Electronic component

Abstract

This electronic component comprises an element body (20), and a glass film (50) which covers an outer surface (21) of the element body (20). The glass film (50) has a groove (52) that extends 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 element body (20) in a specific cross-section in a direction orthogonal to the outer surface (51) of the glass film (50). A bottom (52A) of the groove (52) is positioned closer to the outer surface (51) side of the glass film (50) than the outer surface (21) of the element body (20). In addition, the bottom (52A) of the groove (52) has an arc shape in the specific cross section.

Description

Electronic Components

[0001] The present disclosure relates to electronic components.

[0002] The invention described in Patent Document 1 comprises an element body, internal electrodes, a glass layer, and external electrodes. The internal electrodes are located inside the element body. The glass layer covers the surface of the element 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 of the glass layer with the element body. The external electrodes are laminated on the outer surface of the glass layer. The external electrodes are electrically connected to the internal electrodes.

[0003] Patent No. 6680075

[0004] In electronic components such as the invention described in Patent Document 1, the thicker the glass layer, the greater the stress in the glass layer. On the other hand, if the glass layer has through holes as described in Patent Document 1, the stress in the glass layer is released at the through holes. Therefore, in the electronic component, stress concentration at specific locations in the glass layer can be suppressed. However, in the electronic component described in Patent Document 1, the barrier properties of the glass layer are reduced because the glass layer has through holes. Therefore, there is a need for a structure that can reduce the stress in the glass layer while suppressing the reduction in the barrier properties of the glass layer.

[0005] In order to solve the above-described problems, one aspect of the present disclosure is an electronic component comprising an element body and a glass film covering an outer surface of the element body, wherein the glass film extends on the outer surface of the glass film and has a groove recessed from the outer surface of the glass film toward the outer surface of the element 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 closer to the outer surface of the glass film than the outer surface of the element body, and the bottom of the groove being arc-shaped in the specific cross section.

[0006] According to the above configuration, it is possible to suppress stress concentration in the glass film while ensuring the barrier properties of the glass film.

[0007] FIG. 1 is a perspective view of an electronic component. FIG. 2 is a side view of the electronic component. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. FIG. 4 is an enlarged view of the outer surface of the glass film of the electronic component. FIG. 5 is an enlarged view of the vicinity of the glass film when the electronic component is viewed in a specific cross section. FIG. 6 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 7 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 8 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 9 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 10 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 11 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 12 is an explanatory diagram illustrating a method for manufacturing an electronic component. FIG. 13 is an enlarged view of the vicinity of the glass film when the electronic component of a modified example is viewed in a specific cross section.

[0008] An embodiment of an electronic component will now be described with reference to the drawings. The drawings may show components enlarged for ease of understanding. The dimensional proportions of the components may differ from those in the actual components or from those in other drawings.

[0009] 1, the electronic component 10 is, for example, a surface-mount type negative temperature coefficient thermistor component mounted on a circuit board, etc. Note that a negative temperature coefficient thermistor component has the characteristic that its resistance value decreases as the temperature increases.

[0010] The electronic component 10 includes an element body 20. The element body 20 is generally rectangular prism-shaped and has a central axis CA. In the following description, an axis extending along the central axis CA is referred to as a first axis X. One of the axes perpendicular to the first axis X is referred to as a second axis Y. An axis perpendicular to the first axis X and the second axis Y is referred to as a third axis Z. One of the directions along the first axis X is referred to as a first positive direction X1, and the direction along the first axis X that is opposite to the first positive direction X1 is referred to as a first negative direction X2. One of the directions along the second axis Y is referred to as a second positive direction Y1, and the direction along the second axis Y that is opposite to the second positive direction Y1 is referred to as a second negative direction Y2. One of the directions along the third axis Z is referred to as a third positive direction Z1, and the direction along the third axis Z that is opposite to the third positive direction Z1 is referred to as a third negative direction Z2.

[0011] The outer surface 21 of the element body 20 has six flat surfaces. The term "surface" of the element body 20 used here refers to a surface that can be observed when the entire element body 20 is observed. In other words, even if there are minute irregularities or steps that are not visible unless a portion of the element body 20 is magnified and observed using a microscope, the surface is still referred to as a flat or curved surface. The six flat surfaces face in different directions. The six flat surfaces are broadly divided into a first end surface 22A facing the first positive direction X1, a second end surface 22B facing the first negative direction X2, and four side surfaces 22C. The four side surfaces 22C are, respectively, a surface facing the third positive direction Z1, a surface facing the third negative direction Z2, a surface facing the second positive direction Y1, and a surface facing the second negative direction Y2.

[0012] The boundary portions between two adjacent flat surfaces and the boundary portions between three adjacent flat surfaces on the outer surface 21 of the element body 20 are curved. That is, the corners of the element body 20 are rounded and chamfered. In Figures 1 and 2, the surface of a glass film 50 (described later) is identified with the outer surface 21 of the element body 20 and is given a reference numeral.

[0013] As shown in Fig. 2, the element body 20 has a larger dimension along the first axis X than along the third axis Z. Also, as shown in Fig. 1, the element body 20 has a larger dimension along the first axis X than along the second axis Y. The material of the element body 20 is a ceramic obtained by firing a metal oxide containing one or more elements selected from Mn, Fe, Ni, Co, Ti, Ba, Al, and Zn.

[0014] 3 , 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 embedded inside the element body 20.

[0015] The first internal electrode 41 is made of a conductive material. For example, the first internal electrode 41 is made of palladium. The second internal electrode 42 is made of the same material as the first internal electrode 41.

[0016] 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, similar to the first internal electrode 41.

[0017] The dimension of the first internal electrode 41 in the direction along the first axis X is smaller than the dimension of the element body 20 in the direction along the first axis X. Also, as shown in Fig. 1 , the dimension of the first internal electrode 41 in the direction along the third axis Z is approximately two-thirds of the dimension of the element body 20 in the direction along the third axis Z. The dimensions of the second internal electrode 42 in each direction are the same as those of the first internal electrode 41.

[0018] 3, the first internal electrodes 41 and the second internal electrodes 42 are positioned alternately 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 this order from the side surface 22C facing the second positive direction Y1 to the second negative direction Y2. In this embodiment, the distances between the internal electrodes in the direction along the second axis Y are equal.

[0019] 1, the two first internal electrodes 41 and the two second internal electrodes 42 are both located at the center of the element body 20 in the direction along the third axis Z. On the other hand, as shown in Fig. 3, the first internal electrodes 41 are located closer to the first positive direction X1, and the second internal electrodes 42 are located closer to the first negative direction X2.

[0020] Specifically, the end of the first internal electrode 41 on the first positive direction X1 side coincides with the end of the element body 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 element body 20 and does not reach the end of the element body 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 element body 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 element body 20 and does not reach the end of the element body 20 on the first positive direction X1 side.

[0021] As shown in FIG. 3 , the electronic component 10 includes a glass film 50. The glass film 50 covers the outer surface 21 of the element body 20. In this embodiment, the glass film 50 covers the entire outer surface 21 of the element body 20. The main material of the glass film 50 is insulating glass. Therefore, the glass film 50 contains silicon dioxide. The glass film 50 also contains, as an additive, one or more elements selected from alkali metals and alkaline earth metals. Specifically, the glass film 50 contains potassium as an additive. Therefore, in an element mapping image in a cross-sectional image of the glass film 50, the glass film 50 may have an interface due to the presence of potassium.

[0022] 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 is laminated on the glass film 50 in a portion of the outer surface 21 of the element body 20, including the first end face 22A. Specifically, the first base electrode 61A is a five-sided electrode that covers the first end face 22A of the element body 20 and portions of the four side faces 22C facing the first positive direction X1. In this embodiment, the first base electrode 61A is made of silver and glass.

[0023] The first metal layer 61B externally covers the first base electrode 61A, and is therefore stacked on the first base electrode 61A. Although not shown, the first metal layer 61B has a two-layer structure consisting of a nickel layer and a tin layer in this order from the first base electrode 61A side.

[0024] The second external electrode 62 has a second base electrode 62A and a second metal layer 62B. The second base electrode 62A is laminated on the glass film 50 in a portion of the outer surface 21 of the element body 20, including the second end face 22B. Specifically, the second base electrode 62A is a five-sided electrode that covers the second end face 22B of the element body 20 and portions of the four side faces 22C facing the first negative direction X2. In this embodiment, the material of the second base electrode 62A is the same as the material of the first external electrode 61, which is a mixture of silver and glass.

[0025] The second metal layer 62B externally covers the second base electrode 62A, and is therefore laminated on the second base electrode 62A. Specifically, the second metal layer 62B has a two-layer structure of nickel plating and tin plating, similar to the first metal layer 61B.

[0026] The second external electrode 62 does not reach the first external electrode 61 on the side surface 22C, and is spaced apart from the first external electrode 61 in the direction along the first axis X. In addition, the first external electrode 61 and the second external electrode 62 are not stacked in the central portion of the side surface 22C of the element body 20 in the direction along the first axis X, and the glass film 50 is exposed. Note that in Figures 1 to 3, the first external electrode 61 and the second external electrode 62 are shown by two-dot chain lines.

[0027] 3 , the first external electrode 61 and the end of the first internal electrode 41 on the first positive direction X1 side are connected via a first extension portion 71 that penetrates the glass film 50. Note that, as will be described in detail later, the first extension portion 71 is formed during the manufacturing process of the electronic component 10 when palladium that constitutes the first internal electrode 41 extends toward the first external electrode 61.

[0028] The second external electrode 62 and the end of the second internal electrode 42 on the first negative direction X2 side are connected via a second extension 72 that penetrates the glass film 50. Like the first extension 71, the second extension 72 is formed by palladium constituting the second internal electrode 42 extending toward the second external electrode 62 during the manufacturing process of the electronic component 10. Note that while FIG. 3 illustrates the first internal electrode 41 and the first extension 71 as separate components with a boundary, in reality, there is no clear boundary between them. The same applies to the second extension 72. The first extension 71 and the second extension 72 are not shown in FIGS. 1 and 2 .

[0029] 4, the glass film 50 has a groove 52 extending 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, the width of the opening edge 52B of the groove 52 on the outer surface 51 of the glass film 50 is defined as the opening width WG. In this case, when the extension length of the opening is five times or more the opening width WG, it is defined as "a groove 52 extending on the outer surface 51 of the glass film 50."

[0030] 5 , a cross section in a direction perpendicular to the outer surface 51 of the glass film 50 is defined 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 of the element body 20. The bottom 52A of the groove 52 is located closer to the outer surface 51 of the glass film 50 than the outer surface 21 of the element body 20. In other words, the groove 52 does not penetrate the glass film 50.

[0031] The bottom 52A and opening edge 52B of the groove 52 are determined as follows. First, the surface of the glass film 50 is photographed with an electron microscope. Then, cross-section processing is performed on any specific cross-section including the observed groove 52. Element mapping is then performed on the specific cross-section to obtain a mapping image that identifies the boundary with the element body 20 and the surface of the glass film 50 opposite the element body 20. In the mapping image, the lowest point TB of the groove 52 that is closest to the outer surface 21 of the element body 20 is identified. Then, the portion of the region including the lowest point TB is the bottom 52A.

[0032] Furthermore, a mapping image of the glass film 50 is obtained at the specific cross section as described above. Then, in the mapping image, an imaginary line V is drawn that circumscribes both outer surfaces 51 of the glass film 50 on both sides of the groove 52. At this time, the imaginary line V may partially coincide with the outer surface 51 of the glass film 50. Then, of the points of contact between the imaginary line V and the outer surface 51 of the glass film 50, the end closest to the center of the groove 52 is defined as the opening edge 52B.

[0033] In the specific cross section, the maximum depth SG of the groove 52 is approximately 750 nm. The maximum depth SG is the greater of the distances from both opening edges 52B to the lowest point TB in a direction perpendicular to the above-mentioned imaginary line V. In this embodiment, the opening width WG is approximately 870 nm. The opening width WG is the distance from one opening edge 52B to the other opening edge 52B on the imaginary line V.

[0034] In the specific cross section, the bottom 52A of the groove 52 is arc-shaped. In other words, the region that includes the lowest point TB in the specific cross section and is arc-shaped is the bottom 52A. Note that the "arc" here refers to the overall arc-shaped region, ignoring minute irregularities of less than 1 nm that cannot be clearly identified by observation with an electron microscope, for example. In the specific cross section, the radius of curvature R1 of the bottom 52A of the groove 52 is 10 nm or more. In this embodiment, the radius of curvature R1 of the bottom 52A of the groove 52 is approximately 315 nm. As described above, the opening width WG of the groove 52 is approximately 870 nm. Therefore, the radius of curvature R1 of the bottom 52A is at least one-fourth of the opening width WG.

[0035] The radius of curvature R1 of the bottom portion 52A is defined as follows: First, a mapping image of the glass film 50 including the bottom portion 52A is obtained as described above. Then, in the mapping image, an arc that approximates the surface of the bottom portion 52A is identified. Then, an approximation circle 52C that includes this arc is identified. The radius of this approximation circle 52C is defined as the radius of curvature R1.

[0036] In the specific cross section, a portion of the inner wall 52D of the groove 52 is arc-shaped. Specifically, a tangent line that is tangent to the inner wall 52D of the groove 52 and is inclined at 45 degrees with respect to the imaginary line V is defined as a specific tangent line SL. The point of contact between the specific tangent line SL and the inner wall 52D of the groove 52 is defined as a specific junction point SP. In this case, a portion PP of the inner wall 52D of the groove 52 that includes the specific junction point SP is arc-shaped. The radius of curvature R2 of the portion PP is 10 nm or more. In this embodiment, the radius of curvature R2 of the portion PP that includes the specific junction point SP is approximately 40 nm to 60 nm. Note that the radius of curvature R2 of one portion PP is not shown in FIG. 5.

[0037] <Regarding Glass Film Thickness> As shown in Fig. 5 , the shortest distance from the outer surface 21 of the element body 20 to the outer surface 51 of the glass film 50 is defined as the thickness TG of the glass film 50. The average thickness TG of the glass film 50 at locations where no grooves 52 are present is 300 nm or more. Specifically, in this embodiment, the average thickness TG of the glass film 50 is approximately 850 nm. The average thickness TG of the glass film 50 at locations where no grooves 52 are present is calculated as follows.

[0038] First, a location on the outer surface 51 of the glass film 50 where no grooves 52 exist is identified. Next, a specific cross section of the glass film 50 at that location is photographed using an electron microscope. In the photographed image, a range of at least 5 μm in the direction along the outer surface 51 of the glass film 50 is set as the measurement range. Then, image processing is used to calculate the cross-sectional area of ​​the glass film 50 in that measurement range. The cross-sectional area of ​​the glass film 50 in that measurement range is then divided by the length of that measurement range in the direction along the outer surface 51 of the glass film 50 to calculate the average thickness TG of the glass film 50. In other words, the average thickness TG of the glass film 50 is the average value of the thickness TG in the measurement range.

[0039] Furthermore, in the specific cross section, the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the element body 20 is approximately 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 element body 20 to the average thickness TG of the glass film 50 is 10% or more. In this embodiment, this ratio is approximately 10.6%.

[0040] <Method for Manufacturing Electronic Component> Next, a method for manufacturing electronic component 10 will be described. As shown in Fig. 6, the method for manufacturing electronic component 10 includes a laminate preparation step S11, an R-chamfering step S12, a solvent introduction step S13, a catalyst introduction step S14, an element introduction step S15, a polymer introduction step S16, and a metal alkoxide introduction step S17. The method for manufacturing electronic component 10 also includes a film formation step S18, a drying step S19, an immersion step S20, a baking step S21, a conductor application step S22, a curing step S23, and a plating step S24.

[0041] First, in forming the element body 20, in the laminate preparation step S11, a laminate is prepared, which is the rectangular parallelepiped element body 20. That is, the laminate at this stage is in a state before R-chamfering. For example, first, a plurality of ceramic sheets that will become the element body 20 are prepared. The sheets are thin plates. A conductive paste that will become the first internal electrode 41 is laminated on the sheets. A ceramic sheet that will become the element body 20 is laminated on the laminating paste. A conductive paste that will become the second internal electrode 42 is laminated on the sheet. In this manner, the ceramic sheets and the conductive paste are laminated. Then, by cutting to a predetermined size, an unfired laminate is formed. Thereafter, the unfired laminate is fired at a high temperature to prepare the laminate.

[0042] Next, as shown in Fig. 6, an R-chamfering process S12 is performed. In the R-chamfering process S12, curved surfaces are formed at the boundary portions between two adjacent flat surfaces and at the boundary portions between three adjacent flat surfaces of the laminate prepared in the laminate preparation process S11. For example, the corners of the laminate are R-chamfered by barrel polishing, thereby forming curved surfaces at the boundary portions.

[0043] Next, as shown in Fig. 6, a solvent introduction step S13 is performed. As shown in Fig. 7, in the solvent introduction step S13, 2-propanol is introduced into a reaction vessel 81 as a solvent 82. Next, as shown in Fig. 6, a catalyst introduction step S14 is performed. As shown in Fig. 8, in the catalyst introduction step S14, first, stirring of the solvent 82 in the reaction vessel 81 is started. Then, ammonia water is introduced into the reaction vessel 81 as an aqueous solution 83 containing a catalyst. The catalyst in this embodiment is hydroxide ions, which function as a catalyst for promoting hydrolysis of a metal alkoxide 85, which will be described later.

[0044] Next, an element body introduction step S15 is performed as shown in Fig. 6. In the element body introduction step S15, as shown in Fig. 9, a plurality of element bodies 20 formed in advance in the R-chamfering step S12 as described above are introduced into a reaction vessel 81.

[0045] Next, a polymer introduction step S16 is performed as shown in Fig. 6. As shown in Fig. 10, in the polymer introduction step S16, polyvinylpyrrolidone is introduced as a polymer 84 into a reaction vessel 81. As a result, the polymer 84 introduced into the reaction vessel 81 is adsorbed onto the outer surface 21 of the element body 20.

[0046] Next, as shown in Fig. 6, a metal alkoxide introduction step S17 is performed. As shown in Fig. 11, in the metal alkoxide introduction step S17, liquid tetraethyl orthosilicate is introduced into the reaction vessel 81 as the metal alkoxide 85. Note that tetraethyl orthosilicate is also called tetraethoxysilane. In this embodiment, the amount of metal alkoxide 85 introduced in the metal alkoxide introduction step S17 is calculated based on the area of ​​the outer surface 21 of the element bodies 20 introduced in the element introduction step S15. Specifically, the amount of metal alkoxide 85 is calculated by multiplying the amount of metal alkoxide 85 per element body 20 required to form the glass film 50 covering the outer surface 21 of the element body 20 by the number of element bodies 20.

[0047] Next, as shown in FIG. 6 , a film-forming step S18 is performed. In the film-forming step S18, the stirring of the solvent 82, which was initiated in the solvent-adding step S13 described above, is continued for a predetermined time after the metal alkoxide 85 is added to the reaction vessel 81 in the metal alkoxide-adding step S17. As a result, the metal alkoxide 85 is hydrolyzed by hydroxide ions, which serve as a catalyst. When the metal alkoxide 85 is hydrolyzed, the hydrolyzed metal alkoxide 85 adheres to the surface of the element body 20. Then, the metal alkoxides 85 attached to the surface of the element body 20 undergo dehydration condensation with each other to form the glass film 50. In the film-forming step S18, a sol-like glass film 50 is formed by a liquid-phase reaction in the reaction vessel 81.

[0048] Next, as shown in Fig. 6, a drying step S19 is performed. In the drying step S19, after the film-forming step S18, the element body 20 is removed from the reaction vessel 81 and dried. This dries the sol-like glass film 50 to form a gel-like glass film 50. In the drying step S19, cracks are generated that penetrate the glass film 50. These cracks are a precursor to the formation of grooves 52, which will be described later. The generation of the cracks distributes stress in the glass film 50.

[0049] Next, as shown in Fig. 6, an immersion step S20 is performed. As shown in Fig. 12, in the immersion step S20, a solution 87 containing at least one element selected from alkali metals and alkaline earth metals as an additive is first placed in a reaction vessel 86 different from the reaction vessel 81 used up to the film-forming step S18. In this embodiment, the solution 87 is a solution containing a potassium oxide precursor. Then, the element body 20 having the gel-like glass film 50 is immersed in the solution 87. As a result, the solution 87 adheres to the surface of the glass film 50. This lowers the melting point of the glass film 50.

[0050] Next, as shown in FIG. 6 , a baking step S21 is performed. In the baking step S21, the element body 20 immersed in the solution 87 in the immersion step S20 is first removed from the reaction vessel 86. The removed element body 20 is then baked in an atmosphere at 800°C for 20 minutes. This causes the glass film 50 to dissolve. A portion of the dissolved glass film 50 penetrates into the cracks formed in the drying step S19. As a result, a bottom portion 52A of the glass film 50 is formed on the outer surface 21 of the element body 20 exposed inside the cracks in the glass film 50, thereby forming a groove 52. At this time, due to surface tension, the glass wets up at the location in contact with the wall surface of the crack. Therefore, the bottom portion 52A has an arc shape in a specific cross section. Furthermore, in the baking step S21, the solvent of the solution 87 adhering to the surface of the glass film 50 volatilizes. Meanwhile, the potassium oxide precursor contained in the solution 87 precipitates on the outer surface 51 of the glass film 50.

[0051] Next, a conductor application step S22 is performed. In the conductor application step S22, a conductor paste is applied to two locations on the surface of the glass film 50: a portion including a portion covering the first end face 22A of the element body 20, and a portion including a portion covering the second end face 22B of the element body 20. Specifically, the conductor paste is applied to a portion of the element body 20 on the first positive direction X1 side, including the entire first end face 22A, so as to cover the glass film 50. In addition, the conductor paste is applied to a portion of the element body 20 on the first negative direction X2 side, including the entire second end face 22B, so as to cover the glass film 50.

[0052] Next, a curing step S23 is performed. Specifically, in the curing step S23, the element body 20 to which the glass film 50 and conductive paste have been applied is heated. As a result, the precipitated potassium oxide precursor becomes potassium oxide. The potassium oxide diffuses into the glass film 50 that covers the outer surface 21 of the element body 20. Then, water and polymer 84 evaporate from the gel-like glass film 50, hardening the sol that covers a portion of the outer surface 21 of the element body 20. Furthermore, the conductive paste applied to the outer surface 21 of the element body 20 hardens. That is, the first base electrode 61A and the second base electrode 62A are fired.

[0053] In this embodiment, during heating in the curing step S23, the Kirkendall effect, which arises from the difference in diffusion rate between the first internal electrode 41 and the first base electrode 61A, attracts palladium contained in the first internal electrode 41 toward the first base electrode 61A containing silver. As a result, the first extension portion 71 extends from the first internal electrode 41 toward the first base electrode 61A, penetrating the glass film 50, thereby connecting the first internal electrode 41 and the first base electrode 61A. The same applies to the second extension portion 72 connecting the second internal electrode 42 and the second base electrode 62A.

[0054] Next, a plating step S24 is performed. Electroplating is performed on the first base electrode 61A and the second base electrode 62A. As a result, a first metal layer 61B is formed on the surface of the first base electrode 61A. Furthermore, a second metal layer 62B is formed on the surface of the second base electrode 62A. Although not shown, the first metal layer 61B and the second metal layer 62B are electroplated with two types of metal, nickel and tin, to form a two-layer structure. In this manner, the electronic component 10 is formed.

[0055] <About the Barrier Property Test> A barrier property test was conducted on element bodies 20 covered with glass films 50 having grooves 52. For this test, five groups of samples were prepared, each with a plurality of samples. That is, a plurality of samples were prepared for each of Samples 1, 2, 3, 4, and 5. The glass films 50 were formed by performing the above-described element body insertion process S15 through baking process S21. Furthermore, by changing the conditions for each process for each of Samples 1 to 5, the thickness TG and other characteristics of the glass films 50 were varied for each sample group. Each sample was then left for 500 hours under conditions of a temperature of 85°C and a relative humidity of 90 to 95%. Thereafter, the resistance value of each sample was measured. Samples exhibiting deterioration in resistance value were classified as defective. In this test, a decrease in resistance value of 0.1% or more compared to the resistance value before exposure to the above temperature and relative humidity conditions was determined to have "deteriorated resistance value." This determination of whether or not the product was defective was carried out on a plurality of samples for each group, and the rate of defective products for each group was calculated.

[0056] In Sample 1, the average thickness TG of glass film 50 was 300 nm. The average radius of curvature R1 of bottom 52A of groove 52 in Sample 1 was 540 nm. The average radius of curvature R2 of portion PP of groove 52 in Sample 1 was 130 nm. The rate of defective products in Sample 1 was 0%.

[0057] In Sample 2, the average thickness TG of glass film 50 was 850 nm. The average radius of curvature R1 of bottom 52A of groove 52 in Sample 2 was 310 nm. The average radius of curvature R2 of portion PP of groove 52 in Sample 2 was 10 nm. The rate of defective products in Sample 2 was 0%.

[0058] In Sample 3, the average thickness TG of glass film 50 was 300 nm. The average radius of curvature R1 of bottom 52A of groove 52 in Sample 3 was 10 nm. The average radius of curvature R2 of portion PP of groove 52 in Sample 3 was 40 nm. The rate of defective products in Sample 3 was 0%.

[0059] In Sample 4, the average thickness TG of glass film 50 was 100 nm. The average radius of curvature R1 of bottom 52A of groove 52 in Sample 4 was 30 nm. The average radius of curvature R2 of portion PP of groove 52 in Sample 4 was 50 nm. The rate of defective products in Sample 4 was 0.3%.

[0060] In Sample 5, the average thickness TG of glass film 50 was 300 nm. The average radius of curvature R1 of bottom 52A of groove 52 in Sample 5 was 3 nm. The average radius of curvature R2 of portion PP of groove 52 in Sample 5 was 8 nm. The rate of defective products in Sample 5 was 0.2%.

[0061] 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 was found that the barrier properties were deteriorated compared to samples 1 to 3. In addition, in the case of sample 5, which produced defective products, the average value of the radius of curvature R1 of the bottom 52A of the groove 52 was smaller than that of the other samples. In this case, it was also found that the barrier properties were deteriorated compared to samples 1 to 3. In addition, in sample 5, the average value of the radius of curvature R2 of the portion PP of the groove 52 was smaller than that of the other samples. In this case, it was also found that the barrier properties were deteriorated compared to samples 1 to 3.

[0062] From the above test, it can be said that the average thickness TG of the glass film 50 is preferably 300 nm or more, and that the radius of curvature R1 of the bottom 52A of the groove 52 is preferably 10 nm or more. Furthermore, when the radius of curvature R2 of the portion PP of the groove 52 is large, it can be said that other objects are less likely to get caught near the opening edge 52B of the groove 52. In order to prevent such catching and ensure the characteristics of the product, it can be said that the radius of curvature R2 of the portion PP of the groove 52 is preferably 10 nm or more.

[0063] Advantages of the Present Embodiment (1) According to the above embodiment, the presence of the grooves 52 in the element body 20 releases stress in the glass film 50 at the grooves 52. This prevents stress from concentrating at specific locations on the glass film 50. Furthermore, the grooves 52 do not penetrate the glass film 50. That is, the outer surface 21 of the element body 20 is not exposed inside the grooves 52. Therefore, the above configuration ensures the barrier properties of the glass film 50. Furthermore, the bottoms 52A of the grooves 52 are arc-shaped. This prevents the grooves 52 from extending toward the outer surface 21 of the element body 20. This prevents the grooves 52 from unintentionally reaching the element body 20 and impairing the barrier properties of the glass film 50.

[0064] (2) In the above embodiment, the radius of curvature R1 of the bottom 52A of the groove 52 in the specific cross section is 10 nm or more. This arc size ensures a certain degree of curvature of the bottom 52A of the groove 52. Therefore, the effect described in (1) can be sufficiently obtained.

[0065] (3) In the above embodiment, in the specific cross section, the radius of curvature R1 of the bottom 52A of the groove 52 is equal to or greater than one-fourth 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 a sufficiently gentle arc, similar to the arc shape of the bottom 52A when the groove 52 is assumed to be semicircular. If the arc of the bottom 52A is gentle in this way, the groove 52 can be effectively prevented from expanding from the bottom 52A, even if an external force acts on the glass film 50, for example.

[0066] (4) In the above embodiment, the portion PP of the inner wall 52D of the groove 52, which includes the specific contact SP, is arc-shaped. The radius of curvature R2 of the portion PP is 10 nm or greater. The specific contact SP of the inner wall 52D is a location where the slope of the groove 52 becomes steeper, at 45 degrees or greater. Therefore, the location corresponding to the specific contact SP is likely to become caught when another object rubs against the electronic component 10. In this regard, as described above, because the portion PP including the specific contact SP is rounded, another object is less likely to become caught at the portion of the groove 52 corresponding to the specific contact SP. By suppressing such catching, the scratch resistance of the glass film 50 is improved.

[0067] (5) In the above embodiment, the average thickness TG of the glass film 50 is 300 nm or more at the locations where the grooves 52 are not present. This configuration ensures sufficient barrier properties of the glass film 50.

[0068] (6) In the above embodiment, in the specific cross-sectional view, the ratio of the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the element body 20 to the average thickness TG of the glass film 50 is 10% or more. With this configuration, even at the location where the glass film 50 is thinnest, a suitable thickness of the glass film 50 is ensured. In other words, the barrier properties of the glass film 50 are ensured.

[0069] <Modifications> The above embodiment and the following modifications can be implemented in combination with each other within the scope of technical compatibility.

[0070] The electronic component 10 is not limited to a negative temperature coefficient thermistor component. For example, it may be a multilayer capacitor component or an inductor component. The material of the element body 20 is not limited to the example in the above embodiment. The material of the element body 20 may be a composite of resin and metal powder.

[0071] The shape of the element body 20 is not limited to the example in the above embodiment. For example, the element body 20 may be a polygonal columnar shape other than a quadrangular columnar shape having a central axis CA. The element body 20 may also be the core of a wire-wound inductor component. For example, the core may have 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.

[0072] The boundary portion between adjacent flat surfaces on the outer surface 21 of the element body 20 does not have to be chamfered. In this case, there is no curved surface at the boundary portion. The shapes of the first internal electrodes 41 and second internal electrodes 42 are not important as long as they ensure electrical conduction with the corresponding first external electrodes 61 and second external electrodes 62. Furthermore, the number of first internal electrodes 41 and second internal electrodes 42 is not important, and the number of internal electrodes may be one, or three or more.

[0073] The configuration 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, or the first metal layer 61B may not have a two-layer structure. The same applies to the second external electrode 62.

[0074] The material combination of the first internal electrode 41 and the first base electrode 61A is not limited to palladium and silver. For example, it may be copper and nickel, copper and silver, silver and gold, nickel and cobalt, or nickel and gold. It may also be silver on one side and silver and palladium on the other side. It may also be palladium on one side and silver and palladium on the other side, or copper on one side and silver and palladium on the other side. It may also be gold on one side and silver and palladium on the other side.

[0075] Depending on the combination of the first internal electrode 41 and the first base electrode 61A, the Kirkendall effect may not be achieved. In this case, the first internal electrode 41 may be processed so as to be exposed from the glass film 50 before the conductor application step S22. For example, the glass film 50 on the first end face 22A side of the element body 20 may be polished to physically remove a portion of the glass film 50. The conductor application step S22 may then be performed to connect the first internal electrode 41 and the first base electrode 61A. Alternatively, for example, after forming the first base electrode 61A, the glass film 50 may be formed on the surface of the first base electrode 61A as well, and the glass film 50 covering the surface of the first base electrode 61A may then be removed. This also applies to the combination of materials for the second internal electrode 42 and the second base electrode 62A.

[0076] The location of the first external electrode 61 is not limited to the example in the above embodiment. For example, the first external electrode 61 may be disposed only on the first end surface 22A and one side surface 22C. The same applies to the second external electrode 62.

[0077] In the specific cross section of the above embodiment, the radius of curvature R1 of the bottom 52A of the groove 52 may be less than 10 nm. As long as at least the bottom 52A is arc-shaped, the effect described in (1) can be expected.

[0078] In the specific cross section of the above embodiment, the radius of curvature R2 of the portion PP including the specific contact point SP of the inner wall 52D of the groove 52 may be less than 10 nm. Furthermore, the portion PP does not have to be arc-shaped.

[0079] In the above embodiment, a portion of the glass film 50, including the opening edge 52B, may be arc-shaped. In the example shown in FIG. 13 , the glass film 50 has a groove 52 extending on the outer surface 51 of the glass film 50. A cross section perpendicular to the outer surface 51 of the glass film 50 is defined 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 of the element body 20. The bottom 52A of the groove 52 is located closer to the outer surface 51 of the glass film 50 than the outer surface 21 of the element body 20. In other words, the groove 52 does not penetrate the glass film 50. In the specific cross section, the bottom 52A of the groove 52 is arc-shaped. In the example shown in FIG. 13 , the radius of curvature R1 of the bottom 52A of the groove 52 is approximately 1 μm.

[0080] 13, in the specific cross section, a portion PQ including the opening edge 52B of the groove 52 has an arc shape. Specifically, the portion PQ has an arc shape that is convex toward the opposite side from the element body 20. The radius of curvature of the portion PQ is 10 nm or more. In the example shown in FIG. 13, the radius of curvature of the arc of the portion PQ is approximately 10 to 30 nm.

[0081] 13 , the opening width WG of the opening edge 52B of the groove 52 in the specific cross section is approximately 1.2 μm. That is, the curvature radius R1 of the bottom 52A of the groove 52 in the specific cross section is equal to or greater than one-fourth the opening width WG of the opening edge 52B of the groove 52.

[0082] 13 , a first imaginary line V1 is drawn connecting the opening edges 52B on both sides of the groove 52 in a specific cross section. The position where the maximum depth SG of the groove 52 is halfway is defined as the midpoint MP, and a second imaginary line V2 is drawn through the midpoint MP and parallel to the first imaginary line V1. In the specific cross section, it is preferable that twice the radius of curvature R1 of the bottom 52A of the groove 52 be equal to or greater than the length of the second imaginary line V2 bounded by the inner wall 52D of the groove 52. With this configuration, 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, stress is sufficiently dispersed at the bottom 52A of the groove 52 and the bottom 52A of the glass film 50. Although not shown in the figures, in the above embodiment, the value obtained by doubling the radius of curvature R1 of the bottom 52A of the groove 52 is equal to or greater than the length of the second virtual line V2 bounded by the inner wall 52D of the groove 52 in a specific cross section.

[0083] In the above embodiment, the average thickness TG of glass film 50 at locations where grooves 52 are not present may be less than 300 nm. Furthermore, in a specific cross section, the ratio of the shortest distance SD from bottom 52A of groove 52 to outer surface 21 of element body 20 to the average thickness TG of glass film 50 may be less than 10%. That is, it is sufficient that bottom 52A of groove 52 is located closer to outer surface 51 of glass film 50 than outer surface 21 of element body 20.

[0084] The configuration of the glass film 50 is not limited to the example of the above embodiment. For example, it does not have to cover the entire area of ​​the outer surface 21 of the element body 20. The area covered by the glass film 50 may be changed as appropriate depending on the shape of the element body 20, the positions of the first external electrode 61 and the second external electrode 62, etc.

[0085] The glass film 50 and the first base electrode 61A may be integrated with each other by the glass contained in the glass film 50 diffusing into the first base electrode 61A. This also applies to the glass film 50 and the second base electrode 62A.

[0086] The glass film 50 does not necessarily contain one or more elements selected from alkali metals and alkaline earth metals as additives. The material of the glass film 50 is not limited to the example of the above embodiment. For example, the glass is not limited to silicon dioxide, but may be a multi-component oxide containing Si, such as B-Si, Si-Zn, Zr-Si, or Al-Si oxides. The glass may also be a multi-component oxide containing an alkali metal and Si, such as Al-Si, Na-Si, or Li-Si oxides. Furthermore, the glass may also be a multi-component oxide containing an alkaline earth metal and Si, such as Mg-Si, Ca-Si, Ba-Si, or Sr-Si oxides. The glass may not necessarily contain Si, and may be a mixture of these.

[0087] The material of the glass film 50 may contain, in addition to glass, a pigment, a silicone-based flame retardant, a surface treatment agent such as a silane coupling agent or a titanate coupling agent, or an antistatic agent.

[0088] More specifically, the glass film 50 may contain, in addition to glass, additives such as fine particles and nanoparticles of organic acid salts, oxides, inorganic salts, organic salts, and other metal oxides. The additives contained in the solution 87 are not limited to potassium oxide precursors.

[0089] Examples of organic acid salts include salts of oxoacids such as soda ash, sodium carbonate, sodium hydrogencarbonate, sodium percarbonate, sodium sulfite, sodium hydrogensulfite, sodium sulfate, sodium thiosulfate, sodium nitrate, and sodium sulfite; and halogen compounds such as sodium fluoride, sodium chloride, sodium bromide, and sodium iodide.

[0090] Examples of oxides include sodium peroxide, examples of hydroxides include sodium hydroxide, and examples of inorganic salts include sodium hydride, sodium sulfide, sodium hydrogen sulfide, sodium silicate, trisodium phosphate, sodium borate, sodium borohydride, sodium cyanide, sodium cyanate, and sodium tetrachloroaurate.

[0091] Examples of inorganic salts include calcium peroxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium hydride, calcium carbide, and calcium phosphide.

[0092] The additive may be an oxoacid salt such as calcium carbonate, calcium bicarbonate, 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, or hydroxyapatite. Further examples of the additive include calcium acetate, calcium gluconate, calcium citrate, calcium malate, calcium lactate, calcium benzoate, calcium stearate, and calcium aspartate.

[0093] Furthermore, for example, the additive may 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 tetramethylpiperidide, lithium sulfide, lithium sulfate, lithium thiophenolate, or lithium phenoxide.

[0094] Also for example, the additive may be boron triiodide, sodium cyanoborohydride, sodium borohydride, tetrafluoroboric acid, triethylborane, borax, or boric acid.

[0095] For example, 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, or sodium acetate or sodium citrate.

[0096] The additive may also be fine particles or nanoparticles of a metal oxide, such as sodium oxide, calcium oxide, lithium oxide, boron oxide, barium oxide, silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, zinc oxide, and magnesium oxide.

[0097] In the above embodiment, examples of the potassium oxide precursor include potassium arsenide, potassium bromide, potassium carbonate, potassium chloride, potassium fluoride, potassium hydride, potassium iodide, potassium triiodide, potassium azide, potassium nitride, potassium superoxide, potassium ozonate, potassium peroxide, potassium phosphide, potassium sulfide, potassium selenide, potassium telluride, potassium tetrafluoroaluminate, potassium tetrafluoroborate, potassium tetrahydroborate, potassium methanide, potassium cyanide, potassium formate, and potassium hydrogen fluoride. Sodium, tetraiodomercury(II), potassium hydrogen sulfide, potassium octachlorodimolybdate(II), potassium amide, potassium hydroxide, potassium hexafluorophosphate, potassium carbonate, potassium tetrachloroplatinate(II), potassium hexachloroplatinate(IV), potassium nonahydrido rhenate(VII), potassium sulfate, potassium acetate, potassium cyanideaurate(I), potassium hexanitrocobaltate(III), potassium hexacyanoferrate(III), potassium hexacyanoferrate(II), potassium methoxide oxide, 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 tetrakis(peroxo)chromate(V), potassium cuprate(III), potassium ferrate, potassium iodate, potassium periodate, potassium permanganate, potassium manganate, Examples include potassium hypomanganate, potassium molybdate, potassium nitrite, potassium nitrate, tripotassium phosphate, potassium perrhenate, potassium selenate, potassium silicate, potassium sulfite, potassium sulfate, potassium thiosulfate, potassium disulfite, potassium dithionate, potassium disulfate, potassium peroxodisulfate, potassium dihydrogen arsenate, dipotassium hydrogen arsenate, potassium bicarbonate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium hydrogen selenate, potassium hydrogen sulfite, potassium hydrogen sulfate, and potassium hydrogen peroxosulfate.

[0098] Examples of the metal alkoxide 85 include sodium methoxide, sodium ethoxide, calcium diethoxide, lithium isopropoxide, lithium ethoxide, lithium tert-butoxide, lithium methoxide, boron alkoxide, potassium t-butoxide, tetraethyl orthosilicate, allyltrimethoxysilane, isobutyl(trimethoxy)silane, tetrapropyl orthosilicate, tetramethyl orthosilicate, [3-(diethylamino)propyl]trimethoxysilane, triethoxy( octyl)silane, triethoxyvinylsilane, triethoxyphenylsilane, trimethoxyphenylsilane, trimethoxymethylsilane, butyltrichlorosilane, n-propyltriethoxysilane, methyltrichlorosilane, dimethoxy(methyl)octylsilane, dimethoxydimethylsilane, tris(tert-butoxy)silanol, tris(tert-pentoxy)silanol, hexadecyltrimethoxysilane, tris(1,2-benzenediolate-O,O')dipotassium silicate, ol Tetrabutyl tosilicate, aluminum silicate, calcium silicate, tetramethylammonium silicate solution, chlorotriisopropoxytitanium(IV), titanium(IV) isopropoxide, titanium(IV) 2-ethylhexyl oxide, titanium(IV) ethoxide, titanium(IV) butoxide, titanium(IV) tert-butoxide, titanium(IV) propoxide, titanium(IV) methoxide, zirconium(IV) bis(diethylcitrate)dipropoxide, zirconium(IV) dibutoxide ( bis-2,4-pentanedionate), 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, aluminum phenoxide.

[0099] In the above embodiment, the manufacturing method of the electronic component 10 may be different from that of the above embodiment. For example, the glass film 50 may be formed by the following method. First, a thin film that serves as the base of the glass film 50 is formed on the outer surface 21 of the chamfered element body 20 by a barrel spray method or the like. Then, an additive containing at least one element selected from alkali metals and alkaline earth metals is added to the thin film to form the glass film 50.

[0100] The solvent 82 introduced in the solvent introduction step S13 is not limited to the example of the above embodiment, and may be any liquid capable of adequately dispersing the metal alkoxide 85. The solvent introduction step S13 may be performed after the catalyst introduction step S14 or the matrix introduction step S15. The solvent introduction step S13 may be performed prior to at least one of the metal alkoxide introduction step S17 and the catalyst introduction step S14. The solvent introduction step S13 may also be omitted. In this case, for example, if the amount of water contained in the catalyst-containing aqueous solution 83 is adequately large, the metal alkoxide 85 will react in the liquid phase. The catalyst-containing aqueous solution 83 may also be introduced in a state where it is mixed with an organic solvent as the solvent 82.

[0101] Although the catalyst-containing aqueous solution 83 is ammonia water and the catalyst is hydroxide ions, the catalyst is not limited to this. A basic aqueous solution can catalyze the hydrolysis of the metal alkoxide 85, similar to 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 it contains ions that can catalyze hydrolysis.

[0102] Although the catalyst has been described as being introduced as an aqueous solution 83 containing the catalyst, a solid compound containing the catalyst and water may be introduced separately into the reaction vessel 81. In this case, the catalyst can be considered to have been introduced into the reaction vessel 81 when it is produced in the reaction vessel 81. Alternatively, for example, a solid compound containing the catalyst may be introduced into the reaction vessel 81, and moisture in the air may be used as the water required for hydrolysis.

[0103] The raw material introduction step S15 may be performed before the catalyst introduction step S14. Furthermore, when the raw material introduction step S15 is performed before the catalyst introduction step S14, the metal alkoxide introduction step S17 may be performed before the catalyst introduction step S14 or the raw material introduction step S15. The raw material introduction step S15 may be performed before at least one of the metal alkoxide introduction step S17 and the catalyst introduction step S14.

[0104] In the manufacturing method of electronic component 10 according to the above embodiment, a solution containing a precursor for generating metal alkoxide 85 may be added instead of metal alkoxide 85. In this case, in metal alkoxide addition step S17, a metal complex or acetate, which is a metal alkoxide precursor, may be added. Examples of metal complexes include acetylacetonates such as lithium acetylacetonate, titanium(IV) oxyacetylacetonate, titanium diisopropoxide bis(acetylacetonate), zirconium(IV) trifluoroacetylacetonate, zirconium(IV) acetylacetonate, aluminum acetylacetonate, aluminum(III) acetylacetonate, calcium(II) acetylacetonate, and zinc(II) acetylacetonate. Examples of acetates include zirconium acetate, zirconium(IV) hydroxide acetate, and basic aluminum acetate.

[0105] In the metal alkoxide introduction step S17, the metal alkoxide 85 may be generated in the reaction vessel 81 instead of being introduced into the reaction vessel 81 after being generated outside the reaction vessel 81. For example, the metal alkoxide 85 may be generated by the reaction of a metal salt with an alcohol. Therefore, even when a metal salt and an alcohol, which are metal alkoxide precursors, are introduced into the reaction vessel 81 and the metal alkoxide 85 is generated by the reaction between them, it can be considered that the metal alkoxide 85 has been introduced into the reaction vessel 81.

[0106] 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, or the like. When the metal contained in the metal alkoxide 85 is silicon, the reaction rate is slower than with other metals, making it easier to control the reaction rate of the metal alkoxide 85 to a constant value. The alkoxy group of the metal alkoxide 85 may be a methoxy group, a propoxy group, or the like, or may be modified with a functional group such as a long-chain alkyl group or an epoxy group, as in a coupling agent. Furthermore, the coordination number of the metal contained in the metal alkoxide 85 is not limited to four, but may be three or two.

[0107] The reaction vessel 81 used in the immersion step S20 and the reaction vessel 86 used in the film-forming step S18 do not need to be different. In the immersion step S20, it is sufficient that the solution 87 adheres to the glass film 50 covering the outer surface 21 of the element body 20, and the entire element body 20 does not need to be immersed in the solution 87 in the reaction vessel 86. For example, the solution 87 may be applied only to the portion of the outer surface 21 of the element body 20 that is covered with the glass film 50. Furthermore, the method of adding the alkali metal and alkaline earth metal to the gel-like glass film 50 is not limited to the immersion method, and they may also be added by spraying or the like.

[0108] The curing step S23 is not limited to a step of simultaneously curing the glass film 50 and the conductive paste. For example, if the conductive paste is a material that is cured by ultraviolet light irradiation, a heating step may be performed as a step of curing the glass film 50, and ultraviolet light may be irradiated as a step of curing the conductive paste.

[0109] In the above embodiment, the process from the element body introduction step S15 to the drying step S19 may be performed once, and then the process from the element body introduction step S15 to the drying step S19 may be performed again repeatedly. By repeatedly performing these processes, the thickness TG of the glass film 50 increases.

[0110] In the above embodiment, the immersion step S20 and the baking step S21 may be performed once, and then the immersion step S20 and the baking step S21 may be performed repeatedly. By repeatedly performing these steps, the shortest distance SD from the bottom 52A of the groove 52 to the outer surface 21 of the element body 20 increases, and the radius of curvature R1 of the bottom 52A changes.

[0111] <Supplementary Notes> The technical concepts that can be derived from the above embodiments and modified examples are described below: [1] An electronic component comprising an element body and a glass film covering an outer surface of the element body, the glass film extending on the outer surface of the glass film and having a groove recessed from the outer surface of the glass film toward the outer surface of the element 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 closer to the outer surface of the glass film than the outer surface of the element body, and the bottom of the groove being arc-shaped in the specific cross section.

[0112] [2] The electronic component according to [1], wherein the radius of curvature of the bottom of the groove in the specific cross section is 10 nm or more. [3] The electronic component according to [1] or [2], wherein the radius of curvature of the bottom of the groove in the specific cross section is one-fourth or more of the width of the opening edge of the groove.

[0113] [4] An electronic component according to any one of [1] to [3], wherein, in the specific cross section, when a line connecting the opening edges on both sides of the groove is defined as a virtual line, a tangent line that is tangent to the inner wall of the groove and is inclined at 45 degrees to the virtual line is defined as a specific tangent, and a point of contact between the specific tangent and the inner wall of the groove is defined as a specific junction, a portion of the inner wall of the groove that includes the specific junction is arc-shaped in the specific cross section, and a radius of curvature of the portion is 10 nm or more.

[0114] [5] The electronic component according to any one of [1] to [4], wherein the average thickness of the glass film at locations where the grooves are not present is 300 nm or more. [6] The electronic component according to any one of [1] to [5], wherein the ratio of the shortest distance from the bottom of the groove to the outer surface of the element body to the average thickness of the glass film at the specific cross section is 10% or more.

[0115] DESCRIPTION OF SYMBOLS 10: Electronic component 20: Body 21: Outer surface 50: Glass film 51: Outer surface 52: Groove 52A: Bottom 52B: Opening edge

Claims

1. a glass film covering an outer surface of the element body; the glass film has a groove extending on an outer surface of the glass film and recessed from the outer surface of the glass film toward the outer surface of the element body in a specific cross section in a direction perpendicular to the outer surface of the glass film, a bottom of the groove is located closer to the outer surface of the glass film than the outer surface of the element body, The bottom of the groove is arc-shaped in the specific cross section. Electronic components.

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

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

4. In the specific cross section, a line connecting the opening edges on both sides of the groove is defined as a virtual line, a tangent line that contacts the inner wall of the groove and is inclined at 45 degrees with respect to the virtual line is defined as a specific tangent line; When the contact point between the specific tangent line and the inner wall of the groove is defined as the specific contact point, In the specific cross section, a portion of the inner wall of the groove including the specific contact point is arc-shaped, The radius of curvature of the portion is 10 nm or more. The electronic component according to claim 1 .

5. The average thickness of the glass film at the location where the grooves are not present is 300 nm or more. The electronic component according to claim 1 .

6. In the specific cross section, the ratio of the shortest distance from the bottom of the groove to the outer surface of the element body to the average thickness of the glass film is 10% or more. The electronic component according to claim 1 .