KR101334291B1 - Emi connector filter - Google Patents

Abstract

The present invention relates to an EMI connector filter. The EMI connector filter according to one embodiment of the present invention includes a transmission line which transmits an electric signal; a soft magnetic substrate which includes a printed circuit on the surface thereof and through which the transmission line passes; and a capacitor whose one side is connected to the transmission line and whose other side is connected to the ground of the printed circuit.

Description

EMI connector filter {EMI connector filter}

The present invention relates to an EMI connector filter, and more particularly, to an EMI connector filter capable of removing noise included in an electrical signal transmitted by a transmission line, that is, an electromagnetic magnetic interference (EMI).

As the high speed and multifunctionalization of the product has recently been progressed, most electronic products use digital signals, and electromagnetic noise in the form of electromagnetic waves generated by these devices is rapidly increasing. The electromagnetic noise may affect normal control signals, communication signals, and the like of other electric devices, and accordingly, various problems such as malfunction of the electronic device and communication failure may occur.

In order to prevent a desired signal from being interfered with or disturbed by the unnecessary electromagnetic signal or electromagnetic noise, restrictions on electromagnetic noise generated from various electronic devices have been tightened. In particular, in recent years, in order to prevent interference in communication using a high frequency band such as a mobile phone, a wireless Internet, GPS, restrictions on electromagnetic noise generated by high frequency electronic devices have been strict.

Accordingly, in the related art, an electromagnetic noise is prevented from leaking out of an electronic device by using a shielding film or a shielding case made of metal and a non-metallic material, but in this case, it is insufficient to block electromagnetic noise conducted along a transmission line or a power line. There was a cotton.

An object of the present invention is to provide an EMI connector filter capable of removing noise included in an electrical signal transmitted by a transmission line.

EMI connector filter according to an embodiment of the present invention, a transmission line for transmitting an electrical signal; A soft magnetic substrate including a printed circuit on a surface thereof and through which the transmission line passes; And one end may be connected to the transmission line, the other end may include a capacitor connected to the ground of the printed circuit.

The soft magnetic substrate may have a spinel structure or a garnet structure, and may provide inductance with respect to the transmission line.

The capacitor may be a through-type capacitor in which electrodes and dielectrics are stacked in the longitudinal direction of the transmission line and penetrated by the transmission line.

Here, the capacitor, which is provided on the printed circuit, may be a multilayer ceramic capacitor (MLCC) formed by repeatedly stacking an electrode and a dielectric.

Here, further comprising a protective case for protecting the transmission line, the soft magnetic material and the capacitor from the outside, the protective case can be bonded to the soft magnetic material by a conductive polymer resin.

EMI connector filter according to an embodiment of the present invention, a transmission line for transmitting an electrical signal; A dielectric substrate including plating on a surface thereof and through which the transmission line passes; And a printed circuit on a surface thereof, and may include a soft magnetic substrate through which the transmission line passes.

Here, the dielectric substrate may be plated with an electrode having a predetermined area plated and a ground plated to provide a capacitance corresponding to the area of the electrode to the transmission line.

The dielectric substrate may be stacked on the soft magnetic substrate, the electrode may be connected to the transmission line, and the ground may be connected to the ground of the printed circuit.

Here, the transmission line includes a locking means formed in a direction perpendicular to the longitudinal direction of the transmission line, the distance by which the transmission line penetrates the soft magnetic substrate by the locking means.

Here, the soft magnetic substrate may be formed in a circular or polygonal shape.

The EMI connector filter according to an embodiment of the present invention may include an EMI filter directly to connectors connecting different electronic devices, thereby preventing electromagnetic noise from being transmitted to other electronic devices.

EMI connector filter according to an embodiment of the present invention, while being easy to manufacture with a simple configuration, it is possible to effectively attenuate the electromagnetic noise in the high frequency region.

EMI connector filter according to an embodiment of the present invention, because the soft magnetic substrate is used instead of a separate PCB substrate, it is possible to simplify the configuration of the EMI connector filter, and to reduce the size.

EMI connector filter according to an embodiment of the present invention, by bonding a soft magnetic substrate and a protective case using a conductive polymer resin, it is possible to prevent the soft magnetic substrate is broken or cracked.

The EMI connector filter according to the embodiment of the present invention includes a ferrite core inside the substrate, thereby miniaturizing the EMI connector filter.

The method of manufacturing an EMI connector filter according to an embodiment of the present invention uses a soft magnetic substrate instead of a separate PCB substrate, so that the manufacturing process may be simple and easy. In addition, since one dielectric substrate and one soft magnetic substrate may be used instead of individual capacitors or ferrite cores, the manufacturing process may be simplified and the production time may be shortened to improve productivity.

1 is a schematic diagram illustrating an EMI connector filter according to an embodiment of the present invention.
2 is a graph showing an equivalent circuit and a frequency response characteristic of an EMI connector filter according to an embodiment of the present invention.
3 is an exploded perspective view of a single-row EMI connector filter using a through-type capacitor among EMI connector filters according to an embodiment of the present invention.
4 is a plan view illustrating a printed circuit of a soft magnetic substrate included in a single-row EMI connector filter using a through-type capacitor according to an embodiment of the present invention.
FIG. 5 is an exploded perspective view of a single-row EMI connector filter using a multilayer ceramic capacitor in an EMI connector filter according to an embodiment of the present invention.
6 is a plan view illustrating a printed circuit of a soft magnetic substrate included in a single-row EMI connector filter using a multilayer ceramic capacitor according to an embodiment of the present invention.
Figure 7 is a schematic diagram showing a junction using a conductive polymer resin in the EMI connector filter according to an embodiment of the present invention.
Figure 8 is an exploded perspective view of a two-row EMI connector filter using a through-type capacitor among the EMI connector filter according to an embodiment of the present invention.
9 is an exploded perspective view of a two-row EMI connector filter using a multilayer ceramic capacitor in an EMI connector filter according to an embodiment of the present invention.
10 is an exploded perspective view of a single-row EMI connector filter using a dielectric substrate of an EMI connector filter according to an embodiment of the present invention.
11 is a plan view illustrating metal plating of a dielectric substrate included in a single-row EMI connector filter using a dielectric substrate according to an embodiment of the present invention.
12 is an exploded perspective view of a single-row EMI connector filter using a dielectric substrate and a ferrite core among EMI connector filters according to an embodiment of the present invention.
13 is a cross-sectional view of a single-row EMI connector filter using a dielectric substrate and a ferrite core among EMI connector filters in accordance with an embodiment of the present invention.
14 is an exploded perspective view and a cross-sectional view of an EMI connector filter using a ferrite core and a through-type capacitor among EMI connector filters according to an embodiment of the present invention.
15 is an exploded perspective view and a cross-sectional view of an EMI connector filter using a ferrite core and a multilayer ceramic capacitor among EMI connector filters according to an embodiment of the present invention.
16 is a cross-sectional view of a π (pie) type EMI connector filter according to an embodiment of the present invention.
17 is a sectional view and a perspective view showing a transmission line of an EMI connector filter according to an embodiment of the present invention.
18 is a flowchart illustrating a method of manufacturing an EMI connector filter according to an embodiment of the present invention.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. In the following detailed description of the preferred embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear. In the drawings, like reference numerals are used throughout the drawings.

In addition, in the entire specification, when a part is referred to as being 'connected' to another part, it may be referred to as 'indirectly connected' not only with 'directly connected' . Also, to "include" an element means that it may include other elements, rather than excluding other elements, unless specifically stated otherwise.

1 is a schematic diagram illustrating an EMI connector filter according to an embodiment of the present invention, and FIG. 2 is a graph showing an equivalent circuit and a frequency response characteristic of an EMI connector filter according to an embodiment of the present invention.

Hereinafter, a function of an EMI connector filter according to an embodiment of the present invention will be described with reference to FIGS. 1 and 2.

Referring to FIG. 1A, when the input signal sig_in is input to the input terminal a of the transmission line 10, the output signal sig_out is transmitted to the output terminal b. The transmission line 10 transmits an electrical signal, and may include any means for transmitting an electrical signal in general, including a wave gurad.

In the case where the transmission line 10 is ideal, a signal having the same waveform as the input signal sig_in is output from the output terminal b to sig_out, but the waveform of the distorted form is actually represented as the output signal sig_out due to noise. In particular, as shown in FIG. 1A, a large amount of noise of a high frequency component may be included. As described above, the interference of reception of a desired input signal by an unnecessary electromagnetic signal or electromagnetic noise is called an electromagnetic interference, that is, EMI (Electro Magnetic Interference). The EMI may include radiated EMI that radiates directly from electrical and electronic devices, conductive EMI that leaks along a power line, and the like.

Therefore, in order to reduce the signal distortion of the input signal by the EMI and to transmit the input signal of the correct form, as shown in Figure 1 (b), including the EMI connector filter 100 on the transmission line (10) can do. The EMI connector filter 100 may be a low pass filter (LPF), and specifically, may be implemented as a T (tee) type LC filter or a π (pie) type LC filter shown in FIG. Can be. In the case where only one inductor is provided in the T-type LC filter, the L-type LC filter may be used.

The T-type LC filter and the Π-type LC filter shown in FIG. 2 (a) may have frequency response characteristics as shown in FIG. 2 (b) as a low pass filter. That is, the frequency above the cutoff frequency fc may be blocked, and only the frequency below the cutoff frequency fc may be passed. Therefore, if the appropriate cutoff frequency fc is set by adjusting the inductances Lx, Lx 'and capacitances C, C1, and C2 of the EMI connector filter 100, noise of unnecessary high frequency components is cut off and input of low frequency components is performed. The signal sig_in can be output to the output terminal b. However, a specific method for implementing the EMI connector filter 100 may be various, and will be described below with reference to the EMI connector filter 100 according to an embodiment of the present invention.

3 is an exploded perspective view of a single-row EMI connector filter using a through-type capacitor among EMI connector filters according to an embodiment of the present invention.

Referring to FIG. 3, a single-row EMI connector filter using a through capacitor according to an embodiment of the present invention may include a transmission line 10, a soft magnetic substrate 20 a, and a through capacitor 30 a. In addition, the protective case 40 may be further provided.

Hereinafter, an EMI connector filter according to an embodiment of the present invention will be described with reference to FIG. 3.

The transmission line 10 may sequentially pass through the through capacitor 30a and the soft magnetic substrate 20a. Here, the soft magnetic substrate 20a may include a printed circuit on a surface thereof, and the printed circuit may vary according to the type of the EMI connector filter. One end of the through capacitor 30a may be connected to the transmission line 10, and the other end thereof may be connected to the ground included in the printed circuit of the soft magnetic substrate 20a.

Since the soft magnetic substrate 20a performs a function of providing inductance to the transmission line 10 penetrating the soft magnetic substrate 20a, the EMI connector filter may include the transmission line 10. Has a line inductance Lx and an inductance Lf by the soft magnetic substrate 20a. In addition, it may have a capacitance (C) by the through-type capacitor (30a) located between the transmission line 10 and the ground. Therefore, the EMI connector filter is equivalent to the T-type LC filter shown in FIG. 1 (b) and can function as a low pass filter.

Since the electrical signal input to the transmission line 10 is transmitted along the transmission line 10, the electrical signal may sequentially pass through the through-type capacitor 30a and the soft magnetic substrate 20a. As described above, since the through-type capacitor 30a and the soft magnetic substrate 20a operate as a low pass filter, the electrical signal input to the transmission line 10 is filtered to remove noise of high frequency components and to remove low frequency components. Only may be output from the transmission line (10). Here, the cutoff frequency of the low pass filter may be determined by the capacitance of the through capacitor 30a and the inductance of the soft magnetic substrate 20a. Therefore, the capacitance of the through-type capacitor 30a and the inductance by the soft magnetic substrate 20a may be set differently according to the frequency band of the high frequency noise to be removed through the EMI connector filter. The capacitance and inductance may be determined according to the physical structure of the through-type capacitor 30a and the soft magnetic substrate 20a or the kind of material constituting the through-type capacitor 30a and the soft magnetic substrate 20a.

Referring to FIG. 3, the EMI connector filter utilizes the soft magnetic substrate 20a instead of a PCB substrate made of a phenol resin or an epoxy resin. Therefore, the EMI connector filter can omit the configuration of the PCB board, and it is not necessary to further include a separate configuration for providing inductance to the EMI connector filter. That is, using the soft magnetic substrate 20a can simplify the configuration of the EMI connector filter and minimize the space for providing inductance to the EMI connector filter. Therefore, the EMI connector filter can be miniaturized, and the EMI connector filter can be produced more easily.

Looking at each configuration constituting the EMI connector filter in more detail, the transmission line 10 may perform a function of transmitting an electrical signal input from one end to the other end. However, as described above, the electrical signal transmitted along the transmission line 10 may be added to the noise component of the high frequency by EMI, the level of the electrical signal by the resistance of the transmission line 10 itself. May be attenuated. Accordingly, the EMI connector filter is used to remove high frequency noise components included in the electrical signal, and the transmission line 10 is formed of a metal having high electrical conductivity, thereby attenuating the electrical signal level by the transmission line 10. Can be reduced. In general, the transmission line 10 may have a pin shape of a cylindrical elongated metal conductor, and a metal having high electrical conductivity may be plated on the surface of the pin to increase conductivity. Here, the transmission line 10 may further include a locking means as shown in FIG. Description of the transmission line 10 and the locking means will be described later with reference to FIG.

The soft magnetic substrate 20a may pass through the transmission line 10 and may include an insertion groove through which the transmission line 10 passes. The soft magnetic substrate 20a is configured to provide an inductance to the transmission line 10, and the size of the inductance provided by the soft magnetic substrate 20a is the soft magnetic substrate surrounding the transmission line 10. The thickness of 20a and the type of soft ferrite constituting the soft magnetic substrate 20a may vary. Specifically, the soft magnetic substrate 20a may be formed of a soft magnetic material having a spinel structure or a garnet structure. That is, Mn-Zn ferrite, Ni-Zn ferrite, YIG ferrite, etc. may be used as the soft magnetic substrate 20a. In particular, the Mn-Zn ferrite and Ni-Zn ferrite may be in the range of tens to hundreds of ohms in the high frequency region. While having an impedance, direct current resistance is very small. Therefore, the Mn-Zn ferrite or Ni-Zn ferrite may be selected to reduce high frequency noise with respect to an input signal of 1 Ghz or more.

In addition, referring to FIG. 3, the through-type capacitor 30a may be positioned on an insertion groove of the soft magnetic substrate 20a, and the soft magnetic substrate 20a may be formed with respect to the through-type capacitor 30a. Grounding may be provided. Here, the ground is formed by a printed circuit formed on the surface of the soft magnetic substrate 20a. The printed circuit of the soft magnetic substrate 20a will be described with reference to FIG.

In the printed circuit of the soft magnetic substrate 20a, a conductor such as a metal is plated on the surface of the soft magnetic body 20 having an insertion groove as shown in FIG. 4 (a) according to the pattern shown in FIG. Can be formed in a manner. 4B illustrates the front, side, and rear surfaces of the printed circuit printed on the surface of the soft magnetic substrate 20a in that order.

Looking at the front surface of the soft magnetic substrate 20a, the conductor may be plated as a whole except for the periphery of the insertion groove through which the transmission line 10 passes. The plating is to form a ground plane on the surface of the soft magnetic substrate 20a, the plated conductor is then electrically connected to the protective case 40, as shown in Figure 3 to form a ground plane can do. In this case, when the transmission line 10 comes into contact with the ground plane, the electrical signal transmitted through the transmission line 10 may be lost or deformed, and thus the plating of the transmission line 10 is omitted except for plating around the insertion groove. ) Can be prevented from contacting the ground. Sides of the soft magnetic substrate 20a may be plated with conductors to electrically connect the front and rear surfaces, and may contact the protective case 40 through the rear surfaces. Therefore, the rear surface may include plating for electrically connecting with the protective case 40, and like the front surface, the conductor may not be plated about the periphery of the insertion groove. The metal to be plated on the surface of the soft magnetic substrate 20a may be silver (Ag) or tin (Zn).

Here, although FIG. 3 illustrates that the soft magnetic substrate 20a has a rectangular shape, the soft magnetic substrate 20a is not limited thereto and may be configured in various forms such as a circle or a trapezoid. In addition, the position of the transmission line 10 may vary depending on the shape of the soft magnetic substrate 20a.

The through capacitor 30a is formed by stacking electrodes 31, 31 ′ and a dielectric 32 in the longitudinal direction of the transmission line 10, wherein the transmission line 10 is a central portion of the through capacitor 30a. Can penetrate through One electrode 31 of the through capacitor 30a may be connected to the transmission line 10, and the other electrode 31 ′ may be connected to the ground of the soft magnetic substrate 20a. Therefore, the through capacitor 30a may provide a capacitance between the transmission line 10 and the ground. That is, the through capacitor 30 corresponds to the capacitor C which is branched from the T-type LC filter of FIG. 2 (a) and connected to ground.

The capacitance of the through capacitor 30a can be calculated using. Is the dielectric constant of the dielectric 32, A is the cross-sectional area of the through capacitor 30a, and d is the thickness of the through capacitor 30a. Therefore, the capacitance can be set by adjusting the type of dielectric 32 constituting the through capacitor 30a, the cross sectional area and the thickness of the through capacitor 30a. However, the cross-sectional area and the length of the thickness of the through capacitor 30a may be limited according to the size required for the EMI connector filter.

In particular, the distance between the transmission line 10 may be predetermined in advance by the standard, etc., the size of the cross-sectional area of the through-type capacitor 30a may be limited. In addition, as the thickness of the dielectric 32 increases, the size of the EMI connector filter also increases, so that the thickness of the dielectric 32 may be limited in order to reduce the size of the EMI connector filter.

Therefore, the thickness and cross-sectional area of the dielectric 32 are set in a limited range, and the capacitance of the through-type capacitor 30a may be mainly determined by the dielectric constant of the dielectric 32. The dielectric 32 may be formed of various materials such as plastic film, ceramic, tantalum, electrolytic material, paper, and BST (Ba _x Sr _{1 - x} TiO ₃ ) thin film or MCT (Hg _{1 - x} Cd _x Te) thin film. You can also use series. The dielectric constant of the dielectric 32 may vary from 5 to 500,000 depending on the type, and the dielectric 32 may be selected according to the capacitance value required for the through capacitor 30a. However, the capacitance of the through capacitor 30a is not limited in the range of 5 to 500,000, and it is also possible to select a dielectric 32 having a dielectric constant outside the range as necessary.

Additionally, the EMI connector filter may further include a protective case 40 to protect the transmission line 10, the soft magnetic substrate 20a, and the through-type capacitor 30a from the outside. The protective case 40 may be formed of metal, and the protective case 40 may be provided in a form of surrounding the soft magnetic substrate 20a and the through capacitor 30a on the front and rear surfaces thereof. Accordingly, since external force or foreign matter is blocked by the protective case 40, the soft magnetic substrate 20a and the through capacitor 30a may be protected. In addition, since the protective case 40 may be electrically connected to the soft magnetic substrate 20a, it is also possible to provide a ground plane for the soft magnetic substrate 20a.

Referring to FIG. 7, a conductive polymer resin (P) may be used to connect the soft magnetic substrate 20a and the protective case 40. That is, in place of soldering (Pb-Soldering / Pb Free Soldering) generally used to connect the PCB substrate and the protective case 40, the soft magnetic substrate (20a) and the protective case using a conductive polymer resin (P) 40 can be joined.

Conventionally, the PCB substrate and the protective case are adhered by soldering or the like, but the soft magnetic substrate 20a is inferior in elasticity to the PCB substrate formed of the petrol resin or the epoxy resin. The soft magnetic substrate 20a has a high risk of breaking or cracking. Therefore, the flexible magnetic substrate 20a may be cracked or cracked by bonding with a flexible conductive polymer resin P instead of soldering. In addition, in order to electrically connect between the soft magnetic substrate 20a and the protective case 40, a metal component such as silver (Ag), copper (Cu), or an amorphous carbon such as conductive carbon (C) material or glass A material obtained by plating a conductive material on a material may be included in the conductive polymer resin (P). In general, the polymer resin may not have electrical conductivity. However, as described above, in order to form the ground plane on the soft magnetic substrate 20a, the polymer resin needs to be electrically connected to the protective case 40. Polymer resin can be utilized.

After connecting the protective case 40 and the soft magnetic substrate 20a using the conductive polymer resin, non-conductive properties such as liquid crystal polymer (LCP) and polyvinyl chloride (PVC) are used. By using a polymer resin having a, it may be sealed and fixed between the soft magnetic substrate 20a and the protective case 40.

In addition, although FIG. 3 illustrates a single-row EMI connector filter, the EMI connector filter may include two or more rows of transmission lines 10 depending on the type. That is, as shown in Fig. 8, the transmission lines can be arranged in two columns.

The number of the transmission line 10, that is, the number of pins may vary depending on the product in which the EMI connector filter is used, and generally 9 pins (game connector, USB connector), 15 pins (consisting of two columns) There may be EMI connectors such as R232 DATA), 45 pin (HDD), 37 pin (FDD, Card Reader).

Accordingly, the number of transmission lines 10, the number of through-type capacitors 30a, and the number of insertion grooves included in the soft magnetic substrate 20c may be extended according to the type of product in which the EMI connector filter is used. EMI connector filters having pins in one, two, or more than two rows can be provided.

In addition, although FIG. 8 illustrates that the soft magnetic substrate 20c is a trapezoid, the present invention is not limited thereto and may be configured in various forms such as a circle or a rectangle. In addition, the position of the transmission line 10 may vary according to the shape of the soft magnetic substrate 20c.

FIG. 5 is an exploded perspective view of a single-row EMI connector filter using a multilayer ceramic capacitor (MLCC) among EMI connector filters according to an exemplary embodiment of the present invention.

Referring to FIG. 5, a single-row EMI connector filter using a multilayer ceramic capacitor according to an embodiment of the present invention may include a transmission line 10, a soft magnetic substrate 20b, and a multilayer ceramic capacitor 30b. have.

Hereinafter, an EMI connector filter according to an embodiment of the present invention will be described with reference to FIG. 5.

As shown in FIG. 5, the transmission line 10 may pass through an insertion groove formed in the soft magnetic substrate 20b, and the multilayer ceramic capacitor 30b may be provided on the soft magnetic substrate 20b. . The multilayer ceramic capacitor 30b may be provided in the form of a chip capacitor on the soft magnetic substrate 20b to provide capacitance to the EMI connector filter.

One end of the multilayer ceramic capacitor 30b may be electrically connected to the transmission line 10 through the soft magnetic substrate 20b, and the other end may be connected to the ground provided in the soft magnetic substrate 20b. Accordingly, the multilayer ceramic capacitor 30b may operate as a capacitor branched from the transmission line 10 and connected to ground, similarly to the through capacitor 30a of FIG. 3.

In particular, since the multilayer ceramic capacitor 30b is implemented as a chip capacitor on the soft magnetic substrate 20b, the multilayer ceramic capacitor 30b may operate normally even in a high frequency band of 1 Ghz or more when compared with other electrolytic capacitors or plastic film type capacitors. Therefore, the present invention can be applied even when an input signal of high frequency is input. In addition, compared to the through capacitor 30a, since the volume occupies is relatively small, it may be more advantageous to implement a small EMI connector filter. Here, the dielectric used in the multilayer ceramic capacitor 30b may be various, such as BST (Ba _x Sr _{1 - x} TiO ₃ ) thin film or MCT (Hg _{1 - x} Cd _x Te) thin film series. Depending on the dielectric constant can vary from 5 to 500,000.

Here, the connection between the multilayer ceramic capacitor 30b, the transmission line, and the ground is by a printed circuit formed on the surface of the soft magnetic substrate 20b, and the printed circuit of the soft magnetic substrate 20b is shown in FIG. It demonstrates with reference to.

The printed circuit of the soft magnetic substrate 20b is a method of plating a conductor such as a metal on the surface of the soft magnetic body 20 having an insertion groove as shown in FIG. 6 (a) according to the pattern shown in FIG. It can be formed as. 6 (b) shows the front, side, and rear surfaces of the printed circuit printed on the surface of the soft magnetic substrate 20a in that order.

Looking at the front surface of the soft magnetic substrate 20b, the first region is connected to the insertion groove and plated with a conductor, a third region with the conductor plated to form a ground plane, and an unplated region. It can be distinguished by the 2nd area | region which separates 2 area | regions. One end of the multilayer ceramic capacitor 30b may be connected to the transmission line 10 by joining the first region, and the other end may be connected to ground by joining the third region. As described above, the second region exists to prevent contact between the transmission line 10 and the ground plane, and the front and rear surfaces may be electrically connected by the side of the plated soft magnetic substrate 20b. have. Thereafter, since the rear surface contacts the protective case 40, a ground surface may be provided on the surface of the soft magnetic substrate 20b.

In addition, although FIG. 5 illustrates a single row EMI connector filter, the EMI connector filter may include two or more rows of transmission lines 10 depending on the type. That is, as shown in Fig. 9, the transmission lines can be arranged in two columns.

The number of the transmission line 10, that is, the number of pins may vary depending on the product in which the EMI connector filter is used. Generally, 9 pins (game connector) and 15 pins (VGA connector) are configured in one row. There may be a 25-pin (for R232 DATA) EMI connector, or two-row EMI connectors such as 45-pin (HDD) and 37-pin (FDD).

Accordingly, the number of transmission lines 10, the number of multilayer ceramic capacitors 30b, and the number of insertion grooves included in the soft magnetic substrate 20d may be extended according to the type of product in which the EMI connector filter is used. It is possible to provide an EMI connector filter having pins in one, two or more rows.

As described above, the soft magnetic substrates 20b and 20d of FIGS. 5 and 9 are illustrated in the form of rectangles and trapezoids, but the soft magnetic substrates 20b and 20d are not limited thereto and may be various shapes such as a circle or a polygon. It can be configured as. In addition, the position of the transmission line 10 may also vary depending on the shape of the soft magnetic substrates 20b and 20d.

10 is an exploded perspective view of a single-row EMI connector filter using a dielectric substrate of an EMI connector filter according to an embodiment of the present invention.

Referring to FIG. 10, a single-row EMI connector filter using a dielectric substrate according to an embodiment of the present invention may include a transmission line 10, a dielectric substrate 30c, and a soft magnetic substrate 20e.

Hereinafter, an EMI connector filter according to an embodiment of the present invention will be described with reference to FIG.

As shown in FIG. 10, in this embodiment, no individual capacitor is provided for each transmission line, and instead, one dielectric substrate 30c may be used to provide capacitance. That is, after forming a plurality of electrodes on the front and rear surfaces of one dielectric substrate 30c made of a dielectric through plating, the capacitance formed between the front and rear electrodes is converted into a capacitor ( C) can be used.

Here, the magnitude of the capacitance can be calculated using the bar as previously described. Is the dielectric constant, A is the cross-sectional area of the electrode formed on the dielectric substrate 30c, and d is the thickness of the dielectric substrate 30c. Since the dielectric constant and thickness of the dielectric substrate 30c are difficult to change after the dielectric substrate 30c is selected, the capacitance can be adjusted by adjusting the cross-sectional area of the electrode to be formed. The electrode formed on the dielectric substrate 30c may be formed by printing by a printing technique, similar to the soft magnetic substrates 20a and 20b described above. In this case, as compared with the case of using the through-type capacitor 30a or the multilayer ceramic capacitor 30b, it is possible to simply provide the capacitance, thereby significantly reducing the time and cost required for the production of the EMI connector filter. .

In the EMI connector filter, as shown in FIG. 10, the soft magnetic substrate 20e is stacked together with the dielectric substrate 30c, and thus the inductance by the soft magnetic substrate 20e may be provided. In particular, the soft magnetic substrate 20e may include a printed circuit, and a ground plane may be formed on the printed circuit. Accordingly, the dielectric substrate connected to the ground plane may provide a capacitance corresponding to the area of the electrode, and the soft magnetic substrate 20e may provide a corresponding inductance. That is, the EMI connector filter shown in FIG. 10 may provide a circuit equivalent to the T-type LC filter of FIG.

Specifically, a printed circuit for the surfaces of the dielectric substrate 30c and the soft magnetic substrate 20e may be formed as shown in FIG. Here, FIG. 11 (a) shows the dielectric material 30 before plating on the surface, and FIG. 11 (b) shows that the dielectric substrate 30c is formed by plating on the surface of the dielectric material. To indicate. Here, FIG. 11 (b) shows the front, side, and back of the dielectric substrate 30c in that order, and FIG. 11 (c) shows the side, front, and back of the soft magnetic substrate 20e.

Referring to FIG. 11B, an electrode having a predetermined area around an insertion groove is formed on a front surface of the dielectric 30 having an insertion groove formed therein, and a soft magnetic substrate 20e on a rear surface thereof. It is possible to form an electrode that can be in contact with the ground plane. As shown in FIG. 11B, since the electrodes formed on the front surface and the electrodes formed on the rear surface are not electrically connected, capacitances corresponding to the sizes of the electrodes formed on the front surface may be provided.

Referring to FIG. 11C, the printed circuit of the soft magnetic substrate 20e may include plating on the soft magnetic substrate 20e as a whole to provide grounding. However, in order to prevent the transmission line 10 from coming into contact with the rear surface of the dielectric substrate 30c, plating may not be performed around the insertion groove.

10 to 11 illustrate that the dielectric substrate 30 and the soft magnetic substrate 20e have a rectangular shape, but are not limited thereto and may be configured in various forms such as a circle or a trapezoid.

12, a ferrite core 20f may be used instead of the soft magnetic substrate 20e. That is, instead of the soft magnetic substrate 20e, the ferrite core 20f may provide inductance to each transmission line 10.

The ferrite core 20f may be formed of a soft magnetic material having a spinel structure or a garnet structure, and is generally formed in a cylindrical shape so that a center thereof may be penetrated by the transmission line 10. Accordingly, inductance may be provided to the transmission line 10 that passes through the transmission line 10. The ferrite core 20f is a kind of soft magnetic material, and any type other than the ferrite core 20f may be used as long as it is a soft magnetic material capable of providing inductance to the transmission line 10.

However, in the case of FIG. 12, since the ground needs to be provided to the rear surface of the dielectric substrate 30c, as shown in FIG. 13, the dielectric substrate 30c and the protective case 40 may be disposed on the conductive polymer. It can be bonded by resin (P). As described above, in addition to the conductive polymer resin (P), it is also possible to connect by soldering, or may further include a separate PCB substrate for providing grounding.

Figure 14 (a) is an exploded perspective view of an EMI connector filter using a ferrite core and a through capacitor among EMI connector filters according to an embodiment of the present invention, Figure 14 (b) is a cross-sectional view of the EMI connector filter.

Referring to FIGS. 14A and 14B, an EMI connector filter using a ferrite core and a through capacitor according to an embodiment of the present invention includes a transmission line 10, a PCB board 50, and a penetration line. It may include a type capacitor 30a and a ferrite core 20f.

Hereinafter, an EMI connector filter according to an embodiment of the present invention will be described with reference to FIGS. 14A and 14B.

The transmission line 10 may sequentially pass through the through capacitor 30a, the ferrite core 20f, and the PCB substrate 50. Here, the ferrite core 20f is located inside the insertion groove 1 of the PCB substrate 50, and one electrode 31 of the through capacitor 30a is joined to the transmission line 10 and the other. The electrode 31 ′ may be bonded to the PCB substrate 50. In this case, the PCB substrate 50 may provide ground to the other electrode 31 ′ of the through-type capacitor 30a.

The ferrite core 20f may perform a function of providing inductance to the transmission line 10. Therefore, the EMI connector filter has a line inductance Lx of the transmission line 10 and an inductance Lf by the ferrite core 20f, and is a through type connected between the transmission line 10 and the ground. It may have a capacitance (C) by the capacitor (30a). Therefore, the EMI connector filter is equivalent to the T-type LC filter shown in FIG. 1 (b) and can function as a low pass filter.

Accordingly, the capacitance of the through-type capacitor 30a and the inductance by the ferrite core 20f may be set differently according to the frequency band of the high frequency noise to be removed through the EMI connector filter. The capacitance and inductance may be determined according to the physical structure of the through capacitor 30a and the ferrite core 20f or the type of material constituting the through capacitor 30a and the ferrite core 20f.

Here, the ferrite core 20f has a feature provided in the insertion groove 1 of the PCB substrate 50, as shown in FIGS. 14 (a) and 14 (b). Therefore, the EMI connector filter does not need a separate space for providing the ferrite core 20f, it is possible to minimize the space for providing inductance to the EMI connector filter. Accordingly, the EMI connector filter can be miniaturized, and inductance can be easily provided to the transmission line 10.

Looking at each of the components constituting the EMI connector filter in more detail, the PCB substrate 50 is to pass through the transmission line 10, the transmission line 10 is provided with an insertion groove (1) through which to pass. Can be. Specifically, the through-type capacitor 30a may be located on the insertion groove 1 of the PCB board 50, the PCB board 50, the through-type contact with the PCB board 50. Grounding may be provided to the other end 31 'of the capacitor 30a. In addition, the ferrite core 20f may be provided inside the insertion groove 1 of the PCB substrate 50. Here, the PCB substrate 50 may be formed of an epoxy resin or a phenol resin generally used.

The ferrite core 20f is provided in an area where the transmission line 10 penetrates the PCB board 50. Specifically, the ferrite core 20f may be located in the insertion groove 1 of the PCB board 50. . As described above, the ferrite core 20f provides an inductance with respect to the transmission line 10, and the size of the inductance is the length of the ferrite core 20f surrounding the transmission line 10 and the ferrite core ( It may vary depending on the type of 20f). Here, as shown in Figure 13 (b), the ferrite core (20f) is provided in the insertion groove (1) of the PCB substrate 50, so that a separate space for providing the ferrite core (20f) It is not necessary. Therefore, the size of the EMI connector filter can be significantly reduced, and the inductance can be easily provided to the transmission line 10.

In addition, since the transmission line 10 and the through capacitor 30a have been described above, a detailed description thereof will be omitted.

Figure 15 (a) is an exploded perspective view of an EMI connector filter using a ferrite core and a laminated ceramic capacitor in the EMI connector filter according to an embodiment of the present invention, Figure 15 (b) is a cross-sectional view of the EMI connector filter.

Hereinafter, an EMI connector filter according to an embodiment of the present invention will be described with reference to FIGS. 15A and 15B.

According to an embodiment of the present invention, the transmission line 10 may sequentially pass through the ferrite core 20f and the PCB substrate 50, and the ferrite core 20f is an insertion groove of the PCB substrate 50. (1) It can be located inside. Here, the multilayer ceramic capacitor 30b may be provided on the PCB substrate 50. The multilayer ceramic capacitor 30b may be provided on the PCB substrate 50 in the form of a chip capacitor to provide capacitance to the EMI connector filter.

In addition, according to another exemplary embodiment of the present invention, a single layer ceramic capacitor may be used instead of the multilayer ceramic capacitor 30b. The multilayer ceramic capacitor 30b is already commercially available and may optionally include a multilayer ceramic capacitor 30b having a specific capacitance as needed. However, since electrical signals used in electronic devices and the like progress gradually at high frequencies due to digitalization of electronic devices, it is necessary to utilize capacitors having precise capacitance even at high frequencies for accurate filtering. Therefore, the capacitor may be provided in such a manner that a single layer ceramic capacitor is formed on the PCB 50 in the process of generating the PCB 50.

That is, after designing the dielectric and electrode size and thickness of the capacitor according to the desired capacitance, it may be implemented in the form of a chip capacitor on the PCB substrate 50. In the case of the multilayer ceramic capacitor 30b, the capacitor is implemented by repeatedly stacking a ceramic that functions as a capacitor electrode and a dielectric. However, the capacitor may be implemented by configuring the capacitor electrode and the dielectric in a single layer. In this case, the capacitor can be kept constant even at a high frequency of 1Ghz or higher, and the capacitance of the capacitor can be selected precisely to have a desired capacitor.

16 is a cross-sectional view of a Π-type EMI connector filter according to an embodiment of the present invention. Hereinafter, a π-type EMI connector filter according to an embodiment of the present invention will be described with reference to FIG.

Referring to FIG. 16, the Π-type EMI connector filter according to the embodiment of the present invention may have the same structure as the two T-type EMI connector filters of FIG. 14 pasted together.

Here, the line inductance of the transmission line 10 on the input side, the composite inductance of the first ferrite core (top, 20f) and the second ferrite core (bottom, 20f), and the line of the transmission line 10 on the output side The inductance component of the Π-type filter can be configured by the inductance, and the parallel capacitance component of the Π-type filter can be configured by the first through-type capacitor (top, 30a) and the second through-type capacitor (lower, 30a). have. Therefore, the configuration shown in Fig. 16 can constitute a circuit equivalent to the? LC filter of Fig. 2A.

Here, the first PCB substrate (top, 50) and the second PCB substrate (bottom, 50) may be in contact with each other, the first ferrite core (top, 20f) and the second ferrite core (bottom, 20f) is connected It may also consist of one ferrite core.

In addition, FIG. 16 illustrates an embodiment in which a pi-type EMI connector filter is configured by using an EMI connector filter using a ferrite core and a through-type capacitor of FIG. 14, but using the multilayer ceramic capacitor instead of the through-type capacitor. It is also possible to construct a type EMI connector filter. That is, the Π-type EMI connector filter may be configured by attaching two T-type EMI connector filters using the multilayer ceramic capacitor of FIG. 15 to each other. Furthermore, it is also possible to configure the Π-type EMI connector filter by using one T-type EMI connector filter using a through-type capacitor and another T-type EMI connector filter using a laminated ceramic capacitor.

Here, in the case of using the Π-type connector filter instead of the T-type EMI connector filter, the frequency response characteristic curve of the low pass filter may be better than in the case of using the T-type EMI connector filter. That is, in the case of using the? -Type connector filter, compared with the case of using the T-type connector filter, the frequency less than the cutoff frequency is hardly attenuated, and the frequency more than the cutoff frequency can be attenuated more quickly and surely.

In addition, although not shown, the ferrite core 20f provided in the PCB substrate 50 is thicker than the thickness of the PCB substrate 50 or a separate ferrite core 20f is provided in the transmission line 10. In addition, it may provide a higher inductance to the EMI connector filter. In this case, since the volume of the EMI connector filter may be larger, it is preferable to apply the multilayer ceramic capacitor rather than the through-type capacitor.

In addition, the transmission line 10 of the EMI connector filter according to an embodiment of the present invention can be implemented as shown in FIG. That is, the transmission line 10 may include a locking means formed in a direction perpendicular to the longitudinal direction of the transmission line 10, the transmission line 10 is the substrate by the contact with the locking means The distance through it can be limited. The substrate may be any one of the soft magnetic substrate 20, the dielectric substrate 30c, and the PCB substrate 50.

Specifically, the locking means is formed to be larger than the radius of the insertion groove 1 provided in the substrate so that the locking means is caught on the substrate, or a through-type capacitor 30a contacting the locking means is placed on the substrate. You can get caught. Therefore, the transmission line 10 can be prevented from being separated from the substrate, and the height of the transmission line 10 can be kept constant according to the height of the locking means. That is, using the transmission line 10 including the locking means may facilitate assembly of the EMI connector filter, which may lead to an improvement in productivity.

In addition, the area where the transmission line 10 is in contact with the substrate or the through-type capacitor 30a is increased by the locking means, so that the transmission line 10 and the substrate or the through-type capacitor 30a are increased. The solderability between them can be improved.

In FIG. 17, the locking means is illustrated in the form of a disc, but is not limited thereto. The locking means may have various shapes such as a triangle, a square, a circle, a cylinder, and a cone. In other words, any shape may be used as long as the transmission line 10 does not get caught by the substrate. Furthermore, after the groove is provided in the transmission line 10 so that the through-type capacitor 30a can be caught, the through-type capacitor 30a is fixed in the groove, and the through-type capacitor 30a is caught by the catching means. It can also be used as. In addition, the transmission line 10 may be formed in a cylindrical shape as shown in FIG. 17, and may have various types of cross sections including a rectangle or a square in addition to the cylindrical shape.

18 is a flowchart illustrating a method of manufacturing an EMI connector filter according to an embodiment of the present invention.

Referring to FIG. 18, a method of manufacturing an EMI connector filter according to an exemplary embodiment of the present invention may include a circuit printing step S10 and a capacitor connecting step S20, and after the capacitor connecting step S20. In addition, it may further include a bonding step (S30).

18, a method of manufacturing an EMI connector filter according to an embodiment of the present invention will be described.

In the circuit printing step (S10), a circuit pattern may be printed on the surface of the soft magnetic substrate on the soft magnetic substrate through which the transmission line passes. In the circuit printing step (S10), first, an insertion groove through which the transmission line passes through the soft magnetic material may be formed, and then the circuit pattern may be printed. The circuit pattern is for forming ground on the surface of the soft magnetic substrate, and may be plated with a conductor as a whole except for the periphery of the insertion groove. Specifically, the soft magnetic substrate may be printed in a pattern as shown in FIG. 4 (b) or FIG. 5 (b). Here, the part indicated by the diagonal line is a part plated with a conductor. The printing pattern for the soft magnetic substrate may vary depending on the type of EMI connector filter and may vary according to the type of capacitor used.

In the capacitor connecting step (S20), the ground on the circuit pattern and one electrode of the capacitor may be connected, and the transmission line may be connected to the other electrode of the capacitor.

In the case of the through capacitor, the through line capacitor and the soft magnetic substrate may be sequentially penetrated using the transmission line, and may be coupled by soldering the electrodes of the through capacitor. In the case of a multilayer ceramic capacitor, the multilayer ceramic capacitor may be positioned according to a circuit pattern on the soft magnetic substrate, the soft magnetic substrate may be penetrated through the transmission line, and then the transmission line and the soft magnetic substrate may be connected. In the case of the multilayer ceramic capacitor, one end of the multilayer ceramic capacitor may be connected to a transmission line, and the other end of the multilayer ceramic capacitor may be connected to the ground according to the circuit pattern.

In addition, the method of manufacturing the EMI connector filter may further include a bonding step S30, wherein the bonding step S30 is provided between a protective case protecting the EMI connector filter from the outside and the ground of the soft magnetic substrate. It can be bonded with a conductive polymer resin. A ground plane may be formed on the soft magnetic substrate, and the conductive polymer resin may be used to fix the soft magnetic substrate and the protective case. In general, a soldering method may be used, but the conductive polymer resin may be used to prevent the soft magnetic substrate from being cracked or cracked. Herein, the conductive polymer resin may include a metal material such as silver or copper or a conductive carbon material to electrically connect the ground and the protective case of the soft magnetic material, and is plated with an amorphous material as a conductive material. It may include. Therefore, the conductive polymer resin may be used to fix the soft magnetic substrate to the protective case and to electrically connect the soft magnetic substrate to the protective case.

The present invention is not limited to the above-described embodiments and the accompanying drawings. It will be apparent to those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

1: insertion groove 10: transmission line
20: soft magnetic substrate 30a: through capacitor
30b: multilayer ceramic capacitor 30c: dielectric substrate
31, 31 '; Electrode 32: Dielectric
40: protective case 50: PCB substrate
S10: circuit printing step S20: capacitor connection step
S30: Bonding Step

Claims (10)

A transmission line for transmitting an electrical signal;
A soft magnetic substrate including a printed circuit on a surface thereof and through which the transmission line passes; And
EMI connector filter one end of which is connected to the transmission line, and the other end of the capacitor connected to the ground of the printed circuit.
The method of claim 1, wherein the soft magnetic substrate is
EMI connector filter having a spinel structure or a garnet structure and providing an inductance to the transmission line through.
2. The apparatus of claim 1, wherein the capacitor
EMI connector filter in which the electrode and the dielectric is laminated in the longitudinal direction of the transmission line, the through-type capacitor penetrated by the transmission line.
2. The apparatus of claim 1, wherein the capacitor
An EMI connector filter provided on the printed circuit, which is a multilayer ceramic capacitor (MLCC) formed by repeatedly stacking electrodes and dielectrics.
The method of claim 1,
Further comprising a protective case for protecting the transmission line, the soft magnetic substrate and the capacitor from the outside,
The protective case is an EMI connector filter bonded to the soft magnetic material by a conductive polymer resin.
A transmission line for transmitting an electrical signal;
A dielectric substrate including plating on a surface thereof and through which the transmission line passes; And
EMI connector filter including a printed circuit on the surface, and comprising a soft magnetic substrate through which the transmission line passes.
The method of claim 6, wherein the dielectric substrate
An EMI connector filter in which a predetermined area is plated and a ground is plated to provide a capacitance corresponding to the area of the electrode to the transmission line.
The method of claim 7, wherein the dielectric substrate
The EMI connector filter is stacked on the soft magnetic substrate, the electrode is connected to the transmission line and the ground is connected to the ground of the printed circuit.
The transmission line of claim 1, wherein the transmission line
EMI locking filter including a locking means formed in a direction perpendicular to the longitudinal direction of the transmission line, the distance that the transmission line penetrates through the soft magnetic substrate by the locking means.
The method of claim 1,
EMI connector filter of the soft magnetic substrate is circular or polygonal.

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