Multilayer electronic components

Abstract

To provide a multilayer electronic component that can suppress the occurrence of short-circuit defects caused by cracks. [Solution] The multilayer electronic component 1 comprises a sintered body 2, a first internal electrode 3, and a second internal electrode 4. The sintered body 2 has a layered structure. The first internal electrode 3 is provided on the first layered surface SF1. The second internal electrode 4 is provided on the second layered surface SF2. The first internal electrode 3 has a first opposing portion 31 facing the second internal electrode 4 in the layering direction, and a first lead portion 32 connecting the first opposing portion 31 and the first external electrode G1. The second internal electrode 4 has a second opposing portion 41 facing the first internal electrode 3 in the layering direction, and a second lead portion 42 connecting the second opposing portion 41 and the second external electrode G2. At least one of the lead portions, the first lead portion 32 and the second lead portion 42, is weaker in strength than the first opposing portion 31 or the second opposing portion 41.

Description

Technical Field

[0001] The present disclosure relates to a multilayer electronic component. More specifically, the present disclosure relates to a multilayer electronic component formed by laminating ceramics.

Background Art

[0002] Conventionally, there exist multilayer electronic components formed by laminating ceramics. Patent Document 1 describes a multilayer varistor. In the multilayer varistor described in Patent Document 1, external electrodes are formed on both end faces of a sintered body obtained by laminating ceramic layers and integrally sintering the same, a plurality of internal electrodes are embedded in the sintered body, and only one end face of each of the internal electrodes is alternately connected to the external electrodes. In the multilayer varistor, the internal electrodes are formed in a comb shape on a plane orthogonal to the thickness direction of the ceramic layers.

[0003] Patent Document 2 describes a multilayer semiconductor ceramic having a positive resistance temperature characteristic. The multilayer semiconductor ceramic described in Patent Document 2 is obtained by laminating ceramic sheets on which internal electrodes are formed such that the ceramic sheets and the internal electrodes are alternately arranged and one end of each internal electrode is alternately exposed in different directions, and integrally sintering the obtained laminate. A notch is formed in the internal electrode.

[0004] Patent Document 3 describes a multilayer chip varistor. The multilayer chip varistor described in Patent Document 3 is configured such that, among internal electrodes of the multilayer chip varistor in which varistor layers and internal electrodes are alternately stacked, the thickness of a lead electrode portion is greater than the thickness of an effective electrode portion.

Prior Art Literature

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

[0006] If the substrate on which the multilayer varistor with the above configuration is mounted is subjected to excessive stress due to bending, cracks may occur in the internal sintered body. If the cracks that occur inside span across the internal electrodes, a short circuit failure may occur.

[0007] The issues described above are common not only to multilayer varistors but also to multilayer electronic components formed by stacking ceramics.

[0008] The purpose of this disclosure is to provide a multilayer electronic component that can suppress the occurrence of short-circuit defects caused by cracks. [Means for solving the problem]

[0009] A multilayer electronic component according to one aspect of the present disclosure comprises a sintered body, a first internal electrode, and a second internal electrode. The sintered body has a multilayer structure in which a plurality of layers are stacked on a plurality of stacking surfaces. The plurality of stacking surfaces include at least a first stacking surface and a second stacking surface. The first internal electrode is provided on the first stacking surface. The second internal electrode is provided on the second stacking surface. The first internal electrode has a first opposing portion facing the second internal electrode in the stacking direction, and a first lead portion connecting the first opposing portion and the first external electrode. The second internal electrode has a second opposing portion facing the first internal electrode in the stacking direction, and a second lead portion connecting the second opposing portion and the second external electrode. At least one of the first lead portion and the second lead portion is weaker in strength than the first opposing portion or the second opposing portion. [Effects of the Invention]

[0010] According to this disclosure, it is possible to provide a multilayer electronic component that can suppress the occurrence of short-circuit defects caused by cracks. [Brief explanation of the drawing]

[0011] [Figure 1] Figure 1 is an external perspective view of a multilayer varistor according to one embodiment of the present disclosure. [Figure 2] Figure 2 is a perspective view of the same multilayer varistor. [Figure 3] Figure 3 is a top view of the same multilayer varistor. [Figure 4] Figure 4 is a bottom view of the same multilayer varistor. [Figure 5] Figure 5 is a cross-sectional view of section II in Figure 3. [Figure 6] Figure 6 is a plan view of the first and second internal electrodes shown above. [Figure 7] Figure 7 is a plan view of the first internal electrode and the second internal electrode of a multilayer varistor according to Modification 1 of one embodiment of the present disclosure. [Figure 8] Figure 8 is a plan view of the first internal electrode and the second internal electrode of a multilayer varistor according to Modification 2 of one embodiment of the present disclosure. [Figure 9] Figure 9 is a plan view of the first internal electrode and the second internal electrode of a multilayer varistor according to Modification 3 of one embodiment of the present disclosure. [Figure 10] Figure 10 is a cross-sectional view of a multilayer varistor according to Modification 4 of one embodiment of the present disclosure. [Figure 11] Figure 11 is a cross-sectional view of a multilayer varistor according to Modification 5 of one embodiment of the present disclosure. [Figure 12] Figure 12 is a cross-sectional view of a multilayer varistor according to Modification 6 of one embodiment of the present disclosure. [Modes for carrying out the invention]

[0012] Hereinafter, the multilayer varistor according to the embodiment will be described in detail with reference to the drawings. However, each drawing described in the following embodiments is a schematic diagram, and the dimensional ratio such as the size of each component does not necessarily reflect the actual dimensional ratio. In addition, the configuration described in the following embodiments is merely an example of the present disclosure. The present disclosure is not limited to the following embodiments, and various modifications can be made according to the design and the like as long as the effects of the present disclosure can be achieved.

[0013] (Embodiment) (1) Outline Hereinafter, an outline of the multilayer varistor 1 according to the present embodiment will be described with reference to FIGS. 1 to 6.

[0014] The multilayer varistor 1 is an electronic component having non-linear resistance characteristics and a function of protecting electronic devices from overvoltages such as surges (abnormal voltages) or ESD (electrostatic discharge). The multilayer varistor 1 is a chip varistor incorporating one varistor element. The multilayer varistor 1 corresponds to the "multilayer electronic component" in the present disclosure.

[0015] The multilayer varistor 1 includes a sintered body 2, a first internal electrode 3, and a second internal electrode 4.

[0016] The sintered body 2 has a multilayer structure in which a plurality of (three in FIG. 5) layers are laminated on a plurality of (two in FIG. 5) lamination surfaces. The two lamination surfaces include a first lamination surface SF1 and a second lamination surface SF2.

[0017] The first internal electrode 3 is provided on the first laminated surface SF1. The first internal electrode 3 has a first opposing portion 31 and a first extraction portion 32. The first opposing portion 31 faces the second internal electrode 4 in the laminated direction (the Z-axis direction in Figure 5). In this disclosure, "facing" means that at least a portion of the two objects (internal electrodes, etc.) intersect in that direction (such as the laminated direction), and may include the case where a layer (layer LY2 in Figure 5) is interposed between the two intersecting objects. The first extraction portion 32 connects the first opposing portion 31 and the first external electrode G1. In this embodiment, the first extraction portion 32 has less strength than the first opposing portion 31. In this disclosure, "strength" means the strength against stress applied to the sintered body 2 in the laminated direction (the Z-axis direction in Figure 5).

[0018] The second internal electrode 4 is provided on the second laminated surface SF2. The second internal electrode 4 has a second opposing portion 41 and a second leading portion 42. The second opposing portion 41 faces the first internal electrode 3 in the laminated direction (the Z-axis direction in Figure 5). The second leading portion 42 connects the second opposing portion 41 and the second external electrode G2. In this embodiment, the strength of the second leading portion 42 is weaker than that of the second opposing portion 41.

[0019] In the multilayer varistor 1 of this embodiment, a varistor element is formed between the first internal electrode 3 and the second internal electrode 4. When a surge voltage is applied between the first internal electrode 3 and the second internal electrode 4 in the varistor element, a surge current flows.

[0020] Incidentally, while multilayer varistors 1 are generally used mounted on a substrate, if the substrate on which the multilayer varistor 1 is mounted flexes, excessive stress may be applied from the substrate, causing cracks to occur inside the sintered body 2. These cracks can propagate not only in a direction parallel to the lamination plane of the sintered body 2 (the plane parallel to the XY plane in Figure 5), but also in the lamination direction of the sintered body 2 (the Z-axis direction in Figure 5). If the cracks propagate across the first internal electrode 3 and the second internal electrode 4, a short-circuit failure may occur. If a short-circuit failure occurs in the multilayer varistor 1, not only will the multilayer varistor 1 cease to function, but the entire electronic device, including the multilayer varistor 1, may also cease to operate.

[0021] Therefore, in the laminated varistor 1 of this embodiment, the strength of the first drawout portion 32 in the first internal electrode 3 is weaker than the strength of the first opposing portion 31. As a result, if a crack occurs inside the sintered body 2, the first drawout portion 32 is more likely to break than the first opposing portion 31. When the first drawout portion 32 breaks due to a crack, the crack is less likely to propagate from the first drawout portion 32 to the first opposing portion 31.

[0022] Furthermore, since the strength of the second extraction portion 42 in the second internal electrode 4 is weaker than the strength of the second opposing portion 41, if a crack occurs inside the sintered body 2, the second extraction portion 42 is more likely to break than the second opposing portion 41. If the second extraction portion 42 breaks due to a crack, the crack is less likely to propagate from the second extraction portion 42 to the second opposing portion 41.

[0023] As a result, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4. This makes it possible to suppress the occurrence of short-circuit failures in the multilayer varistor 1.

[0024] (2) Details The stacked varistor 1 according to this embodiment will be described in detail below with reference to Figures 1 to 6.

[0025] Figure 1 is an external perspective view of the multilayer varistor 1. Figure 2 is a perspective view of the multilayer varistor 1. Figure 3 is a top view of the multilayer varistor 1. Figure 4 is a bottom view of the multilayer varistor 1. Figure 5 is a cross-sectional view of section II of Figure 3. Figure 6 is a plan view of the first internal electrode 3 and the second internal electrode 4. In Figure 2, for convenience, only the first internal electrode 3 and the second internal electrode 4 are shown with solid lines, while other components are shown with dashed or dotted lines. Also, in Figures 3 and 4, the first internal electrode 3 and the second internal electrode 4 are shown with dashed lines.

[0026] In the following explanation, the long side direction (left-right direction) of the stacked varistor 1 is referred to as the "X-axis direction," the depth direction (front-back direction) of the stacked varistor 1 is referred to as the "Y-axis direction," and the thickness direction (up-down direction) of the stacked varistor 1 is referred to as the "Z-axis direction." The X, Y, and Z axes that define these directions are mutually orthogonal. Furthermore, the positive direction of the X-axis is defined as the right side, the positive direction of the Y-axis as the front side, and the positive direction of the Z-axis as the top side. However, these directions are merely examples and are not intended to limit the direction in which the stacked varistor 1 can be used. Also, the arrows indicating the "X-axis direction," "Y-axis direction," and "Z-axis direction" in the drawings are for illustrative purposes only and do not represent actual dimensions.

[0027] (2.1) Sintered body As described above, the laminated varistor 1 of this embodiment includes a sintered body 2.

[0028] The sintered body 2 is formed in the shape of a rectangular parallelepiped, for example, with a length of 1.6 mm, a width of 0.8 mm, and a height of 0.8 mm (see Figure 1). Although the outer shape of the sintered body 2 is shown as a rectangular parallelepiped in Figure 1, the corners of the sintered body 2 may be chamfered as appropriate, and the corners of the sintered body 2 may be rounded. The surface of the sintered body 2 may be covered with a high-resistance layer that has a higher resistance than the sintered body 2.

[0029] As shown in Figures 1 to 5, the sintered body 2 has a first end face S11 and a second end face S12, a first side surface S21 and a second side surface S22, and a first main surface S31 and a second main surface S32. The first end face S11 and the second end face S12 face each other in the X-axis direction. The first side surface S21 and the second side surface S22 face each other in the Y-axis direction. The first main surface S31 and the second main surface S32 face each other in the Z-axis direction. In other words, the X-axis direction corresponds to the "first direction" in which the first end face S11 and the second end face S12 face each other. The Y-axis direction corresponds to the "second direction" in which the first side surface S21 and the second side surface S22 face each other. The Z-axis direction corresponds to the "third direction" in which the first main surface S31 and the second main surface S32 face each other. The multilayer varistor 1 is mounted on a substrate, for example, with the second main surface S32 facing the substrate.

[0030] The sintered body 2 is composed of ceramic components having nonlinear resistance characteristics. This sintered body 2 may, for example, have ZnO as its main component and may contain at least one of Bi2O3, Co2O3, MnO2, and Sb2O3 as a minor component, and Pr6O 11 It may also contain at least one of CaCO3 and Cr2O3. The sintered body 2 is formed by sintering ZnO and precipitating other by-components at its grain boundaries. The grain boundary barriers formed between the ZnO particles result in nonlinear resistance characteristics. The sintered body 2 is formed, for example, by stacking multiple (three in Figure 5) layers mainly composed of ZnO in a third direction (Z-axis direction) and then sintering them. Therefore, the "third direction" corresponds to the "stack direction" of the stacked varistor 1. In this embodiment, the sintered body 2 has a stacked structure in which the first layer LY1, the second layer LY2, and the third layer LY3 are stacked on the first stacking surface SF1 and the second stacking surface SF2 (see Figure 5). As shown in Figure 5, the sintered body 2 has three layers LY1 to LY3 stacked in the third direction. The first layer LY1 to the third layer LY3 are stacked in the order of first layer LY1, second layer LY2, and third layer LY3 from top to bottom. In the following, the lamination surface between the first layer LY1 and the second layer LY2 may be referred to as the first lamination surface SF1. The lamination surface between the second layer LY2 and the third layer LY3 may be referred to as the second lamination surface SF2.

[0031] (2.2) External electrode As shown in Figure 1, the stacked varistor 1 further comprises a first external electrode G1 and a second external electrode G2.

[0032] The first external electrode G1 is provided on the first end face S11 of the sintered body 2. The second external electrode G2 is provided on the second end face S12 of the sintered body 2.

[0033] The first external electrode G1 and the second external electrode G2 may contain a metal and may also contain a glass component. Examples of metals include Ag, Pd, Pt, Au, Cu, etc., with Ag being preferable. The glass component refers to an amorphous substance that has a softening point. Examples of glass components include silica-based glass and zinc borosilicate glass.

[0034] The first external electrode G1 and the second external electrode G2 are formed, for example, by dipping the first end face S11 and the second end face S12 of the sintered body 2 with conductive paste.

[0035] The multilayer varistor 1 may also be provided with plated electrodes so as to cover at least a portion of the first external electrode G1 and the second external electrode G2. The plated electrodes can be formed on at least a portion of the first external electrode G1 and the second external electrode G2, for example, by electroplating Ni, or by sequentially plating Ni and Sn.

[0036] The first external electrode G1 is provided on the entire surface of the first end face S11 and on the left ends of the first side surface S21, the second side surface S22, the first main surface S31, and the second main surface S32. The first external electrode G1 is electrically connected to the first internal electrode 3.

[0037] The second external electrode G2 is provided on the entire surface of the second end face S12 and on the right ends of the first side surface S21, the second side surface S22, the first main surface S31, and the second main surface S32. The second external electrode G2 is electrically connected to the second internal electrode 4.

[0038] (2.3) Internal electrode As described above, the stacked varistor 1 of this embodiment includes a first internal electrode 3 and a second internal electrode 4.

[0039] The first internal electrode 3 and the second internal electrode 4 are arranged in the order of the first internal electrode 3 and the second internal electrode 4 from the first main surface S31 side of the sintered body 2.

[0040] The first internal electrode 3 is provided on the first laminated surface SF1. The second internal electrode 4 is provided on the second laminated surface SF2. In the third direction, the second layer LY2 is positioned between the first internal electrode 3 and the second internal electrode 4. That is, the first internal electrode 3 and the second internal electrode 4 are positioned separated in the third direction. The first internal electrode 3 and the second internal electrode 4 are separated from each other and are not in contact.

[0041] As shown in Figure 3, the first internal electrode 3 has a first opposing portion 31 and a first leading portion 32. The first leading portion 32 has the same width as the first opposing portion 31 in the second direction (Y-axis direction) and protrudes from the first opposing portion 31 to the left (negative side in the X-axis direction) along the first direction. The left end of the first leading portion 32 is electrically connected to the first external electrode G1. The first internal electrode 3 is electrically connected to the first external electrode G1. The first leading portion 32 electrically connects the first opposing portion 31 and the first external electrode G1.

[0042] As shown in Figure 4, the second internal electrode 4 has a second opposing portion 41 and a second leading portion 42. The second leading portion 42 has the same width as the second opposing portion 41 in the second direction (Y-axis direction) and protrudes from the second opposing portion 41 to the right (positive side in the X-axis direction) along the first direction. The right end of the second leading portion 42 is electrically connected to the second external electrode G2. The second internal electrode 4 is electrically connected to the second external electrode G2. The second leading portion 42 electrically connects the second opposing portion 41 and the second external electrode G2.

[0043] The width of the first opposing portion 31 in the second direction (Y-axis direction) is formed to be equal to, for example, the width of the second opposing portion 41 in the second direction (Y-axis direction). Also, the width of the first opposing portion 31 in the first direction (X-axis direction) is formed to be equal to, for example, the width of the second opposing portion 41 in the first direction (X-axis direction).

[0044] As shown in Figure 3 or Figure 4, the first internal electrode 3 and the second internal electrode 4 are arranged such that, when viewed from above or below, at least a portion of the first internal electrode 3 and at least a portion of the second internal electrode 4 overlap. This forms a varistor element between the first internal electrode 3 and the second internal electrode 4. More specifically, as shown in Figure 3 or Figure 4, the first opposing portion 31 of the first internal electrode 3 overlaps with the second opposing portion 41 of the second internal electrode 4 when viewed from above or below. In the multilayer varistor 1 of this embodiment, a varistor element is formed between the first opposing portion 31 of the first internal electrode 3 and the second opposing portion 41 of the second internal electrode. Preferably, the capacitance between the first internal electrode 3 and the second internal electrode 4 of the varistor element is 700 pF or less.

[0045] In this embodiment, as shown in Figure 3, the first internal electrode 3 is rectangular in plan view, with the longer side being in the first direction (X-axis direction). The first opposing portion 31 is the right half of the first internal electrode 3, and the first leading portion 32 is the left half of the first internal electrode 3. In other words, the first opposing portion 31 and the first leading portion 32 are, for example, the same size and are the same rectangle with the longer side being in the first direction (X-axis direction). The first leading portion 32 extends toward the first external electrode G1. In this embodiment, the first opposing portion 31 and the first leading portion 32 are the same size, but they may be of different sizes.

[0046] In this embodiment, as shown in Figure 4, the second internal electrode 4 is rectangular in plan view, with the longer side being in the first direction (X-axis direction). The second opposing portion 41 is the left half of the second internal electrode 4, and the second leading portion 42 is the right half of the second internal electrode 4. In other words, the second opposing portion 41 and the second leading portion 42 are the same size and are the same rectangle with the longer side being in the first direction (X-axis direction). The second leading portion 42 extends toward the second external electrode G2.

[0047] Furthermore, in the stacked varistor 1 of this embodiment, as shown in Figure 6, the first lead-out portion 32 of the first internal electrode 3 is provided with a plurality (four in Figure 6) of openings 7. Each of the four openings 7 penetrates in the third direction (direction of the Z axis). Each of the four openings 7 is a rectangular hole in plan view, with the longer side of the rectangle being in the direction from the first opposing portion 31 toward the first external electrode G1 (positive direction of the X axis). The four openings 7 of the first lead-out portion 32 are arranged in a 2x2 matrix in plan view. When forming the first internal electrode 3 on the first stacked surface SF1, the matrix pattern of the four openings 7 can be formed on the first lead-out portion 32 by masking the parts corresponding to the four openings 7 with metal or the like.

[0048] As described above, the first lead-out section 32 has the function of electrically connecting the first opposing section 31 and the first external electrode G1. In this embodiment, by providing four openings 7 in the first lead-out section 32, the first lead-out section 32 has multiple (three in Figure 6) parts that electrically connect the first opposing section 31 and the first external electrode G1. The first part is a part formed at the front end of the first lead-out section 32 by two openings 7 provided on the front side of the first lead-out section 32. The second part is a part formed between the two openings 7 provided on the front side of the first lead-out section 32 and the two openings 7 provided on the rear side of the first lead-out section 32. The third part is a part formed at the rear end of the first lead-out section 32 by two openings 7 provided on the rear side of the first lead-out section 32. The first, second, and third portions of the first lead-out portion 32 are all aligned in the direction from the first opposing portion 31 toward the first external electrode G1, and are integrally formed at the left end, center, and right end of the first lead-out portion 32.

[0049] Furthermore, in the stacked varistor 1 of this embodiment, as shown in Figure 6, an opening 7 is provided in the second lead-out portion 42 of the second internal electrode 4. The opening 7 penetrates in the third direction (direction of the Z axis). The second lead-out portion 42 is provided with multiple (four in Figure 6) openings 7. Each of the four openings 7 is a rectangular hole in plan view, and is a rectangular hole with the longer side in the first direction (X axis direction) toward the second external electrode G2 from the second opposing portion 41. The four openings 7 of the second lead-out portion 42 are arranged in a 2x2 matrix in plan view. When forming the second internal electrode 4 on the second stacked surface SF2, a matrix pattern of four openings 7 can be formed in the second lead-out portion 42 by masking the parts corresponding to the four openings 7 with metal or the like.

[0050] As described above, the second lead-out section 42 has the function of electrically connecting the second opposing section 41 and the second external electrode G2. In this embodiment, by providing four openings 7 in the second lead-out section 42, the second lead-out section 42 has multiple (three in Figure 6) parts that electrically connect the second opposing section 41 and the second external electrode G2. The first part is a part formed at the front end of the second lead-out section 42 by two openings 7 provided on the front side of the second lead-out section 42. The second part is a part formed between the two openings 7 provided on the front side of the second lead-out section 42 and the two openings 7 provided on the rear side of the second lead-out section 42. The third part is a part formed at the rear end of the second lead-out section 42 by two openings 7 provided on the rear side of the second lead-out section 42. The first, second, and third portions of the second lead-out portion 42 are all aligned in the direction from the first opposing portion 31 toward the first external electrode G1, and are integrally formed at the left end, center, and right end of the second lead-out portion 42.

[0051] (2.4) Effects The multilayer varistor 1 with the above configuration is generally mounted on a substrate (not shown) with the second main surface S32 of the sintered body 2 facing the substrate. When the multilayer varistor 1 is mounted on the substrate, if the substrate flexes and the varistor 1 is subjected to excessive stress from the substrate, cracks may occur inside the sintered body 2. The cracks that occur can propagate not only in a direction parallel to the lamination plane of the sintered body 2 (a plane parallel to the XY plane), but also in the lamination direction of the sintered body 2 (in the Z-axis direction). If the cracks span the first internal electrode 3 and the second internal electrode 4, a short-circuit failure may occur. If a short-circuit failure occurs in the multilayer varistor 1, not only will the multilayer varistor 1 cease to function, but the entire electronic device including the multilayer varistor 1 may cease to operate.

[0052] Therefore, in the laminated varistor 1 of this embodiment, as shown in Figure 6, the first internal electrode 3 is provided with four openings 7 that penetrate in the third direction (Z-axis direction) in the first extraction portion 32. As a result, the first extraction portion 32 is divided into three parts that electrically connect the first opposing portion 31 and the first external electrode G1. The strength of the first extraction portion 32 is weaker than the strength of the first opposing portion 31. As a result, if a crack occurs inside the sintered body 2, a part of the first extraction portion 32 is more likely to break than the first opposing portion 31. If a part of the first extraction portion 32 (first to third portions) breaks due to a crack, the crack is less likely to propagate from the first extraction portion 32 to the first opposing portion 31.

[0053] Furthermore, in the second internal electrode 4, four openings 7 are provided in the second extraction portion 42, thereby dividing the second extraction portion 42 into three parts that electrically connect the second opposing portion 41 and the second external electrode G2. In this way, the strength of the second extraction portion 42 is made weaker than the strength of the second opposing portion 41. As a result, if a crack occurs inside the sintered body 2, a part of the second extraction portion 42 (the first to third parts) is more likely to break than the second opposing portion 41. If a part of the second extraction portion 42 breaks due to a crack, the crack is less likely to propagate from the second extraction portion 42 to the second opposing portion 41.

[0054] As a result, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4. The multilayer varistor 1 of this embodiment can suppress the occurrence of short-circuit failures.

[0055] In the stacked varistor 1 of this embodiment, the multiple (four in Figure 6) openings 7 of the first drawer section 32 and the second drawer section 42 are arranged in a 2x2 matrix in plan view (see Figure 6), but they may also be arranged in an nxm matrix (n is an integer of 1 or more than 3, and m is an integer of 1 or more than 3). Furthermore, the multiple openings 7 may also be arranged in a 2x3 or 3x2 matrix in plan view.

[0056] Furthermore, in the stacked varistor 1 of this embodiment, the openings 7 of the first lead-out section 32 and the second lead-out section 42 are rectangular in plan view (see Figure 6), but they may also be circular or elliptical in plan view. In short, the openings 7 may have any other shape as long as they penetrate in the third direction (Z-axis direction).

[0057] In the stacked varistor 1 of this embodiment, the strength of the first lead portion 32 of the first internal electrode 3 is made weaker than that of the first opposing portion 31, and the strength of the second lead portion 42 of the second internal electrode 4 is made weaker than that of the second opposing portion 41. Alternatively, only the strength of the first lead portion 32 of the first internal electrode 3 may be made weaker than that of the first opposing portion 31. Also, only the strength of the second lead portion 42 of the second internal electrode 4 may be made weaker than that of the second opposing portion 41.

[0058] (3) Variant The above embodiments are merely one of many embodiments of this disclosure. The above embodiments can be modified in various ways depending on the design, etc., as long as they achieve the objectives of this disclosure.

[0059] The following lists modifications of the above embodiment. The modifications described below can be combined and applied as appropriate. In the following, the above embodiment may also be referred to as the basic configuration.

[0060] (3.1) Variation 1 In the stacked varistor 1 of the above embodiment, multiple openings 7 are provided in the first lead-out portion 32 of the first internal electrode 3 and the second lead-out portion 42 of the second internal electrode 4 (see Figure 6). Alternatively, multiple comb teeth may be provided in the first lead-out portion 32 of the first internal electrode 3 and the second lead-out portion 42 of the second internal electrode 4.

[0061] Figure 7 is a plan view of the first internal electrode 3A and the second internal electrode 4A of the multilayer varistor 1A according to Modification 1. Note that the configuration of the multilayer varistor 1A according to Modification 1, other than the first internal electrode 3A and the second internal electrode 4A, is the same as the basic configuration of the multilayer varistor 1, and therefore its explanation is omitted. For convenience, only the first internal electrode 3A and the second internal electrode 4A according to Modification 1 are shown in Figure 7. As shown in Figure 7, the first lead-out portion 32A of the first internal electrode 3A is formed in a comb-like shape in plan view. In other words, the first lead-out portion 32A is provided with multiple (five in Figure 7) comb teeth 8.

[0062] More specifically, in the first lead-out section 32A, five comb teeth 8 protrude from the first opposing section 31 toward the first external electrode G1. Each comb tooth 8 is rectangular in plan view, with the longer side of the rectangle being in the direction toward the first opposing section 31 toward the first external electrode G1 (negative direction of the X-axis).

[0063] As described above, the first lead portion 32A has the function of electrically connecting the first opposing portion 31 and the first external electrode G1. In this embodiment, by forming the first lead portion 32A in a comb-like shape, the first lead portion 32A has multiple (five in Figure 7) parts that electrically connect the first opposing portion 31 and the first external electrode G1.

[0064] Furthermore, as shown in Figure 7, the second lead-out portion 42A of the second internal electrode 4A is formed in a comb-like shape in plan view. In other words, the second lead-out portion 42A is provided with multiple (five in Figure 7) comb teeth 8.

[0065] In the second lead-out section 42A, five comb teeth 8 protrude from the second opposing section 41 toward the second external electrode G2. Each comb tooth 8 is rectangular in plan view, with the longer side of the rectangle being in the direction toward the second external electrode G2 from the second opposing section 41 (the positive direction of the X-axis).

[0066] As described above, the second lead portion 42A has the function of electrically connecting the second opposing portion 41 and the second external electrode G2. In this embodiment, by forming the second lead portion 42A in a comb-like shape, the second lead portion 42A has multiple (five in Figure 7) parts that electrically connect the second opposing portion 41 and the second external electrode G2.

[0067] In the laminated varistor 1A of the modified example 1, a plurality of comb teeth 8 are formed in the first lead portion 32A of the first internal electrode 3A, thereby dividing the first lead portion 32A into five parts that electrically connect the first opposing portion 31 and the first external electrode G1. The planar strength of the first lead portion 32A is weaker than that of the first opposing portion 31. As a result, if a crack occurs inside the sintered body 2, a part of the first lead portion 32A is more likely to break than the first opposing portion 31. If a part of the first lead portion 32A breaks due to a crack, the crack is less likely to propagate from the first lead portion 32A to the first opposing portion 31.

[0068] Furthermore, in the laminated varistor 1A of the modified example 1, by forming multiple comb teeth 8 in the second lead portion 42A of the second internal electrode 4A, the second lead portion 42A is divided into five parts that electrically connect the second opposing portion 41 and the second external electrode G2. The planar strength of the second lead portion 42A is weaker than that of the second opposing portion 41. As a result, if a crack occurs inside the sintered body 2, a part of the second lead portion 42A is more likely to break than the second opposing portion 41. If a part of the second lead portion 42A breaks due to a crack, the crack is less likely to propagate from the second lead portion 42A to the second opposing portion 41.

[0069] Therefore, with the multilayer varistor 1A of the modified example 1, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4, thus suppressing the occurrence of short-circuit failures.

[0070] (3.2) Variation 2 In the stacked varistor 1 of the above embodiment, the first lead-out portion 32 of the first internal electrode 3 and the second lead-out portion 42 of the second internal electrode 4 are each provided with an opening 7 that penetrates in the third direction (Z-axis direction) (see Figure 6). Alternatively, the first lead-out portion 32 of the first internal electrode 3 and the second lead-out portion 42 of the second internal electrode 4 may each be recessed in a direction intersecting the first direction (X-axis direction).

[0071] Figure 8 is a plan view of the first internal electrode 3B and the second internal electrode 4B of the laminated varistor 1B according to Modification 2. Note that the configuration of the laminated varistor 1B according to Modification 2, other than the first internal electrode 3B and the second internal electrode 4B, is the same as the basic configuration of the laminated varistor 1, so its explanation is omitted. In Figure 8, for convenience, only the first internal electrode 3B and the second internal electrode 4B are shown. As shown in Figure 8, the first lead-out portion 32B extends in the direction toward the first external electrode G1 (negative direction of the X axis). The second lead-out portion 42B extends in the direction toward the second external electrode G2 (positive direction of the X axis).

[0072] The first lead-out section 32B is provided with a first recess 9. In a plan view, the first recess 9 of the first lead-out section 32B is recessed in a second direction (Y-axis direction) that intersects with the first direction (X-axis direction) toward the first external electrode G1. More specifically, the first recess 9 is provided at the front end and rear end of the first lead-out section 32B in the short-side direction (Y-axis direction). The first recess 9 provided at the front end of the first lead-out section 32B is V-shaped in a plan view and is recessed toward the rear (negative direction in the Y-axis direction). The first recess 9 provided at the rear end of the first lead-out section 32B is V-shaped in a plan view and is recessed toward the front (positive direction in the Y-axis direction).

[0073] The second lead-out section 42B is provided with a first recess 9. In a plan view, the first recess 9 of the second lead-out section 42B is recessed in a second direction (Y-axis direction) that intersects with the first direction (X-axis direction) toward the second external electrode G2. More specifically, the first recess 9 is provided at the front end and rear end of the second lead-out section 42B in the short-side direction (Y-axis direction). The first recess 9 provided at the front end of the second lead-out section 42B is V-shaped in a plan view and is recessed toward the rear (negative direction in the Y-axis direction). The first recess 9 provided at the rear end of the second lead-out section 42B is V-shaped in a plan view and is recessed toward the front (positive direction in the Y-axis direction).

[0074] In the modified example 2 of the laminated varistor 1B, two V-shaped first recesses 9 are provided in the first lead portion 32B of the first internal electrode 3B, making the width of the first lead portion 32B in the front-to-back direction (Y-axis direction) narrower than that of the first opposing portion 31. As a result, the strength of the first lead portion 32B in the planar direction becomes weaker than that of the first opposing portion 31. If a crack occurs inside the sintered body 2, a part of the first lead portion 32B becomes more prone to fracture than the first opposing portion 31. If a part of the first lead portion 32B fractures due to a crack, the crack is less likely to propagate from the first lead portion 32B to the first opposing portion 31.

[0075] Furthermore, in the modified example 2 of the laminated varistor 1B, two V-shaped first recesses 9 are provided in the second lead portion 42B of the second internal electrode 4B, making the width of the second lead portion 42B in the front-to-back direction (Y-axis direction) narrower than that of the second opposing portion 41. As a result, the strength of the second lead portion 42B in the planar direction becomes weaker than that of the second opposing portion 41. If a crack occurs inside the sintered body 2, a part of the second lead portion 42B becomes more prone to fracture than the second opposing portion 41. If a part of the second lead portion 42B fractures due to a crack, the crack is less likely to propagate from the second lead portion 42B to the first opposing portion 31.

[0076] Therefore, according to the laminated varistor 1B of the modified example 2, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4, thus suppressing the occurrence of short-circuit failures.

[0077] In addition, in the stacked varistor 1B of the modified example 2, as shown in Figure 8, the first lead-out portion 32B of the first internal electrode 3B is provided with two V-shaped first recesses 9, but one V-shaped first recess 9 may be provided instead. That is, one first recess 9 may be provided at the front end of the first lead-out portion 32B so as to be recessed toward the rear (negative direction in the Y-axis direction). One first recess 9 may be provided at the rear end of the first lead-out portion 32B so as to be recessed toward the front (positive direction in the Y-axis direction).

[0078] Similarly, as shown in Figure 8, the second lead-out portion 42B of the second internal electrode 4B is provided with two V-shaped first recesses 9, but it is also possible to provide only one V-shaped first recess 9. In other words, one first recess 9 may be provided at the front end of the second lead-out portion 42B so as to be recessed towards the rear (negative direction in the Y-axis direction), or one first recess 9 may be provided at the rear end of the second lead-out portion 42B so as to be recessed towards the front (positive direction in the Y-axis direction).

[0079] In the stacked varistor 1B of the modified example 2, as shown in Figure 8, the first lead portion 32B of the first internal electrode 3B is electrically connected to the first opposing portion 31 and the first external electrode G1 via a narrow portion. The second lead portion 42B of the second internal electrode 4B is electrically connected to the second opposing portion 41 and the second external electrode G2 via a narrow portion. The first lead portion 32B may electrically connect the first opposing portion 31 and the first external electrode G1 via multiple portions, and the second lead portion 42B may electrically connect the second opposing portion 41 and the second external electrode G2 via multiple portions. In other words, in the stacked varistor 1B of the modified example 2, multiple first internal electrodes 3B having the first lead portion 32B shown in Figure 8 may be arranged in the front-to-back direction (Y-axis direction), and they may be formed as a single unit with respect to each other. Furthermore, a plurality of second internal electrodes 4B having the second lead portion 42B shown in Figure 8 may be arranged in a line in the front-to-back direction (Y-axis direction), and they may be formed as a single unit with respect to each other. This makes it more difficult for the first lead portion 32B and the second lead portion 42B to break in the front-to-back direction (Y-axis direction).

[0080] (3.3) Modification example 3 In the modified example 2 of the stacked varistor 1B described above, one first recess 9 is provided at the front end and one at the rear end of the first lead-out portion 32 of the first internal electrode 3, and one first recess 9 is provided at the front end and one at the rear end of the second lead-out portion 42 of the second internal electrode 4 (see Figure 8). Alternatively, multiple first recesses 9 may be provided at the front end and one at the rear end of the first lead-out portion 32 of the first internal electrode 3, and multiple first recesses 9 may be provided at the front end and one at the rear end of the second lead-out portion 42 of the second internal electrode 4.

[0081] Figure 9 is a plan view of the first internal electrode 3C and the second internal electrode 4C of a stacked varistor 1C according to a modified example 3 of one embodiment of the present disclosure. As shown in Figure 9, the first lead portion 32C is provided with a plurality (two in Figure 9) of first recesses 9 at its front end and rear end in the short direction (Y-axis direction). The two first recesses 9 at the front end of the first lead portion 32C are V-shaped in plan view and are recessed toward the rear (negative direction in the Y-axis direction). The two first recesses 9 at the rear end of the first lead portion 32C are V-shaped in plan view and are recessed toward the front (positive direction in the Y-axis direction).

[0082] Furthermore, the second extension section 42C has multiple (two in Figure 9) first recesses 9 at its front and rear ends in the shorter direction (Y-axis direction). The two first recesses 9 at the front end of the second extension section 42C are V-shaped in plan view and are recessed toward the rear (negative direction in the Y-axis direction). The two first recesses 9 at the rear end of the second extension section 42C are V-shaped in plan view and are recessed toward the front (positive direction in the Y-axis direction).

[0083] In the modified example 3 of the laminated varistor 1C, four first recesses 9 are provided in the first lead portion 32C of the first internal electrode 3C, making the width of the first lead portion 32C in the front-to-back direction (Y-axis direction) narrower than that of the first opposing portion 31. As a result, the strength of the first lead portion 32C in the planar direction is weaker than that of the first opposing portion 31. If a crack occurs inside the sintered body 2, a part of the first lead portion 32C is more likely to break than the first opposing portion 31. If a part of the first lead portion 32C breaks due to a crack, the crack is less likely to propagate from the first lead portion 32C to the first opposing portion 31.

[0084] Furthermore, in the laminated varistor 1C of the modified example 3, four first recesses 9 are provided in the second lead portion 42C of the second internal electrode 4C, making the width of the second lead portion 42C in the front-to-back direction (Y-axis direction) narrower than that of the second opposing portion 41. As a result, the strength of the second lead portion 42C in the planar direction is weaker than that of the second opposing portion 41. If a crack occurs inside the sintered body 2, a part of the second lead portion 42C is more likely to break than the second opposing portion 41. If a part of the second lead portion 42C breaks due to a crack, the crack is less likely to propagate from the second lead portion 42C to the second opposing portion 41.

[0085] Therefore, with the multilayer varistor 1C of modified example 3, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4, thus suppressing the occurrence of short-circuit failures.

[0086] In the stacked varistor 1C of the modified example 3, as shown in Figure 9, the first lead portion 32C of the first internal electrode 3C electrically connects the first opposing portion 31 and the first external electrode G1 via a narrow portion, and the second lead portion 42C of the second internal electrode 4C electrically connects the second opposing portion 41 and the second external electrode G2 via a narrow portion. The first lead portion 32C may electrically connect the first opposing portion 31 and the first external electrode G1 via multiple narrow portions, and the second lead portion 42C may electrically connect the second opposing portion 41 and the second external electrode G2 via multiple narrow portions. In other words, in the stacked varistor 1C of the modified example 3, multiple first internal electrodes 3C having the narrow first lead portion 32C shown in Figure 9 may be arranged in a row in the front-to-back direction (Y-axis direction), and they may be formed as a single unit with respect to each other. Furthermore, a plurality of second internal electrodes 4C, each having a narrow second lead portion 42C as shown in Figure 9, may be arranged in a line in the front-to-back direction (Y-axis direction), and they may be formed integrally with one another. This makes it more difficult for the first lead portion 32C and the second lead portion 42C to break in the front-to-back direction (Y-axis direction).

[0087] (3.4) Modification 4 In the stacked varistor 1 of the above embodiment, openings 7 are provided in the first lead portion 32 of the first internal electrode 3 and the second lead portion 42 of the second internal electrode 4 (see Figure 6). However, the thickness of the first lead portion 32 of the first internal electrode 3 in the third direction (Z-axis direction in Figure 6) may be smaller than the thickness of the first opposing portion 31. Similarly, the thickness of the second lead portion 42 of the second internal electrode 4 in the third direction may be smaller than the thickness of the second opposing portion 41.

[0088] Figure 10 is a cross-sectional view of a multilayer varistor 1D according to a modified example 4 of one embodiment of the present disclosure. As shown in Figure 10, the thickness of the first lead portion 32D of the first internal electrode 3D in the third direction (Z-axis direction in Figure 10) is smaller than the thickness of the first opposing portion 31.

[0089] More specifically, in the first laminated surface SF1, the thickness of the first lead portion 32D of the first internal electrode 3D is half the thickness of the first opposing portion 31. For example, when forming the first internal electrode 3D on the first laminated surface SF1, first, a first electrode layer 31a is formed in the region corresponding to the first opposing portion 31 and the first lead portion 32D on the first laminated surface SF1. Next, a second electrode layer 31b with the same thickness as the first electrode layer 31a is formed in the region corresponding to the first opposing portion 31. In this way, a first internal electrode 3D can be formed on the first laminated surface SF1 in which the thickness of the first lead portion 32D is half the thickness of the first opposing portion 31.

[0090] Furthermore, the thickness of the second lead portion 42D of the second internal electrode 4D in the third direction (Z-axis direction in Figure 10) is smaller than the thickness of the second opposing portion 41.

[0091] More specifically, in the second laminated surface SF2, the thickness of the second lead portion 42D of the second internal electrode 4D is half the thickness of the second opposing portion 41. For example, when forming the second internal electrode 4D on the second laminated surface SF2, first, a first electrode layer 41a is formed in the region corresponding to the second opposing portion 41 and the second lead portion 42D on the second laminated surface SF2. Next, a second electrode layer 41b with the same thickness as the first electrode layer 41a is formed in the region corresponding to the second opposing portion 41. In this way, a second internal electrode 4D can be formed on the second laminated surface SF2 in which the thickness of the second lead portion 42D is half the thickness of the second opposing portion 41.

[0092] In the modified example 4, the laminated varistor 1D, as shown in Figure 10, has a thickness in the third direction (Z-axis direction in Figure 10) of the first drawer portion 32D that is smaller than the thickness of the first opposing portion 31. As a result, the first drawer portion 32D has less strength in the third direction (Z-axis direction in Figure 10) than the first opposing portion 31. Consequently, if a crack occurs inside the sintered body 2, a portion of the first drawer portion 32D is more likely to break than the first opposing portion 31. When a portion of the first drawer portion 32D breaks due to a crack, the crack is less likely to propagate from the first drawer portion 32D to the first opposing portion 31.

[0093] Furthermore, according to the laminated varistor 1D of the modified example 4, as shown in Figure 10, the thickness of the second draw portion 42D in the third direction (Z-axis direction in Figure 10) is smaller than the thickness of the second opposing portion 41. As a result, the second draw portion 42D has weaker strength in the third direction (Z-axis direction in Figure 10) than the second opposing portion 41. Consequently, if a crack occurs inside the sintered body 2, a part of the second draw portion 42D is more likely to break than the second opposing portion 41. When a part of the second draw portion 42D breaks due to a crack, the crack is less likely to propagate from the second draw portion 42D to the second opposing portion 41.

[0094] Therefore, according to the multilayer varistor 1D of modified example 4, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4, thus suppressing the occurrence of short-circuit failures.

[0095] In the cross-sectional view of Figure 10, the first lead portion 32D of the first internal electrode 3D electrically connects the first opposing portion 31 and the first external electrode G1 via a thin portion, and the second lead portion 42D of the second internal electrode 4D electrically connects the second opposing portion 41 and the second external electrode G2 via a thin portion. The first lead portion 32D may electrically connect the first opposing portion 31 and the first external electrode G1 via multiple thin portions, and the second lead portion 42D may electrically connect the second opposing portion 41 and the second external electrode G2 via multiple thin portions. For example, in the first internal electrode 3D of the laminated varistor 1D of Modified Example 4, multiple thin first lead portions 32D may be formed in a comb-like shape in the front-rear direction (Y-axis direction in Figure 10). Similarly, in the second internal electrode 4D, a plurality of second lead portions 42D with a small thickness may be formed in a comb-like manner in the front-to-back direction (Y-axis direction in Figure 10). This makes it more difficult for each of the first lead portion 32D and the second lead portion 42D to break in the front-to-back direction (Y-axis direction in Figure 10).

[0096] (3.5) Modification 5 In the multilayer varistor 1D of the above modified example 4, the portion of the first internal electrode 3D in the third direction (Z-axis direction in Figure 10) where the thickness of the first lead portion 32D is smaller than the thickness of the first opposing portion 31 may be a recessed portion in the third direction. Similarly, the portion of the second internal electrode 4D in the third direction (Z-axis direction in Figure 10) where the thickness of the second lead portion 42D is smaller than the thickness of the second opposing portion 41 may be a recessed portion in the third direction.

[0097] Figure 11 is a cross-sectional view of a stacked varistor 1E according to a modified example 5 of one embodiment of the present disclosure. As shown in Figure 11, the first lead portion 32E of the first internal electrode 3E is formed in a wavy shape in cross-sectional view. More specifically, the first lead portion 32E of the first internal electrode 3E has second recesses 10 on its upper and lower surfaces, respectively. Two second recesses 10 are provided on the upper surface of the first lead portion 32E, spaced apart in the second direction (the X-axis direction in Figure 11). The two second recesses 10 provided on the upper surface of the first lead portion 32E are V-shaped in cross-sectional view and recessed downward (the negative Z-axis direction in Figure 11). Two second recesses 10 are provided on the lower surface of the first lead portion 32E, spaced apart in the second direction (the X-axis direction in Figure 11). The two second recesses 10 provided on the lower surface of the first pull-out section 32E are V-shaped in cross-section and are recessed upward (in the positive direction of the Z-axis in Figure 11).

[0098] Furthermore, as shown in Figure 11, the second lead portion 42E of the second internal electrode 4E is formed in a wavy shape in cross-sectional view. More specifically, the second lead portion 42E of the second internal electrode 4E has second recesses 10 on its upper and lower surfaces. Two second recesses 10 are provided on the upper surface of the second lead portion 42E, spaced apart in the second direction (the X-axis direction in Figure 11). The two second recesses 10 on the upper surface of the second lead portion 42E are V-shaped grooves in cross-sectional view. The V-shaped grooves are recessed downwards (the negative direction of the Z-axis direction in Figure 11). Two second recesses 10 are provided on the lower surface of the second lead portion 42E, spaced apart in the second direction (the X-axis direction in Figure 11). The two second recesses 10 on the lower surface of the second lead portion 42E are V-shaped grooves in cross-sectional view. The V-shaped groove is concave upwards (in the positive direction of the Z-axis in Figure 11).

[0099] In the modified example 5, the laminated varistor 1E, as shown in Figure 11, has multiple second recesses 10 in the first internal electrode 3E that are recessed in a V-shape in the second direction (X-axis direction in Figure 11) of the first drawout portion 32E. As a result, the first drawout portion 32E has less strength in the third direction (Z-axis direction in Figure 10) than the first opposing portion 31. Consequently, if a crack occurs inside the sintered body 2, a part of the first drawout portion 32E is more likely to break than the first opposing portion 31. When a part of the first drawout portion 32E breaks due to a crack, the crack is less likely to propagate from the first drawout portion 32E to the first opposing portion 31.

[0100] Furthermore, according to the laminated varistor 1E of the modified example 5, as shown in Figure 11, in the second internal electrode 4E, the multiple second recesses 10 provided in the second direction (X-axis direction in Figure 11) of the second extraction portion 42E are recessed in a V-shape, so the strength of the second extraction portion 42E in the third direction (Z-axis direction in Figure 11) is weaker than that of the second opposing portion 41. As a result, if a crack occurs inside the sintered body 2, a part of the second extraction portion 42E is more likely to break than the second opposing portion 41. If a part of the second extraction portion 42E breaks due to a crack, the crack is less likely to propagate from the second extraction portion 42E to the second opposing portion 41.

[0101] Therefore, according to the multilayer varistor 1E of modified example 5, cracks are less likely to occur spanning between the first internal electrode 3 and the second internal electrode 4, thus suppressing the occurrence of short-circuit failures.

[0102] In the cross-sectional view of Figure 11, the first lead portion 32E of the first internal electrode 3E electrically connects the first opposing portion 31 and the first external electrode G1 via multiple portions with reduced thickness in the second direction (the X-axis direction in Figure 11). Similarly, the second lead portion 42E of the second internal electrode 4E electrically connects the second opposing portion 41 and the second external electrode G2 via multiple portions with reduced thickness in the second direction (the X-axis direction in Figure 11). Multiple portions with reduced thickness may be formed in a matrix on the upper or lower surface of the first lead portion 32E of the first internal electrode 3E. Likewise, multiple portions with reduced thickness may be formed in a matrix on the upper or lower surface of the second lead portion 42E of the second internal electrode 4E. This makes the first lead portion 32E and the second lead portion 42E more susceptible to fracture in the planar direction (the direction parallel to the XY plane in Figure 11).

[0103] (3.6) Modification 6 In the multilayer varistor 1 of the above embodiment, one first internal electrode 3 (first opposing portion 31) faces one second internal electrode 4 (second opposing portion 41) in the third direction (Z-axis direction in Figure 5) (see Figure 5). In contrast, multiple first internal electrodes 3 may be provided in the third direction, and multiple second internal electrodes 4 may be provided in the third direction.

[0104] Figure 12 is a cross-sectional view of a laminated varistor 1F according to Modification 6 of one embodiment of the present disclosure. As shown in Figure 12, in the laminated varistor 1F according to Modification 6, multiple (five in Figure 12) first internal electrodes 3 are provided in the third direction (Z-axis direction in Figure 12). Multiple (four in Figure 12) second internal electrodes 4 are provided in the third direction (Z-axis direction in Figure 12). More specifically, the five first internal electrodes 3 are provided on different laminated surfaces (not shown) in the third direction (Z-axis direction in Figure 12). Also, the four second internal electrodes 4 are provided on different laminated surfaces (not shown) in the third direction (Z-axis direction in Figure 12). Each of the five first internal electrodes 3 and each of the four second internal electrodes 4 are arranged alternately in the third direction.

[0105] The multilayer varistor 1F is mounted on a substrate (not shown) with, for example, the second main surface S32 of the sintered body 2 facing the substrate (see Figure 12). In this case, the substrate flexes, causing stress to be applied upward (in the positive Z-axis direction in Figure 12) from the substrate to the sintered body 2.

[0106] As shown in Figure 12, when the substrate is subjected to excessive stress, a crack CK1 is generated inside the sintered body 2. In Figure 12, the crack CK1 is generated on the surface of the second main surface S32 of the sintered body 2 near the second external electrode G2 and propagates upward and to the right inside the sintered body 2. The crack CK1 propagates inside the sintered body 2, crossing the two second internal electrode 4's pull-out portions 42 and fracturing parts of the pull-out portions 42 of the two lower second internal electrodes 4, and eventually reaches the second end surface S12 of the sintered body 2.

[0107] In the laminated varistor 1F shown in Figure 12, two second internal electrodes 4 that are partially fractured by crack CK1 may be disconnected. However, since there are five second internal electrodes 4, even if two second internal electrodes 4 are disconnected, the laminated varistor 1F as a whole can maintain its function as long as the remaining three second internal electrodes 4 remain connected.

[0108] Furthermore, Figure 12 shows a case in the multilayer varistor 1F where some of the multiple second internal electrodes 4 are disconnected due to a crack CK1. However, even if some of the multiple first internal electrodes 3 are disconnected, the multilayer varistor 1F as a whole can maintain its function as long as the remaining first internal electrodes 3 are functioning.

[0109] In Figure 12, the crack CK1 spans the two lead-out portions 42 of the second internal electrodes 4 inside the sintered body 2. However, even if the two lead-out portions 42 of the second internal electrodes 4 short-circuit, it will not affect the function of the laminated varistor 1F.

[0110] In addition, in the multilayer varistors 1A to 1E of the above modified examples 1 to 5, one first internal electrode 3 (first opposing portion 31) faces one second internal electrode 4 (second opposing portion 41) in the third direction (Z-axis direction in Figure 5). However, multiple first internal electrodes 3 may be provided in the third direction, and multiple second internal electrodes 4 may be provided in the third direction.

[0111] (3.7) Other variations In the above embodiment and the above modifications 1 to 6, one varistor element is formed in the stacked varistor, but multiple varistor elements may be formed. For example, in the above embodiment, in order to form multiple varistor elements, a third internal electrode, which is a common electrode for grounding, is formed between the first internal electrode 3 and the second internal electrode 4 in the stacking direction (Z-axis direction in Figure 5). This makes it possible to form a first varistor element between the first internal electrode 3 and the third internal electrode, and a second varistor element between the second internal electrode 4 and the third internal electrode.

[0112] Furthermore, while the above embodiments and modifications 1 to 6 describe chip-type multilayer varistors, chip-type multilayer capacitors or multilayer thermistors may also be used. In short, any multilayer electronic component formed by stacking ceramics will suffice.

[0113] (summary) Based on the embodiments described above, the following aspects are disclosed.

[0114] The first embodiment of the multilayer electronic component (1) comprises a sintered body (2), a first internal electrode (3), and a second internal electrode (4). The sintered body (2) has a multilayer structure in which a plurality of layers (LY1, LY2, LY3) are stacked on a plurality of stacking surfaces (SF1, SF2). The plurality of stacking surfaces include at least a first stacking surface (SF1) and a second stacking surface (SF2). The first internal electrode (3) is provided on the first stacking surface (SF1). The second internal electrode (4) is provided on the second stacking surface (SF2). The first internal electrode (3) has a first opposing portion (31) that faces the second internal electrode (4) in the stacking direction, and a first lead portion (32) that connects the first opposing portion (31) and the first external electrode (G1). The second internal electrode (4) has a second opposing portion (41) that faces the first internal electrode (3) in the stacking direction, and a second leading portion (42) that connects the second opposing portion (41) and the second external electrode (G2). At least one of the leading portions, the first leading portion (32) and the second leading portion (42), is weaker in strength than either the first opposing portion (31) or the second opposing portion (41).

[0115] According to this embodiment, if a crack (CK1) occurs inside the sintered body (2), a portion of the drawn-out portions (32, 42) of the internal electrodes (3, 4) becomes more prone to fracture than the opposing portions (31, 41). When a portion of the drawn-out portions (32, 42) fractures due to the crack (CK1), the crack (CK1) becomes less likely to propagate from the drawn-out portions (32, 42) to the opposing portions (31, 41). As a result, the crack (CK1) becomes less likely to occur spanning between the first internal electrode (3) and the second internal electrode (4). This makes it possible to suppress the occurrence of short-circuit defects.

[0116] In the second embodiment of the stacked electronic component (1), in the first embodiment, at least one of the first lead portion (32) and the second lead portion (42) is provided with an opening (7) that penetrates in the stacking direction.

[0117] In this embodiment, the openings (7) provided in the draw-out sections (32, 42) result in weaker planar strength compared to the opposing sections (31, 41). As a result, if a crack (CK1) occurs inside the sintered body (2), a portion of the draw-out sections (32, 42) is more prone to fracture than the opposing sections (31, 41).

[0118] In the third embodiment of the stacked electronic component (1), in the first embodiment, at least one of the first lead-out portion (32) and the second lead-out portion (42) is provided with a plurality of comb teeth (8) in a plan view.

[0119] In this embodiment, since the draw-out sections (32, 42) are provided with multiple comb teeth (8) in a plan view, their strength in the planar direction is weaker than that of the opposing sections (31, 41). As a result, if a crack (CK1) occurs inside the sintered body (2), a part of the draw-out sections (32, 42) is more likely to break than the opposing sections (31, 41).

[0120] In the fourth embodiment of the multilayer electronic component (1), in any one of the first to third embodiments, the first lead portion (32) extends toward the first external electrode (G1), and the second lead portion (42) extends toward the second external electrode (G2). A first recess (9) is provided in at least one of the lead portions of the first lead portion (32) and the second lead portion (42). In a plan view, the first recess (9) is recessed in a direction intersecting the direction toward the first external electrode (G1) or the second external electrode (G2).

[0121] In this embodiment, since the first recess (9) provided in the draw-out portion (32, 42) is recessed in the planar direction, its strength in the planar direction is weaker than that of the opposing portion (31, 41). As a result, if a crack (CK1) occurs inside the sintered body (2), a part of the draw-out portion (32, 42) is more likely to break than the opposing portion (31, 41).

[0122] The stacked electronic component (1) of the fifth embodiment, in any one of the first to fourth embodiments, has a portion of the first lead portion (32) and the second lead portion (42) whose thickness in the stacking direction is smaller than the thickness of the first opposing portion (31) or the second opposing portion (41) in the stacking direction.

[0123] According to this embodiment, since the thickness of the draw-out portion (32, 42) in the stacking direction is smaller than the thickness of the opposing portion (31, 41) in the stacking direction, the draw-out portion (32, 42) has weaker strength in the stacking direction than the opposing portion (31, 41). As a result, if a crack (CK1) occurs inside the sintered body (2), a part of the draw-out portion (32, 42) is more likely to break than the opposing portion (31, 41).

[0124] In the sixth embodiment of the stacked electronic component (1), the portion with less thickness is a second recess (10) provided in at least one of the first lead portion (32) and the second lead portion (42). The second recess (10) is recessed in the stacking direction.

[0125] In this embodiment, since the second recess (10) provided in the draw-out portions (32, 42) is recessed in the stacking direction, the draw-out portions (32, 42) have weaker strength in the stacking direction than the opposing portions (31, 41). As a result, if a crack (CK1) occurs inside the sintered body (2), a part of the draw-out portions (32, 42) is more likely to break than the opposing portions (31, 41).

[0126] In the seventh embodiment, the stacked electronic component (1) has a cross-sectional shape of the second recess (10) that is a V-shaped groove.

[0127] In this embodiment, since the cross-sectional shape of the second recess (10) provided in the draw-out portion (32, 42) is a V-shaped groove, the strength of the draw-out portion (32, 42) is weakened. As a result, if a crack (CK1) occurs inside the sintered body (2), it becomes more prone to fracture.

[0128] In the eighth embodiment of the stacked electronic component (1), in any one of the first to seventh embodiments, a plurality of first internal electrodes (3) are provided in the stacking direction. A plurality of second internal electrodes (4) are provided in the stacking direction. Each of the plurality of first internal electrodes (3) and each of the plurality of second internal electrodes (4) are arranged alternately in the stacking direction.

[0129] According to this embodiment, although cracks (CK1) occurring inside the sintered body (2) may cause the internal electrodes (3, 4) to break, since multiple internal electrodes (3, 4) are provided, even if some of the multiple internal electrodes (3, 4) break, the multilayer electronic component (1) as a whole can maintain its function.

[0130] The multilayer electronic component (1) of the ninth embodiment further comprises a first external electrode (G1) and a second external electrode (G2) in any one of the first to eighth embodiments. The first external electrode (G1) is electrically connected to a first internal electrode (3). The second external electrode (G2) is electrically connected to a second internal electrode (4). The sintered body (2) has a first end face (S11) and a second end face (S12), a first side surface (S21) and a second side surface (S22), and a first main surface (S31) and a second main surface (S32). The sintered body (2) is formed in the shape of a rectangular parallelepiped. The first end face (S11) and the second end face (S12) face each other in a first direction. The first side surface (S21) and the second side surface (S22) face each other in a second direction intersecting the first direction. The first main surface (S31) and the second main surface (S32) face each other in the first direction and in a third direction intersecting the second direction. The stacking direction is the third direction. The first external electrode (G1) is provided on the first end surface (S11). The second external electrode (G2) is provided on the second end surface (S12).

[0131] In the tenth embodiment of the stacked electronic component (1), a varistor element is formed between the first opposing portion (31) of the first internal electrode (3) and the second opposing portion (41) of the second internal electrode (4) in any one of the first to ninth embodiments.

[0132] According to this embodiment, it is possible to suppress the occurrence of short-circuit failures in the stacked varistor (1).

[0133] The configurations relating to the second to tenth aspects are not essential to the stacked electronic component (1) and can be omitted as appropriate. [Explanation of symbols]

[0134] 1. 1A~1F Multilayer varistor (multilayer electronic component) 2 Sintered body 3 1st internal electrode 4 Second internal electrode 7 Opening 8 comb teeth 9. First recess 10. Second recess 31 First Opposite Section 32 1st drawer 41 Second opposing section 42 2nd drawer G1 1st external electrode G2 2nd external electrode LY1 1st layer LY2 2nd layer LY3 3rd layer S11 1st end surface S12 2nd end face S21 1st side S22 2nd side S31 First Main Surface S32 Second Main Surface SF1 1st laminated surface SF2 2nd laminated surface CK1 Crack

Claims

1. A sintered body having a laminated structure in which multiple layers are stacked on multiple stacking surfaces, The plurality of laminated surfaces include at least a first laminated surface and a second laminated surface, The first internal electrode provided on the first laminated surface, The second internal electrode is provided on the second laminated surface, The first internal electrode has a first opposing portion that faces the second internal electrode in the stacking direction, and a first leading portion that connects the first opposing portion and the first external electrode. The second internal electrode has a second opposing portion that faces the first internal electrode in the stacking direction, and a second leading portion that connects the second opposing portion and the second external electrode. At least one of the first and second drawer sections is weaker in strength than the first opposing section or the second opposing section. Multilayer electronic components.

2. At least one of the first and second drawer sections is provided with an opening that penetrates in the stacking direction. The multilayer electronic component according to claim 1.

3. In plan view, at least one of the first and second drawer sections is provided with a plurality of comb teeth. The multilayer electronic component according to claim 1.

4. The first lead portion extends toward the first external electrode, and The second lead portion extends toward the second external electrode, A first recess is provided in at least one of the first and second drawer sections. The first recess is recessed in a direction intersecting the direction toward the first external electrode or the second external electrode when viewed from above. The multilayer electronic component according to claim 1.

5. At least one of the first and second drawer portions has a portion whose thickness in the stacking direction is smaller than the thickness of the first or second opposing portion in the stacking direction. The multilayer electronic component according to claim 1.

6. The portion with reduced thickness is a second recess provided in at least one of the first and second drawer portions. The second recess is recessed in the stacking direction. The multilayer electronic component according to claim 5.

7. The cross-sectional shape of the second recess is a V-shaped groove. The multilayer electronic component according to claim 6.

8. The first internal electrode is provided in multiple locations in the stacking direction, The second internal electrode is provided in multiple locations in the stacking direction, Each of the plurality of first internal electrodes and each of the plurality of second internal electrodes are arranged alternately in the stacking direction. A multilayer electronic component according to any one of claims 1 to 7.

9. The first external electrode is electrically connected to the first internal electrode, The system further comprises a second external electrode electrically connected to the second internal electrode, The sintered body has a first end face and a second end face that face each other in a first direction, a first side surface and a second side surface that face each other in a second direction intersecting the first direction, and a first main surface and a second main surface that face each other in a third direction intersecting the first and second directions, and is formed in the shape of a rectangular parallelepiped. The aforementioned stacking direction is the third direction, The first external electrode is provided on the first end face, The second external electrode is provided on the second end face, A multilayer electronic component according to any one of claims 1 to 7.

10. A varistor element is formed between the first opposing portion of the first internal electrode and the second opposing portion of the second internal electrode. A multilayer electronic component according to any one of claims 1 to 7.

Images