Electronic Components

Abstract

This disclosure provides an electronic component (10) for which the peeling of an insulation film (50) from a base body (20) is prevented. The electronic component (10) comprises a base body (20) and an insulation film (50) that covers an outer surface (21) of the base body (20). The insulation film (50) includes a mixed layer (51) and a glass layer (56). The mixed layer (51) includes glass (52) and a powdered material (53). The glass layer (56) includes glass (57) and contains the powdered material (53) at a ratio smaller than that of the mixed layer (51). The mixed layer (51) is located, as seen from the glass layer (56), on the base body (20) side.

Description

[Technical field]

[0001] The present invention relates to electronic components. [Background technology]

[0002] The electronic component described in Patent Document 1 includes an element body and an insulating film that covers the outer surface of the element body. The insulating film is a glass layer made of glass. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2002-043167 A Summary of the Invention [Problem to be solved by the invention]

[0004] The electronic component described in Patent Document 1 may be subjected to an external impact. When an external impact is applied to the electronic component, the load due to the impact and the internal stress of the glass layer may combine to cause a large force to act on a specific location in the glass layer. When a large force acts on the glass layer, a part of the glass layer may peel off from the outer surface of the element body. [Means for solving the problem]

[0005] In order to solve the above-mentioned problems, the present invention provides an electronic component comprising an element body and an insulating film covering an outer surface of the element body, the insulating film having a mixed layer containing glass and powder-granular material, and a glass layer containing glass and having a smaller powder-granular material content than the mixed layer, the mixed layer being located on the element body side as viewed from the glass layer.

[0006] According to the above configuration, the insulating film has a mixed layer and a glass layer. The mixed layer contains glass and powder and granular material. In the mixed layer, the content of the powder and granular material is larger than that in the glass layer, and therefore the internal stress of the glass is alleviated. Furthermore, since the internal stress of the glass is divided into each powder and granular material at each location where the powder and granular material are present, large internal stress is unlikely to concentrate and act on a specific location. Therefore, when an external impact is applied to the electronic component, it is possible to suppress the insulating film from peeling off from the element body due to the internal stress. Effect of the Invention

[0007] This can prevent the insulating film from peeling off from the element body. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] Cross-sectional view taken along line 3-3 in Figure 2. [Figure 4] An enlarged cross-section along line 4-4 in Figure 2. [Diagram 5] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 6] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 7] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 8] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 9] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 10] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 11] FIG. 13 is an enlarged cross-sectional view of an electronic component according to a modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] <An embodiment of the electronic component> Hereinafter, an embodiment of an 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 the actual ones or from those in other drawings. In addition, although hatching is applied in the cross-sectional views, hatching of some components may be omitted to facilitate understanding.

[0010] (Overall structure) 1, 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 a characteristic that its resistance value decreases as the temperature increases.

[0011] 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 defined as a first axis X. One of the axes perpendicular to the first axis X is defined as a second axis Y. An axis perpendicular to the first axis X and the second axis Y is defined as a third axis Z. One of the directions along the first axis X is defined as a first positive direction X1, and the direction along the first axis X opposite to the first positive direction X1 is defined as a first negative direction X2. One of the directions along the second axis Y is defined as a second positive direction Y1, and the direction along the second axis Y opposite to the second positive direction Y1 is defined as a second negative direction Y2. One of the directions along the third axis Z is defined as a third positive direction Z1, and the direction along the third axis Z opposite to the third positive direction Z1 is defined as a third negative direction Z2.

[0012] The outer surface 21 of the element body 20 has six planar planes 22. The six planes 22 extend in different directions. The six planes 22 are roughly divided into a first end face 22A facing the first positive direction X1, a second end face 22B facing the first negative direction X2, and four side faces 22C. The four side faces 22C are a face facing the third positive direction Z1, a face facing the third negative direction Z2, a face facing the second positive direction Y1, and a face facing the second negative direction Y2, respectively.

[0013] The outer surface 21 of the element body 20 has twelve boundary surfaces 23. The boundary surfaces 23 include curved surfaces that exist at the boundaries between adjacent flat surfaces 22. That is, the boundary surfaces 23 include curved surfaces that are formed, for example, by R-chamfering the corners that form the adjacent flat surfaces 22.

[0014] Furthermore, the outer surface 21 of the element body 20 has eight spherical corner surfaces 24. The corner surfaces 24 are boundary portions between three adjacent flat surfaces 22. In other words, the corner surfaces 24 include curved surfaces at the intersections of the three boundary surfaces 23. That is, the corner surfaces 24 include curved surfaces formed, for example, by R-chamfering the corners formed by the three adjacent flat surfaces 22.

[0015] 1 and 2, the surface of an insulating film 50, which will be described later, is regarded as being the same as the outer surface 21 of the element body 20 and is given a reference symbol. As shown in Fig. 2, element body 20 has a larger dimension along first axis X than along third axis Z. Also, as shown in Fig. 1, element body 20 has a larger dimension along first axis X than along second axis Y. Also, the material of element body 20 is ceramics obtained by firing a metal oxide containing at least one of Mn, Fe, Ni, Co, Ti, Ba, Al, and Zn.

[0016] 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.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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.

[0021] As shown in Fig. 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.

[0022] 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.

[0023] The electronic component 10 includes an insulating film 50. The insulating film 50 covers the outer surface 21 of the element body 20. In this embodiment, the insulating film 50 covers the entire area of ​​the outer surface 21 of the element body 20.

[0024] 3, 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 insulating 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 in the first positive direction X1. In this embodiment, the first base electrode 61A is made of silver and glass.

[0025] The first metal layer 61B covers the first base electrode 61A from the outside. Therefore, the first metal layer 61B is laminated on the first base electrode 61A. Specifically, the first metal layer 61B has a two-layer structure of nickel plating and tin plating.

[0026] 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 insulating 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 on the first negative direction X2 side. In this embodiment, the material of the second base electrode 62A is the same as the material of the first external electrode 61, that is, silver and glass.

[0027] The second metal layer 62B covers the second base electrode 62A from the outside. Therefore, the second metal layer 62B is 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.

[0028] The second external electrode 62 does not reach the first external electrode 61 on the side surface 22C, and is disposed apart from the first external electrode 61 in the direction along the first axis X. In addition, in the central portion of the side surface 22C of the element body 20 in the direction along the first axis X, the first external electrode 61 and the second external electrode 62 are not laminated, and the insulating film 50 is exposed. Note that in Figs. 1 to 3, the first external electrode 61 and the second external electrode 62 are illustrated by two-dot chain lines.

[0029] 3, the first external electrode 61 and the end of the first internal electrode 41 on the first positive direction X1 side are connected to each other via a first penetrating portion 71 that penetrates the insulating film 50. Note that, as will be described in detail later, the first penetrating 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 side.

[0030] 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 insulating film 50. Like 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, although FIG. 3 illustrates the first internal electrode 41 and the first through portion 71 as separate members with a boundary, in reality, there is no clear boundary between them. The same applies to the second through portion 72. Also, the first through portion 71 is not illustrated in FIGS. 1 and 2.

[0031] (Insulating film) 4, the insulating film 50 has a mixed layer 51 and a glass layer 56. The mixed layer 51 contains glass 52 and powder / granular material 53. The mixed layer 51 is laminated on the outer surface 21 of the element body 20. That is, the mixed layer 51 covers the outer surface 21 of the element body 20 without any other layer therebetween. The mixed layer 51 is located on the element body 20 side as viewed from the glass layer 56.

[0032] When the mixed layer 51 is viewed in cross section, the powder particles 53 are dispersed in the glass 52. The material of the powder particles 53 is the same as that of the element body 20. The thermal expansion coefficient of the powder particles 53 is greater than that of the glass 52. The average particle size of the powder particles 53 is 100 nm or more. The average particle size may be calculated as the average value of the particle sizes of a plurality of powder particles 53, for example, 10 powder particles 53, randomly extracted in one image viewed in cross section. The powder particles 53 may be agglomerated into one mass of a plurality of particles. In this case, if the interface of particles can be observed inside the aggregated mass, the portion surrounded by the boundary is one powder particle 53. The particle size is the maximum dimension passing through the geometric center of one powder particle 53 when the powder particle 53 is viewed in cross section.

[0033] The glass layer 56 is a layer in which the content of powder / granular material 53 is smaller than that of the mixed layer 51. In this embodiment, the glass layer 56 is composed substantially only of glass 57. Note that the glass 57 of the glass layer 56 and the glass 52 of the mixed layer 51 are integrated with each other and do not have a clear boundary line.

[0034] The glass layer 56 has a crack 58. The crack 58 opens on the surface of the glass layer 56 opposite to the mixed layer 51. The crack 58 does not reach the element body 20. The tip of the crack 58 is present in the mixed layer 51. Therefore, the powder granules 53 are present near the tip of the crack 58. As described above, the mixed layer 51 contains the glass 52 and the powder granules 53. The thermal expansion coefficient of the powder granules 53 is greater than that of the glass 52. Therefore, when the mixed layer 51 is heated, the portion of the glass 52 near the powder granules 53 receives a force from the powder granules 53 which is about to expand. Due to such a force, the crack 58 occurs in the insulating film 50, particularly in the glass 52 near the powder granules 53.

[0035] In a cross-sectional view perpendicular to the outer surface 21 of the element body 20, the powder / granule material 53 furthest from the outer surface 21 of the element body 20 is defined as a specific powder / granule material 53S. A point of the specific powder / granule material 53S furthest from the outer surface 21 of the element body 20 is defined as a specific point P. The shortest distance from the outer surface 21 of the element body 20 to the specific point P is defined as a first thickness T1. The shortest distance from the specific point P to the surface of the glass layer 56 covering the powder / granule material 53 is defined as a second thickness T2. In this case, the first thickness T1 is greater than the second thickness T2.

[0036] <One embodiment of a method for manufacturing an electronic component> (Overall structure) Next, a method for manufacturing the electronic component 10 will be described.

[0037] 5, the method for producing electronic component 10 includes a laminate preparation step S11, a 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 producing electronic component 10 also includes a film formation step S18, a drying step S19, a conductor application step S20, a curing step S21, and a plating step S22.

[0038] First, in forming the element body 20, in the laminate preparation step S11, a laminate that is the element body 20 that does not have the boundary surface 23 and the corner surface 24 is prepared. That is, the laminate is in a state before R chamfering and has a rectangular parallelepiped shape having six planes 22. For example, first, a plurality of ceramic sheets that will become the element body 20 are prepared. The sheets are thin plate-like. 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 conductive paste. A conductive paste that will become the second internal electrode 42 is laminated on the sheets. In this way, the ceramic sheet and the conductive paste are laminated. Then, the laminate is cut to a predetermined size to form an unfired laminate. After that, the unfired laminate is fired at a high temperature to prepare a laminate.

[0039] Next, a R-chamfering process S12 is performed. In the R-chamfering process S12, a boundary surface 23 and a corner surface 24 are formed on the laminate prepared in the laminate preparation process S11. For example, the corners of the laminate are R-chamfered by barrel polishing, thereby forming a boundary surface 23 having a curved surface and a corner surface 24 having a curved surface. In this way, an element body 20 is formed. Also, a part of the ceramic sheet that constituted the laminate adheres to an outer surface 21 of the element body 20 as powder or granular material 53. Therefore, the material of the powder or granular material 53 is the same as that of the element body 20.

[0040] Next, a solvent introduction step S13 is performed. As shown in Fig. 6, in the solvent introduction step S13, 2-propanol is introduced into a reaction vessel 81 as a solvent 82. Next, a catalyst introduction step S14 is performed as shown in Fig. 5. As shown in Fig. 7, 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 a hydroxide ion, and functions as a catalyst for promoting hydrolysis of a metal alkoxide 85 described later.

[0041] Next, an element body charging step S15 is performed as shown in Fig. 5. As shown in Fig. 8, in the element body charging step S15, a plurality of element bodies 20 formed in advance in the R chamfering step S12 as described above are charged into a reaction vessel 81.

[0042] Next, a polymer introduction step S16 is performed as shown in Fig. 5. As shown in Fig. 9, in the polymer introduction step S16, polyvinylpyrrolidone is introduced into a reaction vessel 81 as a polymer 84. As a result, the polymer 84 introduced into the reaction vessel 81 is adsorbed onto the outer surface 21 of the element body 20.

[0043] Next, as shown in Fig. 5, a metal alkoxide introduction step S17 is performed. As shown in Fig. 10, 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 body 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 insulating film 50 covering the outer surface 21 of the element body 20 by the number of element bodies 20.

[0044] 5, a film-forming step S18 is performed. In the film-forming step S18, the stirring of the solvent 82 started in the above-mentioned solvent introducing step S13 is continued for a predetermined time after the metal alkoxide 85 is introduced into the reaction vessel 81 in the metal alkoxide introducing step S17.

[0045] Next, a drying step S19 is performed. In the drying step S19, after stirring is continued for a predetermined time in the film forming step S18, the element body 20 is removed from the reaction vessel 81 and dried. As a result, the sol-like insulating film 50 is dried to become a gel-like insulating film 50. At this time, the glass 52 grows so as to cover the powder particles 53 attached to the outer surface 21 of the element body 20 in particular. Therefore, the insulating film 50 having the mixed layer 51 and the glass layer 56 is formed. In this embodiment, the film forming method for forming the insulating film 50 on the element body 20 is configured by the solvent introduction step S13, the catalyst introduction step S14, the element introduction step S15, the polymer introduction step S16, the metal alkoxide introduction step S17, and the film forming step S18.

[0046] Next, a conductor application step S20 is performed. In the conductor application step S20, a conductor paste is applied to two locations on the surface of the insulating 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 so as to cover the insulating film 50 over the entire first end face 22A and parts of the four side faces 22C. The conductor paste is also applied so as to cover the insulating film 50 over the entire second end face 22B and parts of the four side faces 22C.

[0047] Next, a curing step S21 is performed. Specifically, in the curing step S21, the element body 20 on which the insulating film 50 and the conductor paste are applied is heated. As a result, water and polymer 84 are vaporized from the gel insulating film 50, and the insulating film 50 covering the outer surface 21 of the element body 20 is baked and hardened as shown in FIG. 3. At the same time, the conductor paste applied in the conductor application step S20 is baked to form the first base electrode 61A and the second base electrode 62A. In this way, the conductor application step S20 and the curing step S21 constitute a base electrode formation step. That is, in this embodiment, the curing step S21 is not only a step for hardening the insulating film 50, but also serves as a part of the base electrode formation step.

[0048] In this embodiment, during heating in the curing step S21, the Kirkendall effect caused by the difference in diffusion speed between the first internal electrode 41 and the first base electrode 61A attracts palladium contained in the first internal electrode 41 to the first base electrode 61A containing silver. As a result, the first through portion 71 extends from the first internal electrode 41 toward the first base electrode 61A through the insulating film 50, thereby connecting the first internal electrode 41 to the first base electrode 61A. The same applies to the second through portion 72 connecting the second internal electrode 42 to the second base electrode 62A.

[0049] Next, a plating step S22 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. Also, 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.

[0050] (Operation of the embodiment) Suppose that the insulating film 50 is made only of glass 57. In this case, internal stresses at various points of the glass 57 may combine to generate large internal stress at specific points. Therefore, when an external impact is applied, the external impact and the internal stress are superimposed, causing the glass 57 to deform. As a result, a crack may develop in the glass 57 or the glass 57 may bend in the thickness direction, causing the glass 57 to peel off from the outer surface 21 of the element body 20.

[0051] (Effects of the embodiment) (1) According to the above embodiment, the insulating film 50 includes the mixed layer 51 and the glass layer 56. The mixed layer 51 contains the glass 52 and the powder / granule material 53. Therefore, the mixed layer 51 contains the powder / granule material 53 in a larger proportion than the glass layer 56, and therefore the internal stress of the glass 52 is alleviated. Furthermore, minute gaps are likely to occur in each location where the powder / granule material 53 is present. Specifically, minute gaps are generated between particles in the powder / granule material 53 and between the powder / granule material 53 and the glass 52, resulting in locations where the adhesion is lower than the adhesion between the glass 52. Due to such minute gaps, the internal stress of the glass 52 is divided among the powder / granule material 53 in each location where the powder / granule material 53 is present, so that large internal stress is unlikely to concentrate and act on a specific location. Therefore, when an external impact is applied to the electronic component 10, it is possible to suppress the insulating film 50 from peeling off from the element body 20 due to the internal stress.

[0052] (2) If, during the manufacturing process, the first metal layer 61B and the second metal layer 62B are formed in a state in which the insulating film 50 has peeled off from the outer surface 21 of the element body 20, the plating solution that will become the first metal layer 61B and the second metal layer 62B will enter the area where the insulating film 50 has peeled off. This may cause the element body 20 to dissolve in the plating solution. According to the above embodiment, the insulating film 50 covers the entire outer surface 21 of the element body 20. Therefore, by preventing contact between the element body 20 and the plating solution, it is possible to prevent the element body 20 from dissolving in the plating solution in the plating step S22.

[0053] (3) According to the above embodiment, the material of powder and granular material 53 is the same as that of element body 20. Therefore, the effort of preparing a special material for powder and granular material 53 can be eliminated. Also, in the above embodiment, a part of the ceramic sheet generated in R chamfering process S12 is directly used as powder and granular material 53. Therefore, the effort of including powder and granular material 53 in insulating film 50 is also unnecessary.

[0054] (4) According to the above embodiment, the average particle size of the powder / particle material 53 is 100 nm or more. Therefore, a sufficient area can be secured as the boundary area between one powder / particle material 53 and the glass 52 in the mixed layer 51. Therefore, a situation in which the average particle size of the powder / particle material 53 is too small and the internal stress cannot be sufficiently divided at the boundary between the powder / particle material 53 and the glass 52 does not easily occur.

[0055] (5) The first thickness T1 corresponds to the thickness of the mixed layer 51. The second thickness T2 corresponds to the thickness of the glass layer 56. That is, according to the above embodiment, the thickness of the mixed layer 51 is greater than the thickness of the glass layer 56. Since the ratio of the mixed layer 51 in the insulating film 50 is thus considerably large, the insulating film 50 becomes less likely to peel off from the outer surface 21 of the element body 20.

[0056] (6) According to the above embodiment, the insulating film 50 has a crack 58. The crack 58 opens on the surface of the glass layer 56 opposite to the mixed layer 51. The internal stress of the insulating film 50 is combined so as to avoid the internal space of the crack 58. Therefore, compared to the case where the crack 58 does not exist, the internal stress of the insulating film 50 is less likely to be combined. In addition, when a new crack occurs due to an external impact, the existing crack 58 prevents the crack from progressing. Therefore, a large crack that may cause peeling of the insulating film 50 is unlikely to occur. Note that the crack 58 does not reach the element body 20. Therefore, the crack 58 itself is unlikely to cause peeling of the insulating film 50.

[0057] (7) According to the above embodiment, the material of the element body 20 is ceramics. The mixed layer 51 covers the outer surface 21 of the element body 20 without any other layers. As a result, when the mixed layer 51 is viewed from a direction perpendicular to the outer surface 21, the powder-granular material 53 is likely to be located so as to cover the grain boundaries between the particles of the element body 20. Therefore, even if a new crack develops in the insulating film 50 due to an impact applied from the outside of the insulating film 50, the powder-granular material 53 can prevent the new crack from developing to the grain boundaries of the element body 20. If the new crack can be prevented from developing to the grain boundaries of the element body 20, the new crack in the insulating film 50 can be prevented from developing along the grain boundaries of the element body 20.

[0058] <Other embodiments> The above embodiment can be modified as follows: The above embodiment and the following modifications can be combined and implemented within a range that does not cause technical contradiction.

[0059] In the above embodiment, the electronic component 10 is not limited to a negative characteristic thermistor component. For example, the electronic component 10 may be a thermistor component other than a negative characteristic thermistor component, a multilayer capacitor component, or an inductor component.

[0060] The material of the element body 20 is not limited to the examples in the above embodiments. For example, 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 column shape other than a quadrangular column shape having a central axis CA. The element body 20 may also be a core of a wound-type 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 on each end of the winding core portion.

[0061] The outer surface 21 of the element body 20 does not have to have a corner surface 24 including a curved surface. For example, if the boundary between adjacent flat surfaces 22 on the outer surface 21 of the element body 20 is not chamfered, there is no curved surface at that boundary. Therefore, at the location where three such boundaries intersect, there may not be a corner surface 24 including a curved surface.

[0062] The powder particles 53 may originate not only from the ceramic sheets that constituted the laminate, but also from the abrasive used to polish the laminate. In the example shown in FIG. 11, the element 20 has a minute recess 26. The inner surface of the recess 26 is recessed inward relative to the outer surface 21 of the element 20. The recess 26 is formed by ceramic particles falling off the element 20 in the R-chamfering process S12, and remains in the element 20 when polishing is not sufficient thereafter. In the example shown in FIG. 11, abrasive particles 53B of the abrasive used in the R-chamfering process S12 are present in the inner space of the recess 26. A part of one abrasive particle 53B is fixed so as to be stuck into the element 20. In this case, the abrasive particle 53B remaining in the inner space of the recess 26 functions as the powder particles 53. Examples of the material of the abrasive particle 53B include alumina and zirconia.

[0063] In the example shown in FIG. 11, when viewed from a direction perpendicular to the outer surface 21, the opening of the recess 26 in the outer surface 21 is smaller than the maximum range of the internal space. Therefore, element body-derived particles 53A, which are part of the element body 20 polished in the R chamfering process S12, are present in the internal space of the recess 26 as powder particles 53. In this way, when the element body 20 has the recess 26, it is easy for a large number of element body-derived particles 53A to be present in the internal space of the recess 26. This is therefore suitable for facilitating the formation of the mixed layer 51. Note that the shape of the recess 26 shown in FIG. 11 is simplified, and recesses 26 of various shapes can be formed in the element body 20.

[0064] In the example shown in FIG. 11, the abrasive particles 53B may be fixed so as to pierce the base body 20, or the abrasive particles 53B may be attached to the surface of the base body 20 by electrostatic attraction, or both may be present.

[0065] In the above embodiment, the material of the powder 53 does not have to be the same as that of the element 20 and the abrasive. For example, the powder 53 may be mixed in advance with the coating liquid. -6 15×10 or more -6 ( / K) or less is fine.

[0066] In the above embodiment, the powder / granules 53 may have an average particle size of 100 nm or less. In this case, the powder / granules 53 may be aggregated or dispersed. The smaller the average particle size of the powder / granules 53, the more likely the powder / granules 53 will aggregate with each other.

[0067] In the above embodiment, the first internal electrode 41 and the second internal electrode 42 may have any shape as long as they can ensure electrical conduction with the corresponding first external electrode 61 and second external electrode 62. Furthermore, the number of first internal electrodes 41 and second internal electrodes 42 does not matter, and the number of first internal electrodes 41 may be one, or three or more.

[0068] 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, and the first metal layer 61B may not have a two-layer structure. If the first external electrode 61 includes the first metal layer 61B, the insulating film 50 covers the entire outer surface 21 of the element body 20, thereby obtaining an effect of suppressing dissolution of the element body 20 in the plating solution. The same applies to the second external electrode 62.

[0069] In the above embodiment, the combination of materials of the first internal electrode 41 and the first base electrode 61A is not limited to the combination of palladium and silver. For example, it may be a combination of copper and nickel, copper and silver, silver and gold, nickel and cobalt, or nickel and gold. For example, it may be a combination of silver on one side and silver and palladium on the other side. For example, it may be a combination of palladium on one side and silver and palladium on the other side, or it may be a combination of copper on one side and silver and palladium on the other side. For example, it may be a combination of gold on one side and silver and palladium on the other side.

[0070] Depending on the combination of the first internal electrode 41 and the first base electrode 61A, the Kirkendall effect may not be obtained. In this case, before the external electrode forming step, for example, the first end face 22A side of the element body 20 may be polished to physically remove a part of the insulating film 50 so that the first internal electrode 41 is exposed. Then, the base electrode forming step may be performed to connect the first internal electrode 41 and the first base electrode 61A. Also, for example, after forming the first base electrode 61A, the insulating film 50 may be formed including the surface of the first base electrode 61A, and the insulating film 50 covering the surface of the first base electrode 61A may be removed. This point is also the same for the combination of materials of the second internal electrode 42 and the second base electrode 62A.

[0071] 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.

[0072] Regarding the insulating film 50, the glass layer 56 may contain powder and granular material 53. At least, the content of the powder and granular material 53 in the glass layer 56 needs to be smaller than the content of the powder and granular material 53 in the mixed layer 51.

[0073] First thickness T1 may be equal to or less than second thickness T2. It is sufficient that insulating film 50 has mixed layer 51 and glass layer 56. The boundary between mixed layer 51 and glass layer 56 does not need to be clear, and insulating film 50 can be said to have mixed layer 51 and glass layer 56 as long as the content of powder-and-granule material 53 is greater in the portion of insulating film 50 on the element body 20 side than in the portion of insulating film 50 on the surface side.

[0074] The position of the crack 58 in the insulating film 50 is not limited to the example in the above embodiment. Also, the crack 58 may be omitted in the insulating film 50. Furthermore, the number of cracks 58 may be multiple.

[0075] The insulating film 50 does not have to cover the entire area of ​​the outer surface 21 of the element body 20. In other words, part of the outer surface 21 of the element body 20 may be exposed from the insulating film 50. The area covered by the insulating film 50 may be changed as appropriate in accordance with the shape of the element body 20, the positions of the first external electrode 61 and the second external electrode 62, etc.

[0076] In the portion of the insulating film 50 that is covered with the first base electrode 61A, the glass 52 in the insulating film 50 may diffuse into the glass in the first base electrode 61A, so that the two become integrated.

[0077] The mixed layer 51 does not have to directly cover the outer surface 21 of the element body 20. For example, another layer may be interposed between the mixed layer 51 and the outer surface 21. Even in this case, as long as the mixed layer 51 is located on the element body 20 side as viewed from the glass layer 56, peeling of the insulating film 50 from the other layers can be suppressed. As a result, peeling of the insulating film 50 from the outer surface 21 of the element body 20 can be suppressed.

[0078] The material of the insulating film 50 is not limited to the example of the above embodiment. For example, the glass 52 and the glass 57 are not limited to silicon dioxide, and 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. The glass 52 and the glass 57 may be a multi-component oxide containing an alkali metal and Si, such as an Al-Si-based, Na-Si-based, K-Si-based, or Li-Si-based oxide. The glass 52 and the glass 57 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. The glass 52 and the glass 57 may not contain Si, and may be a mixture of these.

[0079] The material of the insulating film 50 may contain, in addition to the glass 52 and the glass 57, 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.

[0080] More specifically, in addition to glass 52, glass 57, and powder / granular material 53, insulating film 50 may contain additives such as organic acid salts, oxides, inorganic salts, organic salts, and other fine particles and nanoparticles of metal oxides.

[0081] 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.

[0082] An example of the oxide is sodium peroxide, and an example of the hydroxide is sodium hydroxide. 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.

[0083] Examples of inorganic salts include calcium peroxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium hydride, calcium carbide, and calcium phosphide.

[0084] 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. Examples of the additive include calcium acetate, calcium gluconate, calcium citrate, calcium malate, calcium lactate, calcium benzoate, calcium stearate, and calcium aspartate.

[0085] 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.

[0086] Also for example, the additive may be boron triiodide, sodium cyanoborohydride, sodium borohydride, tetrafluoroboric acid, triethylborane, borax, or boric acid.

[0087] For example, the additives include potassium arsenide, potassium bromide, potassium carbide, 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, potassium hydrogen fluoride, and tetramercury iodide ( II) acid, 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, potassium ethoxide toxoxide, 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, potassium hypomanganate The salt may be potassium phosphate, 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 hydrogen carbonate, potassium dihydrogen phosphate, dipotassium hydrogen phosphate, potassium hydrogen selenate, potassium hydrogen sulfite, potassium hydrogen sulfate, or potassium hydrogen peroxosulfate.

[0088] 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.

[0089] The additive may also be fine particles or nanoparticles of a metal oxide, such as sodium oxide, calcium oxide, lithium oxide, boron oxide, potassium oxide, barium oxide, silicon oxide, titanium oxide, zirconium oxide, aluminum oxide, zinc oxide, and magnesium oxide.

[0090] In the manufacturing method of the electronic component 10 of the above embodiment, the metal alkoxide 85 is not limited to the example of the above embodiment. Examples of elements from which the metal alkoxide 85 can be synthesized include Li, Be, B, C, Na, Mg, Al, Si, P, K, Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, As, Rb, Sr, Y, Zr, Nb, Mo, Cd, In, Sn, Sb, Cs, Ba, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Hf, Ta, W, Hg, Tl, Pb, Bi, Th, Pa, U, and Pu. Alkoxides of these elements can be used as glass precursors.

[0091] 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-benzenediolato-O,O')dipotassium silicate, ol Tetrabutyl tosilicate, aluminum silicate, calcium silicate, tetramethylammonium silicate solution, titanium(IV) chlorotriisopropoxide, 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.

[0092] In the manufacturing method of the electronic component 10 of the above embodiment, a metal complex or acetate, which is a precursor of the metal alkoxide 85, may be used instead of the metal alkoxide 85. In this case, in the metal alkoxide introduction step S17, a metal complex or acetate, which is a precursor of the metal alkoxide, may be introduced. Examples of the metal complex 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 the acetate include zirconium acetate, zirconium (IV) hydroxide acetate, and basic aluminum acetate.

[0093] In the manufacturing method of the electronic component 10, the external electrode forming step is not limited to the example of the above embodiment. For example, after the film forming step S18, the insulating film 50 may be cured by a heat treatment, and then the conductor applying step S20 and the curing step S21 may be performed to form the first external electrode 61 and the second external electrode 62. Also, for example, when a part of the first internal electrode 41 is exposed from the insulating film 50 as in the above-mentioned modified example, the first external electrode 61 may be formed on the exposed part by a plating method.

[0094] The curing step S21 is not limited to a step of simultaneously curing the insulating 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 curing step for curing the insulating film 50, and ultraviolet light may be irradiated as a step for curing the conductive paste.

[0095] In the above-described method for manufacturing electronic component 10, insulating film 50 may be hardened by sufficiently vaporizing water and polymer 84 in drying step S19. In this case, drying step S19 functions as a hardening step for hardening insulating film 50.

[0096] In the above-described method for manufacturing electronic component 10, the order of solvent introduction step S13, catalyst introduction step S14, and element introduction step S15 does not matter as long as metal alkoxide 85 and the catalyst start to react in reaction vessel 81 with solvent 82, element 20, and polymer 84 introduced into reaction vessel 81.

[0097] In the manufacturing method of the electronic component 10, the polymer 84 is not limited to polyvinylpyrrolidone. For example, the polymer 84 may be a homopolymer or copolymer of acrylic acid, methacrylic acid, or their esters, which are acrylic-based. Examples of the acrylic-based polymer include acrylic acid ester copolymers, methacrylic acid ester copolymers, and acrylic acid ester-methacrylic acid ester copolymers. Examples of the polymer 84 include homopolymers or copolymers of cellulose-based polymers, polyvinyl alcohol-based polymers, polyvinyl acetate-based polymers, polyvinyl chloride-based polymers, and polypropylene carbonate-based polymers. Examples of the cellulose-based polymers include hydroxypropyl cellulose, cellulose ether, carboxymethyl cellulose, acetyl cellulose, and acetyl nitro cellulose. Furthermore, the polymer 84 may include a plurality of types, and may include at least one type selected from the above examples.

[0098] In the above-described method for manufacturing electronic component 10, solvent 82 is not limited to 2-propanol. Solvent 82 may be changed as appropriate as long as it can disperse metal alkoxide 85 sufficiently.

[0099] The film formation method described in JP 2020-36002 A includes a solvent introduction step, a catalyst introduction step, an element introduction step, and a metal alkoxide introduction step. The film formation method also includes a film formation step. In the film formation step, an insulating film made of silicon oxide is formed on the outer surface of the element by hydrolysis and polycondensation reaction of the metal alkoxide.

[0100] In the film formation method described in JP 2020-36002 A, the size of silicon oxide may become excessively large during the film formation process. If large silicon oxide particles are present on the surface of the insulating film, when an impact from outside the element body 20 is applied to the vicinity of the particle, the particle may peel off the nearby insulating film 50 from the outer surface 21 of the element body 20.

[0101] According to the film formation method in the manufacturing method of electronic component 10 of the above embodiment, polymer 84 is introduced in polymer introduction step S16. In the film formation process of insulating film 50, polymer 84 is adsorbed onto outer surface 21 of element body 20. Then, glass particles derived from metal alkoxide 85 are incorporated into polymer 84 in metal alkoxide introduction step S17. Then, coarse glass particles that have grown excessively large cannot be incorporated into polymer 84. As a result, insulating film 50 does not contain excessively large particles.

[0102] Thus, from the viewpoint of reducing the excessive growth of coarse glass particles, the mixed layer 51 is not essential in the insulating film 50. That is, the insulating film 50 may be composed of glass 57 alone, for example.

[0103] Furthermore, by controlling the concentration of the metal alkoxide 85, the alkali concentration, the reaction temperature, the reaction time, the type of the solvent 82, the surface charge of the element body 20, and the like, the size of the coarse glass particles can be made smaller.

[0104] The technical ideas that can be understood from the above-described embodiment and modified examples are described below. <Appendix 1> A method for forming an insulating film containing a metal oxide on an outer surface of an element body, comprising the steps of: an element introduction step of introducing the element into a reaction vessel; a polymer introduction step of introducing a polymer that is to be adsorbed on the outer surface of the element body into the reaction vessel; a metal alkoxide introduction step of introducing a metal alkoxide or a metal alkoxide precursor into the container; a catalyst introduction step of introducing a catalyst for promoting hydrolysis of the metal alkoxide into the reaction vessel; and a film-forming step of forming the insulating film on the outer surface of the element body by hydrolysis and dehydration condensation of the metal alkoxide. Film formation method. [Explanation of symbols]

[0105] 10. Electronic components 20…Base 21...Outer surface 41...First internal electrode 42…Second internal electrode 50...Insulating film 51…Mixed layer 52...Glass 53…Powder material 56…Glass layer 57…Glass 58…Crack 61...First external electrode 62…Second external electrode 71…First penetration 72…Second penetration 81...Reaction vessel 82...Solvent 83...Aqueous solution 84…Polymer 85...Metal alkoxide

Claims

1. The semiconductor device comprises an element body and an insulating film covering an outer surface of the element body, the insulating film has a mixed layer containing glass and powder / granules, and a glass layer containing glass and having a smaller content of the powder / granules than the mixed layer; The mixed layer is located on the element body side as viewed from the glass layer. Electronic components.

2. Further, an external electrode is laminated on the insulating film, The external electrodes include a metal layer. The electronic component according to claim 1 .

3. The material of the powder is the same as that of the element. The electronic component according to claim 1 or 2.

4. The average particle size of the powder is 100 nm or more. The electronic component according to any one of claims 1 to 3.

5. In a cross-sectional view perpendicular to an outer surface of the body, When the powder or granule that is the furthest from the outer surface of the element body is defined as a specific powder or granule, the shortest distance from the outer surface of the element body to a specific point of the specific powder or grain that is the furthest from the outer surface of the element body is greater than the shortest distance from the specific point to the surface of the glass layer; The electronic component according to any one of claims 1 to 4.

6. The insulating film has a crack that opens on a surface of the glass layer opposite to the mixed layer and does not reach the element body. The electronic component according to any one of claims 1 to 5.

7. The material of the element is ceramics, The mixed layer covers the outer surface of the element body without any other layer therebetween. The electronic component according to any one of claims 1 to 6.

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