CN103780216A - Whole-plane EMI filter integrated structure composed of round-plane PCB coupling inductors - Google Patents

Abstract

The invention provides a whole-plane EMI filter integrated structure composed of round-plane PCB coupling inductors. The whole-plane EMI filter integrated structure comprises the round-plane PCB coupling inductors, a common mode inductor, a differential mode inductor, a differential mode capacitor I, a differential mode capacitor II, a common mode integrated LC unit I and a common mode integrated LC unit II, wherein leakage inductors of the round-plane PCB coupling inductors serve as the common mode inductor, the differential mode inductor, the differential mode capacitor I and the differential mode capacitor II respectively, one port of the differential mode capacitor I serves as the input end of a filter, and one port of the differential mode capacitor II serves as the output end of the filter. According to the whole-plane EMI filter integrated structure, the round-plane PCB coupling inductors are adopted as basic constituting units of the plane EMI filter, the coupling inductors of novel structures use a PCB as a substrate, round ceramic plane magnetic cores are embedded into the substrate, PCB printing conductive wires serve as primary and secondary windings of the magnetic cores, and the primary and secondary windings are wound around the magnetic cores through metal through holes. The coupling inductors of the novel structures omit pot-shaped magnetic cores which are large in size and sealed in the filter, decoupling of constituting modules of the filter is achieved, cooling is facilitated, the size and weight of the plane EMI filter are effectively reduced, and connection of the modules of the filter is simple.

Description

The whole plane electromagnetic interface filter integrated morphology that a kind of circular flat PCB coupling inductance forms

Technical field:

The present invention relates to a kind of whole plane magnet integrate construction of electromagnetic interface filter, particularly relate to the planar EMI filter integrated morphology that a kind of circular flat PCB coupling inductance forms.

Background technology:

Along with the continuous progress of science and technology, electronic devices and components are constantly to miniaturization, integrated development, and this makes the composition of Technics of Power Electronic Conversion device become dexterous.But because more components and parts concentrate in a little space, distribution density is too high, produces and greatly increased by the probability of electromagnetic interference.Meanwhile, be operated in the power electronic device under on off state, du/dt, di/dt are larger, and surge current and the peak voltage of its generation become interference source, make to contain in switching voltage, electric current abundant high order harmonic component.For guaranteeing the safe and reliable operation of converting means, electromagnetic interference has become must not irrespective problem in its design process.

Electromagnetic interference in field of power electronics is divided into radiated interference and conducted interference, and electromagnetic interface filter is the effective tool that suppresses conducted interference.General discrete passive component inductance and the electric capacity of adopting of electromagnetic interface filter forms, and feature is that quantity is many, volume is large, and this has hindered the trend of Technics of Power Electronic Conversion device to miniaturization, integrated development.American Electric Power electronics research center (Collaborative Psychiatric Epidemiology Surveys, CPES) propose integrated magnetic to be applied to electromagnetic interface filter, in realizing modularization and miniaturization, more effectively block EMI coupling path, become one of important directions of Development of Novel electromagnetic interface filter, this filter design method is not changing on the basis of traditional E MI filtering topology, by direct copper on high-dielectric-constant ceramics plate, form LC integrated unit, utilize respectively again the LC integrated unit of different structure to form poor common mode filtering module, and then form complete planar EMI filter.

The planar EMI filter that is applied to switch power supply system (as shown in Figure 1) of CPES design is structurally the most representative: utilize single turn lc unit to form differential mode capacitor 101, as the integrated LC structure 102 of common mode, form complete planar EMI filter with leakage inductance layer 103 and EI type magnetic core 104 at the both sides of ceramic dielectric substrate spraying plating multiturn rectangular coil coil.This structure has reduced volume, greatly improve power density, reduced the parasitic parameter of high frequency simultaneously, but the rectangle plane helical coil adopting causes conductor utilance low, inductance value is less, electric current has a greatly reduced quality the performance of filter at right angle place skewness, and ceramic substrate is easily crisp in addition, gives to install to connect and has brought very large challenge.

Nanjing Aero-Space University proposes the planar EMI filter integrated morphology (as shown in Figure 2) that a kind of circular PCB wire turn forms, this structure comprises plane kettle type magnetic core 201, differential mode capacitor I202, common mode inductance layer I203, common mode inductance layer II204, the integrated LC structure I 205 of common mode, leakage inductance layer 206, the integrated LC structure I of common mode I207, common mode inductance layer III208, common mode inductance layer IV209 and differential mode capacitor II210.With the alternative EI type magnetic core of kettle type magnetic core, helical coil is all included in magnetic core inside, conductor utilance is improved, the existence of common mode inductance layer, inductance value is increased, Planar integration LC structure adopts circular planar spiral winding, the impact that while having eliminated high frequency, rectangular coil coil corner CURRENT DISTRIBUTION inequality is brought, improve the insertion loss of filter, improve the high frequency performance of filter, but the use of kettle type magnetic core, the volume of filter is increased, do not meet the development trend of filter miniaturization, Condition and modules are enclosed in magnetic core, bring difficulty to the installation connection of each module, be unfavorable for heat radiation simultaneously, reliability while having influence on filter work.

Summary of the invention:

The object of the invention is for planar EMI filter prior art defect, proposes a kind of whole plane electromagnetic interface filter integrated morphology being made up of circular flat PCB coupling inductance, the integrated lc unit of common mode and differential mode capacitor.

The present invention adopts following technical scheme: the whole plane electromagnetic interface filter integrated morphology that a kind of circular flat PCB coupling inductance forms, it comprises the common mode inductance that circular flat PCB coupling inductance and leakage inductance thereof are served as respectively, differential mode inductance, differential mode integrated capacitance I and differential mode integrated capacitance II, the integrated lc unit I of common mode and the integrated lc unit II of common mode, described circular flat PCB coupling inductance comprises PCB substrate, be embedded into round ceramic planar magnetic core and PCB printed circuit cable on PCB substrate, wherein PCB printed circuit cable includes two, two ends of a described wherein PCB printed circuit cable are respectively E, F end, two ends of another root PCB printed circuit cable are respectively G, H end, described E, F end place PCB printed circuit cable and G, H end place PCB printed circuit cable former as round ceramic planar magnetic core respectively, secondary winding, metallic vias by PCB substrate is on magnetic core, described differential mode integrated capacitance I is identical with the structure of differential mode integrated capacitance II, it comprises the medium substrate as differential mode capacitor, on medium substrate, lower plane paving is applied the single turn helical coil of full symmetric, the end points of single turn helical coil is numbered M according to breach clockwise direction, P, N, Q, the M of described differential mode integrated capacitance I ₁and N ₁draw the input as filter by wire, the P of described differential mode integrated capacitance II ₂and Q ₂as the output of filter.

The P1 of described differential mode integrated capacitance I and Q1 connect respectively E end and the G end of circular flat PCB coupling inductance.

The integrated lc unit I of described common mode is identical with the structure of the integrated lc unit II of common mode, it comprises the medium substrate as the integrated lc unit of common mode, on the upper strata of medium substrate, lay that multiple radiuses increase successively, end to end semicircle planar spiral winding, the outermost layer of described semicircle planar spiral winding and innermost layer end points are designated as respectively A and B, ground connection after the whole copper-clads of lower floor of medium substrate, described ground plane end points is designated as C, D, the A of the integrated lc unit II of described common mode ₂and B ₂respectively with the H end of circular flat PCB coupling inductance and the N of differential mode integrated capacitance II ₂be connected, the M of described differential mode integrated capacitance II ₂b with the integrated lc unit I of common mode ₁be connected, the A of the integrated lc unit I of described common mode ₁be connected with the F end of circular flat PCB coupling inductance.

The present invention has following beneficial effect:

(1). the present invention is compared with prior art, adopt the basic composition unit of circular flat PCB coupling inductance as electromagnetic interface filter, save larger EI type magnetic core or the kettle type magnetic core of volume, realize the whole plane of filter, simultaneously differential mode integrated capacitance is that two-sided PCB take high-k is as substrate, apply the single turn helical coil of full symmetric upper plane paving, to increase differential mode capacitor value, the integrated lc unit of common mode, it is the upper strata at two-sided PCB, laying multiple radiuses increases successively, end to end semicircle planar spiral winding, copper ground connection is all applied by the lower floor of PCB,

(2). filter is being realized under equal performance condition, and volume is reduced, and power density is improved, and meets miniaturization, integrated development trend;

(3). the present invention can be applicable in the Front End Converter of distributed power supply system, is specially adapted to the area of plane to require harsh occasion;

(4). because broken the closure of magnetic core, the connection of the each module of filter becomes easily, and heat dispersion also becomes well, and this is improved filter reliability;

(5). compared with the electromagnetic interface filter forming with discrete component, volume obviously reduces, and has improved the insertion loss of filter, has improved the high frequency performance of filter.

Accompanying drawing explanation:

Fig. 1 is the integrated EMI filter based on the integrated LC structure of rectangle plane.

Fig. 2 is the integrated EMI filter based on the integrated LC structure of circular flat.

Fig. 3 A is the integrated lc unit of common mode.

Fig. 3 B is the equivalent lumped-parameter circuit of the integrated lc unit of common mode.

Fig. 4 A is circular flat PCB coupling inductance.

Fig. 4 B is the equivalent lumped-parameter circuit of circular flat PCB coupling inductance.

Fig. 5 A is differential mode integrated capacitance.

Fig. 5 B is the equivalent lumped-parameter circuit of differential mode integrated capacitance.

Fig. 6 A is the whole plane electromagnetic interface filter integrated based on circular flat PCB coupling inductance.

Fig. 6 B is the equivalent lumped-parameter circuit of whole plane integrated EMI filter.

Embodiment:

Below in conjunction with accompanying drawing, technical scheme of the present invention is elaborated:

As shown in Figure 6A, the invention provides the integrated whole plane electromagnetic interface filter of a kind of circular flat PCB coupling inductance.This structure comprises common mode inductance, the differential mode inductance that circular flat PCB coupling inductance 601 and leakage inductance thereof are served as respectively, differential mode integrated capacitance I602 and differential mode integrated capacitance II610, the integrated lc unit I605 of common mode and the integrated lc unit II607 of common mode.Wherein circular flat PCB coupling inductance 601 (as shown in Figure 4 A) comprises PCB substrate (material is FR-4), be embedded into round ceramic planar magnetic core 401 and PCB printed circuit cable 402 on PCB substrate, wherein PCB printed circuit cable 402 includes two, two ends of a described wherein PCB printed circuit cable 402 are respectively E, F end, two ends of another root PCB printed circuit cable 402 are respectively G, H end, described E, F end place PCB printed circuit cable and G, H end place PCB printed circuit cable former as round ceramic planar magnetic core respectively, secondary winding, metallic vias by PCB substrate is on magnetic core.The structure identical (as shown in Figure 5A) of differential mode integrated capacitance I602 and differential mode integrated capacitance II610, it adopts the medium substrate 502 of high dielectric constant ceramic material (material is Y5V) as differential mode capacitor, apply the single turn helical coil 501 and 503 of full symmetric the upper and lower plane paving of medium substrate 502, the end points of single-turn circular coil 501 and 503 is numbered M, P, N, Q according to breach clockwise direction, wherein the M of differential mode integrated capacitance I602 ₁and N ₁draw the input as filter by wire, its P ₁and Q ₁connect respectively E end and the G end of circular flat PCB coupling inductance 601 (as shown in Figure 4 A).The integrated lc unit I605 of common mode is identical with the structure of the integrated lc unit II607 of common mode, it adopts the medium substrate 302 of ceramic material (material is NPO) as the integrated lc unit of common mode, on the upper strata of medium substrate 302, lay that multiple radiuses increase successively, end to end semicircle planar spiral winding 301, outermost layer and the innermost layer end points of semicircle planar spiral winding 301 are designated as respectively A and B, the rear ground connection of the whole copper-clads 303 of lower floor of medium substrate 302, ground plane end points is designated as C (D), wherein the A of the integrated lc unit II607 of common mode ₂and B ₂respectively with the H of circular flat PCB coupling inductance 601 and the N of differential mode integrated capacitance II610 (as shown in Figure 5A) ₂be connected.The M of differential mode integrated capacitance II610 (as shown in Figure 5A) ₂b with the integrated lc unit I605 of common mode (as shown in Figure 3A) ₁be connected, the A of the integrated lc unit I605 of common mode (as shown in Figure 3A) ₁finally be connected with the F of circular flat PCB coupling inductance 601.The P of differential mode integrated capacitance II610 ₂and Q ₂as the output port of filter.

Fig. 3 B is the equivalent parameters circuit of Fig. 3 A, and the number of turn of the integrated lc unit upper coil of common mode is N ₁, helical coil width is w ₁, PCB substrate thickness is d ₁; See Fig. 4 A by PCB substrate and printed circuit cable thereof and the integrated circular flat PCB coupling inductance of round ceramic planar magnetic core, its former secondary number of turn is N ₂, conductor width is w ₂, winding wire turn-to-turn is divided into h, and PCB substrate thickness is d ₂, the magnetic circuit area of magnetic core is A _e, the length of magnetic path is l _e, magnetic permeability is μ _r, Fig. 4 B is its equivalent parameters circuit; As shown in Figure 5A, its number of turn is 1 to differential mode integrated capacitance, and helical coil width is w ₃, PCB substrate thickness is d ₃, equivalent parameters circuit is shown in Fig. 5 B.

The forward coupling common mode inductance in series of the integrated lc unit II of the secondary winding of circular flat PCB coupling inductance and common mode (or the former limit winding of circular flat PCB coupling inductance and the integrated lc unit I of common mode), its size is:

$L_{\mathrm{CM}}={({\mathrm{<figure-callout\; id="1"\; label="N"\; filenames="HDA0000461417670000052.png"\; state="\{\{state\}\}">N</figure-callout>}}_1+N_2)}^2\frac{{\mathrm{\&mu;}}_0{\mathrm{\&mu;}}_r{A}_e}{l_e}$

The upper and lower layer capacitance of the integrated lc unit of common mode is as common mode capacitance:

$C_{\mathrm{CM}}=\frac{{\mathrm{\&epsiv;}}_0{\mathrm{\&epsiv;}}_r{w}_1{l}_1}{{\mathrm{<figure-callout\; id="1"\; label="d"\; filenames="HDA0000461417670000052.png"\; state="\{\{state\}\}">d</figure-callout>}}_1}$

In formula, l ₁for the total length of the integrated lc unit upper coil of common mode wire.

The integrated LC structure of single turn is as differential mode capacitor:

$C_{\mathrm{DM}}=\frac{{\mathrm{\&epsiv;}}_0{\mathrm{\&epsiv;}}_r{w}_3{l}_2}{d_3}$

In formula, l ₂for the total length of the integrated LC structure coil of single turn.

The above is only the preferred embodiment of the present invention, it should be pointed out that for those skilled in the art, can also make under the premise without departing from the principles of the invention some improvement, and these improve and also should be considered as protection scope of the present invention.

Claims (3)

1. the whole plane electromagnetic interface filter integrated morphology that circular flat PCB coupling inductance forms, it is characterized in that: comprise the common mode inductance that circular flat PCB coupling inductance (601) and leakage inductance thereof are served as respectively, differential mode inductance, differential mode integrated capacitance I(602) and differential mode integrated capacitance II(610), the integrated lc unit I(605 of common mode) and the integrated lc unit II(607 of common mode), described circular flat PCB coupling inductance (601) comprises PCB substrate, be embedded into round ceramic planar magnetic core (401) and PCB printed circuit cable (402) on PCB substrate, wherein PCB printed circuit cable (402) includes two, described wherein two ends of a PCB printed circuit cable (402) are respectively E, F end, two ends of another root PCB printed circuit cable (402) are respectively G, H end, described E, F end place PCB printed circuit cable (402) and G, H end place PCB printed circuit cable (402) former as round ceramic planar magnetic core respectively, secondary winding, metallic vias by PCB substrate is on magnetic core, described differential mode integrated capacitance I(602) with differential mode integrated capacitance II(610) structure identical, it comprises the medium substrate (502) as differential mode capacitor, on medium substrate (502), lower plane paving is applied single turn helical coil (501) and (503) of full symmetric, the end points of single turn helical coil (501) and (503) is numbered M according to breach clockwise direction, P, N, Q, described differential mode integrated capacitance I(602) M ₁and N ₁draw the input as filter by wire, described differential mode integrated capacitance II(610) P ₂and Q ₂as the output of filter.

2. the whole plane electromagnetic interface filter integrated morphology that circular flat PCB coupling inductance as claimed in claim 1 forms, is characterized in that: described differential mode integrated capacitance I(602) P ₁and Q ₁connect respectively E end and the G end of circular flat PCB coupling inductance (601).

3. the whole plane electromagnetic interface filter integrated morphology that circular flat PCB coupling inductance as claimed in claim 2 forms, it is characterized in that: the integrated lc unit I(605 of described common mode) with the integrated lc unit II(607 of common mode) structure identical, it comprises as the medium substrate of the integrated lc unit of common mode (302), on the upper strata of medium substrate (302), laying multiple radiuses increases successively, end to end semicircle planar spiral winding (301), outermost layer and the innermost layer end points of described semicircle planar spiral winding (301) are designated as respectively A and B, ground connection after the whole copper-clads of lower floor (303) of medium substrate (302), described ground plane end points is designated as C, D, the integrated lc unit II(607 of described common mode) A ₂and B ₂respectively with H end and the differential mode integrated capacitance II(610 of circular flat PCB coupling inductance (601)) N ₂be connected, described differential mode integrated capacitance II(610) M ₂with the integrated lc unit I(605 of common mode) B ₁be connected, the integrated lc unit I(605 of described common mode) A ₁be connected with the F end of circular flat PCB coupling inductance (601).

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