Electronic components and mounting structures for electronic components

Abstract

Provided is an electronic component and an electronic component mounting structure that can suppress cracking.　This electronic component comprises a component body 10 having a length direction L, and a first external electrode 21 and a second external electrode 22 that are a pair of external electrodes 20 disposed on respective ends in the length direction L of the component body 10. The component body 10 includes, in at least a part thereof that is exposed between the pair of external electrodes 20, a central periphery portion 30 that is a protruding portion protruding outside the pair of external electrodes 20 in one direction orthogonal to the length direction L.

Description

Technical Field

[0001] The present invention relates to electronic components and a mounting structure for electronic components.

Background Art

[0002] Conventionally, as an electronic component having a two-terminal structure, a multilayer ceramic capacitor in which external electrodes are disposed at both ends of a rectangular parallelepiped body in which a plurality of dielectric layers and a plurality of internal electrode layers are alternately laminated is known. The multilayer ceramic capacitor is mounted by connecting the external electrodes to a pair of lands provided on a substrate by soldering (see Patent Document 1, etc.). Generally, as shown in Patent Document 1, the external electrodes of the multilayer ceramic capacitor protrude downward from the substrate side of the main body. Therefore, the external electrodes contact the lands, and a space is formed between the surface of the substrate and the main body.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] When mounting a conventional multilayer ceramic capacitor on a substrate as described above, it is difficult for solder to penetrate between the land and the external electrode, and it is difficult to make the amount of solder between the land and the external electrode sufficient. If the amount of solder in this part is not sufficient, when the substrate deflects, stress tends to concentrate on the edge of the portion extending to the main body side of the external electrode, and cracks may occur in the main body starting from this part. Therefore, there is room for improvement.

[0005] Therefore, an object of the present invention is to provide an electronic component and a mounting structure for an electronic component that can suppress the occurrence of cracks.

Means for Solving the Problems

[0006] The electronic component of the present invention comprises a component body having a longitudinal direction, and a pair of external electrodes arranged at both ends of the component body in the longitudinal direction, wherein the component body has a projection in at least a portion of the portion exposed between the pair of external electrodes that protrudes outward from the pair of external electrodes in a direction perpendicular to the longitudinal direction.

[0007] The present invention provides an electronic component mounting structure in which each of a pair of external electrodes of an electronic component is connected to a pair of lands arranged spaced apart from each other on the surface of a substrate, wherein the electronic component comprises a component body and the pair of external electrodes arranged on the component body, the component body is in contact with the substrate, and a gap exists between each of the pair of external electrodes and the substrate. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide electronic components and mounting structures for electronic components that can suppress the occurrence of cracks. [Brief explanation of the drawing]

[0009] [Figure 1] This is a schematic perspective view of a multilayer ceramic capacitor according to an embodiment. [Figure 2] This is a view from the direction of arrow II in Figure 1. [Figure 3] This is a view from the direction of arrow III in Figure 1. [Figure 4] This is a cross-sectional view taken along line IV-IV in Figure 2. [Figure 5] Figure 3 is a cross-sectional view of the VV section. [Figure 6] This diagram schematically shows an example of a method for manufacturing a multilayer ceramic capacitor according to an embodiment, with the steps shown in the order of (a) to (d). [Figure 7] This is a plan view showing the implementation structure according to the embodiment. [Figure 8] This is a cross-sectional view taken along line VIII-VIII in Figure 7. [Figure 9]This is an enlarged view of section IX in Figure 8. [Figure 10] This diagram shows a conventional implementation structure and corresponds to Figure 9. [Figure 11] This is a cross-sectional view of a modified example of the multilayer ceramic capacitor of the embodiment, and corresponds to Figure 5. [Modes for carrying out the invention]

[0010] The embodiments will now be described with reference to the drawings. Figure 1 is a schematic perspective view of a multilayer ceramic capacitor 1 as an electronic component according to the embodiment. Figure 2 is a view taken in the direction of arrow II in Figure 1. Figure 3 is a view taken in the direction of arrow III in Figure 1. Figure 4 is a cross-sectional view taken along line IV-IV in Figure 2. Figure 5 is a cross-sectional view taken along line VV in Figure 3.

[0011] As shown in Figure 1, the multilayer ceramic capacitor 1 of this embodiment has a substantially rectangular parallelepiped shape overall. This multilayer ceramic capacitor 1 comprises a component body 10 and a pair of external electrodes 20 arranged on the component body 10 spaced apart from each other.

[0012] As shown in Figures 2 and 3, the component body 10 has a base portion 11 and a central outer peripheral portion 30 provided on the base portion 11.

[0013] In FIGS. 1 to 3, arrow L indicates the length direction of the multilayer ceramic capacitor 1 and the body part 11. In FIGS. 1 and 2, arrow W indicates the width direction of the multilayer ceramic capacitor 1 and the body part 11, which is orthogonal to the length direction. In FIGS. 1 and 3, arrow T indicates the lamination direction of the multilayer ceramic capacitor 1 and the body part 11, which is orthogonal to the length direction L and the width direction W. The lamination direction T corresponds to the thickness direction of the multilayer ceramic capacitor 1 and the body part 11. The cross-sectional view shown in FIG. 4 shows the LT cross-section, which is a cross-section along the length direction L and the lamination direction T at the center in the width direction W of the multilayer ceramic capacitor 1. The cross-sectional view shown in FIG. 5 shows the WT cross-section, which is a cross-section along the width direction W and the lamination direction T at the center in the length direction L of the multilayer ceramic capacitor 1.

[0014] Examples of the dimensions of the multilayer ceramic capacitor 1 include, but are not limited to, a length direction L of 0.2 mm or more and 1.2 mm or less, a width direction W of 0.1 mm or more and 0.7 mm or less, and a lamination direction T of 0.1 mm or more and 0.7 mm or less.

[0015] As shown in FIGS. 1 to 3, the pair of external electrodes 20 includes a first external electrode 21 disposed at one end in the length direction L of the body part 11 and a second external electrode 22 disposed at the other end in the length direction L of the body part 11. Hereinafter, when the first external electrode 21 and the second external electrode 22 having the same configuration are described without distinction, both may be simply referred to as the external electrode 20.

[0016] As shown in FIG. 4, both the first external electrode 21 and the second external electrode 22 are each composed of a laminated film of a sintered metal layer 20a and a plating layer 20b. The sintered metal layer 20a is formed by baking a paste of, for example, Cu, Ni, Ag, Pd, an Ag-Pd alloy, Au, or the like. The plating layer 20b is composed of, for example, a Ni plating layer and a Sn plating layer covering the Ni plating layer. The plating layer 20b may be a Cu plating layer or an Au plating layer instead. Note that the external electrode 20 may be composed only of a plating layer or may be formed using a conductive resin paste.

[0017] As shown in FIGS. 2 and 5, the base body portion 11 includes a laminate 12 and a pair of side dielectric ceramic layers 15 that cover the side surfaces on both sides in the width direction of the laminate 12.

[0018] The laminate 12 includes a plurality of dielectric ceramic layers 13 laminated alternately in the lamination direction T and an internal electrode layer 14 as an internal electrode. The laminate 12 has a lamination direction T, a length direction L, and a width direction W that are the same as those of the multilayer ceramic capacitor 1 and the base body portion 11.

[0019] The dielectric ceramic layer 13 and the side dielectric ceramic layer 15 are formed by firing a ceramic material mainly composed of, for example, barium titanate. The dielectric ceramic layer 13 and the side dielectric ceramic layer 15 may be formed of other high-permittivity ceramic materials (for example, those mainly composed of CaTiO3, SrTiO3, CaZrO3, etc.). The ceramic material forming the dielectric ceramic layer 13 and the side dielectric ceramic layer 15 contains additives such as Si, Mg, Mn, Sn, Cu, rare earths, Ni, and Al for the purpose of adjusting the composition, for example. The dielectric ceramic layer 13 and the side dielectric ceramic layer 15 may be formed of the same material or different materials from among the ceramic materials as described above.

[0020] The internal electrode layer 14 is formed of a metal material typified by, for example, Ni, Cu, Ag, Pd, an Ag-Pd alloy, Au, etc. The internal electrode layer 14 is not limited to these metal materials and may be formed of other conductive materials.

[0021] As shown in FIG. 4, of a pair of internal electrode layers 14 adjacent to each other with one dielectric ceramic layer 13 interposed therebetween in the lamination direction T, one is electrically connected to the first external electrode 21, and the other is electrically connected to the second external electrode 22. Thereby, between the first external electrode 21 and the second external electrode 22, a structure is formed in which a plurality of capacitor elements are electrically connected in parallel.

[0022] As shown in Figures 4 and 5, the dielectric ceramic layer 13 comprises a plurality of first dielectric ceramic layers 13a sandwiched between the internal electrode layers 14, and a pair of second dielectric ceramic layers 13b arranged at both ends in the stacking direction T, with a thickness greater than that of the first dielectric ceramic layers 13a.

[0023] As shown in Figures 4 and 5, the laminate 12 has an inner layer portion 12A in which each of the multiple internal electrode layers 14 faces the other via a first dielectric ceramic layer 13a, and a pair of outer layer portions 12B arranged to sandwich the inner layer portion 12A in the stacking direction. That is, in the inner layer portion 12A, the multiple internal electrode layers 14 are stacked alternately via the first dielectric ceramic layer 13a.

[0024] As shown in Figures 3 to 5, the laminate 12 has a first main surface 17a1 and a second main surface 17a2 that are opposite each other in the stacking direction T. As shown in Figures 2 and 5, the laminate 12 has a first side surface 17b1 and a second side surface 17b2 that are opposite each other in the width direction W. As shown in Figures 2 to 4, the laminate 12 has a first end surface 17c1 and a second end surface 17c2 that are opposite each other in the length direction L. A first external electrode 21 is placed on the first end surface 17c1, and a second external electrode 22 is placed on the second end surface 17c2.

[0025] As shown in Figures 2 and 5, side dielectric ceramic layers 15 are arranged on the first side surface 17b1 and the second side surface 17b2 of the laminate 12, respectively. These pair of side dielectric ceramic layers 15 include a first side dielectric ceramic layer 15A that covers the first side surface 17b1 and a second side dielectric ceramic layer 15B that covers the second side surface 17b2. In the following description, when the first side dielectric ceramic layer 15A and the second side dielectric ceramic layer 15B, which have the same configuration, are not distinguished, they may both be simply referred to as side dielectric ceramic layers 15.

[0026] The first side dielectric ceramic layer 15A has a third surface 15a that constitutes one side of the base body 11. The second side dielectric ceramic layer 15B has a fourth surface 15b that constitutes the other side of the base body 11. The third surface 15a and the fourth surface 15b face each other in a pair in the width direction W. The pair of surfaces of the base body 11 that face each other in the stacking direction T are none other than the first main surface 17a1 and the second main surface 17a2 of the laminate 12. Therefore, in the following, the first main surface 17a1 and the second main surface 17a2 of the laminate 12 may be referred to as the first main surface 17a1 and the second main surface 17a2 of the base body 11.

[0027] As described above, a first external electrode 21 is positioned on the first end face 17c1, and a second external electrode 22 is positioned on the second end face 17c2. The first external electrode 21 covers the entire surface of the first end face 17c1 and is formed to span four surfaces: the first main surface 17a1 and the second main surface 17a2, and the first side surface 17b1 and the second side surface 17b2, which are opposite to each other.

[0028] As shown in Figures 2 to 4, the first external electrode 21 has an end face portion 21a that covers the entire surface of the first end face 17c1, and a rectangular tubular bent portion 21b that bends inward in the longitudinal direction L from the periphery of the end face portion 21a and covers parts of the first main surface 17a1 and the second main surface 17a2, and the third side surface 15a and the fourth side surface 15b of the base body portion 11. Similarly, the second external electrode 22 has an end face portion 22a that covers the entire surface of the second end face 17c2, and a rectangular tubular bent portion 22b that bends inward in the longitudinal direction L from the periphery of the end face portion 22a and covers parts of the first main surface 17a1 and the second main surface 17a2, and the third side surface 15a and the fourth side surface 15b of the base body portion 11.

[0029] The central outer periphery 30 is the portion exposed between the pair of external electrodes 20. In this embodiment, the central outer periphery 30 covers the outer circumferential surface of the base body 11 between the pair of external electrodes 20, i.e., the first main surface 17a1 and the second main surface 17a2, the third side surface 15a and the fourth side surface 15b, a total of four surfaces. In other words, the central outer periphery 30 is provided around the entire outer periphery of the component body 10.

[0030] The thickness of the central outer peripheral portion 30 covering the first main surface 17a1 and the second main surface 17a2, the third side surface 15a and the fourth side surface 15b of the base body portion 11, that is, the distance from the surfaces of the first main surface 17a1 and the second main surface 17a2, the third side surface 15a and the fourth side surface 15b to the surface of the central outer peripheral portion 30, is greater than the film thickness of the bent portions 21b and 22b of the external electrode 20. Therefore, the central outer peripheral portion 30 protrudes outward in the lamination direction T and outward in the width direction W than the bent portions 21b and 22b.

[0031] The central outer periphery 30 includes a first projection 31 covering the first main surface 17a1, a second projection 32 covering the second main surface 17a2, a third projection 33 covering the third side surface 15a, and a fourth projection 34 covering the fourth side surface 15b, between the pair of external electrodes 20. The first projection 31 and the second projection 32 protrude outward in the stacking direction T, which is perpendicular to the length direction L, from the surfaces of the bent portions 21b and 22b of the external electrodes 20. The third projection 33 and the fourth projection 34 protrude outward in the width direction W, which is perpendicular to the length direction L, from the surfaces of the bent portions 21b and 22b of the external electrodes 20. The stacking direction T and the width direction W are each one direction perpendicular to the length direction. The central outer peripheral portion 30, which has a first protrusion 31, a second protrusion 32, a third protrusion 33, and a fourth protrusion 34, is an example of a protrusion that protrudes outward from the external electrode 20 in one direction perpendicular to the longitudinal direction L.

[0032] As shown in Figure 3, the first protrusion 31 and the second protrusion 32 protrude outward in the stacking direction T by a dimension H from the respective surfaces of the bent portion 21b of the first external electrode 21 and the bent portion 22b of the second external electrode 22. As shown in Figure 2, the third protrusion 33 and the fourth protrusion 34 protrude outward in the width direction W from the respective surfaces of the bent portion 21b of the first external electrode 21 and the bent portion 22b of the second external electrode 22 by a dimension H. Here, each dimension H is preferably 15 μm or more.

[0033] The surface of the first projection 31 is flat and substantially parallel to the first main surface 17a1. The surface of the second projection 32 is flat and substantially parallel to the second main surface 17a2. The surface of the third projection 33 is flat and substantially parallel to the third side surface 15a. The surface of the fourth projection 34 is flat and substantially parallel to the fourth side surface 15b.

[0034] The central outer periphery 30 can be formed on the surface of the base body 11 from at least one material, such as ceramic and resin. If the central outer periphery 30 is made of ceramic, it may be the same ceramic material as the dielectric ceramic layer 13 or the side dielectric ceramic layer 15. If the central outer periphery 30 is made of resin, a synthetic resin such as epoxy resin or acrylic resin can be used.

[0035] Here, with reference to Figure 6, an example of a method for manufacturing the multilayer ceramic capacitor 1 of the embodiment will be briefly described. Figure 6 schematically shows the steps related to the manufacturing of the multilayer ceramic capacitor 1 in the order of (a) to (d). In this case, the central outer circumference 30 is formed of ceramic.

[0036] First, as shown in Figure 6(a), the base body 11 is manufactured. The base body 11 is manufactured by laminating a ceramic material such as a ceramic green sheet which will become the dielectric ceramic layer 13 and a conductive material such as a conductive paste which will become the internal electrode layer 14 to form a laminate 12. Then, a ceramic material such as a ceramic green sheet which will become the side dielectric ceramic layer 15 is attached to the first side surface 17b1 and the second side surface 17b2 of the laminate 12. Next, as shown in Figure 6(b), a ceramic material such as a ceramic green sheet which will become the central outer circumference 30 is attached to the base body 11. This manufactures the component body 10 before firing. Next, this component body 10 is fired to manufacture the fired component body 10 shown in Figure 6(c). Then, as shown in Figure 6(d), external electrodes 20 are formed at both ends of the base body 11 in the longitudinal direction L. When the central outer periphery 30 is formed from the same ceramic material as the laminate 12 and the side dielectric ceramic layer 15, the central outer periphery 30 becomes integrated with the base body 11.

[0037] If the central outer periphery 30 is formed of the above-mentioned resin, the central outer periphery 30 can be formed after the external electrodes 20 have been formed by, for example, injecting and applying a liquid resin material to the outer surface of the base body portion 11 between the external electrodes 20 using an appropriate jig, and then curing the applied resin material.

[0038] Next, the mounting structure of the multilayer ceramic capacitor 1 according to the embodiment will be described. Figure 7 is a plan view showing the mounting structure according to the embodiment. Figure 8 is a cross-sectional view taken along line VIII-VIII in Figure 7. In the mounting structure according to the embodiment, the multilayer ceramic capacitor 1 is mounted on a substrate 50.

[0039] As shown in Figures 7 and 8, the mounting structure according to the embodiment is such that each of the pair of external electrodes 20 of the multilayer ceramic capacitor 1 is connected to a first land 61 and a second land 62, which are lands arranged spaced apart from each other on the surface of the substrate 50.

[0040] The substrate 50 is formed in sheet form from an insulating material such as resin, glass, glass epoxy, paper phenol, or ceramics. The areas of the substrate 50 surface that require insulation are covered with a resist film. The multilayer ceramic capacitor 1 is mounted on the substrate 50 with its length direction L approximately parallel to the X direction shown in Figures 7 and 8, and its width direction W approximately parallel to the Y direction which is perpendicular to the X direction. In Figure 7, both the X and Y directions are plane directions along the surface of the substrate 50. Note that Figure 7 also shows the length direction L and width direction W of the multilayer ceramic capacitor 1. Figure 8 also shows the length direction L and stacking direction T of the multilayer ceramic capacitor 1. In Figure 8, Z indicates the vertical direction perpendicular to the X and Y directions.

[0041] The substrate 50 may be made of glass or paper fibers. The fibers constituting the substrate may have a fiber direction that extends in one direction. When the substrate 50 has a fiber direction that extends in one direction, in the embodiment, it is preferable that the mounting position of the multilayer ceramic capacitor 1 be set such that the fiber direction extends in the X direction in Figures 7 and 8. That is, it is preferable that the direction in which the pair of external electrodes 20 of the multilayer ceramic capacitor 1 are spaced apart from each other is parallel to the fiber direction of the substrate 50. Arranged in parallel means that the two directions are arranged so that they form an angle of -5° or more and less than +5°.

[0042] The first land 61 and the second land 62 are spaced apart from each other in the X direction. Both the first land 61 and the second land 62 have a rectangular shape in plan view and the same dimensions. A separation portion 51 covered with a resist film is provided between the first land 61 and the second land 62. The first land 61 and the second land 62 are arranged in parallel, spaced apart in the X direction, with the separation portion 51 in between, so that their positions in the Y direction are the same.

[0043] In the multilayer ceramic capacitor 1, the bent portion 21b of the first external electrode 21 is connected to the first land 61, and the bent portion 22b of the second external electrode 22 is connected to the second land 62. In the embodiment, as shown in Figure 8, the first connecting bent portion 21b1 of the first bent portion 21b, which covers the second main surface 17a2 of the base portion 11, is connected to the first land 61, and the second connecting bent portion 22b1 of the second bent portion 22b, which covers the second main surface 17a2 of the base portion 11, is connected to the second land 62. Note that the connection portions of the first external electrode 21 and the second external electrode 22 to the substrate 50 may be the portions of the bent portion 21b and the bent portion 22b that cover the first main surface 17a1. Furthermore, the connection portions of the first external electrode 21 and the second external electrode 22 to the substrate 50 may be the portions of the bent portions 21b and 22b that cover the first side surface 17b1, or they may be the portions that cover the second side surface 17b2.

[0044] The first land 61 and the second land 62 are connected to wiring (not shown) formed on the substrate 50. The first land 61 and the second land 62 are provided at the ends of the wiring, respectively. That is, the wiring is discontinuous with the separation portion 51 in between, and electrical conductivity is established when the multilayer ceramic capacitor 1 is connected to the first land 61 and the second land 62.

[0045] The first land 61, the second land 62, and the above wiring are preferably formed of a highly conductive metal, for example, by depositing Cu on the surface of the substrate 50. The highly conductive metal may also be Ag or Au.

[0046] In the mounting structure of the embodiment, as shown in Figure 8, the second protrusion 32 of the central outer peripheral portion 30 of the multilayer ceramic capacitor 1 is set and in contact with the surface of the separated portion 51 of the substrate 50. The second protrusion 32 is the portion that covers the second main surface 17a2 of the base portion 11. The surface of the second protrusion 32 that contacts the surface of the substrate 50 is flat and substantially parallel to the second main surface 17a2. Therefore, the multilayer ceramic capacitor 1 can be set on the substrate 50 in a stable position. The first connection bend portion 21b1 of the first external electrode 21 faces the first land 61 of the substrate 50, and the second connection bend portion 22b1 of the second external electrode 22 faces the second land 62 of the substrate 50.

[0047] The second protrusion 32 protrudes downward (outside the stacking direction T of the multilayer ceramic capacitor 1) in Figure 8 compared to the first and second connecting bends 21b1 and 22b1 on both sides in the longitudinal direction L. Therefore, in a multilayer ceramic capacitor 1 with the second protrusion 32 set in the separated portion 51, there are gaps G between the first connecting bend 21b1 and the first land 61, and between the second connecting bend 22b1 and the second land 62. That is, the first external electrode 21 and the second external electrode 22 are floating above the surface of the substrate 50. The gap G is equal to the dimension H of the protrusion amount from the first bend 21b and the second bend 22b at the central outer peripheral portion 30 shown in Figure 3. That is, it is preferable that the gap G is 15 μm or more.

[0048] In the configuration described above, the multilayer ceramic capacitor 1 is mounted on the substrate 50. Mounting to the substrate 50 involves soldering the first external electrode 21 to the first land 61 and the second external electrode 22 to the second land 62. As shown in Figures 7 and 8, the first external electrode 21 and the first land 61, and the second external electrode 22 and the second land 62 are electrically connected via solder 70.

[0049] Figure 9 is an enlarged view of the portion indicated by IX in Figure 8. As shown in Figure 9, the solder 70 fills the gap G between the first connection bend portion 21b1 of the first external electrode 21 and the first land 61, and is provided from this gap G to the end face portion 21a of the first external electrode 21.

[0050] Here, Figure 10 shows a conventional multilayer ceramic capacitor mounted on a substrate 50, and shows the part corresponding to Figure 9. In Figure 10, the same reference numerals are used for components corresponding to the embodiment. As shown in Figure 10, in a conventional multilayer ceramic capacitor, the first external electrode 21 protrudes downward from the base part 11 of the component body 10, so the first external electrode 21 contacts the first land 61. Therefore, when the multilayer ceramic capacitor is set on the substrate 50, there is no gap G between the first external electrode 21 and the first land 61, as in the embodiment. For this reason, when soldering, the solder 70 does not easily penetrate between the first external electrode 21 and the first land 61, and it is difficult to make the amount of solder 70 between the first external electrode 21 and the first land 61 sufficient. If the amount of solder 70 in this area is insufficient, stress will be applied to the substrate 50 in a way that causes it to bend along the length L of the multilayer ceramic capacitor. When the substrate 50 bends, stress tends to concentrate at the edge 23b of the bent portion 21b, and there is a risk that a crack K may form in the base portion 11 starting from this edge 23b.

[0051] In contrast, according to the multilayer ceramic capacitor 1 and mounting structure of the embodiment, a gap G exists between the first external electrode 21 and the first land 61, so that a sufficient amount of solder 70 can be filled between the first external electrode 21 and the first land 61 when soldered. If the gap G is 15 μm or more, the amount of solder 70 between the first external electrode 21 and the first land 61 can be made sufficient. Therefore, when the substrate 50 bends as described above, stress is less likely to concentrate at the edge 23b of the bent portion 21b, and the occurrence of cracks in the base portion 11 starting from this edge 23b is suppressed.

[0052] Although Figure 9 shows the first external electrode 21 of the pair of external electrodes 20, the same applies to the second external electrode 22. As shown in Figure 8, a gap G also exists between the second connection bend portion 22b1 and the second land 62 of the second external electrode 22, and the solder 70 fills this gap G as well. Therefore, crack formation in the base portion 11 is similarly suppressed in the second external electrode 22.

[0053] The multilayer ceramic capacitor 1 according to the embodiment described above provides the following effects.

[0054] The multilayer ceramic capacitor 1 according to this embodiment comprises a component body 10 having a length L, and a pair of external electrodes 20 arranged at both ends of the component body 10 in the length L, wherein the component body 10 has a central outer peripheral portion 30 in at least a portion of the exposed part between the pair of external electrodes 20 that protrudes outward from the pair of external electrodes 20 in one direction perpendicular to the length L.

[0055] When mounting the multilayer ceramic capacitor 1 according to the embodiment onto a substrate 50, the central outer peripheral portion 30 comes into contact with the surface of the substrate 50 when the multilayer ceramic capacitor 1 is set in a predetermined mounting position on the substrate 50, creating a gap G between the external electrode 20 and the first land 61 and the second land 62. When the external electrode 20 is soldered to the first land 61 and the second land 62, the solder 70 fills the gap G. This allows a sufficient amount of solder 70 to be filled between the external electrode 20 and the first land 61 and the second land 62. Therefore, if the substrate 50 bends, the stress at that time is less likely to be transmitted to the base portion 11, and the occurrence of cracks in the base portion 11 can be suppressed.

[0056] In the multilayer ceramic capacitor 1 according to this embodiment, it is preferable that the central outer peripheral portion 30 protrudes 15 μm or more outward from the external electrode 20 in the direction described above.

[0057] This allows the gap G between the external electrode 20 and the first land 61 and the second land 62 to be 15 μm or more, so that a sufficient amount of solder 70 can be filled into this gap G. As a result, the effect of the solder 70 in blocking stress transmission from the substrate 50 to the base part 11 is sufficiently achieved, and the occurrence of cracks in the base part 11 can be suppressed.

[0058] In the multilayer ceramic capacitor 1 according to this embodiment, the central outer peripheral portion 30 is provided around the entire outer circumference of the component body 10.

[0059] As a result, regardless of which part of the central outer periphery 30 is positioned facing the substrate 50, a gap G can be maintained between the external electrodes 20 and the first land 61 and the second land 62. Therefore, there is no need to choose the orientation of the multilayer ceramic capacitor 1 when it is set on the substrate 50, simplifying the mounting process.

[0060] In the multilayer ceramic capacitor 1 according to this embodiment, the component body 10 has a base portion 11 including an internal electrode layer 14, and a central outer peripheral portion 30 is arranged on the surface of the base portion 11, and this central outer peripheral portion 30 includes at least one of ceramic and resin.

[0061] This allows the central outer periphery 30 to be easily formed in the desired position and shape. In particular, by forming the central outer periphery 30 with the same ceramic material as the dielectric ceramic layer 13, the base body 11 and the central outer periphery 30 can be manufactured by firing them simultaneously, thereby improving manufacturing efficiency.

[0062] The mounting structure according to the embodiment is a mounting structure for a multilayer ceramic capacitor 1 in which a pair of external electrodes 20 are connected to a first land 61 and a second land 62 arranged spaced apart from each other on the surface of a substrate 50, wherein the multilayer ceramic capacitor 1 has a component body 10 and a pair of external electrodes 20 arranged on the component body 10, the component body 10 is in contact with the substrate 50 and a gap G exists between each of the pair of external electrodes 20 and the substrate 50.

[0063] When the external electrode 20 is soldered to the first land 61 and the second land 62, the solder 70 fills the gap G. This allows a sufficient amount of solder 70 to be filled between the external electrode 20 and the first land 61 and the second land 62. Therefore, if the substrate 50 bends, the stress at that time is less likely to be transmitted to the base part 11, and the occurrence of cracks in the base part 11 can be suppressed.

[0064] In the mounting structure according to the embodiment, the gap G between each of the pair of external electrodes 20 and the substrate 50 is preferably 15 μm or more.

[0065] This allows for a sufficient amount of solder 70 to be filled into the gap G. As a result, the solder 70 effectively blocks stress transmission from the substrate 50 to the base part 11, thereby suppressing crack formation in the base part 11.

[0066] In the mounting structure according to the embodiment, the substrate 50 has a fiber direction extending in one direction, and it is preferable that the direction in which the pair of external electrodes 20 of the multilayer ceramic capacitor 1 are spaced apart from each other is parallel to the fiber direction. In the embodiment, the direction in which the pair of external electrodes 20 are spaced apart from each other is the length direction L.

[0067] A multilayer ceramic capacitor 1 is more susceptible to stress from a rigidity standpoint when subjected to stress that causes it to curve in the length direction L than when subjected to stress that causes it to curve in the width direction W. However, by positioning the multilayer ceramic capacitor 1 on the substrate 50 such that the length direction L is aligned with the fiber direction of the substrate 50, the stress on the multilayer ceramic capacitor 1 is reduced compared to when it is positioned in a direction intersecting the fiber direction, thanks to the rigidity provided by the fibers of the substrate 50. This improves the crack prevention effect.

[0068] Furthermore, the present invention is not limited to the embodiments described above, and any modifications, improvements, etc., that can achieve the objectives of the present invention are included within the scope of the present invention.

[0069] For example, the protrusions that cause the external electrodes 20 to float above the surface of the substrate 50 do not have to cover the entire outer circumference of the component body 10. For example, as shown in Figure 11, they may be present in only two locations: a first protrusion 31 on the first main surface 17a1 of the base body 11 and a second protrusion 32 on the second main surface 17a2 of the base body 11. In this case, the multilayer ceramic capacitor 1 is set on the substrate 50 so that either the first protrusion 31 or the second protrusion 32 is in contact with the surface of the substrate 50. Furthermore, it is also possible that only one of the first protrusion 31 or the second protrusion 32 is provided.

[0070] Furthermore, the protrusions may be limited to just two locations: a third protrusion 33 provided on the third side surface 15a of the base portion 11, and a fourth protrusion 34 provided on the fourth side surface 15b of the base portion 11. In this case, the multilayer ceramic capacitor 1 is set on the substrate 50 such that either the third protrusion 33 or the fourth protrusion 34 is in contact with the surface of the substrate 50. Moreover, it is also possible that only one of the third protrusion 33 or the fourth protrusion 34 is provided.

[0071] The multilayer ceramic capacitor 1 in the above embodiment is just one example of an electronic component, and the electronic components of this disclosure are not limited to this; other two-terminal electronic components such as thermistors and inductors can also be applied. [Explanation of symbols]

[0072] 1. Multilayer ceramic capacitor (electronic component) 10. Main body of parts 11. Body part 14 Internal electrode layer (internal electrode) 20 External electrode 21 First external electrode 22 Second external electrode 30 Center outer periphery (projection) 50 circuit boards 61. The first land (land) 62. The Second Land (Land) G Gap

Claims

1. An electronic component mounting structure in which each of a pair of external electrodes of an electronic component, which is a multilayer ceramic capacitor, is connected to a pair of lands arranged spaced apart from each other on the surface of a substrate, The aforementioned electronic component comprises a component body and a pair of external electrodes arranged on the component body. The main body of the component has a projection in at least a portion of the part exposed between the pair of external electrodes that protrudes outward from the pair of external electrodes in one direction perpendicular to the longitudinal direction, The aforementioned protrusion is made of resin that is provided around the entire outer circumference of the main body of the component, and protrudes 15 μm or more outward from the external electrode in the one direction. An electronic component mounting structure in which the protrusions provided on the entire outer circumference of the component body are in contact with the substrate, and a gap exists between each of the pair of external electrodes and the substrate, and the gap is filled with solder.

2. The mounting structure for electronic components according to claim 1, wherein the gap is 15 μm or more.

3. The substrate has a fiber direction that extends in one direction, The mounting structure for an electronic component according to claim 1 or 2, wherein the direction in which the pair of external electrodes are spaced apart from each other is arranged parallel to the fiber direction.

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