Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/224—Housing; Encapsulation
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/005—Electrodes
  • H01G4/012—Form of non-self-supporting electrodes
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/018—Dielectrics
  • H01G4/06—Solid dielectrics
  • H01G4/08—Inorganic dielectrics
  • H01G4/12—Ceramic dielectrics
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/002—Details
  • H01G4/228—Terminals
  • H01G4/232—Terminals electrically connecting two or more layers of a stacked or rolled capacitor
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
  • H01G4/00—Fixed capacitors; Processes of their manufacture
  • H01G4/30—Stacked capacitors

Definitions

• the present disclosure relates to a multilayer ceramic electronic component.
• Patent Document 1 A conventional multilayer ceramic electronic component is described in, for example, Patent Document 1.
• a multilayer ceramic electronic component includes an active portion in which a plurality of first dielectric layers and internal electrode layers are alternately laminated in a predetermined direction, and covering portions located at both ends of the active portion in the predetermined direction.
• a substantially rectangular parallelepiped-shaped laminate having a first surface and a second surface facing each other in the predetermined direction, a first side surface and a second side surface facing each other, and a first end surface and a second end surface facing each other.
• a laminate having; a first external electrode located from the first end surface to at least one of the first surface and the second surface; a second external electrode located from the second end surface to the at least one of the first surface and the second surface; a protective layer having the same main component as the first dielectric layer, located on the first side surface and the second side surface, The first external electrode and the second external electrode are respectively connected to different internal electrode layers, The thickness of the protective layer is 30 ⁇ m or less,
• the covering portion includes a plurality of second dielectric layers having the same main component as the first dielectric layer and dummy electrode layers having the same main component as the internal electrode layer, which are alternately stacked in the predetermined direction. The distance between the dummy electrode layers is 1 to 8 times the distance between the internal electrode layers.
• FIG. 1 is a perspective view showing a multilayer ceramic capacitor of this embodiment.
• FIG. 2 is a perspective view showing the element body components of the multilayer ceramic capacitor shown in FIG. 1.
• FIG. 3 is an exploded perspective view showing the element body parts of FIG. 2; 4 is a side view showing the element body component of FIG. 3.
• FIG. 2 is a plan view showing an example of a pattern of a dummy electrode layer in the multilayer ceramic capacitor shown in FIG. 1.
• FIG. 2 is a plan view showing an example of a pattern of a dummy electrode layer in the multilayer ceramic capacitor shown in FIG. 1.
• FIG. 1 is a perspective view showing a multilayer ceramic capacitor of this embodiment.
• FIG. 2 is a perspective view showing the element body components of the multilayer ceramic capacitor shown in FIG. 1.
• FIG. 2 is a plan view showing an example of a pattern
• FIG. 2 is a plan view showing an example of a pattern of a dummy electrode layer in the multilayer ceramic capacitor shown in FIG. 1.
• FIG. 7 is a graph showing the relationship between the distance between dummy electrode layers and the amount of side surface deformation of the element body component.
• FIG. 3 is a diagram illustrating an example of deformation of a base component and an amount of side deformation.
• FIG. 7 is a diagram illustrating another example of the deformation of the element body component and the amount of side deformation.
• 2 is an exploded perspective view showing an example of a laminate in the multilayer ceramic capacitor of FIG. 1.
• FIG. 2 is an exploded perspective view showing an example of a laminate in the multilayer ceramic capacitor of FIG. 1.
• FIG. 1 is an exploded perspective view showing an example of a laminate in the multilayer ceramic capacitor of FIG. 1.
• FIG. 2 is an exploded perspective view showing an example of a laminate in the multilayer ceramic capacitor of FIG. 1.
• FIG. FIG. 2 is a perspective view showing a ceramic green sheet printed with a conductive paste that becomes an internal electrode layer.
• FIG. 2 is a perspective view showing a ceramic green sheet printed with a conductive paste that becomes an internal electrode layer.
• FIG. 2 is a perspective view showing a ceramic green sheet printed with a conductive paste that becomes a dummy electrode layer.
• FIG. 8 is a perspective view showing a stacked state of the ceramic green sheets of FIGS. 8A, 8B, and 8C.
• FIG. 3 is a perspective view showing a mother laminate.
• FIG. 2 is a perspective view showing an element body precursor.
• FIG. 3 is a perspective view showing a plurality of element body precursors arranged on a support sheet. It is a figure explaining the process of forming a protective layer on the side surface of an element body precursor. It is a figure explaining the process of forming a protective layer on the side surface of an element body precursor. It is a figure explaining the process of forming a protective layer on the side surface of an element body precursor. FIG. 3 is a perspective view showing a plurality of element body parts on which protective layers are formed.
• FIG. 2 is a perspective view showing a stacked state of ceramic green sheets.
• FIG. 3 is a perspective view showing a mother laminate.
• FIG. 2 is a perspective view showing an element body precursor.
• FIG. 3 is a perspective view showing a plurality of element body precursors arranged on a support sheet.
• FIG. 2 is a perspective view showing a multilayer ceramic capacitor.
• FIG. 3 is a perspective view showing a mother laminate.
• FIG. 2 is a perspective view showing a multilayer ceramic capacitor.
• Multilayer ceramic capacitors which are an example of such electronic components, are mainly products with a side length of 1 mm or less, but there is a demand for further miniaturization and larger capacity.
• Patent Document 1 discloses a multilayer ceramic capacitor that reduces the mismatch in shrinkage behavior between the active part and the covering part by adjusting the particle size of the ceramic material forming the active part and the particle size of the ceramic material forming the covering part. is disclosed.
• the multilayer ceramic electronic component of the present disclosure is not limited to a multilayer ceramic capacitor, and includes, for example, a multilayer piezoelectric element, a multilayer thermistor element, a multilayer chip coil, and a multilayer ceramic capacitor. It can be applied to laminated ceramic electronic components such as ceramic multilayer substrates.
• the drawings used in the following explanation are schematic, and the number of laminated layers, dimensional ratios, etc. in the drawings do not necessarily correspond to the actual ones.
• an orthogonal coordinate system XYZ is defined for convenience in some drawings.
• terms such as upper end or lower end may be used with the positive side in the Z-axis direction as the upper side.
• the X-axis direction is also referred to as the first direction or the length direction.
• the Y-axis direction is also referred to as the second direction or the width direction.
• the Z-axis direction is also referred to as the third direction or the height direction.
• internal electrode layers and dummy electrode layers are hatched for ease of illustration.
• FIG. 1 is a perspective view showing the multilayer ceramic capacitor of this embodiment
• FIG. 2 is a perspective view showing the element body parts of the multilayer ceramic capacitor of FIG. 1
• FIG. 3 is a perspective view showing the element body parts of the multilayer ceramic capacitor of FIG.
• FIG. 4 is an exploded perspective view showing the element body components of FIG. 3
• FIG. 5A, 5B, and 5C are plan views showing examples of patterns of dummy electrode layers in the multilayer ceramic capacitor of FIG. 1
• FIG. 6A is a graph showing the relationship between the distance between the dummy electrode layers and the amount of side deformation
• 6B is a diagram illustrating an example of the deformation of the element body precursor and the amount of side deformation
• 6C is a diagram illustrating another example of the deformation and side deformation amount of the element body precursor.
• 6B and 6C are side views of the element body component, and correspond to the side view shown in FIG. 4.
• 7A, 7B, and 7C are exploded perspective views showing an example of a laminate in the multilayer ceramic capacitor of FIG. 1.
• FIG. 1
• the multilayer ceramic capacitor 1 of this embodiment includes an element body component 2 and an external electrode 3, as shown in FIG.
• the element body component 2 has a laminate (also referred to as an element body precursor) 13 and a protective layer 6, as shown in FIGS. 2 and 3.
• a laminate also referred to as an element body precursor
• a protective layer 6 as shown in FIGS. 2 and 3.
• FIG. 2 is a diagram showing the element body part 2 before firing, and also a diagram showing the element body part 2 after firing.
• the laminate 13 has an active part 19 and a covering part 20.
• the active part 19 is configured by alternately stacking a plurality of first dielectric layers 4 and internal electrode layers 5.
• the first dielectric layer 4 and the internal electrode layer 5 are laminated in a predetermined direction (third direction).
• the interval between the internal electrode layers 5 in the third direction may be a predetermined interval a.
• the covering portion 20 is located at both ends of the active portion 19 in the third direction.
• the covering portion 20 is constructed by alternately laminating a plurality of second dielectric layers 16 and dummy electrode layers 17.
• the second dielectric layer 16 and the dummy electrode layer 17 are stacked in the third direction.
• the distance between the dummy electrode layers 17 in the third direction may be a predetermined distance b.
• the first dielectric layer 4 and the second dielectric layer 16 may be collectively referred to as dielectric layers 4 and 16
• the internal electrode layer 5 and dummy electrode layer 17 may be collectively referred to as electrode layers 5 and 17. be.
• the laminate 13 has a substantially rectangular parallelepiped shape (see FIGS. 2 and 3).
• the laminate 13 has a first surface 7a and a second surface 7b facing each other in the third direction, a first end surface 8a and a second end surface 8b facing each other in the first direction, and a first surface 7a and a second surface 7b facing each other in the second direction. It has a side surface 9a and a second side surface 9b.
• the internal electrode layer 5 is exposed at the first end surface 8a or the second end surface 8b depending on the polarity. Internal electrode layer 5 is exposed on first side surface 9a and second side surface 9b.
• the first surface 7a and the second surface 7b may be perpendicular to the third direction.
• the first end surface 8a and the second end surface 8b may be perpendicular to the first direction.
• the first side surface 9a and the second side surface 9b may be perpendicular to the second direction.
• the first surface 7a and the second surface 7b may be collectively referred to as main surfaces 7a and 7b
• the first end surface 8a and the second end surface 8b may be collectively referred to as end surfaces 8a and 8b
• the The side surface 9a and the second side surface 9b may be collectively referred to as side surfaces 9a and 9b.
• the first dielectric layer 4 is made of an insulating material.
• the first dielectric layer 4 is made of a ceramic material whose main components are, for example, BaTiO 3 (barium titanate), CaTiO 3 (calcium titanate), SrTiO 3 (strontium titanate), BaZrO 3 (barium zirconate), etc. may have been done.
• main component refers to a component having the highest composition ratio in the material or member of interest. The composition ratio may be the content concentration (mol%).
• the internal electrode layer 5 is made of a conductive material.
• the internal electrode layer 5 may be made of a metal material containing, for example, Ni (nickel), Pd (palladium), Ag (silver), Cu (copper), or the like as a main component.
• the second dielectric layer 16 is made of an insulating material.
• the second dielectric layer 16 may be made of a ceramic material containing, for example, BaTiO 3 , CaTiO 3 , SrTiO 3 , BaZrO 3 or the like as a main component.
• the second dielectric layer 16 has the same main components as the first dielectric layer 4.
• the dummy electrode layer 17 is made of a conductive material.
• the dummy electrode layer 17 may be made of a metal material containing Ni, Pd, Ag, Cu, or the like as a main component, for example.
• the dummy electrode layer 17 has the same main components as the internal electrode layer 5.
• the pattern of the dummy electrode layer 17 (the planar shape when viewed from the direction perpendicular to the main surfaces 7a and 7b) may be any pattern as long as it does not short-circuit the first external electrode 3a and the second external electrode 3b.
• the pattern of the dummy electrode layer 17 may be different from the pattern of the internal electrode layer 5.
• the pattern of the dummy electrode layer 17 is the pattern shown in FIG. 5B.
• the external electrode 3 has a first external electrode 3a and a second external electrode 3b.
• the first external electrode 3a is located from the first end surface 8a to at least one of the first surface 7a and the second surface 7b (also referred to as an electrode forming surface).
• the first external electrode 3a is connected to the internal electrode layer 5 exposed on the first end surface 8a.
• the second external electrode 3b is located from the second end surface 8b to the electrode forming surface.
• the second external electrode 3b is connected to the internal electrode layer 5 exposed on the second end surface 8b.
• the external electrode 3 may have a base layer connected to the laminate 13 and a plating outer layer covering the base layer. Since the external electrode 3 has a plating outer layer, solder bonding between the external electrode 3 and an external substrate or external wiring becomes easy.
• the base layer may be formed by applying a conductive paste for the external electrodes 3 to the fired element part 2 and baking it.
• the base layer may be formed by applying a conductive paste for the external electrodes 3 to the element body part 2 before firing, and firing the element body part 2 and the conductive paste simultaneously.
• the outer plating layer may be formed using a thin film forming technique such as electroless plating or electrolytic plating.
• the base layer and the outer plating layer may be a single layer or a plurality of layers.
• the external electrode 3 may have a base layer and a conductive resin layer without having an outer plating layer.
• the base layer may contain metals such as Ni, Pd, Ag, and Cu, or alloys thereof.
• the outer plating layer may contain metals such as Ni, Sn (tin), and Cu, or alloys thereof.
• the protective layer 6 is located on the first side surface 9a and the second side surface 9b.
• the protective layer 6 electrically insulates the internal electrode layers 5 of different polarities exposed on the side surfaces 9a and 9b. Further, the protective layer 6 physically protects the end portions of the internal electrode layer 5 exposed on the side surfaces 9a and 9b.
• the thickness of the protective layer 6 is 30 ⁇ m or less. The thickness of the protective layer 6 may be 5 ⁇ m or more and 30 ⁇ m or less.
• the protective layer 6 is made of an insulating material.
• the protective layer 6 may be composed of a ceramic material, in which case the protective layer 6 may have insulating properties and relatively high mechanical strength. Further, when the protective layer 6 is made of a ceramic material, it is possible to simultaneously fire the laminate 13 and the protective layer 6.
• the protective layer 6 may be made of a ceramic material containing, for example, BaTiO 3 , CaTiO 3 , SrTiO 3 , BaZrO 3 or the like as a main component.
• the boundary between the laminate 13 and the protective layer 6 is shown by a two-dot chain line, but the actual boundary does not appear clearly.
• the firing shrinkage behavior of the protective layer 6 will have a large influence on the firing shrinkage behavior of the active region 19. Therefore, the components of the internal electrode layer 5 (for example, the firing shrinkage behavior of the protective layer 6 may be brought close to that of the active part 19 by including a component (main component of the internal electrode layer 5). As a result, uniform firing shrinkage behavior can be obtained over the entire element body part 2.
• the thickness of the protective layer 6 is small, characteristics such as electrical strength and physical strength of the protective layer 6 tend to deteriorate. In particular, if voids or conductive substances exist in the protective layer 6, the characteristics of the protective layer 6 will deteriorate significantly, leading to a decrease in insulation resistance and reliability.
• the ceramic material constituting the protective layer 6 does not need to contain the components of the internal electrode layer 5. Therefore, even when the thickness of the protective layer 6 is 15 ⁇ m or less, a decrease in insulation resistance and a decrease in reliability can be reduced.
• the covering portion 20 is made up of alternating layers of a second dielectric layer 16 whose main component is the same as that of the first dielectric layer 4 and a dummy electrode layer 17 whose main component is the same as that of the internal electrode layer 5.
• the stacking direction of the second dielectric layer 16 and the dummy electrode layer 17 is the same as the stacking direction of the first dielectric layer 4 and the internal electrode layer 5.
• the dummy electrode layer 17 may be located at the center of the covering portion 20 in the first direction, and may be out of contact with the first external electrode 3a and the second external electrode 3b. In this case, short circuit between the first external electrode 3a and the second external electrode 3b can be suppressed.
• the dummy electrode layer 17 may be located from the first side surface 9a to the second side surface 9b.
• the dummy electrode layer 17 and the internal electrode layer 5 may have the same length in the second direction orthogonal to the first side surface 9a.
• the dimension of the dummy electrode layer 17 in the first direction may be approximately 1/4 to 2/3 times the dimension of the covering portion 20 in the first direction.
• FIG. 5A shows an example in which the dummy electrode layer 17 is located at the center of the covering portion 20 in the first direction
• the dummy electrode layer 17 may be located closer to the first end surface 8a, It may be located closer to the end surface 8b.
• the covering portion 20 may include a plurality of dummy electrode layers 17 having mutually different positions in the first direction.
• the laminate 13 is obtained by cutting the base laminate 11 (see FIGS. 10 and 11).
• the mother laminate 11 is a mother laminate precursor formed by laminating ceramic green sheets (hereinafter also simply referred to as green sheets) for the dielectric layers 4 and 16 on which patterns to become the electrode layers 5 and 17 are printed. , it can be formed by pressing in the stacking direction.
• the covering portion 20 includes a plurality of dummy electrode layers 17 having different positions in the first direction, when pressing the mother laminate precursor to produce the mother laminate 11, the dielectric layers 4 and 16 and the electrode layer In addition, the internal strain of the dielectric layers 4 and 16 and the electrode layers 5 and 17 can be dispersed. As a result, a decrease in reliability of the multilayer ceramic capacitor 1 can be suppressed.
• the dummy electrode layer 17 may include a first dummy electrode layer 17a and a second dummy electrode layer 17b, as shown in FIG. 5B.
• the first dummy electrode layer 17a extends from the first end surface 8a toward the second end surface 8b.
• the first dummy electrode layer 17a may be connected to the first external electrode 3a.
• the second dummy electrode layer 17b extends from the second end surface 8b toward the first end surface 8a.
• the second dummy electrode layer 17b may be connected to the second external electrode 3b.
• the first dummy electrode layer 17a and the second dummy electrode layer 17b are not in contact with each other, and a gap S exists between the first dummy electrode layer 17a and the second dummy electrode layer 17b.
• the first dummy electrode layer 17a and the second dummy electrode layer 17b may be located from the first side surface 9a to the second side surface 9b.
• the first dummy electrode layer 17a, the second dummy electrode layer 17b, and the internal electrode layer 5 may have the same length in the second direction perpendicular to the first side surface 9a.
• the dummy electrode layer 17 overlaps the corners of the main surfaces 7a, 7b when viewed from the direction perpendicular to the main surfaces 7a, 7b.
• the dimensions of the first dummy electrode layer 17a and the second dummy electrode layer 17b in the first direction may be approximately 1/4 to 1/3 times the dimension of the covering portion 20 in the first direction.
• the dummy electrode layer 17 may include a first dummy electrode layer 17a, a second dummy electrode layer 17b, and at least one third dummy electrode layer 17c, as shown in FIG. 5C.
• the first dummy electrode layer 17a extends from the first end surface 8a toward the second end surface 8b.
• the first dummy electrode layer 17a may be connected to the first external electrode 3a.
• the second dummy electrode layer 17b extends from the second end surface 8b toward the first end surface 8a.
• the second dummy electrode layer 17b may be connected to the second external electrode 3b.
• the first dummy electrode layer 17a and the second dummy electrode layer 17b are not in contact with each other.
• the third dummy electrode layer 17c is located between the first dummy electrode layer 17a and the second dummy electrode layer 17b.
• the third dummy electrode layer 17c is not in contact with the first dummy electrode layer 17a and the second dummy electrode layer 17b.
• the first dummy electrode layer 17a and the second dummy electrode layer 17b may be located from the first side surface 9a to the second side surface 9b.
• the first dummy electrode layer 17a, the second dummy electrode layer 17b, and the internal electrode layer 5 may have the same length in the second direction orthogonal to the first side surface 9a.
• the dummy electrode layer 17 overlaps the corners of the main surfaces 7a, 7b when viewed from the direction perpendicular to the main surfaces 7a, 7b.
• the dielectric layers 4 and 16 and the electrode layers 5 and 17 are The adhesion of the dielectric layers 4 and 16 and the electrode layers 5 and 17 can be dispersed. As a result, a decrease in reliability of the multilayer ceramic capacitor 1 can be suppressed.
• the third dummy electrode layer 17c may be located from the first side surface 9a to the second side surface 9b.
• the third dummy electrode layer 17c and the internal electrode layer 5 may have the same length in the second direction orthogonal to the first side surface 9a. Since the first dummy electrode layer 17a, the second dummy electrode layer 17b, and the third dummy electrode layer 17c are located from the first side surface 9a to the second side surface 9b, the mother laminate precursor is pressed and the mother laminate is formed. 11, the adhesion between the dielectric layers 4, 16 and the electrode layers 5, 17 can be further improved, and the internal strain of the dielectric layers 4, 16 and the electrode layers 5, 17 can be further dispersed. can be done.
• the dimensions of the first dummy electrode layer 17a and the second dummy electrode layer 17b in the first direction may be approximately 1/4 to 1/3 times the dimension of the covering portion 20 in the first direction.
• the dimension of the third dummy electrode layer 17c in the first direction may be approximately 1/4 to 1/2 times the dimension of the covering portion 20 in the first direction.
• the number of gaps S existing between the first dummy electrode layer 17a and the second dummy electrode layer 17b is one.
• the number of gaps S is increased to two, so it is possible to reduce the possibility that the first dummy electrode layer 17a and the second dummy electrode layer 17b will be short-circuited.
• the at least one third dummy electrode layer 17c may be a plurality of third dummy electrode layers 17c that are not in contact with each other.
• the covering portion 20 may be configured by alternately stacking the dummy electrode layers 17 shown in FIG. 5B and the dummy electrode layers 17 shown in FIG. 5C with the second dielectric layer 16 in between. By alternately stacking the dummy electrode layers 17 of different patterns, internal stress can be dispersed in the pressing step of pressing the mother laminate precursor.
• FIG. 6A is a graph showing the relationship between the distance b between the dummy electrode layers 17 and the amount of side deformation d of the element body component 2
• FIGS. 6B and 6C illustrate the deformation of the element body component 2 and the amount of side deformation d.
• This is a diagram.
• the relationship shown in the graph of FIG. 6A was obtained by producing a sample of the element body part 2 and measuring the dimensions of the produced sample.
• dielectric layer green sheets green sheets
• the ratio b/a can be made a natural number, as in the case of the samples corresponding to the first to fourth data from the right end in the graph of FIG. 6A. It can be said that the horizontal axis of the graph in FIG. 6A is the number of green sheets for the first dielectric layer 4 that constitute one green sheet for the second dielectric layer 16.
• the ratio b /a can be less than 1.
• the vertical axis of the graph in FIG. 6A is the amount of lateral deformation d in the element body part 2 after firing.
• the side surface deformation amount d is half the difference between the maximum dimension S MAX and the minimum dimension S MIN between the side surfaces 9 a and 9 b in the element body part 2 after firing. It can be said that the smaller the side surface deformation amount d, the less the discrepancy in shrinkage behavior between the active part 19 and the covering part 20.
• a sample (element body part 2) prepared using a green sheet for a dielectric layer having a thickness of 1.0 ⁇ m was used.
• the length was 1.0 mm, and the width and height were 0.5 mm.
• the internal electrode layer 5 had a thickness of 0.8 ⁇ m after printing.
• the dummy electrode layer 17 may have the same thickness as the internal electrode layer 5 or may have a thicker thickness than the internal electrode layer 5. If the dummy electrode layer 17 is too thick, a step will be formed on the main surfaces 7a, 7b of the laminate 13 due to the dummy electrode layer 17, and internal strain during firing will induce cracks. To obtain the results shown in FIG. 6A, the thickness of the dummy electrode layer 17 was adjusted to a thickness that would not induce cracks.
• the thickness of the dummy electrode layer 17 may be, for example, about 1.5 times or more and 2.5 times or less the thickness of the internal electrode layer 5.
• the firing shrinkage behavior of the covering part 20 can be brought close to that of the active part 19.
• the covering portion 20 is a portion that does not contribute to the acquired capacity of the multilayer ceramic capacitor 1, and increasing the number of dummy electrode layers 17 of the covering portion 20 results in an increase in the cost of the multilayer ceramic capacitor 1. Therefore, the number of dummy electrode layers 17 may be set within a range in which the amount of side deformation d does not significantly affect the quality of the multilayer ceramic capacitor 1.
• the fired element body component 2 may have a shape in which both end portions in the height direction (Z-axis direction) protrude more in the width direction than the center portion, for example, as shown in FIG. 6B.
• the maximum dimension S MAX may be the dimension between the side surfaces 9a and 9b at the upper end or the lower end in the height direction
• the minimum dimension S MIN is the dimension between the side surfaces 9a and 9b at the center in the height direction. It may be a dimension.
• the fired element body component 2 may have a shape in which the central portion in the height direction protrudes more in the width direction than both end portions, for example, as shown in FIG. 6C.
• the maximum dimension S MAX may be the dimension between the side surfaces 9a and 9b at the center in the height direction
• the minimum dimension S MIN may be the dimension between the side surfaces 9a and 9b at the upper or lower end in the height direction. It may be a dimension.
• the active part 19 includes, for example, a first dielectric layer 4 having a thickness of approximately 0.4 ⁇ m to several ⁇ m after firing, and an internal electrode layer 5 having a thickness of approximately 0.4 ⁇ m to 2 ⁇ m after firing. Since it is composed of a total of several hundred to 1,000 laminated layers, the amount of shrinkage during firing is greater than that of the covering section 20, which is composed only of green sheets for dielectric layers and does not have an electrode layer. Cheap. As a result, cracks are likely to occur in the region R (see FIGS. 6B and 6C) spanning the active part 19 and the covering part 20 in the protective layer 6.
• the amount of lateral deformation d in the element body part 2 after firing is 5.1 ⁇ m. Met.
• the amount of side deformation d is It was 4.0 ⁇ m.
• the side surface deformation amount d was 2.4 ⁇ m.
• the side surface deformation amount d was 1.6 ⁇ m.
• the side surface deformation amount d was 1.2 ⁇ m.
• the element body component 2 after firing may have a shape as shown in FIG. 6B.
• the distance b between the dummy electrode layers 17 is equal to the distance a between the internal electrode layers 5. Limited to natural number times. As described above, by using a green sheet thinner than the dielectric layer green sheet as the green sheet for the second dielectric layer 16, the distance b between the dummy electrode layers 17 is reduced to the distance a between the internal electrode layers 5. It can be less than As shown in FIG. 6A, when each of the five dummy electrode layers 17 is arranged in the covering part 20 at an interval 0.5 times the interval between the internal electrode layers 5, the side deformation amount d is 3.5 ⁇ m. Met. Note that when the distance b between the dummy electrode layers 17 is less than the distance a between the internal electrode layers 5, the fired element body component 2 may have a shape as shown in FIG. 6C.
• the amount of side deformation d can be 3.0 ⁇ m or less, and as a result, , the occurrence of cracks in the protective layer 6 can be effectively suppressed.
• the value of the side surface deformation amount d also changes, but the tendency does not differ significantly from the trend of the results shown in FIG. 6A.
• the distance b between the dummy electrode layers 17 is between 1 and 8 times the distance a between the internal electrode layers 5.
• the distance b between the dummy electrode layers 17 is equal to the distance a between the internal electrode layers 5. Multiplied by a natural number.
• the distance b between the dummy electrode layers 17 can be adjusted to The distance a between the layers 5 can be r (r is a real number greater than 1) times the distance a.
• the ratio b/a is a non-integer multiple, if the distance b between the dummy electrode layers 17 is between 1 and 8 times the distance a between the internal electrode layers 5, the amount of side deformation d can be reduced to 3. It can be set to .0 ⁇ m or less. As a result, the occurrence of cracks in the protective layer 6 can be effectively suppressed.
• the green sheet for the dielectric layer a green sheet having a thickness of, for example, about 1.0 ⁇ m to about 5.0 ⁇ m can be used.
• the laminate 13 may include a covering portion 20 in which a plurality of dummy electrode layers 17 having the pattern shown in FIG. 5C are stacked with the second dielectric layer 16 in between.
• the covering portion 20 may have a structure in which a plurality of dummy electrode layers 17 are stacked while being shifted in the first direction, as shown in FIG. 7A. According to such a configuration, internal stress can be dispersed in the pressing step of pressing the mother laminate precursor, so that the multilayer ceramic capacitor 1 can have excellent reliability.
• the laminate 13 may include a covering portion 20 formed by laminating a predetermined number of second dielectric layers 16 having dummy electrode layers 17 having the pattern shown in FIG. 5B.
• the stacked body 13 may have a structure in which the upper surface of the covering section 20 located on the upper surface of the active section 19 is a dummy electrode layer 17. According to such a configuration, when forming the external electrodes 3 from the end faces 8a, 8b to the first surface 7a of the multilayer body 13, the external electrodes 3 can be firmly bonded to the multilayer body 13, so that the multilayer ceramic capacitor 1 can be It can be made highly reliable.
• the laminate 13 may include a covering portion 20 formed by laminating a predetermined number of second dielectric layers 16 having a dummy electrode layer 17 shown in FIG. 5B.
• the stacked body 13 has a dummy electrode layer 17 on the upper surface of the covering part 20 located on the upper surface of the active part 19, and a dummy electrode layer on the lower surface of the covering part 20 located on the lower surface of the active part 19. 17 may be used.
• the external electrode 3 when forming the external electrode 3 from the end surfaces 8a and 8b of the laminate 13 to the first surface 7a and the second surface 7b, the external electrode 3 can be firmly bonded to the laminate 13.
• the multilayer ceramic capacitor 1 can have excellent reliability. Further, since the element body part 2 can be handled without distinction in the vertical direction, the manufacturing process of the multilayer ceramic capacitor 1 can be made more efficient.
• the dummy electrode layer 17 has the same main component as the internal electrode layer 5, which makes it possible to bring the shrinkage behavior of the covering portion 20 close to that of the active portion 19. It is possible to adjust components other than the main component of the dummy electrode layer 17 to suit other purposes. For example, if the dummy electrode layer 17 is made of a metal material whose main component is Ni, Pd, Ag, Cu, etc., the dummy electrode layer 17 and the second dielectric layer 16 are bonded together when the element body component 2 is fired. It can be difficult to do. As shown in FIGS.
• the conductive paste that becomes the dummy electrode layer 17 may be a conductive paste containing ceramic powder.
• the ceramic powder of the conductive paste that will become the dummy electrode layer 17 and the ceramic powder of the dielectric layer sheet that will become the second dielectric layer 16 are sintered when the element body part 2 is fired, so that the dummy electrode layer 17 to the second dielectric layer 16 can be strengthened. As a result, peeling of the dummy electrode layer 17 from the second dielectric layer 16 can be suppressed.
• FIGS. 8A and 8B are perspective views showing a ceramic green sheet printed with a conductive paste that will become an internal electrode layer
• FIG. 8C is a perspective view showing a ceramic green sheet printed with a conductive paste that will become a dummy electrode layer.
• FIG. 9 is a perspective view showing a stacked state of the ceramic green sheets of FIGS. 8A, 8B, and 8C.
• FIG. 10 is a perspective view showing a mother laminate
• FIG. 11 is a perspective view showing an element body precursor
• FIG. 12 is a perspective view showing a plurality of element body precursors arranged on a support sheet.
• It is. 13A, 13B, and 13C are diagrams illustrating the process of forming a protective layer on the side surface of the element body precursor
• FIG. 14 is a perspective view showing a plurality of element body parts arranged on a support sheet. .
• a ceramic mixed powder made by adding additives to BaTiO 3 which is a ceramic dielectric material, is wet-pulverized and mixed in a bead mill, and then a polyvinyl butyral binder, a plasticizer, and an organic solvent are added and mixed to form a ceramic slurry. Create.
• a ceramic green sheet (hereinafter also simply referred to as a green sheet) 10 is formed on the carrier film using a die coater.
• the thickness of the green sheet 10 may be, for example, about 1 ⁇ m to 10 ⁇ m. By reducing the thickness of the green sheet 10, the capacitance of the multilayer ceramic capacitor 1 can be increased.
• Forming of the green sheet 10 is not limited to a die coater, and may be performed using, for example, a doctor blade coater or a gravure coater.
• the green sheet 10 for the second dielectric layer 16 may have the same main components as the green sheet 10 for the first dielectric layer 4.
• the green sheet 10 for the second dielectric layer 16 may be a stack of one or more green sheets 10 for the first dielectric layer 4.
• the thickness of the green sheet 10 for the second dielectric layer 16 may be eight times or less than the thickness of the green sheet 10 for the first dielectric layer 4.
• a conductive paste that will become the internal electrode layer 5 is printed on the green sheet 10 for the first dielectric layer 4 in a pattern as shown in FIGS. 8A and 8B.
• a conductive paste that will become the dummy electrode layer 17 is printed on the green sheet 10 for the body layer 16 in a pattern as shown in FIG. 8C.
• 8A and 8B show the internal electrode layer 5 printed on the green sheet 10 for the first dielectric layer 4 forming the active part 19.
• FIG. 8A and the pattern shown in FIG. 8B are used as the pattern of the internal electrode layer 5, the pattern shown in FIG. 8B may be formed by shifting the pattern shown in FIG. 8A.
• the conductive paste that becomes the internal electrode layer 5 and the dummy electrode layer 17 may be a conductive paste containing Ni as a main component.
• the conductive paste that becomes the internal electrode layer 5 and the dummy electrode layer 17 may contain metals such as Pd, Cu, and Ag, or alloys thereof, in addition to Ni, which is the main component.
• the conductive paste that becomes the internal electrode layer 5 will also be simply referred to as the internal electrode layer 5.
• the conductive paste that becomes the dummy electrode layer 17 is also simply referred to as the dummy electrode layer 17.
• the printing of the internal electrode layer 5 and the dummy electrode layer 17 is not limited to the screen printing method, and may be performed using, for example, a gravure printing method.
• the thickness of the internal electrode layer 5 may be, for example, about 1.0 ⁇ m or less.
• FIG. 9 is a perspective view showing a stacked state of green sheets 10 on which electrode layers 5 and 17 are printed.
• a predetermined number of green sheets 10 for the second dielectric layer 16 on which dummy electrode layers 17 are printed are stacked.
• a predetermined number of green sheets 10 for the first dielectric layer 4 on which internal electrode layers 5 are printed are stacked alternately, and then green sheets for the second dielectric layer 16 on which dummy electrode layers 17 are printed are stacked.
• a predetermined number of sheets of 10 are stacked.
• a predetermined number of green sheets 10 for the first dielectric layer 4 on which the internal electrode layers 5 are printed may be stacked while shifting the pattern of the internal electrode layers 5.
• the green sheets 10 on which the electrode layers 5 and 17 are printed are stacked on a support sheet (not shown).
• the support sheet may be an adhesive release sheet that can be adhesively and peeled off, such as a weak adhesive sheet or a foamed release sheet.
• a mother laminate precursor formed by laminating green sheets 10 on which electrode layers 5 and 17 are printed is pressed in the stacking direction to obtain a mother laminate 11 as shown in FIG. 10.
• the mother laminate precursor can be pressed using, for example, a hydrostatic press device. Inside the mother laminate 11, electrode layers 5 and 17 are embedded in layers with a green sheet 10 in between.
• a support sheet used when laminating the ceramic green sheets 10 is located below the base laminate 11.
• the broken line shown in FIG. 10 is a planned cutting line 12 indicating the position at which the mother laminate 11 is to be cut.
• the mother laminate 11 is cut along the planned cutting line 12 using a punch cutting device to obtain an element body precursor (laminate) 13 shown in FIG. 11.
• the method for cutting the mother laminate 11 is not limited to the method using a push-cut cutting device, and may be, for example, a method using a dicing saw device or the like.
• the main surface, end surface, and side surface of the mother laminate 11 correspond to the main surfaces 7a, 7b, end surfaces 8a, 8b, and side surfaces 9a, 9b of the element body precursor 13, respectively, and hence are given the same reference numerals below.
• a tray (not shown) in which pockets for individually storing a plurality of elemental body precursors 13 are arranged vertically and horizontally is prepared, and the cut surface (second side surface 9b) of the elemental body precursors 13 faces upward.
• a plurality of element body precursors 13 were arranged in a plurality of pockets, respectively.
• a support sheet 18 that can be adhesively and peeled off is placed over the cut surface of the element body precursor 13, and after fixing the plurality of element body precursors 13 on the support sheet 18, the tray is removed.
• FIG. 12 shows a plurality of element body precursors 13 fixed on a support sheet 18. The directions are aligned so that the cut surface (first side surface 9a) of the element body precursor 13 becomes an open surface.
• the cut surface may be cleaned to remove foreign matter adhering to the cut surface. Examples of the foreign matter adhering to the cut surface include debris from the green sheet 10, resin binder contained in the green sheet 10, and glue from the support sheet 18.
• the method for cleaning the cut surface may be, for example, a blast polishing method, a laser processing method, or the like.
• the resin sheet 27 may be a smooth sheet made of, for example, PET (polyethylene terephthalate), PP (polypropylene), etc., and having a thickness of about 10 ⁇ m to 40 ⁇ m.
• the resin sheet 27 may have flexibility.
• a release agent may be applied to the surface of the resin sheet 27 opposite to the surface facing the elastic sheet 24b to facilitate the removal of the green sheet 14 from the elastic sheet 24b.
• a plurality of element body precursors 13 fixed on the support sheet 18 are arranged so that the cut surfaces (first side surfaces 9a) face the green sheet 14.
• the support sheet 18 may be placed on the elastic sheet 24a.
• the green sheet 14 for the protective layer 6 a green sheet having a predetermined thickness that is easily bonded to the element body precursor 13 is prepared.
• the thickness of the green sheet 14 may be, for example, 5 ⁇ m to 30 ⁇ m.
• the green sheet 14 may have the same main components as the green sheet 10 for the first dielectric layer 4 . Thereby, the influence of the protective layer 6 on the characteristics of the multilayer ceramic capacitor 1 can be reduced.
• the green sheet 14 for the protective layer 6 may have the same composition as the green sheet 10 for the first dielectric layer 4. Note that the organic binder and solvent are removed in the degreasing step before firing, so they can be appropriately selected in consideration of ease of molding the green sheet 14, bondability with the element body precursor 13, and the like.
• Polyvinyl butyral binders have excellent plasticity and adhesive properties. Furthermore, the plasticity and adhesiveness of the polyvinyl butyral binder can be improved by heating it to a temperature 30° C. or more higher than the glass transition point Tg. Therefore, the green sheet 14 may be produced by dissolving a polyvinyl butyral binder and a plasticizer, which have a relatively low glass transition point Tg, in a mixed solvent of ethanol and toluene, and mixing and dispersing the solution in a ceramic raw material slip.
• the plasticizers include dioctyl phthalate (DOP), bis(2-ethylhexyl phthalate; DEHP), and dibutyl phthalate (DOP), which have good compatibility with the binder.
• DOP dioctyl phthalate
• DEHP bis(2-ethylhexyl phthalate
• DOP dibutyl phthalate
• Phthalic acid esters such as DBP
• phosphoric acid esters phosphoric acid esters
• fatty acid esters etc.
• the elastic sheets 24a and 24b may be silicone rubber sheets.
• the thickness of the elastic sheets 24a, 24b may be about 0.5 mm.
• the elastic sheet 24a on which the element body precursor 13 is placed via the support sheet 18 is moved toward the elastic sheet 24b on which the green sheet 14 is placed, and cut.
• the surface (first side surface 9a) is pressed against the green sheet 14.
• the pressing force may be, for example, about 30 kg/cm 2 to 100 kg/cm 2 .
• the pressability of the element body precursor 13 may be improved by heating the element body precursor 13 during pressing. In this case, since the pressing force can be reduced, pressing deformation of the element body precursor 13 can be suppressed.
• FIG. 13C shows a state in which the element body precursor 13 to which the green sheet 14 is crimped is moved upward. As shown in FIG. 13C, the portion of the green sheet 14 that is not in contact with the first side surface 9a remains on the resin sheet 27, so that the green sheet 14 can be attached to the first side surface 9a. The green sheet 14 can be attached to the second side surface 9b in the same manner as the steps shown in FIGS. 13A, 13B, and 13C.
• FIG. 14 shows the element body part 2 before firing, and a green sheet 14 serving as the protective layer 6 is attached to the first side surface 9a and the second side surface 9b.
• barrel polishing is performed on the fired element body part 2. Barrel polishing is performed for the purpose of removing corners and burrs of the element body part 2, and known barrel polishing can be used.
• the base component 2 is placed in a pot containing an abrasive and water and rotated.
• a conductive paste that will become the base layer of the external electrode 3 is printed and coated on the end surfaces 8a, 8b and main surfaces 7a, 7b of the element body precursor 13 of the element body component 2, and then baked to form the base layer of the external electrode 3. 3.
• Form the base layer Thereafter, by forming the plating outer layer of the external electrode 3, the multilayer ceramic capacitor 1 shown in FIG. 1 can be manufactured.
• the main component of the conductive paste serving as the base layer of the external electrode 3 may be Cu.
• the outer plating layer of the external electrode 3 may be a Ni plating layer, a Sn plating layer, or a Cu plating layer.
• the external electrode 3 may include a conductive resin such as an epoxy resin containing a conductive filler such as metal powder.
• FIG. 15 is a perspective view showing a laminated state of ceramic green sheets
• FIG. 16 is a perspective view showing a base laminate
• FIG. 17 is a perspective view showing an element body precursor
• FIG. 19 is a perspective view showing a plurality of element body precursors arranged on a support sheet
• FIG. 19 is a perspective view showing a multilayer ceramic capacitor.
• FIG. 20 is a perspective view showing the mother laminate.
• FIG. 21 is a perspective view showing a multilayer ceramic capacitor.
• the method for manufacturing a multilayer ceramic capacitor including the element body precursor 13 shown in FIG. 7A is the same as the manufacturing method described above, and therefore the description thereof will be omitted.
• multilayer ceramic capacitor 1A a multilayer ceramic capacitor including the element body precursor 13 shown in FIG. 7B
• the method for manufacturing the multilayer ceramic capacitor 1A is the same as the method for manufacturing the multilayer ceramic capacitor 1 up to the printing steps shown in FIGS. 8A, 8B, and 8C, so the explanation will be omitted.
• the lamination step of laminating the green sheets 10 on which the electrode layers 5 and 17 are printed the dummy electrode layer 17 is printed so that the first surface 7a of the laminate becomes the dummy electrode layer 17, as shown in FIG. Ceramic green sheets 10 for the second dielectric layer 16 are laminated. After producing the mother laminate 11 as shown in FIG.
• the mother laminate 11 is cut to obtain the element body precursor 13 shown in FIG.
• the element body precursor 13 is placed on the support sheet 18 with one of the first side surface 9a and the second side surface 9b (first side surface 9a) open.
• green sheets 14 for the protective layer 6 are attached to the side surfaces 9a and 9b.
• the element body part 2 is fired, barrel polishing is performed on the fired element body part 2 to chamfer the corners, and the electrode layer exposed on the end surfaces 8a, 8b and side surfaces 9a, 9b of the element body precursor 13
• the surface oxide films of Nos. 5 and 17 are removed.
• electroless Cu plating is applied to the end surfaces 8a and 8b of the element body part 2, and a continuous base layer is formed using the exposed portions of the electrode layers 5 and 17 as cores. Thereafter, by forming an electrolytic Ni plating layer and an electrolytic Sn plating layer on the surface of the base layer, thin external electrodes 3 as shown in FIG. 19 are located on the end surfaces 8a, 8b and the first surface 7a.
• a multilayer ceramic capacitor 1A can be manufactured.
• FIG. 20 shows the mother laminate 11 that is cut to become the element body precursor 13 shown in FIG. 7C.
• the first surface 7a and the second surface 7b are dummy electrode layers 17.
• the mother laminate 11 shown in FIG. 20 can be produced by printing the dummy electrode layer 17 on the lower surface of the mother laminate 11 shown in FIG. By cutting the base laminate 11 shown in FIG. 20, the element body precursor 13 shown in FIG. 7C is obtained.
• a multilayer ceramic capacitor having a thin external electrode 3 located from the end surfaces 8a and 8b to the first surface 7a and the second surface 7b as shown in FIG. Capacitor 1B can be manufactured.
• the mother laminate 11 shown in FIG. 20 may be produced by inverting the lower green sheet 10 in the lamination process shown in FIG. 15.
• the multilayer ceramic electronic component of the present disclosure can suppress a decrease in reliability even when the protective layer is made thin.
• the multilayer ceramic electronic component of the present disclosure can be implemented in the following configurations (1) to (8).
• a substantially rectangular parallelepiped-shaped laminated layer including an active part in which a plurality of first dielectric layers and internal electrode layers are alternately laminated in a predetermined direction, and covering parts located at both ends of the active part in the predetermined direction.
• a laminate having a first surface and a second surface facing each other in the predetermined direction, a first side surface and a second side surface facing each other, and a first end surface and a second end surface facing each other; a first external electrode located from the first end surface to at least one of the first surface and the second surface; a second external electrode located from the second end surface to the at least one of the first surface and the second surface; a protective layer having the same main component as the first dielectric layer, located on the first side surface and the second side surface, The first external electrode and the second external electrode are respectively connected to different internal electrode layers, The thickness of the protective layer is 30 ⁇ m or less,
• the covering portion includes a plurality of second dielectric layers having the same main component as the first dielectric layer and dummy
• the dummy electrode layer includes a first dummy electrode layer extending from the first end surface toward the second end surface, and a second dummy electrode layer extending from the second end surface toward the first end surface. death,
• the dummy electrode layer further includes at least one third dummy electrode layer, The at least one third dummy electrode layer is located between the first dummy electrode layer and the second dummy electrode layer, and is electrically insulated from the first dummy electrode layer and the second dummy electrode layer.
• the multilayer ceramic electronic component according to configuration (3) above.
• Multilayer ceramic electronic components multilayer ceramic capacitor
• Element body parts 3 External electrode 3a First external electrode 3b Second external electrode 4 First dielectric layer 5 Internal electrode layer 6 Protective layer 7a First surface 7b Second surface 8a First end surface 8b Second end surface 9a First side surface 9b second side surface 10 ceramic green sheet 11 base laminate 12 planned cutting line 13 laminate (element body precursor) 14 Ceramic green sheet 16 Second dielectric layer 17 Dummy electrode layer 17a First dummy electrode layer 17b Second dummy electrode layer 17c Third dummy electrode layer 18 Support sheet 19 Active part 20 Covering part 24a, 24b Elastic sheet 27 Resin sheet

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