Multilayer capacitor

Abstract

The invention relates to a multilayer capacitor. In an element body of a multilayer capacitor (C1), a plurality of dielectric layers and a plurality of internal electrode layers extend in first and second directions that are orthogonal to each other, and the plurality of dielectric layers and the plurality of internal electrode layers are alternately stacked in a third direction that intersects the first and second directions. The element body comprises at least one end face. On at least one end face, at least one internal electrode of the plurality of internal electrode layers is exposed from the plurality of dielectric layers. The external electrode terminal is provided on the at least one end surface. The external electrode terminal is connected to the at least one internal electrode layer. In the element body, the weight ratio of the metal containing Ni is 20-25%, and the weight ratio of sulfur is 3-20 ppm.

Description

Technical Field

[0001] The present invention relates to a stacked capacitor. Background Art

[0002] A multilayer capacitor having an element body and an external electrode terminal provided on the element body is known (for example, Japanese Patent Publication No. 2003-218060). In the element body of the multilayer capacitor, a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked. The plurality of internal electrode layers are exposed from the plurality of dielectric layers on the end surface of the element body. The external electrode terminal is connected to at least one of the internal electrode layers. Summary of the invention

[0003] In the above-mentioned multilayer capacitor, the multilayer capacitor functions by connecting the external electrode terminal and the internal electrode layer, and the electrical characteristics of the multilayer capacitor are ensured. Therefore, it is sought to improve the connection reliability between the external electrode terminal and the internal electrode layer. It is believed that if the plurality of internal electrode layers are configured to protrude from the plurality of dielectric layers on the above-mentioned end surface, the connection reliability between the external electrode terminal and the internal electrode layer is improved.

[0004] In addition, in the above-mentioned multilayer capacitor, it is also sought to suppress the generation of cracks in the element body. If cracks are generated, water may penetrate into the inside of the element body, and the internal electrodes may be disconnected and short-circuited. Therefore, for example, chip components with cracks on the element body are excluded during manufacturing. As long as the generation of cracks is suppressed during manufacturing, production capacity will be improved.

[0005] An object of one aspect of the present invention is to provide a multilayer capacitor having a structure that suppresses the occurrence of cracks in an element body, ensures desired electrical characteristics, and improves the connection reliability between external electrode terminals and internal electrode layers.

[0006] A multilayer capacitor according to one aspect of the present invention comprises a body and an external electrode terminal. In the body, a plurality of dielectric layers and a plurality of internal electrode layers extend in first and second directions orthogonal to each other, and a plurality of dielectric layers and a plurality of internal electrode layers are alternately stacked in a third direction intersecting the first and second directions. The body comprises at least one end face. On at least one end face, at least one internal electrode of a plurality of internal electrode layers is exposed from a plurality of dielectric layers. An external electrode terminal is disposed on the at least one end face. The external electrode terminal is connected to the at least one internal electrode layer. In the body, the weight ratio of the metal containing Ni is 20% to 25%, and the weight ratio of sulfur is 3ppm to 20ppm.

[0007] The inventors of the present application have conducted in-depth research and found that the generation of cracks in the element body, the connection reliability between the external electrode terminals and the internal electrode layers, and the desired electrical characteristics depend on the content ratio of the above-mentioned metal and sulfur in the element body. According to the research results of the inventors of the present application, when there is too little sulfur in the element body, the multiple internal electrode layers may not protrude from the multiple dielectric layers on the above-mentioned end faces. When there is too much sulfur in the element body, cracks may occur in the element body. When there is too much metal, cracks may also occur in the element body. When there is too little metal, it is difficult to ensure the capacitance per unit volume. In contrast, according to further research by the inventors of the present application, only when the content ratio of the above-mentioned metal and sulfur in the element body is within the above-mentioned range, the generation of cracks in the element body can be suppressed, the desired electrical characteristics can be ensured, and the connection reliability of the external electrode terminals and the internal electrode layers can be improved. Therefore, the manufacturing capacity can be improved.

[0008] In the above aspect, when the end face is viewed from a direction perpendicular to the end face, the ratio of the area occupied by the plurality of internal electrode layers to the area of ​​the end face may be 5% to 12%. In this case, it is easy to achieve a balance in the content of sulfur contained in the internal electrode layers. Therefore, the manufacturing capacity can be improved.

[0009] In the above aspect, in each of the plurality of internal electrode layers, when the end face is viewed from a direction perpendicular to the end face, the value obtained by dividing the area of ​​the internal electrode layer exposed from the plurality of dielectric layers by the volume of the internal electrode layer may be 0.15 to 0.40. In this case, it is easy to achieve a balance in the sulfur content in the element body. Therefore, the manufacturing capacity can be improved.

[0010] In the above aspect, at least one end face may include a pair of end faces. In a pair of end faces, different internal electrode layers among a plurality of internal electrode layers are exposed. A plurality of internal electrode layers may include a pair of internal electrode layers. A pair of internal electrode layers are adjacent to each other. A pair of internal electrode layers are exposed at different end faces among a pair of end faces. A pair of internal electrodes may also include overlapping portions that overlap each other, and lead portions that are connected to the overlapping portions and exposed at the end faces. When the width of the lead portion in the second direction is "W1" and the width of the overlapping portion in the second direction is "W2", 1-(W1 / W2) may also be 0.35 to 0.55. In this case, it is easy to reduce the sulfur content in the element body and to ensure the thickness of the external electrode terminal. Therefore, the manufacturing capacity can be improved, and the intrusion of liquid into the internal electrode layer can be suppressed.

[0011] In the above aspect, the plurality of dielectric layers may form a pair of outer layer portions, the pair of outer layer portions being located at a position further outward than the plurality of internal electrode layers in the third direction and being positioned so as to sandwich the plurality of internal electrode layers. The thickness of one of the pair of outer layer portions may also be 5% to 10% of the thickness of the entire element body in the third direction. In this case, it is easy to reduce the sulfur content in the element body and to ensure the thickness of the external electrode terminal. Therefore, the manufacturing capacity can be improved, and the intrusion of liquid into the internal electrode layer can be suppressed.

[0012] The present invention will be more fully understood from the following detailed description and accompanying drawings, which are given by way of illustration only and should not be construed as limiting the present invention.

[0013] The further applicability of the present invention will become apparent through the following detailed description. However, it should be understood that the detailed description and specific examples show preferred embodiments of the present invention and are given by way of illustration only, because, based on the detailed description, various variations and modifications within the spirit and scope of the present invention will become apparent to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of the multilayer capacitor according to the present embodiment.

[0015] Figure 2 It is a partial cross-sectional view of a multilayer capacitor.

[0016] Figure 3 This is an end view of an element body in a multilayer capacitor.

[0017] Figure 4 It is a cross-sectional view of the element body observed from the lead-out direction of the lead-out portion.

[0018] Figure 5 This is a cross-sectional view of the element body viewed from the stacking direction.

[0019] Figure 6 This is a graph for explaining the set temperature for firing.

[0020] Figure 7 This is an enlarged view of the element body in the lead-out part.

[0021] Figure 8 This is a graph showing the relationship between the sulfur content and the protrusion length.

[0022] Fig. 9 It is a figure for demonstrating the measurement of the protrusion amount.

[0023] Fig.10 This is a graph showing the relationship between sulfur content, capacitance, and thermal cracking of a device.

[0024] Fig.11 The figures show various embodiments and comparative examples.

[0025] Explanation of symbols:

[0026] 3…body, 3e…end face, 5…external electrode terminal, 12…dielectric layer, 12A, 12B…outer layer, 13, 15…internal electrode layer, 13b, 15b…lead-out portion, 15c…overlapping portion, C1…stacked capacitor, D1…first direction, D2…second direction, D3…third direction, Rs…range, W1, W2…width. DETAILED DESCRIPTION

[0027] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same reference numerals are used for the same or equivalent elements, and repeated descriptions are omitted.

[0028] First, refer to Figure 1 to Figure 7 The structure of the multilayer capacitor of this embodiment will be described. The multilayer capacitor C1 is, for example, a multilayer ceramic capacitor. Figure 1 It is a perspective view of the multilayer capacitor according to the present embodiment. Figure 2 It is a partial cross-sectional view of a multilayer capacitor.

[0029] like Figure 1 and Figure 2 As shown, the multilayer capacitor C1 includes a rectangular parallelepiped element body 3 and a plurality of external electrode terminals 5. In the present embodiment, the multilayer capacitor C1 includes a pair of external electrode terminals 5. The pair of external electrode terminals 5 are arranged on the outer surface of the element body 3. The pair of external electrode terminals 5 are separated from each other. The rectangular parallelepiped shape includes a rectangular parallelepiped shape with chamfered corners and ridges, and a rectangular parallelepiped shape with rounded corners and ridges.

[0030] The element body 3 has a pair of side faces 3a facing each other, a pair of side faces 3c facing each other, and a pair of end faces 3e facing each other. The pair of side faces 3a, the pair of side faces 3c, and the pair of end faces 3e are rectangular. The direction in which the pair of side faces 3a face each other is the third direction D3. The direction in which the pair of side faces 3c face each other is the second direction D2. The direction in which the pair of end faces 3e face each other is the first direction D1. The first direction D1 and the second direction D2 are orthogonal to each other. The third direction D3 intersects the first direction D1 and the second direction D2.

[0031] The stacked capacitor C1 is soldered and mounted on an electronic device. The electronic device includes, for example, a circuit substrate or a stacked capacitor. In the stacked capacitor C1, one side 3a is opposite to the electronic device. One side 3a is configured to constitute a mounting surface. One side 3a is a mounting surface. One side 3c of a pair of side surfaces 3c may also be configured to constitute a mounting surface. For example, when the side surface 3a constitutes the first side surface, the side surface 3c constitutes the second side surface.

[0032] The third direction D3 is a direction orthogonal to each side surface 3a, and is orthogonal to the second direction D2. The first direction D1 is a direction parallel to each side surface 3a and each side surface 3c, and is orthogonal to the second direction D2 and the third direction D3. The second direction D2 is a direction orthogonal to each side surface 3c, and the first direction D1 is a direction orthogonal to each end surface 3e. In the present embodiment, the length of the element body 3 in the first direction D1 is greater than the length of the element body 3 in the second direction D2, and is greater than the length of the element body 3 in the third direction D3. The first direction D1 is the long side direction of the element body 3. The length of the element body 3 in the second direction D2 and the length of the element body 3 in the third direction D3 may also be equal to each other. The length of the element body 3 in the first direction D1 and the length of the element body 3 in the third direction D3 may also be different from each other. In the example shown in the present embodiment, the first direction D1 is equivalent to the Y-axis direction, the second direction D2 is equivalent to the X-axis direction, and the third direction D3 is equivalent to the Z-axis direction.

[0033] The length of the element body 3 in the third direction D3 is the height of the element body 3. The length of the element body 3 in the second direction D2 is the width of the element body 3. The length of the element body 3 in the first direction D1 is the length of the element body 3. In this embodiment, the height T of the element body 3 is 0.27 to 2.90 mm, the width W of the element body 3 is 0.27 to 2.90 mm, and the length L of the element body 3 is 0.57 to 3.60 mm. For example, the height T of the element body 3 is 1.84 mm, the width W of the element body 3 is 1.83 mm, and the length L of the element body 3 is 3.35 mm.

[0034] The pair of side surfaces 3c extend in the third direction D3 so as to connect the pair of side surfaces 3a. The pair of side surfaces 3c also extend in the first direction D1. The pair of end surfaces 3e extend in the third direction D3 so as to connect the pair of side surfaces 3a. The pair of end surfaces 3e also extend in the second direction D2.

[0035] The element body 3 has four ridges 3g, four ridges 3i, and four ridges 3j. The ridge 3g is located between the end face 3e and the side face 3a. The ridge 3i is located between the end face 3e and the side face 3c. The ridge 3j is located between the side face 3a and the side face 3c. In the present embodiment, each of the ridges 3g, 3i, and 3j is rounded in a curved manner. The element body 3 is subjected to a so-called R chamfering process. The end face 3e and the side face 3a are indirectly adjacent via the ridge 3g. The end face 3e and the side face 3c are indirectly adjacent via the ridge 3i. The side face 3a and the side face 3c are indirectly adjacent via the ridge 3j.

[0036] The element body 3 includes a plurality of dielectric layers 12, a plurality of internal electrode layers 13, and a plurality of internal electrode layers 15. In the element body 3, the plurality of dielectric layers 12, the plurality of internal electrode layers 13, and the plurality of internal electrode layers 15 are alternately stacked in the third direction D3. In other words, the stacking direction of the plurality of dielectric layers 12 and the stacking direction of the plurality of internal electrode layers 13 and 15 are consistent with the third direction D3. The plurality of dielectric layers 12, the plurality of internal electrode layers 13, and the plurality of internal electrode layers 15 extend along the first direction D1 and the second direction D2.

[0037] Each dielectric layer 12 includes an oxide ceramic. Each dielectric layer 12 is composed of, for example, a sintered body of a ceramic green sheet containing a dielectric material. The dielectric material includes, for example, a dielectric ceramic of a BaTiO3 system, a Ba(Ti,Zr)O3 system, or a (Ba,Ca)TiO3 system. In the actual element body 3, each dielectric layer is integrated to the extent that the boundaries between the dielectric layers are not recognizable.

[0038] Each internal electrode layer 13, 15 is an internal conductor arranged in the element body 3. The plurality of internal electrode layers 13, 15 are opposed to each other in the third direction D3. The plurality of internal electrode layers 13 are located closer to one of the pair of end faces 3e than the plurality of internal electrode layers 15. The plurality of internal electrode layers 15 are located closer to the other of the pair of end faces 3e than the plurality of internal electrode layers 13.

[0039] At least one end of the plurality of internal electrode layers 13 is exposed from the corresponding end surface 3e. At least one end of the plurality of internal electrode layers 15 is exposed from the corresponding end surface 3e. The plurality of internal electrode layers 13 and 15 have one end exposed from the corresponding end surface 3e. The plurality of internal electrode layers 13 and 15 are connected to the corresponding external electrode terminal 5 at the portion exposed from the end surface 3e. Figure 2 and Figure 3 As an example, a state in which a plurality of internal electrode layers 15 are exposed from the end surface 3 e is shown. Figure 3 FIG. 1 is an end view of the element body 3 in the multilayer capacitor C1.

[0040] When the end face 3e is viewed from the first direction D1 perpendicular to the end face 3e, the ratio of the area occupied by the plurality of internal electrode layers 15 to the area of ​​the end face 3e is 5% to 12%. Similarly, when the end face 3e is viewed from the first direction D1 perpendicular to the end face 3e, the ratio of the area occupied by the plurality of internal electrode layers 13 to the area of ​​the end face 3e is 5% to 12%.

[0041] The plurality of internal electrode layers 13, 15 include a pair of internal electrode layers 13, 15 adjacent to each other and exposed at different end faces 3e of a pair of end faces 3e. Figure 3 to Figure 5 As shown, the pair of internal electrode layers 13, 15 include lead portions 15b and overlapping portions 15c, respectively. Figure 4 It is a cross-sectional view of the element body 3 along the stacking direction as viewed from the first direction D1. Figure 5 It is a cross-sectional view of the element body 3 along the first direction D1 and the second direction D2 as viewed from the stacking direction.

[0042] The overlapping portion 15c is a portion that overlaps each other in a pair of internal electrode layers 13 and 15. The lead portion 15b is a portion that is connected to the overlapping portion 15c in each internal electrode layer 13 and 15. The lead portion 15b extends from the overlapping portion 15c in the first direction D1 and is exposed at the end surface 3e. When the width of the lead portion 15b in the second direction D2 is "W1" and the width of the overlapping portion 15c in the second direction D2 is "W2", 1-(W1 / W2) is 0.35 to 0.55. 1-(W1 / W2) can be expressed as an elongation in percentage. When the above conditions are met, the elongation is 35% to 55%.

[0043] In each of the plurality of internal electrode layers 15, when the end face 3e is viewed from a direction perpendicular to the end face 3e, the value obtained by dividing the area of ​​the internal electrode layer 15 exposed from the plurality of dielectric layers 12 by the volume of the internal electrode layer 15 is 0.15 to 0.4. Similarly, in each of the plurality of internal electrode layers 13, when the end face 3e is viewed from a direction perpendicular to the end face 3e, the value obtained by dividing the area of ​​the internal electrode layer 13 exposed from the plurality of dielectric layers 12 by the volume of the internal electrode layer 13 is 0.15 to 0.4.

[0044] The area of ​​the internal electrode layers 13 and 15 exposed from the plurality of dielectric layers 12 is calculated, for example, based on the product of the width W1 of the lead portion 15b in the second direction D2 and the thickness of the lead portion 15b in the third direction D3. The volume of the internal electrode layers 13 and 15 is the sum of the volume of the lead portion 15b and the volume of the overlapping portion 15c. The volume of the lead portion 15b is calculated, for example, based on the product of the width W1 of the lead portion 15b in the second direction D2, the width of the lead portion 15b in the first direction, and the thickness of the lead portion 15b. The volume of the overlapping portion 15c is calculated, for example, based on the product of the width W2 of the overlapping portion 15c in the second direction D2, the width of the overlapping portion 15c in the first direction D1, and the thickness of the overlapping portion 15c.

[0045] Each internal electrode layer 13, 15 is made of a conductive material generally used as an internal conductor of a laminated electronic component. The conductive material includes, for example, a base metal. The conductive material includes, for example, Ni or Cu. The internal electrode layers 13, 15 are formed as a sintered body of a conductive paste containing the above conductive material. In the present embodiment, the internal electrode layers 13, 15 are made of Ni. The weight ratio of the metal containing Ni in the element body 3 is 20% to 25%. The weight ratio of sulfur in the element body 3 is 3 ppm to 20 ppm.

[0046] For example, the sulfur content in the element body 3 changes according to the temperature setting of the debinding process performed before the firing process of the element body 3. In the debinding process, the organic binders, organic solvents, etc. contained in the dielectric layer 12 and the internal electrode layers 13 and 15 before firing are removed from the element body 3. In the debinding process, the element body 3 placed on the carrier is arranged in a furnace, and heated in the furnace for 1 hour to 20 hours in a state where the set debinding temperature is kept constant. The carrier, for example, includes a vent that passes from the front side to the back side of the element body 3 before firing. Through the debinding process, the organic binder and organic solvent in the element body 3 are gasified or decomposed to be gasified. Figure 6 An example of a distribution diagram of temperature setting and time in the binder removal process is shown. In this case, in the binder removal process, the temperature setting includes a range Rs maintained at 1000 degrees.

[0047] The internal electrode layers 13 and the internal electrode layers 15 are arranged at different positions (layers) in the third direction D3. The internal electrode layers 13 and the internal electrode layers 15 are alternately arranged in the element body 3 so as to face each other with a gap in the third direction D3. The internal electrode layers 13 and the internal electrode layers 15 have different polarities. One end of the internal electrode layers 13 and 15 is exposed on the corresponding end surface 3e. The internal electrode layers 13 and 15 have one end exposed on the corresponding end surface 3e.

[0048] The plurality of internal electrode layers 13 and the plurality of internal electrode layers 15 are alternately arranged in the third direction D3. Each of the internal electrode layers 13 and 15 is located in a plane substantially parallel to the side surface 3a. Each of the internal electrode layers 13 and 15 extends in the first direction D1 and the second direction D2. The internal electrode layers 13 and the internal electrode layers 15 are opposite to each other in the third direction D3. The third direction D3 in which the internal electrode layers 13 and the internal electrode layers 15 are opposite is orthogonal to the first direction D1 and the second direction D2 parallel to the side surface 3a. The direction parallel to the side surface 3a is equivalent to the first direction D1 and the second direction D2.

[0049] like Figure 3 and Figure 4 As shown, the plurality of internal electrode layers 13 include an outermost internal electrode layer 13A located at the outermost side in the third direction D3. The outermost internal electrode layer 13A is opposite to one side 3a of the pair of side surfaces 3a in the third direction D3. The plurality of internal electrode layers 15 include an outermost internal electrode layer 15A located at the outermost side in the third direction D3. The outermost internal electrode layer 15A is opposite to the other side 3a of the pair of side surfaces 3a in the third direction D3.

[0050] The plurality of dielectric layers 12 form a pair of outer layer portions 12A, 12B, which are located outside the plurality of internal electrode layers 13, 15 in the third direction D3 and are positioned so as to sandwich the plurality of internal electrode layers 13, 15. The pair of outer layer portions 12A, 12B are located outside the outermost internal electrode layers 13A, 15A in the third direction D3. The pair of outer layer portions 12A, 12B are positioned so as to sandwich the plurality of internal electrode layers 13, 15 including the outermost internal electrode layers 13A, 15A. The pair of outer layer portions 12A, 12B are located outside all the internal electrode layers 13, 15 in the third direction D3. The pair of outer layer portions 12A, 12B are positioned so as to sandwich all the internal electrode layers 13, 15 in the third direction D3. The thickness of one of the pair of outer layer portions 12A and 12B is 5% to 10% of the thickness of the entire element body 3 in the third direction D3.

[0051] Figure 7 is an enlarged view of the element body in the lead-out portion 15b. Figure 7 As shown, the plurality of internal electrode layers 15 protrude from the plurality of dielectric layers 12. Similarly, the plurality of internal electrode layers 13 also protrude from the plurality of dielectric layers 12. The lead portions 13b, 15b of the internal electrode layers 13, 15 protrude from the plurality of dielectric layers 12 on each end surface 3e. The lead portions 13b, 15b of the internal electrode layers 13, 15 protrude from the pair of outer layer portions 12A, 12B on each end surface 3e in the first direction D1.

[0052] There is a correlation between the protrusion length P1 of the plurality of internal electrode layers 13 and 15 protruding from the pair of outer layer portions 12A and 12B and the sulfur content in the element body 3. The protrusion length P1 is the maximum length of the internal electrode layers 13 and 15 protruding from the pair of outer layer portions 12A and 12B along the first direction D1. The protrusion length P1 depends on the residual amount of sulfur in the element body 3. In the element body 3, the more the residual amount of sulfur is, the larger the protrusion length P1 is.

[0053] Figure 8 This is a graph showing the relationship between sulfur content and protrusion length. Figure 8 In the figure, data DA1 represents the curve of the measured value of the protrusion length P1 relative to the sulfur content. Data DA2 is an approximate line of all data DA1. In the measurement of the protrusion length P1, Fig. 9 As shown, by scanning in the direction of arrow α, a distribution map in the first direction D1 is obtained for the end surface 3e of the fired element body 3. A laser microscope, for example, is used to obtain the distribution map. For example, by scanning in the direction of arrow α, the maximum length of the internal electrode layer 15 protruding from the pair of outer layer parts 12A and 12B is measured, and the maximum length is recorded as the protruding length P1. The direction of arrow α is, for example, the third direction D3.

[0054] The multilayer capacitor C1 includes a pair of external electrode terminals 5. The pair of external electrode terminals 5 are arranged on the outer surface of the element body 3. The pair of external electrode terminals 5 are separated from each other. The external electrode terminals 5 may be arranged indirectly on the dielectric layer 12 via an electrical insulating film. The external electrode terminals 5 are arranged on the corresponding end surface 3e side of the element body 3. In the present embodiment, each external electrode terminal 5 is arranged on a pair of side surfaces 3a, a pair of side surfaces 3c, and one end surface 3e.

[0055] The external electrode terminal 5 is formed to cover five surfaces, namely, a pair of side surfaces 3a, an end surface 3e, and a pair of side surfaces 3c, and ridges 3g, 3i, and 3j. The external electrode terminal 5 is electrically connected to the corresponding internal electrode layers 13 and 15. The external electrode terminal 5 includes, for example, a plurality of electrode layers. For example, the external electrode terminal 5 includes a first electrode layer and a second electrode layer covering the first electrode layer.

[0056] exist Figure 2 In the example shown, in the first direction D1, the length B of the external electrode terminal 5 is 0.10 to 0.90 mm. The gap G between a pair of external electrode terminals 5 in the first direction D1 is 0.20 to 3.20 mm. For example, in the first direction D1, the length B of the external electrode terminal 5 is 0.70 mm. The gap G between a pair of external electrode terminals 5 in the first direction D1 is 1.95 mm.

[0057] In the present embodiment, the first electrode layer includes a sintered metal layer. The sintered metal layer is formed by sintering a conductive paste applied to the surface of the element body 3. The sintered metal layer is formed by sintering a metal component (metal powder) contained in the conductive paste. In the present embodiment, the sintered metal layer is composed of Cu. The sintered metal layer can also be composed of Ni. The sintered metal layer contains a base metal. The conductive paste, for example, contains a powder composed of Cu or Ni, a glass component, an organic binder, and an organic solvent.

[0058] The second electrode layer is formed on the first electrode layer by plating. In the present embodiment, the second electrode layer includes a first plating layer and a second plating layer. In the present embodiment, the first plating layer is formed on the conductive resin layer of the first electrode layer by Ni plating. The first plating layer is a Ni plating layer. The first plating layer may also be a Sn plating layer, a Cu plating layer or an Au plating layer. The first plating layer includes Ni, Sn, Cu or Au. The first plating layer covers the sintered metal layer.

[0059] The second plating layer is formed on the first plating layer by plating. The second plating layer is a solder plating layer. In the example shown in this embodiment, the second plating layer is formed on the first plating layer by plating Sn. The second plating layer is a Sn plating layer. The second plating layer may also be a Sn-Ag alloy plating layer, a Sn-Bi alloy plating layer or a Sn-Cu alloy plating layer. The second plating layer contains Sn, Sn-Ag alloy, Sn-Bi alloy or Sn-Cu alloy.

[0060] Next, the effects of the above-mentioned multilayer capacitor C1 are described. In the element body 3 of the multilayer capacitor C1, the weight ratio of the metal containing Ni is 20% to 25%, and the weight ratio of sulfur is 3ppm to 20ppm. In this case, the generation of cracks in the element body 3 is suppressed, and the desired electrical characteristics are also ensured, and the connection reliability between the external electrode terminal 5 and the internal electrode layers 13 and 15 is improved. Therefore, the manufacturing capacity can be improved.

[0061] Fig.10 This is a graph showing the relationship between sulfur content, capacitance, and thermal cracking of components. Fig.10 In the graph, data DA3 represents a curve of capacitance CV value with respect to sulfur content. Data DA4 represents a curve of element body thermal crack generation rate with respect to sulfur content. Data DA5 is an approximate line of data DA3. Data DA6 is an approximate line of data DA3.

[0062] Data DA3 is the CV value calculated from the capacitance measured 30 times for each batch of multiple batches with different sulfur contents. Data DA4 is the result of the thermal test. In the thermal test, the fired element 3 was immersed in a 400°C solder bath for 3 seconds, taken out and judged whether cracks occurred. Data D4 is the crack generation rate in 60 determinations of repeated immersion in the solder bath and determination of crack generation 60 times.

[0063] When the end face 3e is viewed from a direction perpendicular to the end face 3e, the ratio of the area occupied by the plurality of internal electrode layers 13 and 15 to the area of ​​the end face 3e may be 5% to 12%. That is, the ratio of the exposed area of ​​the lead portions 13b and 15b to the area of ​​the end face 3e may be 5% to 12%. In this case, it is easy to achieve a balance in the content of sulfur contained in the internal electrode layers 13 and 15. Therefore, the manufacturing capacity can be improved. For example, it is considered that the larger the area of ​​the internal electrode layers 13 and 15 exposed from the end face 3e, the easier it is for sulfur to be released from the element body 3 in the debinding process.

[0064] In each of the plurality of internal electrode layers 13 and 15, when the end face 3e is viewed from a direction perpendicular to the end face 3e, the value obtained by dividing the area of ​​the internal electrode layer 13 and 15 exposed from the plurality of dielectric layers 12 by the volume of the internal electrode layer 13 and 15 may be 0.15 to 0.40. That is, the ratio of the exposed area of ​​the lead portion 13b and 15b to the volume of the internal electrode layer 13 and 15 may be 0.15 to 0.40. In this case, it is easy to achieve a balance in the content rate of sulfur in the element body 3. Therefore, the manufacturing capacity can be improved. For example, it is considered that the larger the area of ​​the internal electrode layer 13 and 15 exposed from the end face 3e relative to the volume of the internal electrode layer 13 and 15 containing sulfur, the less likely sulfur is to be released from the element body 3 in the binder removal process and remain in the element body 3.

[0065] When the width of the lead portion 15b in the second direction D2 is "W1" and the width of the overlapping portion 15c in the second direction D2 is "W2", 1-(W1 / W2) may be 0.35 to 0.55. That is, the elongation may be 35% to 55%. In this case, it is easy to reduce the sulfur content in the element body 3 and to ensure the thickness of the external electrode terminal 5. Therefore, the manufacturing capacity can be improved, and the infiltration of the liquid into the internal electrode layers 13 and 15 can be suppressed. For example, in the case where the external electrode terminal 5 is formed by dipping into a solder bath, if the width W1 of the lead portion 15b in the second direction D2 is too large, it is difficult to ensure the thickness of the external electrode terminal 5.

[0066] When viewed from the first direction D1, if the distance WG1 from the overlapping portions 13c, 15c to the edge of the external electrode terminal 5 in the second direction D2 is too small, the risk of the internal electrode layers 13, 15 being exposed from the side surface 3c can be reduced. If the width W1 of the lead portions 13b, 15b in the second direction D2 is too large, when viewed from the first direction D1, the distance WG2 from the lead portions 13b, 15b to the edge of the external electrode terminal 5 in the second direction D2 becomes small, making it difficult to ensure the thickness of the external electrode terminal 5.

[0067] The thickness of one of the pair of outer layer portions 12A and 12B may be 5% to 10% of the thickness of the entire element body in the third direction D3. In this case, it is easy to reduce the sulfur content in the element body 3 and to ensure the thickness of the external electrode terminal 5. Therefore, the manufacturing capacity can be improved, and the intrusion of liquid into the internal electrode layers 13 and 15 can be suppressed. For example, in the case where the external electrode terminal 5 is formed by dipping into a solder bath, the smaller the thickness of one of the pair of outer layer portions 12A and 12B, the lower the sulfur content, but it is difficult to ensure the thickness of the external electrode terminal 5.

[0068] Next, use Fig.11 Examples 1 to 12 and Comparative Examples 1 to 5 are described. In the multilayer capacitors of Examples 1 to 12, the weight ratio of the metal containing Ni is 20% to 25%, and the weight ratio of sulfur is 3 ppm to 20 ppm. In this case, it was confirmed that the thermal crack generation rate in the element body 3 was 0%, the capacitance CV value was 1.22% to 1.49%, and the protrusion length P1 was 3.6 μm or more.

[0069] In the multilayer capacitors of Examples 1 to 7 and Examples 9 to 12, the ratio of the exposed area of ​​the lead portions 13b and 15b to the area of ​​the end surface 3e was 5% to 12%. In this case, the metal content was confirmed to be 20.4% to 24.8% and the sulfur content was 3.7 ppm to 17.2 ppm.

[0070] In the multilayer capacitors of Examples 1 to 8 and Examples 10 to 12, the ratio of the exposed area of ​​the lead portions 13b and 15b to the volume of the internal electrode layers 13 and 15 was 0.15 to 0.40. In this case, the metal content was confirmed to be 20.4% to 24.8% and the sulfur content was 3.7 ppm to 17.2 ppm.

[0071] The elongation of the multilayer capacitors of Examples 1 to 9 and Example 12 was 35% to 55%. In this case, it was confirmed that the metal content was 20.4% to 24.8% and the sulfur content was 3.7 ppm to 17.2 ppm.

[0072] In the multilayer capacitors of Examples 1 to 10, the thickness of each outer layer portion 12A, 12B is 5% to 10% of the thickness of the entire element body in the third direction D3. In this case, the metal content was confirmed to be 20.4% to 24.8%, and the sulfur content was 3.7 ppm to 17.2 ppm. Furthermore, according to the multilayer capacitors of Examples 1 to 7, it was confirmed that the infiltration of the plating solution was also prevented.

[0073] As mentioned above, although the embodiment and the modification of this invention were described, this invention is not necessarily limited to the above-mentioned embodiment, and various changes can be made without departing from the scope of the gist.

[0074] For example, the structure of the element body 3 of the multilayer capacitor C1 may be other than the structures shown in Examples 1 to 12. The structure in which the weight ratio of the metal containing Ni is 20% to 25% and the weight ratio of sulfur is 3 ppm to 20 ppm may be controlled by a process other than the binder removal process.

[0075] As can be understood from the description of the above-mentioned embodiments, this specification includes disclosures of the following aspects.

[0076] (Note 1)

[0077] A multilayer capacitor comprising:

[0078] An element body, wherein a plurality of dielectric layers extending in first and second directions orthogonal to each other and a plurality of internal electrode layers are alternately stacked in a third direction intersecting the first and second directions, the element body comprising at least one end face of at least one of the plurality of internal electrode layers exposed from the plurality of dielectric layers; and

[0079] an external electrode terminal, which is arranged on the at least one end surface and connected to the at least one internal electrode layer,

[0080] In the element body, the weight ratio of the metal containing Ni is 20% to 25%, and the weight ratio of sulfur is 3ppm to 20ppm.

[0081] (Note 2)

[0082] The multilayer capacitor according to Supplementary Note 1, wherein:

[0083] When the end surface is viewed in plan from a direction perpendicular to the end surface, a ratio of an area occupied by the plurality of internal electrode layers to an area of ​​the end surface is 5% to 12%.

[0084] (Note 3)

[0085] The multilayer capacitor according to Supplementary Note 1 or 2, wherein:

[0086] In each of the plurality of internal electrode layers, when the end face is viewed in plan from a direction perpendicular to the end face, a value obtained by dividing an area of ​​the internal electrode layer exposed from the plurality of dielectric layers by a volume of the internal electrode layer is 0.15 to 0.40.

[0087] (Note 4)

[0088] The multilayer capacitor according to any one of Appendixes 1 to 3, wherein:

[0089] The at least one end surface includes a pair of end surfaces where different internal electrode layers among the plurality of internal electrodes are exposed,

[0090] The plurality of internal electrode layers include a pair of internal electrode layers adjacent to each other and exposed at different end faces of the pair of end faces,

[0091] The pair of internal electrode layers each include an overlapping portion that overlaps each other, and a lead portion that is connected to the overlapping portion, extends from the overlapping portion in the first direction, and is exposed at the end surface.

[0092] In a case where the width of the lead-out portion in the second direction is “ W1 ” and the width of the overlapped portion in the second direction is “ W2 ”, 1-( W1 / W2 ) is 0.35 to 0.55.

[0093] (Note 5)

[0094] The multilayer capacitor according to any one of Appendixes 1 to 4, wherein:

[0095] The plurality of dielectric layers form a pair of outer layer portions, the pair of outer layer portions being located outside the plurality of internal electrode layers in the third direction and being positioned so as to sandwich the plurality of internal electrode layers.

[0096] The thickness of one of the pair of outer layer parts is 5% to 10% of the overall thickness of the element body in the third direction.

Claims

1. A stacked capacitor, wherein: have: An element body, wherein a plurality of dielectric layers extending in first and second directions orthogonal to each other and a plurality of internal electrode layers are alternately stacked in a third direction intersecting the first and second directions, the element body comprising at least one end face of at least one of the plurality of internal electrode layers exposed from the plurality of dielectric layers; and an external electrode terminal, which is arranged on the at least one end surface and connected to the at least one internal electrode layer, In the element body, the weight ratio of the metal containing Ni is 20% to 25%, and the weight ratio of sulfur is 3ppm to 20ppm.

2. The multilayer capacitor according to claim 1, wherein: When the end surface is viewed in plan from a direction perpendicular to the end surface, a ratio of an area occupied by the plurality of internal electrode layers to an area of ​​the end surface is 5% to 12%.

3. The multilayer capacitor according to claim 1 or 2, wherein: In each of the plurality of internal electrode layers, when the end face is viewed in plan from a direction perpendicular to the end face, a value obtained by dividing an area of ​​the internal electrode layer exposed from the plurality of dielectric layers by a volume of the internal electrode layer is 0.15 to 0.

40.

4. The multilayer capacitor according to claim 1 or 2, wherein: The at least one end surface includes a pair of end surfaces where different internal electrode layers among the plurality of internal electrodes are exposed, The plurality of internal electrode layers include a pair of internal electrode layers adjacent to each other and exposed at different end faces of the pair of end faces, The pair of internal electrode layers each include an overlapping portion that overlaps each other, and a lead portion that is connected to the overlapping portion, extends from the overlapping portion in the first direction, and is exposed at the end surface. In a case where the width of the lead-out portion in the second direction is “ W1 ” and the width of the overlapped portion in the second direction is “ W2 ”, 1-( W1 / W2 ) is 0.35 to 0.

55.

5. The multilayer capacitor according to claim 1 or 2, wherein: The plurality of dielectric layers form a pair of outer layer portions, the pair of outer layer portions being located outside the plurality of internal electrode layers in the third direction and being positioned so as to sandwich the plurality of internal electrode layers. The thickness of one of the pair of outer layer portions is 5% to 10% of the overall thickness of the element body in the third direction.

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