Method of manufacturing winding-type coil component

Abstract

A method of manufacturing a winding-type coil component, wherein at the time of manufacturing the winding-type coil component, the method can efficiently form an inclined external electrode, can change inclination of an external electrode, and can satisfy a demand for the manufacture of plural kinds of winding-type coil components provided with external electrodes having different inclination angles respectively.

Claims

1. A coil component comprising: a core including a winding core portion; a first flange portion provided at one end of the winding core portion and including a first inner surface, a first outer surface, and a first main surface extending between the first inner surface and the first outer surface; a second flange portion provided at another end of the winding core portion and including a second inner surface, a second outer surface, and a second main surface extending between the second inner surface and the second outer surface; a first external electrode disposed on the first flange portion; a second external electrode disposed on the second flange portion; and a winding wound on the winding core portion; wherein the first external electrode includes a first upper side located on and extending across the first main surface of the first flange portion; the second external electrode includes a second upper side located on and extending across the second main surface of the second flange portion; and an inclination of the first upper side is different from an inclination of the second upper side.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1(a) and FIG. 1(b) are views showing one example of a winding-type coil component manufactured by a method of the present disclosure, wherein FIG. 1(a) is a front view, and FIG. 1(b) is a side view.

(2) FIG. 2 is a view for describing a method of manufacturing a winding-type coil component according to Embodiment 1 of the present disclosure, and is also a view showing a state where core members are held on a holding member.

(3) FIG. 3 is a view showing “a first stage of a coating step” where an electrode paste is applied by coating to a region of each core member where an external electrode provided on a first-side flange portion of the core member is to be formed in the method of manufacturing a winding-type coil component according to Embodiment 1 of the present disclosure.

(4) FIG. 4 is a view showing “a second stage of the coating step” where the electrode paste is applied by coating to the region of the core member where the external electrode provided on the first-side flange portion of the core member is to be formed in the method of manufacturing a winding-type coil component according to Embodiment 1 of the present disclosure.

(5) FIG. 5 is a view showing a state where the electrode paste is applied by coating to the first-side flange portion in “the first stage of the coating step”.

(6) FIG. 6 is a view showing a state where the electrode paste is applied by coating to the first-side flange portion in “the second stage of the coating step”.

(7) FIG. 7 is a view showing a state where the core members are transferred to a transfer sheet in one step of the method of manufacturing a winding-type coil component according to Embodiment 1 of the present disclosure.

(8) FIG. 8 is a view showing a state where the core members are held on the holding member so as to apply the electrode paste to second-side flange portions by coating in one step of the method of manufacturing a winding-type coil component according to Embodiment 1 of the present disclosure.

(9) FIG. 9 is a view for describing a method of manufacturing a winding-type coil component according to Embodiment 2 of the present disclosure, and is also a view showing a state where a core member is held on a holding member.

(10) FIG. 10 is a view showing “a first stage of a coating step” where an electrode paste is applied by coating to a region of the core member where an external electrode provided on a first-side flange portion of the core member is to be formed in the method of manufacturing a winding-type coil component according to Embodiment 2 of the present disclosure.

(11) FIG. 11 is a view showing “a second stage of the coating step” where the electrode paste is applied by coating to the region of the core member where the external electrode provided on the first-side flange portion of the core member is to be formed in the method of manufacturing a winding-type coil component according to Embodiment 2 of the present disclosure.

(12) FIG. 12 is a view showing a winding-type coil component manufactured by a conventional method of manufacturing a winding-type coil component.

(13) FIG. 13 is a view showing the method of manufacturing a winding-type coil component in FIG. 12.

DETAILED DESCRIPTION

(14) Hereinafter, the technical features of the present disclosure are described in further detail in conjunction with embodiments of the present disclosure.

Embodiment 1

(15) In Embodiment 1, a method of manufacturing a winding-type coil component (winding type inductor) having a structure shown in FIG. 1(a) and FIG. 1(b) is described by mainly focusing on steps for forming external electrodes on a core member.

(16) A winding-type coil component 10 manufactured in Embodiment 1 includes: a core member 1 having a winding core portion 2 and a pair of flange portions (a first-side flange portion 3a and a second-side flange portion 3b) which is connected to both ends of the winding core portion 2; a pair of external electrodes (external electrodes 4a, 4b) disposed on the first-side flange portion 3a and the second-side flange portion 3b of the core member 1; and a winding 5 wound on the winding core portion 2. Both ends of the winding 5 are connected to the external electrodes 4a, 4b respectively by soldering or the like.

(17) The external electrodes 4a, 4b are formed as follows so as to prevent the occurrence of drawbacks such as lowering of a characteristic such as a magnetic field and rounding around of solder to a coil (winding 5). The external electrodes 4a, 4b are not formed on first surfaces (opposedly-facing surfaces) of the first-side flange portion 3a and the second-side flange portion 3b which opposedly face each other, while the external electrodes 4a, 4b are formed such that the heights of the formed external electrodes 4a, 4b are increased from the opposedly-facing surface sides toward second surface sides of the first-side flange portion 3a and the second-side flange portion 3b opposite to the opposedly-facing surfaces. That is, the external electrodes 4a, 4b are formed in a mode where upper sides of the external electrodes on side surfaces of the first-side flange portion 3a and the second-side flange portion 3b are inclined. In this embodiment, a case is exemplified where the electrode is not formed on an inner wall surface of the flange portion. However, the electrode structure is not limited to the above-mentioned structure. The electrodes may also be formed on the inner wall surfaces of the flange portions provided that heights of the external electrodes 4a, 4b formed on the inner wall surfaces are lower than heights of the external electrodes 4a, 4b formed on outer wall surfaces of the flange portions.

(18) Further, a ceramic-based material (alumina, ferrite or the like, for example), a metal magnetic material or the like may be used as a material for forming the core member 1.

(19) Silver, copper or the like may be used as a material for forming the external electrode 4a, 4b.

(20) The present disclosure is also applicable to a case of manufacturing a winding-type coil component where the winding 5 is protected by a protection member made of a material which contains a thermosetting resin such as an epoxy resin as a main component.

(21) Next, a method of manufacturing the winding-type coil component 10 is described.

(22) First, a core member 1 shown in FIG. 1(a) and FIG. 1(b) is prepared. The core member 1 includes: the winding core portion 2; and the pair of flange portions (the first-side flange portion 3a and the second-side flange portion 3b) which is connected to both ends of the winding core portion 2.

(23) Next, the external electrodes 4a, 4b are formed in accordance with steps described hereinafter.

(24) (a) First, as shown in FIG. 2, the core members 1 are held on the holding member 11 having adhesiveness and elasticity in such a manner that the core members 1 are detachably holding the core members held on a main surface 11a of the holding member 11.

(25) In Embodiment 1, as a holding member, the holding member 11 made of silicone rubber or the like, for example, and having adhesiveness and elasticity is used. The holding member 11 has a plurality of V-shaped grooves 12 each of which is formed of an inclined surface (first-side inclined surface) 12a having a predetermined angle θ with respect to the main surface 11a and another inclined surface (second-side inclined surface) 12b thereon.

(26) The main surface 11a of the holding member 11 is a surface formed of regions of the holding member 11 except for regions where the V-shaped grooves 12 each having the first-side inclined surface 12a and the second-side inclined surface 12b are formed. In Embodiment 1, the main surface 11a of the holding member 11 means a surface indicated by a line L in FIG. 2.

(27) To make the holding member 11 hold the core members 1, each core member 1 is held on the holding member 11 such that the first-side flange portion 3a and the second-side flange portion 3b of the core member 1 are adhered to and held on the first-side inclined surface 12a of the holding member, and the core member 1 assumes a posture that an axis 2a of the winding core portion 2 of the core member 1 has an inclination of a predetermined inclination angle with respect to the main surface 11a of the holding member 11, and a region R1 of the core member 1 where the external electrode 4a formed on the first-side flange portion 3a of the core member 1 (FIG. 1(a)) is to be formed protrudes more from the main surface 11a of the holding member 11 than the second-side flange portion 3b.

(28) (b) Next, as shown in FIG. 3, the holding member 11 and a surface plate 16 are made to opposedly face each other such that the main surface 11a of the holding member 11 and a surface 16a of the surface plate 16 become parallel to each other. Then, the holding member 11 is moved toward the surface plate 16, and the regions R1 of the core members 1 held on the holding member where the external electrodes 4a formed on the first-side flange portions 3a of the core members 1 (FIG. 1(a)) are to be formed are brought into contact with the surface plate (table) 16 on the surface 16a of which an electrode paste layer 15 is formed. At this stage of operation, as shown in FIG. 3, the regions R1 are brought into contact with the surface plate 16 to an extent that the holding member 11 is not deformed (a first stage of a coating step). As a result, an inclination angle θ1 of the axis 2a of the winding core portion 2 of the core member 1 with respect to the main surface 11a of the holding member 11 becomes equal to an inclination angle θ of the first-side inclined surface 12a. At this stage of operation, an inclination angle θ2 of the axis 2a with respect to the surface 16a of the surface plate 16 also becomes equal to the above-mentioned inclination angle θ1.

(29) In the first stage of the coating step, as shown in FIG. 5, a coating film (inclined coating film) 15a formed using the electrode paste 15 is formed such that the coating film 15a reaches an intermediate portion of the first-side flange portion 3a in the width direction from an outer wall surface side of the first-side flange portion 3a.

(30) (c) Then, as shown in FIG. 4, each holding member 11 is further pressed toward the surface plate 16 so as to change a posture of the core member 1 such that the inclination of the axis 2a of the winding core portion 2 of the core member 11 changes from the inclination of the axis 2a of the winding core portion 2 in the first stage of the coating step (at this stage of operation, the holding member 11 having elasticity is deformed so that a change in posture of the core member 1 is allowed) (a second stage of the coating step). That is, in the second stage of the coating step, the holding member 11 is deformed due to a force which presses the holding member 11 to the surface plate 16 so that an inclination angle θ3 of the axis 2a of the winding core portion 2 of the core member 1 with respect to the surface 16a of the surface plate 16 becomes smaller than the inclination angle θ2 of the axis 2a of the winding core portion 2 with respect to the surface 16a of the surface plate 16 in the above-mentioned first stage of the coating step.

(31) As a result, although the coating film 15a formed using the electrode paste 15 is formed ranging from the outer wall surface side of the first-side flange portion 3a to the intermediate portion of the first-side flange portion 3a in the width direction in the first stage of the coating step as shown in FIG. 5, in the second stage of the coating step, as shown in FIG. 6, the coating film 15a formed using the electrode paste 15 is formed on the entire first-side flange portion 3a in the width direction ranging from the outer wall surface side to an inner wall surface side of the first-side flange portion 3a. The coating film (electrode paste coating pattern) 15a formed of the electrode paste 15 which is formed in the second stage of the coating step has a pattern (electrode paste coating pattern) which is inclined such that a height of the pattern is gradually increased from the inner wall surface side to the outer wall surface side. The coating film 15a becomes the external electrode 4a after the coating film 15a is baked.

(32) In further pressing the holding member 11 toward the surface plate 16 in the second stage of the coating step so as to make the above-mentioned inclination angle θ3 of the axis 2a of the winding core portion 2 of the core member 11 smaller than the inclination angle θ2 of the axis 2a of the winding core portion 2 in the first stage of the coating step (that is, the inclination angle θ3 being set to θ2−α(θ3=θ2−α)), appropriate conditions are set by taking into account elasticity of the holding member 11, a shape of the core member 1, the pressing direction when the holding member 11 is pressed to the surface plate 16 and the like.

(33) (d) Next, as shown in FIG. 7, the core members 1 held on the holding member 11 are transferred onto a transfer sheet 20. At this stage of operation, the coating film (electrode paste coating pattern) 15a is formed on each of the core members 1 by applying the electrode paste 15 to the first-side flange portion 3a. The transfer sheet 20 is a transfer sheet which exhibits adhesiveness larger than adhesiveness of the holding member 11 at the time of transferring the core members 1 and whose adhesiveness of the transfer sheet 20 can be lost after the core members 1 are transferred to the transfer sheet 20. By pressing the core members 1 held on the holding member 11 to the transfer sheet 20, it is possible to transfer the core members 1 to the transfer sheet 20 having a larger adhesive force than the holding member 11 with certainty.

(34) In Embodiment 1, a sheet whose adhesiveness is lost by irradiating ultraviolet rays to the sheet (UV sheet) is used as the transfer sheet 20.

(35) (e) Then, as shown in FIG. 8, the core members 1 disposed on the transfer sheet 20 whose adhesiveness is lost by irradiating ultraviolet rays to the sheet 20 are adhered to and held on the other inclined surface (second-side inclined surface) 12b which differs from the first-side inclined surface 12a of the holding member 11 in a posture where the axis 2a of the winding core portion 2 of each core member 1 has the inclination of a predetermined angle with respect to the main surface 11a of the holding member 11, and the region R2 of each core member 1 where the external electrode 4b formed on the second-side flange portion 3b of each core member 1 (FIG. 1(a)) is to be formed protrudes more from the main surface 11a of the holding member 11 than the first-side flange portion 3a.

(36) (f) Next, using the same method as the method described in the above-mentioned (b) and (c), an electrode paste is applied by coating to the region R2 of each core member 1 where the external electrode 4b formed on the second-side flange portion 3b of each core member 1 (FIG. 1(a)) is to be formed. At this stage of operation, as described in the above-mentioned (b) and (c), the electrode paste is applied by coating to each region R2 through the first stage of the coating step and the second stage of the coating step so that a following pattern (electrode paste coating pattern) is formed. That is, the electrode paste coating pattern ranges from a first surface side (inner wall surface side) of the second-side flange portion 3b which opposedly faces the first-side flange portion 3a (FIG. 1(a)) to a second surface side (outer wall surface side) of second-side flange portion 3b opposite to the first surface side and, at the same time, the electrode paste is inclined such that a height of the electrode paste coating pattern is gradually increased from the inner wall surface side to the outer wall surface side.

(37) Then, the core member 1 on which the electrode paste coating patterns are formed by applying the electrode paste to the region R1 where the external electrode provided on the first-side flange portion 3a is to be formed and the region R2 where the external electrode provided on the second-side flange portion 3b is to be formed is baked. By baking the electrode paste to the core member 1, it is possible to obtain the core member 1 provided with the pair of external electrodes 4a, 4b having a predetermined shape on the first-side flange portion 3a and the second-side flange portion 3b (FIG. 1(a), (b)).

(38) Then, the winding 5 is wound on the winding core portion 2 of the core member 1, and both ends of the winding 5 are connected to the external electrodes 4a, 4b by soldering or the like thus obtaining the winding-type coil component 10 having the structure shown in FIG. 1(a) and FIG. 1(b).

(39) As described above, according to the method of manufacturing a winding-type coil component of Embodiment 1, it is possible to form the core member provided with the external electrodes which are inclined such that heights of the external electrodes are gradually increased from the inner wall surface sides to the outer wall surface sides of the first-side flange portion and the second-side flange portion (inclined external electrode) with certainty.

(40) As a result, it is possible to manufacture a highly reliable winding-type coil component provided with the inclined external electrodes having high shape accuracy with certainty.

(41) Further, according to the method of manufacturing a winding-type coil component of Embodiment 1, the inclination of the external electrode can be changed and hence, the method can satisfy a demand for the manufacture of plural kinds of winding-type coil components provided with external electrodes having different inclination angles respectively.

Embodiment 2

(42) FIG. 9 is a view showing a state where a core member 1 is held on a holding member 11 in another embodiment (Embodiment 2) of the present disclosure. FIG. 10 is a view showing a state where a region R1 of the core member 1 held on the holding member 11 where an external electrode 4a formed on a first-side flange portion 3a (FIG. 1(a)) is to be formed is brought into contact with a surface plate 16 where an electrode paste layer is formed on a surface 16a of the surface plate 16 by applying an electrode paste 15 to the surface 16a.

(43) In Embodiment 2, as shown in FIG. 9, the core member 1 is held on the holding member 11 such that an outer wall surface 3b.sub.1 of a second-side flange portion 3b of the core member 1 is adhered to and held on a first-side inclined surface 12a of the holding member 11, and the core member 1 assumes a posture that an axis 2a of a winding core portion 2 of the core member 1 has an inclination of a predetermined angle with respect to a main surface 11a of the holding member 11 and the region R1 of the core member 1 where an external electrode 4a formed on the first-side flange portion 3a of the core member 1 (FIG. 1(a)) is to be formed protrudes more from the main surface 11a of the holding member 11 than a second-side flange portion 3b.

(44) Next, as shown in FIG. 10, the region R1 of the core member 1 held on the holding member 11 where the external electrode 4a formed on the first-side flange portion 3a (FIG. 1(a)) is to be formed is brought into contact with the surface plate 16 where the electrode paste layer is formed by applying the electrode paste 15 to the surface 16a. At this stage of operation, as shown in FIG. 10, the region R1 is brought into contact with the surface plate 16 to an extent that the holding member 11 is not deformed (a first stage of a coating step).

(45) Then, as shown in FIG. 11, the holding member 11 is further pressed toward the surface plate 16 so that a posture of the core member 1 is changed thus changing the inclination of an axis 2a of a winding core portion 2 of the core member 11 with respect to the surface 16a of the surface plate 16 (a second stage of the coating step).

(46) At this stage of operation, the holding member 11 having elasticity is deformed so that a change in posture of the core member 1 is allowed.

(47) As a result, through the above-mentioned first stage of the coating step and second stage of the coating step, it is possible to form a pattern (electrode paste coating pattern) where the pattern ranging from a first surface side (inner wall surface side) of the first-side flange portion 3a which opposedly faces the second-side flange portion 3b (FIG. 1(a)) to a second surface side (outer wall surface side) of the first-side flange portion 3a opposite to the first surface side, at the same time, the pattern is inclined such that a height of the pattern is gradually increased from the inner wall surface side to the outer wall surface side.

(48) Thereafter, although not particularly shown in the drawing, the core members 1 are transferred to a transfer sheet using a method substantially equal to the method described in Embodiment 1 and, thereafter, the core members 1 are held such that an outer wall surface 3a.sub.1 of the first-side flange portion 3a of the core member 1 is adhered to and held on a second-side inclined surface 12b of the holding member 11, and the core member 1 assumes a posture that a region R2 of the core member 1 where an external electrode 4b formed on the second-side flange portion 3b of the core member 1 (FIG. 1(a)) is to be formed protrudes more from the main surface 11a of the holding member 11 than the first-side flange portion 3a.

(49) Then, through the above-mentioned first stage of the coating step and first stage of the coating step, a pattern (electrode paste coating pattern) which is inclined such that a height of the pattern is gradually increased from the inner wall surface side to the outer wall surface side is also formed on the second-side flange portion 3b.

(50) Thereafter, through a step of baking the electrode paste coating pattern, a step of winding a winding on the winding core portion, and a step of connecting both ends of the winding to the external electrodes using a method substantially equal to the method described in Embodiment 1, a winding-type coil component such as shown in FIG. 1(a) and FIG. 1(b) can be acquired.

(51) Also in the method of manufacturing a winding-type coil component of Embodiment 2, in the same manner as the above-mentioned Embodiment 1, it is possible to manufacture a highly reliable winding-type coil component provided with the inclined external electrodes having high shape accuracy with certainty.

(52) Also in the method of manufacturing a winding-type coil component of Embodiment 2, inclination of the external electrode can be changed so that the method can satisfy a demand for the manufacture of plural kinds of winding-type coil components provided with external electrodes having different inclination angles respectively.

(53) In the above-mentioned Embodiments 1 and 2, the description has been made by taking the case where the first-side inclined surface and the second-side inclined surface are formed of a pair of inclined surfaces which forms a V-shaped groove as an example. However, it may be also possible to adopt the configuration where the first-side inclined surface and the second-side inclined surface are formed of a pair of inclined surfaces which forms a groove having an inverted trapezoidal shape, for example.

(54) It may be also possible to adopt the configuration where the first-side inclined surface and the second-side inclined surface are not formed of inclined surfaces which form portions of a groove.

(55) In the above-mentioned embodiments, as the transfer sheet, the sheet whose adhesiveness is lost by irradiating ultraviolet rays to the sheet (UV sheet) is used. However, it may be also possible to use a sheet whose adhesiveness is lost by heating the sheet (heat peel off sheet) as the transfer sheet.

(56) The present disclosure is not limited to the above-mentioned embodiments in other configurations. Various variations and modifications can be made with respect to the specific configuration of the core member and the specific configuration of the holding member within the scope of the present disclosure.