JP2007234755A - Lc composite filter component and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a steep insertion loss characteristic even in a higher frequency band than e.g. 100 MHz. <P>SOLUTION: The method for manufacturing the LC composite filter component comprising a coil conductor 25 and a first and second capacitor conductor wires 21, 22 has a sheet forming step of sintering a mixture of Ni-Zn ferrite grains with low-melting point glass grains to form insulation sheets 17a, 17b to be disposed between at least a plurality of coil conductor patterns 25a-25c. The ferrite grain has a mean grain size of 0.01-0.3 μm and a weight ratio of 5-40% to the total weight of the low-melting point glass grains. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing an LC composite filter component that functions as a filter for removing noise from electronic devices and the like, and an LC composite filter component.

As an anti-noise measure for electronic devices, an L-type, T-type, or π-type EMI (ElectroMagnetic Interference) filter is known in which an inductor (coil portion) and a capacitor (capacitor portion) are combined.
In recent years, even in such LC composite filter parts, with the downsizing of electronic equipment and the higher frequency of digital signals to be used, the high-frequency compatible small LC composite has a high cutoff frequency and excellent insertion loss characteristics at high frequencies. Filter parts have become desirable. In particular, in a mobile communication device such as a mobile phone, an LC composite filter component having an insertion loss characteristic capable of obtaining a large insertion loss in a high frequency band such as 100 MHz to 1 GHz and 2 GHz is desired.

Up to now, a small monolithic LC with a built-in filter circuit consisting of a coil conductor and a capacitor conductor using an insulating sheet formed of a mixed material obtained by mixing a magnetic material such as ferrite and a dielectric material such as glass. There are composite filter parts. Here, various types of mixed materials of ferrite and glass have been proposed (see, for example, Patent Documents 1 to 3).
JP-A-7-201552 JP-A-2-288307 Japanese Patent Laid-Open No. 3-74811

However, the conventional LC composite filter component has the following problems. That is, in the conventional LC composite filter component, for example, when a low-pass filter that can obtain a high insertion loss in a high-frequency band of 100 MHz or more is configured, the inductance of the coil portion in the low-frequency band is caused by the frequency dependence of the permeability of the ferrite. It gets bigger.
For this reason, there is a problem that the cut-off frequency is shifted to the low frequency side and a steep insertion loss characteristic cannot be obtained. Therefore, an insulating material used for the insulating material sheet is desired to have a low permeability and a high permeability in the high frequency band.

  The present invention has been made in view of the above-described problems. For example, an object of the present invention is to provide an LC composite filter component manufacturing method and an LC composite filter component capable of obtaining a steep insertion loss characteristic even in a high frequency band of 100 MHz or higher. And

  The present invention employs the following configuration in order to solve the above problems. That is, the manufacturing method of the LC composite filter component according to the present invention includes a coil conductor connected to a coil conductor pattern formed on each of a plurality of laminated insulating sheets, and a capacitor disposed oppositely through the insulating sheet. In a method of manufacturing an LC composite filter component comprising a capacitor conductor composed of a conductor pattern, a mixture of Ni-Zn ferrite particles and low melting point glass particles is sintered to form at least a plurality of coil conductor patterns. A sheet forming step of forming the insulating material sheet disposed on the ferrite particles, wherein the ferrite particles have an average particle size of 0.01 μm or more and 0.3 μm or less, and a weight ratio of 5 to the whole of the low-melting glass particles. % Or more and 40% or less.

In the present invention, the ferrite particles are coated with a low melting point glass to suppress the grain growth of the ferrite particles and to make each ferrite particle independent. For example, the ferrite particles have a high permeability even in a high frequency band of 100 MHz or more and the frequency of the permeability. An insulating material sheet with low dependency can be formed. By using this insulating material sheet, a steep insertion loss characteristic can be obtained even in a high frequency band.
That is, when a mixture of ferrite particles and low-melting glass particles is sintered, the molten low-melting glass particles cover each ferrite particle. Thereby, the grain growth by a ferrite particle couple | bonding with another ferrite particle at the time of sintering is suppressed. And since each ferrite particle exists independently in a sintered compact, the frequency dependence which is the variation | change_quantity of the magnetic permeability in the high frequency band of 100 MHz or more is suppressed, for example. Here, by setting the average particle diameter of the ferrite particles to 0.01 μm or more, it is possible to prevent the magnetic permeability from becoming too small in the low frequency band. In addition, when the average particle diameter of the ferrite particles is 0.3 μm or less, the frequency change of the magnetic permeability of the ferrite particles can be reduced, and at the same time, the mixing with the low melting point glass particles can be favorably performed. And by making the weight ratio with respect to the whole low melting glass particle 5% or more, it can prevent that each ferrite particle is reliably coat | covered with low melting glass after sintering, and the grain growth of a ferrite particle generate | occur | produces. Furthermore, the magnetic permeability can be prevented from becoming too small by setting the weight ratio of the low melting point glass particles to 40% or less.
Therefore, by forming the insulating sheet disposed at least between the coil conductor patterns with the above-described sintered body, the change in magnetic permeability is reduced even in the high frequency band, and a steep insertion loss characteristic is obtained in the high frequency band. .
In the present invention, the low melting point glass indicates a glass material having a softening point of 650 ° C. or lower.
Here, the weight ratio of the low-melting glass particles to the whole is desirably 20% or more and 30% or less. By doing in this way, each ferrite particle can be coat | covered reliably and a high magnetic permeability can be maintained.

In the method for producing an LC composite filter component of the present invention, the ferrite particles have a NiO content of 23 mol% to 42 mol%, a ZnO content of 1 mol% to 15 mol%, and a CuO content of 0 mol%. It is preferable that the blending ratio of Fe ₂ O ₃ is 47 mol% or more and 52 mol% or less.
In this invention, the mixing ratio of NiO is 23 mol% or more and 42 mol% or less, the mixing ratio of ZnO is 1 mol% or more and 15 mol% or less, the mixing ratio of CuO is 0 mol% or more and 20 mol% or less, and the mixing ratio of Fe ₂ O ₃ is 47 mol%. By setting it as 52 mol% or less above, the magnetic permeability of the insulating material sheet in a high frequency band can be made higher.

In the method for producing an LC composite filter part of the present invention, the low melting point glass particles have a Bi ₂ O ₃ content of 5 mol% to 40 mol%, a ZnO content of 5 mol% to 50 mol%, and B _2. It is preferable that the blending ratio of O ₃ is 30 mol% or more and 85 mol% or less.
In this invention, the stability of the low-melting glass can be maintained by setting the blending ratio of Bi ₂ O ₃ to 5 mol% or more. Moreover, the blending ratio of _Bi 2 _{O 3} is set to be lower than or equal 40 mol%, it is possible to prevent the insulation resistance of the insulating sheet is too small. And it can avoid that the softening point of a low melting glass becomes too high because the compounding rate of ZnO shall be 5 mol% or more and 50 mol% or less. Moreover, the blending ratio of B ₂ O ₃ With 30 mol% or more, it is possible to prevent the sintering temperature of the mixture of the ferrite particles is increased. _Then, the blending ratio of B 2 _{O 3} is set to be lower than or equal 85 mol%, it can be maintained waterproof insulating sheet.

Moreover, the LC composite filter component of the present invention is manufactured by the above-described LC composite filter component manufacturing method.
In the present invention, since it is manufactured by the above-described manufacturing method, the change in magnetic permeability is small even in the high frequency band, and a steep insertion loss characteristic is obtained in the high frequency band.

  According to the LC composite filter component manufacturing method and the LC composite filter component of the present invention, for example, an insulating material sheet having high magnetic permeability and low frequency dependence of magnetic permeability can be formed even in a high frequency band of 100 MHz or higher. A steep insertion loss characteristic can be obtained in the band.

  Hereinafter, an embodiment of an LC composite filter component according to the present invention will be described with reference to the drawings. In this embodiment, the present invention is applied to a three-terminal type noise filter. FIG. 1 is an exploded perspective view of an LC composite filter component in the present embodiment, FIG. 2 is an external perspective view, and FIG. 3 is an equivalent circuit diagram.

The LC composite filter component 10 is a low-pass filter that removes a signal or noise having a frequency higher than the cut-off frequency, and has a configuration in which nine layers of insulating sheets are laminated and integrated. Further, on the two opposing side surfaces of the LC composite filter component 10 formed as a substantially rectangular parallelepiped laminate, external electrodes 11 connected to a coil conductor 25 described later and first and second capacitor conductors 21, 22 described later, 12 are provided, and external electrodes 13 and 14 connected to the first and second capacitor conductors 21 and 22 are provided on the other two opposite side surfaces of the LC composite filter component 10.
Further, a laminated body in which nine insulating material sheets are laminated and integrated is a first cover layer (insulating material sheet) 15, a first capacitor layer 16, a coil layer 17, a second capacitor layer 18, and a second cover layer. (Insulating material sheet) 19 is laminated in this order.

The 1st and 2nd cover layers 15 and 19 are provided in order to protect the 1st and 2nd capacitor layers 16 and 18 and the coil layer 17, and are constituted by one sheet of insulating material, respectively.
Here, the insulating material sheet which comprises the 1st and 2nd cover layers 15 and 19 is comprised by the sintered compact which coat | covered the Ni-Zn type ferrite particle with the low melting glass. The ferrite particles have a NiO (nickel oxide) content of 23 mol% to 42 mol%, a ZnO (zinc oxide) content of 1 mol% to 15 mol%, and a CuO (copper oxide) content of 0 mol% or more. The blending ratio of 20 mol% or less and Fe ₂ O ₃ (ferrous dioxide) is 47 mol% or more and 52 mol% or less, and the average particle diameter is 0.01 μm or more and 0.3 μm or less. In addition, the low melting point glass has a Bi ₂ O ₃ (bismuth oxide) content ratio of 5 mol% to 40 mol%, a ZnO content ratio of 5 mol% to 50 mol%, and a B ₂ O ₃ (boron oxide) content ratio. It is 30 mol% or more and 85 mol% or less. In the present embodiment, the low melting point glass indicates a glass material having a softening point of 650 ° C. or lower.
Note that the first and second cover layers 15 and 19 are not limited to the above-described one layer, and may be two or more layers.

  Each of the first and second capacitor layers 16 and 18 has a structure in which two insulating material sheets 16a and 16b and insulating material sheets 18a and 18b are laminated in two layers in order from the upper surface side. Here, the insulating material sheets 16a and 16b and the insulating material sheets 18a and 18b constituting the first and second capacitor layers 16 and 18 are formed of Ni-Zn ferrite as in the case of the first and second cover layers 15 and 19. It is comprised with the sintered compact which coat | covered particle | grains with the low melting glass.

  Capacitor conductor patterns 21a, 21b, 22a, and 22b are formed on the upper surfaces of the insulating material sheets 16a, 16b, 18a, and 18b, respectively. These capacitor conductor patterns 21a, 21b, 22a, and 22b are formed by using a known method such as printing or plating with a conductor such as silver.

Among these, the capacitor conductor pattern 21a is a substantially rectangular conductor pattern, and is formed on the upper surface of the insulating material sheet 16a. The lead electrodes 23a and 23b connected to the external electrodes 13 and 14 are formed on the pair of side sides of the capacitor conductor pattern 21a, respectively.
The capacitor conductor pattern 21b is a substantially rectangular conductor pattern, and is formed on the upper surface of the insulating material sheet 16b. An extraction electrode 23c connected to the external electrode 12 is formed on one end side of the capacitor conductor pattern 21b.
Here, the capacitor conductor patterns 21a and 21b are formed so as to overlap each other in a top view. Then, the capacitor conductor patterns 21a and 21b are arranged to face each other via the insulating material sheet 16a, whereby the first capacitor conductor 21 shown in FIGS. 1 and 3 is configured.

The capacitor conductor pattern 22a is a substantially rectangular conductor pattern, and is formed on the upper surface of the insulating material sheet 18a. An extraction electrode 24a connected to the external electrode 12 is formed on one end side of the capacitor conductor pattern 22a.
The capacitor conductor pattern 22b is a substantially rectangular conductor pattern, and is formed on the upper surface of the insulating material sheet 18b. The lead electrodes 24b and 24c connected to the external electrodes 13 and 14 are formed on the pair of side sides of the capacitor conductor pattern 22b, respectively.
Here, the capacitor conductor patterns 22a and 22b are formed so as to overlap each other in a top view. The capacitor conductor patterns 22a and 22b are arranged to face each other via the insulating material sheet 18a, whereby the second capacitor conductor 22 shown in FIGS. 1 and 3 is configured.

  The coil layer 17 is configured by laminating three insulating material sheets 17a to 17c in order from the upper surface side. Here, the insulating sheet 17a-17c which comprises the coil layer 17 is comprised by the sintered compact which coat | covered the Ni-Zn type ferrite particle with the low melting glass similarly to the above-mentioned.

  Coil conductor patterns 25a to 25c are formed on the upper surfaces of the insulating material sheets 17a to 17c, respectively. Similar to the capacitor conductor patterns 21a, 21b, 22a, and 22b, the coil conductor patterns 25a to 25c are formed by, for example, a conductor such as silver by a known method such as printing or plating.

  Among these, the coil conductor pattern 25a is a substantially U-shaped conductor pattern, and is formed on the upper surface of the insulating material sheet 17a. An extraction electrode 26a connected to the external electrode 12 is formed at one end of the coil conductor pattern 25a. The other end of the coil conductor pattern 25a is connected to the coil conductor pattern 25b formed on the upper surface of the insulating material sheet 17b through a through hole Ha provided so as to penetrate the insulating material sheet 17a. .

  The coil conductor pattern 25b is a substantially U-shaped conductor pattern and is formed on the insulating material sheet 17b. And one end part of the coil conductor pattern 25b is connected to the coil conductor pattern 25a formed on the insulating material sheet 17a mentioned above through the through hole Ha. The other end of the coil conductor pattern 25b is connected to a coil conductor pattern 25c formed on the upper surface of the insulating sheet 17c through a through hole Hb provided so as to penetrate the insulating sheet 17b. .

The coil conductor pattern 25c is a substantially U-shaped conductor pattern and is formed on the upper surface of the insulating material sheet 17c. An extraction electrode 26b connected to the external electrode 11 is formed at one end of the coil conductor pattern 25c. The other end of the coil conductor pattern 25c is connected to the coil conductor pattern 25b formed on the insulating material sheet 17b described above through the through hole Hb.
Here, the coil conductor patterns 25a to 25c are electrically connected to form the coil conductor 25 shown in FIGS.

  As shown in FIG. 3, the LC composite filter component 10 configured in this way has an L-shaped noise in which the first and second capacitor conductors 21 and 22 connected to the ground are provided at the output end of the coil conductor 25. Configure the filter.

The manufacturing method of the LC composite filter component 10 of the present invention configured as described above will be described below.
First, a sheet forming process for forming an insulating material sheet constituting the first and second cover layers 15 and 19, the first and second capacitor layers 16 and 18, and the coil layer 17 is performed. This first forms a mixture of Ni—Zn ferrite particles and low melting glass particles.

That is, NiO, ZnO, CuO, and Fe ₂ O ₃ which are Ni—Zn-based ferrite oxide raw materials are mixed at a proportion of 23 mol% to 42 mol%, 1 mol% to 15 mol%, 0 mol% to 20 mol%, respectively. Then, it mix | blends and mixes so that it may become 47 mol% or more and 52 mol% or less. Then, the mixture of these oxide raw materials is dried and then sintered at 1000 ° C., for example. Thereafter, the sintered product is ball milled with zirconia balls using ethanol as a medium. Thereby, ferrite particles in a slurry state with an average particle diameter of 0.01 μm or more and 0.3 μm or less are formed. The particle size of the ferrite particles is controlled by appropriately adjusting the milling time.

Further, Bi ₂ O ₃ , ZnO, and B ₂ O ₃ which are oxide raw materials for low-melting glass are mixed at 5 to 40 mol%, 5 to 50 mol%, and 30 to 85 mol%, respectively. Mix and mix so that Then, a mixture of these oxide raw materials is melted at 1000 ° C., for example, and then rapidly cooled and coarsely pulverized. Thereafter, the coarsely pulverized low melting point glass is ball milled under the same conditions as the ferrite particles described above. Thereby, low melting glass particles in a slurry state are formed. Here, the average particle size of the low-melting glass particles is desirably 0.5 to 4 times the average particle size of the ferrite particles. Thereby, mixing with a ferrite particle and a low melting glass particle is performed uniformly. The particle size of the low-melting glass particles is controlled by appropriately adjusting the milling time in the same manner as the ferrite particles.

  Next, the formed ferrite particles in the slurry state and the low melting glass particles are mixed and dried to form a mixture of the ferrite particles and the low melting glass particles. Here, the low melting point glass particles are mixed so that the weight ratio is 5% or more and 40% or less with respect to the mixture of the ferrite particles and the low melting point glass particles. As described above, a mixture in which ferrite particles and low-melting glass particles are mixed is formed.

  Subsequently, an organic binder, an organic solvent, and a dispersing agent are added to the obtained mixture, and a green sheet is created by a doctor blade method to produce an insulating material sheet having a predetermined shape (for example, a rectangular shape). Here, the sintering temperature of the insulating material sheet is desirably 900 ° C. or lower, for example, 850 ° C. At this time, the low melting point glass particles arranged around the ferrite particles are melted to coat the ferrite particles. Thereby, it is suppressed that a ferrite particle couple | bonds and grain growth. The insulating material sheet is formed as described above.

Then, through holes Ha and Hb are provided at predetermined positions of the insulating material sheets 17a and 17b constituting the coil layer 17 by using a well-known method such as laser and punching.
Next, the capacitor conductor patterns 21a, 21b, 22a, and 22b are short-circuited to each other on the upper surfaces of the insulating material sheets 16a, 16b, 18a, and 18b by using a known method such as printing or transfer using a conductive paste such as silver. Form so as not to. Similarly, the coil conductor patterns 25a to 25c are formed on the upper surfaces of the insulating material sheets 17a to 17c so as not to short-circuit each other.
At this time, extraction electrodes 23a and 23b are provided at the end sides of the capacitor conductor pattern 21a, extraction electrodes 23c are provided at the end sides of the capacitor conductor pattern 21b, and extraction electrodes 24a are provided at the end sides of the capacitor conductor pattern 22a. Extraction electrodes 24b and 24c are formed on the end side of 22b, an extraction electrode 26a is formed on one end of the coil conductor pattern 25a, and an extraction electrode 26b is formed on one end of the coil conductor pattern 25c. .
In addition, the through holes Ha and Hb are filled with a conductive material such as silver which is integrally continuous with the conductor pattern formed on the insulating material sheet provided with the through holes. Note that the conductor pattern formed on the insulating material sheet connected through the through-hole is electrically contacted with the conductor of the through-hole by providing a convex electrode portion (not shown) on the conductor pattern side. To be connected to.

  Next, the 1st cover layer 15, insulating material sheet 16a, 16b, 17a-17c, 18a, 18b, and the 2nd cover layer 19 are laminated | stacked, and a laminated body is formed by thermocompression-bonding with a press. And this is sintered at 900 degreeC, the external electrodes 11-14 are formed using silver, and it completes by forming a plating film with Ni (nickel) and Sn (tin).

The LC composite filter component 10 configured in this way can form an insulating material sheet having a high magnetic permeability even in a high frequency band of, for example, 100 MHz or more and having a low frequency dependency of the magnetic permeability. Characteristics are obtained.
Here, by setting the average particle diameter of the ferrite particles to 0.01 μm or more, the magnetic permeability does not become too small in the low frequency band in the low frequency band. Further, by making the average particle size of the ferrite particles 0.3 μm or less, the frequency change of the permeability of the ferrite particles can be reduced, and at the same time, the ferrite particles can be mixed well with the low melting point glass particles. And by making the weight ratio with respect to the whole low melting glass particle 5% or more, a ferrite particle can be reliably coat | covered with low melting glass, and generation | occurrence | production of the grain growth of a ferrite particle can be suppressed. Furthermore, it can prevent that the magnetic permeability of a sheet | seat material becomes too small because the weight ratio with respect to the whole low melting glass particle shall be 40% or less.

Moreover, the mixing ratio of NiO in the ferrite particles is 23 mol% or more and 42 mol% or less, the mixing ratio of ZnO is 1 mol% or more and 15 mol% or less, the mixing ratio of CuO is 0 mol% or more and 20 mol% or less, and the mixing ratio of Fe ₂ O ₃ is 47 mol. % Or more and 52 mol% or less, the magnetic permeability of the sheet material is relatively high (for example, the relative magnetic permeability is 3 to 5).
Moreover, the blending ratio of Bi ₂ O ₃ of low-melting glass by a 5 mol% or more, the stability of the low melting point glass is maintained. Then, the blending ratio of _Bi 2 _{O 3} is set to be lower than or equal 40 mol%, the insulation resistance of the sheet material is maintained. Furthermore, it can avoid that the softening point of a low melting glass becomes high too much by making the compounding ratio of ZnO 5 mol% or more and 50 mol% or less. In addition, by setting the blending ratio of B ₂ O ₃ to 30 mol% or more, it is possible to prevent the sintering temperature of the mixture of the low melting point glass and the ferrite particles from increasing. _Then, the blending ratio of B 2 _{O 3} is set to be lower than or equal 85 mol%, it can be maintained the water resistance of the sheet material.
Moreover, since the average particle diameter of the low melting point glass particles is 0.5 to 4 times the average particle diameter of the ferrite particles, the ferrite particles and the low melting point glass particles are uniformly mixed.

Next, the LC composite filter component according to the present invention will be specifically described with reference to examples.
First, the insulating material sheets of Examples 1 to 10 and Comparative Examples 1 to 5 were formed using ferrite particles and glass particles as shown in Table 1 below. And the relative magnetic permeability in 10 MHz and 1 GHz of each insulating material sheet was measured. The results are shown in Table 1.
Here, in Table 1, the compositions F1 and F2 of ferrite are the compositions shown in Table 2, respectively, and the compositions G1 to G3 of the low melting glass are the compositions shown in Table 3, respectively. Moreover, the sintering temperature has shown the temperature at the time of sintering the mixture of a ferrite particle and a low melting glass particle.

As shown in Table 1, the average particle diameter of the ferrite particles is 0.01 μm or more and 0.3 μm or less, and the weight ratio of the low melting point glass to the entire mixture is 5% or more and 40% or less, so that the frequency is 100 MHz or more. It was confirmed that the high magnetic permeability (for example, 3 to 5) in the high frequency band can be reduced and the frequency dependence of the relative permeability can be reduced.
In Comparative Example 4, the average particle size of the low melting point glass was 0.6 μm, which was larger than 4 times the average particle size of the ferrite particles, and therefore generation of large pores was confirmed.

  In addition, L-type composite filter components having the same coil conductor and capacitor conductor were formed using the insulating material sheets of Example 3 and Comparative Example 1, and the frequency characteristics of the insertion loss were obtained. The results are shown in FIGS. 4 and 5, respectively. 4 and 5, by using an insulating material sheet having a high relative permeability in a high frequency band of 100 MHz or higher and having a small frequency dependency of the relative permeability, the insertion frequency has a cut-off frequency in the high frequency band and a steep insertion loss. It was confirmed that characteristics were obtained.

In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.
For example, the above-described LC composite filter component has a ferrite particle NiO content of 23 mol% to 42 mol%, a ZnO content of 1 mol% to 15 mol%, a CuO content of 0 mol% to 20 mol%, Fe _Although the blending ratio of ₂ O ₃ is 47 mol% or more and 52 mol% or less, other blending ratios and compositions may be used as long as they are Ni—Zn ferrite particles exhibiting high magnetic permeability in a high frequency band.
Similarly, the blending ratio of Bi ₂ O ₃ in the low melting point glass is 5 mol% or more and 40 mol% or less, the blending ratio of ZnO is 5 mol% or more and 50 mol% or less, and the blending ratio of B ₂ O ₃ is 30 mol% or more and 85 mol% or less. However, if the ferrite particles can be densely and uniformly dispersed during the sintering of the mixture with the ferrite particles and each ferrite particle can be coated, other blending ratios and compositions may be used.

Further, the insulating material sheet and the first and second cover layers arranged between the capacitor conductor patterns constituting the capacitor conductor are made of a mixture of ferrite and low melting point glass, but at least the coil constituting the coil conductor The insulating material sheet | seat arrange | positioned between conductor patterns should just be comprised with the said mixture, and may be comprised with another insulating material.
Moreover, although it has the structure which has a 1st and 2nd capacitor | condenser conductor, it is good also as a structure which has only one capacitor | condenser conductor, and a structure which has three or more capacitor | condenser conductors.
Moreover, although it is an L-type LC composite filter part, it may be an LC composite filter part having another configuration such as a T-type or a π-type.
Further, although the coil conductor has a spiral shape, it may have another shape such as a meander shape.
It is also possible to arrange a plurality of sets having the above-described configuration into an array.

It is a disassembled perspective view which shows LC composite filter components in one Embodiment of this invention. It is an external appearance perspective view which shows LC composite filter component of FIG. FIG. 2 is an equivalent circuit diagram illustrating the LC composite filter component of FIG. 1. It is a graph which shows the frequency characteristic of the insertion loss of LC composite filter components in an Example. Similarly, it is a graph which shows the frequency characteristic of the insertion loss of LC composite filter components in a comparative example.

Explanation of symbols

10 LC composite filter component 15 First cover layer (insulating material sheet)
16a, 16b, 17a-17c, 18a, 18b Insulating material sheet 19 Second cover layer (insulating material sheet)
21 First capacitor conductor (capacitor conductor)
21a, 21b, 22a, 22b Capacitor conductor pattern 22 Second capacitor conductor (capacitor conductor)
25 Coil conductors 25a to 25c Coil conductor pattern

Claims (4)

LC composite filter comprising: a coil conductor connecting coil conductor patterns formed on each of a plurality of laminated insulating sheets; and a capacitor conductor composed of capacitor conductor patterns arranged opposite to each other via the insulating sheet In the manufacturing method of parts,
Sintering a mixture of Ni-Zn ferrite particles and low melting point glass particles, and forming a sheet forming step of forming the insulating material sheet disposed between at least the coil conductor patterns;
Production of an LC composite filter part, wherein the ferrite particles have an average particle size of 0.01 μm or more and 0.3 μm or less, and a weight ratio of the low melting point glass particles to the whole of 5% or more and 40% or less. Method. The ferrite particles have a NiO content of 23 mol% to 42 mol%, a ZnO content of 1 mol% to 15 mol%, a CuO content of 0 mol% to 20 mol%, and a Fe ₂ O ₃ content of 47 mol. The method for producing an LC composite filter component according to claim 1, wherein the production method is LC% or more and 52 mol% or less. The low melting point glass particles have a Bi ₂ O ₃ content of 5 mol% to 40 mol%, a ZnO content of 5 mol% to 50 mol%, and a B ₂ O ₃ content of 30 mol% to 85 mol%. The method for producing an LC composite filter component according to claim 1 or 2, wherein An LC composite filter component manufactured by the method for manufacturing an LC composite filter component according to any one of claims 1 to 3.

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