In addition, in the sintering step S21, the solvent of the solution 87 attached to the surface of the glass film 50 volatilizes. On the other hand, the potassium oxide precursor contained in the solution 87 is precipitated on the outer surface 51 of the glass film 50.

[0070] Next, the conductor coating step S22 is performed. In the conductor coating step S22, the conductor paste is coated on two locations on the surface of the glass film 50, including a portion of the portion covering the first end face 22A of the blank 20 and a portion of the portion covering the second end face 22B of the blank 20. Specifically, the conductor paste is coated on a portion of the first positive direction X1 side of the blank 20 including the entire area of ​​the first end face 22A to cover the glass film 50. In addition, the conductor paste is coated on a portion of the first negative direction X2 side of the blank 20 including the entire area of ​​the second end face 22B to cover the glass film 50.

[0071] Next, the curing step S23 is performed. Specifically, the curing step S23 heats the green body 20 coated with the glass film 50 and the conductive paste. As a result, the precipitated potassium oxide precursor becomes potassium oxide. Potassium oxide diffuses into the inside of the glass film 50 covering the outer surface 21 of the green body 20. In addition, water and polymer 84 are vaporized from the gel-like glass film 50, so that the sol covering a part of the outer surface 21 of the green body 20 is solidified. In addition, the conductive paste applied to the outer surface 21 of the green body 20 is solidified. That is, the first base electrode 61A and the second base electrode 62A are fired.

[0072] In the present embodiment, during heating in the curing step S23, palladium contained in the first internal electrode 41 side is attracted to the first base electrode 61A side containing silver by the Kirkendall effect caused by the difference in diffusion speed between the first internal electrode 41 and the first base electrode 61A. As a result, the first extended protrusion 71 extends from the first internal electrode 41 toward the first base electrode 61A through the glass film 50, and the first internal electrode 41 is connected to the first base electrode 61A. This is also the case with the second extended protrusion 72 connecting the second internal electrode 42 and the second base electrode 62A.

[0073] Next, the electroplating step S24 is performed. Electroplating is performed on the first base electrode 61A and the second base electrode 62A. Thus, the first metal layer 61B is formed on the surface of the first base electrode 61A. In addition, the second metal layer 62B is formed on the surface of the second base electrode 62A. Although not shown in the figure, the first metal layer 61B and the second metal layer 62B have a double-layer structure by electroplating with nickel and tin. In this way, the electronic component 10 is formed.

[0074] <Barrier test>

[0075] The barrier test was carried out on the blank 20 covered with the glass film 50 having the groove 52. In this test, five groups of samples were prepared, and a plurality of samples were prepared in each group. That is, a plurality of samples 1, 2, 3, 4, and 5 were prepared respectively. The glass film 50 was formed by carrying out the above-mentioned blank feeding step S15 to the sintering step S21. In addition, for each sample 1 to sample 5, the thickness TG of the glass film 50 of each sample group was different by changing the conditions of each step. Moreover, each sample was placed for 500 hours under the conditions of a temperature of 85 degrees and a relative humidity of 90 to 95%. Thereafter, the resistance value of each sample was measured. Moreover, the sample in which the degradation of the resistance value was observed was regarded as a defective product. In this test, the case where the resistance value was reduced by more than 0.1% relative to the resistance value before being exposed to the above-mentioned temperature and relative humidity conditions was judged as "degradation of the resistance value". For each sample group, each sample was judged whether it was the defective product, and the generation ratio of defective products in each group was calculated.

[0076] In sample 1, the average value of the thickness TG of the glass film 50 is 300 nm. In addition, the average value of the curvature radius R1 of the bottom 52A of the groove 52 of sample 1 is 540 nm. In addition, the average value of the curvature radius R2 of the part PP of the groove 52 of sample 1 is 130 nm. In sample 1, the generation rate of defective products is 0%.

[0077] In sample 2, the average value of the thickness TG of the glass film 50 is 850 nm. In addition, the average value of the curvature radius R1 of the bottom 52A of the groove 52 of sample 2 is 310 nm. In addition, the average value of the curvature radius R2 of the part PP of the groove 52 of sample 2 is 10 nm. In sample 2, the generation rate of defective products is 0%.

[0078] In sample 3, the average value of the thickness TG of the glass film 50 is 300 nm. In addition, the average value of the curvature radius R1 of the bottom 52A of the groove 52 of sample 3 is 10 nm. In addition, the average value of the curvature radius R2 of the part PP of the groove 52 of sample 3 is 40 nm. In sample 3, the generation rate of defective products is 0%.

[0079] In sample 4, the average value of the thickness TG of the glass film 50 is 100 nm. In addition, the average value of the curvature radius R1 of the bottom 52A of the groove 52 of sample 4 is 30 nm. In addition, the average value of the curvature radius R2 of the part PP of the groove 52 of sample 4 is 50 nm. In sample 4, the generation rate of defective products is 0.3%.

[0080] In sample 5, the average value of the thickness TG of the glass film 50 is 300 nm. In addition, the average value of the curvature radius R1 of the bottom 52A of the groove 52 of sample 5 is 3 nm. In addition, the average value of the curvature radius R2 of the part PP of the groove 52 of sample 5 is 8 nm. In sample 5, the generation rate of defective products is 0.2%.

[0081] In the case of sample 4, which produced defective products, the average value of the thickness TG of the glass film 50 was smaller than that of the other samples. In this case, it can be seen that the barrier properties are deteriorated compared with samples 1 to 3. In addition, in the case of sample 5, which produced defective products, the average value of the curvature radius R1 of the bottom 52A of the groove 52 was smaller than that of the other samples. In this case, it can also be seen that the barrier properties are deteriorated compared with samples 1 to 3. In addition, in sample 5, the average value of the curvature radius R2 of a part PP of the groove 52 was smaller than that of the other samples. In this case, it can also be seen that the barrier properties are deteriorated compared with the other samples 1 to 3.

[0082] According to the above test, it is preferable that the average value of the thickness TG of the glass film 50 is 300 nm or more, and it is preferable that the curvature radius R1 of the bottom 52A of the groove 52 is 10 nm or more. In addition, when the curvature radius R2 of the part PP of the groove 52 is large, it is difficult for other objects to be hooked near the opening edge 52B of the groove 52. In terms of suppressing such hooking and ensuring the characteristics of the product, it is preferable that the curvature radius R2 of the part PP of the groove 52 is 10 nm or more.

[0083] <Effects of the present embodiment>

[0084] (1) According to the above embodiment, since there is a groove 52 in the blank 20, the stress of the glass film 50 is released in the groove 52. Therefore, it is possible to prevent the stress from being concentrated at a specific position of the glass film 50. In addition, the groove 52 does not penetrate the glass film 50. In other words, the outer surface 21 of the blank 20 is not exposed inside the groove 52. Therefore, according to the above structure, the barrier property of the glass film 50 is ensured. In addition, the bottom 52A of the groove 52 is arc-shaped. Therefore, it is possible to prevent the groove 52 from extending toward the outer surface 21 side of the blank 20. That is, it is also possible to prevent the groove 52 from accidentally reaching the blank 20, which would damage the barrier property of the glass film 50.

[0085] (2) In the above embodiment, the curvature radius R1 of the bottom 52A of the groove 52 is 10 nm or more in the specific cross section. With this arc size, the curvature of the bottom 52A of the groove 52 can be ensured to a certain extent. Therefore, the effect described in (1) can be fully obtained.

[0086] (3) In the above embodiment, in a specific cross section, the curvature radius R1 of the bottom 52A of the groove 52 is greater than or equal to one-fourth of the opening width WG of the opening edge 52B of the groove 52. In other words, the arc shape of the bottom 52A in the above embodiment is the same as the arc shape of the bottom 52A when the groove 52 is assumed to be semicircular, and is a sufficiently gentle arc. If the arc of the bottom 52A is gentle in this way, for example, even when an external force acts on the glass film 50, it is possible to appropriately prevent the groove 52 from developing from the bottom 52A as a starting point.

[0087] (4) In the above-mentioned embodiment, a portion PP including a specific contact point SP in the inner wall 52D of the groove 52 is in an arc shape. Moreover, the radius of curvature R2 of the portion PP is greater than 10 nm. Here, the specific contact point SP in the above-mentioned inner wall 52D is a position where the inclination of the groove 52 suddenly changes to more than 45 degrees. Therefore, the position corresponding to the specific contact point SP is a position where other objects are easily hooked when they rub against the electronic component 10. Regarding this point, as described above, since a portion PP including the specific contact point SP is rounded, other objects are not easily hooked at the position corresponding to the specific contact point SP of the groove 52. By suppressing such hooking, the scratch resistance of the glass film 50 is improved.

[0088] (5) In the above embodiment, the average value of the thickness TG of the glass film 50 at the position where the groove 52 does not exist is 300 nm or more. According to this structure, the barrier property of the glass film 50 can be sufficiently ensured.

[0089] (6) In the above embodiment, when observing a specific cross section, the ratio of the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the body 20 to the average value of the thickness TG of the glass film 50 is 10% or more. According to this structure, even at the thinnest position of the glass film 50, the corresponding film thickness of the glass film 50 can be ensured. In other words, the barrier property of the glass film 50 can be ensured.

[0090] <Change Example>

[0091] The above-described embodiment and the following modified examples can be implemented in combination with each other within the scope of no technical contradiction.

[0092] The electronic component 10 is not limited to a negative characteristic thermistor component, and may be, for example, a multilayer capacitor component or an inductor component.

[0093] The material of the green body 20 is not limited to the example of the above embodiment. The material of the green body 20 may be a composite of resin and metal powder.

[0094] The shape of the blank 20 is not limited to the example of the above embodiment. For example, the blank 20 may be a polygonal column other than a quadrilateral column having a central axis CA. In addition, the blank 20 may be a core of a winding type inductor component. For example, the core may be a so-called drum core shape. Specifically, the core may have a columnar winding core portion and flange portions provided at each end of the winding core portion.

[0095] The boundary portion between adjacent planes in the outer surface 21 of the blank 20 does not need to be chamfered. In this case, there is no curved surface in the boundary portion.

[0096] The shapes of the first internal electrode 41 and the second internal electrode 42 may be any shapes as long as they can ensure electrical conduction with the corresponding first external electrode 61 and the second external electrode 62. In addition, regardless of the number of the first internal electrode 41 and the second internal electrode 42, the number of internal electrodes may be one or three or more.

[0097] The structure of the first external electrode 61 is not limited to the example of the above embodiment. For example, the first external electrode 61 may be composed of only the first base electrode 61A, and the first metal layer 61B may not have a double-layer structure. This also applies to the second external electrode 62 .

[0098] The combination of materials of the first internal electrode 41 and the first base electrode 61A is not limited to the combination of palladium and silver. For example, it may be a combination of copper and nickel, copper and silver, silver and gold, nickel and cobalt, or nickel and gold. Another example is a combination of silver on one side and silver and palladium on the other side. Another example is a combination of palladium on one side and silver and palladium on the other side, or a combination of copper on one side and silver and palladium on the other side. Another example is a combination of gold on one side and silver and palladium on the other side.

[0099] · In addition, depending on the combination of the first internal electrode 41 and the first base electrode 61A, there may be a case where the Kirkendall effect cannot be obtained. In this case, before the conductor coating step S22, the first internal electrode 41 may be processed so as to be exposed from the glass film 50. For example, the glass film 50 on the first end face 22A side of the blank 20 may be polished to physically remove a portion of the glass film 50. Thereafter, the first internal electrode 41 and the first base electrode 61A can be connected by performing the conductor coating step S22. In addition, for example, after the first base electrode 61A is formed, the glass film 50 may also be formed on the surface of the first base electrode 61A, and the glass film 50 covering the surface of the first base electrode 61A may be removed. This is also the same in the combination of the materials of the second internal electrode 42 and the second base electrode 62A.

[0100] The arrangement position of the first external electrode 61 is not limited to the example of the above embodiment. For example, the first external electrode 61 may be arranged only on the first end surface 22A and one side surface 22C. This also applies to the second external electrode 62 .

[0101] In the specific cross section of the above embodiment, the curvature radius R1 of the bottom 52A of the groove 52 may be less than 10 nm. As long as at least the bottom 52A is in an arc shape, the effect described in (1) can be expected.

[0102] In the specific cross section of the above embodiment, the curvature radius R2 of a portion PP including the specific contact point SP in the inner wall 52D of the groove 52 may be smaller than 10 nm. In addition, the portion PP may not be in an arc shape.

[0103] In the above embodiment, a portion of the glass film 50 including the opening edge 52B may be in an arc shape. Fig.13 In the example shown, the glass film 50 has a groove 52 extending on the outer surface 51 of the glass film 50. A section in a direction perpendicular to the outer surface 51 of the glass film 50 is set as a specific section. In the specific section, the groove 52 is recessed from the outer surface 21 of the glass film 50 toward the outer surface 21 of the blank 20. The bottom 52A of the groove 52 is located on the outer surface 51 side of the glass film 50 compared to the outer surface 21 of the blank 20. In other words, the groove 52 does not penetrate the glass film 50. In the specific section, the bottom 52A of the groove 52 is arc-shaped. Fig.13 In the example shown, the curvature radius R1 of the bottom 52A of the groove 52 is approximately 1 μm.

[0104] exist Fig.13 In the example shown, in a specific cross section, a portion PQ of the groove 52 including the opening edge 52B is arc-shaped. Specifically, the portion PQ is arc-shaped and convex toward the opposite side of the blank 20. The curvature radius of the portion PQ is greater than 10 nm. Fig.13 In the example shown, the radius of curvature of the arc of a portion of PQ is approximately 10 to 30 nm.

[0105] In addition, Fig.13 In the example shown, the opening width WG of the opening edge 52B of the groove 52 in the specific cross section is about 1.2 μm. That is, the curvature radius R1 of the bottom 52A of the groove 52 in the specific cross section is more than one quarter of the opening width WG of the opening edge 52B of the groove 52.

[0106] In addition, if Fig.13As in the example shown in the figure, on a specific cross section, a first virtual line V1 connecting the opening edges 52B on both sides of the groove 52 is drawn. Moreover, the position where the maximum depth SG of the groove 52 is half is set as the middle position MP, and a second virtual line V2 passing through the middle position MP and parallel to the first virtual line V1 is drawn. It is preferred that on a specific cross section, the value obtained by doubling the radius of curvature R1 of the bottom 52A of the groove 52 is greater than the length of the second virtual line V2 divided by the inner wall 52D of the groove 52 on the specific cross section. According to such a structure, the arc of the bottom 52A of the groove 52 is larger than the scale of the opening width WG of the groove 52. Therefore, at the bottom 52A of the groove 52, the stress is fully dispersed at the bottom 52A of the glass film 50. In addition, although not shown in the figure, in the above embodiment, the value obtained by doubling the radius of curvature R1 of the bottom 52A of the groove 52 is also greater than the length of the second virtual line V2 divided by the inner wall 52D of the groove 52 on the specific cross section.

[0107] In the above embodiment, the average value of the thickness TG of the glass film 50 at the position where the groove 52 does not exist may be less than 300 nm. In addition, in a specific cross section, the ratio of the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the body 20 to the average value of the thickness TG of the glass film 50 may be less than 10%. In other words, the bottom 52A of the groove 52 only needs to be located on the outer surface 51 side of the glass film 50 relative to the outer surface 21 of the body 20.

[0108] The structure of the glass film 50 is not limited to the above-mentioned embodiment. For example, it may not cover the entire area of ​​the outer surface 21 of the body 20. The range covered by the glass film 50 may be appropriately changed according to the shape of the body 20, the positions of the first external electrode 61 and the second external electrode 62, etc.

[0109] The glass contained in the glass film 50 may diffuse into the first underlying electrode 61A, so that the glass film 50 and the first underlying electrode 61A may be integrated. This is also the case with the glass film 50 and the second underlying electrode 62A.

[0110] The glass film 50 may not contain one or more elements selected from alkali metals and alkaline earth metals as additives.

[0111] The material of the glass film 50 is not limited to the examples of the above-mentioned embodiments. For example, glass is not limited to silicon dioxide, and may be a multi-component oxide containing Si, such as B-Si, Si-Zn, Zr-Si, and Al-Si oxides. In addition, glass may be a multi-component oxide containing alkali metals and Si, such as Al-Si, Na-Si, and Li-Si oxides. Furthermore, glass may be a multi-component oxide containing alkaline earth metals and Si, such as Mg-Si, Ca-Si, Ba-Si, and Sr-Si. Furthermore, glass may not contain Si, and may be a mixture of these materials.

[0112] The material of the glass film 50 may include, in addition to glass, a pigment, a silicone flame retardant, a silane coupling material, a titanate coupling agent or other surface treatment agent or an antistatic agent.

[0113] More specifically, in addition to glass, the glass film 50 may contain additives such as organic acid salts, oxides, inorganic salts, organic salts, and other metal oxide microparticles and nanoparticles. The additive contained in the solution 87 is not limited to the potassium oxide precursor.

[0114] Examples of the organic acid salt include oxyacid salts such as soda ash, sodium carbonate, sodium bicarbonate, sodium percarbonate, sodium sulfite, sodium bisulfite, sodium sulfate, sodium thiosulfate, sodium nitrate, and sodium sulfite, and halides such as sodium fluoride, sodium chloride, sodium bromide, and sodium iodide.

[0115] As an oxide, sodium peroxide can be mentioned, for example, and as a hydroxide, sodium hydroxide can be mentioned, for example.

[0116] Examples of the inorganic salt include sodium hydride, sodium sulfide, sodium hydrogen sulfide, sodium silicate, trisodium phosphate, sodium borate, sodium borohydride, sodium cyanide, sodium cyanate, and sodium tetrachloroaurate.

[0117] Inorganic salts include calcium peroxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium hydride, calcium carbide, and calcium phosphide.

[0118] The additive may be calcium carbonate, calcium hydrogen carbonate, calcium nitrate, calcium sulfate, calcium sulfite, calcium silicate, calcium phosphate, calcium pyrophosphate, calcium hypochlorite, calcium chlorate, calcium perchlorate, calcium bromate, calcium iodate, calcium arsenite, calcium chromate, calcium tungstate, calcium molybdate, calcium magnesium carbonate, hydroxyapatite or the like. In addition, the additive may include calcium acetate, calcium gluconate, calcium citrate, calcium malate, calcium lactate, calcium benzoate, calcium stearate, and calcium aspartate.

[0119] In addition, for example, the additive can also be lithium carbonate, lithium chloride, lithium titanate, lithium nitride, lithium peroxide, lithium citrate, lithium fluoride, lithium hexafluorophosphate, lithium acetate, lithium iodide, lithium hypochlorite, lithium tetraborate, lithium bromide, lithium nitrate, lithium hydroxide, lithium aluminum hydride, lithium triethylborohydride, lithium hydride, lithium amide, lithium imide, lithium diisopropylamide, lithium tetramethylpiperidinium, lithium sulfide, lithium sulfate, lithium thiophenol, and lithium phenol.

[0120] In addition, for example, the additive may be boron triiodide, sodium cyanoborohydride, sodium borohydride, tetrafluoroboric acid, triethylborane, borax, or boric acid.

[0121] In addition, the additive may be barium sulfite, barium chloride, barium chlorate, barium perchlorate, barium peroxide, barium chromate, barium acetate, barium cyanide, barium bromide, barium oxalate, barium nitrate, barium hydroxide, barium hydride, barium carbonate, barium iodide, barium sulfide, barium sulfate. In addition, the additive may be sodium acetate or sodium citrate.

[0122] Furthermore, the additive may be fine particles or nanoparticles of metal oxides. Examples of the metal oxides include sodium oxide, calcium oxide, lithium oxide, boron oxide, barium oxide, silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, zinc oxide, and magnesium oxide.

[0123] In addition, in the above embodiment, the potassium oxide precursor can be exemplified by potassium arsenide, potassium bromide, potassium carbide, potassium chloride, potassium fluoride, potassium hydride, potassium iodide, potassium triiodide, potassium azide, potassium nitride, potassium superoxide, potassium ozonide, potassium peroxide, potassium phosphide, potassium sulfide, potassium selenide, potassium telluride, potassium tetrafluoroaluminate, potassium tetrafluoroborate, potassium tetrahydroborate, potassium methanide, potassium cyanide, potassium formate, potassium hydrogen fluoride, potassium tetraiodomercurate (II), potassium hydrogen sulfide, potassium octachlorodimolybdate (II), potassium amide, potassium hydroxide, potassium hexafluorophosphate, potassium carbonate, potassium tetrachloroplatinate (II), potassium hexachloroplatinate (IV), potassium nonahydrorhenate (VII), potassium sulfate, potassium acetate, potassium cyanide gold (I), potassium hexanitrocobalt (III) acid, potassium hexacyanoferrate (III), hexacyanoferrate (III), potassium ... Potassium ferrocyanide (II) salt, potassium methoxide, potassium ethoxide, potassium tert-butoxide, potassium cyanate, potassium fulminate, potassium thiocyanate, potassium aluminum sulfate, potassium aluminate, potassium arsenate, potassium bromate, potassium hypochlorite, potassium chlorite, potassium chlorate, potassium perchlorate, potassium carbonate, potassium chromate, potassium dichromate, potassium tetraperoxychromate (V), potassium cuprate (III), potassium ferrate, potassium iodate, potassium periodate, potassium permanganate, potassium manganate, potassium hypomanganate, potassium molybdate, potassium nitrite, potassium nitrate, tripotassium phosphate, potassium perrhenate, potassium selenate, potassium silicate, potassium sulfite, potassium sulfate, potassium thiosulfate, potassium pyrosulfite, potassium dithionate, potassium disulfate, potassium peroxodisulfate, potassium dihydrogen arsenate, dipotassium hydrogen arsenate, potassium bicarbonate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium hydrogen selenate, potassium bisulfite, potassium hydrogen sulfate, potassium peroxodisulfate.

[0124] The metal alkoxide 85 may be, for example, sodium methoxide, sodium ethoxide, calcium diethoxide, lithium isopropoxide, lithium ethoxide, lithium tert-butoxide, lithium methoxide, boroalkoxide, potassium tert-butoxide, tetraethyl orthosilicate, allyl trimethoxysilane, isobutyl (trimethoxy) silane, tetrapropyl orthosilicate, tetramethyl orthosilicate, [3-(diethylamino)propyl]trimethoxysilane, triethoxy (octyl) silane, triethoxyvinyl silane, triethoxyphenyl silane, trimethoxyphenyl silane, trimethoxymethyl silane, butyl trichlorosilane, n-propyl triethoxysilane, methyl trichlorosilane, dimethoxy (methyl) octyl silane, dimethoxydimethyl silane, tri-tert-butyloxysilanol, tri-tert-pentyloxysilanol, hexadecyl trimethoxysilane, tri( 1,2-Benzenediolate-O,O') dipotassium silicate, tetrabutyl orthosilicate, aluminum silicate, calcium silicate, tetramethylammonium silicate solution, chlorotriisopropoxytitanium (IV), titanium (IV) isopropoxide, 2-ethylhexyl titanium (IV), titanium (IV) ethoxide, titanium (IV) butoxide, titanium (IV) tert-butoxide, titanium (IV) propoxide, titanium (IV) methoxide, zirconium (IV) bis(diethylcitrate) dipropoxide, zirconium (IV) bis(2,4-pentanedione) dibutoxide, zirconium (IV) 2-ethylhexanoate, zirconium (IV) isopropoxide-isopropanol complex, zirconium (IV) ethoxide, zirconium (IV) butoxide, zirconium (IV) tert-butoxide, zirconium (IV) propoxide, aluminum tert-butoxide, aluminum isopropoxide, aluminum ethoxide, aluminum tri-sec-butoxide, and aluminum phenolate.

[0125] In the above embodiment, the manufacturing method of the electronic component 10 may be a method different from that in the above embodiment. For example, the glass film 50 may be formed by the following method. First, a thin film that becomes the basis of the glass film 50 is formed on the outer surface 21 of the chamfered blank 20 by a drum spray method or the like. Then, the glass film 50 is formed by adding an additive containing at least one element selected from alkali metals and alkaline earth metals to the thin film.

[0126] The solvent 82 introduced in the solvent introduction step S13 is not limited to the example of the above-mentioned embodiment, and may be any liquid as long as the metal alkoxide 85 can be dispersed accordingly.

[0127] The solvent adding step S13 may be performed after the catalyst adding step S14 or the green body adding step S15. The solvent adding step S13 may be performed before at least one of the metal alkoxide adding step S17 and the catalyst adding step S14. In addition, the solvent adding step S13 may be omitted. In this case, for example, if the amount of water contained in the aqueous solution 83 containing the catalyst is relatively large, the metal alkoxide 85 reacts in the liquid phase. In addition, the aqueous solution 83 containing the catalyst may be added in a state mixed with an organic solvent as the solvent 82.

[0128] Although the aqueous solution 83 containing the catalyst is ammonia water and the catalyst is hydroxide ions, the catalyst is not limited thereto. As long as it is an alkaline aqueous solution, it can catalyze the hydrolysis of the metal alkoxide 85, just like the ammonia water in the above embodiment, and even an acidic aqueous solution can catalyze the hydrolysis of the metal alkoxide 85. Furthermore, even a neutral aqueous solution can be used as long as the aqueous solution contains ions that can catalyze hydrolysis.

[0129] Although the case where the catalyst is added as the aqueous solution 83 containing the catalyst has been described, a solid compound containing the catalyst and water may be added separately to the reaction container 81. In this case, the catalyst is generated in the reaction container 81, and it is considered that the catalyst is added to the reaction container 81. Alternatively, for example, a solid compound containing the catalyst may be added to the reaction container 81, and moisture in the air may be used as water required for hydrolysis.

[0130] The green body inserting step S15 may be performed before the catalyst inserting step S14. In addition, when the green body inserting step S15 is performed before the catalyst inserting step S14, the metal alkoxide inserting step S17 may be performed before the catalyst inserting step S14 or the green body inserting step S15. The green body inserting step S15 may be performed before at least one of the metal alkoxide inserting step S17 and the catalyst inserting step S14.

[0131] In the manufacturing method of the electronic component 10 of the above-mentioned embodiment, a solution containing a precursor for generating the metal alkoxide 85 may be added instead of the metal alkoxide 85. In this case, in the metal alkoxide adding step S17, it is sufficient to add a metal complex or acetate as a metal alkoxide precursor. As the metal complex, for example, acetylacetone such as lithium acetylacetonate, acetylacetonato titanium (IV), diisopropoxybis(acetylacetonato)titanium, trifluoroacetylacetonato zirconium (IV), acetylacetonato zirconium (IV), triacetylacetonato aluminum, acetylacetonato aluminum (III), acetylacetonato calcium (II), and acetylacetonato zinc (II) can be listed. In addition, as the acetate, for example, zirconium acetate, zirconium (IV) hydroxide acetate, and basic aluminum acetate can be listed.

[0132] Even if the metal alkoxide 85 is not generated outside the reaction container 81 and then added to the reaction container 81, the metal alkoxide adding step S17 can generate the metal alkoxide 85 in the reaction container 81. For example, the metal alkoxide 85 is generated by reacting a metal salt with ethanol. Therefore, even if a metal salt and ethanol, which are metal alkoxide precursors, are added to the reaction container 81 and the metal alkoxide 85 is generated by reacting them, it can be regarded that the metal alkoxide 85 is added to the reaction container 81.

[0133] The metal alkoxide 85 is not limited to tetraethyl orthosilicate. For example, the metal contained in the metal alkoxide 85 may be titanium, zirconium, aluminum, etc. In addition, if the metal contained in the metal alkoxide 85 is silicon, the reaction rate is slower than that of other metals, so it is easy to control the reaction rate of the metal alkoxide 85 constantly. In addition, the alkoxy group of the metal alkoxide 85 may be a methoxy group or a propoxy group, or may be decorated with a functional group such as a long-chain alkyl group or an epoxy group as a coupling agent. In addition, the coordination number of the metal contained in the metal alkoxide 85 is not limited to 4 coordinations, and may be 3 coordinations or 2 coordinations.

[0134] The reaction container 81 used in the immersion step S20 and the reaction container 86 used in the film formation step S18 do not need to be different.

[0135] In the immersion step S20, the solution 87 only needs to be attached to the glass film 50 covering the outer surface 21 of the body 20, and the entire body 20 does not need to be immersed in the solution 87 in the reaction container 86. For example, the solution 87 may be applied only to the portion of the outer surface 21 of the body 20 covered by the glass film 50. In addition, the method of adding the alkali metal and the alkaline earth metal to the gel-like glass film 50 is not limited to the immersion method, and the addition may be performed by spraying or the like.

[0136] The curing step S23 is not limited to a step of curing the glass film 50 and the conductive paste simultaneously. For example, if the conductive paste is a material that is cured by ultraviolet irradiation, a heating step may be performed as a step of curing the glass film 50 and ultraviolet irradiation may be performed as a step of curing the conductive paste.

[0137] In the above embodiment, after the drying step S19 is performed once from the blank inserting step S15 , the drying step S19 may be repeatedly performed again from the blank inserting step S15 . By repeatedly performing these steps, the thickness TG of the glass film 50 increases.

[0138] In the above embodiment, after the impregnation step S20 and the sintering step S21 are performed once, the impregnation step S20 and the sintering step S21 may be repeated again. By repeating these steps, the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the green body 20 increases, and the curvature radius R1 of the bottom 52A changes.

[0139] <Note>

[0140] The following describes technical ideas derived from the above-mentioned embodiments and modified examples.

[0141] [1] An electronic component comprising a body and a glass film covering the outer surface of the body, the glass film having a groove extending on the outer surface of the glass film and recessed from the outer surface of the glass film toward the outer surface of the body in a specific cross section in a direction perpendicular to the outer surface of the glass film, the bottom of the groove being located on the outer surface side of the glass film relative to the outer surface of the body, and the bottom of the groove being arc-shaped in the specific cross section.

[0142] [2] The electronic component according to [1], wherein in the specific cross section, the radius of curvature of the bottom of the groove is greater than or equal to 10 nm.

[0143] [3] The electronic component according to [1] or [2], wherein in the specific cross section, the radius of curvature of the bottom of the groove is greater than or equal to one quarter of the width of the opening edge of the groove.

[0144] [4] According to any one of the electronic components described in [1] to [3], in the above-mentioned specific cross-section, a line connecting the opening edges on both sides of the above-mentioned groove is set as a virtual line, a tangent line connected to the inner wall of the above-mentioned groove and inclined at 45 degrees relative to the above-mentioned virtual line is set as a specific tangent line, and a contact point between the above-mentioned specific tangent line and the inner wall of the above-mentioned groove is set as a specific contact point. In the above-mentioned specific cross-section, a part of the inner wall of the above-mentioned groove including the above-mentioned specific contact point becomes an arc shape, and the curvature radius of the above-mentioned part is greater than 10nm.

[0145] [5] The electronic component according to any one of [1] to [4], wherein the average value of the thickness of the glass film at a position where the groove does not exist is 300 nm or more.

[0146] [6] According to any one of [1] to [5], in the electronic component described in the above-mentioned specific cross-section, the ratio of the shortest distance from the bottom of the above-mentioned groove to the outer surface of the above-mentioned body to the average value of the thickness of the above-mentioned glass film is greater than 10%.

[0147] Description of Reference Numerals

[0148] 10 ... electronic component, 20 ... body, 21 ... outer surface, 50 ... glass film, 51 ... outer surface, 52 ... groove, 52A ... bottom, 52B ... opening edge.

Claims

1. An electronic component, wherein: A base body and a glass film covering the outer surface of the base body. The glass film has a groove extending on the outer surface of the glass film and recessed from the outer surface of the glass film toward the outer surface of the body in a specific cross section in a direction perpendicular to the outer surface of the glass film. The bottom of the groove is located closer to the outer surface of the glass film than the outer surface of the body, and the bottom of the groove is arc-shaped in the specific cross section.

2. The electronic component according to claim 1, wherein In the specific cross section, the radius of curvature of the bottom of the groove is greater than or equal to 10 nm.

3. The electronic component according to claim 1 or claim 2, wherein: In the specific cross section, the radius of curvature of the bottom of the groove is greater than or equal to one quarter of the width of the opening edge of the groove.

4. The electronic component according to any one of claims 1 to 3, wherein: On the specific cross section, a line connecting the opening edges on both sides of the groove is set as a virtual line. A tangent line that touches the inner wall of the groove and is inclined at 45 degrees with respect to the virtual line is set as a specific tangent line. When the contact point between the specific tangent line and the inner wall of the groove is set as the specific contact point, In the above-mentioned specific cross section, a portion of the inner wall of the above-mentioned groove including the above-mentioned specific contact point is in an arc shape. The radius of curvature of the above-mentioned portion is greater than 10 nm.

5. The electronic component according to any one of claims 1 to 4, wherein: The average value of the thickness of the glass film at a position where the groove does not exist is 300 nm or more.

6. The electronic component according to any one of claims 1 to 5, wherein: In the specific cross section, a ratio of the shortest distance from the bottom of the groove to the outer surface of the body to an average value of the thickness of the glass film is 10% or more.

Images