Electronic component

Abstract

To provide an electronic component capable of suppressing a warp.SOLUTION: An electronic component 1 includes: a function element 2 with an electrode 21; and a bus bar 3 that is electrically and mechanically connected to the electrode 21. The bus bar 3 includes: a body part 30 having a longer direction D1; and a connection conductor 33 that is formed integrally with the body part 30. The connection conductor 33 has: two arm parts 8 that are directly connected to the body part 30; and two connections 6 corresponding one-to-one to the two arm parts 8, which protrude from the tip of the two arm parts 8 and are connected to the electrode 21 via a conductive material 60. Defining the center distance between the body part 30 and the two arm parts 8 as A, and the center distance between two connections 6 as B, and when the linear expansion coefficient of the function element 2 is larger than the linear expansion coefficient of the bus bar 3, A>B is satisfied.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure generally relates to electronic components, and more particularly to an electronic component including a functional element and a bus bar.

Background Art

[0002] Patent Document 1 discloses a capacitor. This capacitor includes a plurality of elements and a pair of bus bars.

[0003] Here, each of the plurality of elements has a flat shape including a pair of flat portions and a pair of curved portions. Each of the plurality of elements has a pair of end face electrodes at both ends thereof. The plurality of elements are arranged in a row such that the pair of flat portions are located on the same plane or parallel planes, respectively.

[0004] On the other hand, each of the pair of bus bars has an electrode connection portion connected to each end face electrode of the plurality of elements and an external connection portion for electrically connecting the plurality of elements to the outside. The pair of bus bars are arranged along the arrangement direction of the plurality of elements.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] However, in the capacitor of Patent Document 1, when a thermal load is applied, there is a problem that warping easily occurs with respect to the arrangement direction of the plurality of elements.

[0007] An object of the present disclosure is to provide an electronic component capable of suppressing warping.

Means for Solving the Problems

[0008] An electronic component according to an aspect of the present disclosure includes a functional element having electrodes and a bus bar electrically and mechanically connected to the electrodes. The bus bar includes a main body portion having a longitudinal direction and a connection conductor integrally formed with the main body portion. The connection conductor has two arm portions directly connected to the main body portion, and two connection portions that correspond one-to-one with the two arm portions, protrude from the tips of the two arm portions, and are connected to the electrodes by conductive members. When the center-to-center distance between the connection points of the main body portion and the two arm portions is A and the center-to-center distance between the two connection portions is B, when the coefficient of linear expansion of the functional element is larger than the coefficient of linear expansion of the bus bar, A > B holds.

Advantages of the Invention

[0009] According to the present disclosure, warping can be suppressed.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

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Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Embodiments for Carrying Out the Invention

[0011] 1. Overview Examples of a general electronic component 1 are shown in Figs. 9A and 9B. This electronic component 1 includes a functional element 2 and a bus bar 3. The functional element 2 has electrodes 21. The bus bar 3 is electrically and mechanically connected to the electrodes 21.

[0012] More specifically, the bus bar 3 has a main body part 30 and a plurality of connection parts 6. The main body part 30 has a longitudinal direction D1. The plurality of connection parts 6 are directly formed on the main body part 30 and extend in a direction D2 orthogonal to the longitudinal direction D1. And two connection parts 6 are electrically and mechanically connected to one functional element 2. Note that the capacitor of Patent Document 1 also has a similar structure.

[0013] Here, when a thermal load is applied to the above-described electronic component 1, as shown in FIG. 9B, warping is likely to occur with respect to the arrangement direction (longitudinal direction D1) of the plurality of functional elements 2. In order to suppress this warping, when the inventors conducted investigations and research, it was found that the difference in the thermal physical properties (for example, the coefficient of linear expansion) between the functional element 2 and the bus bar 3 is one of the causes of the above warping. Furthermore, as a result of continuing the investigation and research, it was found that a large stress is likely to occur at the portion where the connection portion 6 and the main body portion 30 are connected (portion R in FIG. 9A).

[0014] Based on the above, the inventors presume the mechanism of warping generation in the electronic component 1 as follows. That is, when a thermal load is applied to the electronic component 1 (including the case where the functional element 2 itself generates heat due to energization), due to the difference in the degree of thermal expansion of the functional element 2 (indicated by the double arrow f2 in FIG. 9A) and the degree of thermal expansion of the bus bar 3 (indicated by the double arrow f3 in FIG. 9A), warping (indicated by the double arrow w2 in FIG. 9A) occurs in the functional element 2. In the electronic component 1 shown in FIGS. 9A and 9B, since the plurality of functional elements 2 are arranged in the longitudinal direction D1, the warping generated in each of the plurality of functional elements 2 accumulates, and as a whole, the electronic component 1 warps in a bow shape as shown by the double arrow w1 in FIG. 9A. Note that δ1 in FIG. 9B indicates the amount of deformation of the warping generated in the electronic component 1.

[0015] Based on the above presumption mechanism, the inventors further continued their intensive research, and as a result, developed an electronic component 1 capable of suppressing warping.

[0016] That is, in the electronic component 1 according to the present embodiment, the bus bar 3 includes a connection conductor 33 (see FIGS. 1 and 10A). The connection conductor 33 is integrally formed with the main body portion 30. Further, the connection conductor 33 has two arm portions 8 and two connection portions 6. The two arm portions 8 are directly connected to the main body portion 30. The two connection portions 6 correspond one-to-one to the two arm portions 8. The two connection portions 6 protrude from the tips of the two arm portions 8. The two connection portions 6 are connected to the electrodes 21 by conductive members 60 (see FIG. 2).

[0017] Then, as shown in FIGS. 6 and 10B, when the center-to-center distance between the connection points of the main body 30 and the two arms 8 is A and the center-to-center distance between the two connection parts 6 is B, if the linear expansion coefficient of the functional element 2 is larger than that of the bus bar 3, A > B holds.

[0018] The electronic component 1 shown in FIGS. 9A and 9B and the electronic component 1 according to the present embodiment are common in that two connection parts 6 are electrically and mechanically connected to one functional element 2. In this way, by electrically and mechanically connecting two connection parts 6 instead of one connection part 6 to one functional element 2, any of the above electronic components 1 can conduct a high current and ensure the required current capacity.

[0019] On the other hand, the electronic component 1 shown in FIGS. 9A and 9B and the electronic component 1 according to the present embodiment differ in the following points. That is, in the electronic component 1 shown in FIGS. 9A and 9B, the center-to-center distance between the bases of the two connection parts 6 is equal to the center-to-center distance between the tips of the two connection parts 6. In contrast, in the electronic component 1 according to the present embodiment, the center-to-center distance A between the bases of the two arms 8 is larger than the center-to-center distance B between the tips of the two connection parts 6. Therefore, even if stress is generated near the bases of the two arms 8 (the R part in FIG. 1), it is easier to relieve the stress.

[0020] Therefore, according to the electronic component 1 according to the present embodiment, warping can be suppressed.

[0021] 2. Details Hereinafter, the electronic component 1 according to the present embodiment will be described with reference to FIGS. 1 to 9B. Each figure is a schematic diagram, and the ratio of the size and thickness of each component in each figure does not necessarily reflect the actual dimensional ratio.

[0022] The arrows indicating the respective directions in the figures are not intended to define the direction during the use of the electronic component 1, but are merely shown for easier understanding of the description and have no physical entity. The first direction D1, the second direction D2, and the third direction D3 are mutually orthogonal. The first direction D1 is the longitudinal direction of the main body 30 of the bus bar 3 and may be referred to as the "left - right direction". One side of the first direction D1 means "left", and the other side means "right". The second direction D2 is the thickness direction (minor - axis direction) of the functional element 2 and may be referred to as the "up - down direction". One side of the second direction D2 means "up", and the other side means "down". The third direction D3 is the direction connecting the two electrodes 21 of the functional element 2 and may be referred to as the "front - back direction". One side of the third direction D3 means "front", and the other side means "back". Viewing along the first direction D1 is called a side view. Viewing along the second direction D2 is called a plan view. Viewing along the third direction D3 is called a front view.

[0023] Figures 1 to 4 show the electronic component 1 according to this embodiment. The electronic component 1 includes a plurality (four in this embodiment) of functional elements 2 and a plurality (two in this embodiment) of bus bars 3. As shown in FIGS. 3 and 4, the four functional elements 2 are arranged in the left - right direction, and the two bus bars 3 are arranged in the front - back direction.

[0024] <Functional element> The functional element 2 is not particularly limited, and examples include passive elements, active elements, etc. In this embodiment, the functional element 2 is a film capacitor element 27.

[0025] As shown in FIG. 5, the functional element 2 has an element body 20 and two electrodes 21.

[0026] ≪Element body≫ The element body 20 has a shape of a rounded rectangle when viewed from the front and extends in the front-rear direction. The element body 20 has two end faces 22 and an outer peripheral face 23. The two end faces 22 are the first end face 221 and the second end face 222. The first end face 221 is the face facing forward, and the second end face 222 is the face facing backward. The outer peripheral face 23 connects the first end face 221 and the second end face 222. Specifically, the outer peripheral face 23 connects the outer peripheral edge of the first end face 221 and the outer peripheral edge of the second end face 222.

[0027] The element body 20 is formed by winding two metallized films 24. Specifically, by winding the two metallized films 24 around an axis parallel to the front-rear direction to form a cylindrical shape, and then pressing in the up-down direction to flatten it, the element body 20 is obtained. Thereby, the element body 20 has a major axis parallel to the left-right direction and a minor axis parallel to the up-down direction. The two metallized films 24 are the first metallized film 241 and the second metallized film 242.

[0028] The metallized film 24 has a dielectric film 25 and a metal layer 26.

[0029] The dielectric film 25 has a predetermined thickness and is in a long strip shape having a predetermined width in the front-rear direction. The thickness of the dielectric film 25 is not particularly limited, but for example, it is 1 μm or more and 10 μm or less. The material of the dielectric film 25 is not particularly limited, but for example, polypropylene (PP), polyethylene terephthalate (PET), etc. may be mentioned. The dielectric film 25 of the first metallized film 241 is the first dielectric film 251, and the dielectric film 25 of the second metallized film 242 is the second dielectric film 252.

[0030] The metal layer 26 is provided on the dielectric film 25. Specifically, the metal layer 26 is formed on one side of the dielectric film 25 by vapor deposition or the like. The material of the metal layer 26 is not particularly limited, and examples thereof include aluminum (Al), magnesium (Mg), and alloys thereof. The thickness of the metal layer 26 is not particularly limited, and is, for example, 5 nm or more and 100 nm or less. Note that the metal layer 26 of the first metallization film 241 is the first metal layer 261, and the metal layer 26 of the second metallization film 242 is the second metal layer 262. Inside the element body 20, the first metal layer 261 and the second metal layer 262 face each other with the dielectric film 25 interposed therebetween.

[0031] <<Electrode>> The two electrodes 21 are formed on the two end faces 22 of the element body 20 by metal spraying or the like. Specifically, the two electrodes 21 are the first electrode 211 and the second electrode 212. The first electrode 211 is formed on the first end face 221 of the element body 20, and the second electrode 212 is formed on the second end face 222 of the element body 20. The material of the electrode 21 is not particularly limited, and examples thereof include zinc (Zn), tin (Sn), and alloys thereof. The thickness of the electrode 21 is not particularly limited, and is, for example, 0.5 mm or more and 1.5 mm or less.

[0032] The electrode 21 is electrically connected to the metal layer 26 inside the element body 20. Specifically, since the front edge of the first metal layer 261 is exposed at the first end face 221 of the element body 20, the first electrode 211 is connected to the first metal layer 261. Note that the rear edge of the first metal layer 261 is not exposed at the second end face 222 of the element body 20, so the first metal layer 261 is not connected to the second electrode 212. On the other hand, since the rear edge of the second metal layer 262 is exposed at the second end face 222 of the element body 20, the second electrode 212 is connected to the second metal layer 262. Note that the front edge of the second metal layer 262 is not exposed at the first end face 221 of the element body 20, so the second metal layer 262 is not connected to the first electrode 211.

[0033] <<Coefficient of linear expansion>> The linear expansion coefficient of the functional element 2 is preferably 4.2×10 -5 / K or more and 1.7×10 -4 / K or less. In particular, the linear expansion coefficient in the left - right direction is preferably within the above numerical range. Also, the linear expansion coefficient in the temperature range from normal temperature (for example, 25°C) to 100°C is preferably within the above numerical range. The linear expansion coefficient of the functional element 2 can be measured, for example, by the compression - expansion method of thermomechanical analysis (TMA).

[0034] <Bus bar> The bus bar 3 is a conductive member interposed between the functional element 2 and an external device (not shown) and used to electrically connect the functional element 2 and the external device. The bus bar 3 is formed by cutting out a metal plate into a predetermined shape and appropriately bending it. The metal plate is not particularly limited, and examples include a copper plate and an aluminum plate.

[0035] In this embodiment, the two bus bars 3 are the first bus bar 31 and the second bus bar 32. When simply referring to the bus bar 3 below, each of the first bus bar 31 and the second bus bar 32 is meant.

[0036] In the electronic component 1, the bus bar 3 is electrically and mechanically connected to the electrode 21. The bus bar 3 includes a main body portion 30, a plurality (four in this embodiment) of connection conductors 33, and an external connection terminal 34.

[0037] ≪Main body portion≫ The main body portion 30 has a longitudinal direction D1. That is, the main body portion 30 is a portion extending in the left - right direction. The main body portion 30 may be either in contact or non - contact with the electrode 21, but is not directly fixed to the electrode 21.

[0038] ≪Connection conductor≫ The connection conductor 33 is integrally formed with the main body portion 30. In this embodiment, the connection conductor 33 is formed below the main body portion 30.

[0039] As shown in FIGS. 3 and 4, a plurality (four in this embodiment) of connection conductors 33 are connected one-to-one with a plurality (four in this embodiment) of functional elements 2. In this way, one bus bar 3 is connected with a plurality of functional elements 2.

[0040] One connection conductor 33 has two arm portions 8 and two connection portions 6.

[0041] 〔Arm Portion〕 The two arm portions 8 are directly connected to the main body portion 30. The two arm portions 8 are the first arm portion 81 and the second arm portion 82.

[0042] The first arm portion 81 is linear with a predetermined width and is inclined with respect to the left-right direction. Specifically, the first arm portion 81 extends downward as it goes toward the right side.

[0043] On the other hand, the second arm portion 82 is symmetrical to the first arm portion 81 with respect to the left and right. That is, the second arm portion 82 is also linear with a predetermined width and is inclined with respect to the left-right direction. However, the second arm portion 82 extends downward as it goes toward the left side.

[0044] In this way, the center-to-center distance in the left-right direction between the first arm portion 81 and the second arm portion 82 becomes shorter from top to bottom. The above center-to-center distance is the distance connecting the center of the width dimension of the first arm portion 81 in the direction orthogonal to the extending direction of the first arm portion 81 and the center of the width dimension of the second arm portion 82 in the direction orthogonal to the extending direction of the second arm portion 82.

[0045] Note that the two arm portions 8 may be either in contact or non-contact with the electrode 21, but are not directly fixed to the electrode 21.

[0046] 〔Connection Portion〕 The two connection portions 6 correspond one-to-one to the two arm portions 8. Specifically, the two connection portions 6 are the first connection portion 61 and the second connection portion 62. The first connection portion 61 corresponds to the first arm portion 81, and the second connection portion 62 corresponds to the second arm portion 82.

[0047] The two connecting portions 6 project from the tips of the two arm portions 8. Specifically, the first connecting portion 61 projects downward from the tip of the first arm portion 81, and the second connecting portion 62 projects downward from the tip of the second arm portion 82.

[0048] As shown in FIG. 2, the two connecting portions 6 are connected to the electrode 21 by a conductive member 60. Specifically, the connecting portion 6 is overlapped on the electrode 21, and the conductive member 60 is supplied from above, and the electrode 21 and the connecting portion 6 are connected by this conductive member 60. The conductive member 60 is not particularly limited, and examples thereof include solder.

[0049] In the above manner, the bus bar 3 is electrically and mechanically connected to the electrode 21.

[0050] ≪External connection terminal≫ The external connection terminal 34 is a terminal used to connect the electronic component 1 to an external device (not shown). The external connection terminal 34 is integrally formed with the main body portion 30. In the present embodiment, the external connection terminal 34 projects forward in both the first bus bar 31 and the second bus bar 32. However, an insulating plate 93 is interposed between the external connection terminal 34 of the first bus bar 31 and the external connection terminal 34 of the second bus bar 32, and the two external connection terminals 34 are electrically insulated from each other.

[0051] ≪Coefficient of linear expansion≫ The coefficient of linear expansion of the bus bar 3 is preferably 8.5×10 -6 / K or more and 3.4×10 -5 / K or less. In particular, it is preferable that the coefficient of linear expansion in the left-right direction is within the above numerical range. Also, it is preferable that the coefficient of linear expansion in the temperature range from normal temperature (for example, 25°C) to 100°C is within the above numerical range. The coefficient of linear expansion of the bus bar 3 can be measured, for example, by the compression / dilatation method of thermomechanical analysis (TMA).

[0052] ≪Relational expression≫ Next, with reference to FIG. 6, the relational expressions that hold for the connection conductor 33 of the present embodiment will be described.

[0053] That is, in the present embodiment, when the center - to - center distance between the connection points of the main body 30 and the two arm portions 8 is A, and the center - to - center distance between the two connection portions 6 is B, when the coefficient of linear expansion of the functional element 2 is greater than the coefficient of linear expansion of the bus bar 3, A > B holds.

[0054] More specifically, the above - mentioned A is the distance connecting the center of the width dimension of the first arm portion 81 at the connection point (the base of the first arm portion 81) between the main body 30 and the first arm portion 81 and the center of the width dimension of the second arm portion 82 at the connection point (the base of the second arm portion 82) between the main body 30 and the second arm portion 82. On the other hand, the above - mentioned B is the distance connecting the center of the width dimension of the first connection portion 61 in the direction orthogonal to the extending direction of the first connection portion 61 (the left - right direction) and the center of the width dimension of the second connection portion 62 in the direction orthogonal to the extending direction of the second connection portion 62 (the left - right direction).

[0055] Also, in the present embodiment, preferably, 2.9 ≤ A / B ≤ 8.3 holds.

[0056] Furthermore, in the present embodiment, when the line segment connecting the connection points of the main body 30 and the two arm portions 8 is defined as line segment C, for the angle θ [deg] formed by the line segment C and the direction E in which at least one of the two arm portions 8 extends, 26.5 ≤ θ ≤ 60 holds.

[0057] More specifically, the line segment C connects the center of the width dimension of the first arm portion 81 at the connection point (the base of the first arm portion 81) between the main body portion 30 and the first arm portion 81 and the center of the width dimension of the second arm portion 82 at the connection point (the base of the second arm portion 82) between the main body portion 30 and the second arm portion 82. The above-mentioned E is the direction E1 in which the first arm portion 81 extends and / or the direction E2 in which the second arm portion 82 extends. The above-mentioned angle θ is the angle θ1 formed by the line segment C and the direction E1 in which the first arm portion 81 extends and / or the angle θ2 formed by the line segment C and the direction E2 in which the second arm portion 82 extends. In the present embodiment, since the first arm portion 81 and the second arm portion 82 are symmetric about the left and right, the magnitudes of the angle θ1 and the angle θ2 are the same.

[0058] <Function and Effect> In the electronic component 1 according to the present embodiment, the linear expansion coefficient of the functional element 2 is larger than the linear expansion coefficient of the bus bar 3. Therefore, before applying a thermal load to the electronic component 1, even if the distance between two points on the electrode 21 of the functional element 2 is equal to the distance between two points on the main body portion 30 of the bus bar 3, after applying a thermal load to the electronic component 1, the distance between two points on the electrode 21 of the functional element 2 is larger than the distance between two points on the main body portion 30 of the bus bar 3.

[0059] Therefore, in the electronic component 1 according to the present embodiment, the center-to-center distance A between the bases of the two arm portions 8 is made larger than the center-to-center distance B between the tips of the two connection portions 6. Here, the bases of the two arm portions 8 are easily affected by the thermal properties of the bus bar 3, and the tips of the two connection portions 6 are easily affected by the thermal properties of the functional element 2. Therefore, when a thermal load is applied to the electronic component 1, although both A and B increase due to thermal expansion, the difference between them becomes smaller. As a result, the stress generated near the bases of the two arm portions 8 (the R portion in FIG. 1) becomes smaller.

[0060] For the above reasons, according to the present embodiment, the warping of the electronic component 1 can be reduced. Thereby, the connection reliability between the functional element 2 and the bus bar 3 and the dimensional accuracy of the electronic component 1 can also be improved.

[0061] Also, in the electronic component 1 according to the present embodiment, it is preferable that 2.9 ≦ A / B ≦ 8.3 holds. Thereby, the warpage of the electronic component 1 can be further suppressed (for details, refer to the section of "Examples").

[0062] Also, in the electronic component 1 according to the present embodiment, as shown in FIG. 6, regarding the angle θ [deg] formed by the line segment C and the direction E in which the arm portion 8 extends, it is preferable that 26.5 ≦ θ ≦ 60 holds. Thereby, the warpage of the electronic component 1 can be further suppressed (for details, refer to the section of "Examples").

[0063] Also, in the electronic component 1 according to the present embodiment, the functional element 2 is a film capacitor element 27. The film capacitor element 27 uses a plastic film as a dielectric and has a large expansion and contraction due to heat. However, in the electronic component 1 according to the present embodiment, since the bus bar 3 in which the Y-shaped connection conductor 33 is connected to the main body portion 30 via the connection portion 5 is adopted, it has high utility value even when the functional element 2 is a film capacitor element 27. When the functional element 2 is a film capacitor element 27, the electronic component 1 according to the present embodiment is used, for example, as a component of an inverter of a hybrid vehicle (HEV).

[0064] Also, in the electronic component 1 according to the present embodiment, the linear expansion coefficient of the functional element 2 is -5 4.2 × 10 -4 / K or more and 1.7 × 10

[0065] / K or less. Thereby, the warpage of the electronic component 1 can be further suppressed (for details, refer to the section of "Examples"). -6 Also, in the electronic component 1 according to the present embodiment, the linear expansion coefficient of the bus bar 3 is -5 8.5 × 10

[0066] In addition, although the electronic component 1 according to the present embodiment includes a plurality of functional elements 2, even when only one functional element 2 is provided, warpage can be suppressed.

[0067] <First Modified Example> Next, the electronic component 1 according to the first modified example of the present embodiment will be described with reference to FIGS. 7A to 8B. In this modified example, components similar to those of the present embodiment may be denoted by the same reference numerals as those of the present embodiment, and detailed description thereof may be omitted.

[0068] In this modified example, the electronic component 1 is different from the present embodiment in that it includes a sealing body 9. Further, in this modified example, although the bus bar 3 includes a connection conductor 33 similar to that of the present embodiment (see FIGS. 8A and 8B), it is different from the present embodiment in that the external connection terminal 34 is formed to protrude upward.

[0069] The sealing body 9 includes a case 90 and a filling resin 91.

[0070] The case 90 is open upward. Inside the case 90, a plurality (four in this modified example) of functional elements 2 and a plurality (two in this modified example) of bus bars 3 shown in FIGS. 8A and 8B are accommodated.

[0071] The case 90 has a mounting portion 92. The mounting portion 92 is a portion used to attach the case 90 to an external device. In this modified example, the mounting portions 92 are formed on both the left and right sides of the case 90.

[0072] The filling resin 91 is a resin filled inside the case 90. The filling resin 91 is not particularly limited, and examples thereof include thermosetting resins such as epoxy resins.

[0073] Thus, the sealing body 9 seals at least a part of the bus bar 3 (the part excluding the external connection terminal 34 in this modified example) and the functional element 2. The external connection terminal 34 is exposed to the outside.

[0074] <Operation and Effect of the First Modified Example> In this modification example, when at least a part of the bus bar 3 and the functional element 2 are encapsulated by the encapsulation body 9, a thermal load may be applied to the bus bar 3 and the functional element 2. However, also in this modification example, since A > B holds, for example, warping can be suppressed until the filling resin 91 cures through the gel state from the liquid state. Moreover, since the functional element 2 and the bus bar 3 can be encapsulated in a state where warping is suppressed, both the residual stress and the strain can be reduced.

[0075] <Second Modification Example> Next, the electronic component 1 according to the second modification example of the present embodiment will be described with reference to FIGS. 10A and 10B. In this modification example, the same components as those in the present embodiment may be denoted by the same reference numerals as in the present embodiment, and detailed description thereof may be omitted.

[0076] In this modification example, the shape of the connection conductor 33 is different from the shape of the connection conductor 33 in the present embodiment.

[0077] <<Connection Conductor>> In this modification example, the two arm portions 8 are bent. The first arm portion 81 is bent in an L shape. Specifically, the first arm portion 81 extends downward from the main body portion 30 and then extends to the right. The first connection portion 61 projects downward from the tip of the first arm portion 81.

[0078] On the other hand, the second arm portion 82 is symmetrical to the first arm portion 81 with respect to left and right. That is, the second arm portion 82 is bent in an inverted L shape. Specifically, the second arm portion 82 extends downward from the main body portion 30 and then extends to the left. The second connection portion 62 projects downward from the tip of the second arm portion 82.

[0079] Also in this modification example, in the same manner as in the present embodiment, when the center-to-center distance between the connection points of the main body portion 30 and the two arm portions 8 is defined as A, and the center-to-center distance between the two connection portions 6 is defined as B, when the coefficient of linear expansion of the functional element 2 is larger than the coefficient of linear expansion of the bus bar 3, A > B holds.

[0080] <Operational Effects of the Second Modification Example> Also in this modification, as shown in FIG. 10B, the center - to - center distance A between the bases of the two arm portions 8 is made larger than the center - to - center distance B between the tips of the two connecting portions 6. Therefore, also in this modification, the warpage of the electronic component 1 can be reduced. As a result, the connection reliability between the functional element 2 and the bus bar 3 and the dimensional accuracy of the electronic component 1 can also be improved.

[0081] 3. Other Modifications In this embodiment, the number of functional elements 2 provided in the electronic component 1 is plural, but the number of functional elements 2 provided in the electronic component 1 may be one.

[0082] In this embodiment, the functional element 2 is a film capacitor element 27, but it is not limited thereto. The functional element 2 may be, for example, a power choke coil or the like.

[0083] In this embodiment, the film capacitor element 27 is of a wound type, but a multilayer type may also be used. In the case of the multilayer type, a plurality of metallized films 24 are laminated in one direction (for example, the vertical direction).

[0084] In this embodiment, the number of connection conductors 33 included in the bus bar 3 is plural, but the number of connection conductors 33 included in the bus bar 3 may be one.

[0085] 4. Aspects As is clear from the above - described embodiments and modifications, the present disclosure includes the following aspects. Hereinafter, for the sole purpose of clarifying the correspondence with the embodiments, reference numerals are attached in parentheses.

[0086] The first aspect is an electronic component (1), comprising a functional element (2) having an electrode (21), and a bus bar (3) electrically and mechanically connected to the electrode (21). The bus bar (3) includes a main body portion (30) having a longitudinal direction (D1), and a connection conductor (33) integrally formed with the main body portion (30). The connection conductor (33) has two arm portions (8) directly connected to the main body portion (30), and two connection portions (6) corresponding one-to-one to the two arm portions (8), protruding from the tips of the two arm portions (8) and connected to the electrode (21) by a conductive member (60). When the center-to-center distance between the connection points of the main body portion (30) and the two arm portions (8) is A, and the center-to-center distance between the two connection portions (6) is B, when the coefficient of linear expansion of the functional element (2) is greater than the coefficient of linear expansion of the bus bar (3), A > B holds.

[0087] According to this aspect, warping can be suppressed.

[0088] The second aspect is an electronic component (1) based on the first aspect. In the second aspect, 2.9 ≤ A / B ≤ 8.3 holds.

[0089] According to this aspect, warping can be further suppressed.

[0090] The third aspect is an electronic component (1) based on the first or second aspect. In the third aspect, when the line segment connecting the connection points of the main body portion (30) and the two arm portions (8) is defined as line segment C, for the angle θ [deg] formed by the line segment C and the direction (E) in which at least one of the two arm portions (8) extends, 26.5 ≤ θ ≤ 60 holds.

[0091] According to this aspect, warping can be further suppressed.

[0092] The fourth aspect is an electronic component (1) based on any one of the first to third aspects. In the fourth aspect, it further includes a sealing body (9) that seals at least a part of the bus bar (3) and the functional element (2).

[0093] According to this aspect, warping can be further suppressed.

[0094] The fifth aspect is the electronic component (1) based on any one of the first to fourth aspects. In the fifth aspect, the functional element (2) is a film capacitor element (27) formed by winding or laminating a metallized film (24). The metallized film (24) has a dielectric film (25) and a metal layer (26) provided on the dielectric film (25) and electrically connected to the electrode (21).

[0095] According to this aspect, warping can be further suppressed.

[0096] The sixth aspect is the electronic component (1) based on any one of the first to fifth aspects. In the sixth aspect, the linear expansion coefficient of the functional element (2) is 4.2×10 -5 / K or more and 1.7×10 -4 / K or less.

[0097] According to this aspect, warping can be further suppressed.

[0098] The seventh aspect is the electronic component (1) based on any one of the first to sixth aspects. In the seventh aspect, the linear expansion coefficient of the bus bar (3) is 8.5×10 -6 / K or more and 3.4×10 -5 / K or less.

[0099] According to this aspect, warping can be further suppressed.

[0100] The eighth aspect is the electronic component (1) based on any one of the first to seventh aspects. In the eighth aspect, a plurality of the functional elements (2) are provided. The bus bar (3) includes a plurality of the connection conductors (33). The plurality of functional elements (2) and the plurality of connection conductors (33) are connected one-to-one.

[0101] According to this aspect, warping can be further suppressed.

Example

[0102] Hereinafter, the present disclosure will be specifically described by way of examples. However, the present disclosure is not limited to the following examples.

[0103] <Examples 1 to 8 (e1 to e8)> For each of Examples 1 to 8 (e1 to e8), three types (24 types in total) of analysis models of the electronic component 1 shown in FIG. 3 were created. These 24 types differ in the combination of the center-to-center distance B between the two connection parts 6, the linear expansion coefficient of the functional element 2, and the linear expansion coefficient of the bus bar 3 (see Tables 4 and 5). An example of the size of the electronic component 1 is 60 mm in overall length (longitudinal direction), 40 mm in overall width (depth direction = electrode direction), and 30 mm in overall height (lateral direction).

[0104] That is, as shown in Table 4, the three types of e1(a), e1(b), and e1(c) in Example 1 have a constant center-to-center distance B between the two connection parts 6, a constant linear expansion coefficient of the bus bar 3, and the linear expansion coefficient of the functional element 2 is changed. The same applies to Examples 2 to 4 (e2 to e4).

[0105] On the other hand, as shown in Table 5, the three types of e5(d), e5(e), and e5(f) in Example 5 have a constant center-to-center distance B between the two connection parts 6, a constant linear expansion coefficient of the functional element 2, and the linear expansion coefficient of the bus bar 3 is changed. The same applies to Examples 6 to 8 (e6 to e8).

[0106] <Comparative Examples 1 and 2 (c1, c2)> For each of Comparative Examples 1 and 2 (c1, c2), three types (6 types in total) of analysis models of the electronic component 1 shown in FIG. 9B were created. Note that the electronic component 1 of Comparative Examples 1 and 2 (c1, c2) is the same as the electronic component 1 of Examples 1 to 8 (e1 to e8), except that instead of the connection conductor 33 of the electronic component 1 of Examples 1 to 8 (e1 to e8), the two connection parts 6 protrude directly downward from the main body part 30 of the bus bar 3.

[0107] As shown in Table 4, the three types of c1(a), c1(b), and c1(c) in Comparative Example 1 have a constant center - to - center distance B between the two connecting portions 6, and further, with a constant coefficient of linear expansion of the bus bar 3, the coefficient of linear expansion of the functional element 2 is changed.

[0108] On the other hand, as shown in Table 5, the three types of c2(d), c2(e), and c2(f) in Comparative Example 2 have a constant center - to - center distance B between the two connecting portions 6, and further, with a constant coefficient of linear expansion of the functional element 2, the coefficient of linear expansion of the bus bar 3 is changed.

[0109] <Evaluation> Using the analysis models of the electronic component 1 of Examples 1 - 4 (e1 - e4) and Comparative Example 1 (c1), CAE (Computer Aided Engineering) analysis was performed to measure the warpage deformation amount of each electronic component 1. Under the conditions of CAE analysis, the ambient temperature was raised from 25°C to 85°C. The results are shown in Table 1. Figure 11A is a graph of Table 1.

[0110]

Table 1

[0111] Here, the warpage deformation amount means the deformation amount (δ1) of the warpage of the electronic component 1 with respect to the arrangement direction (the first direction D1) of the plurality of functional elements 2, as shown in Figure 9B.

[0112] From Table 1 and Figure 11A, it can be seen that the smaller the coefficient of linear expansion of the functional element 2, the smaller the warpage deformation amount. Also, if the coefficient of linear expansion of the functional element 2 is the same, it can be seen that the shorter the center - to - center distance B between the two connecting portions 6, the smaller the warpage deformation amount.

[0113] On the other hand, using the analysis models of the electronic component 1 of Examples 5 - 8 (e5 - e8) and Comparative Example 2 (c2), CAE analysis was performed under the same conditions as above to measure the warpage deformation amount of each electronic component 1. The results are shown in Table 2. Figure 11B is a graph of Table 2.

[0114]

Table 2

[0115] From Table 2 and FIG. 11B, it can be seen that if the linear expansion coefficients of the bus bar 3 are the same, the smaller the center - to - center distance B between the two connection parts 6, the smaller the warpage deformation amount.

[0116] Next, for Examples 1 - 4 (specifically, e1(b), e2(b), e3(b) and e4(b)), the stress at the root of the arm part (the stress generated at the connection part between the main body part and the arm part) was measured. The results are shown in FIG. 12A. Note that Examples 5 - 8 (specifically, e5(b), e6(b), e7(b) and e8(b)) also have the same results.

[0117] From FIG. 12A, it can be seen that the smaller the center - to - center distance B between the two connection parts 6, the smaller the stress at the root of the arm part 8.

[0118] Next, Table 3 is shown. Table 3 summarizes the center - to - center distance B between the two connection parts 6, the warpage deformation amount, and the warpage improvement rate for Comparative Example 1 (specifically, c1(b)) and Examples 1 - 4 (specifically, e1(b), e2(b), e3(b) and e4(b)). FIG. 12B is a graph of Table 3. Note that Comparative Example 2 (specifically, c2(e)) and Examples 5 - 8 (specifically, e5(b), e6(b), e7(b) and e8(b)) also have the same results.

[0119]

Table 3

[0120] Here, the warpage improvement rate (%) was calculated by the following formula (1).

[0121]

Equation

[0122] From Table 3 and FIG. 12B, it can be seen that the smaller the center - to - center distance B between the two connecting portions 6, the smaller the warping deformation amount. Also, it can be seen that the smaller the center - to - center distance B between the two connecting portions 6, the larger the warping improvement rate.

[0123] Next, Table 4 is shown. Table 4 summarizes, for Comparative Example 1 (specifically c1(b)) and Examples 1 - 4 (specifically e1(b), e2(b), e3(b) and e4(b)), the ratio (A / B) of the center - to - center distance A between the connection points of the main body portion 30 and the two arm portions 8 to the center - to - center distance B between the two connecting portions 6, and the warping deformation amount. FIG. 13A is a graph of Table 4. Note that Comparative Example 2 (specifically c2(e)) and Examples 5 - 8 (specifically e5(b), e6(b), e7(b) and e8(b)) also yield the same results.

[0124]

Table 4

[0125] From Table 4 and FIG. 13A, it can be seen that the smaller the A / B, the smaller the warping deformation amount.

[0126] Next, Table 5 is shown. Table 5 summarizes, for Comparative Example 1 (specifically c1(b)) and Examples 1 - 4 (specifically e1(b), e2(b), e3(b) and e4(b)), the angle θ formed by the line segment C connecting the connection points of the main body portion 30 and the two arm portions 8 and the direction E in which the arm portion 8 extends, and the warping deformation amount. FIG. 13B is a graph of Table 5. Note that Comparative Example 2 (specifically c2(e)) and Examples 5 - 8 (specifically e5(b), e6(b), e7(b) and e8(b)) also yield the same results.

[0127]

Table 5

[0128] From Table 5 and FIG. 13B, it can be seen that the smaller the angle θ of the arm portion 8, the smaller the warping deformation amount.

Explanation of Reference Numerals

[0129] 1 Electronic component 2 Functional element 21 Electrode 24 Metallized film 25 Dielectric film 26 Metal layer 3 Bus bar 30 Body part 33 Connecting conductor 6 Connection part 60 Conductive member 8 Arm part 9 Sealing body D1 First direction (longitudinal direction) E Direction in which the arm part extends

Claims

1. A functional element having an electrode, and a bus bar electrically and mechanically connected to the electrode, The bus bar includes a main body portion having a longitudinal direction, and a connection conductor integrally formed with the main body portion, The connection conductor has two arm portions directly connected to the main body portion, and two connection portions corresponding one-to-one to the two arm portions, protruding from the tips of the two arm portions, and connected to the electrode by a conductive member, When the center-to-center distance between the connection points of the main body portion and the two arm portions is A, and the center-to-center distance between the two connection portions is B, when the coefficient of linear expansion of the functional element is greater than the coefficient of linear expansion of the bus bar, A > B holds, An electronic component.

2. 2.9 ≤ A / B ≤ 8.3 holds, The electronic component according to Claim 1.

3. When a line segment connecting the connection points of the main body portion and the two arm portions is defined as line segment C, Regarding the angle θ [deg] formed by the line segment C and the direction in which at least one of the two arm portions extends, 26.5 ≤ θ ≤ 60 holds, The electronic component according to Claim 1 or 2.

4. Further comprising a sealing body for sealing at least a part of the bus bar and the functional element, The electronic component according to any one of Claims 1 to 3.

5. The functional element is a film capacitor element formed by winding or laminating a metallized film, The metallized film has a dielectric film and a metal layer provided on the dielectric film and electrically connected to the electrode, The electronic component according to any one of Claims 1 to 4.

6. The linear expansion coefficient of the functional element is 4.2×10 －５ / K or more and 1.7×10 －４ / K or less, The electronic component according to any one of Claims 1 to 5.

7. The linear expansion coefficient of the bus bar is 8.5×10 －６ / K or more and 3.4×10 －５ / K or less, The electronic component according to any one of Claims 1 to 6.

8. A plurality of the functional elements are provided, The bus bar includes a plurality of the connection conductors, The plurality of functional elements and the plurality of connection conductors are connected one-to-one, The electronic component according to any one of Claims 1 to 7.

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