CN201430049Y - Slice type low-temperature co-fired ceramic type common mode filter - Google Patents

Abstract

The utility model relates to a slice type low-temperature co-fired ceramic type common mode filter, which comprises a low-temperature co-fired ceramic body made through together overlapping a cast ceramic belt formed through the doctor blade, n layers of left coils and right coils are printed in the low-temperature co-fired ceramic body, the n>=5, and the nth layer and the first layer are respectively pin layers. The filter is characterized in that the joints that one ends of left coils of the lower layer are connected with one ends of the right coils of the upper layer are mutually staggeredwith the joints that one ends of the left coils of the upper layer are connected with one ends of the right coils of the higher upper layer through a joint corner part, and the joints that the other ends of the right coils of the lower layer are connected with the other ends of the left coils on the upper layer are mutually staggered with the joints that the other ends of the right coils of the upper layer and the other ends of the left coils of the higher upper layer through the joint corner part. The filter has the characteristics of more ideal high-frequency performance, small differential-mode impedance and low manufacturing cost.

Description

The chip low temperature co-fired ceramic co-mode filter

One. technical field

The utility model relates to a kind of temperature co-fired ceramic common mode filter that the electronic equipment model is disturbed that is used to eliminate.

Two. background technology

Present plate type common mode filter has two big primary categories, is respectively multilayer sheet type and Wound-rotor type, and the electrical property of Wound-rotor type filter is better, but cost is higher, is not suitable for using for electronic product on a large scale.And one of multilayer sheet type is for adopting the ferrite structure of double-deck manifold type, because the characteristic of Ferrite Material itself, caused its high-frequency loss excessive, when device when high band uses, useful difference mode signal is caused greatly decay, influence circuit performance, thereby only be applicable to than low-frequency range; On the other hand, the Ferrite Material dielectric constant is higher, in order to satisfy the characteristic impedance demand of common-mode filter, the inductance of its spiral form need adopt minimum live width and distance between centers of tracks, therefore can't make of common thick-film printed technology, general thin-film technique or the meticulous thick-film technique of adopting made, and production cost rises significantly.

Another kind of monolithic multilayer structure adopts LTCC structure (as shown in Figure 1), and the high frequency performance of its material own is good, and production cost is low, can produce in a large number.But owing to be subjected to the restriction of self structure, and the influence of processing line machining accuracy, its impedance operator is poorer than the above two, and the differential mode impedance can't effectively be reduced to the requirement of special requirement.This just makes when signal passes through common-mode filter that signal receiving end can't effectively receive signal.Do not reach filtering noise, by the requirement of signal.

LTCC (LTCC) technology is a kind of unsintered curtain coating ceramic material to be stacked in the multilayer circuit of making together, in the company of printing conductor, element and circuit are arranged, and this structure is burnt till an integrated form ceramic multilayer material.

Three. summary of the invention

The purpose of this utility model is to provide the chip low temperature co-fired ceramic co-mode filter that a kind of differential mode impedance is little, production cost is low.

To achieve these goals, the technical solution of the utility model is: the chip low temperature co-fired ceramic co-mode filter, the green band that it is become by curtain coating is stacked in makes the LTCC body together, be printed with n layer left coil and right coil in the LTCC body, n 〉=5, n layer, the 1st layer are respectively the pin layer, and (annotate: one deck of going up most shown in Fig. 2 is low n layer, i.e. orlop; Be because of Fig. 4-6 be n layer figure); One end of the left coil of following one deck is linked to each other by joint with an end of the right coil of last layer and (illustrates: among Fig. 2, figure coupling place is an end, the joint is the other end in the figure), the other end of the right coil of last layer is linked to each other by joint with the other end of last again left coil; It is characterized in that: the joint that the joint that an end of an end of the left coil of following one deck and the right coil of last layer is connected and an end of the left coil of last layer are connected with an end of the right coil of last layer is again opened by the joint corner part is interlaced, and the joint that the joint that the other end of the other end of the right coil of following one deck and the left coil of last layer is connected and the other end of the right coil of last layer are connected with the other end of the left coil of last layer is again opened by the joint corner part is interlaced.

It is overlapped over interlaced that described n layer left coil and right coil, the left coil of adjacent layer and right coil remove the joint corner part.

Described n layer left coil and right coil, the left coil of one deck and the both ends of right coil are right angle portion, then the both ends of left coil of another adjacent with it layer and right coil are respectively the joint corner part, the two joint corner parts at the left coil two ends of another layer are opposite with the corner direction of the two joint corner parts at right coil two ends and leave spacing, and the corner direction of the two joint corner parts at the left coil two ends of another layer is identical.

The beneficial effects of the utility model are:

1), owing to adopted high Q value, low-loss low-temperature co-burning ceramic material, the S of resulting common-mode filter ₂₁Parameter is not subjected to the influence of frequency substantially within the scope of 1GHz, its value is minimum; Compare with ferrite, its performance as shown in Figure 5, high frequency performance of the present utility model is even more ideal.

2), the neighbouring coupling layer of the structure of traditional low temperature co-fired ceramic co-mode filter must depart from certain distance (joint employing parallel construction), with joint (via hole) short circuit of avoiding connecting levels, the performance of this structure is fixed against the distance between centers of tracks level of processing of processing line to a great extent, the area of Non-overlapping Domain Z is big more, then the area of the coupling regime of coil formation is more little, electromagnetic leakage is many more, and the differential mode impedance of device is also just big more, and performance reduces.

The utility model joint has adopted that corner part is interlaced to be opened, the coil overwhelming majority overlaids of levels, and being staggeredly stacked of neighbouring two-layer repetition, the area of Non-overlapping Domain Z is little; Can satisfy the inductance value requirement of single inductance on the one hand, guarantee enough stiffness of couplings between two coupling inductances, obtain not being subjected to the stiffness of coupling of processes horizontal constraints; On the other hand, reduced electromagnetic leakage, obtained differential mode impedance behavior (the differential mode impedance is less) preferably, can not cause loss signal.

3), the utility model joint has adopted that corner part is interlaced to be opened, the area of Non-overlapping Domain Z is little, thereby avoided the minimum line pitch problems dexterously, the area of coupling regime is not subjected to the restriction of processing line spacing level and reduces, distance between centers of tracks is required to reduce, the processes difficulty is low, and common thick film screen printing technological level can reach processing request.Under the processing conditions of peer-level, performance is than traditional low temperature co-fired ceramic co-mode filter excellent performance, as shown in Figure 6.

4), because the ceramic-type filter in actual process is made, is printed conductor slurry on ceramic substrate, with low cost; Because employed each layer structure of the utility model alternately repeats, only need a spot of silk screen to get final product simultaneously, reduced the mask expense, production cost reduces greatly.

Description of drawings

Fig. 1 is the vertical view of traditional low temperature co-fired ceramic co-mode filter structure.

Fig. 2 is a structural representation of the present utility model.

Fig. 3 is a vertical view of the present utility model.

Fig. 4-the 1st, the 1st layer of figure of preparation process of the present utility model;

Fig. 4-the 2nd, the 2nd layer of figure of preparation process of the present utility model;

Fig. 4-the 3rd, the odd-level figure of preparation process the 2nd to n-1 of the present utility model (natural numbers of n 〉=5);

Fig. 4-the 4th, the even level figure of preparation process the 2nd to n-1 of the present utility model;

Fig. 4-the 5th, preparation process n-1 layer figure of the present utility model (illustrate: when n-1 was even number, Fig. 4-5 was Fig. 4-4);

Fig. 4-the 6th, preparation process n layer figure of the present utility model.

Fig. 5 is the poor common mode S parameter comparison diagram that chip low temperature co-fired ceramic co-mode filter of the present utility model is compared with ferrite device.

Fig. 6 is chip low temperature co-fired ceramic co-mode filter of the present utility model and the impedance behavior comparison diagram of traditional low temperature co-fired ceramic co-mode filter under equal process conditions.

Fig. 7 (a) is the difference mode signal equivalent circuit diagram.

Fig. 7 (b) is the common-mode signal equivalent circuit diagram

Among the figure: 1-LTCC body, the left coil that 2-is the 1st layer, the right coil that 3-is the 1st layer, the left coil of 4-n layer, the left coil of 5-n-1 layer, 6-joint corner part, the right coil of 7-n layer, 8-joint, the right coil of 9-n-1 layer.

Embodiment

As Fig. 2, shown in Figure 3, (n is 7 to the chip low temperature co-fired ceramic co-mode filter in this example, every layer printing is shown in Fig. 4-1, Fig. 4-2, Fig. 4-3, Fig. 4-4, Fig. 4-5, Fig. 4-6), the green band that it is become by curtain coating is stacked in makes LTCC body 1 together, be printed with 7 layers of left coil and right coil in the LTCC body, the 7th layer, the 1st layer is respectively the pin layer; One end of the 7th layer left coil 4 is linked to each other by joint 8 with an end of the 6th layer right coil 9 and (illustrates: among Fig. 2, figure coupling place is an end, the joint is the other end in the figure, and pin is the outer end), the other end of the 6th layer right coil 9 is linked to each other by joint with the other end of the 5th layer left coil; The other end of the 7th layer right coil 7 is linked to each other by joint with the other end of the 6th layer left coil 5, and an end of the 6th layer left coil 5 is linked to each other by joint with an end of the 5th layer right coil; The outer end of the 7th layer right coil 7 is a pin, and the outer end of the 7th layer left coil 4 is a pin;

One end of the 5th layer left coil is linked to each other by joint with an end of the 4th layer right coil, and the other end of the 4th layer right coil is linked to each other by joint with the other end of the 3rd layer left coil; The other end of the 5th layer right coil is linked to each other by joint with the other end of the 4th layer left coil, and an end of the 4th layer left coil is linked to each other by joint with an end of the 3rd layer right coil;

One end of the 4th layer left coil is linked to each other by joint with an end of the 3rd layer right coil, and the other end of the 3rd layer right coil is linked to each other by joint with the other end of the 2nd layer left coil; The other end of the 4th layer right coil is linked to each other by joint with the other end of the 3rd layer left coil, and an end of the 3rd layer left coil is linked to each other by joint with an end of the 2nd layer right coil;

One end of the 3rd layer left coil is linked to each other by joint with an end of the 2nd layer right coil, and the other end of the 2nd layer right coil is linked to each other by joint with the other end of the 1st layer left coil; The other end of the 3rd layer right coil is linked to each other by joint with the other end of the 2nd layer left coil, and an end of the 2nd layer left coil is linked to each other by joint with an end of the 1st layer right coil; The outer end of the 1st layer left coil is a pin, and the outer end of the 1st layer right coil is a pin.

The characteristics of the utility model embodiment are: an end of the 7th layer left coil 4 is a joint corner part 6, the other end of the 7th layer right coil 7 is the joint corner part, and the joint corner part 6 of the 7th layer left coil 4 is opposite with the corner direction of the joint corner part of the 7th layer right coil 7; The both ends of the right coil 9 of the 6th layer left coil 5 and the 6th layer are right angle portion, the both ends part interval overlapping of the right coil 9 of the 6th layer left coil 5 and the 6th layer; The both ends of the right coil of the 5th layer left coil and the 5th layer are the joint corner part, the corner direction of the two joint corner parts at the 5th layer left coil two ends and the two joint corner parts at the 5th layer right coil two ends is opposite and leave spacing, and the corner direction of the two joint corner parts at the 5th layer left coil two ends is identical; The 4th layer, the 2nd layer the left coil and the structure of right coil are identical with the structure of the 6th layer left coil and right coil, and the 3rd layer the left coil and the structure of right coil are identical with the structure of the 5th layer left coil and right coil; The other end of the 1st layer left coil is the joint corner part, and an end of the 1st layer right coil is the joint corner part, and the joint corner part of the 1st layer left coil is opposite with the corner direction of the joint corner part of the 1st layer right coil;

The left coil of the levels of 7 layers of left coil and right coil and right coil be orientation overlapping (remove joint corner part interlaced over) mutually up and down;

The joint that the joint 8 that one end of one end of the 7th layer left coil 4 and the 6th layer right coil 9 is connected and an end of the 6th layer left coil are connected with an end of the 5th layer right coil is by the joint corner part 6 of an end of the 7th layer left coil 4, the 5th layer interlaced the opening of joint corner part of an end of right coil; The joint that the joint that the other end of the other end of the 7th layer right coil 7 and the 6th layer left coil 5 is connected is connected with the other end of the other end of the 6th layer right coil and the 5th layer left coil is by the joint corner part of the other end of the 7th layer right coil, the 5th layer interlaced the opening of joint corner part of the other end of left coil;

The joint that the joint that one end of one end of the 6th layer left coil and the 5th layer right coil is connected and an end of the 5th layer left coil are connected with an end of the 4th layer right coil is by the joint corner part of an end of the 5th layer right coil, the 5th layer interlaced the opening of joint corner part of an end of left coil; The joint that the joint that the other end of the other end of the 6th layer right coil and the 5th layer left coil is connected is connected with the other end of the other end of the 5th layer right coil and the 4th layer left coil is by the joint corner part of the other end of the 5th layer left coil, the 5th layer interlaced the opening of joint corner part of the other end of right coil;

The joint that the joint that one end of one end of the 5th layer left coil and the 4th layer right coil is connected and an end of the 4th layer left coil are connected with an end of the 3rd layer right coil is by the joint corner part of an end of the 5th layer left coil, the 3rd layer interlaced the opening of joint corner part of an end of right coil; The joint that the joint that the other end of the other end of the 5th layer right coil and the 4th layer left coil is connected is connected with the other end of the other end of the 4th layer right coil and the 3rd layer left coil is by the joint corner part of the other end of the 5th layer right coil, the 3rd layer interlaced the opening of joint corner part of the other end of left coil;

The joint that the joint that one end of one end of the 4th layer left coil and the 3rd layer right coil is connected and an end of the 3rd layer left coil are connected with an end of the 2nd layer right coil is by the joint corner part of an end of the 3rd layer right coil, the 3rd layer interlaced the opening of joint corner part of an end of left coil; The joint that the joint that the other end of the other end of the 4th layer right coil and the 3rd layer left coil is connected is connected with the other end of the other end of the 3rd layer right coil and the 2nd layer left coil is by the joint corner part of the other end of the 3rd layer left coil, the 3rd layer interlaced the opening of joint corner part of the other end of right coil;

The joint that the joint that one end of one end of the 3rd layer left coil and the 3rd layer right coil is connected and an end of the 3rd layer left coil are connected with an end of the 1st layer right coil is by the joint corner part of an end of the 3rd layer left coil, the 1st layer interlaced the opening of joint corner part of an end of right coil; The joint that the joint that the other end of the other end of the 3rd layer right coil and the 2nd layer left coil is connected is connected with the other end of the other end of the 2nd layer right coil and the 1st layer left coil is by the joint corner part of the other end of the 3rd layer right coil, the 1st layer interlaced the opening of joint corner part of the other end of left coil.

The utility model also can adopt n=5,6,8,9,10,11 or 12 etc., and its version can adopt the version of n=7, analogizes according to the version of n=7.

No matter Non-overlapping Domain Z (promptly by the interlaced position of opening of joint corner part) is placed on coil long limit, minor face or the corner of (or claiming interior electrode), all can play aforesaid effect, and Fig. 2, Fig. 3 only are preferred versions of the present utility model.

The manufacturing of chip low temperature co-fired ceramic co-mode filter following (utilizing existing LTCC Technology):

1, chooses low-temperature co-fired ceramic medium material, adopt curtain coating to make the green band.The purpose of curtain coating is that ceramic powder is changed into the green band that is easy to process.

2, the processing of green band, perforation: give birth to band and become standard size, utilize mechanical stamping, boring or laser drilling to form through hole by cutting off apparatus processing.The hole is used on the different layers with interconnection circuit.Go back communications centre molding jig hole in this stage, the aligning when helping lamination.

3, through hole is filled: modes such as thick-film printed, porous stone perfusion that conductor dbus such as silver slurry are crossed pour into give birth to in the hole of holding successfully.

4, print: adopt traditional thick film silk screen printing and computer directly to describe, conductor paste is printed and dried.Every layer printing is shown in Fig. 4-1, Fig. 4-2, Fig. 4-3, Fig. 4-4, Fig. 4-5, Fig. 4-6.

5, cutting: will finish the semi-finished product of preceding road technology, and utilize mode cutting and separating such as laser, saw, hot cutter to become single common-mode filter semi-finished product.

6, sintering: the semi-finished product inspection of single common-mode filter (substrate layer), arrangement and aligning different layers, the mating holes in making every layer are with one heart and prepare lamination; During the lamination, arrangement and the substrate layer of aiming at be in the same place by hot pressing (being generally 70 ℃, following 10 minutes of 3000psi); A step is burnt lamination altogether then: at 5 minutes～15 minutes lamination is burnt altogether to peak temperature (being generally 850 ℃), finish device main body.

7, coating electrode: relevant position coating electrode on the common-mode filter behind the sintering, the circuit of inside is drawn.

8, electroplate: behind the coating electrode process silver ink firing, but form protection layer (as nickel tin layer),, make common-mode filter can utilize the technology of Surface Mount to be applied as weld interface with plating mode word electrode surface.

The common-mode filter basic principle:

Fig. 7 (a) is the difference mode signal equivalent circuit diagram, Fig. 7 (b) is the common-mode signal equivalent circuit diagram, and Fig. 7 (a), Fig. 7 (b) are the topological structure of common-mode filter, when two paths of signals passes through two coupling coils, can produce mutual inductance M, cause the equivalent electric sensibility reciprocal of single coil to change.

When the differential mode signal passed through, mutual inductance M magnetic direction was opposite with the magnetic direction that single coil produces, and the equivalent inductance quantitative change of single coil is L-M, and inductance value reduces, and signal becomes easier to be passed through.

When common-mode signal was passed through, mutual inductance M magnetic direction was identical with the magnetic direction that single coil produces, and the equivalent inductance quantitative change of single coil is L+M, and inductance value increases, and signal becomes and is difficult for passing through.

Be transmitted as the circuit of differential mode for signal, noise signal is the common mode form.By the appropriate design loop construction, can make M approach L, produce following result:

(1) when the differential mode signal passed through, coil inductance was close to 0, and signal can pass through smoothly.

(2) when common-mode signal was passed through, coil inductance was L+M, and loss of signal increases, and has effectively suppressed noise.

The above is a preferred embodiment of the present utility model, is not limited to the utility model.Especially for the exclusive Non-overlapping Domain Z syndeton of the utility model (promptly opening), for a person skilled in the art, various forms change and change in location can be arranged by the joint corner part is interlaced.All within spirit of the present utility model and principle, any modification of being done, be equal to replacement, improvement etc., all should be included within the protection range of the present utility model.

Claims (3)

1. chip low temperature co-fired ceramic co-mode filter, it is to be stacked in by the green band that curtain coating becomes to make the LTCC body together, is printed with n layer left coil and right coil in the LTCC body, n 〉=5, the n layers, the 1st layer are respectively the pin layer; One end of the left coil of following one deck is linked to each other by joint with an end of the right coil of last layer, and the other end of the right coil of last layer is linked to each other by joint with the other end of the left coil of last layer again; It is characterized in that: the joint that the joint that an end of an end of the left coil of following one deck and the right coil of last layer is connected and an end of the left coil of last layer are connected with an end of the right coil of last layer is again opened by the joint corner part is interlaced, and the joint that the joint that the other end of the other end of the right coil of following one deck and the left coil of last layer is connected and the other end of the right coil of last layer are connected with the other end of the left coil of last layer is again opened by the joint corner part is interlaced.

2. chip low temperature co-fired ceramic co-mode filter according to claim 1 is characterized in that: it is overlapped over interlaced that described n layer left coil and right coil, the left coil of adjacent layer and right coil remove the joint corner part.

3. chip low temperature co-fired ceramic co-mode filter according to claim 1, it is characterized in that: described n layer left coil and right coil, the left coil of one deck and the both ends of right coil are right angle portion, then the both ends of left coil of another adjacent with it layer and right coil are respectively the joint corner part, the two joint corner parts at the left coil two ends of another layer are opposite with the corner direction of the two joint corner parts at right coil two ends and leave spacing, and the corner direction of the two joint corner parts at the left coil two ends of another layer is identical.

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