CN217562386U - Ceramic-inorganic material composite and multilayer inductor - Google Patents

Abstract

The utility model relates to a pottery-inorganic material complex and multilayer inductor, multilayer inductor includes a plurality of magnetic layers and the metal electrode track that forms on the magnetic layer, wherein, in the magnetic core region of the coil pattern that the metal electrode track formed, is provided with pottery-inorganic material complex, pottery-inorganic material complex contains more than two first layers and second layers, the first layer contains the ceramic material that the curve slope of dielectric constant along with the change in temperature is the positive number, the second layer contains the inorganic material that the curve slope of dielectric constant along with the change in temperature is the negative number, and first layer and second layer range upon range of each other with alternating mode; and the arrangement mode of the metal electrode tracks minimizes the dead space between two adjacent metal electrode tracks without magnetic lines of force. The utility model discloses a stable device characteristic can be realized to the multilayer inductor to strengthen its inductance performance.

Description

Ceramic-inorganic material composite and multilayer inductor

Technical Field

The utility model relates to an electron device field particularly, relates to a multilayer inductor structure body for power is used, particularly, multilayer inductor is used for power transmission's voltage current transformation, the impedance match of data transmission and processing, and electromagnetic interference's filtration.

Background

As one of the passive devices, the inductor can be generally classified as: a winding type inductor manufactured by winding a coil around a ferrite core and forming electrodes at both ends thereof; a multilayer type inductor is manufactured by printing internal electrodes on magnetic layers or dielectric layers and then stacking the magnetic layers or dielectric layers.

In recent years, due to thick film printing processes and LTCC material development, further miniaturization of passive devices such as resistors, capacitors, and inductors is required. As a solution to the optimum SMT inductor for size miniaturization and low cost in a small-sized circuit board, a multilayer type inductor is gradually gaining prominence as compared with a winding type inductor.

Generally, a multilayer inductor is a single monolithic structure formed by a high-temperature solid-phase reaction of a multilayer body composed of a plurality of magnetic sheets (or tapes). The magnetic sheet may be printed (but not limited to) with conductive electrodes as a coil pattern. As technology has evolved, there has been extensive research in the prior art to improve multilayer inductor structures.

In this regard, US 6249205B proposes a multilayer inductor which provides high inductance by introducing an air gap between the layers of the multilayer inductor. However, such air gaps can cause performance fluctuation problems for the inductor.

Thus, the weakness of multilayer inductors, i.e. inductance and impedance instability under different application conditions such as current, frequency, temperature etc., has not been addressed in the art to date.

SUMMERY OF THE UTILITY MODEL

Technical problem

On the one hand, generally, when preparing the body, non-magnetic ceramics are chosen in the art to adjust the characteristics of the inductor and its stability instead of the air gap. However, there is a problem in that the characteristics of these nonmagnetic ceramics also deviate depending on the temperature and frequency. In this connection, the applicant found that the root cause of instability of the non-magnetic ceramic at the gap position of the core region to current, temperature and frequency is a dielectric constant deviation.

Accordingly, it is a technical object of the present invention to provide a ceramic-inorganic material composite body filling such gap positions, which can eliminate the deviation of the dielectric constant of the magnetic core with current, temperature and frequency, thereby realizing a multilayer inductor structure with stable characteristics.

On the other hand, in the prior art, the multilayer inductor is manufactured by printing metal electrode tracks on a magnetic sheet, and then co-firing the magnetic sheet by static pressing, and therefore, the thickness of the magnetic sheet is not necessarily too small in consideration of the workability of the manufacturing process. Therefore, there is a high proportion of dead space between the metal electrode tracks of adjacent layers where there is no effective magnetic field line and thus does not contribute to the inductor performance. The applicant finds that the dead space can be compressed to the maximum extent by reducing the space between the metal electrode tracks of two adjacent layers or changing the arrangement mode of the metal electrode tracks.

Therefore, another technical object of the present invention is to provide a multilayer inductor, which can minimize dead space without effective magnetic lines of force, thereby enhancing the characteristics of the multilayer inductor, such as enhancing the effective magnet utilization of the multilayer inductor, thereby enhancing the characteristics of the inductor, for example, the inductance value of the inductor is increased, the current stability is improved, and the impedance characteristics are optimized.

Technical scheme

In order to solve the above technical problems, in one aspect, the present invention provides a ceramic-inorganic material composite body for a multilayer inductor, which is located in a magnetic core region of a metal electrode track existing in a coil pattern, and which comprises two or more first layers comprising a ceramic material having a positive slope of a curve of a dielectric constant with temperature, and a second layer comprising an inorganic material having a negative slope of a curve of a dielectric constant with temperature, and which is stacked on each other in an alternating manner.

In this respect, the ceramic material having a positive slope of the dielectric constant versus temperature curve may be almost any ceramic material commonly used in the art, for example selected from commercially available materials such as titanium dioxide, zirconium dioxide, and the like.

The ceramic material with negative slope of the curve of the dielectric constant changing along with the temperature can be selected from commercial materials, such as calcium carbonate, calcium bicarbonate, calcium oxide and the like.

The metal electrode includes silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), gold (Au), nickel (Ni), or an alloy thereof or a composite thereof.

In this aspect, there is also provided a multilayer inductor including a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein, in a magnetic core region of a coil pattern formed by the metal electrode tracks, a ceramic-inorganic material composite is provided, the ceramic-inorganic material composite including two or more first layers and second layers, the first layers including a ceramic material having a positive slope of a curve of a dielectric constant with temperature change, the second layers including a ceramic material having a negative slope of a curve of a dielectric constant with temperature change, and the first layers and the second layers being laminated on each other in an alternating manner.

In a second aspect, the present invention provides a multilayer inductor, which includes a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein the metal electrode tracks are arranged in such a manner that an invalid space between two adjacent metal electrode tracks where no effective magnetic line of force exists is minimized.

According to a second aspect, the metal electrode tracks are arranged in the manner: the multilayer metal electrode tracks of the multilayer inductor are closely arranged in the vertical direction so that the overall thickness of the magnetic layer between the metal electrode tracks is 10 μm or less.

In a second aspect, the plurality of magnetic layers and the metal electrode tracks are formed by printing, etching, laser, and the like. Wherein, when a plurality of magnetic layers and metal electrode tracks are formed by a multiple printing technique, the thickness of the magnetic layer or the metal layer printed each time is 5 μm or less.

According to the second aspect, the metal electrode tracks are alternatively arranged in a manner that: the multi-layer metal electrode tracks of the multi-layer inductor are arranged with step-like mismatches in a cross-section perpendicular to the plurality of magnetic layers.

Specifically, the metal electrode tracks of the upper layer are mismatched left or right stepwise with respect to the metal electrode tracks of the lower layer.

The material of the magnetic layer may be a ferrite material.

In a third aspect, the present invention provides a multilayer inductor comprising a plurality of magnetic layers and a metal electrode track formed on the magnetic layers, wherein a ceramic-inorganic material composite is provided in a magnetic core region of a coil pattern formed by the metal electrode track, the ceramic-inorganic material composite comprising two or more first layers and second layers, the first layers comprising a ceramic material having a positive slope of a curve of a change in dielectric constant with temperature, the second layers comprising an inorganic material having a negative slope of a curve of a change in dielectric constant with temperature, and the first and second layers being stacked on each other in an alternating manner; and the arrangement mode of the metal electrode tracks minimizes the dead space between two adjacent metal electrode tracks without effective magnetic lines.

Advantageous effects

According to the first aspect of the present invention, the ceramic-inorganic material composite body or the multilayer inductor can eliminate the deviation of the dielectric constant of the magnetic core with current, temperature and frequency, thereby realizing a multilayer inductor structure with stable characteristics.

According to the second aspect of the present invention, the dead space between the metal electrode tracks of the multilayer inductor is reduced to the maximum, thereby increasing the magnetic capacity available for the magnetic core and reducing the DC resistance.

In addition, by closely arranging the metal electrode tracks, the deformation, cracking and unstable reliability of products caused by delamination or anisotropy of machine shrinkage rate in subsequent processes (such as sintering) can be avoided.

According to the utility model discloses a third aspect, multilayer inductor can improve the electricity and the magnetism nature performance of device when realizing stable characteristic to strengthen multilayer inductor's effectual magnet utilization ratio, thereby strengthen the characteristic of inductance. For example, the inductance value is improved, the current stability is improved, and the impedance characteristic is optimized.

Drawings

The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.

FIG. 1A is a schematic perspective view of a prior art multilayer inductor structure;

FIG. 1B is a schematic cross-sectional view of a prior art multilayer inductor structure;

fig. 2A is a schematic cross-sectional view of a ceramic-inorganic material composite body of the present invention;

fig. 2B is a schematic cross-sectional view of a multilayer inductor structure comprising a ceramic-inorganic material ceramic composite of the present invention;

FIG. 3 is a schematic cross-sectional view of the dead space of a prior art multilayer inductor structure;

fig. 4A is a schematic cross-sectional view of a multilayer inductor structure of the present invention comprising closely spaced multilayer metal electrode tracks;

FIG. 4B is an enlarged partial view of the structure of FIG. 4A formed using a multiple printing technique;

fig. 4C is a schematic cross-sectional view of a multilayer inductor structure formed by the mismatch of multilayer metal electrode tracks and the magnetic line of force distribution therein of the present invention;

FIG. 5 shows the impedance-frequency curve of the multilayer inductor obtained in example 1;

fig. 6 shows an inductance-current curve of the multilayer inductor obtained in example 1;

fig. 7A shows a schematic diagram of effective magnetic flux lines of the multilayer inductor obtained in comparative example 1;

fig. 7B shows a schematic diagram of effective magnetic flux lines of the multilayer inductor obtained in example 1;

fig. 8 shows an inductance-current curve of the multilayer inductor obtained in example 3.

Detailed Description

Hereinafter, the present invention will be described in more detail.

It should be understood that the terms used in the specification and claims may be interpreted as having a meaning consistent with their meaning in the context of the relevant art and the technical idea of the present invention, on the basis of the principle which the inventor may appropriately define. The terminology used in the description is for the purpose of illustrating exemplary embodiments only and is not intended to be limiting of the invention.

It will be further understood that the terms "comprises," "comprising," or "having," when used in this specification, specify the presence of stated features, integers, steps, elements, or groups thereof, but do not preclude the presence or addition of one or more other features, integers, steps, elements, or groups thereof.

In describing the structure of an element herein with reference to the drawings, in describing the positional relationship of certain components, "upper", "lower", "upper layer", "lower layer", and the like refer to the relative positional relationship of the components, and are not limited to the structure shown in the drawings.

The multilayer inductor of the present invention is described in detail below.

Referring first to fig. 1A, a schematic perspective view of a prior art multilayer inductor structure is shown. A multilayer inductor or multilayer inductor structure 100 includes a plurality of magnetic layers 101, and a plurality of metal electrode tracks 102 formed on the plurality of magnetic layers. The metal electrode tracks formed in the single magnetic layer are in a coil pattern. In the center of the coil pattern, corresponding to the "magnetic core area" 103 of the present invention.

In this regard, reference is made to fig. 1B, which shows a schematic cross-sectional view (partial) of a prior art multilayer inductor structure, wherein like components are shown with like reference numerals. As can be seen in fig. 1B, the "core region" described herein refers to the central region surrounded by the coil.

The ceramic-inorganic material composite of the present invention may be located at any position of the magnetic core region 103, such as the position shown in the black bar region of fig. 1B.

As described above, in a first aspect, there is provided a ceramic-inorganic material composite for a multilayer inductor, which is located in a magnetic core region of a metal electrode track existing in a coil pattern, and which comprises two or more first layers comprising a ceramic material having a positive slope of a curve of a change in dielectric constant with temperature, and second layers comprising an inorganic material having a negative slope of a curve of a change in dielectric constant with temperature, and the first and second layers are laminated on each other in an alternating manner.

In this regard, reference is made to fig. 2A, which shows a schematic cross-sectional view of a ceramic-inorganic material composite body of the present invention. The ceramic-inorganic material composite 200 includes two layers, a first layer 201 including a ceramic material having a positive slope of a dielectric constant change with temperature, and a second layer 202 including an inorganic material having a negative slope of a dielectric constant change with temperature.

Here, the "slope of a curve of a dielectric constant with temperature" has the following meaning: in the graph of the change of the dielectric constant with the temperature, the change rate of the dielectric constant of the material with the temperature is larger or smaller, if the change rate is larger, the slope is positive, and vice versa.

Preferably, the slope of the ceramic material with the positive slope of the curve of the dielectric constant variation with temperature is between 0.1 and 1; the slope of the inorganic material with the negative slope of the curve of the change of the dielectric constant along with the temperature is-0.1 to 0.05.

Although only the ceramic-inorganic material composite having a two-layer structure is shown in fig. 2A. However, the ceramic-inorganic material composite of the present invention may include two or more first layers and second layers, and when two or more first layers and second layers are included, the first layers and the second layers are stacked on each other in an alternating manner, i.e., in the manner of first layer/second layer/first layer \8230;, etc.

The ceramic-inorganic material composite shown in fig. 2A may be located at any position of the core region of the multilayer inductor, such as the black stripe position of the core region 103 shown in fig. 1B.

After the core region of the multilayer inductor is embedded, the ceramic material having a positive slope of a curve of a change in permittivity with temperature and the inorganic material having a negative slope of a curve of a change in permittivity with temperature are overlapped with each other, so that a deviation of the permittivity of the core with current, temperature and frequency is eliminated, thereby realizing a multilayer inductor structure having stable characteristics.

In a first aspect, there is also provided a multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein, in a magnetic core region of a coil pattern formed by the metal electrode tracks, a ceramic-inorganic material composite is provided, the ceramic-inorganic material composite comprising two or more first layers and second layers, the first layers comprising a ceramic material whose slope of a curve of a change in dielectric constant with temperature is a positive number, the second layers comprising an inorganic material whose slope of a curve of a change in dielectric constant with temperature is a negative number, and the first layers and the second layers being laminated on each other in an alternating manner.

Fig. 2B shows a schematic cross-sectional view of a multilayer inductor structure comprising the ceramic-inorganic material composite body of the present invention. In the multilayer inductor 300, the ceramic-inorganic material composite 200 including a plurality of first and second layers is disposed in the core region. In this regard, as described above, the ceramic-inorganic material composite body 200 may be located at any position of the magnetic core region, and is not limited to the position shown in fig. 2B.

In this respect, almost all of the commonly used ceramic materials in the art are materials having a positive slope of a curve of a change in dielectric constant with temperature, and thus can be used as the ceramic material herein. In general, the ceramic material having a positive slope of the dielectric constant with temperature may be a commercially available material such as titanium dioxide, zirconium dioxide, etc.

The inorganic material having a negative slope of the dielectric constant curve with respect to temperature may be commercially available materials such as calcium carbonate, calcium bicarbonate, calcium oxide, and the like.

The metal electrode includes silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), gold (Au), nickel (Ni), or an alloy thereof or a composite thereof.

The material of the magnetic layer may be a magnetic material, i.e. a ceramic material with magnetic properties, mainly a ferrite material, preferably a nickel zinc copper ferrite material. For example, the ferrite powder includes iron oxide powder, zinc oxide powder, copper oxide powder, nickel oxide powder, bismuth oxide powder, and a small amount of silicon oxide powder, as examples.

The preparation method of the ceramic-inorganic material complex of the utility model is as follows:

respectively dissolving a ceramic material (and an optional modifier) with a positive slope of a curve of which the dielectric constant changes with the temperature and an inorganic material (and an optional modifier) with a negative slope of a curve of which the dielectric constant changes with the temperature into a solvent, and dispersing to obtain slurry A containing the ceramic material with the positive slope of the curve of which the dielectric constant changes with the temperature and slurry B containing the inorganic material with the negative slope of which the dielectric constant changes with the temperature; and then alternately applying the slurry A and the slurry B on the substrate, and sintering at high temperature to obtain the ceramic-inorganic material composite.

In the above preparation method, the solvent used may be selected from ethyl cellulose and terpineol.

In the above-mentioned production method, the ceramic material and the inorganic material used are as described above.

In the above preparation method, the purpose of adding the modifier is to change the surface energy and activity of the slurry particle surface, so that the resultant is not easy to agglomerate to affect the processing quality. The modifier is preferably M1159 material of ferrio, and preferably, the modifier is stirred with a ceramic material or an inorganic material and then added with a solvent.

In the above preparation method, the dispersion process is carried out for 3 to 5 hours, for example, 4 hours using a ball mill.

In the above production method, the substrate is a magnetic substrate of a magnetic layer used for the multilayer inductor.

In the above-described manufacturing method, the pastes a and B are alternately printed on the substrate by an alternate printing process.

In the above-mentioned preparation method, the temperature of the high-temperature sintering is 800 ℃ to 950 ℃, for example, 900 ℃, and the time may be a suitable time commonly used in the art.

In a second aspect, there is provided a multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein the metal electrode tracks are arranged in such a manner that an ineffective space between adjacent two metal electrode tracks where no effective magnetic field lines exist is minimized.

Referring to fig. 3, a multilayer inductor 400 includes a plurality of magnetic layers 101 and metal electrode tracks 102 formed thereon. The plurality of metal electrode tracks 102 are arranged substantially in parallel. Since the magnetic tape used to form the magnetic layer has a large thickness, typically 100 μm or more, there is a large space between the metal electrode tracks 102 of the adjacent two layers. In this space, the applicants have found that there is no contribution to the performance of the device due to the absence of effective magnetic flux lines therein when the device is in use; therefore, such a space between the metal electrode tracks 102 of the adjacent two layers where no magnetic field lines exist is referred to as "dead space" herein, as indicated by reference numeral 410 of fig. 3.

Specifically, referring to the left side of fig. 3, in the use of the device, the directions of the magnetic field lines generated by the metal electrode tracks of the upper layer and the metal electrode tracks of the middle layer are opposite. For example, fig. 3 shows that the magnetic field lines generated by the upper metal electrode tracks are clockwise while the magnetic field lines generated by the middle metal electrode tracks are counterclockwise. Thus, in the null space 410' therebetween, the magnetic lines of force of the two layers of metal electrode tracks will cancel each other, thereby creating a null space in which no effective magnetic lines of force exist.

In the present invention, the applicant found that by changing the arrangement of the metal electrode tracks, the dead space between two adjacent metal electrode tracks where no effective magnetic line exists can be minimized, thereby enhancing the performance of the multilayer inductor device.

According to a second aspect, as aspect 1, the arrangement of the metal electrode tracks may be: the multilayer metal electrode tracks of the multilayer inductor are closely arranged in the vertical direction so that the overall thickness of the magnetic layer between the metal electrode tracks is 100 μm or less.

Fig. 4A shows a schematic structure of the multilayer metal electrode track of scheme 1. As shown in fig. 4A, a plurality of metal electrode tracks 502 are closely arranged in the vertical direction, and the thickness of the magnetic layer space 510 between the metal electrode tracks is compressed to 100 μm or less. Preferably, the thickness of the magnetic layer space 510 is 50 μm or less, for example, 10 μm to 50 μm.

Fig. 4B shows a partially enlarged view of the metal electrode track structure of scheme 1. As described above, such a closely-arranged metal electrode track structure can be formed by using a method such as printing, etching, and laser. Preferably, the structure shown in fig. 4B can be formed using a multiple printing technique.

Specifically, no metal electrode track is formed in the magnetic layer 501b of the lowermost layer. Then, a metal electrode track, for example 502a, is first formed on the next lower layer by a multi-printing technique, and a magnetic layer 501c is further printed on the metal electrode track, and this operation is repeated until a plurality of layers (for example, 3 or 4 layers) of metal electrode tracks and magnetic layers are formed, in which 502a and 501c are stacked on each other. In addition, the two layers of metal electrode tracks 502a may also be connected by a mesh 503. For the mesh, an aluminum alloy mesh may be used, in which the thickness of the central opening is 0.01 to 0.1mm and the tensile strength is 35 to 50N.

The process of the multiple printing technique is as follows:

first, a slurry for a magnetic layer is prepared. Here, a binder, a dispersant, a defoaming agent, and ceramic powder (ferrite material) were added to the solvent, respectively, and dispersion was performed in a ball mill for 3 to 8 hours to prepare a slurry having a viscosity of 200 to 600 CPS.

The solvent, binder, dispersant, defoamer and the like used for preparing the slurry may use materials commonly used in the art and will not be described herein.

Then, the slurry for forming the magnetic layer and the metal slurry (such as silver paste) are subjected to stacking printing according to the design requirements by adopting a mesh, and the specific process steps are as follows:

(1) The thickness of the magnetic layer or the metal layer printed each time is less than 5 μm, and the magnetic layer or the metal layer printed each time is baked at 50-70 ℃ for 1 hour for drying, so that a multilayer structure with the total thickness of less than 100 μm, namely a multilayer metal electrode or a multilayer magnetic layer, is obtained;

(2) The connection points of the metal electrode tracks use a mesh structure (e.g. 1/2, 1/3, 1/4 mesh) to ensure that the metal electrode tracks between different layers can form a complete coil.

Next, according to a second aspect, as an aspect 2, the arrangement of the metal electrode tracks may be: the multi-layer metal electrode tracks of the multi-layer inductor are arranged with step-like mismatches in a cross-section perpendicular to the plurality of magnetic layers. Specifically, the metal electrode tracks of the upper layer are mismatched to the left or the right in a stepped manner layer by layer relative to the metal electrode tracks of the lower layer.

In this regard, referring first to fig. 1B, on one side (left or right in the figure) of the multilayer inductor, the multilayer metal electrodes in the prior art are aligned with each other in the vertical direction. However, the applicant found that by arranging the multi-layered metal electrode tracks in a stepwise mismatched arrangement, the dead space where no effective magnetic flux lines exist can be minimized even without reducing the thickness of the magnetic layer between the multi-layered metal electrode tracks.

Fig. 4C shows a schematic cross-sectional view of a multilayer inductor structure formed by the mismatch of multilayer metal electrode tracks and the distribution of magnetic field lines therein. As shown in fig. 4C, on the cross section perpendicular to the multi-layer metal electrode tracks, the multi-layer metal electrode tracks are arranged in a step-like layer-by-layer manner with a left offset. Specifically, the metal electrode tracks on the upper layer are mismatched to the left layer by layer in a stepped manner with respect to the metal electrode tracks on the lower layer. However, although FIG. 4C shows a left offset arrangement, the present invention also includes a case where the multi-layered metal electrode tracks are arranged in a stepped right offset arrangement.

As shown in fig. 4C, by mismatching the multi-layered metal electrode tracks, the dead space can be greatly reduced even if the thickness of the magnetic layer is kept thick (for example, 20 μm or more), thereby improving the performance of the device.

According to different designs of devices, the metal electrode tracks of the upper layer are mismatched leftwards or rightwards at different distances relative to the metal electrode tracks of the lower layer.

In a second aspect, the metal electrode includes silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), gold (Au), nickel (Ni), or an alloy thereof or a composite thereof.

The material of the magnetic layer may be a magnetic material, i.e. a ceramic material with magnetic properties, mainly a ferrite material, preferably a nickel zinc copper ferrite material.

As described above, a third aspect of the present invention provides a combination of the first and second aspects, that is, a multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein, in a magnetic core region of a coil pattern formed by the metal electrode tracks, a ceramic-inorganic material composite body is provided, the ceramic-inorganic material composite body comprising two or more first layers and second layers, the first layers comprising a ceramic material having a positive slope of a curve of a change in dielectric constant with temperature, and the second layers comprising a ceramic material having a negative slope of a curve of a change in dielectric constant with temperature, and the first and second layers being laminated on each other in an alternating manner; and the arrangement mode of the metal electrode tracks minimizes the dead space between two adjacent metal electrode tracks without effective magnetic lines.

With respect to the arrangement of the ceramic-inorganic material composite body and the metal track, the characteristics thereof are the same as those of the first aspect and/or the second aspect, and thus detailed description thereof is omitted here.

Examples

Hereinafter, the present invention will be explained in detail with reference to examples. However, the embodiments of the present invention may be modified into various other types, and the scope of the present invention should not be limited to the embodiments described below. The embodiments of the present invention are provided to explain the present invention to those having ordinary skill in the art in a complete sense.

Comparative example 1: multilayer inductor of the prior art

A prior art multilayer inductor having the structure shown in fig. 1B was prepared.

Example 1: the utility model discloses a multilayer inductor (including ceramic-inorganic material complex and closely arranged multilayer metal electrode track)

Raw materials: ultrafine ferrite powder provided by Bao steel;

oily organic matter:

solvent: ethyl acetate and isopropanol

Dispersing agent: polyethylene glycol, duPont

DBP plasticizer, U.S. Ferro

Equipment and instrument:

ball mill: zirconia planet four-pot ball mill

Test casting machine: 3m long tester, manufacturer: fenghua Gao Ke

WK3260 series DC source and inductance testing instrument

Agilent4396 spectrum analyzer

(1) Preparation of magnetic bodies

The magnetic body is prepared by using superfine ferrite powder as a raw material, adopting the oily organic matter as an additive, preparing slurry by a ball milling process and using a test casting machine.

(2) Preparation of metal electrode tracks and ceramic-inorganic material composites

Dissolving titanium dioxide and limestone powder in a solvent of ethyl acetate and terpineol respectively, adding a modifier (such as M1159 material of FERRO company), and ball-milling for 4 hours by using a ball mill to obtain two kinds of slurry: ceramic bodies based on titanium dioxide with a positive temperature coefficient of dielectric constant, and inorganic bodies based on limestone with a negative dielectric constant.

Then, the two slurries are respectively printed on the magnetic core substrate by adopting an alternate printing process, and the composite ceramic body is obtained by high-temperature sintering at about 900 ℃.

The closely packed multilayer electrode structure is obtained as follows:

the binder, the dispersant, the defoamer, and the ceramic powder were added separately and ball milled in a ball mill for 8 hours to prepare a slurry having a viscosity of 400CPS, thereby obtaining a slurry for forming a magnetic layer.

Silver paste was used as a material for forming the electrode tracks.

The method adopts a steel mesh to stack and print the magnetic layer slurry and the silver paste according to design requirements, and comprises the following specific process steps:

for the magnetic layer and the metal track layer, the printing thickness is below 5 mu m each time, 60-degree baking is needed for 1 hour after each printing, and if the layer thickness does not meet the requirement, multiple times of printing and multiple times of baking are carried out.

The connection points of the silver electrodes use a steel mesh structure (such as a 1/2 steel mesh) to ensure that the silver electrodes between different layers can form a complete coil.

(3) Preparation of multilayer inductors

And pressing the magnetic body, the metal electrode track and the ceramic-inorganic material composite body, and sintering at 900 ℃ to obtain the multilayer inductor. The resulting multilayer inductor comprises the ceramic-inorganic material composite described above and closely arranged metal electrode tracks.

(4) Measurement of properties

The electrical properties of the products obtained in comparative example 1 and example 1 were tested using a WK3260 series dc source and inductance tester, and an Agilent4396 spectrum analyzer, the results of which are shown in fig. 5 and 6, respectively.

As can be seen from fig. 5, by providing the ceramic-inorganic material composite body herein, the total dielectric constant of the multilayer inductor is improved with the fluctuation of the gentle AC current, and it is estimated that the improvement is about 15%.

As can be seen from fig. 6, the inductance of the device is improved by the closely-arranged multilayer electrode track structure described herein. In addition, it is estimated that the usable magnetic capacity of the core increases by about 10% and the DC resistance decreases by about 5%.

In addition, referring to fig. 7A and 7B, it can be seen that by the closely-arranged multi-layer electrode track structure described herein, the dead space in which no effective magnetic lines exist in the multi-layer inductor is greatly reduced, thereby improving the device performance.

Example 2: multilayer inductor comprising multilayer metal electrodes in mismatched arrangement

A multilayer inductor including a multilayer metal electrode in a mismatched arrangement according to the present example was produced in a similar manner to example 1, except that the multilayer metal electrode was formed in a mismatched structure as shown in fig. 4C.

The electrical properties of the products obtained in comparative example 1 and example 1 were measured using a WK3260 series dc source and inductance tester and an Agilent4396 spectrum analyzer, and the results are shown in fig. 8, respectively.

Referring to fig. 8, the inductance is improved by the coil layer vertical mismatch structure, and it is estimated that the magnetic flux volume utilization rate has an optimization of about 5% to 10%.

Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims.

Claims (9)

1. A ceramic-inorganic material composite body for a multilayer inductor located at a magnetic core region of a metal electrode track existing in a coil pattern, characterized in that the ceramic-inorganic material composite body comprises two or more first layers and second layers, the first layers comprising a ceramic material having a positive slope of a curve of a change in dielectric constant with temperature, the second layers comprising an inorganic material having a negative slope of a curve of a change in dielectric constant with temperature, and the first layers and the second layers are laminated to each other in an alternating manner.

2. The ceramic-inorganic material composite according to claim 1, wherein the ceramic material having a positive slope of a change in dielectric constant with temperature is selected from titanium dioxide and zirconium dioxide.

3. The ceramic-inorganic material composite of claim 1, wherein the inorganic material having a negative slope of a curve of a change in dielectric constant with temperature is selected from the group consisting of calcium carbonate, calcium bicarbonate and calcium oxide.

4. The ceramic-inorganic material composite of claim 1, wherein the metal electrode comprises silver (Ag), platinum (Pt), palladium (Pd), copper (Cu), gold (Au), or nickel (Ni).

5. A multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein a ceramic-inorganic material composite body is provided in a magnetic core region of a coil pattern formed by the metal electrode tracks, characterized in that the ceramic-inorganic material composite body is as set forth in any one of claims 1 to 4.

6. A multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, wherein the metal electrode tracks are arranged in such a manner that an ineffective space between adjacent two metal electrode tracks where no effective magnetic lines of force exist is minimized, wherein,

the arrangement mode of the metal electrode tracks is as follows: closely arranging the multilayer metal electrode tracks of the multilayer inductor in a vertical direction such that the overall thickness of the magnetic layer between the metal electrode tracks is 100 μm or less; or

The arrangement mode of the metal electrode tracks is as follows: the multi-layer metal electrode tracks of the multi-layer inductor are arranged with step-like mismatches in a cross-section perpendicular to the plurality of magnetic layers.

7. The multilayer inductor of claim 6, wherein metal electrode tracks of an upper layer are staggered left or right step-by-step relative to metal electrode tracks of a lower layer in the case that the metal electrode tracks of the multilayer inductor are arranged with step-wise mismatches.

8. A multilayer inductor comprising a plurality of magnetic layers and metal electrode tracks formed on the magnetic layers, characterized in that in a core region of a coil pattern formed by the metal electrode tracks, a ceramic-inorganic material composite is provided, the ceramic-inorganic material composite comprising two or more first layers and second layers, the first layers comprising a ceramic material having a positive slope of a curve of a change in dielectric constant with temperature, the second layers comprising an inorganic material having a negative slope of a curve of a change in dielectric constant with temperature, and the first layers and the second layers being laminated on each other in an alternating manner; and the arrangement mode of the metal electrode tracks minimizes the invalid space between two adjacent metal electrode tracks without effective magnetic lines, wherein,

the arrangement mode of the metal electrode tracks is as follows: closely arranging the multilayer metal electrode tracks of the multilayer inductor in a vertical direction such that the overall thickness of the magnetic layer between the metal electrode tracks is 100 μm or less; or

The arrangement mode of the metal electrode tracks is as follows: in a cross section perpendicular to the plurality of magnetic layers, the multi-layer metal electrode tracks of the multi-layer inductor are arranged with step-like mismatches.

9. The multilayer inductor as claimed in claim 8, wherein the ceramic material having a positive slope of a change in dielectric constant with temperature is selected from titanium dioxide or zirconium dioxide, and the ceramic material having a negative slope of a change in dielectric constant with temperature is selected from calcium carbonate, calcium bicarbonate and calcium oxide.

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