Layered ceramic electronic component mounting structure

Abstract

Provided is a layered ceramic electronic component mounting structure that suppresses a reduction in the stability of a mounting posture. A mounting structure 90 is a mounting structure in which a layered ceramic electronic component 1 is mounted on a circuit board CB. The layered ceramic electronic component 1 comprises: a layered body in which an inner conductor layer and a plurality of dielectric layers made of a ceramic material are layered; and a first outer electrode 41 and a second outer electrode 42 disposed on only two principal surfaces or on only one principal surface of the layered body. The circuit board CB comprises a first land electrode 51 and a second land electrode 52. An inside end of the first outer electrode 41 is positioned more toward the second outer electrode 42 side and the second land electrode 52 side than an inside end of the first land electrode 51, and an inside end of the second outer electrode 42 is positioned more toward the first outer electrode 41 side and the first land electrode 51 side than an inside end of the second land electrode 52.

Description

Mounting structure of multilayer ceramic electronic components

[0001] The present invention relates to a mounting structure for a multilayer ceramic electronic component.

[0002] Multilayer ceramic electronic components using ceramics are known as surface-mount electronic components. For example, Patent Document 1 discloses a multilayer ceramic capacitor as such a multilayer ceramic electronic component. This multilayer ceramic capacitor includes a laminate including a plurality of dielectric layers and a plurality of internal electrode layers (internal conductor layers) made of ceramic material stacked together, and two external electrodes disposed on two end faces of the laminate.

[0003] In a mounting structure in which such a multilayer ceramic electronic component is mounted on a circuit board, the external electrodes of the multilayer ceramic electronic component are connected to land electrodes of the circuit board. In such a mounting structure, fillets of paste solder are formed on the external electrodes on the end faces of the multilayer ceramic electronic component during the mounting process, thereby stabilizing the mounting posture of the multilayer ceramic electronic component.

[0004] JP 2016-76582 A

[0005] There is a demand for further miniaturization of such multilayer ceramic electronic components. Furthermore, there is a demand for higher density mounting in the mounting structure of such multilayer ceramic electronic components. From the viewpoint of high density mounting, it is conceivable to reduce the area occupied by fillets of paste solder formed on the external electrodes on the end faces of the multilayer ceramic electronic component. In this regard, it is conceivable to arrange the external electrodes not on the end faces of the multilayer ceramic electronic component but on the mounting surface of the multilayer ceramic electronic component.

[0006] However, according to the findings of the present inventors, in a multilayer ceramic electronic component that does not have external electrodes disposed on its end faces, a fillet of paste solder is not formed on the end faces of the multilayer ceramic electronic component during the mounting process of the multilayer ceramic electronic component, and therefore the mounting posture of the multilayer ceramic electronic component is unstable, and for example, the component may float and tilt. This decrease in the stability of the mounting posture can become more pronounced as the multilayer ceramic electronic component becomes smaller.

[0007] An object of the present invention is to provide a mounting structure for a multilayer ceramic electronic component that suppresses a decrease in the stability of the mounting posture.

[0008] A mounting structure for a multilayer ceramic electronic component according to the present invention is a mounting structure for a multilayer ceramic electronic component in which the multilayer ceramic electronic component is mounted on a circuit board. The multilayer ceramic electronic component is a laminate formed by stacking a plurality of dielectric layers and internal conductor layers made of ceramic material, the laminate having two main surfaces opposing each other in a thickness direction, two side surfaces opposing each other in a width direction intersecting the thickness direction, and two end faces opposing each other in a length direction intersecting the thickness direction and the width direction. First and second external electrodes are arranged on only the two main surfaces of the laminate or on only one of the two main surfaces of the laminate, spaced apart in the length direction. The circuit board is provided with first and second land electrodes spaced apart in the length direction and connected to the first and second external electrodes of the multilayer ceramic electronic component, respectively. An inner end of the first external electrode on the second external electrode side in the longitudinal direction is located closer to the second external electrode and the second land electrode than an inner end of the first land electrode on the second land electrode side in the longitudinal direction, and an inner end of the second external electrode on the first external electrode side in the longitudinal direction is located closer to the first external electrode and the first land electrode than an inner end of the second land electrode on the first land electrode side in the longitudinal direction.

[0009] According to the present invention, in a mounting structure for a multilayer ceramic electronic component, it is possible to suppress a decrease in stability of the mounting posture.

[0010] 1 is a perspective view showing a multilayer ceramic capacitor (multilayer ceramic electronic component) according to an embodiment of the present invention; FIG. 2 is a cross-sectional view (WT cross-section) taken along line II-II of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 1; FIG. 3 is a cross-sectional view (LT cross-section) taken along line IIIA-IIIA of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 2; FIG. 4 is a cross-sectional view (LT cross-section) taken along line IIIB-IIIB of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 2; FIG. 5 is a perspective view showing a mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to an embodiment of the present invention; FIG. 6 is a side view showing a mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to an embodiment of the present invention; FIG. 7 is a side view showing a mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to an embodiment of the present invention; FIG. 8 is a side view showing a mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to a comparative example; FIG. 9 is a side view showing a mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to a comparative example.

[0011] An example of an embodiment of the present invention will be described below with reference to the accompanying drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0012] <Multilayer Ceramic Capacitor: Multilayer Ceramic Electronic Component> FIG. 1 is a perspective view showing a multilayer ceramic capacitor (multilayer ceramic electronic component) according to this embodiment, and FIG. 2 is a cross-sectional view (WT cross-section) of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 1 taken along line II-II. FIG. 3A is a cross-sectional view (LT cross-section) of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 2 taken along line IIIA-IIIA. FIG. 3B is a cross-sectional view (LT cross-section) of the multilayer ceramic capacitor (multilayer ceramic electronic component) shown in FIG. 2 taken along line IIIB-IIIB. The multilayer ceramic capacitor (multilayer ceramic electronic component) 1 shown in FIGS. 1 to 3B includes a laminate 10 and two pairs of external electrodes 40. Each of the external electrodes 40 includes a first external electrode 41 and a second external electrode 42.

[0013] 1 to 3B and the drawings described below show an XYZ Cartesian coordinate system. The X direction is the length direction L of the multilayer ceramic capacitor 1 and the laminate 10, the Y direction is the width direction W of the multilayer ceramic capacitor 1 and the laminate 10, and the Z direction is the thickness direction T of the multilayer ceramic capacitor 1 and the laminate 10. Therefore, the cross section shown in FIG. 2 is also referred to as a WT cross section, and the cross sections shown in FIGS. 3A and 3B are also referred to as an LT cross section.

[0014] The length direction L, width direction W, and thickness direction T do not necessarily have to be perpendicular to each other, and may intersect each other.

[0015] The laminate 10 has an approximately rectangular parallelepiped shape and has a first main surface TS1 and a second main surface TS2 facing in the thickness direction T, a first side surface WS1 and a second side surface WS2 facing in the width direction W, and a first end surface LS1 and a second end surface LS2 facing in the length direction L.

[0016] It is preferable that the corners and ridges of the laminate 10 are rounded. A corner is a portion where three surfaces of the laminate 10 intersect, and a ridge is a portion where two surfaces of the laminate 10 intersect.

[0017] 2, 3A, and 3B, the laminate 10 has a plurality of dielectric layers 20 and a plurality of internal electrode layers 30 stacked in the width direction W. The laminate 10 also has, in the width direction W, i.e., the stacking direction, an inner layer portion 100, and a first outer layer portion 101 and a second outer layer portion 102 arranged to sandwich the inner layer portion 100.

[0018] The internal layer portion 100 includes some of the multiple dielectric layers 20 and multiple internal electrode layers (internal conductor layers) 30. In the internal layer portion 100, the multiple internal electrode layers 30 are arranged opposite each other with the dielectric layers 20 interposed therebetween. The internal layer portion 100 is a portion (effective region) that generates capacitance and essentially functions as a capacitor.

[0019] The first outer layer portion 101 is disposed on the first side surface WS1 side of the laminate 10, and the second outer layer portion 102 is disposed on the second side surface WS2 side of the laminate 10. More specifically, the first outer layer portion 101 is disposed between the first side surface WS1 and an internal electrode layer 30 of the plurality of internal electrode layers 30 that is closest to the first side surface WS1, and the second outer layer portion 102 is disposed between the second side surface WS2 and an internal electrode layer 30 of the plurality of internal electrode layers 30 that is closest to the second side surface WS2. The first outer layer portion 101 and the second outer layer portion 102 do not include the internal electrode layer 30, but each include a portion of the plurality of dielectric layers 20 other than the portion for the internal layer portion 100. The first outer layer portion 101 and the second outer layer portion 102 function as protective layers for the internal layer portion 100.

[0020] The material of the dielectric layer 20 is, for example, BaTiO ３ , CaTiO ３ , SrTiO ３ , or CaZrO ３ A dielectric ceramic containing, as a main component, a material such as a manganese compound, an iron compound, a chromium compound, a cobalt compound, or a nickel compound may be used. The material of the dielectric layer 20 may also contain, as a secondary component, a manganese compound, an iron compound, a chromium compound, a cobalt compound, or a nickel compound. More specifically, the dielectric layer 20 includes a plurality of dielectric grains. The dielectric grains are barium titanate-based ceramics such as perovskite-type compounds containing barium and titanium. The dielectric grains may also include, as a secondary component, at least one of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, and Y.

[0021] The thickness of the dielectric layers 20 is not particularly limited, but may be, for example, 0.40 μm or more and 1.0 μm or less. The number of dielectric layers 20 is also not particularly limited, but may be, for example, 10 to 1,000. Note that the number of dielectric layers 20 is the total number of the dielectric layers in the inner layer portion and the dielectric layers in the outer layer portion.

[0022] 2, 3A, and 3B, the multiple internal electrode layers 30 include multiple first internal electrode layers 31 and multiple second internal electrode layers 32. The multiple first internal electrode layers 31 and the multiple second internal electrode layers 32 are arranged alternately in the width direction W of the laminate 10, i.e., the stacking direction.

[0023] The first internal electrode layer 31 includes a counter electrode portion 311 and a lead electrode portion 312 , and the second internal electrode layer 32 includes a counter electrode portion 321 and a lead electrode portion 322 .

[0024] The opposing electrode portions 311 and 321 face each other across the dielectric layer 20 in the width direction T of the laminate 10, i.e., the stacking direction. The shapes of the opposing electrode portions 311 and 321 are not particularly limited and may be, for example, approximately rectangular. The opposing electrode portions 311 and 321 are portions (effective areas) that generate electrostatic capacitance and essentially function as capacitors.

[0025] The extraction electrode portion 312 extends from a portion of the counter electrode portion 311 on the first end surface LS1 side of the laminate 10 toward the first main surface TS1 of the laminate 10 and is exposed at the first main surface TS1. The extraction electrode portion 312 also extends from a portion of the counter electrode portion 311 on the first end surface LS1 side of the laminate 10 toward the second main surface TS2 of the laminate 10 and is exposed at the second main surface TS2. The extraction electrode portion 322 extends from a portion of the counter electrode portion 321 on the second end surface LS2 side of the laminate 10 toward the first main surface TS1 of the laminate 10 and is exposed at the first main surface TS1. The extraction electrode portion 322 extends from a portion of the counter electrode portion 321 on the second end surface LS2 side of the laminate 10 toward the second main surface TS2 of the laminate 10 and is exposed at the second main surface TS2. The shapes of the extraction electrode portion 312 and the extraction electrode portion 322 are not particularly limited, and may be, for example, substantially rectangular.

[0026] As a result, the first internal electrode layer 31 is connected to the first external electrodes 41 arranged on the first main surface TS1 and the second main surface TS2 of the laminate 10, and is spaced apart from the second external electrodes 42 arranged on the first main surface TS1 and the second main surface TS2 of the laminate 10. In addition, the second internal electrode layer 32 is connected to the second external electrodes 42 arranged on the first main surface TS1 and the second main surface TS2 of the laminate 10, and is spaced apart from the first external electrodes 41 arranged on the first main surface TS1 and the second main surface TS2 of the laminate 10.

[0027] The first internal electrode layer 31 and the second internal electrode layer 32 contain metal Ni as a main component. The first internal electrode layer 31 and the second internal electrode layer 32 may contain, as a main component, or as a component other than the main component, at least one selected from metals such as Cu, Ag, Pd, or Au, or alloys containing at least one of these metals, such as an Ag-Pd alloy. Furthermore, the first internal electrode layer 31 and the second internal electrode layer 32 may contain, as a component other than the main component, particles of a dielectric material having the same composition as the ceramic contained in the dielectric layer 20. In this specification, the metal of the main component is defined as the metal component with the highest weight percentage.

[0028] The thicknesses of the first internal electrode layers 31 and the second internal electrode layers 32 are not particularly limited, but may be, for example, 0.20 μm or more and 1.00 μm or less. The number of the first internal electrode layers 31 and the second internal electrode layers 32 is not particularly limited, but may be, for example, 10 or more and 1000 or less.

[0029] The dimensions of the laminate 10 described above are not particularly limited, but may be, for example, a length in the length direction L of 0.20 mm to 1.00 mm, a width in the width direction W of 0.10 mm to 0.50 mm, and a thickness in the thickness direction T of 0.10 mm to 0.50 mm. Furthermore, the dimensions of the multilayer ceramic capacitor 1 including external electrodes 40 described later are not particularly limited, but may be, for example, a length in the length direction L of 0.20 mm to 1.00 mm, a width in the width direction W of 0.10 mm to 0.50 mm, and a thickness in the thickness direction T of 0.10 mm to 0.50 mm.

[0030] The thicknesses of the dielectric layers 20 and the internal electrode layers 30 can be measured by, for example, observing a WT cross section of the laminate exposed by polishing near the center in the longitudinal direction with a scanning electron microscope. Each value may be an average value of measurements taken at multiple locations in the width direction, or may be an average value of measurements taken at multiple locations in the thickness direction.

[0031] Similarly, the thickness of the laminate 10 or the multilayer ceramic capacitor 1 can be measured by, for example, observing a WT cross section near the center in the longitudinal direction of the laminate exposed by polishing, or an LT cross section near the center in the width direction of the laminate or multilayer ceramic capacitor exposed by polishing, using a scanning electron microscope. Each value may also be an average of measurements taken at multiple locations in the longitudinal or width direction. Similarly, the length of the laminate 10 or the length of the multilayer ceramic capacitor 1 can be measured by, for example, observing an LT cross section near the center in the width direction of the laminate or multilayer ceramic capacitor exposed by polishing, using a scanning electron microscope. Each value may also be an average of measurements taken at multiple locations in the thickness direction. Similarly, the width of the laminate 10 or the width of the multilayer ceramic capacitor 1 can be measured by, for example, observing a WT cross section near the center in the longitudinal direction of the laminate or multilayer ceramic capacitor exposed by polishing, using a scanning electron microscope. Each value may also be an average of measurements taken at multiple locations in the thickness direction.

[0032] Each of the two sets of external electrodes 40 includes a first external electrode 41 and a second external electrode 42 .

[0033] The first external electrode 41 is arranged on the second main surface TS2 of the laminate 10, specifically on a part of the second main surface TS2 on the first end face LS1 side, and is connected to the first internal electrode layer 31. The first external electrode 41 is also arranged on the first main surface TS1 of the laminate 10, specifically on a part of the first main surface TS1 on the first end face LS1 side, and is connected to the first internal electrode layer 31. The first external electrode 41 is not arranged on the first end face LS1 or the two side faces WS1, WS2.

[0034] The second external electrode 42 is arranged on the second main surface TS2 of the laminate 10, specifically, on a portion of the second main surface TS2 on the second end face LS2 side, and is connected to the second internal electrode layer 32. The second external electrode 42 is also arranged on the first main surface TS1 of the laminate 10, specifically, on a portion of the first main surface TS1 on the second end face LS2 side, and is connected to the second internal electrode layer 32. The second external electrode 42 is not arranged on the second end face LS2 or the two side faces WS1, WS2.

[0035] In the present embodiment, an example has been given in which two sets of external electrodes 40 are formed on each of the first main surface TS1 and the second main surface TS2 of the laminate 10, but an example in which one set of external electrodes 40 is formed on only one of the first main surface TS1 and the second main surface TS2 of the laminate 10 (mounting surface) is also possible. In this example, the lead electrodes 312 and 322 are not formed on the main surface on which one set of external electrodes 40 is not formed. Note that, since surface-mount electronic components often do not have a distinguishable top surface and a bottom surface, it is preferable that two sets of external electrodes 40 are formed on each of the first main surface TS1 and the second main surface TS2 of the laminate 10.

[0036] Each of the first external electrode 41 and the second external electrode 42 has a base electrode layer and a plating layer. Note that each of the first external electrode 41 and the second external electrode 42 may be composed of only a plating layer.

[0037] The base electrode layer may be a fired layer containing a metal and glass. The glass may include a glass component containing at least one element selected from B, Si, Ba, Mg, Al, Li, and the like. A specific example is borosilicate glass. The metal may include Cu as a main component. The metal may include at least one element selected from metals such as Ni, Ag, Pd, and Au, or alloys such as Ag-Pd alloys, as a main component or as a component other than the main component.

[0038] The fired layer is a layer formed by applying a conductive paste containing metal and glass to the laminate by a dipping method and firing the layer. The fired layer may be fired after firing the internal electrode layer or simultaneously with firing the internal electrode layer. The fired layer may also be a multi-layer structure.

[0039] Alternatively, the base electrode layer may be a resin layer containing conductive particles and a thermosetting resin. The resin layer may be formed on the fired layer described above, or may be formed directly on the laminate without forming a fired layer.

[0040] The resin layer is a layer formed by applying a conductive paste containing conductive particles and a thermosetting resin to the laminate by a coating method and then firing the layer. The resin layer may be fired after firing the internal electrode layer or simultaneously with firing the internal electrode layer. The resin layer may also be a multi-layered layer.

[0041] The thickness of each of the base electrode layers as the fired layer or resin layer is not particularly limited, and may be 1 μm or more and 10 μm or less.

[0042] Alternatively, the base electrode layer may be a thin film layer of 1 μm or less formed by a thin film forming method such as sputtering or vapor deposition, in which metal particles are deposited.

[0043] The plating layer covers at least a portion of the base electrode layer and includes at least one selected from the group consisting of metals such as Cu, Ni, Ag, Pd, and Au, and alloys such as Ag—Pd alloys.

[0044] The plating layer may be formed of multiple layers, preferably a two-layer structure of Ni plating and Sn plating. The Ni plating layer can prevent the base electrode layer from being eroded by solder when mounting the ceramic electronic component, and the Sn plating layer improves the wettability of the solder when mounting the ceramic electronic component, facilitating mounting.

[0045] The thickness of each plating layer is not particularly limited and may be 1 μm or more and 10 μm or less.

[0046] <Manufacturing Method> Next, a method for manufacturing the above-mentioned multilayer ceramic capacitor 1 will be described. First, a dielectric sheet for the dielectric layers 20 and a conductive paste for the internal electrode layers 30 are prepared. The dielectric sheet and the conductive paste contain a binder and a solvent. Known materials can be used as the binder and the solvent.

[0047] Next, a conductive paste is printed on the dielectric sheet in a predetermined pattern, for example, to form an internal electrode pattern on the dielectric sheet. The internal electrode pattern can be formed by screen printing, gravure printing, or the like.

[0048] Next, a predetermined number of dielectric sheets for the second outer layer portion 102, on which no internal electrode pattern is printed, are stacked. On top of these, dielectric sheets for the inner layer portion 100, on which internal electrode patterns are printed, are stacked in sequence. On top of these, a predetermined number of dielectric sheets for the first outer layer portion 101, on which no internal electrode pattern is printed, are stacked. In this way, a laminated sheet is produced.

[0049] Next, the laminated sheet is pressed in the lamination direction using a means such as a hydrostatic press to produce a laminated block. Next, the laminated block is cut to a predetermined size to cut out laminated chips. At this time, the corners and ridges of the laminated chips are rounded by barrel polishing or the like. Next, the laminated chips are fired to produce the laminate 10. The firing temperature depends on the materials of the dielectric and internal electrodes, but is preferably 900°C or higher and 1400°C or lower.

[0050] Next, a conductive paste, which is an electrode material for the base electrode layer, is applied to the second main surface TS2 and the first main surface TS1 of the laminate 10 using a coating method. The conductive paste is then fired to form the base electrode layer, which is a fired layer. The firing temperature is preferably 600° C. or higher and 900° C. or lower.

[0051] The thin film base electrode layer may be formed by a thin film forming method such as sputtering or vapor deposition.

[0052] In the above description, the base electrode layer is formed and fired after firing the laminated chip, i.e., the laminate and the external electrodes are fired separately. However, the base electrode layer may be formed and fired before firing the laminated chip, i.e., the laminate and the external electrodes may be fired simultaneously.

[0053] Thereafter, a plating layer is formed on the surface of the base electrode layer to form the first external electrode 41 and the second external electrode 42. Through the above steps, the multilayer ceramic capacitor 1 described above is obtained.

[0054] <Mounting Structure> Next, a mounting structure in which the above-described multilayer ceramic capacitor 1 is mounted on a circuit board will be described. Fig. 4 is a perspective view showing the mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to this embodiment. As shown in Fig. 4, the mounting structure 90 includes a circuit board CB and the multilayer ceramic capacitor 1.

[0055] The circuit board CB has a first land electrode 51 and a second land electrode 52 that are arranged spaced apart in the longitudinal direction L. As described above, the multilayer ceramic capacitor 1 has, on at least the second main surface TS2 (mounting surface), a first external electrode 41 and a second external electrode 42 that are arranged spaced apart in the longitudinal direction L. The first external electrode 41 of the multilayer ceramic capacitor 1 is connected to the first land electrode 51 of the circuit board CB via solder paste 60, and the second external electrode 42 of the multilayer ceramic capacitor 1 is connected to the second land electrode 52 of the circuit board CB via solder paste 60.

[0056] The outer end of the first external electrode 41 opposite the second external electrode 42 in the longitudinal direction L is located closer to the second external electrode 42 and the second land electrode 52 than the outer end of the first land electrode 51 opposite the second land electrode 52 in the longitudinal direction L. Furthermore, the outer end of the second external electrode 42 opposite the first external electrode 41 in the longitudinal direction L is located closer to the first external electrode 41 and the first land electrode 51 than the outer end of the second land electrode 52 opposite the first land electrode 51 in the longitudinal direction L.

[0057] The inner end of the first external electrode 41 on the second external electrode 42 side in the longitudinal direction L is located closer to the second external electrode 42 and the second land electrode 52 than the inner end of the first land electrode 51 on the second land electrode 52 side in the longitudinal direction L. Furthermore, the inner end of the second external electrode 42 on the first external electrode 41 side in the longitudinal direction L is located closer to the first external electrode 41 and the first land electrode 51 than the inner end of the second land electrode 52 on the first land electrode 51 side in the longitudinal direction L.

[0058] The distance between the inner end of the first external electrode 41 and the inner end of the second external electrode 42 is preferably shorter than the distance between the inner end of the first land electrode 51 and the inner end of the second land electrode 52 .

[0059] The dimension in the length direction L of each of the first external electrode 41 and the second external electrode 42 is preferably 74% or more of the dimension in the length direction L of each of the first land electrode 51 and the second land electrode 52 .

[0060] The dimension of each of the first external electrode 41 and the second external electrode 42 in the width direction W may be 0.12 mm or more and 0.21 mm or less.

[0061] Here, a well-known surface-mount type multilayer ceramic electronic component has external electrodes disposed on its end faces. In such a multilayer ceramic electronic component, fillets of paste solder are formed on the external electrodes on the end faces of the multilayer ceramic electronic component during the mounting process of the multilayer ceramic electronic component on a circuit board, thereby stabilizing the mounting posture of the multilayer ceramic electronic component (mountability).

[0062] However, there is a demand for further miniaturization of such multilayer ceramic electronic components. Furthermore, there is a demand for higher density mounting in the mounting structure of such multilayer ceramic electronic components. From the viewpoint of high density mounting, it is conceivable to reduce the area occupied by the fillets of paste solder formed on the external electrodes on the end faces of the multilayer ceramic electronic component. In this regard, it is conceivable to arrange the external electrodes not on the end faces of the multilayer ceramic electronic component but on the mounting surface of the multilayer ceramic electronic component.

[0063] However, according to the findings of the present inventors, in a multilayer ceramic electronic component that does not have external electrodes disposed on its end faces, a fillet of paste solder is not formed on the end faces of the multilayer ceramic electronic component during the mounting process of the multilayer ceramic electronic component, and therefore the mounting posture of the multilayer ceramic electronic component is unstable, and for example, the component may float and tilt. This decrease in the stability of the mounting posture can become more pronounced as the multilayer ceramic electronic component becomes smaller.

[0064] The following findings have been obtained from the experimental results of the present inventors: Figures 5 and 6 are side views showing the mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to this embodiment, and Figures 7 and 8 are side views showing the mounting structure of the multilayer ceramic capacitor (multilayer ceramic electronic component) according to a comparative example.

[0065] The mounting structure 90 of the embodiment shown in Fig. 6 differs from the mounting structure 90 of the embodiment shown in Fig. 5 mainly in the following points: the distance between the inner end of the first external electrode 41 and the inner end of the second external electrode 42 is short, the inner end of the first external electrode 41 is located further toward the second external electrode 42 and the second land electrode 52 than the inner end of the first land electrode 51, and the inner end of the second external electrode 42 is located further toward the first external electrode 41 and the first land electrode 51 than the inner end of the second land electrode 52.

[0066] The mounting structure 90X of the comparative example shown in Fig. 7 differs from the mounting structure 90 of the embodiment shown in Fig. 5 mainly in the following respects: The first external electrode 41X and the second external electrode 42X of the multilayer ceramic capacitor 1X are each small in size, in other words, the dimension in the length direction L of each of the first external electrode 41X and the second external electrode 42X is less than 74% of the dimension in the length direction L of each of the first land electrode 51 and the second land electrode 52, The inner end of the first external electrode 41X of the multilayer ceramic capacitor 1X is located at approximately the same position in the length direction L as the inner end of the first land electrode 51, and The inner end of the second external electrode 42X of the multilayer ceramic capacitor 1X is located at approximately the same position in the length direction L as the inner end of the second land electrode 52.

[0067] The mounting structure 90X of the comparative example shown in FIG. 8 differs from the mounting structure 90 of the embodiment shown in FIG. 5 mainly in the following respects. the size of each of the first external electrode 41X and the second external electrode 42X of the multilayer ceramic capacitor 1X is small; in other words, the dimension in the length direction L of each of the first external electrode 41X and the second external electrode 42X is less than 74% of the dimension in the length direction L of each of the first land electrode 51 and the second land electrode 52; the distance between the inner end of the first external electrode 41X and the inner end of the second external electrode 42X of the multilayer ceramic capacitor 1X is long; the inner end of the first external electrode 41X of the multilayer ceramic capacitor 1X is located on the opposite side to the second external electrode 42X and the second land electrode 52 than the inner end of the first land electrode 51; and the inner end of the second external electrode 42X of the multilayer ceramic capacitor 1X is located on the opposite side to the first external electrode 41X and the first land electrode 51 than the inner end of the second land electrode 52.

[0068] As shown in Figures 5 to 8, if the outer end of the first external electrode 41 (41X) is located closer to the second external electrode 42 (42X) and the second land electrode 52 than the outer end of the first land electrode 51, and the outer end of the second external electrode 42 (42X) is located closer to the first external electrode 41 (41X) and the first land electrode 51 than the outer end of the second land electrode 52, then it is believed that in the mounting process of the multilayer ceramic capacitor 1 (1X), the force acting from the paste solder 60 on the outer ends of the external electrodes 41, 42 (41X, 42X) is directed inward in the longitudinal direction L (see arrows in Figures 5 to 8).

[0069] 8 , if the inner end of the first external electrode 41X is located on the opposite side of the second external electrode 42X and the second land electrode 52 from the inner end of the first land electrode 51, and the inner end of the second external electrode 42X is located on the opposite side of the first external electrode 41X and the first land electrode 51 from the inner end of the second land electrode 52, then it is considered that, in the mounting process of the multilayer ceramic capacitor 1X, the force acting from the paste solder 60 on the inner ends of the external electrodes 41X, 42X is directed outward in the longitudinal direction L (see the arrows in FIG. 8 ). In this way, if the force acting on the outer ends of the external electrodes 41X, 42X and the force acting on the inner ends of the external electrodes 41X, 42X are directed in the longitudinal direction L opposite to each other, the multilayer ceramic capacitor 1X will float and tilt.

[0070] 7 , if the inner end of the first external electrode 41X is located at approximately the same position in the longitudinal direction L as the inner end of the first land electrode 51, and the inner end of the second external electrode 42X is located at approximately the same position in the longitudinal direction L as the inner end of the second land electrode 52, then it is considered that, in the mounting process of the multilayer ceramic capacitor 1X, the force acting from the paste solder 60 to the inner ends of the external electrodes 41X, 42X is directed upward (see the arrows in FIG. 7 ). In this way, if the direction of the force acting on the outer ends of the external electrodes 41X, 42X and the direction of the force acting on the inner ends of the external electrodes 41X, 42X differ in the longitudinal direction L, it is considered that the multilayer ceramic capacitor 1X will float and tilt.

[0071] 5 and 8 , if the inner end of the first external electrode 41 is located closer to the second external electrode 42 and the second land electrode 52 than the inner end of the first land electrode 51, and the inner end of the second external electrode 42 is located closer to the first external electrode 41 and the first land electrode 51 than the inner end of the second land electrode 52, then it is believed that the force acting from the solder paste 60 on the inner ends of the external electrodes 41, 42 in the mounting process of the multilayer ceramic capacitor 1 is directed inward in the longitudinal direction L (see the arrows in FIGS. 5 and 6 ). In this way, if the force acting on the outer ends of the external electrodes 41, 42 and the force acting on the inner ends of the external electrodes 41, 42 are in the same direction in the longitudinal direction L, it is believed that it is possible to prevent the multilayer ceramic capacitor 1 from floating and tilting.

[0072] As described above, according to the mounting structure 90 of the multilayer ceramic capacitor (multilayer ceramic electronic component) 1 of this embodiment, the following advantages are achieved: the inner end of the first external electrode 41 on the second external electrode 42 side in the length direction L is located closer to the second external electrode 42 and the second land electrode 52 than the inner end of the first land electrode 51 on the second land electrode 52 side in the length direction L, and the inner end of the second external electrode 42 on the first external electrode 41 side in the length direction L is located closer to the first external electrode 41 and the first land electrode 51 than the inner end of the second land electrode 52 on the first land electrode 51 side in the length direction L. Therefore, during the mounting process of the multilayer ceramic capacitor 1, it is possible to prevent the multilayer ceramic capacitor 1 from floating and tilting, and to prevent a decrease in the stability of the mounted posture of the multilayer ceramic capacitor 1.

[0073] Furthermore, according to the mounting structure 90 of the multilayer ceramic capacitor (multilayer ceramic electronic component) 1 of this embodiment, it is preferable that the distance between the inner end of the first external electrode 41 and the inner end of the second external electrode 42 is shorter than the distance between the inner end of the first land electrode 51 and the inner end of the second land electrode 52. This makes it easy to achieve the positional relationship between the inner end of the first external electrode 41 and the inner end of the first land electrode 51, and the positional relationship between the inner end of the second external electrode 42 and the inner end of the second land electrode 52.

[0074] Furthermore, according to the mounting structure 90 of the multilayer ceramic capacitor (multilayer ceramic electronic component) 1 of this embodiment, the dimension in the length direction L of each of the first external electrodes 41 and the second external electrodes 42 is preferably 74% or more of the dimension in the length direction L of each of the first land electrodes 51 and the second land electrodes 52. This increases the contact area between the external electrodes and the paste solder, and further prevents the multilayer ceramic capacitor 1 from floating and tilting during the mounting process of the multilayer ceramic capacitor 1, thereby further preventing a decrease in the stability of the mounting posture of the multilayer ceramic capacitor 1.

[0075] Furthermore, according to the mounting structure 90 of the multilayer ceramic capacitor (multilayer ceramic electronic component) 1 of this embodiment, the dimension in the width direction W of each of the first external electrode 41 and the second external electrode 42 may be 0.12 mm or more and 0.21 mm or less. In this way, the above-mentioned effects are particularly achieved in a miniaturized multilayer ceramic capacitor 1.

[0076] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and various modifications and variations are possible. For example, in the above-described embodiments, a multilayer ceramic capacitor using a dielectric ceramic is exemplified as a multilayer ceramic electronic component. However, the characteristics of the external electrodes of the present invention are not limited to this and can be applied to various multilayer ceramic electronic components such as piezoelectric components using piezoelectric ceramic, thermistors using semiconductor ceramic, and inductors using magnetic ceramic. Examples of piezoelectric ceramics include PZT-based ceramics, examples of semiconductor ceramics include spinel-based ceramics, and examples of magnetic ceramics include ferrite.

[0077] The present invention may also be in the following forms: <1> A mounting structure for a multilayer ceramic electronic component in which a multilayer ceramic electronic component is mounted on a circuit board, the multilayer ceramic electronic component comprising: a laminate in which a plurality of dielectric layers and internal conductor layers made of ceramic material are stacked, the laminate having two main surfaces opposing each other in a thickness direction, two side surfaces opposing each other in a width direction intersecting the thickness direction, and two end faces opposing each other in a length direction intersecting the thickness direction and the width direction; and a first external electrode and a second external electrode arranged on only the two main surfaces of the laminate or on only one of the two main surfaces of the laminate, and spaced apart in the length direction; and the circuit board comprising a first land electrode and a second land electrode arranged on the length direction, and connected to the first external electrode and the second external electrode of the multilayer ceramic electronic component, respectively, and a mounting structure for a multilayer ceramic electronic component, wherein an inner end of the first external electrode on the second external electrode side in the length direction is located closer to the second external electrode and the second land electrode than an inner end of the first land electrode on the second land electrode side in the length direction, and an inner end of the second external electrode on the first external electrode side in the length direction is located closer to the first external electrode and the first land electrode than an inner end of the second land electrode on the first land electrode side in the length direction.

[0078] <2> The mounting structure of a multilayer ceramic electronic component according to <1>, wherein an outer end of the first external electrode opposite to the inner end in the length direction is located closer to the second external electrode and the second land electrode than an outer end of the first land electrode opposite to the inner end in the length direction, and an outer end of the second external electrode opposite to the inner end in the length direction is located closer to the first external electrode and the first land electrode than an outer end of the second land electrode opposite to the inner end in the length direction.

[0079] <3> The mounting structure of a multilayer ceramic electronic component according to <1> or <2>, wherein a distance between the inner end of the first external electrode and the inner end of the second external electrode is shorter than a distance between the inner end of the first land electrode and the inner end of the second land electrode.

[0080] <4> The mounting structure of a multilayer ceramic electronic component according to any one of <1> to <3>, wherein the dimension in the length direction of each of the first external electrode and the second external electrode is 74% or more of the dimension in the length direction of each of the first land electrode and the second land electrode.

[0081] <5> The mounting structure of a multilayer ceramic electronic component according to any one of <1> to <4>, wherein the dimension of each of the first external electrode and the second external electrode in the width direction is 0.12 mm or more and 0.21 mm or less.

[0082] REFERENCE SIGNS LIST 1 Multilayer ceramic capacitor (multilayer ceramic electronic component) 10 Laminate 20 Dielectric layer 30 Internal electrode layer (internal conductor layer) 31 First internal electrode layer 311 Counter electrode portion 312 Lead electrode portion 32 Second internal electrode layer 321 Counter electrode portion 322 Lead electrode portion 40 External electrode 41 First external electrode 42 Second external electrode 51 First land electrode 52 Second land electrode 60 Paste solder 90 Mounting structure 100 Internal layer portion 101 First external layer portion 102 Second external layer portion L Length direction T Thickness direction W Width direction LS1 First end face LS2 Second end face TS1 First main surface TS2 Second main surface WS1 First side surface WS2 Second side surface CB Circuit board

Claims

1. A mounting structure for a multilayer ceramic electronic component in which a multilayer ceramic electronic component is mounted on a circuit board, The multilayer ceramic electronic component comprises: a laminate in which a plurality of dielectric layers and internal conductor layers made of a ceramic material are laminated, the laminate having two main faces opposing each other in a thickness direction, two side faces opposing each other in a width direction intersecting the thickness direction, and two end faces opposing each other in a length direction intersecting the thickness direction and the width direction; a first external electrode and a second external electrode arranged on only the two main surfaces of the laminate or on only one of the two main surfaces of the laminate, the first external electrode and the second external electrode being spaced apart in the longitudinal direction; Equipped with the circuit board includes a first land electrode and a second land electrode that are spaced apart from each other in the longitudinal direction and that are connected to the first external electrode and the second external electrode of the multilayer ceramic electronic component, respectively; an inner end of the first external electrode on the second external electrode side in the longitudinal direction is located closer to the second external electrode and the second land electrode than an inner end of the first land electrode on the second land electrode side in the longitudinal direction, an inner end of the second external electrode on the first external electrode side in the longitudinal direction is located closer to the first external electrode and the first land electrode than an inner end of the second land electrode on the first land electrode side in the longitudinal direction; Mounting structure for multilayer ceramic electronic components.

2. an outer end of the first external electrode opposite to the inner end in the length direction is located closer to the second external electrode and the second land electrode than an outer end of the first land electrode opposite to the inner end in the length direction, an outer end of the second external electrode opposite to the inner end in the length direction is located closer to the first external electrode and the first land electrode than an outer end of the second land electrode opposite to the inner end in the length direction; 2. The mounting structure of a multilayer ceramic electronic component according to claim 1.

3. 3. The mounting structure of a multilayer ceramic electronic component according to claim 1, wherein a distance between the inner end of the first external electrode and the inner end of the second external electrode is shorter than a distance between the inner end of the first land electrode and the inner end of the second land electrode.

4. 3. The mounting structure of a multilayer ceramic electronic component according to claim 1, wherein a dimension in the longitudinal direction of each of the first external electrode and the second external electrode is 74% or more of a dimension in the longitudinal direction of each of the first land electrode and the second land electrode.

5. 3. The mounting structure for a multilayer ceramic electronic component according to claim 1, wherein the dimension in the width direction of each of the first external electrode and the second external electrode is not less than 0.12 mm and not more than 0.21 mm.