Mounting structure for electronic component

Abstract

Provided is a mounting structure for an electronic component, the structure enabling suppression of crack generation in the electronic component.　In a mounting structure (1) for an electronic component (10), external electrodes (16) each include an extension part (16c) provided so as to extend to at least a portion of each main surface (17a) and each lateral surface (17b). Assuming the direction in which a pair of lands (30) are arranged is the X direction, the direction in which the pair of lands (30) are separated from each other is the separation direction (X1), and the direction in which the pair of lands (30) oppose each other is the opposing direction (X2), an opposing-direction end part (40a) of solder (40) is located, in the X direction, at either a position between an extension-part end part (16e) of a land-opposing extension part (16d) and a separation-direction end part (16f) of the external electrode (16), or the position of the separation-direction end part (16f) of the external electrode (16).

Description

Mounting structure for electronic components

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

[0002] Conventionally, two-terminal electronic components such as multilayer ceramic capacitors and inductors have been mounted on a circuit board by soldering. Patent Document 1 discloses a mounting structure in which a pair of external electrodes provided at both ends of a multilayer ceramic capacitor in the longitudinal direction are connected to a pair of electrode pads provided on the board by soldering.

[0003] JP 2014-086606 A

[0004] When the ambient temperature changes during use of electronic devices, stress occurs in the electronic components due to differences in the linear expansion coefficients of the electronic components, solder, and substrate. Stress in electronic components can cause cracks to form at the interface between the element body and the external electrodes. Furthermore, if electronic components with such cracks are exposed to a humidity-resistant environment, the internal insulation resistance decreases, generating heat and potentially damaging the electronic device.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a mounting structure for electronic components that can suppress the occurrence of cracks in electronic components.

[0006] In order to solve the above-mentioned problem, the electronic component mounting structure of the present invention comprises: a component body having a pair of lands arranged opposite to each other with a space between them on a substrate, solder arranged on each of the lands, dielectric layers and internal electrode layers stacked together, the component body including a pair of main surfaces opposing each other in a stacking direction, a pair of side surfaces opposing each other in a width direction perpendicular to the stacking direction, and a pair of end surfaces opposing each other in a length direction perpendicular to the stacking direction and the width direction; and a pair of external electrodes arranged on each of the end surfaces, each of the external electrodes being connected to a corresponding land via the solder, wherein each of the external electrodes includes an extension portion extending to at least a part of each of the main surfaces and each of the side surfaces, and wherein, when the direction in which the pair of lands are aligned is defined as an X-direction, the direction in which the pair of lands are separated is defined as a separating direction, and the direction in which the pair of lands face each other is defined as a facing direction, the facing end of the solder is located, in the X-direction, either between the facing end of the extension portion and the facing end of the external electrode, or at the facing end of the external electrode.

[0007] According to the present invention, it is possible to provide a mounting structure for electronic components that can suppress the occurrence of cracks in electronic components.

[0008] FIG. 1 is a perspective view showing a multilayer ceramic capacitor as an electronic component applied to the electronic component mounting structure according to the first embodiment. FIG. 2 is a plan view showing the electronic component mounting structure according to the first embodiment. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the first embodiment. FIG. 5 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the second embodiment. FIG. 6 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the third embodiment. FIG. 7 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the fourth embodiment. FIG. 8 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the fifth embodiment. FIG. 9 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the sixth embodiment. FIG. 10 is a partially enlarged cross-sectional view showing a main portion of the electronic component mounting structure according to the seventh embodiment.

[0009] Hereinafter, embodiments will be described with reference to the drawings. (First Embodiment) (Multilayer Ceramic Capacitor) The structure of a multilayer ceramic capacitor 10 will be outlined with reference to Fig. 1. Fig. 1 shows a multilayer ceramic capacitor 10 as an electronic component applied to a mounting structure for an electronic component according to the first embodiment. The first embodiment is one form of a structure in which the multilayer ceramic capacitor 10 is mounted on a substrate.

[0010] The multilayer ceramic capacitor 10 has a generally rectangular parallelepiped shape as a whole and includes a component body 11 and a pair of external electrodes 16. The component body 11 has an internal layer portion 12 configured by alternately stacking a plurality of dielectric layers 121 and internal electrode layers 122.

[0011] In this specification, the direction in which the dielectric layers 121 and the internal electrode layers 122 are stacked is referred to as the "stacking direction T." The direction perpendicular to the stacking direction T is referred to as the "length direction L." The direction perpendicular to the stacking direction T and the length direction L is referred to as the "width direction W." The pair of external electrodes 16 are aligned in the length direction L.

[0012] The dimensions of the multilayer ceramic capacitor 10 include, for example, dimensions of 0.2 mm or more and 1.7 mm or less in the length direction L, 0.12 mm or more and 0.9 mm or less in the width direction W, and 0.12 mm or more and 0.9 mm or less in the stacking direction T, but are not limited to these.

[0013] The component body 11 has a generally rectangular parallelepiped shape and includes a pair of main surfaces 17 a facing each other in the stacking direction T, a pair of side surfaces 17 b facing each other in the width direction W, and a pair of end surfaces 17 c facing each other in the length direction L.

[0014] The component body 11 has an inner layer portion 12 therein. The inner layer portion 12 has a multilayer structure in which a plurality of internal electrode layers 122 and a plurality of dielectric layers 121 are alternately stacked in a stacking direction T. Four surfaces of the inner layer portion 12, on both sides in the width direction W and on both sides in the stacking direction T, are covered with outer dielectric ceramic layers 13 made of the same material as the dielectric ceramic layers.

[0015] (Internal electrode layer) The internal electrode layer 122 is formed of a metal material such as Ni, Cu, Ag, Pd, an Ag-Pd alloy, or Au, but is not limited to these metal materials and may be formed of other conductive materials.

[0016] (Dielectric Layer) The dielectric layer 121 and the outer dielectric ceramic layer 13 are made of, for example, a ceramic material containing barium titanate as a main component or other ceramic material with a high dielectric constant (for example, CaTiO ３ , SrTiO ３ , CaZrO ３ It is formed by firing a material containing, for example, tungsten, tungsten oxide, tungsten carbide ...

[0017] (External Electrodes) A ​​pair of external electrodes 16 are respectively arranged at both ends of the component body 11 in the longitudinal direction L. Each external electrode 16 covers a pair of end faces 17c of the component body 11. Note that each of the pair of external electrodes 16 may also be arranged on a portion of the pair of main faces 17a or a portion of the pair of side faces 17b. In the multiple internal electrode layers 122 in the inner layer portion 12, one side of the internal electrode layers adjacent in the stacking direction T is connected to one external electrode 16, and the other side is connected to the other external electrode. Each of the pair of external electrodes 16 has an end face 16a in the longitudinal direction L.

[0018] The external electrodes 16 are formed, for example, by a laminated film of a sintered metal layer and a plating layer. The sintered metal layer is formed by baking a paste of, for example, Cu, Ni, Ag, Pd, an Ag-Pd alloy, Au, etc. The plating layer is formed, for example, by a Ni plating layer covered with a Sn plating layer.

[0019] The multilayer ceramic capacitor 10 is manufactured, for example, by firing the component body 11 and then forming a pair of external electrodes 16 by baking, plating, etc. In some cases, a portion of the external electrodes 16 is fired simultaneously with the component body 11, and then a plating layer of the external electrodes 16 is formed.

[0020] (Mounting Structure) The mounting structure 1 of the first embodiment will be described with reference to Figures 2 and 3. In order to distinguish it from the mounting structures 1 of the other embodiments, the mounting structure 1 of the first embodiment will be referred to as a mounting structure 101. The same applies to the other embodiments.

[0021] 2 and 3, the mounting structure 101 of the first embodiment includes a substrate 20, a pair of lands 30 arranged opposite to and spaced apart from each other on the substrate 20, solder 40 at least partially arranged on each land 30, and a multilayer ceramic capacitor 10. The multilayer ceramic capacitor 10 is mounted on the substrate 20 by soldering.

[0022] (Substrate) The substrate 20 is formed in a sheet shape from an insulating material such as resin, glass, glass epoxy, paper phenol, or ceramics.

[0023] Wiring 33 is formed on the surface 20a of the substrate 20. The wiring 33 is discontinuous with a separation portion 21 sandwiched therebetween, and a pair of lands 30, which are part of the wiring 33 and connected to the external electrodes 16, are exposed on both sides of the separation portion 21. The pair of lands 30 are arranged spaced apart from each other on the surface 20a of the substrate 20. Therefore, the separation portion 21 can also be said to be the region between the pair of lands 30. The pair of lands 30 are arranged side by side so that their positions are the same in a direction perpendicular to the direction in which the lands 30 are arranged.

[0024] (Wiring and Lands) The wiring 33 including the lands 30 is formed by depositing a highly conductive metal such as Cu or Ag on the surface 20a of the substrate 20. Each of the pair of lands 30 has a rectangular shape in a plan view and has approximately the same shape and dimensions as each other.

[0025] (Separating direction and facing direction) In this specification, the direction perpendicular to the surface 20a of the substrate 20 is referred to as the "Z direction." The direction perpendicular to the Z direction and in which a pair of lands 30 are aligned is referred to as the "X direction." The direction perpendicular to the X direction and the Z direction is referred to as the "Y direction." Within the X direction, the direction in which the pair of lands 30 are separated is referred to as the "separating direction X1," and the direction in which the pair of lands 30 face each other is referred to as the "facing direction X2." Furthermore, "land thickness" refers to the dimension of the land 30 in the Z direction.

[0026] The peripheral edges of the pair of lands 30 in the X and Y directions are referred to as "peripheral edges 31." The edge of the peripheral edges 31 on the separation portion 21 side is referred to as "inner edges 31a." The inner edges 31a are linear and extend in the Y direction.

[0027] (Insulating Film) The surface 20a of the substrate 20 is covered with an insulating film 22. The insulating film 22 is made of an insulating material, for example, solder resist. However, the insulating material is not limited to this, and an insulating coating material for a substrate, mainly composed of a resin such as polyolefin resin, acrylic resin, or polyurethane resin, can be suitably used as the insulating material for the insulating film 22. The insulating film 22 extends onto each of the lands 30, and a portion of each land 30 near the peripheral edge 31 is covered with the insulating film 22. The peripheral edge 31 of each land 30 is covered with the insulating film 22. In the separation portion 21, the surface 20a of the substrate 20 is covered with the insulating film 22. In FIG. 2, the portion where the insulating film 22 is disposed is indicated by dot hatching.

[0028] (On-land insulating film and inter-separation insulating film) Note that the portion of the insulating film 22 arranged on the surface of each land 30 is referred to as the "on-land insulating film 22a," and the portion arranged in the region overlapping with the separation portion 21 as viewed in the Z direction is referred to as the "inter-separation insulating film 22b." Note that the insulating film 22 arranged in the separation portion 21 is included in the inter-separation insulating film 22b. If the inner edge 31a of the land 30 forms an inclined surface that slopes toward the substrate 20 as it moves toward the facing direction X2, the insulating film 22 arranged in the region overlapping with the inclined surface as viewed in the Z direction is included in the inter-separation insulating film 22b, but is not included in the on-land insulating film 22a. In this specification, the "thickness of the insulating film 22" means the dimension of the insulating film 22 in the Z direction.

[0029] The multilayer ceramic capacitor 10 mounted on the substrate 20 has a length direction L that is approximately aligned with the X direction, a width direction W that is approximately aligned with the Y direction, and a stacking direction T that is approximately aligned with the Z direction. This causes one main surface 17a of the component body 11 to face substantially parallel to the surface 20a of the substrate 20. Note that the multilayer ceramic capacitor 10 does not necessarily have to be mounted on the substrate 20 with the main surface 17a facing the substrate 20, and may be mounted on the substrate 20 with one side surface 17b facing the substrate 20.

[0030] In the multilayer ceramic capacitor 10, one external electrode 16 is connected to one land 30 via solder 40, and the other external electrode 16 is connected to the other land 30 via solder 40. As shown in Fig. 3, the end face 16a of each external electrode 16 is almost covered with solder 40. Note that the end face 16a of each external electrode 16 may be partially covered with solder 40. The multilayer ceramic capacitor 10 is arranged so that its center in the width direction W substantially coincides with the center of each land 30 in the width direction W.

[0031] (Extension Portion of External Electrode) Each of the pair of external electrodes 16 includes a flat end surface covering portion 16b that covers the end surface 17c of the component body 11, and an extension portion 16c that extends from the end surface covering portion 16b in the facing direction X2 and is disposed on a portion of the pair of principal surfaces 17a and the pair of side surfaces 17b. The extension portion 16c covers only a portion of each of the principal surfaces 17a and the side surfaces 17b on the end surface 17c side of each surface. The extension portion 16c has an overall rectangular cylindrical shape. The end of the extension portion 16c on the facing direction X2 side forms the boundary portion between the external electrode 16 and the component body 11 (hereinafter referred to as the "boundary portion 15"). Note that the extension portion 16c does not necessarily have to have an overall rectangular cylindrical shape. The extension portion 16c does not need to extend to all of the main surfaces 17a and side surfaces 17b, but only needs to extend to at least one of the main surfaces 17a and side surfaces 17b that faces the substrate 20.

[0032] (Land-facing extension portion and extension portion end portion) The extension portion 16c covering one of the main surfaces 17a of the component body 11 facing the substrate 20 is connected to the land 30 via solder 40. Of the two main surfaces 17a of the component body 11, the extension portion 16c covering one of the main surfaces 17a facing the substrate 20 and connected to the land 30 directly or via the solder 40 is called the land-facing extension portion 16d.

[0033] The end of the land-facing extending portion 16d in the facing direction X2 is referred to as the extending portion end 16e. The extending portion end 16e (boundary portion 15) is located further in the separation direction X1 than the inner edge 31a of the land 30 connected to the land-facing extending portion 16d.

[0034] The end portion (boundary portion 15) of the land facing extension portion 16d on the facing direction X2 side may be located at a position closer to the facing direction X2 than the inner edge 31a of the land 30 connected to the land facing extension portion 16d or at a position substantially coincident with the inner edge 31a. In this case, the land on-surface insulating film 22a may be located between the land facing extension portion 16d and the land 30, or the land on-surface insulating film 22a may not be provided. This configuration will be described later.

[0035] (Solder End) The position of the opposing end 40a will be described with reference to Fig. 4. Fig. 4 is a partially enlarged cross-sectional view showing a main part of the mounting structure 101 of the multilayer ceramic capacitor 10 according to the first embodiment. In the mounting structure 101 of the first embodiment, the solder 40 does not extend beyond the land opposing extension 16d to the component body 11. In other words, the solder 40 does not contact the component body 11.

[0036] (Extended portion end and separating direction end) The end of the land-facing extending portion 16d in the facing direction X2 is referred to as the extended portion end 16e. The end of the external electrode 16 in the separating direction X1 is referred to as the separating direction end 16f. The separating direction end 16f refers to the portion of the end surface 16a of the external electrode 16 in the longitudinal direction L that is located closest to the separating direction X1.

[0037] (Solder End) The end of the solder 40 on the land 30 in the facing direction X2 is referred to as a facing direction end 40a.

[0038] (Position of Solder End) In the mounting structure 101 of the first embodiment, the facing end 40a is located either between the extending portion end 16e and the separating end 16f or at the separating end 16f in the X direction.

[0039] In the mounting structure 101 of the first embodiment, the facing end 40a is located either between the extension end 16e and the separating end 16f or on the separating end 16f.

[0040] By positioning the opposing direction end 40 a in this position, the solder 40 does not extend beyond the extending portion end 16 e and the extending portion end 16 e in the opposing direction X2, thereby preventing the solder 40 from coming into contact with the component body 11.

[0041] (Insulating Film End) Next, the arrangement of the insulating film 22 will be described. The end of the insulating film 22 in the separation direction X1 is referred to as the insulating film end 22c. In the example shown in FIG. 4, the insulating film end 22c contacts the facing direction end 40a. By positioning the insulating film end 22c on the extension-portion end 16e, between the extension-portion end 16e and the separating direction end 16f, or on the separating direction end 16f, the facing direction end 40a can be prevented from being positioned on the extension-portion end 16e or from exceeding the extension-portion end 16e. As a result, contact of the solder 40 with the component body 11 can be reliably prevented.

[0042] Next, a preferred X-direction position of the facing end 40a on the land 30 will be described. As shown in FIG. 4 , the range from the extension-portion end 16e to the separating-direction end 16f is defined as range R1. The length of range R1 is defined as 100. In range R1, the position of the extension-portion end 16e is defined as 0, and the position of the separating-direction end 16f is defined as 100. The position of the facing end 40a in range R1 satisfies the relationship 100≦position of the facing end 40a<0. That is, the facing end 40a is located either between the extension-portion end 16e and the separating-direction end 16f or on the separating-direction end 16f. This ensures electrical connection between the land-facing extension 16d and the land 30 while reliably preventing the solder 40 from contacting the component body 11.

[0043] Preferably, the position of the opposing end 40a in the range R1 satisfies 100≦the position of the opposing end 40a≦5 (range R2). Also, the position of the end face 17c in the range R1 preferably satisfies 55≦the position of the end face 17c≦5. Note that the numbers 5, 30, etc. relating to the range R1 shown in FIG. 4 indicate approximate positions.

[0044] More preferably, the position of the opposing end 40a satisfies 70≦the position of the opposing end 40a≦5 in the range R1 (range R3). This makes it easier for the solder 40 to cover the portion of the land opposing extension 16d that is thick in the stacking direction T. Even more preferably, the position of the opposing end 40a satisfies 30≦the position of the opposing end 40a≦5 in the range R1 (range R4). This makes it possible to prevent a decrease in the fixing strength of the solder 40.

[0045] (Solder Material) The type of solder 40 is not particularly limited as long as it has properties that are compatible with each external electrode 16 and each land 30, and may be, for example, Sn-Pb based solder, Sn-Ag-Cu based solder, Sn-Cu based solder, Sn-Bi based solder, etc.

[0046] (Cracks) Thermal shock or the like can cause stress to be applied to the sintered ceramic body near the tip of the external electrode 16. In this case, cracks may occur in the component body 11, starting from the boundary 15 between the edge of the land-facing extension 16d of the external electrode 16 and the component body 11. The area where such cracks are likely to occur is shown by the dotted line box BA in Figure 3.

[0047] Therefore, it is preferable that the solder 40 does not extend beyond the land-facing extension 16d and reach the component body 11. It is also preferable that the solder 40 does not contact the component body 11. In this case, stress is less likely to be applied to the boundary portion 15, thereby suppressing the occurrence of cracks. In addition to stress caused by thermal shock, stress caused by bending of the substrate 20 is also less likely to act on the boundary portion 15.

[0048] In the first embodiment, it is preferable that the thickness of the land insulating film 22 a be adjusted appropriately according to the desired thickness of the solder 40 on the land 30 .

[0049] The thickness of the insulating film 22, the thickness of the land 30, and the thickness of the solder 40 arranged on the land 30 are measured, for example, on a cross section obtained by cutting the mounting structure 101 of the first embodiment parallel to the X and Z directions so as to pass through the center of the multilayer ceramic capacitor 10 in the Y direction. The thickness value of the solder 40 is determined, for example, by measuring the thickness of the solder 40 at multiple (e.g., three) positions arranged at equal intervals in the X direction on the cross section and averaging the obtained values. The same applies to the insulating film 22 and the land 30.

[0050] In the first embodiment, the soldering using the solder 40 is performed by, for example, reflow. That is, the multilayer ceramic capacitor 10 can be reflow-mounted on the substrate 20. A method for mounting the multilayer ceramic capacitor 10 will be described below.

[0051] First, prior to soldering, an insulating film 22 is disposed on the substrate 20. The insulating film 22 is disposed, for example, so as to cover a portion of the land 30, including the peripheral edge portion 31. Next, a paste-like solder material is applied to the area of ​​the land 30 that is not covered by the insulating film 22. Next, the multilayer ceramic capacitor 10 is disposed in a predetermined position on the land 30. Then, as the solder material solidifies, the external electrodes 16 and the lands 30 are connected by solder 40.

[0052] Second Embodiment Next, a second embodiment will be described with reference to Fig. 5. The second embodiment is a partial modification of the first embodiment described above. Therefore, in the reference drawings, components similar to those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted, with only the differences being mainly described.

[0053] The mounting structure 103 of the second embodiment differs from the mounting structure 101 of the first embodiment in the position of the facing end 40a of the solder 40. In the mounting structure 101 of the first embodiment shown in FIG. 4, the facing end 40a was located between the extending portion end 16e and the separating end 16f in the X direction. In the mounting structure 101 of the first embodiment, the insulating film end 22c was located between the extending portion end 16e and the separating end 16f in the X direction. In the mounting structure 103 of the second embodiment, the insulating film end 22c is located at the extending portion end 16e in the X direction. The facing end 40a is located so as to face the insulating film end 22c in the X direction.

[0054] In the second embodiment, the above-described structure can prevent the solder 40 from coming into contact with the component body 11 .

[0055] 5, the insulating film 22 may have a portion at an insulating film end 22c where the insulating film 22 protrudes upward, thereby contacting the extending portion end 16e. This protruding portion is called an insulating film protrusion 22d. The term "upward" refers to a direction perpendicular to the surface 20a of the substrate 20 and away from the surface 20a.

[0056] The provision of the insulating film protrusion 22 d more reliably prevents the solder 40 from coming into contact with the component body 11 .

[0057] Third Embodiment Next, a third embodiment will be described with reference to Fig. 6. The third embodiment is a partial modification of the first embodiment described above. Therefore, in the reference drawings, components similar to those in the first embodiment are denoted by the same reference numerals, and a description thereof will be omitted, with only the differences being mainly described.

[0058] The mounting structure 104 of the third embodiment differs from the mounting structure 101 of the first embodiment in the position of the facing end 40a of the solder 40. In the mounting structure 101 of the first embodiment shown in Fig. 4, the facing end 40a is located between the extension end 16e and the separating end 16f in the X direction. In the mounting structure 104 of the third embodiment, as shown in Fig. 6, the facing end 40a is located near the end face 17c in the X direction. This will be explained below.

[0059] (Extended portion flat portion) The surface of the land-facing extending portion 16d is called the extended portion surface 16h. The surface of the land 30 is called the land surface 30a. In the land-facing extending portion 16d, the portion where the extended portion surface 16h is parallel to the land surface 30a is called the extended portion flat portion 16g. In Figure 6, the position of the end of the extended portion flat portion 16g in the facing direction X2 is indicated by position D. The position of the end of the extended portion flat portion 16g in the separating direction X1 is indicated by position E.

[0060] In the mounting structure 104 of the third embodiment, the extension-portion flat portion 16g of the land-facing extension portion 16d contacts the land 30 without the solder 40. Between positions D and E, there is no solder 40 between the extension-portion surface 16h and the land surface 30a.

[0061] The opposing end 40a of the solder 40 is located at position E at the end of the flat portion 16g of the extension in the separation direction X1.

[0062] In the third embodiment, the opposing end 40 a is located on the separation direction X1 side of the portion where the flat portion 16 g of the extension portion faces the land 30. This reliably prevents the solder 40 from coming into contact with the component body 11.

[0063] The electrical continuity between the external electrode 16 and the land 30 is ensured by connecting the end face 16 a of the external electrode 16 to the land 30 with solder 40 .

[0064] Furthermore, in the mounting structure 104 of the third embodiment, for example, when the external electrode 16 includes a plating layer, the formation of the mounting structure 104 is facilitated by forming a tin plating layer on the end face 16a of the external electrode 16 and not forming a tin plating layer on the flat portion 16g of the extending portion of the external electrode 16.

[0065] (Fourth Embodiment) Next, a fourth embodiment will be described with reference to Fig. 7. The fourth embodiment is a partial modification of the first embodiment described above. Therefore, in the reference drawings, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being mainly described.

[0066] (Land Upper End) The mounting structure 105 of the fourth embodiment differs from the mounting structure 101 of the first embodiment in the position of the land 30. The upper end of the inner edge 31a of the land 30 is called the land upper end 31b. As described above, "upper" refers to a direction perpendicular to the surface 20a of the substrate 20 and away from the surface 20a. The position of the land upper end 31b in the X direction is indicated by position P.

[0067] In the mounting structure 101 of the first embodiment shown in Fig. 4, the land upper end 31b is located further in the facing direction X2 than the extension portion end 16e. In the mounting structure 105 of the fourth embodiment, as shown in Fig. 7, the land upper end 31b is located at the position of the extension portion end 16e.

[0068] Even when the upper end 31b of the land is located at the position of the extension portion end 16e, the opposing end 40a can be positioned either between the extension portion end 16e and the separating direction end 16f or on the separating direction end 16f, as in the mounting structure 101 of the first embodiment.

[0069] For example, the insulating film end 22c of the land insulating film 22a is placed at the desired position of the opposing end 40a. Then, the solder 40 is provided so that the opposing end 40a contacts the insulating film end 22c. This allows the opposing end 40a to be placed at the desired position.

[0070] The distance in the X direction between the land upper end 31b and the insulating film end 22c is defined as the insulating film distance on the land. The insulating film distance on the land is the length of the insulating film 22a on the land in the X direction. The insulating film distance on the land in the mounting structure 105 of the fourth embodiment shown in FIG. 7 is shorter than the insulating film distance on the land in the mounting structure 101 of the first embodiment shown in FIG. 4. That is, in the mounting structure 105 of the fourth embodiment, the length of the insulating film 22a on the land in the X direction is shorter than that in the mounting structure 101 of the first embodiment. Therefore, in the mounting structure 105 of the fourth embodiment, it is possible to suppress variations in the bonding strength between the multilayer ceramic capacitor 10 and the substrate 20 after mounting.

[0071] Fifth Embodiment Next, a fifth embodiment will be described with reference to Fig. 8. The fifth embodiment is a partial modification of the first embodiment and the fifth embodiment described above. Therefore, in the reference drawings, the same components as those in the first embodiment and the fifth embodiment are denoted by the same reference numerals, and a description thereof will be omitted, with only the differences being mainly described.

[0072] The mounting structure 106 of the fifth embodiment differs from the mounting structure 101 of the first embodiment and the mounting structure 105 of the fourth embodiment in the position of the lands 30 .

[0073] In the first embodiment shown in Fig. 4, the land upper end 31b is located closer to the facing direction X2 than the extension portion end 16e. In the fourth embodiment, the land upper end 31b is located at the position of the extension portion end 16e. In the fifth embodiment, as shown in Fig. 8, the land upper end 31b is located closer to the extension portion end 16e in the separation direction X1. In the fifth embodiment, the distance in the X direction between two opposing lands 30 is shorter than the distance in the X direction between two opposing extension portion ends 16e.

[0074] In the mounting structure 106 of the fifth embodiment, the facing end 40 a is unlikely to reach the extending portion end 16 e along the land surface 30 a. This is because the land surface 30 a is located only up to a position beyond the extending portion end 16 e in the separation direction X1. Therefore, the mounting structure 106 of the fifth embodiment makes it easy to prevent the solder 40 from contacting the component body 11.

[0075] Furthermore, in the mounting structure 106 of the fifth embodiment, the insulating film end 22 c of the insulating film 22 is positioned at the desired position of the facing end 40 a. The facing end 40 a is unlikely to extend beyond the insulating film end 22 c. Therefore, the mounting structure 106 of the fifth embodiment can more reliably prevent the solder 40 from contacting the component body 11.

[0076] Sixth Embodiment Next, a sixth embodiment will be described with reference to Fig. 9. The sixth embodiment is a partial modification of the fifth embodiment described above. Therefore, in the reference drawings, the same components as those in the fifth embodiment are denoted by the same reference numerals, and their description will be omitted, with only the differences being mainly described.

[0077] The mounting structure 107 of the sixth embodiment differs from the mounting structure 106 of the fifth embodiment in the presence or absence of an insulating film 22. In the mounting structure 106 of the fifth embodiment shown in Fig. 8, the insulating film 22 (inter-separation insulating film 22b) is arranged in the separation portion 21. In the mounting structure 107 of the sixth embodiment, as shown in Fig. 9, the insulating film 22 is not arranged in the separation portion 21. The portion where the inter-separation insulating film 22b was arranged in the mounting structure 106 of the fifth embodiment is now a gap portion 23.

[0078] In the mounting structure 107 of the sixth embodiment, the facing direction end 40a does not contact the insulating film 22 in the facing direction X2. Therefore, the solder 40 may wet and spread along the land facing extension 16d. The wet and spread portion of the solder 40 is called a wet spreading portion 40c. In the example shown in FIG. 9, the wet spreading portion 40c of the solder 40 is formed near the facing direction end 40a.

[0079] In the mounting structure 107 of the sixth embodiment, the facing end 40a is also located either between the extending-portion end 16e and the separating-direction end 16f or on the separating-direction end 16f, because the land upper end 31b is located at a position spaced a predetermined distance from the extending-portion end 16e in the separating direction X1.

[0080] In the mounting structure 107 of the sixth embodiment, by arranging the land upper end portion 31b at a predetermined position, it is possible to prevent the solder 40 from contacting the component body 11 without arranging the insulating film 22 on the inter-separation insulating film 22b. In other words, in the mounting structure 107 of the sixth embodiment, it is possible to prevent the solder 40 from contacting the component body 11 without giving special consideration to the arrangement of the insulating film 22.

[0081] Seventh Embodiment Next, a seventh embodiment will be described with reference to Fig. 10. The seventh embodiment is a partial modification of the fifth and sixth embodiments described above. Therefore, in the reference drawings, components similar to those of the fifth and sixth embodiments are denoted by the same reference numerals, and a description thereof will be omitted, with only the differences being mainly described.

[0082] Comparison with Fifth Embodiment The mounting structure 108 of the seventh embodiment will be described in comparison with the mounting structure 106 of the fifth embodiment. The mounting structure 108 of the seventh embodiment differs from the mounting structure 106 of the fifth embodiment in the length of the insulating film 22 that is present from the extension portion end 16 e in the separation direction X1.

[0083] The distance in the X direction from the extension portion end 16e to the insulating film end 22c is defined as the insulating film extension portion distance. The insulating film extension portion distance in the mounting structure 108 of the seventh embodiment shown in FIG. 10 is shorter than the insulating film extension portion distance in the mounting structure 106 of the fifth embodiment shown in FIG. 8. In the mounting structure 106 of the fifth embodiment shown in FIG. 8, the insulating film end 22c extends beyond the extension portion end 16e to the land upper end 31b. In the mounting structure 108 of the seventh embodiment shown in FIG. 10, the insulating film end 22c extends beyond the extension portion end 16e but only to the point just before reaching the land upper end 31b. Therefore, the insulating film extension portion distance in the mounting structure 108 of the seventh embodiment is shorter than the insulating film extension portion distance in the mounting structure 106 of the fifth embodiment.

[0084] In the mounting structure 108 of the seventh embodiment, the insulating film end 22c is positioned further in the facing direction X2. Therefore, the facing direction end 40a is also positioned further in the facing direction X2. As a result, the distance in the X direction over which the solder 40 contacts the land facing extension 16d becomes longer.

[0085] Regarding the distance in the X direction from the opposing end 40a to the end face 17c, the distance in the mounting structure 108 of the seventh embodiment shown in Figure 10 is longer than the distance in the mounting structure 106 of the fifth embodiment shown in Figure 8.

[0086] In this way, in the mounting structure 108 of the seventh embodiment, the distance from the extension end 16 e to the insulating film end 22 c is shortened, thereby increasing the distance from the opposing end 40 a to the end face 17 c, thereby reducing the electrical resistance between the external electrode 16 and the land 30.

[0087] In the mounting structure 108 of the seventh embodiment, the insulating film end 22 c is disposed beyond the extension end 16 e in the separation direction X1. This prevents the solder 40 from coming into contact with the component body 11.

[0088] (Comparison with Sixth Embodiment) Next, a mounting structure 108 of the seventh embodiment will be described in comparison with the mounting structure 107 of the sixth embodiment. The mounting structure 108 of the seventh embodiment differs from the mounting structure 107 of the sixth embodiment in the presence or absence of an insulating film 22. In the mounting structure 107 of the sixth embodiment shown in FIG. 9, the insulating film 22 is not disposed in the separation portion 21. In the mounting structure 108 of the seventh embodiment shown in FIG. 10, the insulating film 22 (inter-separation portion insulating film 22b) is disposed in the separation portion 21.

[0089] 10 , the inter-separation insulating film 22 b in the mounting structure 108 of the seventh embodiment is formed beyond the extension portion end 16 e in the separation direction X1. This inter-separation insulating film 22 b prevents the solder 40 from being located at the extension portion end 16 e and from contacting the component body 11 beyond the extension portion end 16 e.

[0090] Therefore, in the mounting structure 108 of the seventh embodiment, the land upper end 31b can be positioned further in the facing direction X2 than in the mounting structure 107 of the sixth embodiment. This is because, in the mounting structure 108 of the seventh embodiment, even if the solder 40 spreads in the facing direction X2 starting from the land upper end 31b, the spreading of the solder 40 is stopped by the inter-separation insulating film 22b before it comes into contact with the component body 11.

[0091] By positioning the land upper end 31b further in the facing direction X2, the length in the X direction over which the solder 40 contacts the land facing extension 16d can be increased. The distance in the X direction from the facing end 40a to the end face 17c in the mounting structure 108 of the seventh embodiment shown in Fig. 10 is longer than the distance in the mounting structure 107 of the sixth embodiment shown in Fig. 9. The increase in the distance in the X direction from the facing end 40a to the end face 17c can reduce the electrical resistance between the external electrode 16 and the land 30.

[0092] Furthermore, by positioning the land upper end 31b further in the opposing direction X2, alignment when mounting the multilayer ceramic capacitor 10 on the substrate 20 becomes easier.

[0093] The present invention is not limited to the above-described embodiment, and modifications and improvements within the scope of achieving the object of the present invention are included in the present invention.

[0094] For example, the multilayer ceramic capacitor 10 in the above embodiment is an example of an electronic component, but the electronic component is not limited to this, and other two-terminal electronic components such as inductors are also applicable. For example, in the case of an inductor, the component body is made of magnetic ceramics or the like.

[0095] The present invention also includes the following combinations: <1> An electronic component comprising: a component body having a pair of lands arranged opposite to and spaced apart from each other on a substrate, solder arranged on each of the lands, laminated dielectric layers and internal electrode layers, the component body including a pair of main surfaces opposing each other in a lamination direction, a pair of side surfaces opposing each other in a width direction perpendicular to the lamination direction, and a pair of end surfaces opposing each other in a length direction perpendicular to the lamination direction and the width direction, and a pair of external electrodes arranged on each of the end surfaces, each of the external electrodes being connected to a corresponding one of the lands via the solder, wherein each of the external electrodes includes an extending portion extending to at least a portion of each of the main surfaces and each of the side surfaces, and wherein, assuming that the direction in which the pair of lands are aligned is an X-direction, the direction in which the pair of lands are separated is a separating direction, and the direction in which the pair of lands face each other is a facing direction, an opposing end of the solder is located either between the opposing end of the extending portion and the separating end of the external electrode or the separating end of the external electrode in the X-direction.

[0096] <2> The mounting structure of the electronic component of <1>, wherein the distance in the X direction between the opposing end of the extension portion and the opposing end of the solder is 5% or more and 100% or less of the distance in the X direction between the opposing end of the extension portion and the end face.

[0097] <3> The mounting structure of an electronic component according to <1> or <2>, further comprising an insulating film disposed on the land, wherein an end of the insulating film in a spaced-apart direction is located, in the X direction, at any one of an end of the extension in a facing direction, a portion between the end of the extension in a facing direction and an end of the external electrode in a spaced-apart direction, and an end of the external electrode in a spaced-apart direction.

[0098] <4> An electronic component mounting structure according to any one of <1> to <3>, which has an insulating film placed on the land, and in which the opposing end of the solder and the separating end of the insulating film are in contact.

[0099] <5> A mounting structure for an electronic component according to any one of <1> to <4>, which has an insulating film arranged on the substrate, and the end of the insulating film in the separating direction is located, in the X direction, at either the end of the extending portion in the facing direction, between the end of the extending portion in the facing direction and the end of the external electrode in the separating direction, or at the end of the external electrode in the separating direction.

[0100] <6> An electronic component mounting structure according to any one of <1> to <5>, which has an insulating film placed on the substrate, and in which the opposing end of the solder and the separating end of the insulating film are in contact with each other.

[0101] <7> An electronic component comprising: a component body having a pair of lands arranged opposite to each other with a gap between them on a substrate, solder respectively arranged on the lands, dielectric layers and internal electrode layers stacked together, the component body including a pair of main surfaces opposing each other in a stacking direction, a pair of side surfaces opposing each other in a width direction perpendicular to the stacking direction, and a pair of end surfaces opposing each other in a length direction perpendicular to the stacking direction and the width direction, and a pair of external electrodes respectively arranged on each of the end surfaces, each of the external electrodes being connected to each of the lands via the solder, wherein each of the external electrodes includes an extension portion extending to at least a part of each of the main surfaces and each of the side surfaces, and wherein, when the direction in which the pair of lands are aligned is defined as an X direction, the direction in which the pair of lands are separated is defined as a separating direction, and the direction in which the pair of lands face each other is defined as a facing direction, an end of the solder in the facing direction is located either between the end surface and an end of the external electrode in the separating direction, or at any one of the ends of the external electrode in the separating direction, in the X direction.

[0102] REFERENCE SIGNS LIST 1 Mounting structure 10 Multilayer ceramic capacitor (electronic component) 16 External electrode 16c Extension portion 16d Land facing extension portion 16e Extension portion end portion 16f Separating direction end portion 16g Extension portion flat portion 17c End surface 22 Insulating film 22c Insulating film end portion 30 Land 31 Peripheral edge portion 31b Land upper end portion 40 Solder 40a Opposing direction end portion X1 Separating direction X2 Opposing direction

Claims

1. a pair of lands arranged opposite to and spaced apart from each other on the substrate; solder disposed on each of the lands; an electronic component having a component body having laminated dielectric layers and internal electrode layers, the component body including a pair of main surfaces opposing each other in a lamination direction, a pair of side surfaces opposing each other in a width direction perpendicular to the lamination direction, and a pair of end faces opposing each other in a length direction perpendicular to the lamination direction and the width direction; and a pair of external electrodes respectively disposed on each of the end faces, each of the external electrodes being connected to a corresponding one of the lands via the solder; each of the external electrodes includes an extension portion extending to at least a part of the main surface and the side surface; If the direction in which the pair of lands are aligned is defined as the X direction, the direction in which the pair of lands are separated is defined as the separating direction, and the direction in which the pair of lands face each other is defined as the facing direction, then: the opposing end of the solder is located either between the opposing end of the extension and the separating end of the external electrode or at the separating end of the external electrode in the X direction; Mounting structure for electronic components.

2. a distance in the X direction between an end portion of the extension portion in the facing direction and an end portion of the solder in the facing direction is 5% or more and 100% or less of a distance in the X direction between the end portion of the extension portion in the facing direction and the end surface; The electronic component mounting structure according to claim 1 .

3. an insulating film disposed on the land; the insulating film has a separation-direction end portion located at any one of the opposing-direction end portion of the extension portion, the portion between the opposing-direction end portion of the extension portion and the separation-direction end portion of the external electrode, and the separation-direction end portion of the external electrode, in the X direction; 3. The electronic component mounting structure according to claim 1 or 2.

4. an insulating film disposed on the land; an end portion of the solder in the facing direction and an end portion of the insulating film in the separating direction are in contact with each other; 3. The electronic component mounting structure according to claim 1 or 2.

5. an insulating film disposed on the substrate; the insulating film has a separation-direction end portion located at any one of the opposing-direction end portion of the extension portion, the portion between the opposing-direction end portion of the extension portion and the separation-direction end portion of the external electrode, and the separation-direction end portion of the external electrode, in the X direction; 3. The electronic component mounting structure according to claim 1 or 2.

6. an insulating film disposed on the substrate; an end portion of the solder in the facing direction and an end portion of the insulating film in the separating direction are in contact with each other; 3. The electronic component mounting structure according to claim 1 or 2.

7. a pair of lands arranged opposite to and spaced apart from each other on the substrate; solder disposed on each of the lands; an electronic component having a component body having laminated dielectric layers and internal electrode layers, the component body including a pair of main surfaces opposing each other in a lamination direction, a pair of side surfaces opposing each other in a width direction perpendicular to the lamination direction, and a pair of end faces opposing each other in a length direction perpendicular to the lamination direction and the width direction; and a pair of external electrodes respectively disposed on each of the end faces, each of the external electrodes being connected to a corresponding one of the lands via the solder; Equipped with each of the external electrodes includes an extension portion extending to at least a part of the main surface and the side surface; If the direction in which the pair of lands are aligned is defined as the X direction, the direction in which the pair of lands are separated is defined as the separating direction, and the direction in which the pair of lands face each other is defined as the facing direction, then: the opposing end of the solder is located either between the end surface and the separating end of the external electrode or at the separating end of the external electrode in the X direction; 3. The electronic component mounting structure according to claim 1 or 2.