Electronic component

Abstract

The present invention provides an electronic component capable of reducing the risk of failure in the market. The electronic component has: a substrate including two end faces facing each other and a bottom face connecting between the two end faces; a coil disposed in the substrate; and an external electrode disposed on the substrate and electrically connected to the coil. On a first cross section intersecting the two end faces and the bottom face of the substrate, the external electrode has a first portion extending along one of the end faces and the bottom face of the substrate, and the first portion is buried in the substrate to be exposed from the first face. The coil is configured such that the outer periphery of the coil faces the first face of the substrate, and the shortest distance between the outer periphery of the coil and the first face of the substrate is smaller than the minimum width of the first portion in a direction orthogonal to the first face.

Description

[0001] This application is a divisional application of a patent application for an invention titled "Electronic Component" with an application number of 201710740855.1 and a filing date of August 25, 2017. Technical Field

[0002] The present invention relates to an electronic component. Background Art

[0003] Conventionally, as an electronic component, there is the content described in Japanese Patent Application Laid-Open No. 2014-39036 (Patent Document 1). This electronic component has a substrate including a bottom surface, a coil provided in the substrate, and an external electrode provided on the substrate and electrically connected to the coil. The external electrode is buried in the substrate to be exposed from the bottom surface of the substrate.

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2014-39036

[0005] In addition, when actually manufacturing and using an electronic component as described above in the past, the following problems have been found. First, from the viewpoint of manufacturing efficiency, such an electronic component includes: a mother laminate forming step of forming a plurality of matrix-shaped mother laminates of the parts that will become the electronic component; and a cutting step of singling the formed mother laminate into units of the electronic component. The external electrode of the electronic component is pre-formed by the mother laminate forming step, and by the cutting step, the required part is left on the substrate and made to be exposed from the bottom surface of the substrate. At this time, if a cutting deviation occurs in the cutting step, the external electrode is cut off, and the amount of the external electrode buried in the substrate decreases.

[0006] If the amount of the external electrode buried in the substrate decreases in this way, the contact area between the external electrode and the substrate decreases, and the adhesion force between the external electrode and the substrate decreases. Moreover, when the electronic component is mounted on the substrate and after mounting, if stress is applied to the electronic component, there is a possibility of peeling between the external electrode and the substrate. Therefore, the fixing strength of the electronic component to the substrate cannot be ensured, and the resistance of the electronic component to bending of the substrate cannot be ensured. In addition, even in a state where the adhesion force between the external electrode and the substrate is reduced in this way, since the external electrode is buried in the substrate, the shape of the external electrode exposed on the bottom surface of the substrate does not change, so it is also impossible to screen the electronic components in the state where the adhesion force is reduced based on the appearance. Therefore, since the problem occurs after mounting on the substrate and the electronic component is in the above state is clarified, the risk of failure in the market increases. Summary of the Invention

[0007] Therefore, an object of the present invention is to provide an electronic component capable of reducing the risk of failure in the market.

[0008] To solve the above problems, an electronic component according to one aspect of the present invention includes:

[0009] A base body, which includes two end faces facing each other and a bottom face connecting between the two end faces;

[0010] A coil, which is disposed in the base body; and

[0011] An external electrode, which is disposed on the base body and electrically connected to the coil,

[0012] On a first cross-section of the base body that intersects with the two end faces and the bottom face,

[0013] The external electrode has a first portion extending along one of the end face and the bottom face of the base body, and the first portion is buried in the base body to be exposed from the first face,

[0014] The coil is configured such that the outer periphery of the coil faces the first face of the base body,

[0015] The shortest distance between the outer periphery of the coil and the first face of the base body is smaller than the minimum width of the first portion in a direction orthogonal to the first face.

[0016] According to the above electronic component, the risk of failure in the market can be reduced.

[0017] In addition, in an embodiment of the electronic component,

[0018] On the first cross-section of the base body,

[0019] The external electrode has a second portion extending along the other of the end face and the bottom face of the base body, and the second portion is buried in the base body to be exposed from the second face,

[0020] The coil is configured such that the outer periphery of the coil faces the second face of the base body,

[0021] The shortest distance between the outer periphery of the coil and the second face of the base body is smaller than the minimum width of the second portion in a direction orthogonal to the second face.

[0022] According to the above embodiment, the risk of failure in the market can be further reduced.

[0023] In addition, in an embodiment of the electronic component,

[0024] On the first cross-section of the base body,

[0025] The minimum width a1 of the first portion and the overlapping width b2 between the coil and the first portion satisfy (1 / 3)×a1≤b2.

[0026] Here, the overlapping width b2 of the coil and the first part refers to the width in the direction orthogonal to the first surface of the overlapping part of the coil and the first part along the direction of the first surface.

[0027] According to the above-described embodiment, the acquisition efficiency of the L value and the Q value is further improved.

[0028] In addition, in one embodiment of the electronic component,

[0029] On the first cross-section of the above-described substrate,

[0030] The minimum width c1 of the above-described second part and the overlapping width d2 of the above-described coil and the above-described second part satisfy (1 / 3)×c1 ≤ d2.

[0031] Here, the overlapping width d2 of the coil and the second part refers to the width in the direction orthogonal to the second surface of the overlapping part of the coil and the second part along the direction of the second surface.

[0032] According to the above-described embodiment, the acquisition efficiency of the L value and the Q value is further improved.

[0033] In addition, in one embodiment of the electronic component,

[0034] On the first cross-section of the above-described substrate,

[0035] The minimum width a1 of the above-described first part and the shortest distance b1 between the outer periphery of the above-described coil and the first surface of the above-described substrate satisfy b1 < (2 / 3)×a1.

[0036] According to the above-described embodiment, the acquisition efficiency of the L value and the Q value is further improved.

[0037] In addition, in one embodiment of the electronic component,

[0038] On the first cross-section of the above-described substrate,

[0039] The minimum width c1 of the above-described second part and the shortest distance d1 between the outer periphery of the above-described coil and the second surface of the above-described substrate satisfy d1 < (2 / 3)×c1.

[0040] According to the above-described embodiment, the acquisition efficiency of the L value and the Q value is further improved.

[0041] In addition, in one embodiment of the electronic component,

[0042] On the first cross-section of the above-described substrate,

[0043] The overlapping width b2 of the above-described coil and the above-described first part satisfies b2 ≥ 3 μm.

[0044] According to the above-described embodiment, when the embedding amount of the first portion of the external electrode is reduced to around 3 μm, it can be distinguished by the appearance of the electronic component.

[0045] Further, in one embodiment of the electronic component,

[0046] On the first cross-section of the above-described substrate,

[0047] The overlapping width d2 of the above-described coil and the second portion satisfies d2 ≥ 3 μm.

[0048] According to the above-described embodiment, when the embedding amount of the second portion of the external electrode is reduced to around 3 μm, it can be distinguished by the appearance of the electronic component.

[0049] Further, in one embodiment of the electronic component, the axis of the above-described coil intersects the first cross-section of the above-described substrate.

[0050] According to the above-described embodiment, the proportion of the magnetic flux generated by the coil shielded by the first portion of the external electrode can be reduced.

[0051] Further, in one embodiment of the electronic component, the above-described substrate is composed of a plurality of insulating layers laminated in a direction intersecting the first cross-section of the above-described substrate, and the above-described coil includes a coil conductor layer wound around the insulating layer.

[0052] According to the above-described embodiment, miniaturization and low-profile of the electronic component are achieved.

[0053] Further, in one embodiment of the electronic component, the above-described coil has a structure in which a plurality of the above-described coil conductor layers laminated and electrically connected in series with each other and having less than one turn are stacked.

[0054] According to the above-described embodiment, the coil can be formed in a spiral shape.

[0055] Further, in one embodiment of the electronic component, the above-described external electrode includes two electrodes, a first external electrode and a second external electrode, which are respectively electrically connected to one end and the other end of the above-described coil. The first external electrode is exposed from one of the two end faces and the bottom face, and the second external electrode is exposed from the other of the two end faces and the bottom face.

[0056] According to the above-described embodiment, an electronic component having a bottom face exposing both of the two L-shaped external electrodes as a mounting surface can be formed.

[0057] Further, in one embodiment of the electronic component, the above-described external electrode has a structure in which a plurality of external electrode conductor layers embedded in the above-described substrate are stacked, and the external electrode conductor layer has a portion extending along the end face and the bottom face.

[0058] According to the above-described embodiment, miniaturization of the electronic component can be achieved.

[0059] The electronic component according to the present invention can reduce the risk of failure in the market. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 is a perspective three-dimensional view showing one embodiment of the electronic component.

[0061] Figure 2 is an exploded three-dimensional view of the electronic component.

[0062] Figure 3 is a cross-sectional view of the electronic component.

[0063] Figure 4A is a cross-sectional view showing a case where a cutting offset has occurred on the bottom surface side of the base.

[0064] Figure 4B is a bottom view showing a case where a cutting offset has occurred on the bottom surface side of the base.

[0065] Figure 5A is a cross-sectional view showing a case where a cutting offset has occurred on the first end face side of the base.

[0066] Figure 5B is an end view showing a case where a cutting offset has occurred on the first end face side of the base.

[0067] Figure 6 is an explanatory view for explaining other shapes of the external electrodes. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0068] Hereinafter, the electronic component as one aspect of the present invention will be described in detail with reference to the illustrated embodiments.

[0069] (Embodiment)

[0070] Figure 1 is a perspective three-dimensional view showing one embodiment of the electronic component. Figure 2 is an exploded three-dimensional view of the electronic component. Figure 3 is a cross-sectional view of the electronic component. As Figure 1 , Figure 2 and Figure 3 shown, the electronic component 1 has a base 10, a spiral coil 20 provided inside the base 10, a first external electrode 30 provided on the base 10 and electrically connected to the coil 20, and a second external electrode 40. In Figure 1 , in order to facilitate understanding of the structure, the base 10 is drawn as transparent, but it may also be translucent or opaque.

[0071] The electronic component 1 is electrically connected to the wirings of a circuit board (not shown) via first and second external electrodes 30 and 40. The electronic component 1 is used, for example, as a coil for impedance matching (matching coil) of a high-frequency circuit, and can be used in electronic devices such as personal computers, DVD players, digital cameras, TVs, mobile phones, automotive electronics, medical / industrial instruments, etc. However, the use of the electronic component 1 is not limited thereto. For example, it can also be used in tuning circuits, filter circuits, rectifying and smoothing circuits, etc.

[0072] The base body 10 is formed by laminating a plurality of insulating layers 11. The insulating layer 11 is made of, for example, a material mainly composed of borosilicate glass, ferrite, resin, or the like. In addition, there is a case where the interfaces between the plurality of insulating layers 11 become unclear due to firing or the like in the base body 10. The base body 10 is substantially formed in a rectangular parallelepiped shape. The surface of the base body 10 has a first end face 15, a second end face 16 located on the opposite side of the first end face 15, and a bottom face 17 connecting between the first end face 15 and the second end face 16. The first end face 15 and the second end face 16 face each other in a direction orthogonal to the lamination direction A of the insulating layers 11. Here, the so-called "orthogonal" in the present application is not limited to an exact orthogonal relationship, and includes a substantially orthogonal relationship in consideration of the range of actual deviations.

[0073] Figure 3 The cross-section of shows, as an example of the first cross-section of the present embodiment, the upper surface of the fourth insulating layer 11 counted from the top, and this cross-section is orthogonal to the first end face 15, the second end face 16, and the bottom face 17 of the base body 10. At this time, the plurality of insulating layers 11 are laminated in a direction orthogonal to this cross-section. Figure 2 The cross-section of shows, as an example of the first cross-section of the present embodiment, the upper surface of the fourth insulating layer 11 counted from the top, and this cross-section is orthogonal to the first end face 15, the second end face 16, and the bottom face 17 of the base body 10. At this time, the plurality of insulating layers 11 are laminated in a direction orthogonal to this cross-section.

[0074] The first external electrode 30 and the second external electrode 40 are made of, for example, a conductive material such as Ag, Cu, Au, or an alloy mainly composed of them. The first external electrode 30 is in an L shape extending across the first end face 15 and the bottom face 17. The second external electrode 40 is in an L shape extending across the second end face 16 and the bottom face 17.

[0075] In addition, the first external electrode 30 and the second external electrode 40 have a structure in which a plurality of external electrode conductor layers 33 and 34 are laminated and buried in the substrate 10. The external electrode conductor layer 33 has an L-shaped form having a portion extending along the first end face 15 and the bottom face 17, and the external electrode conductor layer 43 has an L-shaped form having a portion extending along the second end face 16 and the bottom face 17. Thus, since the external electrodes 30 and 40 can be buried in the substrate 10, miniaturization of the electronic component can be achieved as compared with a structure in which the external electrodes are disposed outside the substrate 10. In addition, the coil 20 and the external electrodes 30 and 40 can be formed by the same process, and by reducing the deviation in the positional relationship between the coil 20 and the external electrodes 30 and 40, the deviation in the electrical characteristics of the electronic component 1 can be reduced.

[0076] The coil 20 is made of, for example, the same conductive material as the first and second external electrodes 30 and 40. The coil 20 is wound in a spiral shape along the lamination direction A of the insulating layer 11. One end of the coil 20 is in contact with the first external electrode 30, and the other end of the coil 20 is in contact with the second external electrode 40. In addition, in the present embodiment, the coil 20 is integrated with the first and second external electrodes 30 and 40 and there is no clear boundary, but it is not limited thereto, and a boundary may exist by forming the coil and the external electrodes by different types of materials and different types of methods.

[0077] The axis of the coil 20 is orthogonal to the first cross section of the substrate 10. In addition, the axis of the coil 20 means the central axis of the spiral shape of the coil 20.

[0078] The coil 20 includes a plurality of coil conductor layers 21 wound around the insulating layer 11. In this way, by forming the coil 20 with the coil conductor layers 21 capable of performing microfabrication, miniaturization and low-profile of the electronic component 1 can be achieved. The coil conductor layers 21 adjacent to each other in the lamination direction A are electrically connected in series via via conductors penetrating the insulating layer 11 in the thickness direction. In this way, the plurality of coil conductor layers 21 are electrically connected to each other in series and form a spiral. Specifically, the coil 20 has a structure in which a plurality of coil conductor layers 21 that are electrically connected to each other in series and have less than one turn are laminated, and the coil 20 has a spiral shape. At this time, the parasitic capacitance generated in the coil conductor layer 21 and the parasitic capacitance generated between the coil conductor layers 21 can be reduced, and the Q value of the electronic component 1 can be improved.

[0079] As Figure 3As shown, on the first cross-section of the substrate 10, the first external electrode 30 has a first portion 31 extending along the bottom surface 17 of the substrate 10 and a second portion 32 extending along the first end surface 15 of the substrate 10. In the present embodiment, the bottom surface 17 is an example of the first surface, and the first end surface 15 is an example of the second surface. In addition, it can also be that the bottom surface 17 is an example of the first surface and the first end surface 15 is an example of the second surface.

[0080] The first portion 31 is buried in the substrate 10 to be exposed from the bottom surface 17. The exposed surface of the first portion 31 is in the same plane (the same horizontal plane) as the bottom surface 17. The second portion 32 is buried in the substrate 10 to be exposed from the first end surface 15. The exposed surface of the second portion 32 is in the same plane (the same horizontal plane) as the first end surface 15.

[0081] The second external electrode 40, similar to the first external electrode 30, has a first portion 41 extending along the bottom surface 17 (an example of the first surface) and a second portion 42 extending along the second end surface 16 (an example of the second surface). The first portion 41 of the second external electrode 40 has the same structure as the first portion 31 of the first external electrode 30. The second portion 42 of the second external electrode 40 has the same structure as the second portion 32 of the first external electrode 30. Here, the axis of the coil 20 intersects the first cross-section. This means that the axis of the coil 20 is parallel to the directions in which the first portions 31 and 41 of the first and second external electrodes 30 and 40 extend and the directions in which the second portions 32 and 42 extend. Thus, the magnetic flux of the coil 20 generated near the first and second external electrodes 30 and 40 is parallel to the first portions 31 and 41 and the second portions 32 and 42. Therefore, the proportion of the magnetic flux shielded by the first portions 31 and 41 and the second portions 32 and 42 can be reduced, and since the eddy current loss generated by the first and second external electrodes 30 and 40 is reduced, a decrease in the Q value of the coil 20 can be suppressed.

[0082] Hereinafter, based on Figure 3 the relationship between the first external electrode 30 and the coil 20 in the first cross-section will be described. For the relationship between the second external electrode 40 and the coil 20, it is the same by replacing an example of the second surface from the first end surface 15 with the second end surface 16.

[0083] The coil 20 is arranged such that the outer periphery 20a of the coil 20 faces the bottom surface 17 of the substrate 10 and the first and second end surfaces 15 and 16. The outer periphery 20a is formed in a semicircular shape. The shape of the outer periphery 20a is not limited to a semicircle and can also be a circle including an ellipse, an arc, a polygon, or a combination thereof. The outer periphery 20a is buried in the substrate 10 without being exposed from the bottom surface 17 and the first and second end surfaces 15 and 16. In addition, the so-called outer periphery 20a of the coil 20 refers to the outer periphery of the coil 20 when viewed from the axial direction of the coil 20.

[0084] The shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base 10 is smaller than the minimum width a1 of the first portion 31 in the direction orthogonal to the bottom surface 17.

[0085] The shortest distance d1 between the outer periphery 20a of the coil 20 and the first end face 15 of the base 10 is smaller than the minimum width c1 of the second portion 32 in the direction orthogonal to the first end face 15. Further, in the present embodiment, the line widths of the first portion 31 and the second portion 32 are constant (rectangular shape) up to the front end. When the front end face on the second end face 16 side of the first portion 31 and the front end face on the side opposite to the bottom surface 17 of the second portion 32 are curved or inclined with respect to the bottom surface 17 and the first end face 15, the minimum width of the portion excluding the front end face is set as the minimum width a1.

[0086] According to the above-described electronic component 1, on the first cross-section of the base 10, the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base 10 is smaller than the minimum width a1 of the first portion 31 of the first external electrode 30 in the direction orthogonal to the bottom surface 17 of the base 10.

[0087] Thus, for example, as Figure 4A shown, even if the cutting offset amount in the cutting process is such that the first portion 31 of the external electrode 30 is not cut at all (the exposed shape of the external electrode 30 on the bottom surface 17 does not change), if it exceeds a certain amount, the outer periphery 20a of the coil 20 is exposed on the bottom surface 17 of the base 10. Therefore, by appropriately setting the cutting offset amount at which the outer periphery 20a is exposed from the base 10, it is possible to screen, by the appearance of the bottom surface 17, the electronic component 1 in which the embedding amount is insufficient and the adhesion force between the external electrode 30 and the base 10 is reduced.

[0088] Thus, it is possible to screen and ship out the electronic component 1 in which the adhesion force between the first external electrode 30 and the base 10 is ensured. When the electronic component 1 is mounted on a substrate or after mounting, even if stress is applied to the electronic component 1, peeling between the first external electrode 30 and the base 10 can be suppressed. Therefore, the fixing strength of the electronic component 1 to the substrate can be ensured, and the resistance of the electronic component 1 to bending of the substrate can be ensured. In this way, according to the electronic component 1, the risk of failure in the market can be reduced.

[0089] In addition, regarding the appearance of the electronic component 1 in the above description, a method of screening by exposing the outer periphery 20a of the coil 20 on the bottom surface 17 of the base 10 is described. However, depending on the structure and material of the base 10, there are cases where it is possible to distinguish by appearance even when the outer periphery 20a is not exposed at all on the bottom surface 17. For example, when the base 10 has some light transmissivity, if the distance between the outer periphery 20a and the bottom surface 17 becomes sufficiently small, the outer periphery 20a can be seen through the bottom surface 17 of the base 10. Therefore, for example, during appearance screening, by appropriately setting the threshold for pass / fail determination in the image recognition device for the contrast between the outer periphery 20a appearing on the bottom surface 17 and other parts, it is possible to screen the electronic component 1 in which the embedding amount of the first external electrode 30 is insufficient. Therefore, in the electronic component 1, appearance screening can also be performed in the range where the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base 10 is greater than 0.

[0090] In addition, in the electronic component 1, compared with the case where the shortest distance b1 is equal to or greater than the minimum width a1, the outer periphery 20a of the coil 20 can be closer to the bottom surface 17 of the base 10. Therefore, the inner diameter of the coil 20 can be further increased without increasing the outer dimensions. In this way, by increasing the inner diameter of the coil 20, the acquisition efficiency of the L value and the Q value is improved.

[0091] According to the above-mentioned electronic component 1, on the first cross-section of the base 10, the shortest distance d1 between the outer periphery 20a of the coil 20 and the first end face 15 of the base 10 is smaller than the minimum width c1 of the second part 32 of the first external electrode 30 in the direction orthogonal to the first end face 15 of the base 10.

[0092] Thus, for example, as Figure 5A shown, even if the cutting offset amount in the cutting process is such that the second part 32 of the external electrode 30 is not cut at all (the exposed shape of the external electrode 30 on the first end face 15 does not change), if it exceeds a certain amount, the outer periphery 20a of the coil 20 is exposed on the first end face 15 of the base 10. Therefore, by appropriately setting the cutting offset amount at which the outer periphery 20a is exposed from the base 10, it is possible to screen the electronic component 1 in which the embedding amount is insufficient and the adhesion force between the external electrode 30 and the base 10 is reduced through the appearance of the first end face 15.

[0093] Thus, it is possible to screen and ship the electronic component 1 that ensures the adhesion force between the first external electrode 30 and the base 10. When the electronic component 1 is mounted on the substrate or after mounting, even if stress is applied to the electronic component 1, peeling between the first external electrode 30 and the base 10 can be suppressed. Therefore, the fixing strength of the electronic component 1 to the substrate can be ensured, and the resistance of the electronic component 1 to bending of the substrate can be ensured. In this way, according to the electronic component 1, the risk of failure in the market can be reduced.

[0094] In addition, in the electronic component 1, the shortest distance b1 is smaller than the minimum width a1, and the shortest distance d1 is smaller than the minimum width c1. Thus, in the electronic component 1, for any one of the cutting offsets in the direction orthogonal to the bottom surface 17 and the cutting offset in the direction orthogonal to the first end surface 15, since it is possible to screen by the appearance of the electronic component 1 when the adhesion force between the external electrode 30 and the base 10 decreases, the risk of failures in the market can be further reduced.

[0095] Furthermore, in the electronic component 1, compared with the case where the shortest distance d1 is equal to or greater than the minimum width c1, since the outer periphery 20a of the coil 20 can be brought closer to the first end surface 15 of the base 10, the inner diameter of the coil 20 can be further increased without increasing the outer dimensions. In this way, by increasing the inner diameter of the coil 20, the acquisition efficiency of the L value and the Q value is improved. In particular, in the electronic component 1, since the outer periphery 20a can be brought closer to both the bottom surface 17 and the first end surface 15 of the base 10, the acquisition efficiency of the L value and the Q value is further improved.

[0096] Preferably, on the first section of the base 10, the minimum width a1 of the first part 31 and the overlapping width b2 of the coil 20 and the first part 31 satisfy (1 / 3)×a1 ≤ b2. At this time, with respect to the embedding amount a1 of the base 10 in the direction orthogonal to the bottom surface 17 of the external electrode 30, the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base 10 is smaller than (2 / 3)×a1. Therefore, the inner diameter of the coil 20 can be further increased without increasing the outer dimensions, and the acquisition efficiency of the L value and the Q value is further improved.

[0097] Preferably, on the first section of the base 10, the minimum width c1 of the second part 32 and the overlapping width d2 of the coil 20 and the second part 32 satisfy (1 / 3)×c1 ≤ d2. At this time, with respect to the embedding amount c1 of the base 10 in the direction orthogonal to the first end surface 15 of the external electrode 30, the shortest distance d1 between the outer periphery 20a of the coil 20 and the first end surface 15 of the base 10 is smaller than (2 / 3)×c1. Therefore, the inner diameter of the coil 20 can be further increased without increasing the outer dimensions, and the acquisition efficiency of the L value and the Q value is further improved.

[0098] In addition, as Figure 3 shown, the overlapping width b2 of the coil 20 and the first part 31 is the width in the direction orthogonal to the bottom surface 17 within the range where the coil 20 and the first part 31 overlap (are arranged in the same straight line) in the direction parallel to the bottom surface 17 (the first surface) on the first section of the base 10. In addition, as Figure 3As shown, the overlapping width d2 between the coil 20 and the second portion 32 is the width in the direction orthogonal to the bottom surface 17 within the range where the coil 20 overlaps (is arranged in the same straight line) with the first portion 31 in the direction parallel to the first end surface 15 (second surface) on the first cross-section of the base body 10.

[0099] Preferably, on the first cross-section of the base body 10, the minimum width a1 of the first portion 31 and the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base body 10 satisfy b1 < (2 / 3) × a1. In this way, by making the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base body 10 smaller than a certain amount, the inner diameter of the coil 20 can be further increased without increasing the external dimensions, and the acquisition efficiency of the L value and Q value is further improved.

[0100] Preferably, on the first cross-section of the base body 10, the minimum width c1 of the second portion 32 and the shortest distance d1 between the outer periphery 20a of the coil 20 and the first end surface 15 of the base body 10 satisfy d1 < (2 / 3) × c1. In this way, by making the shortest distance d1 between the outer periphery 20a of the coil 20 and the first end surface 15 of the base body 10 smaller than a certain amount, the inner diameter of the coil 20 can be further increased without increasing the external dimensions, and the acquisition efficiency of the L value and Q value is further improved.

[0101] Preferably, on the first cross-section of the base body 10, the overlapping width b2 between the coil 20 and the first portion 31 in the direction along the bottom surface 17 satisfies b2 ≥ 3 μm. Thus, when the embedding amount of the first portion 31 of the first external electrode 30 is reduced to around 3 μm, it can be distinguished through the appearance of the electronic component 1.

[0102] Preferably, on the first cross-section of the base body 10, the overlapping width d2 between the coil 20 and the second portion 32 in the direction along the first end surface 15 satisfies d2 ≥ 3 μm. Thus, when the embedding amount of the second portion 32 of the first external electrode 30 is reduced to around 3 μm, it can be distinguished through the appearance of the electronic component 1. In addition, when the embedding amounts of the first portion 31 and the second portion 32 are less than 3 μm, there is a possibility of peeling between the first external electrode 30 and the base body 10.

[0103] Above, the effects based on the relationship between the first external electrode 30 and the coil 20 have been described, but the effects based on the relationship between the second external electrode 40 and the coil 20 are the same. In addition, in this embodiment, the relationship between the second external electrode 40 and the coil 20 is the same as the relationship between the first external electrode 30 and the coil 20, but this relationship can also be different. That is, at least one of the first external electrode 30 and the second external electrode 40 satisfies the above relationship with the coil 20.

[0104] In addition, the present invention is not limited to the above-described embodiments, and design changes can be made without departing from the gist of the present invention.

[0105] In the above-described embodiment, the external electrodes 30 and 40 have the first portions 31 and 41 and the second portions 32 and 42, but they may be side electrodes or bottom electrodes having only portions corresponding to the first portions 31 and 41 or portions corresponding to the second portions 32 and 42. Further, in the above-described embodiment, the structure is such that both the first portions 31 and 41 and the second portions 32 and 42 extend parallel to the coil axis, but as long as at least one of the first portion or the second portion extends parallel to the coil axis, eddy current loss can be reduced.

[0106] In the above-described embodiment, on the first cross-section of the base 10, the shortest distance b1 between the outer periphery 20a of the coil 20 and the bottom surface 17 of the base 10 is smaller than the minimum width a1 of the first portion 31, and the shortest distance d1 between the outer periphery 20a of the coil 20 and the first end surface 15 of the base 10 is smaller than the minimum width c1 of the second portion 32, but it is not necessarily limited to this structure. For example, it may be a structure that only satisfies either the shortest distance between the outer periphery of the coil and the bottom surface of the base is smaller than the minimum width of the first portion, or the shortest distance between the outer periphery of the coil and the first end surface of the base is smaller than the minimum width of the second portion.

[0107] Moreover, when the shortest distance between the outer periphery of the coil and the bottom surface of the base is smaller than the minimum width of the first portion, when the outer periphery of the coil is arranged to face the bottom surface of the base, the axis of the coil may also be orthogonal to the first end surface and the second end surface.

[0108] On the other hand, when the shortest distance between the outer periphery of the coil and the first end surface of the base is smaller than the minimum width of the second portion, when the outer periphery of the coil is arranged to face the first end surface of the base, the axis of the coil may also be orthogonal to the bottom surface. In addition, in the above-described embodiment, the axis of the coil 20 is orthogonal to the first cross-section, but it is sufficient that the axis of the coil intersects at least the first cross-section.

[0109] In addition, in the above-described embodiment, Figure 3 the cross-section is taken as an example of the first cross-section, but the first cross-section may also be another cross-section orthogonal to the first end surface, the second end surface, and the bottom surface. Specifically, the first cross-section may also be Figure 2 any one of the upper surfaces of the plurality of insulating layers 11 in which the coil conductor layer 21, the external electrode conductor layers 33 and 43 are arranged. In addition, in the above-described embodiment, in Figure 2The configuration satisfies the above relationship on the entire upper surface (first cross-section) of the plurality of insulating layers 11 including the coil conductor layer 21 and the external electrode conductor layers 33 and 43, but it may also satisfy the above relationship only on a part of the upper surface (first cross-section). Further, the first cross-section is not limited to a cross-section orthogonal to the first end face, the second end face, and the bottom face, and may also be a cross-section intersecting the first end face, the second end face, and the bottom face. In addition, the stacking direction A is not limited to a direction orthogonal to the first cross-section, and may also be a direction intersecting the first cross-section.

[0110] In the above-described embodiment, the coil 20 is formed by stacking the coil conductor layers 21, but it may also be formed by a wire such as a copper wire covered with insulation. Further, in the above-described embodiment, the coil 20 is a structure in which a plurality of coil conductor layers 21 with a stacking turn number of less than one turn are stacked, but the turn number of the coil conductor layer 21 may also be one turn or more. That is, the coil 20 may also be in a spiral shape.

[0111] In the above-described embodiment, the external electrodes 30 and 40 are two structures, i.e., the first external electrode 30 and the second external electrode 40, which are respectively connected to one end and the other end of the coil 20. The first external electrode 30 is exposed from the first end face 15 and the bottom face 17, and the second external electrode is exposed from the second end face 16 and the bottom face 17. Thus, both the first external electrode 30 and the second external electrode 40 can use the exposed bottom face 17 as a mounting face facing the substrate.

[0112] In the above-described embodiment, the external electrodes 30 and 40 are in an L shape composed of the first portions 31 and 41 and the second portions 32 and 42, but as Figure 6 shown in (a) to (n), it may also be a shape including a third portion. Further, in Figure 6 , the shape of the first external electrode is described, but the shape of the second external electrode may be the same as or different from that of the first external electrode. In addition, in Figure 6 , since the first portion 31 and the second portion 32 have the same structure as the first external electrode 30, the description is omitted or simplified.

[0113] As Figure 6 (a) shows, in addition to the L-shaped first portion 31 and second portion 32, the first external electrode 30A further has a third portion 35. The third portion 35 includes a concave curved surface connecting the front ends of the first portion 31 and the second portion 32.

[0114] As Figure 6 (b) shows, the third portion 35 of the first external electrode 30B is formed in a concave arc-shaped band shape connecting the front ends of the first portion 31 and the second portion 32. As Figure 6As shown in (c), the third portion 35 of the first external electrode 30C is formed in a linear strip shape connecting the front ends of the first portion 31 and the second portion 32.

[0115] As Figure 6 As shown in (d), the third portion 35 of the first external electrode 30D has an inclined surface connecting the front ends of the first portion 31 and the second portion 32, and a V-shaped notch is formed in the central portion of the inclined surface. As Figure 6 As shown in (e), the third portion 35 of the first external electrode 30E has a plurality of V-shaped notches formed in the inclined surface.

[0116] As Figure 6 As shown in (f), the third portion 35 of the first external electrode 30F is formed in a convex arc strip shape connecting the middle portions of the first portion 31 and the second portion 32. As Figure 6 As shown in (g), the third portion 35 of the first external electrode 30G protrudes from the connecting portion of the first portion 31 and the second portion 32 in a substantially quarter-circular shape. Figure 6 As shown in (h), the third portion 35 of the first external electrode 30H is formed in a convex arc strip shape connecting the middle portions of the first portion 31 and the second portion 32, and a circular portion is provided in the middle portion of the arc strip shape.

[0117] As Figure 6 As shown in (i), the third portion 35 of the first external electrode 30I protrudes from the connecting portion of the first portion 31 and the second portion 32 in a quadrilateral shape. As Figure 6 As shown in (j), the third portion 35 of the first external electrode 30J is formed in a stepped shape.

[0118] As Figure 6 As shown in (k), the third portion 35 of the first external electrode 30K is a shape formed by hollowing out the inside of the third portion 35 of the first external electrode 30I. As Figure 6 As shown in (l), the third portion 35 of the first external electrode 30L is a shape formed by hollowing out the inside of the third portion 35 of the first external electrode 30J multiple times.

[0119] As Figure 6 As shown in (m), the third portion 35 of the first external electrode 30M includes a circular portion protruding from the middle portion of the first portion 31 and a circular portion protruding from the middle portion of the second portion 32. As Figure 6 As shown in (n), the third portion 35 of the first external electrode 30N includes an extension portion extending along the angle bisector between the first portion 31 and the second portion 32 from the connecting portion of the first portion 31 and the second portion 32 and a semicircle connected to the front end of the extension portion.

[0120] Here, for example, asFigure 6 As shown in (a), in the external electrodes 30A to 30N, the minimum width a1 of the first part 31 and the minimum width c1 of the second part 32 are the widths at the front end portions of the first part 31 and the second part 32, respectively. In addition, in the first external electrodes 30A to 30N, the first part 31, the second part 32, and the third part 35 may all be discrete components with distinct boundaries, or the first part 31, the second part 32, and the third part 35 may be integrated without distinct boundaries.

[0121] (Embodiment)

[0122] Hereinafter, an embodiment of the manufacturing method of the electronic component 1 will be described.

[0123] First, an insulating paste mainly composed of borosilicate glass is repeatedly coated on a base material such as a carrier film by screen printing to form an insulating layer. This insulating layer is an outer insulating layer located outside the coil conductor layer. In addition, the base material is peeled off from the insulating layer through an arbitrary process and does not remain in the state of the electronic component.

[0124] After that, a photosensitive conductive paste layer is formed by coating on the insulating layer, and a coil conductor layer and an external electrode conductor layer are formed through a photolithography process. Specifically, a photosensitive conductive paste mainly composed of Ag is coated on the insulating layer by screen printing to form a photosensitive conductive paste layer. Further, the photosensitive conductive paste layer is irradiated with ultraviolet rays or the like through a photomask and developed with an alkaline solution or the like. Thereby, a coil conductor layer and an external electrode conductor layer are formed on the insulating layer. At this time, the coil conductor layer and the external electrode conductor layer can be drawn into a desired pattern through the photomask. At this time, the shortest distance between the outer periphery of the coil conductor layer (coil) and the position of the outer edge of the insulating layer is made smaller than the width of the external electrode conductor layer (external electrode).

[0125] Then, a photosensitive insulating paste layer is formed by coating on the insulating layer, and an insulating layer provided with openings and through holes is formed through a photolithography process. Specifically, a photosensitive insulating paste is coated on the insulating layer by screen printing to form a photosensitive insulating paste layer. Further, the photosensitive insulating paste layer is irradiated with ultraviolet rays or the like through a photomask and developed with an alkaline solution or the like. At this time, the photosensitive insulating paste layer is patterned through the photomask so as to provide an opening above the external electrode conductor layer and a through hole at the end of the coil conductor layer.

[0126] Thereafter, a photosensitive conductive paste layer is formed by coating on the insulating layer provided with openings and through holes, and a coil conductor layer and an electrode conductor layer are formed through a photolithography process. Specifically, a photosensitive conductive paste mainly composed of Ag is coated on the insulating layer by screen printing to fill the openings and through holes, thereby forming a photosensitive conductive paste layer. Further, ultraviolet rays or the like are irradiated on the photosensitive conductive paste layer through a photomask, and development is performed using an alkaline solution or the like. As a result, an external electrode conductor layer connected to the external electrode conductor layer on the lower layer side through the opening and a coil conductor layer connected to the coil conductor layer on the lower layer side through the through hole are formed on the insulating layer.

[0127] By repeatedly performing the processes of forming the insulating layer, the coil conductor layer, and the external electrode conductor layer as described above, a coil composed of a plurality of coil conductor layers formed on the insulating layer and an external electrode composed of a plurality of external electrode conductor layers formed on the insulating layer are formed. Further, an insulating paste is repeatedly coated on the insulating layer on which the coil and the external electrode are formed by screen printing to form an insulating layer. This insulating layer is an insulating layer for the outer layer located outside the coil conductor layer. In addition, if the combination of the coil and the external electrode is formed in a matrix shape in the above processes, a mother laminate can be obtained.

[0128] Thereafter, the mother laminate is cut into a plurality of unfired laminates by cutting or the like. In the cutting process of the mother laminate, the external electrode is exposed from the mother laminate on the cut surface formed by cutting. At this time, if the cutting offset exceeds a certain amount, the outer periphery of the coil conductor layer formed by the above process appears on the end face or the bottom face.

[0129] Then, the unfired laminate is fired under specified conditions to obtain a substrate including the coil and the external electrode. The substrate is subjected to grinding to be ground into an appropriate outer dimension, and a Ni plating layer with a thickness of 2 μm to 10 μm and a Sn plating layer with a thickness of 2 μm to 10 μm are applied to the portion where the external electrode is exposed from the laminate. Through the above processes, an electronic component of 0.4 mm × 0.2 mm × 0.2 mm is completed.

[0130] Furthermore, thereafter, an appearance inspection of the electronic component is performed to screen out the electronic components in which the outer periphery of the coil conductor layer is exposed or visible on the end face or the bottom face. At this time, for each design value of the minimum width of the first part / second part of the external electrode of the electronic component and the shortest distance between the outer periphery and the end face / bottom face of the substrate, the overlapping width between the coil and the first part / second part, the screening threshold value during the appearance inspection, etc. are appropriately set. As a result, it is possible to screen out the electronic components in which the adhesion force between the external electrode and the substrate is reduced. Therefore, the risk of failure in the market can be reduced.

[0131] In addition, the method for forming the electronic component is not limited to the above. For example, the method for forming the coil conductor layer and the external electrode conductor layer may also be a printing and laminating method of a conductor paste based on a screen plate with an opening in the shape of a conductor pattern, or a method of forming a pattern on a conductor film formed by sputtering, evaporation, crimping of a foil, etc. through etching or a metal mask. It may also be a method such as the semi-additive method in which after forming a negative pattern and forming a conductor pattern by coating, the non-main part is removed. Additionally, a method of transferring a conductor patterned on a substrate different from the insulating layer that becomes the base of the electronic component to the insulating layer may be used.

[0132] In addition, the method for forming the insulating layer, the opening, and the through hole is not limited to the above. It may also be a method of forming an opening by laser or drilling after crimping, spin coating, or spraying of an insulating material sheet.

[0133] In addition, the insulating material of the insulating layer is not limited to ceramic materials such as glass and ferrite as described above. It may also be an organic material such as epoxy resin, fluororesin, or polymer resin, or a composite material such as glass epoxy resin. However, when the electronic component is used for a matching coil application at high frequencies, a smaller dielectric constant and dielectric loss are desired.

[0134] In addition, the size of the electronic component is not limited to the above. In addition, the method for forming the external electrode is not limited to a method of performing plating processing on the external electrode exposed by cutting. A coating may also be formed on the external electrode exposed by cutting by impregnation of a conductor paste, sputtering method, etc., or a method of further performing plating processing thereon. Furthermore, like the case of forming the above coating and plating layer, it is not necessary to expose the external electrode to the outside of the electronic component. Thus, the so-called exposure from the base of the external electrode means that the external electrode has a portion not covered by the base, and this portion may be exposed to the outside of the electronic component or to other components.

[0135] Explanation of reference numerals

[0136] 1... Electronic component; 10... Base; 11... Insulating layer; 15... First end face; 16... Second end face; 17... Bottom face; 20... Coil; 20a... Outer periphery; 21... Coil conductor layer; 30, 30A to 30N... First external electrode; 31... First part; 32... Second part; 33... External electrode conductor layer; 40... Second external electrode; 41... First part; 42... Second part; 43... External electrode conductor layer.

Claims

1. An electronic component, wherein, Comprising: A substrate including two end faces facing each other and a bottom face connecting between the two end faces; A coil disposed within the substrate; External electrodes disposed on the substrate and electrically connected to the coil, On a first cross-section of the substrate intersecting the two end faces and the bottom face, the external electrode has a first portion extending along one of the end face and the bottom face of the substrate, and the first portion is embedded in the substrate to be exposed from the first face, The coil is configured such that the outer periphery of the coil faces the first face of the substrate, The substrate has light transmissivity, When the distance between the outer periphery of the coil and the first face of the substrate is small, the outer periphery can be seen through the first face of the substrate, When the distance between the outer periphery of the coil and the first face of the substrate is not small, the outer periphery cannot be seen through the first face of the substrate; When the first face refers to the bottom face of the substrate, the shortest distance b1 between the outer periphery of the coil and the first face of the substrate is greater than 0, and the minimum width a1 of the first portion and the shortest distance b1 between the outer periphery of the coil and the first face of the substrate satisfy b1 < (2 / 3) × a1; or When the first face refers to the end face of the substrate, the shortest distance d1 between the outer periphery of the coil and the first face of the substrate is greater than 0, and the minimum width c1 of the first portion and the shortest distance d1 between the outer periphery of the coil and the first face of the substrate satisfy d1 < (2 / 3) × c1.

2. The electronic component according to claim 1, wherein The substrate is composed of a plurality of insulating layers laminated in a direction intersecting the first cross-section of the substrate, and the coil includes a coil conductor layer wound around the insulating layer.

3. The electronic component according to claim 2, wherein The coil has a structure in which a plurality of the coil conductor layers electrically connected in series and having less than one turn are laminated.

4. The electronic component according to claim 2, wherein The external electrode includes two electrodes, a first external electrode and a second external electrode, electrically connected to one end and the other end of the coil respectively, The first external electrode is exposed from one of the two end faces and the bottom face, and the second external electrode is exposed from the other of the two end faces and the bottom face.

5. The electronic component according to claim 2, wherein The external electrode has a structure in which a plurality of external electrode conductor layers embedded in the substrate are laminated, and the external electrode conductor layer has a portion extending along the end face and the bottom face.

6. The electronic component according to claim 1, wherein The shortest distance between the outer periphery of the coil and the first face of the substrate is smaller than the minimum width of the first portion in a direction orthogonal to the first face.

7. The electronic component according to claim 1, wherein The substrate contains an insulating material mainly composed of borosilicate glass.

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