Electronic Components

Abstract

Provided is an electronic component in which a thick-film portion (52) is prevented from detaching from a film body (51). An insulating film (50) covers an outer surface (21) of an element body (20). The insulating film (50) comprises a film body (51) and a plurality of thick-film portions (52). The material of the film body (51) includes glass. The material of the thick-film portion (52) is the same as the glass of the film body (51). The thickness of the insulating film (50) where the thick-film portion (52) is present is greater than an average thickness of the film body (51).

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, an insulating film covering the outer surface of the element body, and ceramic particles distributed on the surface of the insulating film. The insulating film is made of glass. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5267511 Summary of the Invention [Problem to be solved by the invention]

[0004] In electronic components such as those described in Patent Document 1, some of the ceramic particles protrude from the surface of the insulating film. Therefore, depending on the amount of protrusion of the ceramic particles from the outer surface of the insulating film and the size of the contact area between the ceramic particles and the insulating film, the ceramic particles may fall off the insulating film. At the location where the ceramic particles have fallen off, a dent is generated in the insulating film. When such a dent is generated, there is a risk that a crack will occur in the insulating film starting from the dent. [Means for solving the problem]

[0005] In order to solve the above 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 film body and a plurality of thick film portions embedded in the film body, the material of the film body including glass, the material of the thick film portions being the same as the glass of the film body, and the thickness of the insulating film at the locations where the thick film portions are present being greater than the average thickness of the film body.

[0006] According to the above-mentioned configuration, since the thick film portion and the film body are made of the same material, there is no clear boundary between them, which makes it possible to prevent the thick film portion from falling off the film body. Effect of the Invention

[0007] The thick film portion can be prevented from falling off from the film body. [Brief description of the drawings]

[0008] [Figure 1] FIG. [Diagram 2] FIG. [Diagram 3] FIG. [Figure 4] 4 is a cross-sectional view taken along line 4-4 in FIG. 3. [Diagram 5] 5 is a cross-sectional view taken along line 5-5 in FIG. 3. [Figure 6] FIG. [Figure 7] FIG. [Figure 8] FIG. [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] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 12] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 13] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 14] 5A to 5C are explanatory diagrams illustrating a manufacturing method of an electronic component. [Figure 15] 1A to 1C are explanatory diagrams illustrating a film formation process for electronic components. [Figure 16] 1A to 1C are explanatory diagrams illustrating a film formation process for electronic components. [Figure 17] 1A to 1C are explanatory diagrams illustrating a film formation process for electronic components. [Figure 18] 1A to 1C are explanatory diagrams illustrating a film formation process for electronic components. [Figure 19]1A to 1C are explanatory diagrams illustrating a film formation process for electronic components. [Figure 20] 11 is a table showing the results of comparing electronic components of an embodiment and a comparative example. [Figure 21] FIG. 11 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 for ease of understanding. The dimensional ratios of the components may differ from those in the actual drawings or from those in other drawings.

[0010] (Overall composition) 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 faces 22. Hereinafter, when distinguishing between the six faces 22, they will be referred to as a first face 22A, a second face 22B, a third face 22C, a fourth face 22D, a fifth face 22E, and a sixth face 22F.

[0013] The first surface 22A is a plane perpendicular to the third axis Z. The first surface 22A faces the third positive direction Z1. Therefore, the first surface 22A extends in the directions along the first axis X and the second axis Y. That is, the first surface 22A extends parallel to the first axis X.

[0014] The second surface 22B is a plane perpendicular to the second axis Y. The second surface 22B faces the second positive direction Y1. Therefore, the second surface 22B spreads in the direction along the first axis X and the third axis Z. That is, the second surface 22B extends parallel to the first axis X. The angle between the second surface 22B and the first surface 22A on the element body 20 side is 90 degrees.

[0015] As shown in FIG. 2, the third surface 22C is a plane perpendicular to the third axis Z. The third surface 22C faces the third negative direction Z2. Therefore, the third surface 22C extends in the direction along the first axis X and the second axis Y. The third surface 22C is parallel to the first surface 22A. That is, the third surface 22C extends parallel to the first axis X. The angle between the third surface 22C and the second surface 22B on the element body 20 side is 90 degrees.

[0016] The fourth surface 22D is a plane perpendicular to the second axis Y. The fourth surface 22D faces the second negative direction Y2. Therefore, the fourth surface 22D spreads in the direction along the first axis X and the third axis Z. The fourth surface 22D is parallel to the second surface 22B. That is, the fourth surface 22D extends parallel to the first axis X. The angle between the fourth surface 22D and the third surface 22C on the element body 20 side is 90 degrees. The angle between the first surface 22A and the fourth surface 22D on the element body 20 side is 90 degrees.

[0017] 1, the fifth surface 22E is a plane perpendicular to the first axis X. The fifth surface 22E faces the first positive direction X1. Therefore, the fifth surface 22E extends in the directions along the second axis Y and the third axis Z. Among the angles formed by the fifth surface 22E and each of the first surface 22A to the fourth surface 22D, the angles on the element body 20 side are all 90 degrees.

[0018] 2, the sixth surface 22F is a plane perpendicular to the first axis X. The sixth surface 22F faces the first negative direction X2. Therefore, the sixth surface 22F extends in the directions along the second axis Y and the third axis Z. Among the angles formed by the sixth surface 22F and each of the first surface 22A to the fourth surface 22D, the angles on the element body 20 side are all 90 degrees.

[0019] 1, the outer surface 21 of the element body 20 has 12 boundary surfaces 23. The boundary surfaces 23 include curved surfaces that exist at the boundaries between adjacent 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 surfaces 22.

[0020] Hereinafter, when distinguishing between the twelve boundary surfaces 23, they will be referred to as a first boundary surface 23A, a second boundary surface 23B, . . . , a twelfth boundary surface 23L. The first boundary surface 23A is a boundary portion between the first surface 22A and the second surface 22B. Therefore, the first surface 22A and the second surface 22B are adjacent to each other via the first boundary surface 23A. The first boundary surface 23A extends parallel to the first axis X. The first boundary surface 23A has a curved portion in a cross-sectional view perpendicular to the first axis X. The curved portion extends in an arc equidistant from a specific point.

[0021] As shown in Fig. 2, the second boundary surface 23B is a boundary portion between the third surface 22C and the fourth surface 22D. Therefore, the third surface 22C and the fourth surface 22D are adjacent to each other via the second boundary surface 23B. The second boundary surface 23B extends parallel to the first axis X. The second boundary surface 23B has a curved portion in a cross-sectional view perpendicular to the first axis X. The curved portion extends in an arc equidistant from a specific point.

[0022] The third boundary surface 23C is a boundary portion between the first surface 22A and the fourth surface 22D. Therefore, the first surface 22A and the fourth surface 22D are adjacent to each other via the third boundary surface 23C. The third boundary surface 23C extends parallel to the first axis X. The third boundary surface 23C has a curved portion in a cross-sectional view perpendicular to the first axis X. The curved portion extends in an arc equidistant from a specific point.

[0023] 1, the fourth boundary surface 23D is a boundary portion between the second surface 22B and the third surface 22C. Therefore, the second surface 22B and the third surface 22C are adjacent to each other via the fourth boundary surface 23D. The fourth boundary surface 23D extends parallel to the first axis X. The fourth boundary surface 23D has a curved portion in a cross-sectional view perpendicular to the first axis X. The curved portion extends in an arc equidistant from a specific point.

[0024] The fifth boundary surface 23E is a boundary portion between the first surface 22A and the fifth surface 22E. Therefore, the first surface 22A and the fifth surface 22E are adjacent to each other via the fifth boundary surface 23E. The fifth boundary surface 23E extends parallel to the second axis Y. The fifth boundary surface 23E has a curved portion in a cross-sectional view perpendicular to the second axis Y. The curved portion extends in an arc equidistant from a specific point.

[0025] The sixth boundary surface 23F is a boundary portion between the second surface 22B and the fifth surface 22E. Therefore, the second surface 22B and the fifth surface 22E are adjacent to each other via the sixth boundary surface 23F. The sixth boundary surface 23F extends parallel to the third axis Z. The sixth boundary surface 23F has a curved portion in a cross section perpendicular to the third axis Z. The curved portion extends in an arc equidistant from a specific point.

[0026] The seventh boundary surface 23G is a boundary portion between the third surface 22C and the fifth surface 22E. Therefore, the third surface 22C and the fifth surface 22E are adjacent to each other via the seventh boundary surface 23G. The seventh boundary surface 23G extends parallel to the second axis Y. The seventh boundary surface 23G has a curved portion in a cross-sectional view perpendicular to the second axis Y. The curved portion extends in an arc equidistant from a specific point.

[0027] The eighth boundary surface 23H is a boundary portion between the fourth surface 22D and the fifth surface 22E. Therefore, the fourth surface 22D and the fifth surface 22E are adjacent to each other via the eighth boundary surface 23H. The eighth boundary surface 23H extends parallel to the third axis Z. The eighth boundary surface 23H has a curved portion in a cross section perpendicular to the third axis Z. The curved portion extends in an arc equidistant from a specific point.

[0028] 2, the ninth boundary surface 23I is a boundary portion between the first surface 22A and the sixth surface 22F. Therefore, the first surface 22A and the sixth surface 22F are adjacent to each other via the ninth boundary surface 23I. The ninth boundary surface 23I extends parallel to the second axis Y. The ninth boundary surface 23I has a curved portion in a cross-sectional view perpendicular to the second axis Y. The curved portion extends in an arc equidistant from a specific point.

[0029] The tenth boundary surface 23J is a boundary portion between the second surface 22B and the sixth surface 22F. Therefore, the second surface 22B and the sixth surface 22F are adjacent to each other via the tenth boundary surface 23J. The tenth boundary surface 23J extends parallel to the third axis Z. The tenth boundary surface 23J has a curved portion in a cross-sectional view perpendicular to the third axis Z. The curved portion extends in an arc equidistant from a specific point.

[0030] The eleventh boundary surface 23K is a boundary portion between the third surface 22C and the sixth surface 22F. Therefore, the third surface 22C and the sixth surface 22F are adjacent to each other via the eleventh boundary surface 23K. The eleventh boundary surface 23K extends parallel to the second axis Y. The eleventh boundary surface 23K has a curved portion in a cross-sectional view perpendicular to the second axis Y. The curved portion extends in an arc equidistant from a specific point.

[0031] The twelfth boundary surface 23L is a boundary portion between the fourth surface 22D and the sixth surface 22F. Therefore, the fourth surface 22D and the sixth surface 22F are adjacent to each other via the twelfth boundary surface 23L. The twelfth boundary surface 23L also extends along the third axis Z. The twelfth boundary surface 23L has a curved portion in a cross-sectional view perpendicular to the third axis Z. The curved portion extends in an arc equidistant from a specific point.

[0032] 1, 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 surfaces 22. In other words, the corner surfaces 24 include curved surfaces at the intersections of three boundary surfaces 23. The corner surfaces 24 include curved surfaces formed, for example, by R-chamfering the corners formed by the three adjacent surfaces 22.

[0033] Hereinafter, when distinguishing between the eight corner surfaces 24, they will be referred to as a first corner surface 24A, a second corner surface 24B, . . . , an eighth corner surface 24H. The first corner surface 24A is a boundary portion between the first surface 22A, the second surface 22B, and the fifth surface 22E. The first corner surface 24A is also a surface at the location where the first boundary surface 23A, the fifth boundary surface 23E, and the sixth boundary surface 23F intersect.

[0034] The second corner surface 24B is a boundary portion between the third surface 22C, the fourth surface 22D, and the fifth surface 22E. The second corner surface 24B is also a surface at the intersection of the second boundary surface 23B, the seventh boundary surface 23G, and the eighth boundary surface 23H.

[0035] The third corner surface 24C is a boundary portion between the first surface 22A, the fourth surface 22D, and the fifth surface 22E. The third corner surface 24C is also a surface at the location where the third boundary surface 23C, the fifth boundary surface 23E, and the eighth boundary surface 23H intersect.

[0036] The fourth corner surface 24D is a boundary portion between the second surface 22B, the third surface 22C, and the fifth surface 22E. The fourth corner surface 24D is also a surface at the intersection of the fourth boundary surface 23D, the sixth boundary surface 23F, and the seventh boundary surface 23G.

[0037] 2, the fifth corner surface 24E is a boundary portion between the first surface 22A, the second surface 22B, and the sixth surface 22F. The fifth corner surface 24E is also a surface at the intersection of the first boundary surface 23A, the ninth boundary surface 23I, and the tenth boundary surface 23J.

[0038] The sixth corner surface 24F is a boundary portion between the third surface 22C, the fourth surface 22D, and the sixth surface 22F. The sixth corner surface 24F is also a surface at the location where the second boundary surface 23B, the eleventh boundary surface 23K, and the twelfth boundary surface 23L intersect.

[0039] The seventh corner surface 24G is a boundary portion between the first surface 22A, the fourth surface 22D, and the sixth surface 22F. The seventh corner surface 24G is also a surface at the intersection of the third boundary surface 23C, the ninth boundary surface 23I, and the twelfth boundary surface 23L.

[0040] The eighth corner surface 24H is a boundary portion between the second surface 22B, the third surface 22C, and the sixth surface 22F. The eighth corner surface 24H is also a surface at the intersection of the fourth boundary surface 23D, the tenth boundary surface 23J, and the eleventh boundary surface 23K.

[0041] 1 to 3, 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 numeral. As shown in Fig. 3, the element body 20 has a larger dimension along the first axis X than the dimension 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 the dimension along the second axis Y.

[0042] The material of the element 20 is ceramics obtained by sintering a metal oxide containing at least one of Mn, Fe, Ni, Co, Ti, Ba, Al, and Zn. 4, 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.

[0043] 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.

[0044] 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.

[0045] 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. 5, 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.

[0046] 4, 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 second surface 22B in the second negative direction Y2. In this embodiment, the distances between the internal electrodes in the direction along the second axis Y are equal.

[0047] As shown in Fig. 5, 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. 4, the first internal electrodes 41 are biased toward the first positive direction X1, and the second internal electrodes 42 are biased toward the first negative direction X2.

[0048] 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.

[0049] 4, 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.

[0050] 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 fifth face 22E. Specifically, the first base electrode 61A is a five-sided electrode that covers the fifth face 22E of the element body 20 and portions of the first faces 22A to fourth faces 22D on the first positive direction X1 side. In this embodiment, the first base electrode 61A is made of silver and glass.

[0051] 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.

[0052] 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 sixth face 22F. Specifically, the second base electrode 62A is a five-sided electrode that covers the sixth face 22F of the element body 20 and portions of the first negative direction X2 sides of the first faces 22A to fourth faces 22D. 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.

[0053] 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.

[0054] The second external electrode 62 does not reach the first external electrode 61 on the first surface 22A to the fourth surface 22D, and is disposed apart from the first external electrode 61 in the direction along the first axis X. In addition, in the central portion in the direction along the first axis X on the first surface 22A to the fourth surface 22D of the element body 20, 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 4, the first external electrode 61 and the second external electrode 62 are illustrated by two-dot chain lines.

[0055] 4, 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.

[0056] 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. 4 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.

[0057] (Insulating film) Next, the insulating film 50 will be described in detail. 6, the insulating film 50 has a film body 51 and a plurality of thick film portions 52. The thickness of the film body 51 is approximately uniform. The material of the film body 51 is glass. In this embodiment, the insulating film 50 contains silicon dioxide as the glass.

[0058] The thick film portion 52 is embedded in the film body 51. The material of the thick film portion 52 is the same as the glass of the film body 51. The thick film portion 52 and the film body 51 are integrated, and there is no clear boundary between them.

[0059] In the following description, it is assumed that thick film portion 52 is not laminated on film body 51. In other words, when insulating film 50 is viewed in a direction perpendicular to outer surface 21 of element body 20, all the locations where thick film portion 52 exists are composed of thick film portion 52. And, when insulating film 50 is viewed in a direction perpendicular to outer surface 21 of element body 20, all the locations where film body 51 exists are composed of film body 51.

[0060] A part of each thick film portion 52 protrudes from the film body 51 toward the opposite side to the element body 20. That is, the thickness of the insulating film 50 at the location where the thick film portion 52 exists is greater than the average thickness of the film body 51. In this embodiment, the thick film portion 52 is dome-shaped overall.

[0061] The average thickness of the film body 51 is 30 nm or more and 1000 nm or less. The average thickness of the film body 51 is calculated by measuring the thickness at 10 points in an area where the thick film portion 52 does not exist and averaging these values. Note that the thickness of the film body 51 being approximately uniform means that the thickness of the film body 51 at each point is 10% or less of the average thickness of the film body 51. In other words, the portion of the insulating film 50 that is 10% or more thicker than the average thickness of the film body 51 is not the film body 51 but the thick film portion 52.

[0062] The average thickness of the film body 51 is preferably 0.15 to 0.91 times the average value of the maximum thicknesses TM of the thick film portions 52. The maximum thickness TM of the thick film portions 52 is the thickness dimension of the thickest portion of one of the thick film portions 52 in a cross-sectional view. The average value of the maximum thicknesses TM is a value calculated by measuring the maximum thicknesses TM of 10 thick film portions 52 and averaging the 10 maximum thicknesses TM.

[0063] Moreover, the maximum width WM of the thick membrane portion 52 is 0.7 to 4.0 times the maximum thickness TM of the thick membrane portion 52. The maximum width WM of the thick membrane portion 52 is the largest width dimension of the portion of the thick membrane portion 52 protruding from the membrane body 51 when the dimension of the thick membrane portion 52 in a direction parallel to the outer surface 21 of the element body 20 in a cross-sectional view is taken as the width dimension.

[0064] In addition, the maximum thickness TM of at least some of the thick membrane parts 52 is preferably less than 6.5 times the average thickness of the membrane body. Furthermore, it is further preferable that the maximum thickness TM of all the thick membrane parts 52 is less than 6.5 times the average thickness of the membrane body.

[0065] (Insulating film thickness at the boundary surface) Next, a method for calculating the first average dimension AD1 will be described. The first average dimension AD1 is the thickness of the insulating film 50 covering the first boundary surface 23A. In other words, the first average dimension AD1 is the average value of the distance from the first boundary surface 23A to the surface of the insulating film 50 covering the first boundary surface 23A in a direction perpendicular to the tangent of the first boundary surface 23A.

[0066] 5, first, a cross section CS that includes the center of the element body 20 in the direction along the first axis X and is perpendicular to the first axis X is photographed with an electron microscope. Then, as shown in Fig. 7, in order to calculate the first average dimension AD1, first, a first length L1, which is the length of the first boundary surface 23A, is measured in the cross section CS.

[0067] In measuring the first length L1, first, a first circle C1 including the curved portion of the first boundary surface 23A is drawn on the cross section CS. In this case, a part of the first circle C1 coincides with the curved portion of the first boundary surface 23A. Next, a first intersection P1 is determined where a straight line SL1 extending along the first surface 22A and a straight line SL2 extending along the second surface 22B intersect on the cross section CS. Next, a straight line SL3 is drawn connecting the center point P2 of the first circle C1 and the first intersection P1. Next, a second intersection P3 is determined where the straight line SL3 intersects with the first circle C1.

[0068] Next, draw the second circle C2 inscribed in the first circle C1. The second circle C2 is drawn so that the first circle C1 is tangent at the second intersection point P3. At this time, the center of the second circle C2 is on the straight line SL3. Furthermore, the diameter of the second circle C2 is twice the diameter of the first circle C1.

[0069] Next, a third intersection P4 where the second circle C2 and the first surface 22A intersect is determined. A fourth intersection P5 where the second circle C2 and the second surface 22B intersect is determined. Then, the length of the portion of the cross section CS that extends along the outer surface 21 of the element body 20 from the third intersection P4 to the fourth intersection P5 is defined as a first length L1, which is the length of the first boundary surface 23A.

[0070] Next, a fifth intersection P6 is defined where a straight line SL4 extending from the third intersection P4 in the third positive direction Z1 intersects with the surface of the insulating film 50 in the cross section CS. Also, a sixth intersection P7 is defined where a straight line SL5 extending from the fourth intersection P5 in the second positive direction Y1 intersects with the surface of the insulating film 50.

[0071] Next, a cross-sectional area S1 of a first range AR1 defined by a line from the third intersection point P4 to the fourth intersection point P5 along the outer surface 21, a straight line SL4, a straight line SL5, and a line from the fifth intersection point P6 to the sixth intersection point P7 along the surface of the insulating film 50 in the cross section CS is calculated by image processing. Then, a first average dimension AD1 is calculated by dividing the cross-sectional area S1 by the first length L1.

[0072] (Insulating film thickness on a flat surface) A method for calculating the second average dimension AD2 will be described. The second average dimension AD2 is the thickness of the insulating film 50 covering the first surface 22A. In other words, the second average dimension AD2 is the average value of the distance from the first surface 22A to the surface of the insulating film 50 covering the first surface 22A in a direction perpendicular to the first surface 22A. The second average dimension AD2 is measured at the cross section CS, similar to the first average dimension AD1.

[0073] 6, first, a center point P8 is defined as the center of the first surface 22A in the direction along the second axis Y in the cross section CS. Next, a point located along the outer surface 21 of the element body 20 and shifted from the center point P8 in the second positive direction Y1 by half the first length L1 is defined as a start point P9. Also, a point located along the outer surface 21 of the element body 20 and shifted in the second negative direction Y2 by half the first length L1 from the center point P8 is defined as an end point P10.

[0074] Next, a seventh intersection P11 is defined where a straight line SL6 extending in the third positive direction Z1 passing through the starting point P9 intersects with the surface of the insulating film 50. Also, an eighth intersection P12 is defined where a straight line SL7 extending in the third positive direction Z1 from the ending point P10 intersects with the surface of the insulating film 50.

[0075] Next, in the cross section CS, a cross-sectional area S2 of a second range AR2 defined by a line from the start point P9 to the end point P10 along the outer surface 21, a straight line SL6, a straight line SL7, and a line from the seventh intersection point P11 to the eighth intersection point P12 along the surface of the insulating film 50 is calculated by image processing. Then, the second average dimension AD2 is calculated by dividing the cross-sectional area S2 by the first length L1.

[0076] The first average dimension AD1 and the second average dimension AD2 are measured at a total of three locations on another cross section parallel to the cross section CS. The average thickness of the insulating film 50 covering the first surface 22A is calculated as the average value of the three first average dimensions AD1. The average thickness of the insulating film 50 covering the first boundary surface 23A is calculated as the average value of the three second average dimensions AD2. In this case, the average thickness of the insulating film 50 covering the first boundary surface 23A is larger than the average thickness of the insulating film 50 covering the first surface 22A.

[0077] (Thick film part at boundary surface) However, the first boundary surface 23A has more thick film portions 52 than the first surface 22A. Therefore, as shown in FIG. 8, in a cross section perpendicular to the first boundary surface 23A and parallel to the first axis X, a plurality of thick film portions 52 are present on the first boundary surface 23A. In the cross section, the plurality of thick film portions 52 are arranged along the first axis X. Therefore, in such a cross section perpendicular to the first boundary surface 23A and parallel to the first axis X, the first boundary surface 23A is highly likely to include the thick film portions 52. Therefore, as described above, the average thickness of the insulating film 50 covering the first boundary surface 23A is greater than the average thickness of the insulating film 50 covering the first surface 22A.

[0078] Moreover, for the second surface 22B to the fourth surface 22D, the average dimension calculated in the same manner as the second average dimension AD2 is substantially the same as the second average dimension AD2. Furthermore, for the second boundary surface 23B to the fourth boundary surface 23D, the average dimension calculated in the same manner as the first average dimension AD1 is substantially the same as the first average dimension AD1. Therefore, the average value of each of the average dimensions of the second boundary surface 23B to the fourth boundary surface 23D in different cross sections CS is larger than the average value of each of the average dimensions of the second surface 22B to the fourth surface 22D, similar to the first average dimension AD1.

[0079] Furthermore, for the fifth and sixth surfaces 22E and 22F, the average dimensions calculated in the same manner as the second average dimension AD2 are substantially the same as the second average dimension AD2. Furthermore, for the fifth to twelfth boundary surfaces 23E to 23L, the average dimensions calculated in the same manner as the first average dimension AD1 are substantially the same as the first average dimension AD1.

[0080] Here, as described above, the first corner surface 24A is a surface at the intersection of the first boundary surface 23A, the fifth boundary surface 23E, and the sixth boundary surface 23F. The average dimensions of the insulating film 50 at each of the first boundary surface 23A, the fifth boundary surface 23E, and the sixth boundary surface 23F are all larger than the second average dimension AD2. Therefore, the thickness of the insulating film 50 covering the first corner surface 24A is larger than the second average dimension AD2. Furthermore, the thickness of the insulating film 50 covering the first corner surface 24A is larger than the first average dimension AD1. Moreover, for the second corner surface 24B to the eighth corner surface 24H, the average value of the thickness dimension from each corner surface to the surface of the insulating film 50 is larger than the second average dimension AD2 and also larger than the first average dimension AD1.

[0081] <One embodiment of a method for manufacturing an electronic component> (Overall structure) Next, a method for manufacturing the electronic component 10 will be described.

[0082] 9, the method for manufacturing 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 manufacturing 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.

[0083] First, in forming the element body 20, in the laminate preparation step S11, a laminate is prepared as the element body 20 having no boundary surface 23 and no corner surface 24. That is, the laminate is in a state before R-chamfering and has a rectangular parallelepiped shape having six faces 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 laminated 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.

[0084] 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.

[0085] Next, a solvent introduction step S13 is performed. As shown in Fig. 10, 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. 9. As shown in Fig. 11, 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.

[0086] Next, an element body introducing step S15 is performed as shown in Fig. 9. As shown in Fig. 12, in the element body introducing step S15, a plurality of element bodies 20 formed in advance in the R chamfering step S12 as described above are introduced into a reaction vessel 81.

[0087] Next, a polymer introduction step S16 is performed as shown in Fig. 9. As shown in Fig. 13, in the polymer introduction step S16, polyvinylpyrrolidone is introduced as a polymer 84 into a reaction vessel 81. As a result, the polymer 84 introduced into the reaction vessel 81 is adsorbed onto the outer surface 21 of the element body 20. The molecular weight of polyvinypyrrolidone in this embodiment is 45,000.

[0088] Next, as shown in Fig. 9, a metal alkoxide introduction step S17 is performed. As shown in Fig. 14, 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.

[0089] 9, 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. The stirring time in the film-forming step S18 in this embodiment is 90 minutes.

[0090] In the film forming step S18, the insulating film 50 is formed by a liquid phase reaction in the reaction vessel 81. In this liquid phase reaction, the metal alkoxide 85 and the like contained in the solvent 82 are reacted in the liquid phase to form the insulating film 50.

[0091] 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. In this embodiment, the film-forming method for forming the insulating film 50 on the element body 20 includes 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.

[0092] 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 fifth surface 22E of the element body 20, and a portion including a portion covering the sixth surface 22F of the element body 20. Specifically, the conductor paste is applied so as to cover the insulating film 50 on the entire fifth surface 22E and parts of the first surface 22A to the fourth surface 22D. The conductor paste is also applied so as to cover the insulating film 50 on the entire sixth surface 22F and parts of the first surface 22A to the fourth surface 22D.

[0093] 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.

[0094] 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.

[0095] 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.

[0096] (Considerations regarding the film formation process) The inventors have discovered that in the above-mentioned film formation step S18, the film body 51 and the thick film portion 52 in the insulating film 50 are formed. Therefore, the formation of the film body 51 and the thick film portion 52 in the film formation process is considered along a time series. In the following, the sol-like insulating film 50 will be described as a glass layer 85C.

[0097] As shown in FIG. 15, when a polymer 84 is introduced into a reaction vessel 81 in a polymer introduction step S16, the polymer 84 is adsorbed to the outer surface 21 of the element body 20. As a result, a polymer layer 84L made of the polymer 84 is formed on the outer surface 21 of the element body 20. Since the polymer 84 is in a net shape, most of the polymer layer 84L is void. Then, the metal alkoxide 85 introduced in the metal alkoxide introduction step S17 is hydrolyzed by hydroxide ions serving as a catalyst. When the metal alkoxide 85 is hydrolyzed, the hydrolyzed metal alkoxides 85 undergo dehydration condensation with each other to form glass core particles 85A. A part of the formed glass core particles 85A slips through the steric hindrance of the polymer 84 in the polymer layer 84L and is adsorbed to the outer surface 21 of the element body 20.

[0098] 16, glass core particles 85A adsorbed on outer surface 21 of element body 20 undergo repeated hydrolysis and dehydration condensation to form a layered glass layer 85C covering outer surface 21. Furthermore, on glass layer 85C, hydrolyzed metal alkoxides 85 undergo dehydration condensation with each other to grow glass layer 85C.

[0099] On the other hand, hydrolyzed metal alkoxide 85 adheres to the surface of glass core particle 85A in solvent 82. Then, dehydration condensation of hydrolyzed metal alkoxide 85 proceeds on the surface of glass core particle 85A, and glass core particle 85A grows. As a result, glass core particle 85A in solvent 82 becomes large-sized glass nanoparticle 85B. A part of glass nanoparticle 85B is adsorbed to glass layer 85C.

[0100] As shown in FIG. 17, the glass nanoparticles 85B adsorbed on the glass layer 85C are integrated with the glass layer 85C by repeating hydrolysis and dehydration condensation. At this time, the glass nanoparticles 85B fall onto the surface of the glass layer 85C and spread as if melting on the surface of the glass layer 85C. Therefore, the glass layer 85C gradually grows to a uniform thickness. In addition, on the glass layer 85C, the hydrolyzed metal alkoxides 85 dehydrate and condense with each other, and the glass layer 85C further grows.

[0101] Meanwhile, glass nanoparticles 85B in solvent 82 gradually grow larger, similar to when glass core particles 85A grow into glass nanoparticles 85B. Some of the larger glass nanoparticles 85B are adsorbed to glass layer 85C.

[0102] 18, glass nanoparticles 85B adsorbed to glass layer 85C are integrated with glass layer 85C in the same manner as described above. Also, some of glass nanoparticles 85B in solvent 82 are adsorbed to glass layer 85C.

[0103] 19, the growth of glass layer 85C and the integration of glass nanoparticles 85B on glass layer 85C into glass layer 85C continue. When glass nanoparticles 85B in solvent 82 are no longer incorporated into polymer layer 84L, the growth in thickness of glass layer 85C stops.

[0104] Thereafter, in a curing step S21, glass layer 85C becomes insulating film 50 and polymer 84 is burned off. Therefore, insulating film 50 of manufactured electronic component 10 contains almost no polymer 84. In glass layer 85C, some glass nanoparticles 85B protrude outward beyond the other portion that becomes film main body 51, thereby forming thick film portion 52 of insulating film 50.

[0105] In this manner, glass layer 85C grows such that glass nanoparticles 85B are integrated with and become part of glass layer 85C, so that in insulating film 50, no boundary exists between film body 51 and thick film portion 52.

[0106] Furthermore, a portion of the glass nanoparticles 85B that is not completely formed into a layer is formed as part of the thick film portion 52. As a result, the thick film portion 52 is formed to protrude outward beyond the film body 51.

[0107] Furthermore, glass layer 85C grows to have a uniform thickness in a layered manner, so that the thickness of glass layer 85C is generally uniform except for the portions resulting from glass nanoparticles 85B that are attached toward the end of film-forming step S18.

[0108] (Results of the comparative test) Here, electronic component 10 manufactured by the above-mentioned manufacturing method is referred to as Example 1. In electronic component 10 of Example 2, the molecular weight of polyvinylpyrrolidone used as polymer 84 is 1.2 million, as compared with Example 1. Other conditions are the same as those of Example 1.

[0109] Unlike Example 1, electronic component 10 of Example 3 did not use polymer 84 and was produced by omitting polymer dosing step S16. Unlike Example 1, electronic component 10 of Example 4 uses polyvinylpyrrolidone as polymer 84 having a molecular weight of 2.8 million.

[0110] The electronic component 10 of Example 5 was manufactured by repeating the film formation method of Example 2 four times. The electronic component 10 of Example 6 was manufactured by repeating the film formation method of Example 4 five times. The electronic component 10 of Example 7 was manufactured by repeating the film formation method of Example 4 ten times.

[0111] The electronic component of the comparative example was manufactured by mixing nanoparticles made of at least one of titanium oxide and zirconium oxide having an average particle size of 450 nm, unlike Example 1. Note that electronic components 10 of Examples 1 to 7 and the electronic component of the comparative example were manufactured using the same amount of metal alkoxide 85.

[0112] The average thickness of film body 51 of insulating film 50 was measured for electronic components 10 of Examples 1 to 7 and the electronic component of the comparative example. The average thickness of film body 51 was measured at cross section CS passing through the center in the direction along first axis X of element body 20. In addition, the maximum thickness TM and maximum width WM of thick film portion 52 were measured for electronic components 10 of Examples 1 to 7 and the electronic component of the comparative example.

[0113] Furthermore, the maximum width WM relative to the maximum thickness TM was calculated from the measured maximum thickness TM and maximum width WM of the thick membrane portion 52. Also, the average thickness of the membrane body 51 relative to the maximum thickness TM of the thick membrane portion 52 was calculated from the measured average thickness of the membrane body 51 and the maximum thickness TM of the thick membrane portion 52.

[0114] The electronic components 10 of Examples 1 to 7 and the electronic component of the comparative example were evaluated by micro-scratch and chipping tests. The micro-scratch test was performed by scanning a diamond needle with a tip radius of curvature of 25 μm for 400 μm under a load of 100 mN. If no scratches were observed, the component was deemed to have passed, and if scratches were observed, the component was deemed to have failed. The chipping test was performed by oscillating 1000 electronic components under a predetermined load. If 10 or more chips were observed, the component was deemed to have failed, and if less than 10 chips were observed, the component was deemed to have passed. In FIG. 20, ◯ indicates a pass, and × indicates a fail.

[0115] 20, the electronic components of Examples 1 to 7 passed both the micro-scratch and chipping tests, whereas the electronic component of Comparative Example failed both the micro-scratch and chipping tests.

[0116] (Operation of the embodiment) (1) In the above embodiment, the thickness of the insulating film 50 at the location where the thick film portion 52 exists is greater than the average thickness of the film body 51. The thick film portion 52 and the film body 51 are made of the same material and are integrated with each other, with no clear boundary between them. Therefore, the thick film portion 52 is firmly connected to the film body 51, and thus it is possible to prevent the thick film portion 52 from falling off the film body 51.

[0117] (2) In the above embodiment, the first base electrode 61A of the first external electrode 61 covers the surface of the insulating film 50. The thickness of the insulating film 50 at the location where the thick film portion 52 exists is greater than the average thickness of the film body 51. Therefore, compared to the case where the thick film portion 52 does not exist, it is easier to obtain a larger contact area with the first base electrode 61A by the amount that the thick film portion 52 protrudes outward from the film body 51. As a result, the first base electrode 61A and the insulating film 50 can be bonded more firmly.

[0118] (3) In the above embodiment, the average thickness of the film body 51 is 30 nm or more. Therefore, even if an impact is applied from outside the electronic component 10, the film body 51 has a considerable thickness and is therefore likely to withstand the impact. Also, in the above embodiment, the average thickness of the film body 51 is 1000 nm or less. In this manner, when the average thickness of the film body 51 is considerably small, if ceramic particles are distributed in the insulating film 50, the ceramic particles tend to protrude significantly from the insulating film 50. Therefore, the ceramic particles tend to detach from the insulating film 50. This is therefore suitable for applying a configuration in which the thick film portion 52 and the film body 51 are integrated.

[0119] (4) In the above embodiment, the average thickness of the film body 51 is 0.15 times or more the average value of the maximum thickness TM of the thick film portion 52. Therefore, the film body 51 is considerably smaller than the thick film portion 52. Therefore, the thick film portion 52 protrudes significantly from the film body 51. Nevertheless, since the thick film portion 52 is integrated with the film body 51, the thick film portion 52 is unlikely to detach from the film body 51.

[0120] Moreover, the average thickness of the film body 51 is 0.91 times or less the average value of the maximum thickness TM of the thick film portion 52. Therefore, the thick film portion 52 does not excessively protrude from the film body 51. Therefore, when the thick film portion 52 is subjected to an impact from the outside due to the thick film portion 52 excessively protruding from the film body 51, it is possible to suppress the occurrence of damage such as chipping or cracking in the thick film portion 52.

[0121] (5) In the above embodiment, the maximum width WM of the thick membrane portion 52 is 0.7 times or more the maximum thickness TM of the thick membrane portion 52. Therefore, the contact area of ​​the thick membrane portion 52 with the element body 20 is considerably large. Therefore, the thick membrane portion 52 is more unlikely to detach from the element body 20.

[0122] Moreover, the maximum width WM of the thick film portion 52 is 4.0 times or less the maximum thickness TM of the thick film portion 52. Therefore, the thick film portion 52 extends considerably toward the outside. Therefore, the insulating film 50 is easily subjected to an external shock in a portion not covered by the first external electrode 61 and the second external electrode 62. Nevertheless, the thick film portion 52 is integrated with the film body 51, so that the thick film portion 52 is unlikely to detach from the film body 51. Furthermore, in a portion of the insulating film 50 covered by the first external electrode 61 and the second external electrode 62, the contact area of ​​the first external electrode 61 and the second external electrode 62 can be increased, so that the insulating film 50 and the first external electrode 61 and the second external electrode 62 can be firmly bonded to each other.

[0123] (6) In the above embodiment, the part of the insulating film 50 covering the first boundary surface 23A is more likely to collide with other objects such as a jig or other electronic components than the part of the insulating film 50 covering the first surface 22A. According to the above embodiment, the average thickness of the insulating film 50 covering the first boundary surface 23A on the surface of the insulating film 50 is greater than the average thickness of the insulating film 50 covering the first surface 22A. Therefore, the insulating film 50 has a greater protective effect on the first boundary surface 23A than on the first surface 22A. Therefore, even if the part of the outer surface 21 of the insulating film 50 covering the first boundary surface 23A collides with another object, the impact is less likely to reach the element body 20. As a result, damage to the first boundary surface 23A of the element body 20 can be suppressed.

[0124] <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.

[0125] In the above embodiment, the electronic component 10 is not limited to a negative characteristic thermistor component, but may be, for example, a thermistor component other than a negative characteristic thermistor component, a multilayer capacitor component, or an inductor component.

[0126] 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 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. In this case, the boundary surface 23 is a surface at a point where the angle formed by the adjacent surfaces 22 on the element body 20 side is less than 180 degrees.

[0127] 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 faces 22 of 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.

[0128] The outer surface 21 of the element body 20 does not have to have the first boundary surface 23A including a curved surface. For example, the element body 20 may be a laminated body that has not been subjected to the R chamfering process S12. In this case, the outer surface 21 is made up of the first surface 22A to the sixth surface 22F.

[0129] The range of the first boundary surface 23A in the above embodiment is merely an example. The first boundary surface 23A may be any range as long as it is defined as a region including all the curved parts of the boundary between the first surface 22A and the second surface 22B. That is, in the example shown in FIG. 7, the first length L1 may be a length that includes the curved parts of the boundary between the first surface 22A and the second surface 22B. In the example shown in FIG. 7, when the diameter of the second circle C2 is set to be the same as the diameter of the first circle C1, the first length L1 becomes a length that includes only the curved parts of the boundary between the first surface 22A and the second surface 22B. Also, in the above embodiment, the diameter of the second circle C2 can be changed as appropriate as long as it is equal to or greater than the diameter of the first circle C1. However, it is necessary to determine the diameter of the second circle C2 so that the first range AR1 and the second range AR2 do not overlap. This is also true for the other boundary surfaces 23. It should be noted that the smaller the first length L1, ie, the smaller the flat portion of the boundary surface 23, the greater the first average dimension AD1 tends to be than the second average dimension AD2.

[0130] 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.

[0131] 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.

[0132] 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.

[0133] 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 fifth surface 22E 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.

[0134] 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 fifth surface 22E and one of the first surface 22A to the fourth surface 22D. The same applies to the second external electrode 62.

[0135] 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.

[0136] In the portion of the insulating film 50 that is covered with the first base electrode 61A, the glass of the insulating film 50 may diffuse into the glass of the first base electrode 61A, and the two may become integrated.

[0137] The average thickness of the film body 51 is not limited to the example in the above embodiment. The average thickness of the film body 51 may be less than 30 nm or more than 1000 nm. The average thickness of the film body 51 may be less than 0.15 times the average value of the maximum thickness TM of the thick film portion 52, or may be greater than 0.91 times the average value of the maximum thickness TM of the thick film portion 52. If the average thickness of the film body 51 is 0.22 to 0.90 times the average value of the maximum thickness TM of the thick film portion 52, the evaluation results of the micro scratch and chipping test are passed. Therefore, it is more preferable that the average thickness of the film body 51 is within this range.

[0138] In the cross section CS, the maximum width WM of the thick membrane portion 52 may be less than 0.7 times the maximum thickness TM of the thick membrane portion 52, or may be greater than 4.0 times the maximum thickness TM of the thick membrane portion 52. The calculation method of the first average dimension AD1 in the above embodiment is an example and can be changed. For example, in the cross section CS, a plurality of points are randomly identified on the boundary surface 23. A tangent line is drawn at each of the identified points, and an orthogonal line perpendicular to the tangent line is drawn. The average value in the thickness direction on the orthogonal line from the boundary surface 23 to the surface of the insulating film 50 may be set as the first average dimension AD1. Similarly, the calculation method of the second average dimension AD2 can also be changed.

[0139] The average thickness of the insulating film 50 covering the first boundary surface 23A may be equal to or less than the average thickness of the insulating film 50 covering the first surface 22A. For example, the first surface 22A may also have a significantly larger number of thick film portions 52 overall, so that the average thickness of the insulating film 50 covering the first surface 22A may be greater than the average thickness of the insulating film 50 covering the first boundary surface 23A.

[0140] The shape of the thick film portion 52 is not limited to the example of the above embodiment. In the modified example shown in FIG. 21, the thick film portion 52 has a flat shape as a whole in the cross section CS. The shape of the thick film portion 52 is determined in the process of repeating hydrolysis and dehydration condensation of the glass nanoparticles 85B in the above-mentioned film formation process. If the film formation process S18 ends immediately after the glass nanoparticles 85B adhere to the glass layer 85C and are integrated, the outer side of the thick film portion 52 tends to be arc-shaped. On the other hand, when the film formation process S18 ends after a considerable time has elapsed in which the glass nanoparticles 85B adhere to the glass layer 85C and repeat hydrolysis and dehydration condensation, the thick film portion 52 may have a flat shape as a whole, as in the modified example shown in FIG. 21.

[0141] The material of the insulating film 50 is not limited to the example of the above embodiment. For example, the glass is not limited to silicon dioxide, and may be a multi-component oxide containing Si, such as B-Si, Si-Zn, Zr-Si, or Al-Si oxides. The glass may be a multi-component oxide containing an alkali metal and Si, such as Al-Si, Na-Si, K-Si, or Li-Si oxides. The glass may be a multi-component oxide containing an alkaline earth metal and Si, such as Mg-Si, Ca-Si, Ba-Si, or Sr-Si. The glass may not contain Si, and may be a mixture of these.

[0142] The material of the insulating film 50 may contain, in addition to glass, a surface treatment agent or an antistatic agent such as a pigment, a silicone-based flame retardant, a silane coupling agent, or a titanate coupling agent. That is, the material of the film body 51 and the material of the thick film portion 52 may contain at least glass.

[0143] More specifically, the insulating film 50 may contain, in addition to glass, additives such as organic acid salts, oxides, inorganic salts, organic salts, and other fine particles and nanoparticles of metal oxides. 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.

[0144] 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.

[0145] Examples of inorganic salts include calcium peroxide, calcium hydroxide, calcium fluoride, calcium chloride, calcium bromide, calcium iodide, calcium hydride, calcium carbide, and calcium phosphide.

[0146] 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.

[0147] 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.

[0148] Also for example, the additive may be boron triiodide, sodium cyanoborohydride, sodium borohydride, tetrafluoroboric acid, triethylborane, borax, or boric acid.

[0149] 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.

[0150] 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.

[0151] 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.

[0152] 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.

[0153] 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.

[0154] 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.

[0155] In the manufacturing method of the electronic component 10, the base electrode forming step is not limited to the example of the 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 base electrode 61A and the second base electrode 62A. 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] 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.

[0161] In the manufacturing method of the electronic component 10, the polymer injection step S16 may be omitted. The electronic component 10 of the above-mentioned Example 3 is formed by omitting the polymer injection step S16. Even if the electronic component 10 does not have the polymer 84, the film body 51 and the thick film portion 52 are formed integrally in the film formation process.

[0162] 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.

[0163] 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 is applied to the vicinity of the particle, the particle may peel off the nearby insulating film from the outer surface of the element body.

[0164] 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.

[0165] In this way, from the viewpoint of reducing the excessive growth of coarse glass particles, the thick film portion 52 is not essential. Moreover, the dimensional relationship between the thick film portion 52 and the film body 51 is not limited to the example of the above embodiment.

[0166] 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 20, and the like, the coarse particle size can be made smaller.

[0167] 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]

[0168] 10. Electronic components 20…Base 21...Outer surface 41...First internal electrode 42…Second internal electrode 50...Insulating film 51…Membrane body 52…Thick film section 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 film body and a plurality of thick film portions embedded in the film body, The material of the film body includes glass, The material of the thick film portion is the same as the glass of the film body, A part of the thick film portion protrudes from the film body toward the opposite side to the element body, and the thickness of the insulating film at the location where the thick film portion exists is greater than the average thickness of the film body. Electronic components.

2. The insulating film further includes an external electrode that covers the surface of the insulating film. The electronic component according to claim 1 .

3. The average thickness of the film body is 30 nm or more and 1000 nm or less. The electronic component according to claim 1 or 2.

4. The average thickness of the film body is 0.15 to 0.91 times the average value of the maximum thickness of the thick film portion. The electronic component according to any one of claims 1 to 3.

5. In a cross section perpendicular to the outer surface, The maximum width of the thick film portion is 0.7 to 4.0 times the maximum thickness of the thick film portion. The electronic component according to any one of claims 1 to 4.

6. The outer surface has a planar first surface, a second surface adjacent to the first surface and extending in a direction different from the first surface, and a boundary surface including a curved surface that exists at the boundary between the first surface and the second surface, an angle between the first surface and the second surface on the body side is less than 180 degrees; In a cross section perpendicular to the first surface and the second surface, the average thickness of the insulating film covering the boundary surface is greater than the average thickness of the insulating film covering the first surface. The electronic component according to any one of claims 1 to 5.

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