JPH062672U - Multilayer LC filter - Google Patents

Abstract

(57) [Summary] [Purpose] Adjust the stray capacitance, which was generated in the inductor part of the filter in the past to affect the characteristics of the filter, and that was difficult to control, to a desired value, and then adjust the characteristics of the filter in advance. Providing a laminated LC filter that can be designed. A laminated LC filter in which a laminated capacitor portion having internal electrodes facing each other inside a dielectric ceramic body and a laminated inductor portion having a coil conductor inside a magnetic ferrite body are connected to each other by external terminals to be integrally formed. In other words, the same pattern is not connected to the coil so as to face the end pattern F having the lead-out portion 6 which constitutes the coil end portion of the inductor portion in which the coil is formed in the magnetic body by the through hole 3. Stray capacitance adjustment pattern 7
It is easy to control the stray capacitance value by adjusting the distance between these patterns.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a laminated LC filter.

[0002]

[Prior art]

 The multilayer LC filter is formed by stacking a multilayer inductor in which a coil conductor is internally provided in a magnetic material philite body and a multilayer capacitor in which internal electrodes facing each other are internally provided in a dielectric ceramic body, and which is integrally formed. External electrodes for LC connection are formed on the end faces of the laminated body element from which the counter electrode and the coil conductor end are respectively led out.

In such a laminated LC filter, a plurality of capacitors and inductors are provided inside the element body as necessary to form a filter circuit.

[0004] LC filters are manufactured by setting respective L or C constants, but the obtained filters often have unpredictable stray capacitances, and often exhibit characteristics contrary to the initial expectations. Therefore, each time, a new coil conductor pattern with different layout, alignment, etc. is prepared and manufactured by the cut-and-try method to obtain an LC chip component having desired characteristics.

[0005]

[Problems to be solved by the device]

 Since the conventional laminated LC filter has a plurality of inductors and a plurality of capacitors inside a small element, stray capacitance is generated and affects the filter circuit. Moreover, it is difficult to control such a stray capacitance to a predetermined value even if the constant of L or C is changed as described above, and thus the obtained filter does not exhibit a predesigned LC characteristic. was there.

An object of the present invention is to design a filter characteristic in advance by adjusting a stray capacitance which is generated in an inductor portion of a conventional filter and has an effect on the filter characteristic and which is difficult to control, to a desired value. It is to provide a laminated LC filter that can be manufactured.

[0007]

[Means for Solving the Problems]

 As a result of research to achieve the above object, the present inventor has laminated inductor parts of an LC filter, that is, magnetic material sheets on which a coil conductor pattern is printed, to form a spiral coil, and to start and end the coil. Are formed by connecting to the respective external terminals by additionally laminating sheets printed with pattern conductors that do not form part of the coil on the inductor part, that is, the end pattern that forms the coil end part. If a sheet on which the same pattern as the end pattern is printed is laminated on the outer side of the printed sheet of, and the non-printed sheet is sandwiched between the two, the interval between the opposing patterns can be changed. The inventors have found that the stray capacitance can be adjusted relatively easily and arrived at the present invention.

Therefore, according to the present invention, a laminated inductor having a coil conductor provided inside a magnetic ferrite body and a laminated capacitor having positive and negative internal electrodes opposite to each other provided inside a dielectric ceramic body are integrated. In the laminated LC filter configured as described above, a conductor having the same pattern as the end pattern conductor is connected as a part of the coil to the outside of the end pattern conductor forming the coil end part of the inductor part. In addition, the present invention provides a laminated LC filter, which is internally provided so as to face the end pattern at a predetermined interval via a magnetic body.

FIG. 1 is a laminated exploded perspective view showing a basic coil conductor pattern and a stray capacitance adjusting pattern in an inductor portion of a laminated LC filter according to the present invention. In contrast to FIG. F), the same pattern as this is laminated as a floating capacitance adjusting pattern 7 via a magnetic material without being connected to the end pattern, and the interval between these two patterns is adjusted as necessary. By doing so, the floating volume is adjusted.

[0010]

[Action]

 According to the present invention, the end pattern that forms the coil end of the inductor and the same pattern face each other via the magnetic material without connecting to the coil, so a small capacitance is obtained between them. The minute electrostatic capacitance can be changed by changing the distance between these opposing patterns. Therefore, the stray capacitance can be adjusted.

[0011]

【Example】

 1 is a basic laminated exploded perspective view showing a coil conductor pattern and a floating capacitance adjusting pattern in an inductor portion of a filter of the present invention, and FIG. 2 is a coil conductor pattern and an internal electrode pattern used in an embodiment of the present invention. FIG. 3 is a fragmentary perspective view showing a stacking order of a stacked body configured by using each pattern shown in FIG. 2, and will be described below with reference to these drawings.

(1) A polyvinyl butyral resin as a binder and toluene and ethanol as a solvent are added to a ferrite material composed of 49 mol% Fe ₂ O ₃ , 20 mol% ZnO, 20 mol% NiO, and 11 mol% CuO to form a slurry, and a doctor A magnetic green sheet having a thickness of 100 μm was formed by the blade method.

(2) Dielectric material composed of 95% by weight of TiO _{2, 2} % by weight of CuO and 3% by weight of NiO was used as a magnetic material to obtain a dielectric green sheet having a thickness of 100 μm.

(3) As shown in FIGS. 2A to 2E, through holes 3 are provided at predetermined positions of the magnetic green sheet 1 for electrical continuity between layers, and a coil conductor pattern 4 is screened with a paste containing Ag as a main component. A stray capacitance adjusting pattern 7 was prepared by the printing method (see FIGS. 1A to 1F), and the same pattern as the coil end pattern (FIG. 4F) having the lead-out portion 6 was prepared.

On the other hand, on the dielectric green sheet, as shown in FIGS. 2G and 2H, the internal electrode pattern 5 was formed with a paste containing Ag as a main component.

(4) After cutting the dielectric green sheet 2 and the magnetic green sheet 1 to a predetermined size, they are laminated as shown in the exploded perspective view of FIG. 3 (d is a dummy sheet), and 80 ° C. , 200 kg / cm ² when thermocompression-bonded and integrated into a laminated body, the same pattern as the end pattern F, which is the coil end portion, is not connected to the end pattern F and the end pattern and the magnetic material are interposed. And installed so that they face each other.

(5) After cutting the laminated body into chip elements, it was fired at 900 ° C. for 2 hours to obtain sintered body chips.

(6) A paste consisting of Ag and glass frit was applied to the sintered chip, baked at 800 ° C. to form external terminals, and further Ni-plated and solder-plated.

[0019]

[Effect of device]

 As described above, according to the laminated LC filter of the present invention, the same pattern as that of the end pattern forming the terminal end of the inductor portion is laminated via the magnetic substance without connecting to the coil. , By adjusting the interval between these patterns facing each other, it becomes easy to adjust the stray capacitance, which was difficult to control to a desired value in the past, which is extremely advantageous in designing the LC characteristics of the filter in advance. is there.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing a basic coil conductor pattern and a stray capacitance adjusting pattern in an inductor portion of a filter of the present invention.

FIG. 2 is a plan view showing a coil conductor pattern and an internal electrode pattern used in an embodiment of the present invention.

FIG. 3 is an exploded perspective view showing a stacking order of a stacked body configured by using each pattern shown in FIG.

[Explanation of symbols]

 1 Magnetic Green Sheet 2 Dielectric Green Sheet 3 Through Hole 4 Coil Conductor Pattern 5 Internal Electrode Pattern 6 Lead Out Part 7 Stray Capacitance Adjustment Pattern

Claims (1)

[Scope of utility model registration request] 1. A laminated inductor in which a coil conductor is internally provided in a magnetic ferrite body and a laminated capacitor in which positive and negative internal electrodes facing each other are internally provided in a dielectric ceramic body are integrally configured. In the laminated LC filter, a conductor having the same pattern as the end pattern conductor is not connected to the outside of the end pattern conductor forming the coil end portion of the inductor part as a part of the coil, and is simply magnetic. A laminated LC, which is provided so as to face the end pattern at a predetermined interval with the body interposed therebetween.
filter.