Electronic component

Abstract

This electronic component (10) comprises an element body (20) and a glass film (50) that covers the outer surface (21) of the element body (20). The glass film (50) includes a mesh forming oxide or a conditional glass forming oxide. An arbitrarily defined site inside the glass film (50) serves as a first region (A1). A site inside the glass film (50) that is located further toward the element body (20) relative to the first region (A1) serves as a second region (A2). The magnitude of the binding energy of a main skeleton component in the first region (A1) is less than the magnitude of the binding energy of a main skeleton component in the second region (A2).

Description

Electronic Components

[0001] The present disclosure relates to electronic components.

[0002] The electronic component described in Patent Document 1 includes an element body, an internal electrode, a base electrode, and a glass film. The element body is made of ceramic. The internal electrode is located inside the element body. The glass film covers the outer surface of the element body. The base electrode covers part of the surface of the glass film. The internal electrode penetrates the glass film and is connected to the base electrode.

[0003] Patent No. 5180753

[0004] In electronic components such as those described in Patent Document 1, physical impacts may be applied to the glass film when the electronic component collides with other components. In this case, the stronger the bonds between the main skeleton components of the glass film, the more difficult it is to disperse the impact. In other words, stress is concentrated at specific points in the glass film, making it more likely to crack.

[0005] In order to solve the above problems, the present disclosure provides an electronic component comprising an element body and a glass film covering an outer surface of the element body, wherein the glass film contains an oxide of one or more elements selected from boron, aluminum, silicon, phosphorus, titanium, vanadium, gallium, germanium, arsenic, zirconium, molybdenum, antimony, and tungsten, wherein the oxide contained in the glass film with the greatest content is a main skeleton component of the glass film, an arbitrary location inside the glass film is defined as a first region, and a location inside the glass film that is closer to the element body than the first region is defined as a second region, wherein the magnitude of the bond energy of the main skeleton component in the first region is smaller than the magnitude of the bond energy of the main skeleton component in the second region.

[0006] This can prevent cracks from occurring in the glass film.

[0007] FIG. 1 is a perspective view of an electronic component according to a first embodiment. FIG. 2 is a side view of the electronic component according to the first embodiment. FIG. 3 is a cross-sectional view taken along line 3-3 in FIG. 2. FIG. 4 is an enlarged cross-sectional view of a glass film. FIG. 5 is a schematic diagram of the distribution of bonding energy. FIG. 6 is a flowchart of a method for manufacturing an electronic component according to the first embodiment. FIG. 7 is a flowchart of a method for manufacturing an electronic component according to a second embodiment.

[0008] Hereinafter, first and second embodiments of the electronic component will be described with reference to the drawings. Note that the drawings may show components enlarged to facilitate understanding. The dimensional ratios of the components may differ from those in the actual drawings or from those in other drawings.

[0009] 1, an electronic component 10 is a surface-mount type negative temperature coefficient thermistor component that is mounted on, for example, 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 22. The term "surface" of the element body 20 as used herein 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 or the like, the surface is still referred to as a flat or curved surface. The six flat surfaces 22 face in different directions. The six flat surfaces 22 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] In the outer surface 21 of the element body 20, the boundary portions between two adjacent flat surfaces 22 and the boundary portions between three adjacent surfaces are curved. That is, the corners of the element body 20 are rounded and chamfered. In Figures 1 and 2, the outer surface 51 of a glass film 50 (described later) is identified with the outer surface 21 of the element body 20 and is given a reference number.

[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 approximately 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 electrodes 41, the second internal electrodes 42, the first internal electrodes 41, and the second internal electrodes 42 are arranged in this 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.

[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 substantially the entire area of ​​the outer surface 21 of the element body 20. The main material of the glass film 50 is insulating glass. Details of the components contained in the glass film 50 will be described later.

[0022] The electronic component 10 includes a first external electrode 61 and a second external electrode 62. In FIGS. 1 to 3 , the first external electrode 61 and the second external electrode 62 are indicated by dashed double-dashed lines. As shown in FIG. 3 , 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 and portions of the four side faces 22C of the element body 20 facing in the first positive direction X1. In this embodiment, the material of the first base electrode 61A is a mixture 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, i.e., the second metal layer 62B is laminated on the second base electrode 62A. Similar to the first metal layer 61B, the second metal layer 62B has a two-layer structure of nickel plating and tin plating in this order from the element body 20 side.

[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.

[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 through portion 71 that penetrates the glass film 50. Note that, as will be described in detail later, the first through portion 71 is formed during the manufacturing process of the electronic component 10 when palladium constituting 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 through portion 72 that penetrates the glass film 50. Similar to the first through portion 71, the second through portion 72 is formed by the palladium constituting the first internal electrode 41 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 through portion 71 as separate components with a boundary, in reality, there is no clear boundary between them. The same applies to the second through portion 72. The first through portion 71 and the second through portion 72 are not shown in FIGS. 1 and 2 .

[0029] (Composition of the Glass Film) The glass film 50 contains an oxide of one or more elements selected from boron (B), aluminum (Al), silicon (Si), phosphorus (P), titanium (Ti), vanadium (V), gallium (Ga), germanium (Ge), arsenic (As), zirconium (Zr), molybdenum (Mo), antimony (Sb), and tungsten (W). Hereinafter, the oxide with the highest content among the oxides contained in the glass film 50 is referred to as the main skeleton component of the glass film 50. The main skeleton component forms an alpha-mos structure, or a so-called mesh structure, of the glass film 50. This mesh structure is sometimes referred to as a glass network. Hereinafter, a weak bond between the main skeleton components in the mesh structure may be referred to as a "loose glass network."

[0030] More specifically, the oxides of the above elements are network-forming oxides or conditional glass-forming oxides. Network-forming oxides are oxides that can form a network structure by themselves. For example, network-forming oxides include B ２ O ３ (3) B ２ O ３ (4) Al ２ O ３ (4) SiO ２ (4) P ３ O ５ (4) V ２ O ５ (4) GeO ２ (4) As ２ O ５ (4) ZrO ２ (6), and Sb ２ O ５ (4), etc. The values ​​in parentheses are the coordination numbers of other elements to oxygen atoms. A conditional glass-forming oxide is an oxide that can form a network structure in combination with other substances. For example, a conditional glass-forming oxide is Al ２ O ３ (CaO), TiO ２ (K ２ O or Cs ２ O), V ２ O ５ (BaO or PbO), Ga２ O ３ (CaO), MoO ３ (K ２ O), WO ３ (K ２ O), etc. The composition formulas shown in parentheses are composition formulas of compounds necessary for the conditional glass-forming oxides to form a network structure. Therefore, the glass film 50 has a network structure in which the network-forming oxides or the conditional glass-forming oxides are the main skeleton component. In this embodiment, the main skeleton component of the glass film 50 is SiO ２ That is, the main skeleton component of the glass film 50 is an oxide of silicon.

[0031] The main skeleton component is identified by energy dispersive X-ray spectroscopy (EDX) of a cross section of the glass film 50. Specifically, first, the element body 20 is ground in a direction perpendicular to the outer surface 21 by focused ion beam processing or the like. Next, an electron beam is irradiated onto the ground cross section of the element body 20 using a transmission electron microscope (TEM). The range to be irradiated with the electron beam is a range of 500 nm or more in a direction along the outer surface 51 of the glass film 50. The amount of characteristic X-rays generated at this time is measured to identify the composition of the element body 20 on the ground cross section. Then, of the identified compositions, the oxide that is the above-mentioned oxide and that has the highest content is identified as the main skeleton component of the glass film 50.

[0032] In addition to the main skeleton components, the glass film 50 also contains one or more elements selected from alkali metals and alkaline earth metals as additives. In this embodiment, the glass film 50 contains potassium as an additive. The value of "K / Si," which is the ratio of potassium to silicon contained in the glass film 50, is 0.5 atm% or more and 90 atm% or less. Specifically, the ratio of potassium to silicon contained in the glass film 50 is approximately 30 atm%.

[0033] As shown in Figure 4, the dimension of the glass film 50 in a direction perpendicular to the outer surface 21 of the element body 20 is defined as the thickness TG of the glass film 50. In the range of 1% to 90% of the thickness TG from the outer surface 51 of the glass film 50, the average content of the additive is 3% or more, preferably 10% or more. In particular, in this embodiment, in the range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50, the average content of the additive is 20% to 40%. Furthermore, in the range closer to the element body 20 than the range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50, the average content of the additive is less than 20%.

[0034] Here, any location within a range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50 is defined as a first region A1. Any location within a range closer to the element body 20 than the above range is defined as a second region A2. In this case, the average content ratio of the additive in the first region A1 is greater than the average content ratio of the additive in the second region A2.

[0035] The content ratio of the additive refers to the percentage of the additive relative to the total composition contained in the element body 20. The average content ratio of the additive is calculated using EDX. Specifically, first, the ground cross section of the element body 20 is observed using the method described above. Next, mapping data of the additives on the ground cross section is obtained using EDX. The mapping data is in the form of an image. In the mapping data, the higher the dose of characteristic X-rays, the higher the brightness value in the image. In other words, in the mapping data, the higher the amount of additive, the higher the brightness value in the image. The average content ratio of the additive is calculated by dividing the sum of the brightness values ​​present in a specific region of this mapping data by the area of ​​the region. In this embodiment, the specific region is a range of several nm in a direction perpendicular to the outer surface 51 of the glass film 50 and 500 nm or more in a direction along the outer surface 51 of the glass film 50.

[0036] Here, the additive breaks some of the bonds of the main skeleton component inside the glass film 50. In this embodiment, potassium, which is an additive, breaks the siloxane bonds of silicon dioxide, which is the main skeleton component. The potassium then bonds to oxygen atoms that make up the network structure. In other words, the potassium additive replaces oxygen atoms in silicon dioxide, which is the main skeleton component. As a result, siloxane bonds are no longer formed at the locations where potassium has replaced them. As a result, reflecting the additive content inside the glass film 50, the bond energy of the main skeleton component in the range of 5% to 20% of the thickness T from the outer surface 51 of the glass film 50 is smaller than the bond energy of the main skeleton component in the range closer to the element 20 than that range. In other words, the glass network in the range of 5% to 20% of the thickness T from the outer surface 51 of the glass film 50 is looser than the glass network in the range closer to the element 20 than that range. Details of the "bond energy of the main skeleton component" will be described later.

[0037] 4, the element body 20 is ground in a direction perpendicular to the outer surface 21 by focused ion beam processing or the like. Then, the glass film 50 is viewed in a cross section perpendicular to the outer surface 21 of the element body 20. Next, in the cross section of the glass film 50, a boundary line B is drawn in a direction perpendicular to the outer surface 51 of the glass film 50 at any point between a point 10 nm away from the outer surface 51 of the glass film 50 and a point 10 nm away from the outer surface 21 of the element body 20. The boundary line B extends along the outer surface 51 of the glass film 50. The difference between the average value of the additive content within a 10 nm range from the boundary line B toward the outer surface 51 of the glass film 50 in a direction perpendicular to the boundary line B and the average value of the additive content within a 10 nm range from the boundary line B toward the element body 20 in a direction perpendicular to the boundary line B is less than 40%. This relationship between the difference in content is satisfied regardless of where the boundary line B is drawn within the range. That is, the content of the additive inside the glass film 50 increases continuously from the element body 20 side toward the outer surface 51 of the glass film 50 .

[0038] Therefore, reflecting the distribution of the content ratio of such additives, the bond energy of the main skeleton component in the first region A1 is smaller than the bond energy of the main skeleton component in the second region A2. In other words, the glass network in the first region A1 is looser than the glass network in the second region A2.

[0039] (Regarding the bond energy of the main skeleton component) The "bond energy of the main skeleton component" will be described below using an example of a calculation method for the first region A1 and the second region A2. In this embodiment, the "bond energy of the main skeleton component" is a representative value of the bond energy in each region calculated using X-ray photoelectron spectroscopy (XPS).

[0040] First, the outer surface 51 of the glass film 50 is ground in a direction parallel to the outer surface 51 by sputtering or the like. Next, X-rays are irradiated at any location on the ground surface, which is the outer surface 51 of the ground glass film 50. The X-rays are soft X-rays such as Al-Kα rays. Therefore, the first region A1 is a region several nanometers deep from the X-ray irradiated location on the ground surface. Note that the first region A1 is located within a range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50 before grinding. When X-rays are irradiated, photoelectrons are emitted from the main skeleton component present in the first region A1. Then, the distribution of the bond energy of the main skeleton component is calculated from the distribution of the kinetic energy of the photoelectrons. In this embodiment, the main skeleton component is SiO ２ Therefore, the binding energy distribution of the 2p orbital of Si is calculated.

[0041] As shown in Figure 5, this bond energy distribution defines the relationship between the bond energy of the main skeleton component and the intensity of that bond energy. The intensity of the bond energy is the number of detected photoelectrons having a specific bond energy. Note that in Figure 5, the intensity is normalized by dividing it by the maximum value of that intensity. Also, the bond energy distribution shown in Figure 5 is a schematic diagram and does not represent actual measurement results. In the bond energy distribution of the first region A1 obtained in this manner, a bond energy value having an intensity half the maximum value of the bond energy intensity is identified. The smallest value of the identified bond energy values ​​is identified as a first representative value E1 of the bond energy in the first region A1.

[0042] After irradiating the first region A1 with X-rays, the outer surface 51 of the glass film 50 is ground in a direction parallel to the outer surface 51 using the same method as above. The grinding distance is equal to or greater than the dimension of the first region A1 in a direction perpendicular to the outer surface 51 of the glass film 50. In other words, this dimension is the penetration length of the X-rays. Furthermore, grinding is performed so that the ground surface after grinding is located closer to the element body 20 than the range of the first region A1, i.e., the range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50 before grinding. Then, X-rays are irradiated at any location on this ground surface. Therefore, the second region A2 is a location located closer to the element body 20 than the first region A1. Furthermore, the second region A2 is a region several nanometers deep from the X-ray irradiated location on the ground surface. The binding energy distribution of the main skeleton components of the second region A2 is calculated using the same method as for the first region A1. Then, in the bond energy distribution of the main skeleton components present in the second region A2, the bond energy values ​​having an intensity half the maximum value of the bond energy intensity are identified, and the smallest of the identified bond energy values ​​is identified as a second representative value E2 of the bond energies in the second region A2.

[0043] Therefore, the "bond energy of the main skeleton component" can be calculated in each of the first region A1 and the second region A2 by the above-mentioned method. Then, when the first representative value E1 of the bond energy in the first region A1 is smaller than the second representative value E2 of the bond energy in the second region A2 by 0.5 eV or more, it is determined that the bond energy of the main skeleton component in the first region A1 is smaller than the bond energy of the main skeleton component in the second region A2.

[0044] (Regarding the Manufacturing Method of Electronic Component of First Embodiment) 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 first drying step S19, an immersion step S20, a second drying step S21, a conductor application step S22, a curing step S23, and a plating step S24.

[0045] First, in forming the element body 20, in the laminate preparation step S11, a laminate is prepared, which is the element body 20 in the shape of a rectangular parallelepiped having six flat surfaces 22. 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. The unfired laminate is then fired at a high temperature to prepare the laminate.

[0046] Next, 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 22 of the laminate prepared in the laminate preparation process S11 and at the boundary portions between three adjacent flat surfaces 22. For example, the corners of the laminate are R-chamfered by barrel polishing, thereby forming curved surfaces at the boundary portions.

[0047] Next, a solvent introduction step S13 is performed. In the solvent introduction step S13, 2-propanol is introduced into the reaction vessel as a solvent. Next, a catalyst introduction step S14 is performed. In the catalyst introduction step S14, first, stirring of the solvent in the reaction vessel is started. Then, ammonia water is introduced into the reaction vessel as an aqueous solution containing a catalyst. The catalyst in this embodiment is hydroxide ions, and functions as a catalyst for promoting the hydrolysis of the metal alkoxide, which will be described later.

[0048] Next, an element introduction step S15 is performed. In this step S15, a plurality of element bodies 20 previously formed in the R-chamfering step S12 as described above are introduced into a reaction vessel. Next, a polymer introduction step S16 is performed. In this step S16, polyvinylpyrrolidone is introduced into the reaction vessel as a polymer. As a result, the polymer introduced into the reaction vessel is adsorbed onto the outer surface 21 of the element bodies 20.

[0049] Next, as shown in FIG. 6 , a metal alkoxide introduction step S17 is performed. In the metal alkoxide introduction step S17, liquid tetraethyl orthosilicate is introduced into the reaction vessel as the metal alkoxide. Note that tetraethyl orthosilicate is also called tetraethoxysilane. In this embodiment, the amount of metal alkoxide 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 introduced is calculated by multiplying the amount of metal alkoxide 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.

[0050] Next, the film-forming step S18 is performed. In the film-forming step S18, the stirring of the solvent, which was started in the solvent-adding step S13 described above, is continued for a predetermined time after the metal alkoxide is added to the reaction vessel in the metal alkoxide-adding step S17. This causes the metal alkoxide to be hydrolyzed by the hydroxide ions serving as a catalyst. When the metal alkoxide is hydrolyzed, the hydrolyzed metal alkoxide adheres to the surface of the element body 20. The metal alkoxides attached to the surface of the element body 20 then 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.

[0051] Next, a first drying step S19 is performed. In the first drying step S19, after the film forming step S18, the element body 20 is removed from the reaction vessel and dried. As a result, the sol-state glass film 50 is dried and becomes a gel-state glass film 50.

[0052] Next, the immersion step S20 is performed. In the immersion step S20, a solution containing at least one element selected from alkali metals and alkaline earth metals as an additive is first placed in a reaction vessel different from the reaction vessel used up to the film-forming step S18. In this embodiment, the solution is an aqueous solution containing a potassium oxide precursor. Then, the element body 20 having the gel-like glass film 50 is immersed in the solution. This causes the solution to adhere to the surface of the glass film 50. In the immersion step S20, the potassium oxide precursor as an additive adheres to the surface of the glass film 50. The amount of potassium oxide precursor adhering to the outer surface 51 of the glass film 50 depends on the concentration of the potassium oxide precursor in the solution prepared in the immersion step S20.

[0053] Next, as shown in Fig. 6, a second drying step S21 is performed. In the second drying step S21, the element body 20 immersed in the solution in the immersion step S20 is removed from the reaction vessel and dried. This causes the water in the solution adhering to the surface of the glass film 50 to volatilize. Meanwhile, the potassium oxide precursor contained in the solution precipitates on the outer surface 51 of the glass film 50.

[0054] 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 cover the entire first end face 22A and portions of the four side faces 22C of the glass film 50. The conductor paste is also applied to cover the entire second end face 22B and portions of the four side faces 22C of the glass film 50.

[0055] Next, a curing step S23 is performed. Specifically, in the curing step S23, the glass film 50 and the element body 20 to which the conductive paste has been applied are 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. As a result, within the glass film 50, the concentration of the potassium oxide precursor on the outer surface 51 side of the glass film 50 becomes higher than the concentration of the potassium oxide precursor on the element body 20 side. Note that the amount of potassium oxide diffusing into the glass film 50 at this time depends on the amount of potassium oxide precursor attached to the outer surface 51 of the glass film 50.

[0056] In the curing step S23, the element body 20 is heated to vaporize water and polymer from the gel-like glass film 50. This causes the glass film 50 covering the outer surface 21 of the element body 20 to be baked and hardened. Furthermore, in the curing step S23, the conductor paste applied in the conductor application step S22 is baked to form the first base electrode 61A and the second base electrode 62A.

[0057] 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 through-holes 71 extend 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 through-holes 72 connecting the second internal electrode 42 and the second base electrode 62A.

[0058] 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.

[0059] (Effects of the First Embodiment) (1-1) In the first embodiment, within the glass film 50, the bond energy of the main skeleton components on the outer surface 51 side of the glass film 50 is smaller than the bond energy of the main skeleton components on the element body 20 side of the glass film 50. That is, some of the bonds between the main skeleton components of the glass film 50 are broken. In other words, the glass network is looser on the outer surface 51 side of the glass film 50 than on the element body 20 side. This structure weakens the force that restricts the movement of the main skeleton components relative to each other. As a result, even if a physical impact is applied to the outer surface 51 of the glass film 50, the stress is easily dispersed due to the movement of the main skeleton components. That is, in the electronic component 10 of the above embodiment, cracks are less likely to occur in the glass film 50.

[0060] (1-2) In the first embodiment, the glass network on the outer surface 51 side of the glass film 50 is loose, and the glass network on the element body 20 side is stronger than that on the outer surface 51 side. Therefore, cracks are less likely to occur on the outer surface 51 side of the glass film 50. Furthermore, on the element body 20 side of the glass film 50, the strong glass network makes it easier to prevent liquids such as plating solutions from penetrating into the element body 20 side of the glass film 50.

[0061] (1-3) In the first embodiment, the main skeleton component is silicon dioxide. This allows the electronic component 10 to be manufactured relatively inexpensively. (1-4) In the first embodiment, the glass film 50 contains one or more elements selected from alkali metals and alkaline earth metals as additives. The alkali metals and alkaline earth metals have the effect of disrupting the bonds between the oxides that are the main skeleton components. This allows the electronic component 10 to be manufactured with a loose glass network on the outer surface 51 side of the glass film 50.

[0062] (1-5) In the first embodiment, the difference between the average content ratio of the additives in the range 10 nm from the boundary line B toward the outer surface 51 of the glass film 50 and the average content ratio of the additives in the range 10 nm from the boundary line B toward the element body 20 is less than 40%. That is, from the perspective of the strength of the glass network inside the glass film 50, no clear interface exists inside the glass film 50. This eliminates the risk of interfacial delamination between the strong layer and the loose layer of the glass network.

[0063] (1-6) In the first embodiment, the average content of the additive is 10% or more in a range of 1% to 90% of the thickness TG from the outer surface 51 of the glass film 50. That is, the range in which the glass network is somewhat loosened due to the presence of the additive exists across most of the thickness of the glass film 50. This allows the entire glass film 50 to absorb impact, thereby effectively preventing cracks from occurring in the glass film 50.

[0064] (1-7) In the first embodiment, the average additive content is 20% to 40% in the range of 5% to 20% of the thickness TG from the outer surface 51 of the glass film 50. When the average additive content is higher than 20%, the glass network tends to become loose. That is, physical impacts applied to the outer surface 51 of the glass film 50 are easily buffered. Moreover, since such a layer with a loose glass network exists near the outer surface 51 of the glass film 50, impacts from the outer surface 51 side are effectively prevented. On the other hand, when the average additive content is higher than 40%, the proportion of broken bonds between oxides in the main framework component increases. That is, there is a risk of a decrease in barrier properties against the penetration of liquids such as plating solutions. Therefore, the average additive content is preferably 20% to 40%.

[0065] Second Embodiment of Electronic Component Next, a second embodiment of the electronic component will be described. The configuration of the electronic component 10 according to the second embodiment is the same as the configuration of the electronic component 10 according to the first embodiment. Therefore, the configuration of the electronic component according to the second embodiment will be described below using the same reference numerals as the configuration of the electronic component 10 according to the first embodiment.

[0066] The method for manufacturing electronic component 10 according to the second embodiment differs from the method for manufacturing electronic component 10 according to the first embodiment in that it does not perform the immersion step S20 and the second drying step S21. The method for manufacturing electronic component 10 according to the second embodiment also differs from the method for manufacturing electronic component 10 according to the first embodiment in that it performs the coupling agent injection step S119.

[0067] 7, the method for manufacturing electronic component 10 according to the second embodiment includes a laminate preparation step S111, an R-chamfering step S112, a solvent introduction step S113, a catalyst introduction step S114, an element introduction step S115, a polymer introduction step S116, and a metal alkoxide introduction step S117. The method for manufacturing electronic component 10 according to the second embodiment also includes a film formation step S118, a coupling agent introduction step S119, a first drying step S120, a conductor application step S121, a curing step S122, and a plating step S123.

[0068] The laminate preparation step S111 to the film formation step S118 in the second embodiment are the same as the laminate preparation step S11 to the film formation step S18 in the first embodiment. Furthermore, the first drying step S120 to the plating step S123 in the second embodiment are the same as the first drying step S19 and the conductor application step S22 to the plating step S24 in the first embodiment.

[0069] In the second embodiment, a coupling agent introduction step S119 is performed after the start of the film formation step S118 and before the first drying step S120. In the coupling agent introduction step S119 of this embodiment, the coupling agent is introduced into the reaction vessel at predetermined time intervals while the inside of the reaction vessel is being stirred for a predetermined time in the film formation step S118. That is, in the coupling agent introduction step S119, the coupling agent is introduced stepwise in multiple installments rather than all at once.

[0070] By adding a coupling agent in the coupling agent adding step S119, in the sol-state glass film 50, bonds are formed between the constituent elements of the main skeleton component as well as between the constituent elements and the coupling agent. That is, adding the coupling agent loosens the glass network. For example, when the main skeleton component is silicon dioxide, a silane coupling agent is added as the coupling agent in the coupling agent adding step S119. At this time, the silane coupling agent bonds to replace some of the oxygen atoms in the network structure formed by the main skeleton component. Therefore, the network structure of the glass film 50 having silicon dioxide as the main skeleton component contains not only siloxane bonds between silicon atoms and oxygen atoms but also crosslinked structures formed by the silane coupling agent. Therefore, compared to a pure network structure composed only of silicon dioxide, the network structure of the glass film 50 that has undergone the coupling agent adding step S119 has a looser glass network.

[0071] In this embodiment, a coupling agent introduction step S119 is performed during the film formation step S118. By introducing the coupling agent while the glass film 50 is being formed, the coupling agent is more likely to bond to the main skeleton component inside the glass film 50. Furthermore, by introducing the coupling agent in stages, the concentration of the coupling agent in the reaction vessel gradually increases. Therefore, as the formation of the glass film 50 progresses, the coupling agent is more likely to bond to the main skeleton component, and the glass network on the outer surface 51 side of the glass film 50 becomes looser. Therefore, the magnitude of the bond energy of the main skeleton component in the first region A1 can be made smaller than the magnitude of the bond energy of the main skeleton component in the second region A2.

[0072] Therefore, in the electronic component 10 according to the second embodiment manufactured in this manner, the bond energy of the main skeleton components in the first region A1 is smaller than the bond energy of the main skeleton components in the second region A2. In other words, the glass network in the first region A1 is looser than the glass network in the second region A2.

[0073] (Effects of the Second Embodiment) According to the second embodiment, the effects (1-1) to (1-7) described in the first embodiment can be obtained in the same way.

[0074] <Comparative Test Results of Electronic Components According to Each Example> A comparative test was conducted to evaluate the barrier properties of the glass film 50 of the electronic components 10 of Examples 1 to 3 and the glass film of the electronic component of Comparative Example 1.

[0075] The electronic component 10 of Example 1 is the same as that described in the first embodiment. That is, in the electronic component 10 of Example 1, the magnitude of the bond energy of the main skeletal component in the first region A1 is smaller than the magnitude of the bond energy of the main skeletal component in the second region A2.

[0076] The structure of electronic component 10 of Example 2 is the same as that described in Embodiment 2. That is, in electronic component 10 of Example 2, the magnitude of the bond energy of the main skeletal component in first region A1 is smaller than the magnitude of the bond energy of the main skeletal component in second region A2.

[0077] The main skeleton component of the glass film 50 of the electronic component 10 of Example 2 is silicon dioxide. Furthermore, the electronic component 10 of Example 2 was manufactured by adding a silane coupling agent to the reaction vessel in the coupling agent adding step S119.

[0078] The basic structure of electronic component 10 of Example 3 is similar to that described in Embodiment 2. That is, in electronic component 10 of Example 3, the magnitude of the bond energy of the main skeletal component in first region A1 is smaller than the magnitude of the bond energy of the main skeletal component in second region A2.

[0079] However, in the glass film 50 of the electronic component 10 of Example 3, the main skeleton component was zirconia (ZrO ２ ) Furthermore, electronic component 10 of Example 3 was manufactured by adding a zirconate coupling agent to the reaction vessel in coupling agent adding step S119.

[0080] The basic structure of the electronic component of Comparative Example 1 is similar to that described in the first embodiment. However, the electronic component of Comparative Example 1 was manufactured without performing the immersion step S20 and the second drying step S21. That is, the glass film of the electronic component of Comparative Example 1 does not contain any additives. Therefore, in the electronic component of Comparative Example 1, the magnitude of the bond energy of the main skeleton component in the first region A1 is approximately the same as the magnitude of the bond energy of the main skeleton component in the second region A2.

[0081] In the comparative test, first, multiple electronic components are placed in a sealed container. The sealed container is then swung for a predetermined time, causing the electronic components to collide with each other within the sealed container. After that, all electronic components are removed from the sealed container, and a 100 μm square area of ​​the outer surface of the glass film of each electronic component is observed using a scanning electron microscope (SEM). It is then determined whether cracks have occurred on the outer surface of the glass film. Next, external electrodes are formed on the outer surface of the glass film using the manufacturing method described above. The ground cross section perpendicular to the outer surface of the element body is then observed, and it is determined whether the plating solution has penetrated into the glass film. The element body is ground using focused ion beam processing, as in the method described above.

[0082] As a result of the comparative tests for Examples 1 to 3 and Comparative Example 1, in the electronic component 10 of Example 1, no cracks were observed on the outer surface 51 of the glass film 50. Furthermore, infiltration of the plating solution into the glass film 50 was not observed. In the electronic component 10 of Example 2, no cracks were observed on the outer surface 51 of the glass film 50. Furthermore, infiltration of the plating solution into the glass film 50 was not observed. In the electronic component 10 of Example 3, no cracks were observed on the outer surface 51 of the glass film 50. Furthermore, infiltration of the plating solution into the glass film 50 was not observed. In the electronic component of Comparative Example 1, cracks were observed on the outer surface of the glass film. Furthermore, infiltration of the plating solution into the glass film was observed.

[0083] Therefore, as is clear from the results of the comparative tests, cracks are less likely to occur on the outer surface 51 side of the glass film 50 in the electronic components 10 of Examples 1 to 3. Furthermore, the glass network is strong on the element body 20 side of the glass film 50. Therefore, cracks are suppressed on the outer surface 51 side of the glass film 50, and penetration of liquids such as plating solutions can be suppressed on the element body 20 side of the glass film 50.

[0084] <Modifications> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined and implemented within the scope of technical compatibility.

[0085] In the above embodiment, the electronic component 10 is not limited to a negative temperature coefficient thermistor component. For example, the electronic component 10 may be a thermistor component other than a negative temperature coefficient thermistor component, a multilayer capacitor component, or an inductor component, as long as it has some kind of wiring inside the element body 20.

[0086] The material of the element body 20 is not limited to the example of the above embodiment. The material of the element body 20 may be a composite body of resin and metal powder. The shape of the element body 20 is not limited to the example of 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.

[0087] The boundary portion between adjacent flat surfaces 22 of 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. In the above embodiment, the shapes of the first internal electrodes 41 and the second internal electrodes 42 are not important as long as they can 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.

[0088] 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.

[0089] The first base electrode 61A does not have to contain glass as long as it is electrically connected to the first internal electrode 41. Similarly, the second base electrode 62A does not have to contain glass as long as it is electrically connected to the second internal electrode 42.

[0090] In the above embodiment, the combination of materials for 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.

[0091] 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 exposed prior to the external electrode formation process. For example, the first end surface 22A side of the element body 20 may be polished to physically remove a portion of the glass film 50. The base electrode formation process 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.

[0092] 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.

[0093] The glass film 50 does not have to cover substantially 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.

[0094] In the portion of the glass film 50 that is covered with the first base electrode 61A, the glass in the glass film 50 may diffuse into the glass in the first base electrode 61A, thereby integrating the two.

[0095] When the glass film 50 contains one or more elements selected from alkali metals and alkaline earth metals as additives, the ratio of the additives to the Si contained in the glass film 50 may be less than 0.5 atm % or greater than 90 atm %.

[0096] The additive is not limited to potassium and may be changed as appropriate depending on the type of main framework component. For example, the additive may be lithium, sodium, rubidium, cesium, magnesium, calcium, strontium, barium, etc. Furthermore, the additive does not have to be an alkali metal or an alkaline earth metal. For example, the additive may be scandium, zinc, gallium, yttrium, cadmium, indium, tin, mercury, lead, lanthanum, thorium, etc.

[0097] The method for defining the first region A1 and the second region A2 is not limited to the example in the above embodiment. These regions can be defined as appropriate as long as the condition that the second region A2 is located closer to the element body 20 than the first region A1 is satisfied. Furthermore, the relationship that the magnitude of the bond energy of the main skeleton component in the first region A1 is smaller than the magnitude of the bond energy of the main skeleton component in the second region A2 can be determined arbitrarily. In other words, it is sufficient that this relationship is satisfied in at least one pair of the above regions.

[0098] The method for calculating the bond energy of the main skeleton component is not limited to the example in the above embodiment. For example, the correspondence relationship between the concentration of the additive and the bond energy of the main skeleton component may be determined by EDX and XPS. Then, the concentration of the additive in the first region A1 and the second region A2 may be measured by EDX analysis, thereby indirectly determining the bond energy of the main skeleton component.

[0099] In the ground cross section of the element body 20 described in the above embodiment, the difference between the average content of the additives in a range of 10 nm from the boundary line B toward the outer surface 51 of the glass film 50 and the average content of the additives in a range of 10 nm from the boundary line B toward the element body 20 needs to be less than 40% for at least one boundary line B. Even in this case, there is no clear boundary due to the magnitude of the bond energy within a range of ±10 nm from the boundary line B in a direction perpendicular to the outer surface. Furthermore, the difference in the average content may always be 40% or more. Even in this case, cushioning against physical impacts can be obtained on the outer surface 51 side of the glass film 50.

[0100] Within a range of 1% to 90% of the thickness T from the outer surface 51 of the glass film 50, there may be a location where the average additive content is less than 10%, or there may be no location where the average additive content is 10% or more within that range. Furthermore, within a range of 5% to 20% of the thickness T from the outer surface 51 of the glass film 50, there may be a location where the average additive content is less than 20% and a location where the average additive content is greater than 40%. Furthermore, within a range of 5% to 20% of the thickness T from the outer surface 51 of the glass film 50, there may be no location where the average additive content is 20% to 40%. Regardless of the average additive content, it is sufficient that the magnitude of the bond energy in the first region A1 is smaller than the magnitude of the bond energy in the second region A2.

[0101] The main skeleton component of the glass film 50 is not limited to silicon dioxide. Furthermore, 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 a B-Si-based, Si-Zn-based, Zr-Si-based, or Al-Si-based oxide. Furthermore, the glass may be a multi-component oxide containing an alkali metal and Si, such as an Al-Si-based, Na-Si-based, or Li-Si-based oxide. Furthermore, the glass may be a multi-component oxide containing an alkaline earth metal and Si, such as an Mg-Si-based, Ca-Si-based, Ba-Si-based, or Sr-Si-based oxide. Furthermore, the glass may not contain Si, and may be a mixture thereof.

[0102] 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.

[0103] The additive contained in the solution introduced into the reaction vessel in the immersion step S20 is not limited to the potassium oxide precursor. Specifically, 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. The additive may also include calcium acetate, calcium gluconate, calcium citrate, calcium malate, calcium lactate, calcium benzoate, calcium stearate, or calcium aspartate.

[0104] Furthermore, for example, the additive contained in the solution 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.

[0105] Also for example, the additive may be boron triiodide, sodium cyanoborohydride, sodium borohydride, tetrafluoroboric acid, triethylborane, borax, or boric acid.

[0106] 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.

[0107] 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.

[0108] 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.

[0109] In the second embodiment, the amount of silane coupling agent added per predetermined time may be increased as the number of times the agent is added increases. Also, the predetermined time may be shortened as the number of times the agent is added increases.

[0110] The manufacturing method is not limited to the methods of the first and second embodiments. For example, the immersion step S20 and the second drying step S21 may not be performed, and instead, after the first drying step S19, chemical etching, plasma irradiation, ultraviolet irradiation, electron beam irradiation, ozone irradiation, or the like may be performed on the outer surface 51 of the glass film 50. In other words, by applying a physical load to the outer surface 51 side of the glass film 50, the magnitude of the bond energy of the main skeleton component in the first region A1 can be made smaller than the magnitude of the bond energy of the main skeleton component in the second region A2.

[0111] In the manufacturing method of the first embodiment, the precipitation and inward diffusion of the potassium oxide precursor may not be performed in the hardening step S23. For example, a firing step of firing the element body 20 may be performed after the second drying step S21 and before the conductor application step S22. This firing turns the potassium oxide precursor precipitated in the second drying step S21 into potassium oxide. The potassium oxide diffuses into the glass film 50 covering the outer surface 21 of the element body 20. This may be followed by the conductor application step S22, and the conductor paste may be hardened in the hardening step S23. In this case, the method of hardening the conductor paste is not limited to heating. For example, if a material that hardens when exposed to ultraviolet light is used as the conductor paste, the conductor paste may be hardened by ultraviolet light irradiation.

[0112] In the second embodiment, the coupling agent introduction step S119 may be performed after the start of the film formation step S118 and before the first drying step S120. That is, the coupling agent introduction step S119 does not have to be performed during the film formation step S118. The coupling agent introduction step S119 may be performed after the film formation step S118.

[0113] <Supplementary Notes> The technical ideas that can be understood from the above embodiments and modified examples will be described below. [1] An electronic component comprising an element body and a glass film covering an outer surface of the element body, wherein the glass film contains an oxide of one or more elements selected from boron, aluminum, silicon, phosphorus, titanium, vanadium, gallium, germanium, arsenic, zirconium, molybdenum, antimony, and tungsten, wherein the oxide contained in the glass film with the greatest content is a main skeleton component of the glass film, and wherein an arbitrary location inside the glass film is defined as a first region and a location inside the glass film that is closer to the element body than the first region is defined as a second region, wherein the magnitude of the bond energy of the main skeleton component in the first region is smaller than the magnitude of the bond energy of the main skeleton component in the second region.

[0114] [2] The electronic component according to [1], wherein the main skeleton component is an oxide of silicon. [3] The electronic component according to [1] or [2], wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as additives, and the average content of the additives in the first region is greater than the average content of the additives in the second region.

[0115] [4] The electronic component according to [3], wherein when the glass film is viewed in cross section perpendicular to the outer surface of the element body, and a boundary line is drawn in the cross section of the glass film at any point between a point 10 nm away from the outer surface of the glass film and a point 10 nm away from the outer surface of the element body in a direction perpendicular to the outer surface of the glass film, the difference between the average content rate of the additive within a range of 10 nm from the boundary line in a direction perpendicular to the boundary line and toward the outer surface of the glass film, and the average content rate of the additive within a range of 10 nm from the boundary line in a direction perpendicular to the boundary line and toward the element body is less than 40%.

[0116] [5] An electronic component according to any one of [1] to [4], wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as an additive, and when the dimension of the glass film in a direction perpendicular to the outer surface of the element body is defined as the thickness of the glass film, the average content of the additive is 3% or more within a range of 1% to 90% of the thickness from the outer surface of the glass film.

[0117] [6] An electronic component according to any one of [1] to [5], wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as an additive, and when the dimension of the glass film in a direction perpendicular to the outer surface of the element body is defined as the thickness of the glass film, the average content of the additive is 20% or more and 40% or less in a range of 5% or more and 20% or less of the thickness from the outer surface of the glass film.

[0118] 10... Electronic component 20... Element body 21... Outer surface 41... First internal electrode 42... Second internal electrode 50... Glass film 51... Outer surface TG... Thickness B... Boundary line A1... First region A2... Second region

Claims

1. An electronic component comprising: an element body; and a glass film covering an outer surface of the element body, wherein the glass film contains an oxide of one or more elements selected from boron, aluminum, silicon, phosphorus, titanium, vanadium, gallium, germanium, arsenic, zirconium, molybdenum, antimony, and tungsten; wherein the oxide contained in the glass film with the greatest content is a main skeleton component of the glass film; wherein an arbitrary location inside the glass film is defined as a first region; and a location inside the glass film located on the element body side of the first region is defined as a second region; and wherein the magnitude of the bond energy of the main skeleton component in the first region is smaller than the magnitude of the bond energy of the main skeleton component in the second region.

2. The electronic component according to claim 1, wherein the main skeleton component is an oxide of silicon.

3. An electronic component according to claim 1 or claim 2, wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as additives, and the average content of the additives in the first region is greater than the average content of the additives in the second region.

4. The electronic component according to claim 3, wherein when the glass film is viewed in cross section perpendicular to the outer surface of the element body, and a boundary line is drawn in the cross section of the glass film extending in a direction along the outer surface of the glass film at any point between a point 10 nm away from the outer surface of the glass film in a direction perpendicular to the outer surface of the glass film and a point 10 nm away from the outer surface of the element body, the difference between the average content rate of the additive within a range of 10 nm from the boundary line in a direction perpendicular to the boundary line and toward the outer surface of the glass film, and the average content rate of the additive within a range of 10 nm from the boundary line in a direction perpendicular to the boundary line and toward the element body is less than 40%.

5. An electronic component according to any one of claims 1 to 4, wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as an additive, and when the dimension of the glass film in a direction perpendicular to the outer surface of the element body is defined as the thickness of the glass film, the average content of the additive is 3% or more within a range of 1% to 90% of the thickness from the outer surface of the glass film.

6. An electronic component according to any one of claims 1 to 5, wherein the glass film contains one or more elements selected from alkali metals and alkaline earth metals as an additive, and when the dimension of the glass film in a direction perpendicular to the outer surface of the element body is defined as the thickness of the glass film, the average content of the additive is 20% to 40% within a range of 5% to 20% of the thickness from the outer surface of the glass film.

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