CN105846789B

CN105846789B - Low-pass filter and preparation method thereof

Info

Publication number: CN105846789B
Application number: CN201610169478.6A
Authority: CN
Inventors: 罗洪梁; 林亚梅; 黄寒寒; 朱建华; 刘季超; 胡志明
Original assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd; China Zhenhua Group Science and Technology Co Ltd
Current assignee: Shenzhen Zhenhua Ferrite and Ceramic Electronics Co Ltd; China Zhenhua Group Science and Technology Co Ltd
Priority date: 2016-03-23
Filing date: 2016-03-23
Publication date: 2018-07-24
Anticipated expiration: 2036-03-23
Also published as: CN105846789A

Abstract

The present invention relates to a kind of low-pass filters and preparation method thereof.The ceramic body of low-pass filter includes bottom plate and stacks gradually in the first capacitor layers, multiple inductor layers and multiple second capacitor layers on bottom plate, at least first capacitance is collectively formed in the second electrode pattern of first capacitor layers and the first electrode pattern of bottom plate, and each first capacitance is that first electrode pattern is collectively formed with second electrode pattern；The multiple electrodes of multiple inductor layers are electrically connected to form multiple concatenated inductance, and an electrode of multiple inductor layers connects to form an inductance, and each first capacitance is connected with an inductance；At least second capacitance is collectively formed in the third electrode pattern of multiple second capacitor layers, and the third electrode pattern that each second capacitance is multiple second capacitor layers is collectively formed, each second capacitance and an inductance in parallel.Above-mentioned low-pass filter 3dB cutoff frequencies are higher, operating frequency range is wider, Out-of-band rejection is higher, microwave frequency band preferably and is easy to minimize using consistency.

Description

Low-pass filter and preparation method thereof

Technical field

The present invention relates to filter fields more particularly to a kind of low-pass filter and preparation method thereof.

Background technology

Filter is a kind of two-port network with selecting frequency characteristic, in the filtering clutter signal of the communications industry always All play indispensable role.LTCC (Low Temperature Co-fired Ceramic, LTCC) filter is one Kind Novel Filter, it is via Tape-casting Technology for Ceramic Materials technique, high accuracy prints technology, laminates forming technique and low temperature What the multiple technologies such as sintering technology were prepared, since it has small, filter with low insertion loss passband and Wide stop bands and high inhibition etc. special Property, the systems such as satellite communication, radar navigation, automotive electronics are widely used in, and be widely used in VHF/UHF transmittings It is indispensable important devices in microwave system in the function modules such as device/receiver, harmonic shutter, digital-to-analogue converter, The quality of performance often directly affects the performance indicator of entire communication system.However, with the development of communication technologies, a new generation moves The appearance of dynamic mechanics of communication and the demand of new-type weapon and equipment so that people are wide to operating frequency range, 3dB cutoff frequencies High, Out-of-band rejection height, microwave frequency band are more and more obvious using the demand for the low-pass filter that consistency is preferable and minimizes.Cause This, be badly in need of studying a kind of operating frequency range is wide, 3dB cutoff frequencies are high, Out-of-band rejection is high, microwave frequency band using consistency compared with Low-pass filter that is good and can minimizing.

Invention content

In consideration of it, that it is necessary to provide a kind of 3dB cutoff frequencies is higher, operating frequency range is wider, Out-of-band rejection is higher, Microwave frequency band preferably and is easy to the low-pass filter minimized using consistency.

In addition, also providing a kind of preparation method of low-pass filter.

A kind of low-pass filter, including ceramic body, the ceramic body include bottom plate and stack gradually on the bottom plate First capacitor layers, multiple inductor layers and multiple second capacitor layers, wherein：

The bottom plate includes first medium layer and the first electrode pattern that is formed on the first medium layer；

First capacitor layers are laminated on the first medium layer, and first capacitor layers include second dielectric layer and shape Second electrode pattern in second dielectric layer described in Cheng Yu, the second electrode pattern are collectively formed with the first electrode pattern At least one first capacitance, and each first capacitance is the first electrode pattern and the common shape of the second electrode pattern At；

Multiple inductor layers are stacked gradually in the second dielectric layer, and each inductor layer includes third dielectric layer And it is formed in the electrode at multiple intervals on the third dielectric layer, multiple electrodes of multiple inductor layers are electrically connected shape It connects to form an inductance at an electrode of multiple concatenated inductance, and multiple inductor layers, wherein each First capacitance is connected with an inductance；

Multiple second capacitor layers are stacked gradually in the third dielectric layer farthest from first capacitor layers On, each second capacitor layers include the 4th dielectric layer and the third electrode pattern that is formed on the 4th dielectric layer, more At least second capacitance, and each second capacitance is collectively formed in the third electrode pattern of a second capacitor layers The third electrode pattern for multiple second capacitor layers is collectively formed, each second capacitance and an inductance It is in parallel.

Each inductor layer further includes multiple being arranged in the first of the third dielectric layer in one of the embodiments, Electric binding post, first electric binding post are sequentially connected in series an electrode of multiple inductor layers to form an electricity Sense, an electrode of two inductor layers of furthest apart is electrically connected so that two neighboring by first electric binding post The inductance series connection, and first electric binding post connects each first capacitance with an inductance；It is each described Second capacitor layers further include multiple the second electric binding posts for being arranged in the 4th dielectric layer, and second electric binding post will be multiple The third electrode pattern of second capacitor layers is electrically connected so that each second capacitance and an institute with the inductance State inductance in parallel.

In one of the embodiments, first capacitor layers be it is multiple, multiple first capacitor layers stack gradually in On the first medium layer, the first electrode pattern of the second electrode pattern and the bottom plate of multiple first capacitor layers At least first capacitance is collectively formed, each first capacitance is second electricity of multiple first capacitor layers Pole figure case is collectively formed with the first electrode pattern, wherein multiple inductor layers are stacked gradually in farthest from the bottom plate First capacitor layers the second dielectric layer on.

In one of the embodiments, the 4th dielectric layer, the third dielectric layer, the second dielectric layer with it is described The material of first medium layer is identical ceramic material.

In one of the embodiments, the 4th dielectric layer, the third dielectric layer, the second dielectric layer with it is described The tangent value of the dielectric loss angle of first medium layer is respectively less than or is equal to 6 × 10^-4。

In one of the embodiments, the 4th dielectric layer, the third dielectric layer, the second dielectric layer with it is described The dielectric constant of first medium layer is 3~96.

A kind of preparation method of low-pass filter, includes the following steps：

First medium green body layer is provided, forms first electrode pattern on a surface of the first medium green body layer, Obtain bottom plate green body；

Second medium green body layer is provided, in the one side that the first medium green body layer is formed with the first electrode pattern The second medium green body layer is laminated, and second electrode pattern is formed in the second medium green body layer, and makes described second Electrode pattern and the first electrode pattern are collectively formed at least first capacitance, and each first capacitance is described the One electrode pattern and the second electrode pattern of the first capacitance green body layer are collectively formed, and obtain the first capacitance green body layer；

Multiple third medium green body layers are provided, the one of the second electrode pattern is formed in the second medium green body layer On face, according to one layer of third medium green body layer of stacking, then multiple interval settings are formed in the third medium green body layer Electrode sequence repetitive operation, to form the inductance green body layer of multiple stackings, and make the multiple of multiple inductance green body layers The electrode is electrically connected to form multiple concatenated inductance, and an electrode of multiple inductance green body layers connects to form one The inductance, and each first capacitance is made to connect with an inductance；

Multiple 4th medium green body layers are provided, in the third medium base farthest from the first capacitance green body layer Body layer is formed in the one side of the electrode, according to one layer of the 4th medium green body layer of stacking, then in the 4th medium base The sequence repetitive operation that third electrode pattern is formed on body layer to form the second capacitance green body layer of multiple stackings, and makes multiple At least second capacitance is collectively formed in the third electrode pattern of second capacitor layers, and each second capacitance is more The third electrode pattern of a second capacitance green body layer is collectively formed, and makes described in each second capacitance and one Inductance in parallel obtains laminated construction；

The laminated construction is laminated, laminate is obtained；

The laminate is sintered, ceramic body is obtained；And

External electrode is formed on the ceramic body, obtains low-pass filter.

It is offered in the third medium green body layer and the 4th medium green body layer in one of the embodiments, more A electrical connection hole；Wherein, while forming the step of multiple spaced electrodes in the third medium green body layer, The first conductive material is filled in the electrical connection hole of the third medium green body layer, and makes to be filled in the third medium base First conductive material in the electrical connection hole of body layer by an electrode of multiple inductance green body layers successively Series connection forms an inductance, and an electrode of two of the furthest apart inductance green body layers is electrically connected so that Two neighboring inductance series connection, and make to be filled in described first leading in the electrical connection hole of the third medium green body layer Electric material connects each first capacitance with an inductance；The third is formed in the 4th medium green body layer While the step of electrode pattern, the second conductive material is filled in the electrical connection hole of the 4th medium green body layer, with Make second conductive material being filled in the electrical connection hole of the 4th medium green body by the third electrode pattern It is electrically connected so that each second capacitance and an inductance in parallel with the inductance.

The step of obtaining the first capacitance green body layer in one of the embodiments, be specially：There is provided multiple described Second medium green body layer, in the one side that the first medium green body layer is formed with the first electrode pattern, according to one layer of stacking The second medium green body layer, then form in the second medium green body layer sequence of the second electrode pattern and repeat to grasp Make, to form multiple stack gradually in first in the one side that the first medium green body layer is formed with the first electrode pattern Capacitance green body layer, and keep the second electrode pattern of multiple first capacitance green body layers and the first electrode pattern common At least one first capacitance is formed, and the second electrode that each first capacitance is multiple first capacitor layers Pattern is collectively formed with the first electrode pattern；Wherein, in the second medium farthest from the bottom plate green body layer Green body layer is formed in the one side of the second electrode pattern, according to one layer of third medium green body layer of stacking, then described The sequence repetitive operation of multiple spaced electrodes is formed in third medium green body layer.

The step of laminated construction is laminated in one of the embodiments, be specially：It will using the method for isostatic pressed Laminated construction pressurize 3~35 minutes under conditions of 45~93 DEG C, 18~45MPa.

The ceramic body of above-mentioned low-pass filter includes bottom plate and stacks gradually in the first capacitor layers on bottom plate, multiple inductance Layer and multiple second capacitor layers, and multiple inductor layers form multiple concatenated inductance, the first electrode pattern of bottom plate and the first electricity The second electrode pattern of appearance layer is collectively formed to be collectively formed with inductance simultaneously with concatenated first capacitance of inductance, multiple second capacitor layers The second capacitance and inductance of connection, to introduce " resonance zero " to effectively improve the Out-of-band rejection of low-pass filter；On and The multiple electrodes for stating multiple inductor layers of low-pass filter are electrically connected to form multiple concatenated inductance, and one of multiple inductor layers Electrode connects to form an electrode, and at least first capacitance is collectively formed with second electrode pattern in first electrode pattern, each First capacitance is that first electrode pattern and a second electrode pattern of the first capacitor layers are collectively formed, multiple second capacitor layers At least second capacitance is collectively formed in third electrode pattern, and each second capacitance is that the electrode pattern of multiple second capacitor layers is total With formation, and each first capacitance is connected with an inductance, each second capacitance and an inductance in parallel, " mostly electric to be formed The multistage cascade structure form of appearance+more inductance+series parallel resonances ", to make full use of the parasitic capacitance of inductance and the parasitism of capacitance " ghost effect " under microwave frequency minimizes the influence of microwave device electric performance stablity, is conducive to improve low pass by inductance 3dB cutoff frequencies, operating frequency range and the use under microwave frequency band of filter so that above-mentioned low-pass filter have compared with High 3dB cutoff frequencies, wider working range and microwave frequency band is good using consistency, and 3dB cutoff frequencies reach as high as 15000MHz；Meanwhile the multiple electrodes of multiple inductor layers of above-mentioned low-pass filter are electrically connected to form multiple concatenated inductance, and Each inductance connects to be formed for an electrode of multiple inductor layers, so that the electrical interconnection of inductance is three-dimensional spiral structure, and Under identical effective inductance value, the inductance cabling of above-mentioned three-dimensional spiral structure is laid out the inductance cabling cloth than planar spiral structures Office has higher self-resonant frequency and quality factor, is conducive to the miniaturization of low-pass filter.

Description of the drawings

Fig. 1 is the structural schematic diagram of the low-pass filter of an embodiment；

Fig. 2 is the exploded view that cover board and external electrode is omitted in low-pass filter shown in FIG. 1；

Fig. 3 is the structural schematic diagram of three inductor layers of low-pass filter shown in Fig. 2；

Fig. 4 is a kind of circuit connection diagram of low-pass filter shown in FIG. 1；

Fig. 5 is another circuit connection diagram of low-pass filter shown in FIG. 1；

Fig. 6 is the preparation flow figure of the low-pass filter of an embodiment；

Fig. 7 is the insertion loss curve graph of the low-pass filter of embodiment 1；

Fig. 8 is the insertion loss curve graph of the low-pass filter of embodiment 2；

Fig. 9 is the insertion loss curve graph of the low-pass filter of embodiment 3；

Figure 10 is the insertion loss curve graph of the low-pass filter of embodiment 4；

Figure 11 is the insertion loss curve graph of the low-pass filter of embodiment 5；

Figure 12 is the insertion loss curve graph of the low-pass filter of embodiment 6；

Figure 13 is the insertion loss curve graph of the low-pass filter of comparative example 1.

Specific implementation mode

To facilitate the understanding of the present invention, below with reference to relevant drawings to invention is more fully described.In attached drawing Give the preferred embodiment of the present invention.But the present invention can realize in many different forms, however it is not limited to herein Described embodiment.Keep the understanding to the disclosure more saturating on the contrary, purpose of providing these embodiments is It is thorough comprehensive.

Unless otherwise defined, all of technologies and scientific terms used here by the article and belong to the technical field of the present invention The normally understood meaning of technical staff is identical.Used term is intended merely to description tool in the description of the invention herein The purpose of the embodiment of body, it is not intended that in the limitation present invention.

As shown in Figure 1, the low-pass filter 10 of an embodiment includes ceramic body 100 and is formed on ceramic body 100 External electrode 200.

Also referring to Fig. 2, the substantially cuboid-type of ceramic body 100.Wherein, ceramic body 100 includes bottom plate 110, first Capacitor layers 120, multiple inductor layers 130, multiple second capacitor layers 140 and cover board (not shown).

Bottom plate 110 includes first medium layer 112 and the first electrode pattern 114 being formed on first medium layer 112.Specifically , first electrode pattern 114 is formed on a surface of first medium layer 112.

Wherein, the material of first medium layer 112 is ceramic material, and the dielectric loss tangent of an angle of first medium layer 112 Value is less than or equal to 6 × 10^-4.And the dielectric constant of ceramic material is 3~96.

Preferably, the material of first medium layer 112 is alumina-based ceramic.For example, first medium layer 112 can mainly be used such as Lower ceramic powder is prepared：The model LFA and dielectric constant of Shenzhen Zhenhuafu Electronics Co., Ltd.'s production be respectively 4.0, The ceramic powder that 7.1 and 13.6 ceramic powder or model LFD and dielectric constant is 18.3.

Wherein, the dielectric constant of first medium layer 112 can according to the 3dB cutoff frequencies of prepared low-pass filter 10 into Row selection selects dielectric constant for 18~53 for example, when the 3dB cutoff frequencies of required low-pass filter 10 are less than 350MHz Ceramic material；When the 3dB cutoff frequencies of required low-pass filter 10 are 350~990MHz, select dielectric constant for 9~18 Ceramic material；When the 3dB cutoff frequencies of required low-pass filter 10 are 990~2800MHz, select dielectric constant for 5~9 Ceramic material；When the 3dB cutoff frequencies of required low-pass filter 10 are 2800MHz or more, select dielectric constant for 5 or less Ceramic material.

The material of first electrode pattern 114 is silver electrode pattern.

First capacitor layers 120 are laminated on first medium layer 112.Specifically, the first capacitor layers 120 are laminated in first medium Layer 112 is formed in the one side of first electrode pattern 114.Wherein, the first capacitor layers 120 include second dielectric layer 122 and are formed In the second electrode pattern 124 in second dielectric layer 122.Wherein, second electrode pattern 124 and first electrode pattern 114 are common At least one first capacitance is formed, each first capacitance is the second electrode pattern 124 of first electrode pattern 114 and the first capacitance It is collectively formed.

Wherein, the first capacitor layers 120 can be one, or multiple.When the first capacitor layers 120 are one, the At least second capacitance is collectively formed with first electrode pattern 114 in second electrode pattern 124 in one capacitor layers 120, at this point, Each second capacitance is that first electrode pattern 114 is collectively formed with second electrode pattern 124；When the first capacitor layers 120 are multiple When, multiple first capacitor layers 120 are stacked gradually on first medium layer 112, the second electrode pattern of multiple first capacitor layers 120 124 are collectively formed at least first capacitance with first electrode pattern 114, and each first capacitance is multiple first capacitor layers 120 second electrode pattern 124 is collectively formed with first electrode pattern 114.

For example, in embodiment shown in Fig. 2, the first capacitor layers 120 are two, and two the first capacitor layers 120 stack gradually In in the one side that first medium layer 112 is formed with first electrode pattern 114.Second of the first capacitor layers 120 far from bottom plate 110 Electrode pattern 124 is identical as the shape of first electrode pattern 114 of bottom plate 110, and position is corresponding.Close to the of bottom plate 110 The second electrode pattern 124 of one capacitor layers 120 is made of three spaced electrodes, and the position of three electrodes is with The position of one electrode pattern 114 is corresponding, to form three the first capacitances.I.e. each first capacitance is first electrode pattern 114, an electrode of the second electrode pattern 124 of first capacitor layers 120 close to bottom plate 110 and far from bottom plate 110 The second electrode pattern 124 of first capacitor layers 120 is collectively formed.

Wherein, the material identical of the material of second dielectric layer 122 and first medium layer 112.

Wherein, the thickness of first medium layer 112 is more than the thickness of second dielectric layer 122.For example, first medium layer 112 The thickness of substantially 240 microns of thickness, second dielectric layer 122 is 35 microns.

Specifically, second electrode pattern 124 is formed in one side of the second dielectric layer 122 far from bottom plate 110.Wherein, Two electrode patterns 124 are silver electrode pattern.

Multiple inductor layers 130 are stacked gradually in second dielectric layer 122.Specifically, multiple inductor layers 130 stack gradually in Second dielectric layer 122 is formed on the side of second electrode pattern 124.Specifically, when the first capacitor layers 120 are multiple, it is multiple Inductor layer 130 is stacked gradually in the second dielectric layer 122 of first capacitor layers 120 farthest from bottom plate 110.Wherein, often A inductor layer 130 includes third dielectric layer 132 and multiple spaced 132 electrodes being formed on third dielectric layer 132.It is more The multiple electrodes 132 of a inductor layer 130 are electrically connected to form multiple concatenated inductance, and an electrode array of multiple inductor layers 130 Connection forms an inductance, wherein each first capacitance is connected with an inductance.

Wherein, the material identical of the material of third dielectric layer 132 and first medium layer 112.

Preferably, it is more than it near the thickness of the third dielectric layer 132 of an inductor layer 130 of the first capacitor layers 120 The thickness of the third dielectric layer 132 of remaining inductor layer 130, to reduce the coupling and interference between inductance and the first capacitance.And The thickness of the third dielectric layer 132 of remaining inductor layer 130 is equal.For example, near an inductance of the first capacitor layers 120 The thickness of the third dielectric layer 132 of layer 130 is about 220 microns, and the thickness of remaining third dielectric layer 132 is 35 microns. It is appreciated that in other embodiments, the thickness of the third dielectric layer 132 of multiple inductor layers 130 can also be equal.

Specifically, electrode 132 is formed on surface of the third dielectric layer 132 far from the first capacitor layers 120.Wherein, electrode 132 be silver electrode.

Wherein, the multiple electrodes 132 of multiple inductor layers 130 are electrically connected to form multiple concatenated inductance, and multiple inductor layers 130 electrode 132 series connection forms an inductance, and it is in three-dimensional spiral structure that the cabling of inductance can be made, which to be laid out, so that in phase Under same effective inductance value, the inductance cabling layout of above-mentioned three-dimensional spiral structure is laid out tool than the inductance cabling of planar spiral structures There are higher self-resonant frequency and quality factor, is conducive to the miniaturization of low-pass filter 10.

Specifically, each inductor layer 130 further includes multiple the first electric binding posts for being arranged in third dielectric layer 132, first Electric binding post is sequentially connected in series an electrode 132 of multiple inductor layers 130 to form an inductance, and the first electric binding post will be separated by most One electrode 132 of two remote inductor layers 130 is electrically connected so that two neighboring inductance series connection.That is the one of multiple inductor layers 130 A electrode 132 is sequentially connected electrically to form an inductance；Near the first capacitor layers 120 an inductor layer 130 electrode and The electrode 132 of an inductor layer 130 farthest from the first capacitor layers 120 is electrically connected to realize the series connection between two inductance, from And it is in three-dimensional spiral structure that so that the cabling of inductance is laid out.

For example, as shown in Fig. 2, specifically in the illustrated embodiment, inductor layer 130 is three, first inductor layer 130 (near an inductor layer 130 of bottom plate 110) and second inductor layer 130 all have four electrodes, third inductor layer 130 There are three electrode 132, an electrodes 132 and third of 132, second inductor layers 130 of an electrode of first inductor layer 130 One electrode 132 of a inductor layer 130 is sequentially connected in series to form an inductance.I.e. in figure 3, A1 and A2, E1 and E2 and H1 and H2 indicates the both ends of three electrodes 132 of a uppermost inductor layer 130 respectively, B1 and B2, F1 and F2, I1 and I2 and K1 and K2 indicates the both ends of four electrodes 132 of intermediate inductor layer 130, D1 and D2, G1 and G2 and J1 and J2 difference respectively Indicate the both ends of wherein three electrodes 132 of a undermost inductor layer 130, wherein A2 and B1 electrical connections, B2 are electrically connected with D1 It connects, forms an inductance；E2 and F1 electrical connections, F2 are electrically connected with G1, form an inductance；H2 is electrically connected with I1, I2 and J1 electricity Connection forms an inductance；Wherein, D2 is electrically connected with E1, and two adjacent inductance are connected in G2 and H1 electrical connections.

Specifically, the first electric binding post connects each first capacitance with an inductance.I.e. when the first capacitor layers 120 are one When a, the electrode 132 of second electrode pattern 124 and inductor layer 130 is electrically connected so that each first capacitance by the first electric binding post It connects with an inductance；When the first capacitor layers 120 are multiple, columnar be electrically connected also is equipped in each second dielectric layer 122 Fitting, at this point, electrical connector is electrically connected with the first electric binding post and each first capacitance will be made to connect with an inductance.

Specifically, the material of the first electric binding post and electrical connector is silver.

Multiple second capacitor layers 140 are stacked gradually to be situated between in the third from a 120 farthest inductor layer 130 of the first capacitor layers On matter layer 132.Specifically, multiple second capacitor layers 140 are stacked gradually in from a 120 farthest third medium of the first capacitor layers Layer 132 is formed in the one side of electrode.Wherein, each second capacitor layers 140 including the 4th dielectric layer 142 and are formed in the 4th Jie Third electrode pattern 144 on matter layer 142.Wherein, the third electrode pattern 144 of multiple second capacitor layers 140 together forms at Few second capacitance, and the third electrode pattern 144 that each second capacitance is multiple second capacitor layers 140 is collectively formed.Its In, each second capacitance and an inductance in parallel.And multiple second capacitances are in parallel.

For example, in embodiment shown in Fig. 2, the second capacitor layers 140 are three, and the third of each second capacitor layers 140 Electrode pattern 144 is formed by three spaced electrodes, and each second capacitance is that an electrode of three the second capacitances is total With formation.I.e. each second capacitance by an electrode of the second capacitor layers 140 near inductor layer 130, positioned at intermediate the One electrode of two capacitor layers 140 and an electrode of second capacitor layers 140 farthest from inductor layer 130 are collectively formed.

Wherein, first capacitance, an inductance and second capacitance form a resonant tank.For example, Fig. 4 is one The circuit connection diagram of the low-pass filter 10 of a embodiment, wherein the first capacitance is three, and the second capacitance is two, and inductance is Three, three the first capacitances are indicated with C1, C3 and C5 respectively, and two the second capacitor layers 140 are indicated with C2 and C4 respectively, three electricity Feel layer 130 and distinguish L1, L2 and L3 and indicate, L1, L2 and L3 series connection, C1 connect with L1, and C3 and L2 series connection, C5 and L3 connect, C2 with L1 is in parallel, and C4 and L2 are in parallel.Wherein, C2 and C4 be parallel resonance capacitance, L1, C1 and C2 formed a resonant tank, L2, C3 and C4 forms a resonant tank.It is appreciated that the quantity of the second capacitance is not limited to the quantity less than the first capacitance, in other implementations In example, the quantity of the second capacitance can also be equal to the quantity of the first capacitance, for example, in another embodiment, as shown in figure 5, Difference lies in have 3 the second capacitances and 4 to circuit connection diagram shown in the circuit connection diagram and Fig. 4 of the embodiment in Fig. 5 Inductance, another second capacitance indicate that another inductance is indicated with L4 with C6, at this point, C6 is in parallel with L3, L3, C5 and C6 are formed One resonant tank, at this point, lead is drawn from L4.

Specifically, each second capacitor layers 140 further include multiple the second electric binding posts for being arranged in the 4th dielectric layer 142, Second electric binding post is by each second capacitance and an inductance in parallel.Wherein, the material of the second electric binding post is silver.

Specifically, the material identical of the material and first medium layer 112 of the 4th dielectric layer 142.Preferably, near inductance The thickness of 4th dielectric layer 142 of one the second capacitor layers 140 of layer 130 is more than the 4th Jie of remaining the second capacitor layers 140 The thickness of matter layer 142, to reduce the coupling and interference between inductance and the second capacitance.The thickness of remaining the 4th dielectric layer 142 Degree is equal.For example, the thickness near the 4th dielectric layer 142 of the second capacitor layers 140 of inductor layer 130 is 220 microns, 142 thickness of the 4th dielectric layer of the second remaining capacitor layers 140 is 45 microns.

Third electrode pattern 144 is silver electrode pattern.Specifically, first electrode pattern 114, second electrode pattern 124, every The electrode of a inductor layer 130 and the thickness of third electrode pattern 144 are equal.

Wherein, the quantity of the first capacitance is less than or equal to the quantity of inductance, and the quantity of the quantity of the first capacitance and inductance Be not much different in 1, second capacitance quantity be less than inductance quantity, the function of low-pass filter 10 is better achieved.

Cover board is laminated in the one side that fourth dielectric layer 142 farthest from inductor layer 130 is formed with third electrode pattern 144 On.And cover board covers the third electrode pattern 144 on the 4th dielectric layer 142 farthest from inductor layer 130.Wherein, the material of cover board The material identical of material and first medium layer 112.

External electrode 200 is four.Two of which external electrode 200 is located at the both ends of ceramic body 100, and wraps up ceramic body 100 both ends.Two external electrodes 200 are also referred to as termination electrode.Two termination electrodes are respectively the input terminal of low-pass filter 10 The anode of anode and output end.Wherein, two inductance positioned at both ends of concatenated multiple inductance respectively with two termination electrode electricity Connection.

Wherein, each termination electrode includes the silver layer being laminated on ceramic body 100.In order to meet the welding of low-pass filter 10 It is required that termination electrode further includes stacking gradually in nickel layer and tin layers on silver layer.Nickel layer is for heat-insulated, and tin layers are convenient for welding.And Nickel layer and tin layers are set on silver layer.

Other two external electrode 200 is located at the middle part of ceramic body 100, and is relatively arranged on the both sides of ceramic body 100.It should Two external electrodes 200 are also referred to as central electrode.The two central electrodes are the common ground end of low-pass filter 10, and this two Central electrode is electrically connected with capacitance.Wherein, two central electrodes are silver electrode.

Above-mentioned low-pass filter 10 at least has the advantage that：

(1) ceramic body 100 of above-mentioned low-pass filter 10 includes bottom plate 110 and stacks gradually in first on bottom plate 110 Capacitor layers 120, multiple inductor layers 130 and multiple second capacitor layers 140, and multiple inductor layers 130 form multiple concatenated inductance, The second electrode pattern 124 of the first electrode pattern 114 of bottom plate 110 and the first capacitor layers 120 is collectively formed concatenated with inductance The inductance in parallel with the second capacitance is collectively formed in first capacitance, multiple second capacitor layers 140, to introduce " resonance zero " to have Effect ground improves the Out-of-band rejection of low-pass filter 10；And the multiple electrodes of multiple inductor layers 130 of above-mentioned low-pass filter 10 132 are electrically connected to form multiple concatenated inductance, and an electrode 132 of multiple inductor layers 130 connects and forms an electrode, and first At least first capacitance is collectively formed with second electrode pattern 124 in electrode pattern 114, and each first capacitance is first electrode figure Case 114 and a second electrode pattern 124 of the first capacitor layers 120 are collectively formed, the third electrode of multiple second capacitor layers 140 At least second capacitance is collectively formed in pattern 144, and each second capacitance is that the electrode pattern of multiple second capacitor layers 140 is common Formed, and each first capacitance is connected with an inductance, each second capacitance and an inductance in parallel, to formed " more capacitances+ The multistage cascade structure form of more inductance+series parallel resonances ", to make full use of the parasitic capacitance of inductance and the parasitism electricity of capacitance " ghost effect " under microwave frequency minimizes the influence of microwave device electric performance stablity, is conducive to improve low pass filtered by sense 3dB cutoff frequencies, operating frequency range and the use under microwave frequency band of wave device 10 so that above-mentioned low-pass filter 10 has Higher 3dB cutoff frequencies, wider working range and microwave frequency band are good using consistency, and 3dB cutoff frequencies reach as high as 15000MHz；Meanwhile the multiple electrodes 132 of multiple inductor layers 130 of above-mentioned low-pass filter 10 are electrically connected to form multiple series connection Inductance, and an electrode 132 series connection that each inductance is multiple inductor layers 130 is formed, so that the electrical interconnection of inductance is Three-dimensional spiral structure, and under identical effective inductance value, the inductance cabling layout of above-mentioned three-dimensional spiral structure compares snail The inductance cabling layout of structure has higher self-resonant frequency and quality factor, is conducive to the miniaturization of low-pass filter 10.

(2) the 4th dielectric layer 142 of above-mentioned low-pass filter 10, third dielectric layer 132, second dielectric layer 122 and first The material of dielectric layer 112 is identical ceramic material, and the tangent value of the dielectric loss angle of ceramic material be less than or equal to 6 × 10^-4, i.e. capacitance and inductance separated using the material of identical high-frequency low-consumption, is conducive to the coupling between small electric sense and capacitance And interference, and the problem that reliability is relatively low caused by dissimilar materials mismatches is completely avoided, to substantially increase low pass 10 reliability of filter so that above-mentioned low-pass filter 10 has higher reliability.

(3) there are two central electrodes for the tool of above-mentioned low-pass filter 10, and the public affairs that two central electrodes are low-pass filter 10 Ground terminal altogether can shield the interference of extraneous signal, ensure the stability of 10 electrical property of low-pass filter.

As shown in fig. 6, the preparation method of the low-pass filter of an embodiment, prepares for a kind of of above-mentioned low-pass filter The preparation method of method, the low-pass filter includes the following steps：

Step S310：First medium green body layer is provided, first electrode is formed on a surface of first medium green body layer Pattern obtains bottom plate green body.

Wherein, first medium green body layer is prepared by ceramic slurry, and ceramic slurry includes ceramic powder, and ceramic powder The tangent value of sintered dielectric loss angle is less than or equal to 6 × 10^-4, and the dielectric constant of ceramic powder is 3~96.Wherein, The particle surface of ceramic powder is positively charged.Preferably, ceramic powder is alumina-based ceramic powder, for example, Shenzhen Zhenhua is rich The model LFA and dielectric constant of Electronics Co., Ltd.'s production are respectively 4.0,7.1 and 13.6 ceramic powder or model The ceramic powder for being 18.3 for LFD and dielectric constant.

Specifically, ceramic slurry further includes solvent, plasticizer, binder and dispersant.Wherein, according to mass percent, Ceramic slurry include 35~60% ceramic powder, 34.4~55% solvent, 1.0~4.0% plasticizer, 4.41~ 8.5% binder and 0.09~0.9% dispersant.The ceramic slurry that the proportioning makes is uniformly dispersed, stability is good, nothing Sedimentation and do not reunite, to ensure its in molding, printing and lamination process bubble-free, easy demoulding, easily bond and with suitable Ductility.

Wherein, solvent can be the mixture of ethyl alcohol and ethyl acetate, wherein the mass ratio of ethyl alcohol and ethyl acetate is 3: 7.Plasticizer can be polyethylene glycol.Binder can be polyvinyl butyral.Dispersant can be oleic acid.

The preparation process of above-mentioned ceramic slurry is specific as follows：By ceramic powder, solvent, plasticizer and dispersant ball milling 10~20 hours, binder is then added, continues ball milling 15~35 hours, ball milling frequency is 50~190Hz, obtains ceramic slurry Material.

Wherein, the method that tape casting can be used in first medium green body layer is prepared.It is configured to make pottery according to said components After porcelain slurry, ceramic slurry is stood into 30~90 minutes or froth in vacuum, then tape casting, in order to eliminate in ceramic slurry Bubble.

First electrode pattern is to be formed in first medium green body layer using silver paste silk-screen printing.The thickness of first electrode pattern Degree is 5 microns~12 microns.

Step S320：Second medium green body layer is provided, the one side of first electrode pattern is formed in first medium green body layer Upper stacking second medium green body layer, and second electrode pattern is formed in second medium green body layer, and make second electrode pattern with At least first capacitance is collectively formed in first electrode pattern, and each first capacitance is first electrode pattern and second electrode figure Case is collectively formed, and obtains the first capacitance green body layer.

Wherein, the thickness of first medium green body is more than the thickness of second medium green body.For example, the thickness of first medium green body layer Degree is 240 microns, and the thickness of second medium green body layer is 43 microns.

Wherein, the preparation method of second medium green body is identical as first medium green body.And second medium green body layer uses Ceramic slurry is identical as the ceramic slurry of first medium green body layer.

Wherein it is possible to prepare a first capacitance green body layer, multiple first capacitance green body layers can also be prepared.When the first electricity When to hold green body layer be multiple, the step of obtaining the first capacitance green body layer, is specially：Multiple second medium green body layers are provided, first Medium green body layer is formed in the one side of first electrode pattern, according to one layer of second medium green body layer of stacking, then in second medium The sequence repetitive operation that second electrode pattern is formed in green body layer, is formed with forming multiple stack gradually in first medium green body layer There is the first capacitance green body layer in the one side of first electrode pattern, at this point, the second electrode pattern of multiple first capacitance green body layers It is collectively formed at least first capacitance with first electrode pattern, and one that each first capacitance is multiple first capacitor layers the Two electrode patterns are collectively formed with first electrode pattern.

Step S330：Multiple third medium green body layers are provided, second electrode pattern is formed in second medium green body layer On on one side, according to one layer of third medium green body layer of stacking, then multiple spaced electrodes are formed in third medium green body layer Sequence repetitive operation, to form the inductance green body layer of multiple stackings, and the multiple electrodes of multiple inductance green body layers is made to be electrically connected Multiple concatenated inductance are formed, an electrode of multiple inductance green body layers connects to form an inductance, and makes each first capacitance It connects with an inductance.

Wherein, when it is multiple to prepare the first capacitance green body layer in step S320, at one farthest from bottom plate green body layer Second medium green body layer is formed in the one side of second electrode pattern, according to one layer of third medium green body layer of stacking, then in third The sequence repetitive operation of multiple spaced electrodes is formed in medium green body layer.

Wherein, the preparation method of third medium green body layer is identical as the preparation method of second medium green body layer.And third is situated between The ceramic slurry that matter green body layer uses is identical as the ceramic slurry of second medium green body layer.

Specifically, the thickness near the third medium green body layer of the inductance green body layer of the first capacitance green body layer is more than remaining Inductance green body layer third medium green body layer thickness.And the thickness of the third medium green body of remaining inductance green body layer is homogeneous Deng.For example, the thickness near the third medium green body layer of the inductance green body layer of the first capacitance green body layer is 220 microns, remaining Inductor layer third dielectric layer 35 microns of thickness.

The method that multiple spaced electrodes are formed in third medium green body layer uses silver paste in third medium green body Silk-screen printing forms electrode on layer.The thickness of each electrode is 5 microns~12 microns.

Specifically, offering multiple electrical connection holes in third medium green body layer.Wherein, it is formed in third medium green body layer While the step of multiple spaced electrodes, the first conductive material is filled in the electrical connection hole of third medium green body layer, So that the first conductive material being filled in the electrical connection hole of third medium green body layer is by an electrode of multiple inductance green body layers It is sequentially connected in series to form an inductance, an electrode of two inductance green body layers of furthest apart is electrically connected so that two neighboring electricity Sense series connection, and make the first conductive material being filled in the electrical connection hole of third medium green body layer by each first capacitance and one Inductance is connected.The first conductive material in the electrical connection hole of third medium green body layer is filled in by the first capacitance and inductance green body The electrode of layer is electrically connected so that each first capacitance is connected with an inductance.

When the first capacitance green body layer is one, it is filled in the first conduction material of third medium green body layer being electrically connected in hole Second electrode pattern is electrically connected so that each first capacitance is connected with an inductance by material with electrode.When the first capacitance green body layer is When multiple, multiple electrical connection holes are also offered in each second medium green body layer, at this point, being formed in second medium green body layer While the step of multiple second electrode patterns, silver paste is filled in the electrical connection hole of second medium green body layer, at this point, being filled in The first conductive material in the electrical connection hole of third medium green body layer be filled in being electrically connected in hole of second medium green body layer Silver paste connects each first capacitance with an inductance.

Specifically, the first conductive material is silver paste.

Step S340：Multiple 4th medium green body layers are provided, in a third medium farthest from the first capacitance green body layer Green body layer is formed in the one side of electrode, according to one layer of the 4th medium green body layer of stacking, then is formed in the 4th medium green body layer The sequence repetitive operation of third electrode pattern to form the second capacitance green body layer of multiple stackings, and makes multiple second capacitor layers Third electrode pattern be collectively formed at least second capacitance, each second capacitance is the third of multiple second capacitance green body layers Electrode pattern is collectively formed, and makes each second capacitance and an inductance in parallel, obtains laminated construction.

Wherein, the preparation method of the 4th medium green body layer is identical as the preparation method of first medium green body layer.And the 4th is situated between The ceramic slurry that matter green body layer uses is identical as the ceramic slurry of first medium green body layer.

Wherein, it is more than remaining near the thickness of the 4th medium green body layer of the second capacitance green body layer of inductance green body layer The thickness of 4th medium green body layer of the second capacitance green body layer.For example, near the second capacitance green body layer of inductance green body layer The thickness of 4th medium green body layer is 220 microns, and the thickness 45 of the 4th medium green body layer of remaining the second capacitance green body layer is micro- Rice.

The method of formation third electrode pattern is in the 4th medium green body layer：Using silver paste silk-screen printing.Third electrode The thickness of pattern is 5 microns~12 microns.

Specifically, multiple electrical connection holes are also offered in the 4th medium green body layer, at this point, the shape in the 4th medium green body layer At third electrode pattern step while, fill the second conductive material in the electrical connection hole of the 4th medium green body layer so that The second conductive material in the electrical connection hole of the 4th medium green body is filled in by each second capacitance and an inductance in parallel.Fill out Third electrode pattern is electrically connected by the second conductive material filled in the electrical connection hole of the 4th medium green body with the electrode of inductance, with Make each second capacitance and an inductance in parallel.

Wherein, the second conductive material is silver paste.

Specifically, in order to realize the accurate right of second medium green body layer, third medium green body layer and the 4th medium green body layer Position, can open up pair in first medium green body layer, second medium green body layer, third medium green body layer and the 4th medium green body layer Position hole.

Step S350：Laminated construction is laminated, laminate is obtained.

Wherein, the step of laminated construction being laminated be specially：Using isostatic pressed method by laminated construction in 45~93 DEG C, Pressurize 3~35 minutes in 18~45MPa.

Further, before the step of laminated construction being laminated, further include：Cover board green body is provided, cover board green body is laminated It is formed in the one side of third electrode pattern in a fourth medium green body layer farthest from inductance green body layer, and cover board green body hides Cover the third electrode pattern in a 4th medium green body layer farthest from inductance green body layer.Wherein, the preparation side of lid green body Method is identical as the preparation method of first medium green body.And it prepares the ceramic slurry of lid green body and prepares first medium green body layer Ceramic slurry is identical.That is bottom plate green body layer, the first capacitance green body layer, inductance green body layer, the second capacitance green body layer and lid green body Collectively constitute laminated construction.

Step S360：Laminate is sintered, ceramic body is obtained.

Further, it is specially by the step of sintering of laminate：By laminate with 0.45~0.5 DEG C/min of heating Rate be warming up to 200 DEG C keep the temperature 5~6 hours, then with 0.45~0.5 DEG C/min of heating rate be warming up to 490 DEG C heat preservation 10~ 12 hours, then, 790~900 DEG C are warming up to 2 DEG C/min of heating rate, and heat preservation sintering 2~3 hours.Wherein, by layer Casting die is warming up to 200 DEG C with 0.45~0.5 DEG C/min of heating rate and keeps the temperature 5~6 hours, then with 0.45~0.5 DEG C/min Heating rate be warming up to the process that 490 DEG C of heat preservations 10~12 hours are dumping, the process of dumping is very heavy to low-pass filter It wants, insufficient low-pass filter bubble, deformation or the layering that can make follow-up sintering of dumping；If dumping is excessive, it is likely that The first electrode pattern in first medium green body layer, the second electrode pattern in second medium green body layer, can be resulted in The third electrode pattern on electrode and the 4th medium green body layer in three medium green body layers falls off.And since sintering process is low pass The ceramic body of filter can ensure interior at porcelain densification and the cofiring process of interior electrode and dielectric layer, the sintering schedule The synchronous of electrode and dielectric layer prevents the interior electrode in edge from " inside contracting " phenomenon occur, with electrode in realization and ceramics Matching co-firing.

Step S370：External electrode is formed on ceramic body, obtains low-pass filter.

Wherein, it is specially the step of forming external electrode on ceramic body：In the first silver layer of the both ends of ceramic body formation, and The opposite both sides of the centre of ceramic body are respectively formed the second silver layer, and external electrode is formed on ceramic body through sintering.First silver layer It is formed using the method for " dipping in silver ".Second silver layer is formed using the method that silver wheel rolling applies silver is applied.

Further include being formed on the first silver layer after forming external electrode to meet the welding requirements of low-pass filter It stacks gradually in nickel layer and tin layers on the first silver layer.Nickel layer is for heat-insulated, and tin layers are convenient for welding.Wherein, plating can be used in nickel layer The method of nickel obtains.

It can be attached with impurity either silver ink firing after being sintered due to silver paste and will produce glass phase later, influence whether nickel layer It is coated with effect, therefore, before forming nickel layer, first removal is located at the residue of the first silver layer surface.For example, using alcohol or water Clean the surface of the first silver layer.

The preparation method of above-mentioned low-pass filter is simple for process, is easy to industrialized production.And low pass prepared by the above method The 3dB cutoff frequencies of filter are higher, operating frequency range is wider, Out-of-band rejection is higher and microwave frequency band using consistency compared with It is good, and 3dB cutoff frequencies reach as high as 20000MHz.And low-pass filter prepared by the above method also helps low-pass filtering The miniaturization of device.

It is specific embodiment part below：

Embodiment 1

The preparation process of the low-pass filter of the present embodiment is as follows：

(1) it is weighed according to following mass percent：50% ceramic powder, 42% solvent, 2% plasticizer, 5.5% Binder and 0.5% dispersant, wherein ceramic powder is that the tangent value of sintered dielectric loss angle is 3.53 × 10^-4、 And the alumina-based ceramic powder that dielectric constant is 27.8, and the specific surface area of ceramic powder is 5.7m²/ g, of ceramic powder The positively charged characteristic in grain surface；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the mass ratio of ethyl alcohol and ethyl acetate is 3: 7；Plasticizer is polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 20 hours, binder is then added, after Continuous ball milling 35 hours, ball milling frequency is 100Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 60 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that two thickness are 35 microns, a thickness are 220 microns, two thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in second medium green body layer, third medium base Multiple electrical connection holes are opened up in body layer and the 4th medium green body layer, are situated between in first medium green body, second medium green body layer, third Registration holes are opened up in matter green body layer and the 4th medium green body layer.

(4) silver paste is used to form thickness in thickness for silk-screen printing on a surface of 240 microns of first medium green body layer Degree is 9 microns of first electrode pattern, obtains bottom plate green body.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body The second electrode pattern that the electrode that it is 9 microns by three interval settings and thickness that printing, which is formed, is formed, and in the second medium base Silver paste is filled in the electrical connection hole of body layer, obtains first the first capacitance green body layer；Then, in first the first capacitance green body layer Second medium green body layer be formed with that another thickness is laminated in the one side of second electrode pattern is 43 microns of second medium base Then body layer uses silver paste silk-screen printing in one side of the second medium green body layer far from first the first capacitance green body layer It is 9 microns of second electrode pattern to form thickness, and fills silver paste in the electrical connection hole of the second medium green body layer, obtains the Two the first capacitance green body layers, under the action of being filled in the silver paste in electrical connection hole of second medium green body layer, first electrode figure Three the first capacitances are collectively formed in the second electrode pattern of case and two the first capacitance green body layers, and each first capacitance is first Electrode pattern, first the first capacitance green body layer an electrode and second capacitance green body the common shape of second electrode pattern At；Wherein, by the basis of registration holes hole to realize the accurate right of multiple second medium green body layers and first medium green body layer Position.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Four spaced electrodes that silk-screen printing thickness is 9 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Four spaced electrodes that silk-screen printing thickness is 9 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer；Then, it is formed in the second medium green body of second inductance green body layer Have and the third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium base Four spaced electrodes that silk-screen printing thickness is 9 microns on body layer, meanwhile, in the electrical connection of the third medium green body layer Silver paste is filled in hole, obtains third inductance green body layer, is filled in the electrical connection hole of third medium green body layer silver paste by three The electrode of third inductance green body layer is electrically connected to form four concatenated inductance, and one that each inductance is three inductance green body layers Electrode is sequentially connected in series to be formed, and is filled in the electrical connection hole of third medium green body layer silver paste by the one of first inductance green body layer The series connection of a electrode and an electrode of third inductance green body layer and adjacent two inductance are connected, and each first capacitance It connects with an inductance.Wherein, pass through the accurate contraposition of the hole realization third medium green body layer lamination process on the basis of registration holes.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste in the 4th one side of the medium green body layer far from inductance unit green body silk-screen printing formed by Thickness is the third electrode pattern of 9 microns and spaced three electrodes composition, meanwhile, in the electricity of the 4th medium green body Silver paste is filled in connecting hole, obtains first the second capacitance green body layer；Again in the 4th medium of first the second capacitance green body layer Green body layer is formed with the 4th medium green body layer for being laminated that a layer thickness is 35 microns in the one side of third electrode pattern, and using silver Slurry silk-screen printing in the 4th medium green body layer is formed is 9 microns and spaced three electrodes form the by thickness Three electrode patterns, while silver paste is filled in the electrical connection hole of the 4th medium green body layer, obtain second the second capacitance green body Layer；Then, it is formed in the one side of third electrode pattern and is laminated in the 4th medium green body layer of second the second capacitance green body layer The 4th medium green body layer that another layer thickness is 35 microns, and formed using silver paste silk-screen printing in the 4th medium green body layer It is 9 microns by thickness and third electrode pattern that spaced three electrodes form, meanwhile, in the 4th medium green body layer Electrical connection hole in fill silver paste, obtain third the second capacitance green body layer, be filled in the electrical connection hole of the 4th medium green body layer In silver paste the third electrode pattern of three the second capacitance green body layers is electrically connected to form three the second capacitances, and each second electricity Hold and is collectively formed for an electrode of three the second capacitance green body layers, the silver being filled in the electrical connection hole of the 4th medium green body layer Slurry makes each second capacitance and an inductance in parallel.Wherein, by the basis of registration holes hole realize the 4th medium green body layer by layer The accurate contraposition of folded process.

(8) it is formed with third electrode pattern in the 4th medium green body layer of the second capacitance green body layer farthest from inductor layer Side upper layer covers body green body, and make in the 4th medium green body layer of lid green body masking third the second capacitance green body layer the Three electrode patterns, obtain laminated construction.

(9) by laminated construction using isostatic pressed method in 70 DEG C, 28MPa pressurize 15 minutes, obtain laminate.

(10) laminate is warming up to 200 DEG C with 0.5 DEG C/min of heating rate and keeps the temperature 5 hours, then with 0.5 DEG C/min Heating rate be warming up to 490 DEG C keep the temperature 10 hours, carry out dumping, be then warming up to 500 DEG C with 1 DEG C/min of heating rate, 890 DEG C are warming up to 2 DEG C/min of heating rate, and heat preservation sintering 2 hours, natural cooling cooling obtains length, width and height difference again For the ceramic body of 3.2mm, 1.6mm and 0.9mm.Then, ceramic body and zirconia cylindrical body common rotation are ground 20 hours, and Rotational frequency is 80Hz, by ceramic body chamfering.

(11) method that " dipping in silver " is respectively adopted in the both ends of ceramic body is formed into the first silver layer, and makes two the first silver layers point It is not electrically connected with the both ends of concatenated four inductance；And roll the center both sides shape for applying the method for silver in ceramic body using silver wheel is applied The second silver layer being oppositely arranged at two；Then the ceramic body of the first silver layer and the second silver layer will be formed in continuous tunnel furnace at heat Reason, finally, removes the residue of first silver layer surface at both ends, and be coated with nickel layer and tin successively respectively in the silver electrode at both ends Layer, obtains low-pass filter.

The 3dB cutoff frequencies of the low-pass filter of the present embodiment are tested using radio frequency network analyzer；And use radio frequency network Network analyzer is tested to obtain the insertion loss curve of the low-pass filter of the present embodiment, to determine the working frequency model of the present embodiment It encloses and inhibits with stopband.Wherein, Fig. 7 is the insertion loss curve of the low-pass filter of the present embodiment, as can be drawn from Figure 7 this reality The stopband of the operating frequency range, 30dB or more of applying the low-pass filter of example inhibits the stopband of range and 20dB or more to inhibit Range, wherein the 3dB cutoff frequencies of the low-pass filter of the present embodiment, the stopband inhibition model of operating frequency range, 30dB or more It encloses and the stopband of 20dB or more inhibits range to be shown in Table 1.

Embodiment 2

(1) it is weighed according to following mass percent：51% ceramic powder, 40% solvent, 2.5% plasticizer, 6% Binder and 0.5% dispersant, wherein ceramic powder is that the tangent value of sintered dielectric loss angle is 1.67 × 10^-4、 And the alumina-based ceramic powder that dielectric constant is 13.6, and the specific surface area of ceramic powder is 6m²/ g, the particle of ceramic powder The positively charged characteristic in surface；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the mass ratio of ethyl alcohol and ethyl acetate is 3:7； Plasticizer is polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 15 hours, binder is then added, after Continuous ball milling 35 hours, ball milling frequency is 90Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 30 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that two thickness are 35 microns, a thickness are 220 microns, two thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in second medium green body layer, third medium base Multiple electrical connection holes are opened up in body layer and the 4th medium green body layer, are situated between in first medium green body, second medium green body layer, third Registration holes are opened up in matter green body layer and the 4th medium green body layer.

(4) silver paste is used to form thickness in thickness for silk-screen printing on a surface of 240 microns of first medium green body layer Degree is 10 microns of first electrode pattern, obtains bottom plate green body.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body The second electrode pattern that the electrode that it is 10 microns by three interval settings and thickness that printing, which is formed, forms, and in the second medium base Silver paste is filled in the electrical connection hole of body layer, obtains first the first capacitance green body layer；Then, in first the first capacitance green body layer Second medium green body layer be formed with that another thickness is laminated in the one side of second electrode pattern is 43 microns of second medium base Then body layer uses silver paste silk-screen printing in one side of the second medium green body layer far from first the first capacitance green body layer It forms thickness and is 10 microns of second electrode pattern, and silver paste is filled in the electrical connection hole of the second medium green body layer, obtain Second the first capacitance green body layer, under the action of being filled in the silver paste in electrical connection hole of second medium green body layer, first electrode The second electrode pattern of pattern and two the first capacitance green body layers is collectively formed three the first capacitances, and each first capacitance is the One electrode pattern, first the first capacitance green body layer an electrode and second capacitance green body the common shape of second electrode pattern At；Wherein, by the basis of registration holes hole to realize the accurate right of multiple second medium green body layers and first medium green body layer Position.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Three spaced electrodes that silk-screen printing thickness is 10 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Three spaced electrodes that silk-screen printing thickness is 10 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer；Then, it is formed in the second medium green body of second inductance green body layer Have and the third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium base Three spaced electrodes that silk-screen printing thickness is 10 microns on body layer, meanwhile, in being electrically connected for the third medium green body layer It connects and fills silver paste in hole, obtain third inductance green body layer, be filled in the electrical connection hole of third medium green body layer silver paste by three The electrode of a third inductance green body layer is electrically connected to form three concatenated inductance, and each inductance is the one of three inductance green body layers A electrode is sequentially connected in series to be formed, by an electrode of first inductance green body layer and an electrode of third inductance green body layer It connects and two adjacent inductance is connected, and each first capacitance is connected with an inductance.Wherein, by using registration holes as base Realize the accurate contraposition of third medium green body layer lamination process in quasi- hole.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste in the 4th one side of the medium green body layer far from inductance unit green body silk-screen printing formed by Thickness is the third electrode pattern of 10 microns and spaced three electrodes composition, meanwhile, in the 4th medium green body Electrical connection fills silver paste in hole, obtains first the second capacitance green body layer；The 4th in first the second capacitance green body layer is situated between again Matter green body layer, which is formed in the one side of third electrode pattern, is laminated a layer thickness as 35 microns of the 4th medium green body layer, and uses Silk-screen printing formation is 10 microns by thickness to silver paste in the 4th medium green body layer and spaced three electrodes form Third electrode pattern, while filling silver paste in the electrical connection hole of the 4th medium green body layer, obtain second the second capacitance Green body layer；Then, it is formed in the one side of third electrode pattern in the 4th medium green body layer of second the second capacitance green body layer The 4th medium green body layer that another layer thickness is 35 microns is laminated, and uses silver paste silk-screen printing in the 4th medium green body layer Formation is 10 microns by thickness and spaced three electrodes form third electrode pattern, meanwhile, in the 4th medium base Silver paste is filled in the electrical connection hole of body layer, the second capacitance green body layer of third is obtained, is filled in being electrically connected for the 4th medium green body layer The third electrode pattern of three the second capacitance green body layers is electrically connected to form three the second capacitances, and each by the silver paste connect in hole Two capacitances are that an electrode of three the second capacitance green body layers is collectively formed, and are filled in the electrical connection hole of the 4th medium green body layer Silver paste make each second capacitance and an inductance in parallel.Wherein, pass through the 4th medium green body of hole realization on the basis of registration holes The accurate contraposition of layer stackup process.

(9) method pressurize 12 under conditions of 65 DEG C, 30MPa that laminated construction is used to isostatic pressed, obtains laminate.

(10) laminate is warming up to 200 DEG C with 0.45 DEG C/min of heating rate and keeps the temperature 6 hours, then with 0.45 DEG C/minute The heating rate of clock is warming up to 490 DEG C and keeps the temperature 12 hours, carries out dumping, is then warming up to 500 with 1 DEG C/min of heating rate DEG C, then it is warming up to 870 DEG C with 2 DEG C/min of heating rate, and heat preservation sintering 3 hours, natural cooling cooling obtains length, width and height The respectively ceramic body of 3.2mm, 1.6mm and 0.9mm.Then, ceramic body and the grinding 30 of zirconia cylindrical body common rotation is small When, and rotational frequency is 70Hz, by ceramic body chamfering.

(11) method that " dipping in silver " is respectively adopted in the both ends of ceramic body is formed into the first silver layer, and makes two the first silver layers point It is not electrically connected with the both ends of concatenated three inductance；And roll the center both sides shape for applying the method for silver in ceramic body using silver wheel is applied The second silver layer being oppositely arranged at two；Then the ceramic body of the first silver layer and the second silver layer will be formed in continuous tunnel furnace at heat Reason, finally, removes the residue of first silver layer surface at both ends, and be coated with nickel layer and tin successively respectively in the silver electrode at both ends Layer, obtains low-pass filter.

3dB cutoff frequencies, the work frequency of the low-pass filter of the present embodiment are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Fig. 8 is the insertion loss curve of the low-pass filter of the present embodiment, as can be drawn from Figure 8 The operating frequency range of the low-pass filter of the present embodiment, the stopband of 30dB or more inhibit range and the stopband of 20dB or more Inhibit range, wherein the stopband suppression of the 3dB cutoff frequencies, operating frequency range, 30dB or more of the low-pass filter of the present embodiment The stopband of range processed and 20dB or more inhibit range to be shown in Table 1.

Embodiment 3

(1) it is weighed according to following mass percent：52% ceramic powder, 39% solvent, 2.9% plasticizer, 5.7% binder and 0.4% dispersant, wherein ceramic powder is that the tangent value of sintered dielectric loss angle is 1.13 ×10^-4And the alumina-based ceramic powder that dielectric constant is 3.9, and the specific surface area of ceramic powder is 5.3m²/ g, ceramic powder The positively charged characteristic of particle surface of material；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the quality of ethyl alcohol and ethyl acetate Than being 3:7；Plasticizer is polyethylene glycol；Binder is polyvinyl butyral.Dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 10 hours, binder is then added, after Continuous ball milling 35 hours, ball milling frequency is 90Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 90 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that two thickness are 35 microns, a thickness are 220 microns, two thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in second medium green body layer, third medium base Multiple electrical connection holes are opened up in body layer and the 4th medium green body layer, are situated between in first medium green body, second medium green body layer, third Registration holes are opened up in matter green body layer and the 4th medium green body layer.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body Printing forms the second electrode pattern being made of the electrode that four interval settings and thickness are 10 microns, and in the second medium Silver paste is filled in the electrical connection hole of green body layer, obtains first the first capacitance green body layer；Then, in first the first capacitance green body The second medium green body layer of layer is formed with and the second medium that another thickness is 43 microns is laminated in the one side of second electrode pattern Then green body layer uses silver paste screen printing in one side of the second medium green body layer far from first the first capacitance green body layer Scopiform is 10 microns of second electrode pattern at thickness, and fills silver paste in the electrical connection hole of the second medium green body layer, obtains To second the first capacitance green body layer, under the action of being filled in the silver paste in electrical connection hole of second medium green body layer, the first electricity Four the first capacitances are collectively formed in pole figure case and the second electrode pattern of two the first capacitance green body layers, and each first capacitance is The second electrode pattern of first electrode pattern, an electrode of first the first capacitance green body layer and second capacitance green body is common It is formed；Wherein, by the basis of registration holes hole to realize the accurate of multiple second medium green body layers and first medium green body layer Contraposition.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Four spaced electrodes that silk-screen printing thickness is 10 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Four spaced electrodes that silk-screen printing thickness is 10 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer；Then, it is formed in the second medium green body of second inductance green body layer Have and the third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium base Four spaced electrodes that silk-screen printing thickness is 10 microns on body layer, meanwhile, in being electrically connected for the third medium green body layer It connects and fills silver paste in hole, obtain third inductance green body layer, be filled in the electrical connection hole of third medium green body layer silver paste by three The electrode of a third inductance green body layer is electrically connected to form four concatenated inductance, and each inductance is the one of three inductance green body layers A electrode is sequentially connected in series to be formed, and is filled in the electrical connection hole of third medium green body layer silver paste by first inductance green body layer The series connection of one electrode and an electrode of third inductance green body layer and adjacent two inductance are connected, and each first electricity Appearance is connected with an inductance.Wherein, by the basis of registration holes hole realize third medium green body layer lamination process it is accurate right Position.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste in the 4th one side of the medium green body layer far from inductance unit green body silk-screen printing formed by Thickness is the third electrode pattern of 10 microns and spaced two electrodes composition, meanwhile, in the 4th medium green body Electrical connection fills silver paste in hole, obtains first the second capacitance green body layer；The 4th in first the second capacitance green body layer is situated between again Matter green body layer, which is formed in the one side of third electrode pattern, is laminated a layer thickness as 35 microns of the 4th medium green body layer, and uses Silk-screen printing formation is 10 microns by thickness to silver paste in the 4th medium green body layer and spaced two electrodes form Third electrode pattern, while filling silver paste in the electrical connection hole of the 4th medium green body layer, obtain second the second capacitance Green body layer；Then, it is formed in the one side of third electrode pattern in the 4th medium green body layer of second the second capacitance green body layer The 4th medium green body layer that another layer thickness is 35 microns is laminated, and uses silver paste silk-screen printing in the 4th medium green body layer It is formed and is 10 microns by thickness and third electrode pattern that spaced two electrodes form, meanwhile, in the 4th medium Silver paste is filled in the electrical connection hole of green body layer, the second capacitance green body layer of third is obtained, is filled in the electricity of the 4th medium green body layer The third electrode pattern of three the second capacitance green body layers is electrically connected to form two the second capacitances by the silver paste in connecting hole, and every A second capacitance is that an electrode of three the second capacitance green body layers is collectively formed, and is filled in the electrical connection of the 4th medium green body layer Silver paste in hole makes each second capacitance and an inductance in parallel.Wherein, pass through the 4th medium of hole realization on the basis of registration holes The accurate contraposition of green body layer lamination process.

(9) by laminated construction using isostatic pressed method under conditions of 80 DEG C, 25MPa pressurize 16 minutes, be laminated Part.

(10) laminate is warming up to 200 DEG C with 0.45 DEG C/min of heating rate and keeps the temperature 5 hours, then with 0.45 DEG C/minute The heating rate of clock is warming up to 490 DEG C and keeps the temperature 10 hours, carries out dumping, is then warming up to 500 with 1 DEG C/min of heating rate DEG C, then it is warming up to 895 DEG C with 2 DEG C/min of heating rate, and heat preservation sintering 2 hours, natural cooling cooling obtains length, width and height The respectively ceramic body of 3.2mm, 1.6mm and 0.9mm.Then, ceramic body and the grinding 30 of zirconia cylindrical body common rotation is small When, and rotational frequency is 70Hz, by ceramic body chamfering.

3dB cutoff frequencies, the work frequency of the low-pass filter of the present embodiment are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Fig. 9 is the insertion loss curve of the low-pass filter of the present embodiment, as can be drawn from Figure 9 The operating frequency range of the low-pass filter of the present embodiment, the stopband of 30dB or more inhibit range and the stopband of 20dB or more Inhibit range, wherein the stopband suppression of the 3dB cutoff frequencies, operating frequency range, 30dB or more of the low-pass filter of the present embodiment The stopband of range processed and 20dB or more inhibit range to be shown in Table 1.

Embodiment 4

(1) it is weighed according to following mass percent：36% ceramic powder, 55% solvent, 1.0% plasticizer, 7.5% binder and 0.5% dispersant, wherein ceramic powder be the tangent value of sintered dielectric loss angle be 6 × 10^-4And the alumina-based ceramic powder that dielectric constant is 3, and the specific surface area of ceramic powder is 5.9m²/ g, ceramic powder The positively charged characteristic of particle surface；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the mass ratio of ethyl alcohol and ethyl acetate is 3:7；Plasticizer is polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 15 hours, binder is then added, after Continuous ball milling 15 hours, ball milling frequency is 190Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 45 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that one thickness is 35 microns, a thickness are 220 microns, a thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in second medium green body layer, third medium base Multiple electrical connection holes are opened up in body layer and the 4th medium green body layer, are situated between in first medium green body, second medium green body layer, third Registration holes are opened up in matter green body layer and the 4th medium green body layer.

(4) silver paste is used to form thickness in thickness for silk-screen printing on a surface of 240 microns of first medium green body layer Degree is 5 microns of first electrode pattern, obtains bottom plate green body.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body The second electrode pattern that the electrode that it is 5 microns by two interval settings and thickness that printing, which is formed, forms, and in the second medium base Silver paste is filled in the electrical connection hole of body layer, obtains first the first capacitance green body layer；Then, in first the first capacitance green body layer Second medium green body layer be formed with that another thickness is laminated in the one side of second electrode pattern is 43 microns of second medium base Then body layer uses silver paste silk-screen printing in one side of the second medium green body layer far from first the first capacitance green body layer It is 5 microns of second electrode pattern to form thickness, and fills silver paste in the electrical connection hole of the second medium green body layer, obtains the The second electrode pattern of two the first capacitance green body layers, first electrode pattern and two the first capacitance green body layers is collectively formed two First capacitance, and each first capacitance is first electrode pattern, an electrode of first the first capacitance green body layer and second The second electrode pattern of capacitance green body is collectively formed；Wherein, by the basis of registration holes hole to realize multiple second medium bases The accurate contraposition of body layer and first medium green body layer.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Three spaced electrodes that silk-screen printing thickness is 5 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Three spaced electrodes that silk-screen printing thickness is 5 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer, be filled in the electrical connection hole of third medium green body layer silver paste by two The electrode of a third inductance green body layer is electrically connected to form three concatenated inductance, and each inductance is the one of two inductance green body layers A electrode is sequentially connected in series to be formed, and is filled in the electrical connection hole of third medium green body layer silver paste by first inductance green body layer The series connection of one electrode and an electrode of third inductance green body layer and adjacent two inductance are connected, and each first electricity Appearance is connected with an inductance.Wherein, by the basis of registration holes hole realize third medium green body layer lamination process it is accurate right Position.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste in the 4th one side of the medium green body layer far from inductance unit green body silk-screen printing formed by Thickness is the third electrode pattern of 5 microns and spaced two electrodes composition, meanwhile, in the electricity of the 4th medium green body Silver paste is filled in connecting hole, obtains first the second capacitance green body layer；Again in the 4th medium of first the second capacitance green body layer Green body layer is formed with the 4th medium green body layer for being laminated that a layer thickness is 35 microns in the one side of third electrode pattern, and using silver Slurry silk-screen printing in the 4th medium green body layer is formed is 5 microns and spaced two electrodes form the by thickness Three electrode patterns, while silver paste is filled in the electrical connection hole of the 4th medium green body layer, obtain second the second capacitance green body Layer, the silver paste being filled in the electrical connection hole of the 4th medium green body layer are electric by the third electrode pattern of three the second capacitance green body layers Connection forms two the second capacitances, and the electrode that each second capacitance is two the second capacitance green body layers is collectively formed, and fills out The silver paste filled in the electrical connection hole of the 4th medium green body layer makes each second capacitance and an inductance in parallel.Wherein, by with The accurate contraposition of the 4th medium green body layer lamination process is realized in hole on the basis of registration holes.

(9) by laminated construction using isostatic pressed method under conditions of 45 DEG C, 45MPa pressurize 3 minutes, be laminated Part.

3dB cutoff frequencies, the work frequency of the low-pass filter of the present embodiment are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Figure 10 is the insertion loss curve of the low-pass filter of the present embodiment, can be obtained from Figure 10 The stopband of the operating frequency range, 30dB or more that go out the low-pass filter of the present embodiment inhibits range and the resistance of 20dB or more Band inhibits range, wherein the 3dB cutoff frequencies of the low-pass filter of the present embodiment, the stopband of operating frequency range, 30dB or more Inhibit the stopband of range and 20dB or more that range is inhibited to be shown in Table 1.

Embodiment 5

(1) it is weighed according to following mass percent：60% ceramic powder, 34.5% solvent, 1.0% plasticizer, 4.41% binder and 0.09% dispersant, wherein ceramic powder be the tangent value of sintered dielectric loss angle be 3 × 10^-4And the alumina-based ceramic powder that dielectric constant is 96, and the specific surface area of ceramic powder is 6.3m²/ g, ceramic powder The positively charged characteristic of particle surface；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the mass ratio of ethyl alcohol and ethyl acetate is 3:7；Plasticizer is polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 16 hours, binder is then added, after Continuous ball milling 30 hours, ball milling frequency is 50Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 90 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, a thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that four thickness are 35 microns, a thickness are 220 microns, a thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in third medium green body layer and the 4th medium Multiple electrical connection holes are opened up in green body layer, in first medium green body, second medium green body layer, third medium green body layer and the 4th Registration holes are opened up in medium green body layer.

(4) silver paste is used to form thickness in thickness for silk-screen printing on a surface of 240 microns of first medium green body layer Degree is 12 microns of first electrode pattern, obtains bottom plate green body.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body The second electrode pattern that the electrode that it is 12 microns by six interval settings and thickness that printing, which is formed, forms, obtains the first capacitance green body Layer, under the action of being filled in the silver paste in electrical connection hole of second medium green body layer, first electrode pattern and the first capacitance green body Six the first capacitances in parallel are collectively formed in the second electrode pattern of layer, and each first capacitance is first electrode pattern and first One electrode of capacitance green body layer is collectively formed；Wherein, by the basis of registration holes hole with realize second medium green body layer with The accurate contraposition of first medium green body layer.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Seven spaced electrodes that silk-screen printing thickness is 12 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Seven spaced electrodes that silk-screen printing thickness is 12 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer；Then, it is formed in the second medium green body of second inductance green body layer Have and the third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium base Seven spaced electrodes that silk-screen printing thickness is 12 microns on body layer, meanwhile, in being electrically connected for the third medium green body layer It connects and fills silver paste in hole, obtain third inductance green body layer；It is formed with again in the second medium green body of third inductance green body layer The third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium green body Seven spaced electrodes that silk-screen printing thickness is 12 microns on layer, meanwhile, in the electrical connection of the third medium green body layer Silver paste is filled in hole, obtains the 4th inductance green body layer；Finally, it is formed in the second medium green body of the 4th inductance green body layer The third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium green body Seven spaced electrodes that silk-screen printing thickness is 12 microns on layer, meanwhile, in the electrical connection of the third medium green body layer Silver paste is filled in hole, obtains the 5th inductance green body layer, wherein being filled in silver paste in the electrical connection hole of third medium green body layer will The electrode of five third inductance green body layers is electrically connected to form seven concatenated inductance, and each inductance is five inductance green body layers One electrode is sequentially connected in series to be formed, and is filled in the electrical connection hole of third medium green body layer silver paste by first inductance green body layer An electrode and third inductance green body layer an electrode series connection and adjacent two inductance are connected, and each first Capacitance is connected with an inductance.Wherein, by the basis of registration holes hole realize third medium green body layer lamination process it is accurate Contraposition.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste, silk-screen printing forms thickness in the 4th one side of the medium green body layer far from inductance unit green body Degree is the third electrode pattern of 12 microns and spaced three electrodes composition, meanwhile, in the electricity of the 4th medium green body Silver paste is filled in connecting hole, obtains first the second capacitance green body layer；Again in the 4th medium of first the second capacitance green body layer Green body layer is formed with the 4th medium green body layer for being laminated that a layer thickness is 35 microns in the one side of third electrode pattern, and using silver Silk-screen printing formation is 12 microns by thickness to slurry in the 4th medium green body layer and spaced three electrodes form Third electrode pattern, while silver paste is filled in the electrical connection hole of the 4th medium green body layer, obtain second the second capacitance base Body layer is filled in the silver paste in the electrical connection hole of the 4th medium green body layer by the third electrode pattern of two the second capacitance green body layers Three the second capacitances are electrically connected to form, and the electrode that each second capacitance is three the second capacitance green body layers is collectively formed, The silver paste being filled in the electrical connection hole of the 4th medium green body layer makes each second capacitance and an inductance in parallel.Wherein, pass through The accurate contraposition of the 4th medium green body layer lamination process is realized in hole on the basis of registration holes.

(9) by laminated construction using isostatic pressed method under conditions of 93 DEG C, 18MPa pressurize 35 minutes, be laminated Part.

(10) laminate is warming up to 200 DEG C with 0.5 DEG C/min of heating rate and keeps the temperature 5 hours, then with 0.5 DEG C/min Heating rate be warming up to 490 DEG C keep the temperature 10 hours, carry out dumping, be then warming up to 500 DEG C with 1 DEG C/min of heating rate, 950 DEG C are warming up to 2 DEG C/min of heating rate, and heat preservation sintering 2 hours, natural cooling cooling obtains length, width and height difference again For the ceramic body of 3.2mm, 1.6mm and 0.9mm.Then, ceramic body and zirconia cylindrical body common rotation are ground 20 hours, and Rotational frequency is 80Hz, by ceramic body chamfering.

(11) method that " dipping in silver " is respectively adopted in the both ends of ceramic body is formed into the first silver layer, and makes two the first silver layers point It is not electrically connected with the both ends of concatenated seven inductance；And roll the center both sides shape for applying the method for silver in ceramic body using silver wheel is applied The second silver layer being oppositely arranged at two；Then the ceramic body of the first silver layer and the second silver layer will be formed in continuous tunnel furnace at heat Reason, finally, removes the residue of first silver layer surface at both ends, and be coated with nickel layer and tin successively respectively in the silver electrode at both ends Layer, obtains low-pass filter.

3dB cutoff frequencies, the work frequency of the low-pass filter of the present embodiment are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Figure 11 is the insertion loss curve of the low-pass filter of the present embodiment, can be obtained from Figure 11 The stopband of the operating frequency range, 30dB or more that go out the low-pass filter of the present embodiment inhibits range and the resistance of 20dB or more Band inhibits range, wherein the 3dB cutoff frequencies of the low-pass filter of the present embodiment, the stopband of operating frequency range, 30dB or more Inhibit the stopband of range and 20dB or more that range is inhibited to be shown in Table 1.

Embodiment 6

(1) it is weighed according to following mass percent：36% ceramic powder, 50.6% solvent, 4.0% plasticizer, 8.5% binder and 0.9% dispersant, wherein ceramic powder be the tangent value of sintered dielectric loss angle be 5 × 10^-4And the alumina-based ceramic powder that dielectric constant is 50；Solvent is the mixture of ethyl alcohol and ethyl acetate, and ethyl alcohol and second The mass ratio of acetoacetic ester is 3:7；Plasticizer is polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(2) by above-mentioned ceramic powder, solvent, plasticizer and dispersant ball milling 15 hours, binder is then added, after Continuous ball milling 25 hours, ball milling frequency is 150Hz, obtains ceramic slurry.

(3) ceramic slurry is stood 80 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The 4th medium green body layer that third medium green body layer that three thickness are 35 microns, a thickness are 220 microns, two thickness are 45 microns of the 4th medium green body layer and thickness is 240 trifling lid green bodies, and in second medium green body layer, third medium base Multiple electrical connection holes are opened up in body layer and the 4th medium green body layer, are situated between in first medium green body, second medium green body layer, third Registration holes are opened up in matter green body layer and the 4th medium green body layer.

(4) silver paste is used to form thickness in thickness for silk-screen printing on a surface of 240 microns of first medium green body layer Degree is 8 microns of first electrode pattern, obtains bottom plate green body.

(5) being formed with one thickness of stacking in the one side of first electrode pattern in the first medium green body layer of bottom plate green body is Then 43 microns of second medium green body layer uses silver paste silk screen in the one side of the second medium green body layer far from bottom plate green body Printing forms thickness and is 8 microns of second electrode pattern, and fills silver paste in the electrical connection hole of the second medium green body layer, obtains To first the first capacitance green body layer；Then, it is formed with second in the second medium green body layer of first the first capacitance green body layer The second medium green body layer that another thickness is 43 microns is laminated in the one side of electrode pattern, then, in the second medium green body Layer uses silver paste silk-screen printing to form thickness as 8 microns of second electrode figure in the one side far from first the first capacitance green body layer Case, and silver paste is filled in the electrical connection hole of the second medium green body layer, obtain second the first capacitance green body layer, first electrode First capacitance is collectively formed in the second electrode pattern of pattern and two the first capacitance green body layers, and the first capacitance is the first electricity The second electrode pattern of pole figure case, the second electrode pattern of the first capacitance green body layer and second capacitance green body is collectively formed；Its In, by the basis of registration holes hole to realize the accurate contraposition of second medium green body layer and first medium green body layer.

(6) it is formed with first layer in the one side of second electrode pattern in a second medium green body layer farthest from bottom plate green body The third medium green body layer that folded thickness is 220 microns, using silver paste in the third medium green body layer far from the first capacitor cell base Two spaced electrodes that silk-screen printing thickness is 8 microns on the surface of body, while in the third medium green body layer It is electrically connected the filling silver paste in hole, obtains first inductance green body layer；Then, in the second medium green body of first inductance green body layer It is formed with the third medium green body layer for being laminated that a layer thickness is 35 microns in the one side of electrode, and using silver paste in the third medium Two spaced electrodes that silk-screen printing thickness is 8 microns in green body layer, while being electrically connected in the third medium green body layer It connects and fills silver paste in hole, obtain second inductance green body layer；Then, it is formed in the second medium green body of second inductance green body layer Have and the third medium green body layer that another layer thickness is 35 microns is laminated in the one side of electrode, and using silver paste in the third medium base Two spaced electrodes that silk-screen printing thickness is 8 microns on body layer, meanwhile, in the electrical connection of the third medium green body layer Silver paste is filled in hole, obtains third inductance green body layer；Again electricity is formed in the second medium green body of third inductance green body layer The third medium green body layer that another layer thickness is 35 microns is laminated in the one side of pole, and using silver paste in the third medium green body layer Two spaced electrodes that upper silk-screen printing thickness is 8 microns, meanwhile, in the electrical connection hole of the third medium green body layer Silver paste is filled, the 4th inductance green body layer is obtained, wherein is filled in the electrical connection hole of third medium green body layer silver paste by four The electrode of third inductance green body layer is electrically connected to form two concatenated inductance, and one that each inductance is five inductance green body layers Electrode is sequentially connected in series to be formed, and the first capacitance is connected with an inductance.Wherein, pass through the hole realization third medium on the basis of registration holes The accurate contraposition of green body layer lamination process.

(7) in a third medium green body layer farthest from the first capacitance green body layer stacking thickness be 220 microns the Four medium green body layers, using silver paste, silk-screen printing forms thickness in the 4th one side of the medium green body layer far from inductance unit green body The third electrode pattern that degree is 8 microns, meanwhile, silver paste is filled in the electrical connection hole of the 4th medium green body, obtains first Second capacitance green body layer；Again the one of third electrode pattern is formed in the 4th medium green body layer of first the second capacitance green body layer The 4th medium green body layer that a layer thickness is 35 microns is laminated on face, and uses silver paste screen printing in the 4th medium green body layer Scopiform is 8 microns of third electrode patterns at thickness, while filling silver paste in the electrical connection hole of the 4th medium green body layer, is obtained Second the second capacitance green body layer；Then, it is formed with third electricity in the 4th medium green body layer of second the second capacitance green body layer The 4th medium green body layer that another layer thickness is 35 microns is laminated in the one side of pole figure case, and using silver paste in the 4th medium base Silk-screen printing forms the third electrode pattern that thickness is 8 microns on body layer, meanwhile, in the electrical connection hole of the 4th medium green body layer Middle filling silver paste obtains the second capacitance green body layer of third, and the silver paste being filled in the electrical connection hole of the 4th medium green body layer will The third electrode pattern of three the second capacitance green body layers is electrically connected to form second capacitance, wherein is filled in the 4th medium base Silver paste in the electrical connection hole of body layer makes the second capacitance and an inductance in parallel.Wherein, by the basis of registration holes hole realize The accurate contraposition of 4th medium green body layer lamination process.

(9) by laminated construction using isostatic pressed method under conditions of 60 DEG C, 40MPa pressurize 10 minutes, be laminated Part.

(10) laminate is warming up to 200 DEG C with 0.45 DEG C/min of heating rate and keeps the temperature 5 hours, then with 0.45 DEG C/minute The heating rate of clock is warming up to 490 DEG C and keeps the temperature 10 hours, carries out dumping, is then warming up to 500 with 1 DEG C/min of heating rate DEG C, then it is warming up to 790 DEG C with 2 DEG C/min of heating rate, and heat preservation sintering 2 hours, natural cooling cooling obtains length, width and height The respectively ceramic body of 3.2mm, 1.6mm and 0.85mm.Then, ceramic body and the grinding 30 of zirconia cylindrical body common rotation is small When, and rotational frequency is 70Hz, by ceramic body chamfering.

(11) method that " dipping in silver " is respectively adopted in the both ends of ceramic body is formed into the first silver layer, and makes two the first silver layers point It is not electrically connected with the both ends of concatenated two inductance；And roll the center both sides shape for applying the method for silver in ceramic body using silver wheel is applied The second silver layer being oppositely arranged at two；Then the ceramic body of the first silver layer and the second silver layer will be formed in continuous tunnel furnace at heat Reason, finally, removes the residue of first silver layer surface at both ends, and be coated with nickel layer and tin successively respectively in the silver electrode at both ends Layer, obtains low-pass filter.

3dB cutoff frequencies, the work frequency of the low-pass filter of the present embodiment are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Figure 12 is the insertion loss curve of the low-pass filter of the present embodiment, can be obtained from Figure 12 The stopband of the operating frequency range, 30dB or more that go out the low-pass filter of the present embodiment inhibits range and the resistance of 20dB or more Band inhibits range, wherein the 3dB cutoff frequencies of the low-pass filter of the present embodiment, the stopband of operating frequency range, 30dB or more Inhibit the stopband of range and 20dB or more that range is inhibited to be shown in Table 1.

Comparative example 1

The preparation process of the low-pass filter of comparative example 1 is as follows：

(1) 36% ceramic powder, 50.6% solvent, 4.0% plasticizer, 8.5% binder and 0.9% point Powder, wherein ceramic powder is that the tangent value of sintered dielectric loss angle is 5 × 10^-4And the aluminium oxide that dielectric constant is 50 Based ceramic powder material；Solvent is the mixture of ethyl alcohol and ethyl acetate, and the mass ratio of ethyl alcohol and ethyl acetate is 3:7；Plasticizer For polyethylene glycol；Binder is polyvinyl butyral, and dispersant is oleic acid.

(3) ceramic slurry is stood 80 minutes, tape casting is respectively formed first Jie that a thickness is 240 microns Third medium green body layer that second medium green body layer that matter green body layer, two thickness are 43 microns, a thickness are 220 microns, The third medium green body layer and thickness that three thickness are 35 microns are 240 trifling lid green bodies, and in second medium green body layer With multiple electrical connection holes are opened up in third medium green body layer, in first medium green body, second medium green body layer and third medium Registration holes are opened up in green body layer.

(7) it is formed on the side of electrode and is laminated in the farthest third medium green body layer of the bottom plate green body farthest from inductor layer Lid green body, and lid green body is made to cover the electrode in the third medium green body layer of the 4th third medium green body layer, it is folded Layer structure.

(8) by laminated construction using isostatic pressed method under conditions of 60 DEG C, 40MPa pressurize 10 minutes, be laminated Part.

(9) laminate is warming up to 200 DEG C with 0.45 DEG C/min of heating rate and keeps the temperature 5 hours, then with 0.45 DEG C/minute The heating rate of clock is warming up to 490 DEG C and keeps the temperature 10 hours, carries out dumping, is then warming up to 500 with 1 DEG C/min of heating rate DEG C, then it is warming up to 790 DEG C with 2 DEG C/min of heating rate, and heat preservation sintering 2 hours, natural cooling cooling obtains length, width and height The respectively ceramic body of 3.2mm, 1.6mm and 0.85mm.Then, ceramic body and the grinding 30 of zirconia cylindrical body common rotation is small When, and rotational frequency is 70Hz, by ceramic body chamfering.

(10) method that " dipping in silver " is respectively adopted in the both ends of ceramic body is formed into the first silver layer, and makes two the first silver layers point It is not electrically connected with the both ends of concatenated two inductance；And roll the center both sides shape for applying the method for silver in ceramic body using silver wheel is applied The second silver layer being oppositely arranged at two；Then the ceramic body of the first silver layer and the second silver layer will be formed in continuous tunnel furnace at heat Reason, finally, removes the residue of first silver layer surface at both ends, and be coated with nickel layer and tin successively respectively in the silver electrode at both ends Layer, obtains low-pass filter.

3dB cutoff frequencies, the work frequency of the low-pass filter of comparative example 1 are obtained using 1 identical test method of embodiment Rate range and stopband inhibit, wherein Figure 13 is the insertion loss curve of the low-pass filter of comparative example 1, can be obtained from Figure 13 Go out operating frequency range, the 30dB of the low-pass filter of comparative example 1 inhibits the stopband of range and 20dB or more to inhibit with stopband Range, wherein the 3dB cutoff frequencies of the low-pass filter of comparative example 1, the stopband inhibition model of operating frequency range, 30dB or more It encloses and the stopband of 20dB or more inhibits range to be shown in Table 1.

What table 1 indicated be the 3dB cutoff frequencies of low-pass filter of Examples 1 to 6 and comparative example 1, operating frequency range, The stopband of 30dB or more inhibits the stopband of range and 20dB or more to inhibit range.

Table 1

As can be seen from Table 1：Comparative example 1 and the 3dB cutoff frequencies of embodiment 6 are 270MHz, and comparative example 1 reaches Frequency when initial 20dB is 990MHz, and frequency when embodiment 6 is up to initial 20dB is only 370MHz.Therefore, embodiment 6 is low Intermediate zone between the passband and stopband of bandpass filter has more precipitous attenuation characteristic.

The 20dB stopbands that are more than of the low-pass filter of comparative example 1 inhibit frequency range for 990~7800MHz；And embodiment 6 Low-pass filter be more than 20dB stopbands inhibit frequency range be 3700~12000MHz.Therefore, the low-pass filter of embodiment 6 Stopband inhibit frequency range it is wider.

It is computed, the ratio of the minimum value and 3dB cutoff frequencies of the stopband inhibition of the 20dB of the low-pass filter of comparative example 1 It is 3.67, and minimum value and the ratio of 3dB cutoff frequencies that the stopband of the 20dB of the low-pass filter of embodiment 6 inhibits are 1.37, it is much smaller than comparative example 1, illustrates that the stopband of embodiment 6 inhibits, i.e., the low-pass filter of embodiment 6 is reached from 3dB dot frequencies The slope of initial 20dB dot frequencies is relatively steep, and the intermediate zone between passband and stopband has more precipitous attenuation characteristic, and range is more Wide stopband inhibits frequency, more excellent stopband rejection characteristic.And the stopband suppression of the 20dB of the low-pass filter of Examples 1 to 5 The minimum value of system and the ratio of 3dB cutoff frequencies are respectively 1.55,1.12,1.07,1.07 and 1.5, i.e., Examples 1 to 5 is low Slope of the bandpass filter from 3dB dot frequencies up to initial 20dB dot frequencies is relatively steep, and the intermediate zone between passband and stopband also has More precipitous attenuation characteristic, the broader stopband of range inhibit frequency, more excellent stopband rejection characteristic.

Each technical characteristic of embodiment described above can be combined arbitrarily, to keep description succinct, not to above-mentioned reality It applies all possible combination of each technical characteristic in example to be all described, as long as however, the combination of these technical characteristics is not deposited In contradiction, it is all considered to be the range of this specification record.

Several embodiments of the invention above described embodiment only expresses, the description thereof is more specific and detailed, but simultaneously It cannot therefore be construed as limiting the scope of the patent.It should be pointed out that coming for those of ordinary skill in the art It says, without departing from the inventive concept of the premise, various modifications and improvements can be made, these belong to the protection of the present invention Range.Therefore, the protection domain of patent of the present invention should be determined by the appended claims.

Claims

1. a kind of low-pass filter, which is characterized in that including ceramic body, the ceramic body includes bottom plate and stacks gradually in described The first capacitor layers, multiple inductor layers on bottom plate and multiple second capacitor layers, wherein：

First capacitor layers are laminated on the first medium layer, and first capacitor layers include second dielectric layer and are formed in Second electrode pattern in the second dielectric layer, the second electrode pattern are collectively formed at least with the first electrode pattern One the first capacitance, and each first capacitance is that the first electrode pattern is collectively formed with the second electrode pattern；

Multiple inductor layers are stacked gradually in the second dielectric layer, and each inductor layer includes third dielectric layer and shape The electrode at multiple intervals on third dielectric layer described in Cheng Yu, multiple electrodes of multiple inductor layers are electrically connected to form more A concatenated inductance, and an electrode of multiple inductor layers connects to form an inductance, wherein it is each described First capacitance is connected with an inductance；

Multiple second capacitor layers are stacked gradually on a third dielectric layer farthest from first capacitor layers, often A second capacitor layers include the 4th dielectric layer and the third electrode pattern that is formed on the 4th dielectric layer, multiple described At least second capacitance is collectively formed in the third electrode pattern of second capacitor layers, and each second capacitance is multiple The third electrode pattern of second capacitor layers is collectively formed, each second capacitance and an inductance in parallel.

2. low-pass filter according to claim 1, which is characterized in that each inductor layer further includes multiple is arranged in First electric binding post of the third dielectric layer, first electric binding post by an electrode of multiple inductor layers according to Secondary series connection forms an inductance, and first electric binding post is by an electricity of two inductor layers of furthest apart Pole is electrically connected so that the two neighboring inductance series connection, and first electric binding post will each first capacitance and an institute State inductance series connection；Each second capacitor layers further include multiple the second electric binding posts for being arranged in the 4th dielectric layer, institute State the second electric binding post the third electrode pattern of multiple second capacitor layers is electrically connected so that with the inductance it is each Second capacitance and an inductance in parallel.

3. low-pass filter according to claim 1, which is characterized in that first capacitor layers be it is multiple, it is multiple described First capacitor layers are stacked gradually on the first medium layer, the second electrode pattern of multiple first capacitor layers and institute At least first capacitance is collectively formed in the first electrode pattern for stating bottom plate, and each first capacitance is multiple described the The second electrode pattern of one capacitor layers is collectively formed with the first electrode pattern, wherein multiple inductor layers are successively It is laminated in the second dielectric layer of first capacitor layers farthest from the bottom plate.

4. low-pass filter according to claim 1, which is characterized in that the 4th dielectric layer, the third dielectric layer, The material of the second dielectric layer and the first medium layer is identical ceramic material.

5. low-pass filter according to claim 1, which is characterized in that the 4th dielectric layer, the third dielectric layer, The tangent value of the second dielectric layer and the dielectric loss angle of the first medium layer is respectively less than or is equal to 6 × 10^-4。

6. low-pass filter according to claim 1, which is characterized in that the 4th dielectric layer, the third dielectric layer, The second dielectric layer and the dielectric constant of the first medium layer are 3~96.

7. a kind of preparation method of low-pass filter, which is characterized in that include the following steps：

First medium green body layer is provided, first electrode pattern is formed on a surface of the first medium green body layer, obtains Bottom plate green body；

Second medium green body layer is provided, is laminated in the one side that the first medium green body layer is formed with the first electrode pattern The second medium green body layer, and second electrode pattern is formed in the second medium green body layer, and make the second electrode At least first capacitance is collectively formed with the first electrode pattern in pattern, and each first capacitance is first electricity Pole figure case is collectively formed with the second electrode pattern, obtains the first capacitance green body layer；

Multiple third medium green body layers are provided, the one side of the second electrode pattern is formed in the second medium green body layer On, according to one layer of third medium green body layer of stacking, then formed in the third medium green body layer multiple spaced The sequence repetitive operation of electrode to form the inductance green body layer of multiple stackings, and makes multiple institutes of multiple inductance green body layers It states electrode and is electrically connected to form multiple concatenated inductance, an electrode of multiple inductance green body layers connects to form an institute Inductance is stated, and each first capacitance is made to connect with an inductance；

Multiple 4th medium green body layers are provided, in the third medium green body layer farthest from the first capacitance green body layer It is formed in the one side of the electrode, according to one layer of the 4th medium green body layer of stacking, then in the 4th medium green body layer The upper sequence repetitive operation for forming third electrode pattern to form the second capacitance green body layer of multiple stackings, and makes multiple described At least second capacitance is collectively formed in the third electrode pattern of second capacitance green body layer, and each second capacitance is more The third electrode pattern of a second capacitance green body layer is collectively formed, and makes described in each second capacitance and one Inductance in parallel obtains laminated construction；

The laminated construction is laminated, laminate is obtained；

The laminate is sintered, ceramic body is obtained；And

External electrode is formed on the ceramic body, obtains low-pass filter.

8. the preparation method of low-pass filter according to claim 7, which is characterized in that the third medium green body layer and Multiple electrical connection holes are offered in the 4th medium green body layer；Wherein, it is formed in the third medium green body layer multiple While the step of the spaced electrode, fills and first lead in the electrical connection hole of the third medium green body layer Electric material, and make first conductive material being filled in the electrical connection hole of the third medium green body layer by multiple institutes An electrode for stating inductance green body layer is sequentially connected in series to form an inductance, and by two inductance of furthest apart One electrode of green body layer is electrically connected so that the two neighboring inductance series connection, and makes to be filled in the third medium green body First conductive material in the electrical connection hole of layer connects each first capacitance with an inductance；Institute While stating the step for forming the third electrode pattern in the 4th medium green body layer, described in the 4th medium green body layer Electrical connection fills the second conductive material in hole, so as to be filled in described the in the electrical connection hole of the 4th medium green body The third electrode pattern and the inductance are electrically connected so that each second capacitance and an electricity by two conductive materials Sense is in parallel.

9. the preparation method of low-pass filter according to claim 7, which is characterized in that obtain the first capacitance green body Layer the step of be specially：Multiple second medium green body layers are provided, described first is formed in the first medium green body layer In the one side of electrode pattern, according to one layer of second medium green body layer of stacking, then formed in the second medium green body layer The sequence repetitive operation of the second electrode pattern is formed with forming multiple stack gradually in the first medium green body layer The first capacitance green body layer in the one side of first electrode pattern is stated, and makes second electricity of multiple first capacitance green body layers At least first capacitance is collectively formed with the first electrode pattern in pole figure case, and each first capacitance is multiple The second electrode pattern of the first capacitance green body layer is collectively formed with the first electrode pattern；Wherein, from described A farthest second medium green body layer of bottom plate green body is formed in the one side of the second electrode pattern, according to stacking one The layer third medium green body layer, then form in the third medium green body layer sequence of multiple spaced electrodes Repetitive operation.

10. the preparation method of low-pass filter according to claim 7, which is characterized in that the laminated construction to be laminated The step of be specially：Using the pressurize 3 under conditions of 45~93 DEG C, 18~45MPa by the laminated construction of the method for isostatic pressed ~35 minutes.