JP3177893B2 - Surface mount electronic components - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a surface mount electronic component such as a laminated transformer or an in-phase type inductance element.

(Prior Art) As shown in FIG. 9, a laminated transformer as an example of a conventional surface mount electronic component includes at least two or more linear or meandering printed conductors between upper and lower magnetic sheets 911 and 912.
Films 913 and 915 are formed so as to be substantially overlapped with each other with the printed insulating layer 914 interposed therebetween and excluding the end portions 923A and 925A of the printed conductor. Electrode terminals 933A, 933B, 935A, 935B
Was provided.

(Problems to be Solved by the Invention) However, the configuration of the conventional transformer described above and the plurality of printed conductor layers are one circuit in structure. Therefore, the current capacity cannot be increased, and it is difficult to reduce the distance between the printed conductor layers, and the magnetic resistance of the magnetic path portion between the printed conductors among the magnetic paths due to the current flowing through the conductors is reduced. As a result, the leakage inductance component increases. As a result, there is a fatal defect that the conversion efficiency as a transformer is greatly reduced.

Therefore, a technical object of the present invention is to provide a high-performance surface-mounted electronic component by eliminating the disadvantages of the conventional technology.

(Means for Solving the Problems) According to the present invention, upper and lower magnetic portions sintered and integrated with each other, a plurality of printed conductors interposed between the magnetic portions with a positional relationship overlapping each other, A printed insulating magnetic layer interposed between each of the plurality of printed conductors to insulate the printed conductors, wherein the plurality of printed conductors are intermediately disposed with a plurality of vertically separated end printed conductors. Consists of a plurality of intermediate printed conductors located, the plurality of end printed conductors and the plurality of intermediate printed conductors, the plurality of end printed conductors and the plurality of intermediate printed conductors By a plurality of film-shaped electrode terminals separately at the end faces of the upper and lower magnetic portions, the plurality of end printed conductors were connected in parallel with each other and the plurality of intermediate printed conductors were connected in parallel with each other. Surface mount device characterized by the following: A child part is obtained.

Embodiment An embodiment of the present invention will be described below in detail with reference to the drawings.

FIGS. 1, 2 and 3 show a laminated transformer which is one of the surface mount electronic components according to the first embodiment of the present invention. I have.

In FIG. 1, an end is formed on a first magnetic sheet 11 formed by kneading a raw insulating ferrite powder and an appropriate binder resin by using a high melting point metal paste such as Ag or Ag alloy paste. Except for this, the first straight conductor 13 located substantially at the center of the magnetic sheet 11 is printed. Next, the second linear conductor 13 is overlapped with the first straight conductor 13 in the laminating direction except for the end portion.
The first insulating magnetic layer 14 is printed using an insulating magnetic paste obtained by kneading the insulating ferrite powder and an appropriate binder resin so as to include at least the surface facing the conductor 15. Further, after the second conductor 15 is similarly formed by printing, a second insulating magnetic layer 16 similar to the first insulating magnetic layer 14 is printed. Similarly, the third conductor 15 ', the third insulating magnetic layer 17, and the fourth conductor 13' are formed by printing. After that, a second magnetic sheet 12 similar to the first magnetic sheet 11 is superimposed to form a laminate as shown in FIG. 2 to form the first, second, third and fourth conductors.
A closed-magnetic-path-type laminate is formed including the end portions of 13,15,15 'and 13'. Next, the laminate is integrally sintered at an appropriate temperature. As a result, the first and second magnetic sheets
The upper and lower magnetic members 11 and 12 are sintered and integrated. Thereafter, the film-shaped electrode terminals 35A, 35B, as shown in FIG. 3 connected to the first, second, third, and fourth conductors 13, 15, 15 ', 13' on the end surfaces of the magnetic body, respectively. 33A and 33B are provided by baking or plating. As in the equivalent circuit shown in FIG. 4, a laminated transformer suitable for surface mounting in an electronic circuit and capable of handling high frequencies is configured simply and with high performance.

That is, since the start and end of the conductor are located on the opposing surfaces and are linear conductors, the parasitic capacitance can be reduced and the decrease in the self-resonant frequency can be greatly suppressed. Moreover, the first, second,
A description will be given of a magnetic path component between conductors acting as a leakage inductance component among magnetic paths generated by a current flowing through a conductor in which third and fourth primary sides and secondary sides are alternately stacked. Since the conductors substantially overlap each other in the laminating direction with a thin insulating magnetic layer interposed therebetween, the magnetic resistance of the conductor-to-conductor portion is reduced by the four sets of conductors while ensuring a sufficient dielectric strength between conductors. It can be larger than the main magnetic resistance of the upper and lower two magnetic portions on the outer circumference that is included. As a result, a reduction in the coupling coefficient of the transformer can be significantly suppressed, and a high-performance, high-coupling-coefficient transformer suitable for high-frequency operation can be constructed at a low cost by a simple process.

FIGS. 5, 6, and 7 show a laminated transformer according to a second embodiment of the present invention. As shown in FIG. This embodiment shows a meandering conductor configuration in contrast to a configuration in which the primary side and the secondary side are alternately stacked in one set of two circuits of linear conductors.

The details will be described below. Similarly to the first embodiment, a meandering fifth conductor 53 is printed on the raw magnetic sheet 51 made of insulating ferrite in FIG. 5 by using the refractory metal paste. Next, an insulating magnetic layer 54 is printed and laminated using the magnetic insulating paste, and the sixth meandering conductor 55, the magnetic insulator layer 56, and the seventh meandering conductor are similarly formed.
55 ', the magnetic insulator layer 57, and the eighth meandering conductor 53' are sequentially laminated and printed. Finally, the magnetic sheet 52 is superimposed, and
As shown in FIG. 6, the two meandering conductor portions overlap each other via the magnetic insulator layer to form a closed magnetic circuit type laminate. Similarly, film-like terminals 73A, 73B, 75A, and 75B connected to the respective conductors as shown in FIG. 7 are provided by integrally sintering to form a two-circuit type surface mount shown in the equivalent circuit of FIG. Form a suitable laminated transformer.

In the configuration of the closed magnetic circuit type according to the present embodiment, by forming the meandering conductor between the opposed end faces, the inductance value or the impedance value generated between the terminals can be sufficiently increased as compared with the straight conductor of the previous example.

Also, the secondary conductor is sandwiched between the primary conductors or the primary conductor is sandwiched between the secondary conductors, and the insulating layer interposed between the meandering conductors is the magnetic insulating paste. Since the size of the magnetic insulator layer is the same as that of the magnetic sheet, such as 54, 56, and 57, no problem occurs in the closed magnetic circuit configuration, and the dielectric strength between conductors is secured as described above. However, since the leakage inductance component can be sufficiently reduced, a multilayer transformer having a high excitation inductance and a high coupling coefficient can be obtained.

In the embodiment, the laminated transformer having two conductors is described, but an in-phase inductor can be obtained in the same manner.

The upper and lower magnetic sheets may be formed by printing or by a doctor blade method.

(Effect of the Invention) As described above, according to the surface mount electronic component of the present invention,
The current capacity can be increased, and the number of required steps can be reduced with a simple configuration and the manufacturing cost can be reduced. In addition, since a plurality of vertically separated end printed conductors and a plurality of intermediate printed conductors positioned in the middle are connected to different electrode terminals, the equivalent stray capacitance between the printed conductors can be reduced, and therefore high frequency A transformer or an inductance element having excellent characteristics can be provided. Furthermore, since the equivalent stray capacitance can be reduced with the low leakage inductance type, a device with high conversion efficiency can be obtained. Therefore, it can be said that it can be realized to correspond to a high frequency band, and that the industrial benefit is extremely great.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view for explaining the configuration of a laminated transformer as a surface mount electronic component according to a first embodiment of the present invention, and FIG. 2 is an external view of the laminated transformer of FIG. 1 before electrode terminals are attached. 3 is an external view of a laminated transformer as a surface mount electronic component according to the first embodiment of the present invention, and FIG.
5 is an equivalent circuit diagram of the laminated transformer shown in FIG.
FIG. 6 is an exploded perspective view for explaining the configuration of a laminated transformer as a surface mount electronic component according to the embodiment of the present invention, FIG. 6 is an external view of the laminated transformer of FIG. 5 before electrode terminals are attached, and FIG. 8 is an external view of a laminated transformer as a surface mounted electronic component according to the second embodiment, FIG. 8 is an equivalent circuit diagram of the laminated transformer of FIG. 7, and FIG. 9 (a) is a diagram of a conventional laminated transformer as a surface mounted electronic component. Exploded perspective view for explaining the configuration,
FIG. 9 (b) is an external view of the multilayer transformer of FIG. 9 (a) before electrode terminals are mounted, and FIG. 9 (c) is an external view of a conventional multilayer transformer as a surface mount electronic component. In the figure, 11,12 ... magnetic sheet, 13,13'15,15 '... conductor, 14,1
6,17 …… Insulator layer, 23A, 23A ′, 25A, 25A ′ …… Conductor, 33A, 3
3B, 35A, 35A '... electrode terminal, 43A, 43B, 45A, 45B ... electrode terminal, 51, 52 ... magnetic sheet, 53, 53', 55, 55 '... conductor, 5
4,56,57 …… Insulating magnetic layer, 63A, 63A ′, 65A, 65A ′ …… Conductor, 73A, 73B, 75A, 75B …… Electrode terminal, 83A, 83B, 85A, 85B ……
Electrode terminal.

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-79307 (JP, A) JP-A-58-89819 (JP, A) JP-A-59-229808 (JP, A) JP-A-51- 81933 (JP, A) Japanese Utility Model Showa 57-6216 (JP, U) Japanese Utility Model Showa 62-2610 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01F 17/00 H01F 15 /Ten

Claims (1)

(57) [Claims] An upper and lower magnetic body portion that is sintered and integrated, a plurality of printed conductors interposed between the magnetic body portions with a positional relationship overlapping each other; A printed insulating magnetic layer interposed between each of the plurality of printed conductors, wherein the plurality of printed conductors comprises a plurality of vertically separated end printed conductors and a plurality of intermediate printed conductors positioned in the middle. The plurality of end printed conductors and the plurality of intermediate printed conductors are separated from each other at the end faces of the upper and lower magnetic portions by a plurality of film-shaped electrode terminals. A surface-mounted electronic component, wherein the plurality of intermediate printed conductors are connected so as to be in parallel with each other.