JP2739334B2 - Impedance element and its manufacturing apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to an impedance element that can be surface-mounted on a substrate such as a printed wiring board formed by alternately laminating a magnetic layer made of a magnetic material and a conductor. And its manufacturing apparatus.

<Prior Art> In an electronic device, a surface mounting impedance element mounted on a substrate such as a printed wiring board is used in order to prevent electromagnetic interference from being emitted from the outside or received from the outside. Conventionally, in this type of impedance element, a magnetic sheet is formed by a printing method or a doctor blade method from a magnetic paste obtained by mixing a ferromagnetic powder such as ferrite with a binder resin and a solvent and kneading them. A conductor is printed with both ends protruding from an edge corresponding to a part of the magnetic material layer in which a plurality of the magnetic material sheets are stacked, and the magnetic material layer is again stacked thereon to form a raw laminate. The green laminate is integrally sintered, connected to both ends of the conductor, and provided with electrode terminals whose both edges are covered with a conductive material to form an impedance element. Therefore, the magnetic layer laminated on the magnetic field generated by applying a current to the conductor forms a closed magnetic path, and the electrode terminals are directly mounted on the substrate.

<Problems to be Solved by the Invention> However, in order to increase the impedance value or the DC superimposition characteristic in a desired frequency band in a conventional impedance element of this type, it is necessary to secure a sufficient magnetic path and use a magnetic material. The thickness of the layer usually needs to be about 1 mm, at least about 0.5 mm. Therefore, in the case of a printing method using a magnetic paste, the number of times or required time of the printing and drying steps is extremely large, and it is not possible to economically form an impedance element. Even when using the doctor blade method, the thickness of the magnetic sheet is several microns, and lamination up to about 1 mm requires an enormous number of laminating steps and cannot be formed economically. Further, even if a large number of conventional impedance elements are formed in the process, there is a disadvantage that the steps from formation to cutting of the individual impedance elements from the magnetic sheet cannot be consistently achieved.

<Means for Solving the Problems> The present invention eliminates the above-mentioned drawbacks. In the present invention, a binder resin and a solvent are mixed and kneaded with ferrite magnetic powder and high-melting-point metal or alloy powder such as Ag, and then kneaded. And produce a conductive paste. Here, the conductor paste is extruded between two magnetic pastes.
A conductor is sandwiched between two magnetic layers and continuously overlapped, and this is cut to a desired size and connected to a conductor in a layered body of a green laminate formed for cutting out to the outside at the cut edge. This is an impedance element provided with an electrode terminal.

Furthermore, these green laminates are filled with a magnetic paste and a magnetic head extrudes a slightly thick magnetic layer by a magnetic head, and a magnetic extruding mechanism between the upper and lower parts, and a conductor filled between the conductors and a conductor extruded by the conductor head. An impedance element manufacturing apparatus provided with an extruding mechanism and a pressing mechanism for superimposing and laminating an extruded magnetic sheet and a conductor.

<Operation> The magnetic layer extruded from the upper and lower magnetic extruding mechanisms and the conductor extruded from the conductor extruding mechanism between them become continuous strips. A continuous strip-shaped green laminate is formed. This is cut, integrally sintered, and electrode terminals are provided to obtain an impedance element.

<Embodiment> An embodiment of the impedance element of the present invention is shown in FIGS.
This is shown in the figure and FIG.

As shown in FIG. 1, a magnetic paste in which a binder resin and a solvent are mixed and kneaded with a magnetic powder such as ferrite is extruded and formed. One conductor 2 is laminated by extrusion molding from a conductor paste obtained by mixing and kneading a binder resin and a solvent with a metal or alloy powder. Further, the magnetic layer 1 'is superimposed and laminated on this upper layer to form a raw laminate 3 in which the end faces of the conductor 2 are exposed at both edges as shown in FIG. The green laminate 3 is integrally sintered at a predetermined temperature and connected to the conductors 2 exposed on both end surfaces as shown in FIG. 3 to cover the both edges of the green laminate 3 with a conductive material. 4 'is provided to form an impedance element.

Another embodiment of the impedance element according to the present invention is shown in FIGS.

As shown in FIG. 4, a plurality of parallel conductors 2, 2 ', 2 "extruded from the conductor paste are exposed on both sides of the upper side of the magnetic material layer 1 extruded from the magnetic paste. And a magnetic layer '
Are superposed and laminated to obtain a green laminate 3 as shown in FIG.
The green body layer 3 is integrally sintered at a predetermined temperature and connected to each of the conductors 2, 2 ', 2 "as shown in FIG. To form a common-mode impedance element that can be surface-mounted.

In these impedance elements or in-phase type impedance elements according to the present invention, the magnetic layer 1 is molded by one extrusion, and the number of steps is reduced as compared with the conventional method of laminating and drying a plurality of thin magnetic sheets to obtain a magnetic layer. .

FIG. 7 shows an apparatus for manufacturing an impedance element and an in-phase type impedance element according to the present invention.

As shown in the drawing, magnetic material extruding mechanisms 7, 7 'comprising upper and lower two sets of magnetic material heads 5, 5' and magnetic paste storage boxes 6, 6 'filled with magnetic paste, and a conductor head in the middle of each. 8, a conductor pushing mechanism 10 comprising a conductor paste storage box 9 filled with a conductor paste, a transport mechanism 11 for feeding them, and pressure rollers 12, 12 'for pressing and stacking the magnetic layer 1 and the conductor 2 from above and below. Thereby, a manufacturing apparatus is formed.

Now, the magnetic paste extruded from the magnetic material head 5 of the magnetic material extruding mechanism 6 becomes the magnetic material layer 1 and becomes the transfer mechanism 11.
Sent by Next, in the conductor pushing mechanism 10, the conductor paste is pushed out from the conductor head 8 onto the magnetic layer 1 and a plurality of conductors 2, 2 ', 2 "are superimposed and sent together with the magnetic layer 1 by the transport mechanism 11. A magnetic material layer 1 'extruded from a magnetic material head 5' of a magnetic material extruding mechanism 7 'provided on the top is superposed and laminated on the conductors 2, 2', 2 ". The green laminate 3 is laminated and pressure-bonded by 12 'to form a continuous green laminate 3 in a belt shape.

<Effects of the Invention> As described above, according to the present invention, the magnetic layer 1 and the conductor 2 are extruded from the magnetic paste and the conductor paste, respectively, by the manufacturing apparatus, and a consistent and continuous green laminate 3 is manufactured. Therefore, compared to the conventional method of laminating a plurality of magnetic sheets to obtain a magnetic layer, the number of laminating steps is small and an economical impedance element and an in-phase type impedance element are formed.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a green laminate in an embodiment of the impedance element of the present invention, FIG. 2 is an assembled perspective view of the green laminate assembled in FIG. 1, and FIG. FIG. 4 is an external perspective view of the provided impedance element, FIG. 4 is an exploded perspective view of a raw laminate according to another embodiment of the in-phase impedance element according to the present invention, and FIG. 5 is an external perspective view of the assembled raw laminate in FIG. FIG. 6 is an external perspective view of the in-phase impedance element provided with the electrode terminals in FIG. 5, and FIG. 7 is an external structural view showing the configuration of the manufacturing apparatus according to the present invention. Note that 1,1 ': magnetic layer, 2, 2', 2 ": conductor, 3: green laminate, 4, 4 ',
4 ": Electrode terminal, 5,5 ': Magnetic head, 6, 6': Magnetic paste storage box, 7, 7 ': Magnetic material extruding mechanism, 8: Conductor head,
9: conductor paste storage box, 10: conductor extrusion mechanism, 11: transport mechanism, 12, 12 ': pressure roller.

Claims (2)

(57) [Claims] A conductor obtained by mixing and kneading an alloy powder, a binder resin and a solvent between two magnetic layers extruded from a magnetic paste in which a ferromagnetic powder, a binder resin and a solvent are mixed and kneaded. A green laminate 3 formed by superposing and laminating parallel conductors 2, 2 ', 2 "extruded from a paste is integrally sintered, connected to each of the conductors 2, 2', 2" and connected with a conductive material. Impedance element provided with electrode terminals 4, 4 ', 4 ". 2. A conductive paste filled with said conductive paste between two upper and lower magnetic extruding mechanisms 7, 7 'comprising a magnetic paste storage box 6 filled with said magnetic paste and a magnetic head 5. A conductor extruding mechanism 10 comprising a storage box 9 and a conductor head 8 is provided, and a transport mechanism 11 for sending out a continuous green laminate 3 extruded and formed, and pressure rollers 12, 12 'for pressurizing and laminating layers from above and below are provided. Equipment for manufacturing the provided impedance element.