JP2023025982A - Ceramic electronic component and circuit board - Google Patents

Abstract

To provide a ceramic electronic component in which mount detects hardly occur.SOLUTION: A ceramic electronic component includes: a ceramic element body; and first and second external electrode units. The ceramic element body includes: first and second main surfaces vertical to a first axis; first and second end surfaces vertical to a second axis orthogonal to the first axis; first and second side surfaces vertical to a third axis orthogonal to the first and second axes; and first and second ridge parts connecting respectively the first and second side surfaces to the first main surface. The first and second external electrode units are provided respectively on the first and second end surface sides of the ceramic element. The first and second external electrode units contain respectively: first and second terminal electrodes that coat the first and second end surfaces, and extend to the first main surface from the first and second end surfaces; and a pair of first and second auxiliary electrodes that is provided separated from the first and second terminal electrodes, as well as, mutually, extending in a third axis direction along the first main surface respectively from the first and second ridge parts.SELECTED DRAWING: Figure 1

Description

The present invention relates to a ceramic electronic component and a circuit board having a pair of terminal electrodes.

A laminated ceramic capacitor includes a ceramic body including a plurality of laminated internal electrodes, and a pair of external electrodes covering ends of the ceramic body. A multilayer ceramic capacitor is mounted by soldering a pair of external electrodes to a pair of terminals of a mounting substrate. A reflow method, for example, is used to mount the multilayer ceramic capacitor.

When mounting a multilayer ceramic capacitor, the solder wets and spreads on one of the pair of external electrodes first, and the surface tension of the solder acting on the one external electrode may cause the multilayer ceramic capacitor to rise (for example, , paragraph 0008 and FIG. 3 of Patent Document 1). This phenomenon is called the tombstone phenomenon.

On the other hand, in the multilayer ceramic capacitor described in Patent Document 1, the end faces of the external electrodes are configured to be less likely to protrude outward, thereby suppressing the occurrence of the tombstone phenomenon during mounting. Specifically, in this multilayer ceramic capacitor, by making the end faces of the ceramic body concave, the end faces of the external electrodes can be easily flattened.

JP-A-2000-49032

In recent years, multilayer ceramic capacitors have become smaller, thinner, and lighter as smartphones and wearable devices have become thinner, more multifunctional, and have larger battery capacities. On the other hand, it has been confirmed that the lighter the multilayer ceramic capacitor, the easier it is for the tombstone phenomenon to occur during mounting.

In multilayer ceramic capacitors, as weight reduction progresses, it will become more and more difficult to sufficiently prevent the occurrence of the tombstone phenomenon during mounting. Therefore, there is a demand for a technology capable of more effectively suppressing the occurrence of the tombstone phenomenon during mounting of multilayer ceramic capacitors.

SUMMARY OF THE INVENTION In view of the circumstances as described above, an object of the present invention is to provide a ceramic electronic component and a circuit board in which mounting defects are less likely to occur.

To achieve the above object, a ceramic electronic component according to one aspect of the present invention includes a ceramic body, a first external electrode unit, and a second external electrode unit.
The ceramic body has first and second main surfaces perpendicular to a first axis, first and second end surfaces perpendicular to a second axis perpendicular to the first axis, and first and second axes. It has first and second side surfaces perpendicular to a third orthogonal axis, and first and second ridges respectively connecting the first and second side surfaces to the first main surface.
The first external electrode unit is provided on the first end face side of the ceramic body. The first external electrode unit includes a first terminal electrode covering the first end surface and extending from the first end surface to the first main surface, separated from the first terminal electrode and separated from each other. a pair of first auxiliary electrodes provided along the first main surface and extending in the third axial direction from the first and second ridges, respectively.
The second external electrode unit is provided on the second end face side of the ceramic body. The second external electrode unit includes a second terminal electrode covering the second end surface and extending from the second end surface to the first main surface, separated from the second terminal electrode and separated from each other. a pair of second auxiliary electrodes provided along the first main surface from the first and second ridges, respectively, and extending in the third axial direction.

When mounting this ceramic electronic component, the first external electrode unit is soldered to the first terminal of the mounting board, and the second external electrode unit is soldered to the second terminal of the mounting board. In the ceramic electronic component during the mounting process, the surface tension of molten solder acts on the first external electrode unit on the first terminal and acts on the second external electrode unit on the second terminal.
In the first external electrode unit, a force acts on the first auxiliary electrode in a direction opposite to the force acting on the first terminal electrode, which causes the ceramic electronic component to rise above the first terminal. In addition, in the second external electrode unit, a force acts on the second auxiliary electrode in a direction opposite to the force acting on the second terminal electrode, which causes the ceramic electronic component to rise above the second terminal.
As a result, in the process of mounting the ceramic electronic component, even if molten solder wets and spreads prior to either one of the first and second external electrode units, the tombstone phenomenon occurs in which the ceramic electronic component rises. less likely to occur. Therefore, in this ceramic electronic component, it is possible to effectively suppress the occurrence of mounting defects.

The first terminal electrode, the pair of first auxiliary electrodes, the second terminal electrode, and the pair of second auxiliary electrodes may include a sintered film of a conductor.

The pair of first auxiliary electrodes may extend in the first axial direction along the first and second side surfaces from the first and second ridges, respectively.
The pair of second auxiliary electrodes may extend in the first axial direction along the first and second side surfaces from the first and second ridges, respectively.

The dimension of the pair of first auxiliary electrodes in the second axial direction may be 2% or more and 10% or less of the dimension of the first terminal electrode in the second axial direction.
The dimension of the pair of second auxiliary electrodes in the second axial direction may be 2% or more and 10% or less of the dimension of the second terminal electrode in the second axial direction.

The distance between the first terminal electrode and the pair of first auxiliary electrodes may be 2% or more and 10% or less of the dimension of the first terminal electrode in the second axial direction.
The distance between the second terminal electrode and the pair of second auxiliary electrodes may be 2% or more and 10% or less of the dimension of the second terminal electrode in the second axial direction.

A circuit board according to one aspect of the present invention includes a ceramic electronic component and a mounting board.
The ceramic electronic component includes a ceramic body, a first external electrode unit, and a second external electrode unit.
The ceramic body has first and second main surfaces perpendicular to a first axis, first and second end surfaces perpendicular to a second axis perpendicular to the first axis, and first and second axes. It has first and second side surfaces perpendicular to a third orthogonal axis, and first and second ridges respectively connecting the first and second side surfaces to the first main surface.
The first external electrode unit is provided on the first end face side of the ceramic body. The first external electrode unit includes a first terminal electrode covering the first end surface and extending from the first end surface to the first main surface, separated from the first terminal electrode and separated from each other. a pair of first auxiliary electrodes provided along the first main surface and extending in the third axial direction from the first and second ridges, respectively.
The second external electrode unit is provided on the second end face side of the ceramic body. The second external electrode unit includes a second terminal electrode covering the second end surface and extending from the second end surface to the first main surface, separated from the second terminal electrode and separated from each other. a pair of second auxiliary electrodes provided along the first main surface from the first and second ridges, respectively, and extending in the third axial direction.
The mounting board comprises a board body, a first terminal provided on the board body to which the first terminal electrode and the first auxiliary electrode are soldered, and a second terminal provided on the board body. an electrode and a second terminal to which the second auxiliary electrode is soldered.

According to the present invention, it is possible to provide a ceramic electronic component and a circuit board in which mounting defects are less likely to occur.

1 is a perspective view of a laminated ceramic capacitor according to one embodiment of the present invention; FIG. FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line AA' in FIG. 1; 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line BB' of FIG. 1; FIG. 2 is a plan view of the laminated ceramic capacitor; FIG. FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor taken along line CC' of FIG. 1; FIG. 2 is a side view of a circuit board on which the laminated ceramic capacitor is mounted; It is a side view which shows the process of mounting of the comparative example of the said laminated ceramic capacitor. 2 is a plan view of the laminated ceramic capacitor; FIG.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
The drawing shows mutually orthogonal X-, Y-, and Z-axes. The X-axis, Y-axis, and Z-axis are common in all drawings.

[Overall Configuration of Multilayer Ceramic Capacitor 10]
1 to 3 are diagrams showing a multilayer ceramic capacitor 10 according to one embodiment of the present invention. FIG. 1 is a perspective view of a laminated ceramic capacitor 10. FIG. FIG. 2 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line AA' in FIG. FIG. 3 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line BB' of FIG.

The multilayer ceramic capacitor 10 includes a ceramic element body 11, first terminal electrodes 14a, and second terminal electrodes 15a. The ceramic body 11 is configured as the main body of the laminated ceramic capacitor 10 . The terminal electrodes 14a and 15a constitute a pair of terminals for receiving electrical connection in the multilayer ceramic capacitor 10. As shown in FIG.

The ceramic body 11 has first and second end faces E1 and E2 perpendicular to the X-axis, first and second side faces S1 and S2 perpendicular to the Y-axis, and first and second principal faces perpendicular to the Z-axis. It is configured as a hexahedron having outer surfaces including M1, M2. The end faces E1, E2, the side faces S1, S2, and the main faces M1, M2 of the ceramic body 11 are all flat faces.

The flat surface according to the present embodiment does not have to be strictly a flat surface as long as it is recognized as flat when viewed as a whole. It also includes surfaces that have a gently curved shape, etc. The end surfaces E1, E2, the side surfaces S1, S2, and the principal surfaces M1, M2 may be partially perpendicular to the X, Y, and Z axes.

The ceramic body 11 has first and second ridges R1 and R2 extending along the X-axis. The first edge portion R1 connects the first side surface S1 and the first main surface M1, and the second edge portion R2 connects the second side surface S2 and the first main surface M1. It is preferable that the ceramic body 11 is chamfered so that the ridges R1 and R2 have rounded curved surfaces.

In the ceramic body 11, the first main surface M1 constitutes the lower surface in the Z-axis direction facing the mounting substrate during mounting. In addition, in the ceramic body 11, the second main surface M2 constitutes the upper surface in the Z-axis direction, that is, the second main surface M2 is held by suction during mounting. 1 shows the multilayer ceramic capacitor 10 from the first main surface M1 side of the ceramic body 11. FIG.

The first and second terminal electrodes 14a and 15a cover the first and second end faces E1 and E2 of the ceramic body 11 and face each other in the X-axis direction with the ceramic body 11 interposed therebetween. The terminal electrodes 14a and 15a extend from the respective end faces E1 and E2 of the ceramic body 11 to the main faces M1 and M2 and the side faces S1 and S2, and are spaced apart in the X-axis direction on the main faces M1 and M2 and the side faces S1 and S2. ing.

The ceramic body 11 is made of dielectric ceramics. The ceramic body 11 has a plurality of first internal electrodes 12 and second internal electrodes 13 covered with dielectric ceramics. The plurality of internal electrodes 12 and 13 are sheet-shaped and extend along the XY plane, and are alternately arranged along the Z-axis direction.

In other words, the ceramic body 11 has opposing regions in which the internal electrodes 12 and 13 face each other in the Z-axis direction with the ceramic layers interposed therebetween. The first internal electrode 12 is drawn out from the opposing region to the first end surface E1 and connected to the first terminal electrode 14a. The second internal electrode 13 is drawn out from the opposing region to the second end face E2 and connected to the second terminal electrode 15a.

With such a configuration, in the multilayer ceramic capacitor 10, when a voltage is applied between the first terminal electrode 14a and the second terminal electrode 15a, voltage is applied to the plurality of ceramic layers in the opposing regions of the internal electrodes 12 and 13. Join. As a result, in the multilayer ceramic capacitor 10, an electric charge corresponding to the voltage between the first terminal electrode 14a and the second terminal electrode 15a is stored.

In the ceramic body 11, dielectric ceramics with a high dielectric constant are used in order to increase the capacitance of each ceramic layer between the internal electrodes 12,13. Dielectric ceramics with a high dielectric constant include, for example, perovskite structure materials containing barium (Ba) and titanium (Ti), represented by barium titanate (BaTiO ₃ ).

Dielectric ceramics include strontium titanate (SrTiO ₃ ), calcium titanate (CaTiO ₃ ), magnesium titanate (MgTiO ₃ ), calcium zirconate (CaZrO 3 ), calcium zirconate titanate (Ca(Zr,Ti) O ₃ ), barium zirconate (BaZrO ₃ ), titanium oxide (TiO ₂ ), barium strontium titanate, barium calcium titanate, barium zirconate, barium zirconate titanate, calcium zirconate titanate, and zirconate titanate. It may be a composition system such as barium calcium (Ba _1-xy Ca _x Sr _y Ti _1-z Zr _z O ₃ ).

In the multilayer ceramic capacitor 10, the first terminal electrodes 14a are configured as part of the first external electrode unit 14 provided on the outer surface of the ceramic body 11 on the side of the first end surface E1. The second terminal electrode 15a is configured as part of the second external electrode unit 15 provided on the outer surface of the ceramic body 11 on the side of the second end face E2.

The first external electrode unit 14 includes a pair of first auxiliary electrodes 14b in addition to the first terminal electrodes 14a. The second external electrode unit 15 includes a pair of second auxiliary electrodes 15b in addition to the second terminal electrodes 15a. The auxiliary electrodes 14b and 15b are electrodes that do not function as terminals of the multilayer ceramic capacitor 10, unlike the terminal electrodes 14a and 15a.

The external electrode units 14 and 15 can be configured as sintered films of conductors. The sintered conductor films constituting the external electrode units 14 and 15 are formed by baking a conductive paste applied to the outer surface of the ceramic body 11 at positions corresponding to the terminal electrodes 14a and 15a and the auxiliary electrodes 14b and 15b. be able to.

The conductor forming the sintered film is typically composed mainly of Ni (nickel). However, the main component of the conductor forming the sintered film may be other than this, such as Cu (copper), Pd (palladium), Ag (silver), and the like. In addition, in this embodiment, the main component shall mean the component with the highest content ratio.

The external electrode units 14 and 15 may have a single-layer structure composed of a single layer or a multi-layer structure composed of a plurality of layers. For example, the external electrode units 14 and 15 may be provided with a conductive plated layer formed by wet plating on a base layer made of a sintered film of a conductor.

The plated layers forming the external electrode units 14 and 15 may have a single-layer structure made up of a single plated film, or a laminated structure made up of a plurality of plated films. As an example, the plated layer may have a laminated structure in which a Cu (copper) film, a Ni (nickel) film, and a Sn (tin) film are laminated in this order on the underlying layer.

The multilayer ceramic capacitor 10 can effectively suppress the occurrence of mounting defects due to the tombstone phenomenon due to the action of the auxiliary electrodes 14b and 15b. In particular, the multilayer ceramic capacitor 10 can more effectively prevent the occurrence of defective mounting even in a compact and lightweight configuration in which the tombstone phenomenon is more likely to occur during mounting.

Specifically, in the multilayer ceramic capacitor 10, the effect of suppressing the occurrence of defective mounting can be obtained more effectively when the size is 2.0±0.15 mm×1.2±0.15 mm×1.2±0.15 mm or less. easy to get That is, the effect of suppressing mounting defects is more effectively obtained when the dimension in the X-axis direction is 2.0 mm or less and the dimension in the Y-axis and Z-axis directions is 1.2 mm or less.

The size of the laminated ceramic capacitor 10 is, for example, 1.0±0.10 mm×0.5±0.10 mm×0.5±0.10 mm, 0.6±0.05 mm×0.3±0.05 mm× It can be 0.3±0.05 mm, 0.2±0.015 mm×0.1±0.015 mm×0.1±0.015 mm, and the like. The size of the multilayer ceramic capacitor 10 is not limited to these sizes, and various sizes can be used depending on the application.

[Auxiliary electrodes 14b, 15b]
4 is a plan view showing the laminated ceramic capacitor 10 from the first main surface M1 side of the ceramic body 11. FIG. FIG. 5 is a cross-sectional view of the multilayer ceramic capacitor 10 taken along line CC' of FIG. That is, FIG. 5 shows a cross section through one of the auxiliary electrodes 14b, 15b in the multilayer ceramic capacitor 10. As shown in FIG.

In the first external electrode unit 14, a pair of first auxiliary electrodes 14b are provided at positions adjacent to the first terminal electrodes 14a on the ridges R1 and R2, respectively. Both of the pair of first auxiliary electrodes 14b are separated from the first terminal electrode 14a in the X-axis direction. Also, the pair of first auxiliary electrodes 14b are opposed to each other with a gap in the Y-axis direction.

The pair of first auxiliary electrodes 14b respectively extend from the ridges R1 and R2 toward the central portion in the Y-axis direction along the first main surface M1. Also, the pair of first auxiliary electrodes 14b extend upward in the Z-axis direction along the side surfaces S1 and S2 from the ridges R1 and R2, respectively. As a result, each first auxiliary electrode 14b has an L-shaped cross section parallel to the YZ plane.

In the second external electrode unit 15, a pair of second auxiliary electrodes 15b are provided at positions adjacent to the second terminal electrodes 15a on the ridges R1 and R2, respectively. Both of the pair of second auxiliary electrodes 15b are separated from the second terminal electrode 15a in the X-axis direction. Also, the pair of second auxiliary electrodes 15b are opposed to each other with a gap in the Y-axis direction.

The pair of second auxiliary electrodes 15b respectively extend from the ridges R1 and R2 along the first main surface M1 toward the central portion in the Y-axis direction. Also, the pair of second auxiliary electrodes 15b extend upward in the Z-axis direction along the side surfaces S1 and S2 from the ridges R1 and R2, respectively. As a result, each second auxiliary electrode 15b has an L-shaped cross section parallel to the YZ plane.

FIG. 6 is a side view showing the circuit board 100 on which the multilayer ceramic capacitor 10 is mounted. The circuit board 100 includes a mounting board 20 having a board body 21 , first terminals 22 , and second terminals 23 . The terminals 22 and 23 constitute a pair of terminals of the mounting board 20 and are provided on the mounting surface of the board body 21 facing upward in the Z-axis direction.

In the circuit board 100, the external electrode units 14, 15 of the multilayer ceramic capacitor 10 are soldered to the terminals 22, 23 of the mounting board 20, respectively. Thereby, in the circuit board 100 , the multilayer ceramic capacitor 10 is electrically connected to the mounting board 20 and physically fixed.

A general reflow method can be used to mount the multilayer ceramic capacitor 10 on the mounting substrate 20 . In the reflow method, the external electrode units 14 and 15 of the multilayer ceramic capacitor 10 are placed on the terminals 22 and 23 of the mounting board 20 on which the solder H is arranged, and the solder H is melted in the process of passing through a reflow furnace. solidify after

As a result, on the first terminal 22 of the mounting board 20, the melted solder H substantially simultaneously wets and spreads the first terminal electrode 14a and the first auxiliary electrode 14b that are adjacent to each other. In addition, on the second terminal 23 of the mounting substrate 20, the melted solder H substantially simultaneously wets and spreads the second terminal electrode 15a and the second auxiliary electrode 15b that are adjacent to each other.

Thus, in the multilayer ceramic capacitor 10, the terminal electrodes 14a, 15a and the auxiliary electrodes 14b, 15b can be soldered to the terminals 22, 23 collectively. Therefore, in the multilayer ceramic capacitor 10, additional labor is not required for soldering the auxiliary electrodes 14b, 15b to the terminals 22, 23 of the mounting board 20. FIG.

In the multilayer ceramic capacitor 10, by providing the auxiliary electrodes 14b and 15b, it is possible to suppress the occurrence of the tombstone phenomenon, which rises at one of the terminals 22 and 23 due to the surface tension of the solder H in the molten state. The function of the auxiliary electrodes 14b and 15b in the multilayer ceramic capacitor 10 will be described below.

FIG. 7 is a side view showing a process of mounting a laminated ceramic capacitor 10a according to a comparative example of this embodiment. The multilayer ceramic capacitor 10a according to the comparative example is different from the multilayer ceramic capacitor 10 according to the present embodiment in that although terminal electrodes 14a and 15a are provided, auxiliary electrodes 14b and 15b are not provided.

A tombstone phenomenon that rises above the second terminal 23 of the mounting substrate 20 occurs in the multilayer ceramic capacitor 10a shown in FIG. This tombstone phenomenon is caused by the action of the surface tension of the solder H that wets and spreads on the second terminal electrode 15a prior to the first terminal electrode 14a, thereby generating a moment in the direction indicated by the arrow in FIG. .

In the multilayer ceramic capacitor 10a shown in FIG. 7, the tombstone phenomenon causes the first terminal electrode 14a to rise from the first terminal 22 of the mounting substrate 20, and thus the first terminal 22 of the mounting substrate 20 at the first terminal electrode 14a. continuity to the Therefore, the multilayer ceramic capacitor 10a shown in FIG. 7 becomes defective in mounting.

Further, in the multilayer ceramic capacitor 10a, even when the solder H wets and spreads on the first terminal electrodes 14a prior to the second terminal electrodes 15a, the tombstone phenomenon occurs on the first terminals 22 of the mounting substrate 20. . As described above, in the multilayer ceramic capacitor 10a according to the comparative example, mounting defects due to the tombstone phenomenon are likely to occur.

In contrast, in the multilayer ceramic capacitor 10 according to the present embodiment, the surface tension of the solder H acts to prevent the auxiliary electrodes 14b and 15b from standing up on the terminals 22 and 23 of the mounting board 20. . Thereby, in the multilayer ceramic capacitor 10, the occurrence of the tombstone phenomenon can be suppressed.

That is, in the first external electrode unit 14, the surface tension of the solder H causes the multilayer ceramic capacitor 10 acting on the first terminal electrode 14a to rise above the first terminal 22 against the first auxiliary electrode 14b. Acts in the opposite direction to force. This makes it difficult for the multilayer ceramic capacitor 10 to rise on the first terminal 22 .

Further, in the second external electrode unit 15, the surface tension of the solder H causes the multilayer ceramic capacitor 10 acting on the second terminal electrode 15a to rise on the second terminal 23 against the second auxiliary electrode 15b. Acts in the opposite direction to force. This makes it difficult for the multilayer ceramic capacitor 10 to rise on the second terminal 23 .

Therefore, in the multilayer ceramic capacitor 10, even when the solder H wets and spreads prior to one of the external electrode units 14 and 15, the tombstone phenomenon is less likely to occur. Easy to maintain posture. Therefore, the multilayer ceramic capacitor 10 can suppress the occurrence of mounting defects.

In the multilayer ceramic capacitor 10, by providing the auxiliary electrodes 14b and 15b separately from the terminal electrodes 14a and 15a, the effect of the surface tension of the solder H applied to the auxiliary electrodes 14b and 15b can be stably obtained. As a result, the multilayer ceramic capacitor 10 can more effectively suppress the occurrence of the tombstone phenomenon.

Further, as shown in FIG. 8, in the multilayer ceramic capacitor 10, the portions of the terminal electrodes 14a and 15a that extend above the first main surface M1 have a shape that bulges inward in the X-axis direction at the central portion in the Y-axis direction. Prone. This is due to fluidity of the conductive paste on the ceramic body 11 for forming the terminal electrodes 14a and 15a.

That is, on the outer surface of the ceramic body 11, the fluidity of the conductive paste in the X-axis direction is higher at the center portion of the first main surface M1 in the Y-axis direction than at the ridges R1 and R2. As a result, the terminal electrodes 14a and 15a extend more than the ridges R1 and R2 at the central portion of the first main surface M1 in the Y-axis direction, and thus tend to have the bulging shape as described above.

In this regard, in the multilayer ceramic capacitor 10, the auxiliary electrodes 14b, 15b are provided only at four locations near the ridges R1, R2 where the terminal electrodes 14a, 15a on the outer surface of the ceramic body 11 extend inward in the X-axis direction by a small amount. set up. Therefore, in the multilayer ceramic capacitor 10, the auxiliary electrodes 14b and 15b can be arranged closer to the end surfaces E1 and E2.

Therefore, in the multilayer ceramic capacitor 10, the distance between the auxiliary electrodes 14b and 15b in the X-axis direction can be increased by the amount of the auxiliary electrodes 14b and 15b moved toward the end faces E1 and E2. As a result, in the multilayer ceramic capacitor 10, it is possible to suppress the occurrence of poor moisture resistance due to migration between the auxiliary electrodes 14b and 15b.

Further, in the multilayer ceramic capacitor 10, the auxiliary electrodes 14b, 15b can be miniaturized by providing the auxiliary electrodes 14b, 15b only at four locations near the ridges R1, R2. Therefore, the area to which the conductive paste is applied when forming the external electrode units 14 and 15 on the outer surface of the ceramic body 11 can be reduced.

Therefore, even in the process of handling a plurality of ceramic bodies 11 at the same time, such as firing for baking the conductive paste, it is possible to reduce the probability that the conductive pastes of adjacent ceramic bodies 11 come into contact with each other. As a result, it is possible to suppress the occurrence of adhesion failures in which the external electrode units 14 and 15 of the plurality of laminated ceramic capacitors 10 adhere to each other.

In the multilayer ceramic capacitor 10, even when the auxiliary electrodes 14b and 15b are small, the auxiliary electrodes 14b and 15b extend from the ridges R1 and R2 to the first main surface M1 and the side surfaces S1 and S2. It is possible to sufficiently and accurately obtain the above-described action on the auxiliary electrodes 14b and 15b by the surface tension of .

[Dimensions of External Electrode Units 14 and 15]
4 and 5 show the following dimensions of the external electrode units 14 and 15. "L0" indicates the length of each terminal electrode 14a, 15a in the X-axis direction. "W0" indicates the width of each terminal electrode 14a, 15a in the Y-axis direction. "T0" indicates the thickness of each terminal electrode 14a, 15a on the first main surface M1 in the Z-axis direction.

"L" indicates the length of each auxiliary electrode 14b, 15b in each external electrode unit 14, 15 in the X-axis direction. "W" indicates the width of each auxiliary electrode 14b, 15b in each external electrode unit 14, 15 in the Y-axis direction. "T" indicates the thickness of each auxiliary electrode 14b, 15b in each external electrode unit 14, 15 on the first main surface M1 in the Z-axis direction.

Furthermore, "D1" indicates the distance in the X-axis direction between the first auxiliary electrode 14b and the second auxiliary electrode 15b. "D2" indicates the distance between the terminal electrodes 14a, 15a and the auxiliary electrodes 14b, 15b in the external electrode units 14, 15 in the X-axis direction. "D3" indicates the distance in the Y-axis direction between the first auxiliary electrodes 14b and between the second auxiliary electrodes 15b.

In addition, in the multilayer ceramic capacitor 10, it is conceivable that the above dimensions may not be constant over the entire range. In this case, the lengths L0 and L, the widths W0 and W, and the thicknesses T0 and T are defined as the maximum values of the respective dimensions. Also, the intervals D1, D2, and D3 are defined as the minimum values of the respective dimensions.

The distance D1 in the X-axis direction between the auxiliary electrodes 14b and 15b is preferably 160% or more of the dimension L0 in the X-axis direction between the terminal electrodes 14a and 15a. As a result, in the multilayer ceramic capacitor 10, it is possible to more effectively prevent the occurrence of poor moisture resistance due to migration between the auxiliary electrodes 14b and 15b.

The distance D2 in the X-axis direction between the terminal electrodes 14a, 15a and the auxiliary electrodes 14b, 15b in each of the external electrode units 14, 15 is preferably 2% or more of the dimension L0 of the terminal electrodes 14a, 15a in the X-axis direction. . This makes it possible for the auxiliary electrodes 14b and 15b to receive the action of the surface tension of the solder H more stably.

Also, the distance D2 in the X-axis direction between the terminal electrodes 14a, 15a and the auxiliary electrodes 14b, 15b in each of the external electrode units 14, 15 should be 10% or less of the dimension L0 of the terminal electrodes 14a, 15a in the X-axis direction. is preferred. This makes it easier to collectively solder the terminal electrodes 14a and 15a and the auxiliary electrodes 14b and 15b to the terminals 22 and 23 of the mounting substrate 20 .

The distance D3 in the Y-axis direction between the auxiliary electrodes 14b and 15b in each of the external electrode units 14 and 15 is preferably 40% or more of the Y-axis dimension W0 of the terminal electrodes 14a and 15a. As a result, the auxiliary electrodes 14b and 15b can be arranged closer to the end surfaces E1 and E2.

In each of the external electrode units 14 and 15, the length L in the X-axis direction of each auxiliary electrode 14b and 15b is preferably 2% or more of the length L0 in the X-axis direction of the terminal electrodes 14a and 15a. This makes it possible for the auxiliary electrodes 14b and 15b to receive the action of the surface tension of the solder H more effectively.

In each of the external electrode units 14 and 15, the X-axis length L of each auxiliary electrode 14b and 15b is preferably 10% or less of the X-axis length L0 of the terminal electrodes 14a and 15a. This makes it easier to ensure a large distance D1 between the auxiliary electrodes 14b and 15b in the X-axis direction, and the size of the auxiliary electrodes 14b and 15b can be reduced.

In each external electrode unit 14, 15, the width W of each auxiliary electrode 14b, 15b in the Y-axis direction is preferably 1% or more of the width W0 of the terminal electrode 14a, 15a in the Y-axis direction. This makes it possible for the auxiliary electrodes 14b and 15b to receive the action of the surface tension of the solder H more effectively.

Further, in each of the external electrode units 14 and 15, the width W of each of the auxiliary electrodes 14b and 15b in the Y-axis direction should be 100 μm or less, and should be 10% or less of the width W0 of the terminal electrodes 14a and 15a in the Y-axis direction. is preferred. As a result, the auxiliary electrodes 14b and 15b can be arranged closer to the end surfaces E1 and E2, and the size of the auxiliary electrodes 14b and 15b can be reduced.

In each external electrode unit 14, 15, the thickness T of the auxiliary electrodes 14b, 15b in the Z-axis direction is preferably 10% or more and 100% or less of the thickness T0 of the terminal electrodes 14a, 15a in the Z-axis direction. This makes it easier to collectively solder the terminal electrodes 14a and 15a and the auxiliary electrodes 14b and 15b to the terminals 22 and 23 of the mounting substrate 20 .

[Examples and Comparative Examples]
As an example of the above-described embodiment, samples of the multilayer ceramic capacitor 10 having various dimensions of the external electrode units 14 and 15 were produced. Also, as a comparative example of the above embodiment, a sample was produced in which the auxiliary electrodes 14b and 15b were removed from the multilayer ceramic capacitor 10 according to the above embodiment.

The samples according to the examples and the comparative examples each had a dimension in the X-axis direction of 2.0 mm and a dimension in the Y-axis and Z-axis directions of 1.2 mm. In both the samples according to the example and the comparative example, the length L0 of the terminal electrodes 14a and 15a in the X-axis direction was set to 0.52 mm, and the width W0 of the terminal electrodes 14a and 15a in the Y-axis direction was set to 1.2 mm. bottom.

In each of the examples and the comparative examples, the bad adhesion rate, which is the ratio of defective adhesion samples in which the external electrode units 14 and 15 are adhered to each other, is calculated by baking the conductive paste on the plurality of ceramic bodies 11 at once. asked. In each of the examples and comparative examples, 10,000 samples were collectively fired to determine the adhesion failure rate.

Further, in each example and comparative example, when a plurality of normally manufactured samples were mounted on the mounting substrate 20 by the reflow method, the mounting defect rate, which is the ratio of the samples in which the tombstone phenomenon occurred, was obtained. In each example and comparative example, the mounting defect rate was obtained by mounting 800 samples on the mounting board 20, respectively.

Furthermore, in each of the examples and comparative examples, among the plurality of circuit boards on which the samples were normally mounted, the electrical resistance value after being held at a temperature of 60 ° C., a humidity of 95%, and a rated voltage of 10 V was applied was less than 1 MΩ. A moisture resistance defect rate, which is the ratio of the circuit board that becomes In each example and comparative example, 800 circuit boards were used to determine the humidity defect rate.

Table 1 shows the dimensions of the external electrode units 14 and 15, the adhesion failure rate, the mounting failure rate, and the humidity resistance failure rate for Examples 1 to 5 and the comparative example. In the samples according to Examples 1 to 5, the length L of the auxiliary electrodes 14b and 15b in the X-axis direction is varied, that is, the ratio of the length L1 to the length L0 is different.

Adhesion failure did not occur in any of Examples 1 to 5 and Comparative Example. Also, while no mounting failure occurred in any of Examples 1 to 5, mounting failure occurred in the comparative example. Further, in Examples 1 to 3 and Comparative Example, no poor humidity resistance occurred, whereas in Examples 4 and 5, poor humidity resistance occurred.

From the result of the mounting defect rate, it can be seen that the occurrence of the tombstone phenomenon was suppressed in Examples 1 to 5 in which the auxiliary electrodes 14b and 15b were provided, as compared with the comparative example. In addition, from the results of the moisture resistance defect rate, in Examples 1 to 3 in which the ratio of length L1 to length L0 is 10% or less, the ratio of length L1 to length L0 exceeds 10% than Examples 4 and 5 It can be seen that the moisture resistance is high.

Table 2 shows the dimensions of the external electrode units 14 and 15, the adhesion defect rate, the mounting defect rate, and the moisture resistance defect rate for Examples 2, 6, and 7. In Examples 2, 6, and 7, the width W of the auxiliary electrodes 14b and 15b in the Y-axis direction was variously changed, but in any case, poor adhesion, poor mounting, and poor moisture resistance did not occur.

[Other embodiments]
Although the embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and can be modified in various ways.

For example, in the multilayer ceramic capacitor 10, the auxiliary electrodes 14b and 15b are not limited to being provided only on the first principal surface M1, and may be provided on both the principal surfaces M1 and M2. As a result, when mounting the multilayer ceramic capacitor 10 on the mounting substrate 20, it is not necessary to consider the orientation of the multilayer ceramic capacitor 10 in the Z-axis direction.

Moreover, in the multilayer ceramic capacitor 10, the terminal electrodes 14a and 15a only need to extend to the first main surface M1. 15a may not extend to the second main surface M2. Moreover, the terminal electrodes 14a and 15a may not extend to the side surfaces S1 and S2.

Furthermore, the external electrode units 14 and 15 may not include a conductor sintered film, and may include, for example, a sputtered film formed by sputtering a metal material as a base film. In this case as well, in the multilayer ceramic capacitor 10, the effect of suppressing the occurrence of the tombstone phenomenon due to the auxiliary electrodes 14b and 15b can be obtained.

In addition, the present invention can be applied not only to laminated ceramic capacitors but also to ceramic electronic components in general having a structure with a pair of terminal electrodes. Ceramic electronic components to which the present invention can be applied include, for example, chip varistors, chip thermistors, laminated inductors, etc., in addition to laminated ceramic capacitors.

DESCRIPTION OF SYMBOLS 10... Laminated ceramic capacitor 11... Ceramic element body 12, 13... Internal electrodes 14, 15... External electrode units 14a, 15a... Terminal electrodes 14b, 15b... Auxiliary electrodes E1, E2... End faces S1, S2... Side faces M1, M2... Main Surfaces R1, R2... ridges

Claims (6)

First and second principal surfaces perpendicular to the first axis, first and second end surfaces perpendicular to the second axis perpendicular to the first axis, and a third axis perpendicular to the first and second axes a ceramic body having first and second vertical side surfaces and first and second ridges respectively connecting the first and second side surfaces to the first main surface;
a first external electrode unit provided on the first end face side of the ceramic body;
a second external electrode unit provided on the second end face side of the ceramic body;
and
The first external electrode unit includes a first terminal electrode covering the first end surface and extending from the first end surface to the first main surface, and a first terminal electrode separated from the first terminal electrode and separated from each other. a pair of first auxiliary electrodes provided along the first main surface and extending in the third axial direction from the first and second ridges, respectively, wherein the second external electrode unit includes the second a second terminal electrode covering the end surface and extending from the second end surface to the first main surface; a pair of second auxiliary electrodes each extending in the third axial direction along the first main surface from the ceramic electronic component. The ceramic electronic component according to claim 1,
The first terminal electrode, the pair of first auxiliary electrodes, the second terminal electrode, and the pair of second auxiliary electrodes each include a sintered conductive film. The ceramic electronic component according to claim 1 or 2,
the pair of first auxiliary electrodes extend in the first axial direction along the first and second side surfaces from the first and second ridges, respectively;
The pair of second auxiliary electrodes extend in the first axial direction along the first and second side surfaces from the first and second ridges, respectively. The ceramic electronic component according to any one of claims 1 to 3,
the dimension of the pair of first auxiliary electrodes in the second axial direction is 2% or more and 10% or less of the dimension of the first terminal electrode in the second axial direction;
The dimension of the pair of second auxiliary electrodes in the second axial direction is 2% or more and 10% or less of the dimension of the second terminal electrode in the second axial direction. The ceramic electronic component according to any one of claims 1 to 3,
the distance between the first terminal electrode and the pair of first auxiliary electrodes is 2% or more and 10% or less of the dimension of the first terminal electrode in the second axial direction;
A ceramic electronic component, wherein the distance between the second terminal electrode and the pair of second auxiliary electrodes is 2% or more and 10% or less of the dimension of the second terminal electrode in the second axial direction. First and second principal surfaces perpendicular to the first axis, first and second end surfaces perpendicular to the second axis perpendicular to the first axis, and a third axis perpendicular to the first and second axes a ceramic body having first and second vertical side surfaces and first and second ridges respectively connecting the first and second side surfaces to the first main surface;
a first external electrode unit provided on the first end face side of the ceramic body;
a second external electrode unit provided on the second end face side of the ceramic body;
with
The first external electrode unit includes a first terminal electrode covering the first end surface and extending from the first end surface to the first main surface, and a first terminal electrode separated from the first terminal electrode and separated from each other. a pair of first auxiliary electrodes provided along the first main surface and extending in the third axial direction from the first and second ridges, respectively, wherein the second external electrode unit includes the second a second terminal electrode covering the end surface and extending from the second end surface to the first main surface; a pair of second auxiliary electrodes each extending in the third axial direction along the first main surface from the ceramic electronic component;
a substrate main body; a first terminal provided on the substrate main body to which the first terminal electrode and the first auxiliary electrode are soldered; a mounting board having a second terminal to which an auxiliary electrode is soldered;
A circuit board comprising:

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