COIL COMPONENT AND METHOD OF MANUFACTURING THE SAME
20200258677 ยท 2020-08-13
Assignee
Inventors
- Akio IGARASHI (Nagaokakyo-shi, JP)
- Yuuji IGARASHI (Nagaokakyo-shi, JP)
- Koji ONISHI (Nagaokakyo-shi, JP)
- Takuya ISHIDA (Nagaokakyo-shi, JP)
- Takao MIYAMOTO (Nagaokakyo-shi, JP)
Cpc classification
H01F17/045
ELECTRICITY
H01F27/306
ELECTRICITY
H01F41/076
ELECTRICITY
H01F27/29
ELECTRICITY
International classification
H01F27/29
ELECTRICITY
H01F41/076
ELECTRICITY
H01F27/30
ELECTRICITY
Abstract
Advantage is taken of the fact that tin has a higher efficiency of absorption of a laser beam than, for example, copper. A method of manufacturing a coil component includes preparing a wire that includes a linear, central conductor and an insulating coating that covers a circumferential surface of the central conductor, preparing a metal terminal that is to be electrically connected to the central conductor at an end portion of the wire and that has a surface on which a tin-containing film that contains tin is disposed and above which at least the end portion of the wire is to be disposed, and welding the central conductor of the wire to the metal terminal by irradiating at least the tin-containing film with a laser beam with the end portion of the wire disposed along the tin-containing film.
Claims
1. A method of manufacturing a coil component, comprising: preparing a wire that includes a linear, central conductor and an insulating coating that covers a circumferential surface of the central conductor; preparing a metal terminal that is configured to electrically connect to the central conductor at an end portion of the wire, the metal terminal having a surface on which a tin-containing film that contains tin is disposed and above which at least the end portion of the wire is to be disposed; and welding the central conductor of the wire to the metal terminal by irradiating the tin-containing film with a laser beam with the end portion of the wire disposed along the tin-containing film.
2. The method according to claim 1, wherein the tin-containing film is a tin plating film.
3. The method according to claim 1, wherein during the welding of the central conductor of the wire to the metal terminal, the tin-containing film is irradiated with the laser beam.
4. The method according to claim 1, wherein during the welding of the central conductor of the wire to the metal terminal, the laser beam is radiated with the end portion of the wire being in contact with the tin-containing film.
5. The method according to claim 4, wherein during the welding of the central conductor of the wire to the metal terminal further includes flattening the end portion of the wire into an oblong shape and temporarily securing the end portion of the wire to the metal terminal by thermo-compression bonding of the end portion of the wire to the tin-containing film before the step of irradiation of the laser beam, and the end portion of the wire is brought into contact with the tin-containing film such that a major axis direction of a section of the oblong shape of the wire is along a surface of the tin-containing film.
6. The method according to claim 2, wherein during the welding of the central conductor of the wire to the metal terminal, the tin-containing film is irradiated with the laser beam.
7. The method according to claim 2, wherein during the welding of the central conductor of the wire to the metal terminal, the laser beam is radiated with the end portion of the wire being in contact with the tin-containing film.
8. The method according to claim 6, wherein during the welding of the central conductor of the wire to the metal terminal, the laser beam is radiated with the end portion of the wire being in contact with the tin-containing film.
9. A coil component comprising: a wire that includes a linear, central conductor and an insulating coating that covers a circumferential surface of the central conductor; and a metal terminal that is electrically connected to the central conductor of the wire and that includes a receiving portion that receives the end portion of the wire, wherein a tin-containing film that contains tin is disposed on a surface of the metal terminal that faces in the same direction as a surface of the receiving portion above which the end portion of the wire is disposed, the receiving portion includes a welded portion at which the central conductor is weld to the receiving portion, and a non-welded portion adjacent thereto, and the welded portion and the non-welded portion are arranged in this order from an end to an intermediate portion of the wire in a longitudinal direction, the welded portion includes a weld nugget portion that is integrally formed by welding the central conductor and the receiving portion and that protrudes from the surface of the receiving portion above which the end portion of the wire is disposed, and tin is distributed along or near an imaginary extension surface of the tin-containing film that extends inside the weld nugget portion.
10. The coil component according to claim 9, wherein a surface of the metal terminal that faces in the same direction as the surface on which the tin-containing film is disposed is to be soldered when the coil component is mounted.
11. The coil component according to claim 9, wherein a base material of the metal terminal is exposed from a surface of the receiving portion opposite the surface above which the end portion of the wire is disposed.
12. The coil component according to claim 11, wherein the tin inside the weld nugget portion is distributed near the surface of the receiving portion that faces in the same direction as the surface on which the tin-containing film is disposed in a larger amount than an amount in which the tin is distributed near the surface of the receiving portion opposite the surface on which the tin-containing film is disposed.
13. The coil component according to claim 9, wherein the tin-containing film is a tin plating film.
14. The coil component according to claim 9, wherein the metal terminal contains copper.
15. The coil component according to claim 9, further comprising: a core that includes a winding core portion and a flange portion that is disposed on an end portion of the winding core portion, wherein the wire is spirally wound around the winding core portion, and the metal terminal is mounted on the flange portion.
16. The coil component according to claim 10, wherein a base material of the metal terminal is exposed from a surface of the receiving portion opposite the surface above which the end portion of the wire is disposed.
17. The coil component according to claim 10, wherein the tin-containing film is a tin plating film.
18. The coil component according to claim 11, wherein the tin-containing film is a tin plating film.
19. The coil component according to claim 10, wherein the metal terminal contains copper.
20. The coil component according to claim 10, further comprising: a core that includes a winding core portion and a flange portion that is disposed on an end portion of the winding core portion, wherein the wire is spirally wound around the winding core portion, and the metal terminal is mounted on the flange portion.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
[0030]
[0031]
[0032]
DETAILED DESCRIPTION
[0033] The overall structure of a coil component 1 according to an embodiment of the present disclosure will be described with reference to
[0034] The coil component 1 includes a drum-shaped core 2. A first wire 3 and a second wire 4 are wound around the drum-shaped core 2. The drum-shaped core 2 includes a winding core portion 5 that extends in an axial direction X, and a first flange portion 6 and a second flange portion 7 that are disposed on end portions of the winding core portion 5 that are opposite each other in the axial direction X. The drum-shaped core 2 is preferably composed of ferrite. The drum-shaped core 2 may be composed of a nonconductive material other than ferrite, for example, a non-magnetic material such as alumina, or a resin that contains ferrite powder or magnetic metal powder.
[0035] The winding core portion 5, the first flange portion 6, and the second flange portion 7 that are included in the drum-shaped core 2 have, for example, a substantially quadrangular prism shape having a substantially square sectional shape. Ridge line portions of the winding core portion 5, the first flange portion 6, and the second flange portion 7 having a substantially quadrangular prism shape are preferably round-chamfered although this is not illustrated. The sectional shape of the winding core portion 5, the first flange portion 6, and the second flange portion 7 may be a substantially polygonal shape such as a hexagon, a substantially circular shape, or a substantially ellipse shape, or a combination thereof, instead of a square.
[0036] The first flange portion 6 has a bottom surface 8 that extends in the axial direction X and that is to face a mounting substrate during mounting, and an upper surface 10 opposite the bottom surface 8. The first flange portion 6 also has an inner end surface 12a that extends upward from the bottom surface 8, that extends in the direction perpendicular to the mounting substrate, and that faces the winding core portion 5, an outer end surface 12b that extends upward from the bottom surface 8, that extends in the direction perpendicular to the mounting substrate, and that faces in the direction opposite the direction toward the winding core portion 5, and a first side surface 12c and a second side surface 12d that connect the inner end surface 12a and the outer end surface 12b to each other.
[0037] Similarly to the first flange portion 6, the second flange portion 7 has a bottom surface 9 that extends in the axial direction X and that is to face the mounting substrate during mounting, and an upper surface 11 opposite the bottom surface 9. The second flange portion 7 also has an inner end surface 13a that extends upward from the bottom surface 9, that extends in the direction perpendicular to the mounting substrate, and that faces the winding core portion 5, an outer end surface 13b that extends upward from the bottom surface 9, that extends in the direction perpendicular to the mounting substrate, and that faces in the direction opposite the direction toward the winding core portion 5, and a first side surface 13c and a second side surface 13d that connect the inner end surface 13a and the outer end surface 13b to each other.
[0038] Steps that are formed so as to protrude along upper sides of the outer end surfaces 12b and 13b of the flange portions 6 and 7 are not essential and may not be formed.
[0039] A first metal terminal 16 and a third metal terminal 18 are spaced from each other and mounted on the first flange portion 6 with an adhesive. A second metal terminal 17 and a fourth metal terminal 19 are spaced from each other and mounted on the second flange portion 7 with an adhesive. Each of the first to fourth metal terminals 16 to 19 is typically manufactured by processing a metal plate that is composed of a copper alloy such as phosphor bronze or tough pitch copper. The metal plate has a thickness of no less than 0.10 mm and no more than 0.15 mm (i.e., from 0.10 mm to 0.15 mm), for example, a thickness of about 0.1 mm.
[0040] As illustrated in
[0041] In
[0042] A first end of the first wire 3 is electrically connected to the receiving portion 24 of the first metal terminal 16. A second end of the first wire 3 opposite the first end is electrically connected to the receiving portion 24 of the second metal terminal 17. A first end of the second wire 4 is electrically connected to the receiving portion 24 of the third metal terminal 18. A second end of the second wire 4 opposite the first end is electrically connected to the receiving portion 24 of the fourth metal terminal 19. These are electrically connected by laser welding with laser beam irradiation.
[0043]
[0044] As illustrated in
[0045] The first wire 3 and the second wire 4 are spirally wound around the winding core portion 5 in the same direction although an illustration thereof is omitted in
[0046] After a process of winding the first wire 3 and the second wire 4 is finished, the processes of connecting the first wire 3 and the second wire 4 and the first to fourth metal terminals 16 to 19 are performed as described below.
[0047] The process of connecting the first wire 3 to the first metal terminal 16 will now be representatively described with reference to
[0048] Right after the above winding process is finished, as illustrated in
[0049] A tin-containing film 27 that contains tin is disposed on a surface of the receiving portion 24 above which the end portion of the wire 3 is disposed. The tin-containing film 27 has a thickness of, for example, no less than 0.5 m and no more than 20 m (i.e., from 0.5 m to 20 m). The tin-containing film 27 is preferably formed in a manner in which a tin plating film is formed on a first main surface of the metal plate that corresponds to the material of the metal terminal 16. The reason is that the tin-containing film 27 can be efficiently disposed on the receiving portion 24.
[0050] The tin-containing film 27 is not limited to formation by plating and may be formed by printing paste that contains tin powder or by attaching tin foil. In the case of printing the paste that contains tin powder, however, there is a concern that a solvent is vaporized, and a blowhole is produced in the weld nugget portion 25 due to heat generated in a welding process described later. To avoid this concern, the tin-containing film 27 is preferably formed by plating or by attaching the foil.
[0051] As illustrated in
[0052] Subsequently, thermo-compression bonding of the end portion of the wire 3 to the tin-containing film 27 is performed. Consequently, as illustrated by a dashed line in
[0053] According to the embodiment, the end portion of the wire 3 and the receiving portion 24 are preferably, but not necessarily, brought into close contact with each other. When the receiving portion 24 and the end portion of the wire 3 are partly in contact with each other, the heat that causes the receiving portion 24 to melt is conducted to the wire 3, and welding can be finished in a decreased time.
[0054] Subsequently, as illustrated in
[0055] After the tin is liquified and the efficiency of absorption of the laser beam 28 is further increased as above, the base material of the receiving portion 24 such as phosphor bronze is readily melted. Consequently, as illustrated in
[0056] Conditions of irradiation of the laser beam 28 include pulse irradiation with, for example, a YAG laser, a plus width of no less than 1.0 ms and no more than 10.0 ms (i.e., from 1.0 ms to 10.0 ms), a wave length of 1064 nm, and a peak power of no less than 0.5 kW and no more than 2.0 kW (i.e., from 0.5 kW to 2.0 kW). The laser beam 28 is preferably radiated in the direction perpendicular to the surface of the tin-containing film 27 but may be inclined about 10 degrees with respect to the perpendicular direction.
[0057] It is preferable that the receiving portion 24 be slightly spaced from the drum-shaped core 2 as described above. This structure is not essential. With this structure, however, the increased temperature of the receiving portion 24 is unlikely to be conducted to the drum-shaped core 2 in the above welding process, and an adverse effect on the drum-shaped core 2 due to the heat can be reduced.
[0058]
[0059] Referring to
[0060] More specifically, the receiving portion 24 includes a welded portion 29 at which the central conductor 3a is weld to the receiving portion 24, and a non-welded portion 30 adjacent thereto, and the welded portion 29 and the non-welded portion 30 are arranged in this order from the end to an intermediate portion of the wire 3 in the longitudinal direction. In
[0061] The welded portion 29 includes the weld nugget portion 25 that is integrally formed by welding the central conductor 3a and the receiving portion 24 and that protrudes from the surface of the receiving portion 24 above which the end portion of the wire 3 is disposed, that is, the surface on which the tin-containing film 27 is disposed. Tin 27a is distributed along or near an imaginary extension line of the tin-containing film 27 that extends inside the weld nugget portion 25. In
[0062] Attention is paid to the surface of the metal terminal 16 on which the tin-containing film 27 is disposed. In the above description, the tin-containing film 27 is disposed on the surface of the receiving portion 24 above which the end portion of the wire 3 is disposed. The tin-containing film 27 is typically disposed on an entire first main surface of the metal plate that corresponds to the material of the metal terminal 16. The basal portion 20, the rising portion 23, and the receiving portion 24, for example, are formed by bending the metal plate. In this case, as illustrated in, for example,
[0063] Accordingly, the tin-containing film that is disposed on the first main surface of the metal plate has a function of decreasing the time of laser welding for connecting the wire 3 to the receiving portion 24 of the metal terminal 16 and a function of improving solder wettability when the metal terminal 16 is soldered.
[0064] However, the tin-containing film is typically not disposed on a second main surface of the metal plate. Accordingly, in the case where the receiving portion 24 is formed such that the metal plate is not folded, the base material of the metal terminal 16 is exposed form the surface of the receiving portion 24 opposite the surface above which the end portion of the wire 3 is disposed. As seen from, for example,
[0065] The connection between the first metal terminal 16 and the first wire 3 is described above. The same processes are performed for the connections between the other metal terminals 17 to 19 and the wire 3 or 4, and the same connection structure is obtained.
[0066] The use of a welding method and a weld structure described above for the coil component 1 illustrated in
[0067] After the above process of winding the first and second wires 3 and 4, and the processes of connecting the first and second wires 3 and 4 to the first to fourth metal terminals 16 to 19, as illustrated in
[0068] A nickel film may be disposed below the tin-containing film 27 in the first metal terminal 16. The plate core 32 may be replaced with a magnetic resin plate or a metal plate that can form a magnetic circuit. The coil component 1 may not include the plate core 32.
[0069] A coil component according to the present disclosure is described above on the basis of the embodiment of the common-mode choke coil. The embodiment is described by way of example, and other various modifications can be made. Features can be partially replaced or combined between embodiments.
[0070] The number of the wires included in the coil component, the winding direction of the wires, and the number of the metal terminals, for example, can be changed in accordance with the function of the coil component.
[0071] A coil component according to the present disclosure may include no core such as the drum-shaped core.
[0072] While preferred embodiments of the disclosure have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the disclosure. The scope of the disclosure, therefore, is to be determined solely by the following claims.