Electronic component mounting structure

Abstract

The present invention provides an electronic component mounting structure capable of suppressing cracks from occurring in the electronic component when a substrate is bent, the structure comprising: a pair of connection pads (30) arranged on a substrate (20) to be spaced apart from each other; solder (40) respectively arranged on the connection pads; and a laminated ceramic capacitor (10) as an electronic component, comprising a component body having a length direction and a pair of external electrodes arranged at both ends of the component body in the length direction, the pair of external electrodes being connected to the pair of connection pads via solder, and when the separation direction of the pair of connection pads is set to the X direction and the direction orthogonal to the X direction is set to the Y direction, if the width dimension of the connection pad along the Y direction is set to c, the dimension of the external electrode in the X direction is set to e, and the gap between the connection pad and the external electrode is set to Gap, the following formula is satisfied. 3.4<(c×e) / Gap<258.8…(1)

Description

Technical Field

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

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

[0003] Prior Art Literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2014-086606

[0006] In such a mounting structure of a multilayer ceramic capacitor, the substrate may be warped, causing cracks to form in the main body of the electronic component starting from the boundary between the external electrode on the outer surface and the multilayer body, and countermeasures must be taken. Summary of the invention

[0007] Problem that the invention aims to solve

[0008] Therefore, an object of the present invention is to provide an electronic component mounting structure capable of suppressing the occurrence of cracks in the electronic component when a substrate is deflected.

[0009] Technical solutions to solve problems

[0010] The present invention is an electronic component mounting structure, comprising: a pair of connection pads, which are arranged on a substrate to be separated from each other; solder, which is respectively arranged on the connection pads; and an electronic component, which comprises a component body having a length direction and a pair of external electrodes arranged at both ends of the component body in the length direction, wherein the pair of external electrodes are respectively connected to the pair of connection pads via the solder. When the separation direction of the pair of connection pads is set to the X direction and the direction orthogonal to the X direction is set to the Y direction, if the width dimension of the connection pad along the Y direction is set to c, the dimension of the external electrode in the X direction is set to e, and the gap between the connection pad and the external electrode is set to Gap, the following formula (1) is satisfied.

[0011] 3.4<(c×e) / Gap<258.8…(1)

[0012] Effects of the Invention

[0013] According to the present invention, it is possible to provide an electronic component mounting structure capable of suppressing the occurrence of cracks in the electronic component when a substrate is deflected. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a perspective view of a multilayer ceramic capacitor as an electronic component applied to the mounting structure according to the first embodiment.

[0015] Figure 2 It is a plan view showing the mounting structure according to the first embodiment.

[0016] Figure 3 yes Figure 2 III-III sectional view.

[0017] Figure 4 This is a partially enlarged cross-sectional view showing a main part of the mounting structure according to the first embodiment.

[0018] Figure 5 It is a plan view showing the mounting structure according to the second embodiment.

[0019] Figure 6 yes Figure 5 VI-VI sectional view.

[0020] Figure 7 It is a side view schematically showing the test method of the embodiment.

[0021] Figure 8 It is a graph showing the relationship between the deflection amount and (c×e) / Gap based on the results of the examples.

[0022] Description of Reference Numerals

[0023] 1, 2: Installation structure;

[0024] 10: Multilayer ceramic capacitors (electronic components);

[0025] 11: Component body;

[0026] 16: external electrode;

[0027] 16a: end surface of the external electrode;

[0028] 20: substrate;

[0029] 30: connection plate;

[0030] 31: inner end edge of the connecting plate;

[0031] 31a: end of the connection plate;

[0032] 32: outer end edge of the connecting plate;

[0033] 40: solder;

[0034] 50: adhesive;

[0035] 60: Solder adhesion inhibitor. DETAILED DESCRIPTION

[0036] Hereinafter, embodiments will be described with reference to the drawings.

[0037] (First embodiment)

[0038] Figure 1 A multilayer ceramic capacitor 10 is shown as an electronic component according to a first embodiment. The first embodiment is one form of a structure in which the multilayer ceramic capacitor 10 is mounted on a substrate.

[0039] The multilayer ceramic capacitor 10 has a substantially rectangular parallelepiped shape as a whole. The multilayer ceramic capacitor 10 includes a component body 11 and a pair of external electrodes 16. Figure 1 As shown, the multilayer ceramic capacitor 10 and the component body 11 have a common longitudinal direction L, a width direction W perpendicular to the longitudinal direction L, and a thickness direction T perpendicular to the longitudinal direction L and the width direction W, respectively.

[0040] Examples of the dimensions of the multilayer ceramic capacitor 10 include, but are not limited to, 0.2 mm to 1.7 mm in the length direction L, 0.12 mm to 0.9 mm in the width direction W, and 0.12 mm to 0.9 mm in the thickness direction T.

[0041] The component body 11 has a pair of main surfaces 17 a facing each other in the thickness 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.

[0042] 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 (not shown) and a plurality of inner dielectric ceramic layers are alternately stacked in the thickness direction T. The inner layer portion 12 is covered on both sides in the width direction W and on four sides in the thickness direction T by an outer dielectric ceramic layer 13 made of the same material as the above-mentioned dielectric ceramic layer.

[0043] The internal electrode layer constituting the inner layer portion 12 is formed of a metal material represented by, for example, Ni, Cu, Ag, Pd, Ag-Pd alloy, Au, etc., but is not limited to these metal materials and may be formed of other conductive materials.

[0044] The inner dielectric ceramic layer and the outer dielectric ceramic layer 13 constituting the inner layer portion 12 are formed by sintering a ceramic material mainly composed of barium titanate or other high dielectric constant ceramic materials (for example, a ceramic material mainly composed of CaTiO3, SrTiO3, CaZrO3, etc.).

[0045] A pair of external electrodes 16 are respectively arranged at both ends of the component body 11 in the length direction L. Each external electrode 16 covers a pair of end faces 17c of the component body 11. Among the plurality of internal electrode layers in the inner layer portion 12, one of the internal electrode layers adjacent in the thickness direction T is connected to one external electrode 16, and the other is connected to the other external electrode. Each of the pair of external electrodes 16 has an end face 16a in the length direction L.

[0046] The external electrode 16 includes, for example, a laminated film of a sintered metal layer and a plating layer. The sintered metal layer is formed by, for example, sintering a paste of Cu, Ni, Ag, Pd, Ag-Pd alloy, Au, etc. The plating layer includes, for example, a Ni plating layer and a Sn plating layer covering the Ni plating layer.

[0047] The multilayer ceramic capacitor 10 is manufactured by, for example, forming a pair of external electrodes 16 by sintering, plating, etc. after firing the component body 11. In some cases, a portion of the external electrodes 16 is fired simultaneously with the component body 11, and then, for example, a plating layer of the external electrodes 16 is formed subsequently.

[0048] Figure 2 as well as Figure 3 A mounting structure 1 according to a first embodiment is shown in which a multilayer ceramic capacitor 10 is mounted on a substrate 20 . Figure 2 is a top view of the mounting structure 1, Figure 3 yes Figure 2 The mounting structure 1 includes a substrate 20, a pair of lands 30 spaced apart from each other on the substrate 20, solder 40 disposed on each land 30, and a laminated ceramic capacitor 10. The laminated ceramic capacitor 10 is mounted on the substrate 20 by soldering.

[0049] The substrate 20 is formed into a sheet shape by a material including an insulating material such as resin, glass, glass epoxy, paper phenol, ceramic, etc. The surface 20a of the substrate 20 is covered with an insulating film 22 formed of a solder resist except for a rectangular mounting region 20b.

[0050] The wiring 33 is formed on the surface 20a of the substrate 20. The wiring 33 is discontinuous in the mounting area 20b with the partition 21 sandwiched therebetween, and a pair of connection pads 30 are exposed on both sides of the partition 21. The pair of connection pads 30 are portions of the wiring 33 that are not covered by the insulating film 22. The pair of connection pads 30 are portions of the wiring 33 exposed in the mounting area 20b. The pair of connection pads 30 are arranged on the surface 20a of the substrate 20 so as to be spaced apart from each other in the X direction.

[0051] The wiring 33 including the connection pad 30 is formed by forming a film of a highly conductive metal such as Cu or Ag on the surface 20a of the substrate 20. Figure 2 As shown, each of the pair of connection pads 30 is a rectangular shape when viewed from above, and has substantially the same shape and size. Each of the pair of connection pads 30 is arranged in the X direction so that the positions in the Y direction orthogonal to the X direction are the same. Each of the pair of connection pads 30 has an inner edge 31 on the side of the partition 21 and an outer edge 32 on the opposite side of the partition 21 in the X direction. The outer edge 32 is the boundary portion between the insulating film 22 and the connection pad 30. Both the inner edge 31 and the outer edge 32 extend in the Y direction.

[0052] Regarding the multilayer ceramic capacitor 10 mounted on the substrate 20, the length direction L is substantially along the X direction, the width direction W is substantially along the Y direction, and the thickness direction T is substantially along the up-down direction Z orthogonal to the surface 20a of the substrate 20. Thus, one main surface 17a of the component body 11 is substantially parallel to the surface 20a of the substrate 20 and faces each other. Regarding the multilayer ceramic capacitor 10, one external electrode 16 is connected to one connection land 30 via solder 40, and the other external electrode 16 is connected to the other connection land 30 via solder 40. The end surface 16a of each external electrode 16 is almost covered by the solder 40. The multilayer ceramic capacitor 10 is arranged so that the center in the width direction W coincides with the center in the width direction W of each connection land 30.

[0053] like Figure 2 As shown, the end surface 16a of each external electrode 16 is located closer to the inner edge 31 than the outer edge 32 of the land 30. Therefore, each land 30 includes an inner edge 31 overlapping the multilayer ceramic capacitor 10 in the longitudinal direction L and an outer edge 32 not overlapping in the longitudinal direction L.

[0054] like Figure 4 As shown, each of the pair of external electrodes 16 includes: a flat end surface covering portion 16b covering the end surface 17c of the component body 11; and a square tube-shaped bent portion 16c, which is bent and extended from the end surface covering portion 16b toward the component body 11 side which is the inner side of the length direction L, and covers a pair of main surfaces 17a and a pair of side surfaces 17b. The bent portion 16c covering one main surface 17a of the component body 11 facing the substrate 20 is connected to the connection pad 30 via the solder 40.

[0055] Regarding the solder 40, the type is not particularly limited as long as it has properties suitable for each external electrode 16 and each connection pad 30. For example, it can be Sn-Pb solder 40, Sn-Ag-Cu solder 40, Sn-Cu solder 40, Sn-Bi solder 40, etc.

[0056] like Figure 4 As shown, a gap Gap is formed between the connection pad 30 and the bent portion 16c of the external electrode 16 facing the connection pad 30. The gap Gap is an amount corresponding to the thickness of the solder 40 interposed between the connection pad 30 and the bent portion 16c of the external electrode 16. The solder 40 fills the gap Gap between the external electrode 16 and the connection pad 30 without a gap.

[0057] like Figure 2 to Figure 4 As shown, in the mounting structure 1 of the first embodiment, if the width dimension of the connecting plate 30 along the Y direction is set to c, the dimension of the external electrode 16 in the X direction is set to e, and the gap between the connecting plate 30 and the curved portion 16c of the external electrode 16 is set to Gap, then the following formula (1) is satisfied, and preferably, the following formula (2) is satisfied.

[0058] 3.4<(c×e) / Gap<258.8…(1)

[0059] 9.0<(c×e) / Gap<48.2…(2)

[0060] Furthermore, c / e is preferably 0.5 or more and 4 or less.

[0061] In the first embodiment, soldering with the solder 40 can be performed by reflow soldering. That is, the multilayer ceramic capacitor 10 can be mounted on the substrate 20 by reflow soldering. In the case of reflow soldering, since the solder paste material is applied to the connection pad 30 in advance, the configuration area of ​​the solder 40 can be relatively small. For example, the dimension in the width direction W (such as Figure 1 When the distance D1 between the end face 16a of the external electrode 16 and the outer edge 32 of the connecting pad 30 in the in-plane direction of the substrate 20 is 0.8mm, D1 is preferably 0.02mm or more and 0.8mm or less. That is, D1 is preferably a width dimension W / 2~W. In addition, when the external electrode 16 is not formed on a pair of side surfaces 17b, D1 can be further reduced, and when the width dimension W is 0.3mm~0.8mm, it can be set to 0.02mm or more and 0.05mm or less. That is, the width dimension 1.1W is preferred.

[0062] In the mounting structure 1 according to the first embodiment, if stress is applied to the multilayer ceramic capacitor 10 due to deflection of the substrate 20 or the like, the multilayer ceramic capacitor 10 is easily deformed. Figure 4The illustrated example shows that cracks are generated in the component body 11 starting from the edge of the bent portion 16c of the external electrode 16 and the boundary portion 15 of the component body 11. However, in the mounting structure 1 according to the first embodiment, by satisfying the above formula (1), stress is less likely to be applied to the boundary portion 15, and the generation of cracks can be suppressed. By satisfying the above formula (2), stress is even less likely to be applied to the boundary portion 15, and the crack suppression effect can be further significantly obtained.

[0063] The mounting structure 1 involved in the first embodiment described above includes: a pair of connection pads 30, which are arranged on the substrate 20 so as to be separated from each other; solders 40, which are respectively arranged on the connection pads 30; and a laminated ceramic capacitor 10 as an electronic component, which includes a component body 11 having a length direction L and a pair of external electrodes 16 arranged at both ends of the component body 11 in the length direction L, and the pair of external electrodes 16 are respectively connected to the pair of connection pads 30 via the solder 40. When the separation direction of the pair of connection pads 30 is set as the X direction and the direction orthogonal to the X direction is set as the Y direction, if the width dimension of the connection pad 30 along the Y direction is set as c, the dimension of the external electrode 16 in the X direction is set as e, and the gap between the connection pad 30 and the external electrode 16 is set as Gap, the following formula (1) is satisfied.

[0064] 3.4<(c×e) / Gap<258.8…(1)

[0065] This can suppress the occurrence of cracks in the multilayer ceramic capacitor 10 when the substrate 20 is bent.

[0066] In the mounting structure 1 according to the first embodiment, it is preferable that the following formula (2) is satisfied.

[0067] 9.0<(c×e) / Gap<48.2…(2)

[0068] Thereby, the crack suppression effect can be further significantly obtained.

[0069] In the mounting structure 1 involved in the first embodiment, the connecting plate 30 may also include an inner end edge 31 overlapping with the stacked ceramic capacitor 10 in the length direction L and an outer end edge 32 not overlapping in the length direction L, and a distance D1 in the in-plane direction of the substrate 20 between the end face 16a of the external electrode 16 in the length direction L and the outer end edge 32 of the connecting plate 30 is greater than 0.02 mm and less than 0.8 mm.

[0070] Thus, soldering by reflow mounting can be reliably performed, and the size of the land 30 can be suppressed to the minimum necessary size.

[0071] (Second embodiment)

[0072] Next, refer to Figure 5 as well as Figure 6 The second embodiment is described. The second embodiment is an embodiment in which a portion of the first embodiment is modified. Therefore, in the reference drawings, the same components as those of the first embodiment are denoted by the same reference numerals, and their descriptions are omitted, and only the differences are mainly described.

[0073] Figure 5 is a top view of a mounting structure 2 according to a second embodiment. Figure 6 yes Figure 5 VI-VI cross-sectional view. In the mounting structure 2, an adhesive 50 for bonding the component body 11 of the multilayer ceramic capacitor 10 and the substrate 20 is disposed between the pair of lands 30. The adhesive 50 is disposed substantially in the center of the partition 21.

[0074] In addition, solder adhesion inhibitors 60 are disposed on both sides of the adhesive 50 in the X direction. Figure 6 As shown in FIG. 1 , when viewed from the side, the solder adhesion preventing material 60 fills the space surrounded by the multilayer ceramic capacitor 10, the lands 30, the substrate 20, and the adhesive 50. Thus, the end 31a including the inner edge 31 of each land 30 is covered with the solder adhesion preventing material 60 that prevents the solder 40 from being attached to the end 31a. In addition, the above-mentioned boundary portion 15 is covered with the solder adhesion preventing material 60.

[0075] As the adhesive 50, for example, an epoxy resin adhesive or the like can be used. In addition, as the solder adhesion preventing material 60, for example, a solder resist or an adhesive can be used. As the solder resist or adhesive of the solder adhesion preventing material 60, an epoxy resin adhesive can be used. Therefore, the adhesive 50 and the solder adhesion preventing material 60 can be formed into one piece by an epoxy resin adhesive.

[0076] In the second embodiment, welding by the solder 40 can be performed by jet welding by spraying the solder 40. That is, the multilayer ceramic capacitor 10 can be mounted on the substrate 20 by jet welding. In the case of jet welding mounting, the area where the solder 40 is sprayed is preferably set in advance to be larger than that in the case of reflow soldering. Figure 5 As shown, the distance D2 between the end face 16a of the external electrode 16 and the outer edge 32 of the connection pad 30 in the in-plane direction of the substrate 20 is longer than that in the first embodiment, and the dimension in the width direction W (such as Figure 1When the distance between the Sn plating layer on one side and the Sn plating layer on the other side is 0.3 mm, it is 0.3 mm or more and 0.6 mm or less, and when the dimension in the width direction W is 0.8 mm, it is 0.8 mm or more and 1.6 mm or less, and preferably the dimension in the width direction W is twice the size thereof. It is preferably set as such.

[0077] In the mounting structure 2 of the second embodiment, the solder adhesion preventing member 60 is provided at a stage before mounting the multilayer ceramic capacitor 10, and when mounting the multilayer ceramic capacitor 10, the multilayer ceramic capacitor 10 is bonded to the substrate 20 using the adhesive 50. Therefore, the gap Gap becomes an amount corresponding to the thickness of the solder adhesion preventing member 60 existing between the external electrode 16 and the land 30. The adhesive 50 prevents the multilayer ceramic capacitor 10 from falling off the substrate 20, and thus enables mounting by flow soldering.

[0078] In the mounting structure 2 according to the second embodiment, the adhesive 50 for bonding the multilayer ceramic capacitor 10 and the substrate 20 is disposed between the pair of lands 30 .

[0079] According to the second embodiment, after the multilayer ceramic capacitor 10 is bonded to the substrate 20 by the adhesive 50 so as not to fall off the substrate 20, the multilayer ceramic capacitor 10 can be mounted on the substrate 20 by the solder 40. This increases the degree of freedom in the placement posture of the substrate 20 during mounting, and enables easy mounting.

[0080] In the mounting structure 2 involved in the second embodiment, the connecting plate 30 includes an inner end edge 31 overlapping with the stacked ceramic capacitor 10 in the length direction L and an outer end edge 32 not overlapping in the length direction L, and a distance D2 in the in-plane direction of the substrate 20 between the end face 16a of the external electrode 16 in the length direction L and the outer end edge 32 of the connecting plate 30 is greater than 0.3 mm and less than 1.6 mm, and an adhesive 50 for bonding the stacked ceramic capacitor 10 and the substrate 20 is arranged between a pair of connecting plates 30.

[0081] Thus, welding by spray welding can be reliably performed, and the size of the land 30 can be suppressed to the minimum necessary size.

[0082] In the mounting structure 2 according to the second embodiment, the end 31a of the land 30 including the inner edge 31 is preferably covered with a solder adhesion inhibitor 60 for preventing the solder 40 from adhering to the end 31a. As the solder adhesion inhibitor 60, a solder resist or an adhesive can be used.

[0083] Thus, the gap Gap between the land 30 and the external electrode 16 can be ensured by the solder adhesion preventing material 60, and the amount of the gap Gap can be easily adjusted by the thickness of the solder adhesion preventing material 60, resulting in that the bonding strength can be appropriately adjusted based on the thickness of the solder 40. Furthermore, if the boundary portion 15 between the external electrode 16 and the component body 11 is covered by the solder adhesion preventing material 60 so that the solder 40 does not reach the boundary portion 15, the occurrence of cracks in the multilayer ceramic capacitor 10 can be further suppressed.

[0084] In addition, the present invention is not limited to the above-mentioned embodiment, and modifications, improvements, etc. within the scope that can achieve the object of the present invention are included in the present invention.

[0085] For example, in the mounting structure 1 of the first embodiment, the adhesive 50 may be disposed between the multilayer ceramic capacitor 10 and the substrate 20 to bond the multilayer ceramic capacitor 10 and the substrate 20 as in the second embodiment.

[0086] The mounting structure 2 of the second embodiment can also be obtained by using reflow mounting. In this case, it is also possible to set the structure as follows, that is, without using the adhesive 50, only the solder adhesion inhibitor 60 is provided in the stage before mounting. Figure 6 The portion of the adhesive 50 may be set to a hollow state, or the portion of the adhesive 50 may be filled with the solder adhesion inhibitor 60 .

[0087] The multilayer ceramic capacitor 10 in the above embodiment is an example of an electronic component, but the electronic component is not limited thereto, and other two-terminal electronic components such as inductors can also be applied. For example, in the case of an inductor, the component body includes magnetic ceramics or the like.

[0088] [Example]

[0089] Hereinafter, examples of the present invention will be described.

[0090] In the mounting structure having substantially the same structure as the mounting structure 1 shown in the first embodiment, it is assumed that the stress at which the substrate 20 bends and cracks are generated in the component body 11 of the laminated ceramic capacitor 10 is 135 MPa. The value of (c×e) / Gap at the time when the stress causing the substrate 20 to bend reaches 135 MPa is hypothetically calculated. The results are shown in Table 1.

[0091] In addition, if Figure 7As shown, for a substrate 20 on which a multilayer ceramic capacitor 10 is mounted, the substrate 20 is bent by applying pressure to the center between the two ends from above, with the multilayer ceramic capacitor 10 arranged at the bottom and supported at both ends in the length direction L. The amount of downward displacement of the center at this time is defined as the deflection amount (mm). In the embodiment, (c×e) / Gap is obtained when the deflection amounts are 1 mm, 2 mm, 3 mm, and 4 mm, respectively.

[0092] [Table 1]

[0093] Deflection Stress(MPa) (c×e) / Gap 1mm 135 61.06 2mm 135 5.83 3mm 135 3.06 4mm 135 2.24

[0094] like Figure 8 As shown, based on Table 1, the values ​​of (c×e) / Gap when the deflection amounts of the substrate 20 are 1 mm, 2 mm, 3 mm, and 4 mm are plotted. Figure 8 Curve A shows the relationship between the deflection amount and (c×e) / Gap obtained from the plot.

[0095] In order to provide a mounting structure that does not cause cracks in the multilayer ceramic capacitor even when the deflection amount of the substrate is 1 mm or more and 2 mm or less, according to Figure 8 It can be seen that the requirement is "9.0<(c×e) / Gap<48.2". In addition, a larger deflection than this can be allowed, and the deflection of the substrate can also be greater than 0.5 mm and less than 3 mm. In this case, according to Figure 8 It can be seen that the appropriate setting is "3.4<(c×e) / Gap<258.8".

[0096] From these results, it is understood that (c×e) / Gap is preferably 3.4<(c×e) / Gap<258.8, and more preferably 9.0<(c×e) / Gap<48.2.

Claims

1. An electronic component mounting structure comprising: A pair of connection pads are arranged on the substrate to be spaced apart from each other; Solders are respectively disposed on the connection pads; and An electronic component 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 pair of external electrodes are respectively connected to the pair of connection pads via the solder. When the separation direction of the pair of lands is set as the X direction and the direction orthogonal to the X direction is set as the Y direction, If the width of the connection pad along the Y direction is c, the dimension of the external electrode in the X direction is e, and the gap between the connection pad and the external electrode is Gap, the following formula (1) is satisfied: 3.4<(c×e) / Gap<258.8…(1).

2. The electronic component mounting structure according to claim 1, wherein: Satisfies the following formula (2): 9.0<(c×e) / Gap<48.2…(2).

3. The electronic component mounting structure according to claim 1 or 2, wherein: The connection pad includes an inner end edge overlapping with the electronic component in the longitudinal direction and an outer end edge not overlapping with the electronic component in the longitudinal direction. A distance between the end surface of the external electrode in the longitudinal direction and the outer edge of the land in the in-plane direction of the substrate is not less than 0.02 mm and not more than 0.8 mm.

4. The electronic component mounting structure according to claim 1 or 2, wherein: An adhesive for bonding the electronic component and the substrate is arranged between the pair of lands.

5. The electronic component mounting structure according to claim 1 or 2, wherein: The connection pad includes an inner end edge overlapping with the electronic component in the longitudinal direction and an outer end edge not overlapping with the electronic component in the longitudinal direction. The distance between the end surface of the external electrode in the longitudinal direction and the outer edge of the connection pad in the in-plane direction of the substrate is 0.3 mm or more and 1.6 mm or less. An adhesive for bonding the electronic component and the substrate is arranged between the pair of lands.

6. The electronic component mounting structure according to claim 3, wherein: An end portion of the connection land including the inner edge is covered with a solder adhesion inhibitor that prevents the solder from adhering to the end portion.

7. The electronic component mounting structure according to claim 6, wherein: The solder adhesion preventing material is a solder resist.

8. The electronic component mounting structure according to claim 6, wherein: The solder adhesion inhibitor is an adhesive.

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