Coil device

Abstract

To provide a coil device with high reliability.SOLUTION: An inductor 1 has a coil 2 composed of a rectangular wire, a first terminal 4a including a first connection part 42a formed with a first accommodation recess 421a in which a first draw part 3a of the coil 2 is accommodated, and a second terminal 4b including a second connection part 42b formed with a second accommodation recess 421b in which a second draw part 3b of the coil 2 is accommodated. The first accommodation recess 421a and the second accommodation recess 421b are displaced along the axial direction of the winding of the coil 2.SELECTED DRAWING: Figure 7A

Description

[Technical field]

[0001] The present invention relates to a coil device used, for example, as an inductor. [Background technology]

[0002] A coil device used as an inductor or the like is known that has a body, a coil embedded inside the body, and a terminal disposed inside the body as a connection part to which the lead-out part of the coil is connected (Patent Document 1). In the coil device described in Patent Document 1, the lead-out part of the coil can be connected to the connection part by crimping the terminal to the lead-out part of the coil.

[0003] In the coil device described in Patent Document 1, the coil is formed from wire, so it is possible to crimp a terminal to the lead-out portion of the coil without causing any problems. However, when the coil is formed from rectangular wire, it is difficult to crimp a terminal to the lead-out portion of the coil, and there is room for improvement. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Utility Model Application Publication No. 3-51807 Summary of the Invention [Problem to be solved by the invention]

[0005] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a coil device that allows the lead-out portion of the coil to be easily connected to a terminal. [Means for solving the problem]

[0006] In order to achieve the above object, a coil device according to a first aspect of the present invention comprises: A coil made of a rectangular wire; a first terminal including a first connecting portion having a first accommodating recess formed therein for accommodating a first drawn-out portion of the coil; a second terminal including a second connection portion having a second accommodating recess formed therein for accommodating the second lead portion of the coil; The first accommodating recess and the second accommodating recess are misaligned along the winding axis direction of the coil.

[0007] In the coil device according to the first aspect of the present invention, a first accommodating recess for accommodating a first lead portion of the coil is formed in the first connection portion, and a second accommodating recess for accommodating a second lead portion of the coil is formed in the second connection portion. Therefore, by accommodating the first lead portion in the first accommodating recess, it is possible to connect the first lead portion to the first connection portion, and it is not necessary to crimp the first terminal to the first lead portion when connecting the first lead portion to the first connection portion, and it is possible to easily connect the first lead portion to the first terminal. Similarly, by accommodating the second lead portion in the second accommodating recess, it is possible to connect the second lead portion to the second connection portion, and it is not necessary to crimp the second terminal to the second lead portion when connecting the second lead portion to the second connection portion, and it is possible to easily connect the second lead portion to the second terminal.

[0008] In particular, in the coil device according to the present invention, the first accommodating recess and the second accommodating recess are misaligned along the winding axis direction of the coil. Therefore, even if the first extracting position of the first extracting portion and the second extracting position of the second extracting portion are misaligned along the winding axis direction of the coil, the first extracting portion and the second extracting portion can be respectively extracted to the first terminal and the second terminal without unnecessarily bending the first extracting portion or the second extracting portion. Therefore, in this respect as well, the first extracting portion can be easily connected to the first terminal, and the second extracting portion can be easily connected to the second terminal.

[0009] Preferably, the first connection portion and the second connection portion extend along the winding axis direction at different positions, and the length of the first connection portion along the winding axis direction is longer than the length of the second connection portion along the winding axis direction. With this configuration, it is possible to dispose the first accommodating recess and the second accommodating recess at positions offset from each other along the winding axis direction of the coil by a distance corresponding to the difference between the length of the first connection portion along the winding axis direction and the length of the second connection portion along the winding axis direction, and the above-mentioned effect can be obtained with a simple configuration.

[0010] Preferably, the first terminal has a first base portion on which the first connection portion is raised along the winding axis direction, the second terminal has a second base portion on which the second connection portion is raised along the winding axis direction, and the second lead-out portion of the coil accommodated in the second accommodating recess is in contact with the second base portion. With this configuration, the second lead-out portion is supported by the second base portion, so that even if an external force acts on the second lead-out portion, the second lead-out portion is less likely to shift in position in the winding axis direction. Therefore, it is possible to determine the position of the second lead-out portion at a predetermined position, and it is possible to prevent inductance characteristics and the like from varying from product to product due to variations in the position of the second lead-out portion.

[0011] Preferably, the first lead portion of the coil accommodated in the first accommodating recess is located above a bottom of the first accommodating recess. With this configuration, even if the first lead position of the first lead portion is shifted in the winding axis direction due to, for example, a manufacturing error, the first lead portion can be connected to the first terminal in a state in which it is linearly drawn out without bending the first lead portion when accommodating it in the first accommodating recess.

[0012] Furthermore, in the above configuration, a gap (margin) is formed between the first drawn-out portion and the bottom of the first accommodating recess, but by making the first accommodating recess relatively deep in advance so that such a margin is formed, the first drawn-out portion can be reliably accommodated in the first accommodating recess without tilting the coil. Furthermore, even if a situation arises in which the first drawn-out position of the first drawn-out portion is positioned at a different position from normal along the winding axis direction due to a design change, for example, the first drawn-out portion can be reliably accommodated in the first accommodating recess.

[0013] Preferably, the first accommodating recess is a first notch formed in the first connecting portion along the winding axis direction, and the second accommodating recess is a second notch formed in the second connecting portion along the winding axis direction. In this configuration, for example, the first lead-out portion can be easily accommodated in the first accommodating recess by inserting the first lead-out portion from a top of the first connecting portion along the winding axis direction into the first accommodating recess. The same applies to the second lead-out portion, and for example, the second lead-out portion can be easily accommodated in the second accommodating recess by inserting the second lead-out portion from a top of the second connecting portion along the winding axis direction into the second accommodating recess.

[0014] Preferably, the first connecting wire portion is formed with a pair of first protrusions sandwiching the first accommodating recess therebetween, and the second connecting wire portion is formed with a pair of second protrusions sandwiching the second accommodating recess therebetween, the pair of first protrusions being connected to each other by a joint, and the pair of second protrusions being connected to each other by a joint. By arranging the first drawn-out portion so as to be sandwiched between each of the pair of first protrusions, the first drawn-out portion can be stably accommodated in the first accommodating recess, and by joining each of the pair of first protrusions in this state with a joint, the first drawn-out portion can be effectively prevented from coming off the first accommodating recess. Similarly, by arranging the second drawn-out portion so as to be sandwiched between each of the pair of second protrusions, the second drawn-out portion can be stably accommodated in the second accommodating recess, and by joining each of the pair of second protrusions in this state with a joint, the second drawn-out portion can be effectively prevented from coming off the second accommodating recess.

[0015] Preferably, when the first connection wire portion and the second connection wire portion are viewed from the front, the first accommodating recess and the second accommodating recess are disposed inward from the outer periphery of the coil in a direction perpendicular to the winding axis direction. In this configuration, the distance between the first accommodating recess and the second accommodating recess is narrower than the distance between the first drawn-out position of the first drawn-out portion and the second drawn-out position of the second drawn-out portion, and the first accommodating recess and the second accommodating recess are disposed between the first drawn-out position and the second drawn-out position. In this state, in order to accommodate the first drawn-out portion in the first accommodating recess, it is necessary to bend the first drawn-out portion inward from the first drawn-out position toward the first accommodating recess. As a result, a biasing force is generated in the first drawn-out portion, and when the first drawn-out portion is accommodated in the first accommodating recess, the first drawn-out portion can be fixed in the first accommodating recess with sufficient fixing strength by the elastic force of the first drawn-out portion. Similarly, the second drawn-out portion can be fixed in the second accommodating recess with sufficient fixing strength.

[0016] Preferably, the first and second drawn-out portions are drawn out in substantially the same direction, and the first connection portion and the second connection portion are disposed on one side of the coil from which the first and second drawn-out portions are drawn out. With this configuration, when the first and second connection portions are, for example, laser-welded, it is possible to irradiate each connection portion with a laser from substantially the same direction, which makes laser welding easy and facilitates manufacturing.

[0017] In order to achieve the above object, a coil device according to a second aspect of the present invention comprises: The body and A coil made of a rectangular wire and embedded inside the element body; a first terminal including a first connection portion to which a first lead portion of the coil is connected, the first connection portion being disposed inside the body; a second connection portion to which a second lead portion of the coil is connected, the second connection portion being disposed inside the body; and a second terminal, The first connecting wire portion has a first accommodating recess in which the first drawn-out portion is accommodated, The second connecting portion has a second accommodating recess formed therein for accommodating the second drawn-out portion.

[0018] In the coil device according to the second aspect of the present invention, similarly to the coil device according to the first aspect, the first lead portion can be connected to the first connecting portion by accommodating the first lead portion in the first accommodating recess, and the first lead portion can be easily connected to the first terminal without the need to crimp the first terminal to the first lead portion when connecting the first lead portion to the first connecting portion. Similarly, the second lead portion can be connected to the second connecting portion by accommodating the second lead portion in the second accommodating recess, and the second lead portion can be easily connected to the second terminal without the need to crimp the second terminal to the second lead portion when connecting the second lead portion to the second connecting portion.

[0019] Furthermore, in the coil device of the present invention, the first connecting wire portion having the first accommodating recess and the second connecting wire portion having the second accommodating recess are arranged inside the body, and the coil is made of flat wire. As a result, it is possible to easily manufacture a surface-mounted coil device that is capable of passing a large current while allowing each lead-out portion to be easily connected to each terminal as described above. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a perspective view of a coil device according to an embodiment of the present invention. [Diagram 2] FIG. 2 is a perspective view showing an internal configuration of the coil device shown in FIG. [Diagram 3] FIG. 3 is a perspective view showing the configuration of a first core used when forming the base body of the coil device shown in FIG. [Figure 4] FIG. 4 is a perspective view showing the configuration of a second core used when forming the base body of the coil device shown in FIG. [Diagram 5] FIG. 5 is a perspective view showing the configuration of the coil shown in FIG. [Figure 6] FIG. 6 is a perspective view showing a configuration of a pair of terminals shown in FIG. [Figure 7A] FIG. 7A is a side view showing a state in which a coil is placed on each base portion of the pair of terminals shown in FIG. [Figure 7B] FIG. 7B is a perspective view showing the pair of terminals and the coil shown in FIG. 7A when viewed from a different angle. [Figure 8] FIG. 8 is a plan view showing the configuration of the coil device shown in FIG. [Figure 9A] FIG. 9A is a diagram showing a manufacturing method of the coil device shown in FIG. [Figure 9B] FIG. 9B is a diagram showing a process subsequent to that of FIG. 9A. [Figure 9C] FIG. 9C is a diagram showing a process subsequent to that of FIG. 9B. [Figure 9D] FIG. 9D is a diagram showing a step subsequent to that of FIG. 9C. [Figure 9E]FIG. 9E is a diagram showing a step subsequent to that of FIG. 9D. [Figure 9F] FIG. 9F is a diagram showing a step subsequent to that of FIG. 9E. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] Hereinafter, the present invention will be described based on the embodiments shown in the drawings.

[0022] As shown in Fig. 1, an inductor 1 according to an embodiment of the present invention is a surface mount type inductor having a substantially rectangular parallelepiped shape. In Fig. 1, the surface of the inductor 1 on the negative side of the Z axis is a mounting surface 8a, which is disposed facing a circuit board or the like. Hereinafter, the surface of the inductor 1 opposite to the mounting surface is referred to as a non-mounting surface 8b.

[0023] As shown in Fig. 2, the inductor 1 has a coil 2, a pair of terminals 4a, 4b, and a core (element body) 8. Note that in Fig. 2, the inductor 1 shown in Fig. 1 is shown rotated by 180° along the XZ plane, with the mounting surface 8a of the inductor 1 disposed at the upper side of the paper and the non-mounting surface 8b of the inductor 1 disposed at the lower side of the paper. In the following, for ease of understanding, the upper side of the paper will be referred to as the upside, and the lower side of the paper will be referred to as the downside.

[0024] The dimensions of inductor 1 are not particularly limited, but its width in the X-axis direction is preferably 2 to 20 mm, its width in the Y-axis direction is preferably 2 to 20 mm, and its width in the Z-axis direction is preferably 1 to 10 mm.

[0025] The core 8 is made of a mixture containing magnetic powder and binder resin, and is formed by combining the first core 5 shown in FIG. 3 and the second core 6 shown in FIG. 4. That is, the core 8 is formed by compressing the first core 5 and the second core 6, which have been molded in advance, in a mold and integrating them. At the joint between the first core 5 and the second core 6, the boundary cannot be identified, and they are integrated together. The configurations of the first core 5 and the second core 6 will be described below.

[0026] 3, the first core 5 has a core base portion 50 and a columnar portion 51 formed on the surface (upper surface) of the core base portion 50. The first core 5 mainly forms a part of the anti-mounting surface 8b side of the core 8 shown in FIG.

[0027] The first core 5 is made of a synthetic resin in which ferrite particles or metal magnetic particles are dispersed. However, the material constituting the first core 5 is not limited to this, and may be made of a synthetic resin that does not contain these particles. Examples of ferrite particles include Ni-Zn ferrite and Mn-Zn ferrite. Examples of metal magnetic particles include, but are not limited to, Fe-Ni alloy powder, Fe-Si alloy powder, Fe-Si-Cr alloy powder, Fe-Co alloy powder, Fe-Si-Al alloy powder, and amorphous iron.

[0028] The synthetic resin contained in the first core 5 is not particularly limited, but preferable examples include epoxy resin, phenol resin, polyester resin, polyurethane resin, polyimide resin, and silicone resin.

[0029] The core base portion 50 has a substantially rectangular parallelepiped shape (substantially flat shape), and in a state where the first core 5 is combined with the second core 6 (FIG. 4), the lower surface of the core base portion 50 forms the counter-mount surface 8b of the core 8 shown in FIG. 1 and FIG. 2. Two step portions 500 and a step upper portion 501 located between the step portions 500 are formed on the surface (upper surface) of the core base portion 50. The step upper portion 501 forms the upper surface of the step with respect to the step portion 500, and a columnar portion 51 is formed in the step upper portion 501. The width of the step upper portion 501 in the Y-axis direction matches the width of the core base portion 50 in the Y-axis direction, and the step portion 501 is formed from one end to the other end of the core base portion 50 in the Y-axis direction. The ratio of the width of the step upper portion 501 in the X-axis direction to the width of the core base portion 50 in the X-axis direction is preferably 1 / 4 to 1 / 2.

[0030] One of the step portions 500 is formed on the negative X-axis direction side of the core base portion 50, with the columnar portion 51 sandwiched therebetween. The other step portion 500 is formed on the positive X-axis direction side of the core base portion 50, with the columnar portion 51 sandwiched therebetween. Each step portion 500 has the same shape when viewed from the Z-axis direction, and is generally rectangular in shape with a predetermined length in each of the X-axis and Y-axis directions.

[0031] The width of each step 500 in the Y-axis direction is equal to the width of the core base portion 50 in the Y-axis direction, and each step 500 is formed from one end of the core base portion 50 in the Y-axis direction to the other end. The width of one step 500 in the X-axis direction is approximately equal to the distance from the end of the columnar portion 51 on the X-axis negative side to the end of the core base portion 50 on the X-axis negative side, and one step 500 is formed from the position of the end of the columnar portion 51 on the X-axis negative side to the end of the core base portion 50 on the X-axis negative side in the X-axis direction. The width of the other step 500 in the X-axis direction is approximately equal to the distance from the end of the columnar portion 51 on the X-axis positive side to the end of the core base portion 50 on the X-axis positive side, and the other step 500 is formed from the position of the end of the columnar portion 51 on the X-axis positive side to the end of the core base portion 50 on the X-axis positive side in the X-axis direction.

[0032] 6 are disposed on each step 500 during manufacturing of the inductor 1, which makes it possible to position the terminals 4a, 4b relative to the base portions 41a, 41b at the position of each step 500. Furthermore, by disposing the base portions 41a, 41b of the terminals 4a, 4b on each step 500, it is possible to prevent the terminals 4a, 4b from shifting in position.

[0033] From the viewpoint of effectively performing such positioning, the depth D1 of the step portion 500 along the Z-axis direction is determined based on the thickness T1 (FIG. 6) of the base portions 41a, 41b, and the ratio D1 / T1 of the depth D1 to the thickness T1 is preferably 1 / 8≦D1 / T1≦2, and more preferably 1 / 4≦D1 / T1≦1. In particular, it is preferable that the depth D1 of the step portion 500 along the Z-axis direction is approximately equal to the thickness T1 of the base portions 41a, 41b so that when the base portions 41a, 41b are arranged in each step portion 500, the surfaces (upper surfaces) of the base portions 41a, 41b and the surface of the step upper portion 501 are flush with each other.

[0034] A first recess 52 is formed on each side surface of the core base portion 50 in the X-axis direction. The connection portions 43a, 43b of the terminals 4a, 4b shown in FIG. 6 are disposed in each first recess 52. The depth of the first recess 52 along the X-axis direction is not particularly limited, but is approximately the same as or greater than the thickness of the connection portions 43a, 43b shown in FIG. 6. It is preferable that the depth of each first recess 52 along the X-axis direction is deep enough that the surfaces of the connection portions 43a, 43b do not protrude from each first recess 52 when the connection portions 43a, 43b are disposed in each first recess 52. The width of the first recess 52 in the Y-axis direction is preferably 1 / 3 to 3 / 4 of the width of the core base portion 50 in the Y-axis direction, and is preferably approximately equal to the width of the connection portions 43a, 43b in the Y-axis direction shown in FIG.

[0035] The columnar portion 51 is integrally formed at approximately the center of the core base portion 50 and extends along the Z-axis direction. More specifically, the position (axis center) of the columnar portion 51 is shifted by a predetermined distance from the center of the core base portion 50 toward the negative Y-axis direction.

[0036] 5 is disposed (inserted or wound) on the columnar portion 51. Therefore, the diameter of the columnar portion 51 is smaller than the inner diameter of the coil 2. Also, as described above, the position of the columnar portion 51 is shifted toward the negative Y-axis direction with respect to the center of the core base portion 50, so that when the first core 5 is combined with the second core 6 (FIG. 4), the center (winding axis) of the coil 2 is shifted toward the negative Y-axis direction with respect to the center of the core 8 shown in FIG. 2.

[0037] The columnar portion 51 has a cylindrical shape, and preferably has a height greater than that of the coil 2. Providing the first core 5 with the columnar portion 51 makes it possible to ensure a sufficient effective permeability of the first core 5 in the region inside the coil 2, thereby making it possible to improve the inductance characteristics of the inductor 1.

[0038] As shown in FIG. 4, the second core 6 has a substantially square ring shape, and is placed on the surface (upper surface) of the first core 5 shown in FIG. 3, and is combined with the first core 5 in a state in which the coil 2 is attached. The second core 6 may be made of the same material as the first core 5, or may be made of a different material. The second core 6 has a main body 60, an accommodating hole 61, terminal accommodating grooves 62a, 62b, connecting grooves 63a, 63b, a second recess 64, a third recess 65 (FIG. 9C), and a bottom 66. The second core 6 mainly forms a part of the mounting surface 8a side of the core 8 shown in FIG. 2.

[0039] The main body 60 has a bottomed cylindrical shape, and the external shape of the main body 60 is a substantially rectangular parallelepiped shape. The thickness of the main body 60 in the Z-axis direction is greater than the thickness of the core base portion 50 in the Z-axis direction shown in FIG. 3. The width of the main body 60 in the X-axis direction is substantially the same as the width of the core base portion 50 in the X-axis direction, and the width of the main body 60 in the Y-axis direction is substantially the same as the width of the core base portion 50 in the Y-axis direction. When the first core 5 is combined with the second core 6, the upper surface of the main body 60 (the surface opposite to the bottom portion 66) is connected to the surface (upper surface) of the core base portion 50 of the first core 5.

[0040] The accommodating hole 61 is formed in approximately the center of the main body 60, and extends from one surface (top surface) of the main body 60 in the Z-axis direction to the other surface (bottom 66). The shape of the opening of the accommodating hole 61 is approximately circular, and approximately matches the outer circumferential shape of the coil 2 shown in FIG. 5. The end of the accommodating hole 61 opposite the opening is closed by the bottom 66. The accommodating hole 61 accommodates the columnar portion 51 (FIG. 3) of the first core 5 with the coil 2 attached thereto.

[0041] The bottom portion 66 forms the lower surface of the main body portion 60. In a state in which the columnar portion 51 is accommodated inside the accommodation hole 61 (i.e., in a state in which the first core 5 and the second core 6 are combined), the bottom portion 66 forms the mounting surface 8a of the core 8 shown in Figures 1 and 2. That is, in Figure 4, the mounting portions 44a, 44b of the terminals 4a, 4b are arranged on the surface of the bottom portion 66 on the negative side in the Z-axis direction.

[0042] The second recess 64 is formed on each side surface in the X-axis direction of the main body 60. The connection parts 43a and 43b of the terminals 4a and 4b shown in FIG. 6 are arranged in each second recess 64. The depth of the second recess 64 along the X-axis direction is the same as the depth of the first recess 52 along the X-axis direction shown in FIG. 3. The width of the second recess 64 along the Y-axis direction is the same as the width of the first recess 52 along the Y-axis direction. In a state where the first core 5 and the second core 6 are combined, the second recess 64 is connected to the first recess 52 along the Z-axis direction. As a result, as shown in FIG. 1, a lateral recess 80 is formed on each side surface in the X-axis direction of the core 8 so as to extend from one end to the other end in the Z-axis direction.

[0043] 9C, the third recess 65 is formed on the surface (outer surface) of the bottom 66. Two third recesses 65 are formed in the bottom 66, and each third recess 65 is formed continuously with each second recess 64 formed on each side surface in the X-axis direction of the main body 60. The third recess 65 and the second recess 64 intersect at right angles at a corner of the main body 60, and the third recess 65 extends from the end of the second recess 64 in the Z-axis direction toward the center of the bottom 66.

[0044] 4, the terminal accommodating grooves 62a, 62b are formed in corners of the main body 60. The terminal accommodating groove 62a is formed in a corner formed at a position where the surface of the main body 60 on the Y-axis positive side intersects with the surface on the X-axis positive side, and the terminal accommodating groove 62b is formed in a corner formed at a position where the surface of the main body 60 on the Y-axis positive side intersects with the surface on the X-axis negative side.

[0045] The terminal accommodating grooves 62a, 62b extend from one surface (top surface) of the main body 60 in the Z-axis direction to the other surface (bottom 66). The openings of the terminal accommodating grooves 62a, 62b are substantially rectangular in shape. When the first core 5 and the second core 6 are combined as shown in FIG. 3, the terminal accommodating groove 62a can accommodate the connection portion 42a of the terminal 4a shown in FIG. 2. The terminal accommodating groove 62a accommodates the connection portion 42a in a state in which the drawn-out portion 3a of the wire 3 is connected by the molten material 9, and a space large enough to accommodate the molten material 9 is formed inside the terminal accommodating groove 62a.

[0046] In addition, in a state in which the first core 5 and the second core 6 shown in Fig. 3 are combined, the inside of the terminal accommodating groove 62b is capable of accommodating the connection portion 42b of the terminal 4b shown in Fig. 2. The terminal accommodating groove 62b accommodates the connection portion 42b in a state in which the drawn-out portion 3b of the wire 3 is connected by the molten material 9, and a space large enough to accommodate the molten material 9 is formed inside the terminal accommodating groove 62b.

[0047] The width in the X-axis direction of the terminal accommodating grooves 62a, 62b is larger than the width in the X-axis direction of the connecting wire parts 42a, 42b shown in Fig. 2. The width in the Y-axis direction of the terminal accommodating grooves 62a, 62b is larger than the width in the Y-axis direction of the molten material 9 attached to the connecting wire parts 42a, 42b shown in Fig. 2. The depth in the Z-axis direction of the terminal accommodating grooves 62a, 62b is large enough to accommodate the entire connecting wire parts 42a, 42b of the terminals 4a, 4b, and is larger than at least the length in the Z-axis direction of the connecting wire parts 42a, 42b. As shown in Fig. 2, the length in the Z-axis direction of the connecting wire part 42a is longer than the length in the Z-axis direction of the connecting wire part 42b, and correspondingly, the length in the Z-axis direction of the terminal accommodating groove 62a may be longer than the length in the Z-axis direction of the terminal accommodating groove 62b.

[0048] The connecting grooves 63a and 63b extend from one surface (top surface) of the main body 60 in the Z-axis direction to the other surface (bottom 66). The connecting grooves 63a and 63b extend along the Y-axis direction and connect the accommodating hole 61 to the terminal accommodating grooves 62a and 62b. The connecting groove 63a is connected to the end of the accommodating hole 62 on the positive side of the X-axis, and the connecting groove 63b is connected to the end of the accommodating hole 62 on the negative side of the X-axis.

[0049] In a state where the first core 5 and the second core 6 shown in FIG. 3 are combined, the inside of the connecting groove 63a houses the lead-out portion 3a of the wire 3 shown in FIG. 2, and the inside of the connecting groove 63b houses the lead-out portion 3b of the wire 3. The width of the connecting groove 63a in the X-axis direction is larger than the width of the lead-out portion 3a, and the width of the connecting groove 63b in the X-axis direction is larger than the width of the lead-out portion 3b. The depth of the connecting grooves 63a and 63b along the Z-axis direction is large enough to accommodate the entire lead-out portions 3a and 3b. As shown in FIG. 2, the length of the lead-out portion 3a in the Z-axis direction is larger than the length of the lead-out portion 3b in the Z-axis direction, and correspondingly, the length of the connecting groove 63a along the Z-axis direction may be longer than the length of the connecting groove 63b along the Z-axis direction.

[0050] As shown in FIG. 5, the coil 2 is a flatwise coil. The coil 2 is formed by α-winding the wire 3 made of a rectangular wire, and is composed of two layers along the Z-axis direction. The winding axis direction of the coil 2 corresponds to the Z-axis direction. The wire 3 is wound so that two relatively wide faces of the four side faces constituting the outer surface of the rectangular wire face the inner and outer periphery of the coil 2. The coil 2 may be an edgewise coil formed by winding so that two relatively narrow faces of the four side faces constituting the outer surface of the rectangular wire face the inner and outer periphery of the coil 2.

[0051] Coil 2 is an air-core coil, and during manufacture of inductor 1, coil 2 is attached to first core 5 such that columnar portion 51 of first core 5 shown in Fig. 3 passes through the inside of coil 2. After second core 6 is assembled to first core 5 and compressed, coil 2 is embedded inside core 8 as shown in Fig. 2.

[0052] Materials constituting the wire 3 include, for example, good conductors such as copper, copper alloys, silver, and nickel, but are not particularly limited as long as they are conductive materials. The wire 3 is made of an insulating-coated wire, and an insulating coating is applied to the surface of the wire 3. The resin constituting the insulating coating is not particularly limited, but for example, polyamide-imide resin or urethane resin is used. Furthermore, the wire 3 may be a self-bonding wire having a fusion coating on the outside of the insulating coating. The resin constituting the fusion coating is not particularly limited, but for example, polyamide resin or epoxy resin is used.

[0053] As shown in Fig. 5, the lead-out portion 3a of the wire 3 is drawn out from the first lead-out position 2c of the coil 2 in the second layer (second stage) of the coil 2 and extends linearly along the Y-axis direction. The lead-out portion 3b of the wire 3 is drawn out from the second lead-out position 2d of the coil 2 in the first layer (first stage) of the coil 2 and extends linearly along the Y-axis direction. The lead-out portions 3a and 3b are drawn out in the same direction (Y-axis direction) without being twisted. The first lead-out position 2c and the second lead-out position 2d are misaligned along the Z-axis direction, and the lead-out portions 3a and 3b are arranged with a misalignment along the Z-axis direction.

[0054] The lead-out portions 3a and 3b of the wire 3 are connected to the connection portions 42a and 42b of the terminals 4a and 4b shown in Fig. 2. Note that, in the state shown in Fig. 5, the lead-out portions 3a and 3b are led out along the Y-axis direction, but when connected to the connection portions 42a and 42b, they extend in a direction inclined inward with respect to the Y-axis direction.

[0055] 6, the terminal 4a has a base portion 41a, a connecting portion 42a, a connection portion 43a, and a mounting portion 44a. The terminal 4b has a base portion 41b, a connecting portion 42b, a connection portion 43b, and a mounting portion 44b. The terminals 4a and 4b are formed by machining a conductive plate material such as a metal, but the method of forming the terminals 4a and 4b is not limited to this.

[0056] The base portions 41a and 41b have a flat plate shape extending in a direction (i.e., the X-axis direction and the Y-axis direction) substantially perpendicular to the winding axis direction of the coil 2. The base portions 41a and 41b have inner edge portions 41a1 and 41b1, side edge portions 41a2 and 41b2, and outer edge portions 41a3 and 41b3. The inner edge portions 41a1 and 41b1 are inner edges of the base portions 41a and 41b in the X-axis direction and extend linearly along the Y-axis direction. The inner edge portion 41a1 and the inner edge portion 41b1 are disposed opposite to each other.

[0057] The side edges 41a2, 41b2 are edges of the base portions 41a, 41b in the Y-axis direction, and are located on the opposite side of the connecting wire portions 42a, 42b along the Y-axis direction. The side edges 41a2, 41b2 extend linearly along the X-axis direction. The side edges 41a2, 41b2 are located outside the Y-axis direction of the ends of the connecting portions 43a, 43b on the negative Y-axis side.

[0058] The outer edges 41a3, 41b3 are outer edges of the base portions 41a, 41b in the X-axis direction, and face the side where the side surface of the core 8 is located. The outer edges 41a3, 41b3 extend approximately parallel to the inner edges 41a1, 41b1.

[0059] The base portions 41a and 41b are disposed inside the core 8 shown in Fig. 2. The base portions 41a and 41b have a substantially rectangular shape when viewed from the Z-axis direction. When manufacturing the inductor 1, the base portions 41a and 41b are placed on the step portions 500 of the core base portion 50 of the first core 5 shown in Fig. 3 at a predetermined interval along the X-axis direction. The interval between the base portions 41a and 41b corresponds to the distance between the step portions 500 along the X-axis direction, i.e., the width of the step upper portion 501 in the X-axis direction.

[0060] Since the base portions 41a, 41b are positioned on the surface of the step portion 500, when the first core 5 is combined with the second core 6 shown in Figure 4 (i.e., when the core 8 shown in Figure 2 is formed), the base portions 41a, 41b are positioned at a position spaced apart from the anti-mounting surface 8b of the core 8 in the Z-axis direction by the thickness of the step portion 500.

[0061] The ratio H / T2 of the height H in the Z-axis direction of the base portions 41a, 41b from the anti-mounting surface 8b of the core 8 to the thickness T2 in the Z-axis direction of the core 8 is preferably 1 / 15 to 1 / 2, and more preferably 1 / 8 to 1 / 3. By setting the value of H / T2 in this range, a suitable thickness is provided in a portion of the core 8 located between the base portions 41a, 41b and the anti-mounting surface 8b of the core 8, and defects such as the occurrence of cracks in that portion can be prevented.

[0062] As shown in Fig. 2, the coil 2 is placed on the upper surfaces of the base parts 41a and 41b. More specifically, a second end 2b of the coil 2 in the winding axis direction is provided on the upper surfaces of the base parts 41a and 41b, and the second end 2b is in contact with the base parts 41a and 41b. When the non-mounting surface 8b is used as a reference, the position in the Z-axis direction of the second end 2b of the coil 2 is located higher in the Z-axis direction than the position in the Z-axis direction of the bottom surfaces of the base parts 41a and 41b by the thickness of the base parts 41a and 41b, and a step is formed between the second end 2b of the coil 2 and the bottom surfaces of the base parts 41a and 41b.

[0063] 8, in a state where the second end 2b of the coil 2 is placed on the base portions 41a and 41b, the inner edge portions 41a1 and 41b1 of the base portions 41a and 41b are located between the outer peripheral surface and the inner peripheral surface of the coil 2. With this configuration, the second end 2b of the coil 2 can be stably placed on the base portions 41a and 41b. Also, since the inner edge portions 41a1 and 41b1 of the base portions 41a and 41b are not placed in the path of the magnetic flux passing through the inner peripheral side of the coil 2, the path of the magnetic flux is well secured, and the inductor 1 having good inductance characteristics can be realized.

[0064] In order to enable the above-mentioned arrangement, the relationship between the distance L1 in the X-axis direction between the base portion 41a and the base portion 41b, the inner diameter R1 of the coil 2, and the outer diameter R2 of the coil 2 is preferably R1≦L1 <R2である。

[0065] As shown in the figure, when the distance L1 in the X-axis direction between base portion 41a and base portion 41b and the inner diameter R1 of coil 2 are approximately equal, it is possible to ensure a sufficient contact area between the second end 2b of coil 2 and base portions 41a, 41b, and coil 2 can be placed on base portions 41a, 41b in a more stable state.

[0066] Also, from the perspective of placing the coil 2 stably on the base portions 41a and 41b, regarding the X-axis direction width L2 of the base portions 41a and 41b, preferably L2 ≧ (R2 - R1) / 4, more preferably L2 ≧ (R2 - R1) / 2, and particularly preferably L2 ≧ (R2 - R1) / 2 and R1 ≦ L1 < R2. In this case, when the coil 2 is placed on the base portions 41a and 41b, it is possible to prevent the outer peripheral surface of the coil 2 from protruding outside the outer edge portions 41a3 and 41b3 or the side edge portions 41a2 and 41b2 of the base portions 41a and 41b, and the base portions 41a and 41b can support the second end portion 2b of the coil 2 with sufficient supporting force.

[0067] In a state where the coil 2 is placed on the base portions 41a and 41b, the outer peripheral surface of the coil 2 is disposed inside the virtual line VL1 that connects the side edge portion 41a2 of the base portion 41a and the side edge portion 41b2 of the base portion 41b in the X-axis direction in the Y-axis direction. By placing the coil 2 on the base portions 41a and 41b so that the outer peripheral surface of the coil 2 is not disposed outside the virtual line VL1 in the Y-axis direction, it is possible to dispose the outer peripheral surface of the coil 2 at a position sufficiently separated from the side surface on the negative Y-axis side of the core 8. Between the outer peripheral surface of the coil 2 (the end portion on the negative Y-axis side of the coil 2) and the side surface on the negative Y-axis side of the core 8, the thickness of the core 8 can be sufficiently ensured, and it is possible to prevent cracks from occurring on the side surface on the negative Y-axis side of the core 8. The ratio L4 / L5 of the length L4 between the side edge portions 41a2 and 41b2 and the side surface on the negative Y-axis side of the core 8 to the Y-axis direction width L5 of the core 8 is preferably 1 / 32 to 1 / 6, and more preferably 1 / 20 to 1 / 10.

[0068] Also, from the perspective of placing the coil 2 stably on the base portions 41a and 41b, regarding the length L3 along the Y-axis direction of the base portions 41a and 41b, preferably L3 ≧ R2 / 2, and more preferably L3 ≧ R2. Also, the length L3 along the Y-axis direction of the base portions 41a and 41b is preferably larger than the length along the Y-axis direction of the connection portions 43a and 43b.

[0069] When L3≧R2 is satisfied, it is possible to prevent the outer circumferential surface of the coil 2 from protruding outside the side edge portions 41a2, 41b2 of the base portions 41a, 41b or the connection portions 42a, 42b, particularly in the Y-axis direction. Also, in the Y-axis direction, it is possible to dispose the region of the coil 2 from one end to the other end in the Y-axis direction inside the base portions 41a, 41b, and the coil 2 can be stably placed on the base portions 41a, 41b.

[0070] The width L2 in the X-axis direction of the base portions 41a, 41b is approximately constant along the Y-axis direction, and for example, no recess or other shape is provided to the inner edge portions 41a1, 41b1 of the base portions 41a, 41b. The base portions 41a, 41b extend continuously from the positions of the side edge portions 41a2, 41b2 to the positions of the ends on the Y-axis positive side to which the connecting wire portions 42a, 42b are connected.

[0071] 7B, a part of the lead-out portion 3b of the wire 3 is placed on the upper surface of the base portion 41b together with the second end 2b of the coil 2. More specifically, the lead-out bottom portion 3b1 of the lead-out portion 3b is placed on the upper surface of the base portion 41b, and the lead-out bottom portion 3b1 and the base portion 41b are in contact with each other. As a result, the lead-out bottom portion 3b1 of the lead-out portion 3b is supported by the base portion 41b1.

[0072] In this embodiment, the lead-out portion 3b of the wire 3 is drawn out from below the coil 2 (second lead-out position 2d shown in FIG. 5), so that when the second end 2b of the coil 2 is placed on the base portion 41b, the lead-out portion 3b is drawn outward in the Y-axis direction with the lead-out bottom portion 3b1 disposed along the upper surface of the base portion 41b. On the other hand, the lead-out portion 3a of the wire 3 is drawn out from above the coil 2 (first lead-out position 2c shown in FIG. 5), so that it is not placed on the upper surface of the base portion 41a but is disposed at a position spaced a predetermined distance from the upper surface of the base portion 41a.

[0073] The connection parts 42a, 42b are connected to the lead-out parts 3a, 3b of the wire 3. As shown in Fig. 2, the connection parts 42a, 42b are disposed inside the core 8. In this embodiment, the lead-out parts 3a, 3b are extended in substantially the same direction (the positive Y-axis direction) and therefore the connection parts 42a, 42b are disposed on the positive Y-axis side of the coil 2 from which the lead-out parts 3a, 3b are extended.

[0074] As shown in FIG. 6, the connecting wire parts 42a and 42b are raised from the base parts 41a and 41b along the Z-axis direction. More specifically, the connecting wire parts 42a and 42b are raised from the ends of the base parts 41a and 41b on the Y-axis positive side (ends located opposite to the side edges 41a2 and 41b2) in a state of being approximately perpendicular to the base parts 41a and 41b, and extend along the Z-axis direction. The rising positions of the connecting wire parts 42a and 42b are located outside the Y-axis direction from the ends of the connecting parts 43a and 43b on the Y-axis positive side. As shown in FIG. 2, the ends of the base parts 41a and 41b on the Y-axis positive side are disposed outside the ends of the coil 2 in the Y-axis direction, so that the rising positions of the connecting wire parts 42a and 42b are disposed outside the ends of the coil 2 in the Y-axis direction.

[0075] As shown in Fig. 7B, the first connection portion 42a and the second connection portion 42b extend along the Z-axis direction so as to be substantially parallel to each other at different positions in the X-axis direction. As shown in Fig. 6, the length L6 of the first connection portion 42a along the Z-axis direction is longer than the length L7 of the second connection portion 42b along the Z-axis direction. The ratio L7 / L6 of the length L7 of the second connection portion 42b along the Z-axis direction to the length L6 of the first connection portion 42a along the Z-axis direction is preferably 1 / 4≦L7 / L6<1, and more preferably 1 / 3≦L7 / L6<2 / 3.

[0076] 8, in a state where the coil 2 is placed on the base portions 41a and 41b, the outer circumferential surface of the coil 2 is not exposed outside in the Y-axis direction from the imaginary line VL2 connecting the first connection portion 42a and the second connection portion 42b in the X-axis direction, and is disposed inside in the Y-axis direction from the imaginary line VL2. With this configuration, the outer circumferential surface of the coil 2 can be disposed at a position sufficiently separated from the side surface of the core 8 on the Y-axis positive side, and the thickness of the core 8 can be sufficiently secured between the outer circumferential surface of the coil 2 (the end portion of the coil 2 on the Y-axis positive side) and the side surface of the core 8 on the Y-axis positive side, thereby preventing cracks from occurring on the side surface of the core 8 on the Y-axis positive side.

[0077] The length L8 along the Y-axis direction between the connecting wire portions 42a, 42b and the side surface of the core 8 on the positive side of the Y-axis is greater than the length L4 between the side edge portions 41a2, 41b2 of the base portions 41a, 41b and the side surface of the core 8 on the negative side of the Y-axis. As described above, this is because in this embodiment, the center of the coil 2 is shifted toward the negative side of the Y-axis with respect to the center of the core 8. The ratio L8 / L5 of the length L8 along the Y-axis direction between the connecting wire portions 42a, 42b and the side surface of the core 8 on the positive side of the Y-axis to the width L5 of the core 8 in the Y-axis direction is preferably 1 / 16 to 1 / 4, and more preferably 1 / 8 to 1 / 5.

[0078] 6, the connecting wire part 42a has a flat plate part 420, an accommodating recess 421a, and a pair of protruding parts 422a, 422a. The connecting wire part 42b has an accommodating recess 421b and a pair of protruding parts 422b, 422b.

[0079] The flat plate portion 420 has a flat plate shape parallel to the XZ plane and extends along the Z-axis direction in a state substantially perpendicular to the base portion 41a. The flat plate portion 420 serves to connect the base portion 41a and the pair of protruding portions 422a, 422a, and by providing the flat plate portion 420 to the connecting wire portion 42a, it is possible to shift the position of the accommodating recess 421a in the Z-axis direction upward from the position of the base portion 41a. That is, the flat plate portion 420 is provided mainly for the convenience of adjusting the height of the accommodating recess 421a.

[0080] The flat plate portion 420 is provided only at the wire connecting portion 42a and not at the wire connecting portion 42b. Therefore, the position of the tip portion of the wire connecting portion 42a in the Z-axis direction and the position of the tip portion of the wire connecting portion 42b in the Z-axis direction are displaced along the Z-axis direction by a distance corresponding to the height of the flat plate portion 420, and a step is formed along the Z-axis direction between the respective tip portions. Note that the height of the step corresponds to the difference between the length L6 of the wire connecting portion 42a along the Z-axis direction and the length L7 of the wire connecting portion 42b along the Z-axis direction.

[0081] As shown in FIG. 7B, the lead-out portion 3a of the wire 3 is accommodated in the accommodation recess 421a. The position (height in the Z-axis direction) of the accommodation recess 421a corresponds to the position (height in the Z-axis direction) of the first lead-out position 2c (FIG. 5) of the lead-out portion 3a, and the accommodation bottom portion 421a1 of the accommodation recess 421a is located at a position corresponding to the substantially central portion of the coil 2 in the Z-axis direction.

[0082] The accommodation recess 421a is formed by a notch formed along the Z-axis direction at the top of the wire connecting portion 42a. One end (upper end) of the accommodation recess 421a in the Z-axis direction is open, and the lead-out portion 3a of the wire 3 can be inserted (or slid) into the accommodation recess 421a from this open portion. As shown in FIG. 7A, the depth D2 of the accommodation recess 421a in the Z-axis direction is determined based on, for example, the height L9 of the lead-out portion 3a, and the ratio D2 / L9 of the depth D2 to the height L9 is preferably 1 < D2 / L9 ≤ 1.5, and more preferably 1 < D2 / L9 ≤ 1.3.

[0083] When the ratio D2 / L9 is set within the above range, a gap G1 can be formed between the lead-out bottom 3a1 of the lead-out portion 3a and the accommodation bottom 421a1 of the accommodation recess 421a when the lead-out portion 3a of the wire 3 is accommodated in the accommodation recess 421a. In this case, the lead-out portion 3a of the wire 3 accommodated in the accommodation recess 421a is located above the accommodation bottom 421a1 of the accommodation recess 421a by a distance corresponding to the length GL1 of the gap G1 in the Z-axis direction. The ratio GL1 / D2 of the length GL1 of the gap G1 to the depth D2 of the accommodation recess 421a is preferably 1 / 32 to 1 / 8, and more preferably 1 / 20 to 1 / 10.

[0084] With this configuration, even if the first pull-out position 2c (Figure 5) of the pull-out portion 3a is shifted in the Z-axis direction (particularly, downward in the Z-axis direction) due to a manufacturing error, the pull-out portion 3a can be accommodated in the accommodating recess 421a without bending the pull-out portion 3a, and the pull-out portion 3a can be connected to the connecting wire portion 42a in a linearly pulled-out state.

[0085] Furthermore, by setting the depth D2 of the accommodating recess 421a to be relatively deep in advance so that a gap (margin) G1 is formed between the pulled-out portion 3a and the accommodating bottom portion 421a1 of the accommodating recess 421a, the pulled-out portion 3a can be reliably accommodated in the accommodating recess 421a without tilting the coil 2. Furthermore, even if a situation arises in which the first pulled-out position 2c (FIG. 5) of the pulled-out portion 3a is positioned at a different position from normal along the Z-axis direction due to a design change, for example, the pulled-out portion 3a can be reliably accommodated in the accommodating recess 421a.

[0086] A gap G2 is formed between the end of the lead-out portion 3a on the side opposite to the lead-out bottom 3a1 and the top of the connection line portion 42a in the Z-axis direction. The length GL2 of the gap G2 in the Z-axis direction is larger than the length GL1 of the gap G1 in the Z-axis direction, but it may also be smaller than this. By providing the gap G2 in the accommodation recess 421a in this way, even if, for example, due to manufacturing errors, the first lead-out position 2c (FIG. 5) of the lead-out portion 3a is displaced in the Z-axis direction (particularly, above the Z-axis), as described above, the lead-out portion 3a can be connected to the connection line portion 42a in a state where the lead-out portion 3a is linearly pulled out without performing bending processing on the lead-out portion 3a. Also, it becomes possible to prevent the lead-out portion 3a from protruding outside the accommodation recess 421a, and as will be described later, laser welding can be easily performed on the joint portion between the connection line portion 42a and the lead-out portion 3a. Note that the gaps G1 and G2 are not essential and may be omitted.

[0087] Also, the depth D2 of the accommodation recess 421a in the Z-axis direction may be determined based on, for example, the length L6 of the connection line portion 42a shown in FIG. 6. The ratio D2 / L6 of the depth D2 to the height L6 is preferably 1 / 4 < D2 / L6 ≦ 3 / 4, and more preferably 3 / 8 < D2 / L6 ≦ 5 / 8. By setting the ratio D2 / L6 within the above range, the lead-out portion 3a can be accommodated inside the accommodation recess 421a so that a part of the lead-out portion 3a does not protrude outside the upper end portion of the accommodation recess 421a.

[0088] A pair of protruding portions 422a, 422a are formed with the accommodation recess 421a interposed therebetween. The extending direction of the protruding portions 422a, 422a is the same as the extending direction of the flat plate portion 420, which is the Z-axis direction. The length of the protruding portions 422a, 422a along the Z-axis direction corresponds to the length D2 of the accommodation recess 421a along the Z-axis direction.

[0089] The distance in the X-axis direction between one protruding portion 422a and the other protruding portion 422a (i.e., the width of the accommodating recess 421a in the X-axis direction) is larger than the plate thickness of the lead-out portion 3a of the wire 3. This is to make it easier to insert the lead-out portion 3a into the accommodating recess 421a. The lead-out portion 3a is fixed in the accommodating recess 421a so as to be sandwiched between the protruding portions 422a, 422a.

[0090] As shown in Fig. 7B, the accommodating recess 421b accommodates the pull-out portion 3b of the wire 3. The position (height in the Z-axis direction) of the accommodating recess 421b corresponds to the position (height in the Z-axis direction) of the second pull-out position 2d (Fig. 5) of the pull-out portion 3b.

[0091] The accommodating recess 421b is a notch formed in the top of the connecting wire portion 42b along the Z-axis direction. However, a part (bottom) of the accommodating recess 421b is embedded in the end of the base portion 41b on the Y-axis positive side, and strictly speaking, a part of the accommodating recess 421b is formed in the base portion 41b along the Y-axis direction. By forming the accommodating recess 421b to extend to the base portion 41b in this manner, it becomes easy to bend (rise up) a pair of protruding portions 422b, 422b, which will be described later, in the Z-axis direction at the intersection between the base portion 41b and the connecting wire portion 42b.

[0092] One end (upper end) in the Z-axis direction of the accommodating recess 421b is open, and the lead-out portion 3b of the wire 3 can be inserted (or slid) into the inside of the accommodating recess 421b from this open portion. As shown in FIG. 7A, when the lead-out portion 3a is accommodated in the accommodating recess 421a, a gap G1 is formed between the lead-out bottom portion 3a1 of the lead-out portion 3a and the accommodating bottom portion 421a1 of the accommodating recess 421a, but when the lead-out portion 3b is accommodated in the accommodating recess 421b, such a gap is not formed. Therefore, when the lead-out portion 3b is accommodated in the accommodating recess 421b, the lead-out bottom portion 3b1 of the lead-out portion 3b is placed on the upper surface of the base portion 41b, and the lead-out bottom portion 3b1 and the upper surface of the base portion 41b are in contact with each other.

[0093] A gap G2 is formed between the end of the lead-out portion 3b on the side opposite to the lead-out bottom 3b1 and the top of the connection line portion 42b in the Z-axis direction, similar to the case of the accommodation recess 421a.

[0094] The depth D3 of the accommodation recess 421b in the Z-axis direction may be determined based on the height L9 of the lead-out portion 3b, similar to the depth D2 of the accommodation recess 421a in the Z-axis direction. In this case, the ratio D3 / L9 of the depth D3 to the height L9 is preferably 1 < D3 / L9 ≤ 1.5, and more preferably 1 < D3 / L9 ≤ 1.3. Note that the depth D3 of the accommodation recess 421b in the Z-axis direction defined here is the depth of the portion where the lead-out portion 3b can actually be arranged in the accommodation recess 421b, and corresponds to the depth from the top of the connection line portion 42b in the Z-axis direction to the upper surface of the base portion 41b. The depth D3 of the accommodation recess 421b in the Z-axis direction is substantially equal to the depth D2 of the accommodation recess 421a in the Z-axis direction.

[0095] The depth D3 of the accommodation recess 421b in the Z-axis direction may be determined based on the length L7 of the connection line portion 42b shown in FIG. 6. The ratio D3 / L7 of the depth D3 to the height L7 is preferably 1 / 2 < D3 / L7 < 1, and more preferably 5 / 8 < D3 / L7 ≤ 7 / 8. By setting the ratio D3 / L7 within the above range, the lead-out portion 3b can be accommodated inside the accommodation recess 421b so that a part of the lead-out portion 3b does not protrude outward from the upper end of the accommodation recess 421b.

[0096] A pair of protruding portions 422b, 422b are formed with the accommodation recess 421b interposed therebetween. The extending direction of the protruding portions 422b, 422b is the same as that of the protruding portions 422a, 422a, which is the Z-axis direction. The length of the protruding portions 422b, 422b along the Z-axis direction corresponds to the length L7 (FIG. 6) of the connection line portion 42b along the Z-axis direction.

[0097] The distance in the X-axis direction between one protruding portion 422b and the other protruding portion 422b (i.e., the width of the accommodating recess 421b in the X-axis direction) is larger than the plate thickness of the lead-out portion 3b of the wire 3. This is to make it easier to insert the lead-out portion 3b into the accommodating recess 421b. The lead-out portion 3b is fixed in the accommodating recess 421b so as to be sandwiched between the protruding portions 422b, 422b.

[0098] 7A, the accommodating recess 421a and the accommodating recess 421b are misaligned in the Z-axis direction. Also, the position of the pull-out portion 3a accommodated in the accommodating recess 421a is misaligned in the Z-axis direction from the position of the pull-out portion 3b accommodated in the accommodating recess 421b.

[0099] In this embodiment, the lead-out portion 3a and the lead-out portion 3b are led out from the coil 2 in a state of being misaligned along the Z-axis direction, and accordingly, the connection wire portions 42a and 42b are formed so that the accommodating recess 421a and the accommodating recess 421b are misaligned along the Z-axis direction. The misalignment width along the Z-axis direction between the accommodating recess 421a and the accommodating recess 421b corresponds to the distance along the Z-axis direction between the lead-out position 2c (FIG. 5) of the lead-out portion 3a and the lead-out position 2d (FIG. 5) of the lead-out portion 3b. The misalignment width along the Z-axis direction between the accommodating recess 421a and the accommodating recess 421b may correspond to the width along the Z-axis direction of the wire 3 (lead-out portions 3a and 3b).

[0100] The misalignment width between the accommodating recess 421a and the accommodating recess 421b in the Z-axis direction may correspond to the distance between the tip of the pair of protruding portions 422a, 422a and the tip of the pair of protruding portions 422b, 422b. The misalignment width between the accommodating recess 421a and the accommodating recess 421b in the Z-axis direction may correspond to the distance between the accommodating bottom portion 421a1 of the accommodating recess 421a and the upper surface of the base portion 41b. The misalignment width between the accommodating recess 421a and the accommodating recess 421b in the Z-axis direction may correspond to the length of the flat plate portion 420 of the connecting wire portion 42a in the Z-axis direction.

[0101] When the connecting wire parts 42a and 42b are viewed from the front (Y-axis positive side), as shown in Figs. 7A and 8, the accommodating recesses 421a and 421b are disposed inward from the outer periphery of the coil 2 in the X-axis direction. That is, the distance L10 between the accommodating recesses 421a and 421b is smaller than the outer diameter R2 of the coil 2. The distance L10 is also smaller than the distance between the first extracting position 2c (Fig. 5) of the extracting part 3a of the wire 3 and the second extracting position 2d (Fig. 5) of the extracting part 3b, and the accommodating recesses 421a and 421b are disposed between the first extracting position 2c and the second extracting position 2d. Therefore, as shown in Fig. 8, the extracting parts 3a and 3b are accommodated in the accommodating recesses 421a and 421b in a state in which they are extracted while inclined inward by a predetermined angle with respect to the Y-axis direction.

[0102] 7A, the pull-out portion 3a contacts only the protruding portion 422a, which is located on the outer side in the X-axis direction (the negative side of the X-axis) of the pair of protruding portions 422a, 422a due to its elastic force, and the pull-out portion 3b contacts only the protruding portion 422b, which is located on the outer side in the X-axis direction (the positive side of the X-axis) of the pair of protruding portions 422b, 422b due to its elastic force.

[0103] With the lead-out portions 3a, 3b of the wire 3 housed in the housing recesses 421a, 421b, the connecting portions 42a, 42b are irradiated with a laser, and as shown in FIG. 2, a molten material (joint or joint member) 9 consisting of welding beads or the like is formed on the connecting portions 42a, 42b. As a result, the pair of protruding portions 422a, 422a shown in FIG. 6 are connected with the molten material 9, and the pair of protruding portions 422b, 422b are connected with the molten material 9. The connecting portions 42a, 42b are irradiated with a laser from a direction inclined at a predetermined angle with respect to the Y-axis direction, so that the laser is irradiated on the wide surfaces of the lead-out portions 3a, 3b. The molten material 9 is formed mainly on the surfaces (laser irradiated surfaces) of the connecting portions 42a, 42b on the Y-axis positive side.

[0104] As shown in Fig. 6, the connection parts 43a, 43b are raised along the Z-axis direction at positions on the base parts 41a, 41b that are different from the connection parts 42a, 42b. The connection parts 43a, 43b are raised from outer edges 41a3, 41b3 on the opposite side of the X-axis direction from the inner edges 41a1, 41b1 of the base parts 41a, 41b, and are formed closer to the connection parts 42a, 42b in the Y-axis direction than the side edges 41a2, 41b2 of the base parts 41a, 41b. The connection parts 43a, 43b connect the base parts 41a, 41b and the mounting parts 44a, 44b.

[0105] The connection parts 43a and 43b have mounting auxiliary parts 430a and 430b and side lead parts 431a and 431b. The side lead parts 431a and 431b are connected to outer edge parts 41a3 and 41b3 of the base parts 41a and 41b. The side lead parts 431a and 431b have surfaces parallel to the XY plane and extend outward in the X-axis direction to positions of each side surface of the core 8 in the X-axis direction.

[0106] The mounting auxiliary parts 430a, 430b are connected to the ends of the side lead parts 431a, 431b in the X-axis direction and extend upward. The mounting auxiliary parts 430a, 430b have surfaces parallel to the YZ plane and extend along each side surface of the core 8 in the X-axis direction to the position of the mounting surface 8a of the core 8. The side lead parts 431a, 431b are embedded inside the core 8, while the mounting auxiliary parts 430a, 430b are exposed to the outside of the core 8.

[0107] The mounting portions 44a, 44b are connected to the ends of the mounting auxiliary portions 430a, 430b in the Z-axis direction, and extend inward in the X-axis direction. The mounting portions 44a, 44b have surfaces parallel to the XY plane, and are formed along the mounting surface 8a of the core 8 shown in Fig. 2. The mounting portions 44a, 44b are exposed to the outside of the core 8 at the mounting surface 8a, and form a connection portion with a circuit board or the like (not shown) when the inductor 1 is mounted.

[0108] The mounting portions 44a, 44b are connected to a circuit board or the like via a connecting member such as solder, a conductive adhesive, etc. At that time, it is possible to form a solder fillet on the mounting assistance portions 430a, 430b, which can increase the mounting strength of the inductor 1 to the circuit board or the like.

[0109] Next, a method for manufacturing the inductor 1 will be described with reference to Figs. 9A to 9E. In the method of this embodiment, first, a conductive plate such as a metal plate (for example, a Sn-plated metal plate) is punched into a shape as shown in Fig. 9A or 9C. As shown in the figure, terminals 4a and 4b connected to the frame 7 via connecting parts 43a and 43b are formed on the conductive plate after punching. On the frame 7, the terminals 4a and 4b are arranged at a predetermined interval along the X-axis direction, and the interval corresponds to the distance L1 shown in Fig. 8.

[0110] Next, as shown in FIG. 9A, the coil 2 is placed on the base portions 41a, 41b so that the second end portion 2b of the coil 2 is in contact with the base portions 41a, 41b, and the second end portion 2b of the coil 2 is positioned so as to straddle the base portions 41a, 41b which are arranged at a predetermined interval along the X-axis direction.

[0111] At this time, the lead-out portions 3a and 3b of the wire 3 are accommodated in the accommodation recesses 421a and 421b of the connection wire portions 42a and 42b and connected to the terminals 4a and 4b. The lead-out portions 3a and 3b can be accommodated, for example, by being inserted (sliding) downward from the upper end portions of the accommodation recesses 421a and 421b. The lead-out portion 3b of the wire 3 is placed on the base portion 41b so that the lead-out bottom portion 3b1 contacts the base portion 41b. After the lead-out portions 3a and 3b are accommodated in the accommodation recesses 421a and 421b, they may be temporarily fixed with an adhesive or the like.

[0112] 9B, a laser is irradiated onto the connecting portions 42a, 42b from a direction inclined at a predetermined angle with respect to the Y-axis direction, and a molten material 9 is formed on the connecting portions 42a, 42b. As a result, the pair of protruding portions 422a, 422a is connected by the molten material 9, and the pair of protruding portions 422b, 422b is connected by the molten material 9. Note that the range in which the molten material 9 is formed is not limited to the range shown in the figure, and may be changed as appropriate within a range in which the drawn-out portions 3a, 3b and the connecting portions 42a, 42b can be satisfactorily connected.

[0113] Next, the coil 2 with the terminals 4a, 4b fixed to each end is placed inside a mold, and as shown in Fig. 9C, the coil 2 is combined with the first core 5 shown in Fig. 3 and the first core 6 shown in Fig. 4 to form a temporary assembly shown in Fig. 9D. More specifically, the columnar portion 51 (Fig. 3) of the first core 5 is inserted inside the coil 2, and the coil 2 is placed on the stepped upper portion 501 of the core base portion 50. At the same time, the base portions 41a, 41b of the terminals 4a, 4b are placed on the stepped portions 500 of the core base portion 50.

[0114] The first core 5 and the second core 6 are assembled so that the connection parts 42a and 42b of the terminals 4a and 4b are accommodated in the terminal accommodating grooves 62a and 62b, the lead-out parts 3a and 3b of the wire 3 are accommodated in the connecting grooves 63a and 63b, and the columnar part 51 of the first core 5 and the coil 2 are accommodated in the accommodating hole 61 of the second core 6. The connecting parts 43a and 43b of the terminals 4a and 4b are exposed from the first core 5 and the second core 6. The first core 5 and the second core 6 are made of cores (temporarily molded cores) that have been molded in advance. The first core 5 and the second core 6 are made of a material with flowability, and a composite magnetic material using a thermoplastic resin or a thermosetting resin as a binder is used.

[0115] Next, the first core 5 and the second core 6 of the temporary assembly shown in Fig. 9D are compression molded using a die jig (upper and lower punches, etc.) to integrate them to form the core 8 (Fig. 9E). At this time, the first core 5 and the second core 6 can be easily integrated by applying heat.

[0116] Next, as shown in FIG. 9E, the frame 7 shown in FIG. 9D is cut and removed with a cutting tool so that only the connection parts 43a and 43b remain. Then, the connection parts 43a and 43b are fixed to the second recesses 64 and the third recesses 65. More specifically, as shown in FIG. 9F, the connection parts 43a and 43b of the terminals 4a and 4b are bent substantially vertically from the state shown in FIG. 9E, and the connection parts 43a and 43b are fixed to the second recesses 64. In addition, in this state, the tip parts of the connection parts 43a and 43b are bent substantially vertically and fixed to the third recesses 65. As a result, the mounting auxiliary parts 430a and 430b of the terminals 4a and 4b are formed in the second recess 64, and the mounting parts 44a and 44b of the terminals 4a and 4b are formed in the third recess 65. In this manner, the inductor 1 in this embodiment can be obtained.

[0117] In the inductor 1 according to this embodiment, as shown in Fig. 6 and Fig. 7B, accommodating recesses 421a, 421b for accommodating the lead-out portions 3a, 3b are formed in the connecting portions 42a, 42b. Therefore, by accommodating the lead-out portions 3a, 3b in the accommodating recesses 421a, 421b, the lead-out portions 3a, 3b can be connected to the connecting portions 42a, 42b, and it is not necessary to crimp the terminals 4a, 4b to the lead-out portions 3a, 3b when connecting the lead-out portions 3a, 3b to the connecting portions 42a, 42b, and the lead-out portions 3a, 3b can be easily connected to the terminals 4a, 4b.

[0118] In particular, in the inductor 1 according to this embodiment, the accommodating recess 421a and the accommodating recess 421b are misaligned along the Z-axis direction. Therefore, even if the first extracting position 2c (FIG. 5) of the extracting portion 3a and the second extracting position 2d (FIG. 5) of the extracting portion 3b are misaligned along the Z-axis direction, it is possible to extract the extracting portions 3a and 3b to the terminals 4a and 4b, respectively, without unnecessarily bending the extracting portion 3a or the extracting portion 3b. Therefore, in this respect as well, the extracting portions 3a and 3b can be easily connected to the terminals 4a and 4b.

[0119] Furthermore, in the inductor 1 of this embodiment, the connection wire portions 42a, 42b having the accommodating recesses 421a, 421b are arranged inside the core 8, and the coil 2 is made of a rectangular wire. Therefore, as described above, it is possible to easily manufacture a surface-mount type inductor 1 capable of passing a large current while easily connecting the lead-out portions 3a, 3b to the terminals 4a, 4b.

[0120] In the present embodiment, the length L6 of the connecting wire portion 42a along the Z-axis direction is longer than the length L7 of the connecting wire portion 42b along the Z-axis direction. Therefore, the accommodating recesses 421a and 421b can be disposed with a positional deviation along the Z-axis direction by a distance corresponding to the difference between the length L6 of the connecting wire portion 42a along the Z-axis direction and the length L7 of the connecting wire portion 42b along the Z-axis direction, and the above-mentioned effect can be obtained with a simple configuration.

[0121] In this embodiment, the bottom 3b1 of the drawn-out portion 3b accommodated in the accommodation recess 421b is in contact with the upper surface of the base portion 41b. Therefore, the base portion 41b supports the drawn-out portion 3b, and even if an external force acts on the drawn-out portion 3b, the drawn-out portion 3b is less likely to shift in position in the Z-axis direction. This makes it possible to determine the position of the drawn-out portion 3b at a predetermined position (the upper surface of the base portion 41b), and prevents variations in inductance characteristics, etc. from product to product due to variations in the position of the drawn-out portion 3b.

[0122] In the present embodiment, the accommodating recesses 421a, 421b are formed as notches formed in the connecting wire parts 42a, 42b along the Z-axis direction. Therefore, for example, by inserting the lead-out parts 3a, 3b from the tops of the connecting wire parts 42a, 42b into the accommodating recesses 421a, 421b along the Z-axis direction, the lead-out parts 3a, 3b can be easily accommodated in the accommodating recesses 421a, 421b.

[0123] In this embodiment, the pull-out portion 3a is arranged so as to be sandwiched between the pair of protruding portions 422a, 422a, so that the pull-out portion 3a can be stably accommodated in the accommodating recess 421a, and in this state, by joining the pair of protruding portions 422a, 422a with the molten material 9, the pull-out portion 3a can be effectively prevented from coming off from the accommodating recess 421a. Similarly, the pull-out portion 3b is arranged so as to be sandwiched between the pair of protruding portions 422b, 422b, so that the pull-out portion 3b can be stably accommodated in the accommodating recess 421b, and in this state, by joining the pair of protruding portions 422b, 422b with the molten material 9, the pull-out portion 3b can be effectively prevented from coming off from the accommodating recess 421b.

[0124] In this embodiment, as shown in Fig. 7B and Fig. 8, when the connection parts 42a, 42b are viewed from the Y-axis positive side, the accommodating recesses 421a, 421b are disposed inward from the outer periphery of the coil 2 in the X-axis direction. In order to accommodate the lead-out parts 3a, 3b in the accommodating recesses 421a, 421b in this state, the lead-out parts 3a, 3b need to be bent inward from the lead-out positions 2c, 2d (Fig. 5) toward the accommodating recesses 421a, 421b. This generates a biasing force on the lead-out parts 3a, 3b, and when the lead-out parts 3a, 3b are accommodated in the accommodating recesses 421a, 421b, the elastic force of the lead-out parts 3a, 3b allows the lead-out parts 3a, 3b to be fixed to the inside of the accommodating recesses 421a, 421b with sufficient fixing strength.

[0125] In this embodiment, the lead-out portions 3a, 3b are led out in substantially the same direction (the positive Y-axis direction), and the connection portions 42a, 42b are disposed on the positive Y-axis side of the coil 2 from which the lead-out portions 3a, 3b are led out. Therefore, when the connection portions 42a, 42b are laser-welded, for example, it is possible to irradiate the laser onto each of the connection portions 42a, 42b from substantially the same direction, which makes the laser welding easy and facilitates the manufacture.

[0126] The present invention is not limited to the above-described embodiment, and various modifications can be made within the scope of the present invention.

[0127] In the above embodiment, an example of application of the present invention to an inductor has been shown, but the present invention may be applied to coil devices other than inductors.

[0128] In the above embodiment, the wire 3 is made of a rectangular wire, but it may be made of a wire other than a rectangular wire, such as a round wire or a square wire.

[0129] In the above embodiment, the wire 3 is wound in a circular spiral shape, but it may be wound in an elliptical or angular spiral shape, for example.

[0130] In the above embodiment, the core 8 is composed of two cores, the first core 5 and the second core 6, but the core 8 of the inductor 1 may be composed of only one core. In this case, the core 8 may be formed by powder molding, injection molding, or the like inside a mold.

[0131] In the above embodiment, the connection parts 42a, 42b are disposed inside the core 8 as shown in FIG. 2, but they may be disposed so as to be exposed to the outside of the core 8. [Explanation of symbols]

[0132] 1...Inductor (coil device) 2. Coil 2a...first end 2b…Second end 2c…1st drawer position 2d…Second drawer position 3…Wire 3a,3b…Drawer part 3a1,3b1...Drawer bottom 4a, 4b...Terminals 41a, 41b...Base part 41a1,41b1...Inner edge 41a2,41b2...Side edge 41a3,41b3...outer edge 42a, 42b…Connection section 420...Flat plate part 421a, 421b...accommodating recess 421a1…Containment bottom 422a, 422b...Protruding part 43a, 43b...Connection 430a, 430b... Mounting assistance section 431a, 431b...Side drawer part 44a, 44b…Mounting section 5…First core 50…Core base part 500…Step 501…Top of the step 51...Columnar part 52…First recess 6…Second core 60…Main body 61...Housing hole 62a, 62b...Terminal receiving groove 63a, 63b…Connection groove 64…Second recess 65…3rd recess 66…bottom 7. Frame 8…Core 8a…Mounting surface 8b…Opposite mounting surface 80…Side recess 9…Melted material

Claims

1. A coil made of a rectangular wire; a first terminal including a first connecting portion having a first accommodating recess formed therein for accommodating a first lead portion of the coil; a second terminal including a second connection portion having a second accommodating recess formed therein for accommodating the second lead portion of the coil; the first accommodating recess and the second accommodating recess are misaligned along a winding axis direction of the coil, the first terminal has a first base portion from which the first connecting portion is raised along the winding axis direction, the second terminal has a second base portion from which the second connecting portion is raised along the winding axis direction, A coil device in which the second lead-out portion of the coil accommodated in the second accommodating recess is in contact with the second base portion.

2. A coil made of a rectangular wire; a first terminal including a first connecting portion having a first accommodating recess formed therein for accommodating a first lead portion of the coil; a second terminal including a second connection portion having a second accommodating recess formed therein for accommodating the second lead portion of the coil; the first accommodating recess and the second accommodating recess are misaligned along a winding axis direction of the coil, A coil device, wherein the first lead-out portion of the coil accommodated in the first accommodating recess is located above a bottom of the first accommodating recess.

3. the first connection portion and the second connection portion extend along the winding axis direction at different positions, The coil device according to claim 1 , wherein a length of the first connection portion along the winding axis direction is longer than a length of the second connection portion along the winding axis direction.

4. the first accommodating recess is a first notch formed in the first connecting portion along the winding axis direction, 4. The coil device according to claim 1, wherein the second accommodating recess is a second notch formed in the second connection portion along the winding axis direction.

5. The first connecting wire portion is formed with a pair of first protrusions sandwiching the first accommodating recess therebetween, The second connecting portion has a pair of second protruding portions formed thereon with the second accommodating recess therebetween, The pair of first protrusions are connected to each other at a joint, 5. The coil device according to claim 1, wherein the pair of second protrusions are connected to each other at a joint.

6. 6. The coil device according to claim 1, wherein when the first connection portion and the second connection portion are viewed from a direction in which the pull-out portion is pulled out, the first accommodating recess and the second accommodating recess are disposed inward from an outer periphery of the coil in a direction perpendicular to the winding axis direction.

7. the first drawn-out portion and the second drawn-out portion are drawn out in substantially the same direction as each other, 7. The coil device according to claim 1, wherein the first connection portion and the second connection portion are disposed on one side of the coil from which the first lead-out portion and the second lead-out portion are led out.

8. The body and A coil made of a rectangular wire and embedded inside the element body; a first terminal including a first connection portion to which a first lead portion of the coil is connected, the first connection portion being disposed inside the body; a second connection portion to which a second lead portion of the coil is connected, the second connection portion being disposed inside the body; and a second terminal, a first accommodating recess for accommodating the first drawn-out portion is formed in the first connecting portion; a second accommodating recess for accommodating the second lead-out portion is formed in the second connection portion, the first terminal has a first base portion from which the first connection portion is raised along a winding axis direction of the coil, the second terminal has a second base portion from which the second connecting portion is raised along the winding axis direction, A coil device in which the second lead-out portion of the coil accommodated in the second accommodating recess is in contact with the second base portion.

9. The body and A coil made of a rectangular wire and embedded inside the element body; a first terminal including a first connection portion to which a first lead portion of the coil is connected, the first connection portion being disposed inside the body; a second connection portion to which a second lead portion of the coil is connected, the second connection portion being disposed inside the body; and a second terminal, a first accommodating recess for accommodating the first drawn-out portion is formed in the first connecting portion; a second accommodating recess for accommodating the second lead-out portion is formed in the second connection portion, A coil device, wherein the first lead-out portion of the coil accommodated in the first accommodating recess is located above a bottom of the first accommodating recess.

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