Wire Wound Inductor Parts

Abstract

The present invention relates to a winding inductor component. In a winding inductor component, there is a concern that the cover component may be cracked due to expansion and contraction of the cover component. In a winding inductor component (10), a first flange portion (40L) and a second flange portion (40R) are connected to both ends of a winding core portion (30) in the direction of a central axis (CA), and protrude from the winding core portion (30) to both sides in the height direction (Td). The cover portion (70) covers the portion from the upper end of the first flange portion (40L) to the upper end of the winding core portion (30) from the upper side. In a cross-section including the central axis (CA) and along the height direction (Td), the average distance in the height direction (Td) from the upper end of the first flange portion (40L) to the upper end of the cover part (70), i.e., the first average distance (D1), is greater than 25% and less than 45% of the average distance in the height direction (Td) from the upper end of the winding core portion (30) to the upper end of the cover part (70), i.e., the second average distance (D2).

Description

Technical Field

[0001] The present disclosure relates to wirewound inductor components. Background Art

[0002] The core of the wound inductor component described in Patent Document 1 has a columnar winding core portion. A pair of flange portions are connected to both ends of the winding core portion in the direction of the central axis. Each flange portion extends outward from the surface of the winding core portion in a direction perpendicular to the central axis. A terminal electrode is provided at the lower end of each flange portion. In addition, a wire is wound around the winding core portion. The upper surface of the core is covered by a cover member made of epoxy resin. The cover member covers the range from the flange portion on one side to the flange portion on the other side in the direction of the central axis. That is, the cover member covers the pair of flange portions of the core and the wire wound around the winding core portion from the upper side.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2011-171544

[0004] In the wound inductor component described in Patent Document 1, the cover member expands or contracts due to temperature changes. For example, in a thermal shock test assumed to be mounted on a vehicle, since the temperature changes extremely, there is a concern that the cover member may be cracked due to expansion or contraction of the cover member. Summary of the invention

[0005] In order to solve the above-mentioned problems, one embodiment of the present disclosure provides a wound inductor component, which includes: a columnar core portion; a first flange portion and a second flange portion, which are connected to both ends of the core portion in the direction of the central axis when a line passing through the center of the core portion in an extension direction toward the core portion is taken as a central axis and the extension direction of the central axis is taken as a central axis direction, and protrude from the core portion to both sides in a first direction orthogonal to the central axis direction of the core portion; a wire material wound on the core portion; and a cover component covering the wire material from one side in the first direction. The end of the first flange portion on one side in the first direction extends to the portion up to the end of the core portion on one side in the first direction. In a cross-section including the center axis and along the first direction, the average distance in the first direction from the end of the first flange portion on one side in the first direction to the surface of the cover part on one side, i.e., the first average distance, is greater than 25% and less than 45% of the average distance in the first direction from the end of the core portion on one side in the first direction to the surface of the cover part on one side, i.e., the second average distance.

[0006] In order to solve the above-mentioned problems, one method of the present invention provides a wound inductor component, which comprises: a columnar core portion; a first flange portion and a second flange portion, which are connected to both ends of the core portion in the direction of the center axis when a line passing through the center of the core portion in an extension direction toward the core portion is taken as a center axis and the extension direction of the center axis is taken as a center axis direction, and protrude from the core portion to both sides in a first direction orthogonal to the center axis direction of the core portion; a wire material wound on the core portion; and a cover component, which covers a portion from the end of the first flange portion on one side of the first direction to the end of the core portion on one side of the first direction from one side of the first direction, wherein in a cross-section including the center axis and along the first direction, an average distance in the first direction from the end of the first flange portion on one side of the first direction to a surface of the cover component on one side of the surface, i.e., a first average distance, is greater than 40 μm and less than 100 μm.

[0007] According to the above-mentioned structures, a structure can be adopted in which the difference between the thickness of the portion covering the winding core and the thickness of the portion covering the flange in the cover member is not too large. Therefore, even if the cover member is thermally expanded or thermally contracted, the difference in the amount of expansion or contraction between the portion covering the winding core and the portion covering the flange in the cover member will not become too large. Therefore, even if the cover member is exposed to extreme temperature changes such as the assumed vehicle-mounted level, it is possible to suppress damage starting from the portion where the thickness of the cover member changes.

[0008] Even if a thermal shock is applied to the cover member of the wire-wound inductor component, it is possible to suppress the occurrence of damage to the cover member. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a perspective view of the wire wound inductor component according to the first embodiment.

[0010] Figure 2 It is a plan view of the wire wound inductor component according to the first embodiment.

[0011] Figure 3 It is along Figure 2 Cross-sectional view along line 3-3.

[0012] Figure 4 It is along Figure 2 Cross-sectional view along line 4-4.

[0013] Figure 5 It is a cross-sectional view of a wire-wound inductor component according to a second embodiment.

[0014] Figure 6 It is a cross-sectional view of a wire-wound inductor component according to a third embodiment.

[0015] Description of Reference Numerals

[0016] 10…wire-wound inductor component; 20…core body; 30…winding core portion; 31…upper surface; 32…lower surface; 33…side surface; 40…flange portion; 40L…first flange portion; 40R…second flange portion; 41…upper end surface; 42…lower end surface; 43…side surface; 44…inner surface; 45…outer surface; 50…terminal electrode; 50L…first terminal electrode; 50R…second terminal electrode; 60…wire material; 61…upper end surface; 70…cover component; CA…center axis; D1…first average distance; D2…second average distance; D3…third average distance. DETAILED DESCRIPTION

[0017] Hereinafter, various embodiments of the wire-wound inductor component will be described with reference to the accompanying drawings. In addition, the drawings may enlarge the components for easy understanding. The dimensional ratios of the components may differ from the actual ones or from those in other drawings.

[0018] <First embodiment>

[0019] First, a first embodiment of the wire-wound inductor component will be described.

[0020] like Figure 1 As shown in FIG. 1 , in the wound inductor component 10, the core 20 includes a winding core 30 in the shape of a regular quadrangular prism and a pair of flanges 40 connected to both ends of the winding core 30 in the direction of the central axis CA. The material of the core 20 is a magnetic body such as nickel-zinc ferrite. The core 20 is a sintered body formed by sintering a molded body formed by compressing the above-mentioned magnetic body in powder form.

[0021] In the following description, a line passing through the center of the winding core 30 in the extension direction of the winding core 30 is referred to as the central axis CA, and the extension direction of the central axis CA is referred to as the central axis CA direction. Furthermore, the central axis CA direction of the winding core 30 is referred to as the length direction Ld. In addition, when the wound inductor component 10 is mounted on a substrate or the like, when the surface facing the substrate or the like is referred to as the mounting surface, the direction orthogonal to both the length direction Ld and the mounting surface is referred to as the height direction Td. That is, Figure 1 In FIG. 1 , the vertical direction is referred to as the height direction Td. Also, the direction perpendicular to both the length direction Ld and the height direction Td is referred to as the width direction Wd.

[0022] The dimension of the winding core 30 in the longitudinal direction Ld is 800 μm. In addition, the dimension of the winding core 30 in the height direction Td is 400 μm.

[0023] The first flange 40L, one of the pair of flanges 40, is connected to a first end in the direction of the central axis CA of the winding core 30. The first flange 40L is generally flat and substantially rectangular with a small dimension in the longitudinal direction Ld. The first flange 40L is rectangular when viewed in the longitudinal direction Ld.

[0024] like Figure 3 As shown, the upper surface 41 of the first flange portion 40L on the upper side in the height direction Td is parallel to the upper surface 31 of the winding core portion 30 on the upper side in the height direction Td. The lower surface 42 of the first flange portion 40L on the lower side in the height direction Td is parallel to the lower surface 32 of the winding core portion 30 on the lower side in the height direction Td. Figure 2 As shown, the side surfaces 43 on both sides of the surface of the first flange portion 40L in the width direction Wd are parallel to the side surfaces 33 on both sides of the surface of the winding core portion 30 in the width direction Wd. Figure 3 As shown, among the surfaces of the first flange portion 40L, an inner surface 44 on the inner side in the longitudinal direction Ld and an outer surface 45 on the outer side in the longitudinal direction Ld are orthogonal to the longitudinal direction Ld.

[0025] The dimension of the first flange portion 40L in the length direction Ld is 400 μm. The dimension of the first flange portion 40L in the height direction Td is 800 μm. Therefore, the dimension of the first flange portion 40L in the height direction Td is larger than the dimension of the core portion 30 in the height direction Td. Moreover, the first flange portion 40L protrudes from the core portion 30 to both sides in the height direction Td. Therefore, the upper end surface 41 of the first flange portion 40L is located above the upper surface 31 of the core portion 30. In addition, the lower end surface 42 of the first flange portion 40L is located below the lower surface 32 of the core portion 30. In addition, in the present embodiment, the height direction Td is equivalent to the first direction. In addition, the upper side is equivalent to one side of the first direction.

[0026] In addition, the protrusion amount of the first flange portion 40L from the winding core portion 30 is smaller on the upper side than on the lower side. In the present embodiment, the distance from the upper end surface 41 of the first flange portion 40L to the upper surface 31 of the winding core portion 30 is 130 μm. In addition, the distance from the lower end surface 42 of the first flange portion 40L to the lower surface 32 of the winding core portion 30 is 270 μm.

[0027] like Figure 2 As shown, the dimension of the first flange portion 40L in the width direction Wd is larger than the dimension of the core portion 30 in the width direction Wd. Moreover, the first flange portion 40L protrudes from the core portion 30 to both sides in the width direction Wd. The protrusion amount of the first flange portion 40L from the core portion 30 in the width direction Wd is the same on both sides. That is, the central axis CA passes through the center of the first flange portion 40L in the width direction Wd.

[0028] The boundary portions of the surfaces constituting the first flange portion 40L are chamfered. Figure 2 As shown in FIG. 1 , the boundary between the outer surface 45 of the first flange portion 40L and the two side surfaces 43 is an arc-shaped chamfer, that is, an arc-shaped cross section. Figure 3 As shown, the boundary between the outer surface 45 and the upper end surface 41, and the boundary between the outer surface 45 and the lower end surface 42 are both in the shape of arc chamfers. Figure 4 As shown in FIG. 1 , the boundary portions between the two side surfaces 43 of the first flange portion 40L and the upper end surface 41, and the boundary portions between the two side surfaces 43 and the lower end surface 42 are also arc-shaped chamfered shapes. Figure 2 As shown, the boundary between the inner surface 44 of the first flange portion 40L and the two side surfaces 43 is also in an arc-shaped chamfered shape, as shown in FIG. Figure 3 As shown, the boundary portion between the inner surface 44 and the lower end surface 42 is also in an arc chamfered shape. The shape of the boundary portion between the inner surface 44 and the upper end surface 41 of the first flange portion 40L will be described later.

[0029] like Figure 1 As shown in the figure, the second flange portion 40R, which is one of the pair of flange portions 40, is connected to the second end in the direction of the central axis CA of the winding core portion 30. The second flange portion 40R has a shape symmetrical to the first flange portion 40L on the first end side in the direction of the central axis CA. In addition, the shape of each part of the second flange portion 40R is the same as that of the first flange portion 40L, so the same reference numerals are marked and the description is omitted.

[0030] The terminal electrode 50 is provided in the lower part of each flange portion 40 in the height direction Td. Specifically, the first terminal electrode 50L is provided in the lower part of the first flange portion 40L in the height direction Td. The first terminal electrode 50L covers the entire lower end surface 42 of the first flange portion 40L. In addition, the first terminal electrode 50L covers a portion of the lower side of the outer surface 45 of the first flange portion 40L, a portion of the lower side of the two side surfaces 43, and a portion of the lower side of the inner surface 44. In addition, the upper edge of the first terminal electrode 50L is located at a position lower than the lower surface 32 of the winding core portion 30. In addition, the second terminal electrode 50R is provided in the lower part of the second flange portion 40R in the height direction Td. The second terminal electrode 50R has the same structure as the first terminal electrode 50L.

[0031] The wire 60 is wound around the winding core 30. Therefore, the wire 60 is wound in a spiral shape with the central axis CA as the winding center axis. The wire 60 is in direct contact with the surface of the winding core 30. In this embodiment, Figure 3As shown, when a cross-section is observed in a cross-section including the central axis CA and along the height direction Td, the wire 60 is wound in a single layer so as not to overlap in the height direction Td. Therefore, the upper end of each cycle of the wire 60 is in the same position in the height direction Td, and the upper end surface 61 of the wire 60 is a surface formed by connecting the upper end of each cycle of the wire 60. The portion of the wire 60 wound on the winding core 30 does not reach the two flange portions 40 in the length direction Ld. Therefore, at both ends of the winding core 30 in the length direction Ld, that is, near the boundaries with each flange portion 40, there is a portion where the wire 60 is not wound. One end of the wire 60 is connected to the first terminal electrode 50L, and the other end of the wire 60 is connected to the second terminal electrode 50R.

[0032] Although not shown in the figure, the wire 60 has a structure in which wiring made of copper or the like is covered with an insulating coating from the radially outer side. In the present embodiment, the entire wire 60 including the coating has a diameter of 85 μm.

[0033] The core 20 and the wire 60 are covered by the cover member 70 from the upper side in the height direction Td. The cover member 70 covers the upper surface 31 of the winding core 30 and the entire upper end surface 41 of each flange portion 40. Therefore, the cover member 70 covers the portion from the upper end of the first flange portion 40L to the upper end of the winding core 30 and the portion from the upper end of the winding core 30 to the upper end of the wire 60 from the upper side. In addition, the cover member 70 covers a portion of the upper side of the two side surfaces 33 of the winding core 30, a portion of the upper side of the two side surfaces 33 of the two flange portions 40, a portion of the upper side of the outer surface 45 of the two flange portions 40, and a portion of the upper side of the inner surface 44 of the two flange portions 40. In addition, the lower edge of the cover member 70 is located above the lower surface 32 of the winding core 30. Therefore, the cover member 70 covers the portion extending from the first flange portion 40L to the winding core portion 30 and the portion extending from the second flange portion 40R to the winding core portion 30 from the upper side. The portion of the surface of the core 20 and the wire 60 covered by the cover member 70 contacts the cover member 70. The upper surface 71 of the cover member 70, which is the upper side surface in the height direction Td, is a plane parallel to the upper end surface 41 of the first flange portion 40L. The elastic modulus of the cover member 70 is 120 MPa or less. In the present embodiment, the material of the cover member 70 is acrylic resin.

[0034] In addition, the elastic modulus can be measured by using the following apparatus.

[0035] Test equipment: AGSX-5kN (Shimadzu Corporation)

[0036] Measurement conditions: tensile speed 5.0 mm / min

[0037] Here, the shape of the boundary portion between the inner surface 44 of the flange portion 40 and the upper end surface 41 will be described in detail.

[0038] like Figure 3 As shown, when viewed from the width direction Wd, the corner of the first flange portion 40L on the upper side in the height direction Td and on the winding core portion 30 side in the length direction Ld is cut into a triangular shape.

[0039] Specifically, on the surface of the first flange portion 40L, the upper end surface 41 and the inner surface 44 are connected by a covered surface 46. The covered surface 46 is inclined so as to be located on the lower side in the height direction Td as it is closer to the core portion 30 side in the length direction Ld. In the present embodiment, when a cross-sectional observation is made in a cross-section including the central axis CA and along the height direction Td, the covered surface 46 extends in a straight line that is inclined relative to both the height direction Td and the length direction Ld. Moreover, the covered surface 46 is straight in the range of 100 μm including the end on the core portion 30 side of the first flange portion 40L in the length direction Ld. That is, the range of the covered surface 46 in the length direction Ld is less than half of the dimension of the first flange portion 40L in the length direction Ld.

[0040] Here, if Figure 3 As shown, for the core body 20, when a cross-sectional observation is performed in a cross-sectional view including the central axis CA and along the height direction Td, a straight line extending in the height direction Td and passing through the boundary between the winding core portion 30 and the first flange portion 40L is set as a first imaginary straight line VL1. In the present embodiment, the first imaginary straight line VL1 extends along the inner surface 44. In addition, in the first flange portion 40L, when a cross-sectional observation is performed in a cross-sectional view including the central axis CA and along the height direction Td, a straight line extending parallel to the central axis CA and passing through the upper end surface 41 is set as a second imaginary straight line VL2. In the present embodiment, the second imaginary straight line VL2 extends along the upper end surface 41. In addition, in the first flange portion 40L, when a cross-sectional observation is performed in a cross-sectional view including the central axis CA and along the height direction Td, a straight line extending parallel to the central axis CA and passing through the lower end surface 42 is set as a third imaginary straight line VL3. In the present embodiment, the area of ​​the first region E1 surrounded by the first imaginary straight line VL1, the second imaginary straight line VL2, and the surface of the first flange portion 40L is larger than the area of ​​the second region E2 surrounded by the first imaginary straight line VL1, the third imaginary straight line VL3, and the surface of the first flange portion 40L. Similarly, in the second flange portion 40R, the area of ​​the first region E1 is also larger than the area of ​​the second region E2.

[0041] like Figure 3As shown, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the average distance in the height direction Td from the upper end of the first flange portion 40L to the upper surface of the cover member 70 is set as the first average distance D1. In the present embodiment, the upper end of the first flange portion 40L is the upper end surface 41 which is a plane parallel to the central axis CA. In addition, the upper surface of the cover member 70 is the upper surface 71. Therefore, the first average distance D1 is the average distance in the height direction Td from the upper end surface 41 of the first flange portion 40L to the upper surface 71 of the cover member 70, and is specifically 40 μm. In addition, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the second average distance D2 in the height direction Td from the upper surface 31 of the winding core portion 30 to the upper surface 71 of the cover member 70 is 170 μm. In addition, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the average distance in the height direction Td from the upper end of the wire 60 to the upper surface of the cover component 70 is set as the third average distance D3. In the present embodiment, the position of the upper end of the wire 60 in the height direction Td is the position of the upper end surface 61 of the wire 60. Therefore, the third average distance D3 is the average distance in the height direction Td from the upper end surface 61 of the wire 60 to the upper surface 71 of the cover component 70, specifically, 85 μm. In addition, each average distance is determined as: the distance in the height direction Td from each upper end to the upper surface 71 of the cover component 70 is measured at three points in one observation field of view of the cross section along the height direction Td including the central axis CA at 300 times, or the average value of the three measured values ​​obtained by measuring under microscope observation three times. Similarly, each average distance of the second flange portion 40R is also the same value as that of the first flange portion 40L.

[0042] Next, the operation of the first embodiment will be described.

[0043] When the wire 60 of the wound inductor component 10 is energized, the heat generated by the energization is transferred to the cover component 70, and the temperature of the cover component 70 increases. At this time, the cover component 70 thermally expands. The thickness of the cover component 70 in the height direction Td is thinner on the upper end surface 41 of the flange portion 40 and thicker on the winding core portion 30. In addition, the thickness of the cover component 70 is thinner in the portion where the wire 60 is wound on the winding core portion 30, and thicker in the portion where the end of the wire 60 is not wound. In the portion where the thickness of the cover component 70 changes in this way, a load is easily applied to the cover component 70 due to a temperature change caused by a difference in the amount of thermal expansion. In particular, the material of the cover component 70 in the present embodiment is an acrylic resin with a low elastic modulus, so it is possible to prevent damage to the substrate and the core 20 on which the wound inductor component 10 is mounted due to thermal expansion and compression during thermal shock, and the amount of thermal expansion is correspondingly large. Therefore, the load applied to the cover component 70 becomes correspondingly large.

[0044] Next, the effects of the first embodiment will be described.

[0045] (1-1) According to the first embodiment, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the first average distance D1 in the height direction Td from the upper end surface 41 of the first flange portion 40L to the upper surface 71 of the cover component 70 is 40 μm. In addition, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the second average distance D2 in the height direction Td from the upper surface 31 of the winding core portion 30 to the upper surface 71 of the cover component 70 is 170 μm. Therefore, the first average distance D1 is 25% or more and 45% or less of the second average distance D2. That is, the difference between the first average distance D1, which is the thickness of the portion of the cover component 70 covering the flange portion 40, and the second average distance D2, which is the thickness of the portion of the cover component 70 covering the winding core portion 30, is not too large. Therefore, even if the cover member 70 is thermally expanded or contracted, the difference in the amount of expansion or contraction between the portion of the cover member 70 covering the flange portion 40 and the portion covering the winding core portion 30 does not become too large. As a result, even if an excessive thermal shock such as that assumed in a vehicle is applied to the cover member 70, it is possible to suppress damage from occurring at a portion where the thickness of the cover member 70 changes. In addition, since the thickness of the cover member 70 is not excessively large, it is possible to suppress the size of the wound inductor component 10.

[0046] (1-2) According to the first embodiment, in the cross section of the wound inductor component 10 along the height direction Td including the central axis CA, the third average distance D3 in the height direction Td from the upper end surface 61 of the wire 60 to the upper surface 71 of the cover component 70 is 85 μm. Therefore, the third average distance D3 is 50% or more of the second average distance D2. That is, the difference between the thickness of the portion of the cover component 70 covering the winding core 30, that is, the second average distance D2, and the thickness of the portion of the cover component 70 covering the wire 60, that is, the third average distance D3, is not too large. Therefore, even if the cover component 70 is thermally expanded or thermally contracted, the difference in the amount of expansion or contraction between the portion of the cover component 70 covering the winding core 30 and the portion of the cover component 70 covering the wire 60 is not too large. As a result, even if an excessive thermal shock is applied to the cover component 70, it is possible to suppress damage from occurring at a portion of the cover component 70 where the thickness changes.

[0047] (1-3) In the first embodiment, the cover member 70 is made of acrylic resin. Acrylic resin has a low elastic modulus, so it is possible to prevent the substrate and the core 20 on which the wound inductor component 10 is mounted from being damaged by thermal expansion and compression.

[0048] (1-4) In the above-mentioned first embodiment, the upper end surface 41 of the first flange portion 40L is the upper end in the height direction Td. That is, the upper end of the first flange portion 40L is a plane orthogonal to the height direction Td. Therefore, the thickness of the cover part 70 becomes uniform within the corresponding range. Assuming that there are unevenness on the upper surface of the first flange portion 40L, stress may be applied to the parts of the cover part 70 with different thicknesses due to thermal expansion and compression, but in the above-mentioned first embodiment, such stress is not applied. As a result, damage to the cover part 70 when thermal shock is applied can be suppressed within a wider range.

[0049] (1-5) According to the first embodiment, the area of ​​the first region E1 is larger than the area of ​​the second region E2. Moreover, in the first region E1, the thickness of the cover member 70 in the longitudinal direction Ld changes more gradually than when the cover member is provided in the second region E2. By making the thickness of the cover member 70 change more gradually, it is possible to suppress a sharp change in the amount of thermal expansion, thereby suppressing damage to the cover member 70 caused by thermal expansion.

[0050] (1-6) According to the first embodiment, when the cross-section is observed along the height direction Td and includes the central axis CA, the covered surface 46 of the first flange portion 40L is linear. Therefore, the covered surface 46 can be formed by linearly cutting the boundary portion between the upper end surface 41 and the inner surface 44 of the first flange portion 40L, and complex processing is not necessarily required.

[0051] (1-7) According to the first embodiment, the corners of the flange portion 40 are chamfered. For example, the boundary portions between the upper end surface 41 of the first flange portion 40L and the two side surfaces 43, and the boundary portions between the upper end surface 41 of the first flange portion 40L and the outer surface 45 are chamfered. Moreover, the thickness of the cover member 70 covering these chamfered boundary portions gradually changes according to the chamfered shape. By eliminating the portion where the thickness of the cover member 70 changes sharply in this way, damage to the cover member 70 caused by thermal shock can be prevented.

[0052] (1-8) According to the first embodiment, the upper surface 71 of the cover member 70 is a flat surface. Therefore, when the wire-wound inductor component 10 is mounted on a substrate, for example, the upper surface 71 of the cover member 70 can be sucked by a suction nozzle to facilitate transportation.

[0053] <Second embodiment>

[0054] A second embodiment of the wire-wound inductor component will be described below. In the wire-wound inductor component 110 of the second embodiment, the main difference from the first embodiment is the shape of the covered surface 146 of the flange portion 40 of the core 20. In the following description, the same reference numerals are given to the same structures as those in the first embodiment, and the description is omitted or simplified.

[0055] like Figure 5 As shown, the covered surface 146 of the first flange portion 40L includes a first inclined surface 146A, a flat surface 146B, and a second inclined surface 146C.

[0056] In the cross section of the wound inductor component 110 including the central axis CA and along the height direction Td, a first inclined surface 146A is provided at the end of the covered surface 146 on the side of the winding core 30 in the length direction Ld. The end of the first inclined surface 146A on the side of the winding core 30 in the length direction Ld is connected to the end of the first end side of the upper surface 31 of the winding core 30 in the length direction Ld. The first inclined surface 146A extends obliquely with respect to the upper surface 31 of the winding core 30 so as to be located more on the upper side in the height direction Td toward the first end side in the length direction Ld. The end of the first end side of the first inclined surface 146A in the length direction Ld is located approximately in the middle of the position of the upper surface 31 of the winding core 30 and the position of the upper end surface 41 of the first flange portion 40L in the height direction Td.

[0057] In the cross section along the height direction Td and including the central axis CA, the flat surface 146B is connected to the end of the first end side in the length direction Ld of the first inclined surface 146A. In the cross section along the height direction Td and including the central axis CA, the flat surface 146B extends parallel to the length direction Ld. The position of the flat surface 146B in the height direction Td is the middle position between the upper surface 31 of the winding core 30 and the upper end surface 41 of the first flange 40L. The end of the first end side in the length direction Ld of the flat surface 146B reaches approximately the center in the length direction Ld of the first flange 40L.

[0058] In the cross section including the central axis CA and along the height direction Td, the second inclined surface 146C is connected to the end of the first end side in the length direction Ld of the flat surface 146B. The second inclined surface 146C extends obliquely with respect to the upper surface 31 of the winding core 30 so as to be located on the upper side in the height direction Td as it goes toward the first end side in the length direction Ld. The end of the first end side in the length direction Ld of the second inclined surface 146C is connected to the upper end surface 41 of the first flange portion 40L.

[0059] Thus, in the cross section along the height direction Td including the central axis CA, the flat surface 146B extends between the first inclined surface 146A and the second inclined surface 146C in the covered surface 146 of the first flange portion 40L. Therefore, two steps are formed between the upper end surface 41 of the first flange portion 40L and the upper surface 31 of the winding core portion 30, sandwiching the flat surface 146B.

[0060] In the cross section along the height direction Td including the central axis CA, the step distance D4 in the height direction Td from the flat surface 146B to the upper surface 71 of the cover member 70 is 105 μm. Therefore, the step distance D4 is at least twice the first average distance D1 and smaller than the second average distance D2.

[0061] Here, as in the first embodiment, the first imaginary straight line VL1, the second imaginary straight line VL2, and the third imaginary straight line VL3 are drawn. At this time, the area of ​​the first region E11 surrounded by the first imaginary straight line VL1, the second imaginary straight line VL2, and the surface of the first flange portion 40L is larger than the area of ​​the second region E2 surrounded by the first imaginary straight line VL1, the third imaginary straight line VL3, and the surface of the first flange portion 40L.

[0062] In addition, in the second embodiment, the shape of the mask surface 146 is different from that of the first embodiment. Therefore, the shape of the first area E11 in the second embodiment is different from that of the first area E1 in the first embodiment. In particular, the area of ​​the first area E11 in the second embodiment is larger than that of the first area E1 in the first embodiment.

[0063] Next, the operation and effects of the second embodiment are described. According to the second embodiment, in addition to the effects (1-1) to (1-8) described above, the following effects are achieved.

[0064] (2-1) According to the second embodiment, when the cross-section is observed in a cross section including the central axis CA and along the height direction Td, the covered surface 146 of the first flange portion 40L has a first inclined surface 146A, a flat surface 146B, and a second inclined surface 146C. By providing the flat surface 146B, the thickness of the cover member 70 covering the flat surface 146B is greater than the thickness of the cover member 70 covering the upper end surface 41 of the first flange portion 40L, and is smaller than the thickness of the upper surface 31 of the core portion 30. Therefore, compared with the case where the upper end surface 41 of the first flange portion 40L and the upper surface 31 of the core portion 30 are connected by a single inclined surface, the thickness of the cover member 70 can be changed more gradually.

[0065] (2-2) According to the second embodiment, the step distance D4 is more than twice the first average distance D1. Therefore, the thickness of the upper portion of the flat surface 146B is correspondingly greater than the upper portion of the upper end surface 41 of the first flange portion 40L where the thickness of the cover member 70 becomes the smallest. Therefore, it is possible to suppress damage to the cover member 70 at the upper portion of the flat surface 146B due to excessive thermal shock to the cover member 70.

[0066] <Third Embodiment>

[0067] A third embodiment of a wire-wound inductor component will be described below. The wire-wound inductor component 210 of the third embodiment is mainly different from the first embodiment in the shape of the flange portion 40. In the following description, the same reference numerals are used for the same structures as those of the first embodiment, and the description is omitted or simplified.

[0068] like Figure 6 As shown, the boundary between the upper end surface 41 and the inner surface 44 of the first flange portion 40L is an arc chamfered shape. The arc chamfered shape of the boundary between the upper end surface 41 and the inner surface 44 is the same as the arc chamfered shape of the boundary between other surfaces, such as the upper end surface 41 and the outer surface 45.

[0069] Hereinafter, the results of actually manufacturing and evaluating an example of the wire-wound inductor component 210 will be described.

[0070] As an embodiment and a comparative example of the wound inductor component 210, samples with different first average distances D1 of the cover component 70 were prepared. Specifically, as a comparative example, a sample with a first average distance D1 of 20 μm and a sample with a first average distance D1 of 30 μm were prepared. In addition, as an embodiment, samples with first average distances D1 of 40 μm, 50 μm, 60 μm, 70 μm, 80 μm, 90 μm, and 100 μm were prepared. In addition, the distance from the upper end surface 41 of the first flange portion 40L to the upper surface 31 of the winding core portion 30 is 130 μm. Therefore, the second average distance D2 is "130+D1" μm.

[0071] For these samples, a heat shock test of -55°C to 125°C was performed for 2000 cycles. For each sample after the heat shock test, the cover part 70 was observed using an optical microscope and an electron microscope to confirm whether there was any cracking. As a result, cracking was confirmed in the sample of the comparative example, but no cracking was confirmed in the sample of the embodiment. In other words, it was found that the first average distance D1 was ensured to be greater than 40μm, and the ratio to the second average distance D2 was ensured to be greater than 25%, thereby preventing damage to the cover part 70.

[0072] Next, the effects of the third embodiment will be described. According to the third embodiment, in addition to the effects of (1-4), (1-7), and (1-8) described above, the following effects are achieved.

[0073] (3-1) In the third embodiment, the first average distance D1, that is, the thickness of the cover member 70 on the first flange portion 40L is ensured to be 40 μm or more, and the ratio to the second average distance D2 is ensured to be 25% or more, thereby suppressing damage to the cover member 70 caused by thermal shock. Therefore, it is not necessary to change the shape of the first flange portion 40L according to the conventional technology, and damage to the cover member 70 can be prevented by adjusting the thickness of the cover member 70.

[0074] The above-mentioned embodiments can be implemented by modification as follows. The embodiments and the following modification examples can be implemented in combination within the range of no technical contradiction.

[0075] In the above-mentioned embodiments, among the corners of the flange portion 40, except for the boundary portion between the upper end surface 41 and the inner surface 44, other boundary portions may not be chamfered. In addition, regardless of the method of processing the corners of the core body 20 into a chamfered shape, the mold used to mold the core body 20 may be a chamfered shape, or the core body 20 after molding may be chamfered by roller processing.

[0076] In the above-mentioned embodiments, the size of the core 20 is not limited to the example of the above-mentioned embodiment. Regardless of the size of the core 20, damage to the cover member 70 can be suppressed as long as the first average distance D1 is 25% or more of the second average distance D2.

[0077] In the above-mentioned embodiments, the material of the core 20 is not limited to the examples in the above-mentioned embodiments. For example, the material of the core 20 may be alumina or resin. In addition, the core 20 may be a molded body of resin.

[0078] In each of the above-mentioned embodiments, the shape of the core portion 30 can be any columnar shape, and can be a cylindrical shape or a polygonal columnar shape. In addition, at the boundary portion between the core portion 30 and the flange portion 40, the end of the core portion 30 can be expanded so that the closer it is to the flange portion 40, the farther it is from the center axis CA. In this case, the boundary between the core portion 30 and the flange portion 40 is the inner surface 44 that is orthogonal to the length direction Ld. In addition, in the case where the flange portion 40 does not have a surface orthogonal to the length direction Ld, in the cross-section containing the center axis CA, if there is an angle between the surface of the flange portion 40 and the surface of the core portion 30, the angle is the boundary, and if there is an inflection point, the inflection point is the boundary.

[0079] In each of the above-mentioned embodiments, the shape of the flange portion 40 may be spherical or polygonal. That is, a part or all of the surface of the flange portion 40 may be formed by a curved surface. It is sufficient that at least the flange portion 40 protrudes to both sides of the height direction Td of the winding core portion 30 when viewed from the direction of the central axis CA. In addition, the protrusion amount of the flange portion 40 from the winding core portion 30 to the upper side may be less than the protrusion amount of the flange portion 40 from the core portion 30 to the lower side.

[0080] In the first and second embodiments described above, the surface constituting the covered surface may not have a portion extending in a straight line in the cross section. For example, the first inclined surface 146A and the second inclined surface 146C in the second embodiment may also be curved surfaces. In addition, the covered surface 46 in the first embodiment may be entirely curved surfaces, i.e., arc-shaped in the cross section. In this case, the covered surface 46 can be formed by arc processing. In addition. For example, the covered surface may also be a combination of straight lines and curves.

[0081] ·In the above-mentioned second embodiment, more than three steps may be provided in the covered surface 146. In this case, the step distance of each step in the height direction Td is preferably more than twice the step distance of other steps located above the step. More specifically, in this case, a plurality of flat surfaces are provided, and another flat surface is located above one flat surface and on the opposite side of the winding core portion 30 in the length direction Ld. Moreover, the step distance at one flat surface may be more than twice the step distance at another flat surface. In this case, the difference in thickness of the cover part 70 between the steps becomes smaller. Therefore, by increasing the difference in thickness of the cover part 70 between the steps, it is possible to prevent the cover part 70 from expanding and contracting and being damaged when a thermal shock is applied to the cover part 70 on the upper part of the step. In particular, it is preferred when the protrusion of the flange portion 40 from the winding core portion 30 to the upper side is large compared to the above-mentioned embodiments.

[0082] In the first and second embodiments, the area of ​​the first region may be smaller than the area of ​​the second region E2. Even if the area of ​​the first region is small, as long as the first average distance D1 is greater than 40 μm, or the first average distance D1 is greater than 25% of the second average distance D2, damage to the cover member 70 can be prevented. However, if the first average distance D1 exceeds 45% of the second average distance D2, the dimension of the height direction Td of the wound inductor component becomes larger, and the effect of preventing damage to the cover member 70 reaches a limit. Therefore, from the perspective of miniaturization of the wound inductor component, the first average distance D1 needs to be less than 45% of the second average distance D2.

[0083] In the above-mentioned embodiments, the position of the terminal electrode 50 is not limited to the example of the above-mentioned embodiment. For example, the terminal electrode 50 may be arranged only on the lower end surface 42 of the flange portion 40 .

[0084] In each of the above embodiments, the terminal electrode 50 may be formed by stacking a plurality of metal layers. For example, layers of silver, copper, nickel, and tin may be stacked in sequence. In addition, the terminal electrode 50 may be formed by sintering or plating a conductor, or by attaching a metal plate.

[0085] In the above-mentioned embodiments, the diameter of the wire 60 is not limited to the example of the above-mentioned embodiment. By changing the diameter of the wire 60, the ratio of the third average distance D3 to the second average distance D2 also changes, but the ratio of the third average distance D3 to the second average distance D2 can be less than 50%, or less than 85 μm. In addition, the diameter of the wire 60 is preferably greater than 15 μm and less than 85 μm.

[0086] In each of the above embodiments, a plurality of wires 60 may be wound around the winding core 30. In this case, the number of terminal electrodes 50 may be increased along with the number of ends of the wires 60. In this case, the upper end surface 61 of the wire 60 is a surface formed by connecting the upper ends of the wires 60 wound on the outermost side.

[0087] In each of the above-mentioned embodiments, the material of the cover part 70 is not limited to acrylic resin. For example, the material of the cover part 70 may be polyurethane resin, epoxy resin, or silicone resin. In addition, the elastic modulus of the cover part 70 is not limited to the example of the above-mentioned embodiment. For example, the elastic modulus of the material of the cover part 70 is 6 GPa or less, thereby preventing peeling at the contact portion between the core 20 and the cover part 70. In particular, the elastic modulus of the material of the cover part 70 is 120 MPa or less, thereby ensuring greater reliability with respect to peeling. In addition, the elastic modulus of the material of the cover part 70 is 0.5 MPa or more, thereby preventing the winding-type inductor parts 10 from adhering to each other during transportation and installation of the winding-type inductor parts 10.

[0088] In each of the above-mentioned embodiments, the cover member 70 may not completely cover the upper side of the core 20 and the wire 60. It is sufficient as long as it covers at least from the upper end of the first flange portion 40L to the upper end of the winding core portion 30. In addition, when the third average distance D3 is smaller than 50% of the second average distance D2 and smaller than 85 μm, the cover member 70 may not cover the upper end of the wire 60 from the upper side.

Claims

1. A wire-wound inductor component, wherein: have: A columnar core; The first flange portion and the second flange portion are connected to both ends of the core portion in the direction of the central axis when a line passing through the center of the core portion in the extension direction toward the core portion is taken as the central axis and the extension direction of the central axis is taken as the central axis direction, and protrude from the core portion to both sides in a first direction orthogonal to the central axis direction of the core portion; A wire material is wound around the winding core; as well as a cover member that covers a portion extending from an end of the first flange portion on one side in the first direction to an end of the winding core portion on one side in the first direction from one side in the first direction, In a cross-section including the center axis and along the first direction, the average distance in the first direction from the end of the first flange portion on one side in the first direction to the surface of the cover part on one side, i.e., the first average distance, is greater than 25% and less than 45% of the average distance in the first direction from the end of the core portion on one side in the first direction to the surface of the cover part on one side, i.e., the second average distance.

2. The wire-wound inductor component according to claim 1, wherein: The cover member covers a portion extending from an end of the winding core on one side in the first direction to an end of the wire on one side in the first direction from the first direction. In a cross section including the central axis and along the first direction, a third average distance which is an average distance in the first direction from an end of the wire on one side in the first direction to a surface on one side of the surface of the cover component is greater than 50% of the second average distance.

3. A wire-wound inductor component, wherein: have: A columnar core; The first flange portion and the second flange portion are connected to both ends of the central axis direction of the core portion when a line passing through the center of the core portion in an extension direction toward the core portion is taken as a central axis and the extension direction of the central axis is taken as a central axis direction, and protrude from the core portion to both sides in a first direction orthogonal to the central axis direction of the core portion; A wire material is wound around the winding core; as well as a cover member that covers a portion extending from an end of the first flange portion on one side in the first direction to an end of the winding core portion on one side in the first direction from one side in the first direction, In a cross section including the central axis and along the first direction, an average distance in the first direction from an end of the first flange portion on one side in the first direction to a surface of the cover component on one side, i.e., a first average distance, is greater than or equal to 40 μm and less than or equal to 100 μm.

4. The wire-wound inductor component according to claim 3, wherein: The cover member covers a portion extending from an end of the winding core on one side in the first direction to an end of the wire on one side in the first direction from the first direction. In a cross section along the first direction including the central axis, a third average distance in the first direction from an end of the wire on one side in the first direction to a surface on one side of the surface of the cover member is 85 μm or more.

5. The wire-wound inductor component according to any one of claims 1 to 4, wherein: The cover component is made of acrylic resin.

6. The wire-wound inductor component according to any one of claims 1 to 4, wherein: An end of the first flange portion on one side in the first direction is a plane perpendicular to the first direction.

7. The wire-wound inductor component according to any one of claims 1 to 4, wherein: The cover member has an elastic modulus of 120 MPa or less.

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