Laminated common mode filter

Abstract

The laminated common mode filter of the present invention includes a plurality of coils constituting mutually different channels, in which a plurality of coil patterns and a plurality of via conductors connecting the coil patterns are provided inside a coil stack, and the plurality of via conductors are distributed at positions not overlapping each other on a layout of the coil stack.

Description

Technical Field

[0001] The present invention relates to a stacked common mode filter that allows differential signal currents to pass through in an electronic device using high-speed signal lines and removes common mode noise currents. Background Art

[0002] Mobile terminals typically adopt the Mobile Industry Processor Interface (MIPI) D-PHY standard as the digital data transmission standard. The MIPI D-PHY standard is a digital data transmission standard that connects the main circuit of a mobile terminal to a display or camera, and refers to a method of transmitting data using differential signals on two transmission lines.

[0003] With the rapid increase in the amount of data transmitted and received within a mobile terminal, the mobile terminal requires a transmission method that can transmit and receive data at a faster speed than the MIPI D-PHY standard.

[0004] Therefore, in the mobile terminal industry, research has recently been carried out on applying the MIPI C-PHY standard to mobile terminals. The MIPI C-PHY standard uses three transmission lines, transmits different voltages from the transmitting side to each transmission line, and performs differential output on the receiving side by taking the difference between the lines.

[0005] The content described in the background art is for helping to understand the background of the present invention and may include content that does not belong to the publicly available prior art. Summary of the Invention

[0006]

Technical Problem

[0007] The present invention is proposed in view of the above circumstances, and the object of the present invention is to provide a stacked common mode filter in which a stack including a capacitor pattern, a floating pattern, an inductor pattern, and a ground pattern is provided below the filter stack body, thereby enabling control of characteristics such as resonance points (resonance frequencies) and cut-offs.

[0008] In addition, another object of the present invention is to provide a stacked common mode filter in which a plurality of via conductors respectively including vias for connecting coil patterns are distributed in a non-overlapping manner, thereby preventing defects from occurring during the stacking process and enabling adjustment of filter characteristics.

[0009]

Technical Problem

[0010]

Technical Solution for Solving the Problem

[0011] To achieve the above object, a stacked common mode filter according to an embodiment of the present invention may include: a first stack provided with a first coil pattern, a second coil pattern, and a third coil pattern; and a second stack provided with a fourth coil pattern, a fifth coil pattern, and a sixth coil pattern, and disposed below the first stack to form a coil stack together with the first stack. The coil stack may include: a first via conductor connected to the first coil pattern in the first stack; a second via conductor connected to the sixth coil pattern in the second stack; a third via conductor connected to the second coil pattern and the third coil pattern in the first stack; and a fourth via conductor connected to the fourth coil pattern and the fifth coil pattern in the second stack. In a top view of the coil stack, the fourth via conductor may be disposed at a position not overlapping with the first via conductor, the second via conductor, and the third via conductor.

[0012] The first stack may further include a first terminal pattern and a second terminal pattern. The second stack may further include a third terminal pattern and a fourth terminal pattern. The first via conductor may connect the first coil pattern to the first terminal pattern in the first stack. The second via conductor may connect the sixth coil pattern to the fourth terminal pattern in the second stack. The third via conductor may connect the second coil pattern and the third coil pattern to the second terminal pattern in the first stack. The fourth via conductor may connect the fourth coil pattern and the fifth coil pattern to the third terminal pattern in the second stack.

[0013] In a top view of the coil stack, the third via conductor is disposed at a position not overlapping with the first via conductor and the second via conductor, and the first via conductor may be disposed at a position not overlapping with the second via conductor. Alternatively, the first via conductor may be disposed at a position overlapping with the second via conductor.

[0014] In a vertical cross-sectional view of the coil stack, the first via conductor may be spaced apart from the second via conductor, the third via conductor and the fourth via conductor may be spaced apart from each other between the first via conductor and the second via conductor, and the third via conductor may be between the first via conductor and the fourth via conductor.

[0015] In a vertical cross-sectional view of the coil stack, the third via conductor may be spaced apart from the fourth via conductor, the first via conductor and the second via conductor may be spaced apart from each other between the third via conductor and the fourth via conductor, and the first via conductor may be between the second via conductor and the third via conductor.

[0016] In a vertical cross-sectional view of the coil stack, the third via conductor may be spaced apart from the fourth via conductor, and the first via conductor and the second via conductor may be interposed between the third via conductor and the fourth via conductor and may be arranged to overlap in a top view of the coil stack.

[0017]

Advantages of the Invention

[0018] According to the present invention, the laminated common-mode filter allows the distance (pitch) between the coil patterns of each channel to be kept constant, so that the resistance and inductance of the coil patterns forming each channel are consistent.

[0019] In addition, by providing terminal patterns for connection to external electrodes at the uppermost and lowermost portions of the filter stack, the laminated common-mode filter has the effect of minimizing changes in the inductance characteristics and common-mode attenuation characteristics of the coil patterns.

[0020] In addition, by placing a capacitor pattern and a floating pattern below the coil stack, an additional depression is formed in the common-mode attenuation characteristic, whereby the laminated common-mode filter has the effect of expanding the attenuation frequency band.

[0021] In addition, the laminated common-mode filter achieves broadband characteristics through the additional poles (i.e., additional capacitance) formed by the capacitor pattern and the floating pattern and the poles formed by the coil patterns of the electrode stack.

[0022] In addition, by forming a preset distance (pitch) between the channels, the laminated common-mode filter has the effect of minimizing changes in the inductance characteristics of the coil patterns.

[0023] In addition, the laminated common-mode filter has the effect of enhancing the magnetic coupling (i.e., electromagnetic coupling) between the first coil to the third coil and minimizing the attenuation of differential signals.

[0024] In addition, the laminated common-mode filter can form the electrode stack by stacking sheets having two or fewer vias, so that the manufacturing process can be simplified.

[0025] That is, in the laminated common-mode filter, the terminal patterns are provided at the uppermost and lowermost portions of the electrode stack, the second coil pattern and the third coil pattern of the second channel are located between the first coil pattern and the sixth coil pattern of the first channel, and the fourth coil pattern and the fifth coil pattern of the third channel are located between the third coil pattern and the sixth coil pattern. Therefore, the number of vias required to connect the coil patterns can be minimized, and two or fewer vias are formed in each sheet.

[0026] In addition, the stacked common mode filter has the effect of increasing capacitance without adding an electrode layer including a coil pattern or increasing the area of the coil pattern, thereby achieving a larger capacitance than the conventional stacked common mode filter within the same size.

[0027] In addition, the stacked common mode filter has the effect of changing the second resonance frequency by adjusting the length of the inductor pattern.

[0028] In addition, since a short - circuit circuit formed by the floating pattern, the inductor pattern, and the ground pattern is configured by a third stack disposed below the coil stack, the stacked common mode filter can easily adjust and control the second resonance frequency.

[0029] In addition, by placing or removing a magnetic sheet at the lowermost part of the filter stack, the stacked common mode filter has the effect of being able to adjust the distance between the first resonance frequency and the second resonance frequency.

[0030] The stacked common mode filter according to an embodiment of the present invention can disperse pressure by dispersedly arranging via conductors in a non - overlapping manner, thereby preventing pressure concentration in the area where the via conductors are located during the stacking process.

[0031] In addition, since the pressure applied to the stack is dispersed by the dispersed arrangement of the via conductors during the stacking process, the stacked common mode filter according to an embodiment of the present invention can prevent cracks from forming in the stack during the stacking process.

[0032] In addition, since the pressure applied to the stack during the stacking process is dispersed by the dispersed arrangement of the via conductors, the stacked common mode filter according to an embodiment of the present invention can prevent the occurrence of a short - circuit by avoiding electrode compression caused by pressure concentration.

[0033] In addition, due to the dispersed arrangement of the via conductors, the stacked common mode filter according to an embodiment of the present invention can flatten the surface of the stack by preventing unevenness between the via conductor region and the surrounding region during the stacking process.

[0034] In addition, the stacked common mode filter according to an embodiment of the present invention can uniformly disperse pressure during the stacking process through the overlapping distribution of relatively thin via conductors having a first thickness and the dispersed arrangement of relatively thick via conductors having a second thickness, thereby being able to prevent cracks from occurring in the stack and being able to flatten the surface of the stack.

[0035] In addition, the stacked common-mode filter according to an embodiment of the present invention can adjust (tune) the characteristics of the filter by adjusting the distance between via conductors. Here, the stacked common-mode filter according to an embodiment of the present invention can improve the noise attenuation performance by reducing the first distance and / or the second distance, and increase the cut-off frequency by widening the first distance and / or the second distance, thereby improving the high-speed signal transmission characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a perspective view of a stacked common-mode filter according to an embodiment of the present invention.

[0037] Figure 2 is for explaining Figure 1 the exploded perspective view of the filter stack in

[0038] Figure 3 is for explaining Figure 2 the exploded perspective view of the first stack in

[0039] Figure 4 is for explaining Figure 3 the drawing of the first thin sheet in

[0040] Figure 5 is for explaining Figure 3 the drawing of the second thin sheet in

[0041] Figure 6 is for explaining Figure 3 the drawing of the third thin sheet in

[0042] Figure 7 is for explaining Figure 3 the drawing of the fourth thin sheet in

[0043] Figure 8 is for explaining Figure 2 the exploded perspective view of the second stack in

[0044] Figure 9 is for explaining Figure 3 the drawing of the fifth thin sheet in

[0045] Figure 10 is for explaining Figure 8 the drawing of the sixth thin sheet in

[0046] Figure 11 is for explaining Figure 8 the drawing of the seventh thin sheet in

[0047] Figure 12 is for explaining Figure 8 the drawing of the eighth thin sheet in

[0048] Figures 13 to 16 is showingFigure 2 Cross-sectional view of the vertical cross-section of the coil stack in

[0049] Figure 17 is for explaining Figure 2 Exploded perspective view of the third stack in

[0050] Figure 18 is for explaining Figure 17 Diagram of the ninth sheet in

[0051] Figure 19 is for explaining Figure 17 Diagram of the tenth sheet in

[0052] Figure 20 is for explaining Figure 17 Diagram of the eleventh sheet in

[0053] Figure 21 and 22 is for explaining Figure 17 Diagram of the twelfth sheet in

[0054] Figure 23 is for explaining Figure 17 Diagram of the thirteenth sheet in

[0055] Figure 24 Diagram showing the equivalent circuit of a stacked common-mode filter according to an embodiment of the present invention.

[0056] Figures 25 to 27 Diagram for comparing and explaining how the characteristics of a stacked common-mode filter change with the length (area) of the inductor pattern.

[0057] Figure 28 and 29 Exploded perspective view for explaining a modification example of a stacked common-mode filter according to an embodiment of the present invention.

[0058] Figure 30 and 31 is for comparing and explaining Figure 29 Diagram of the characteristics of a stacked common-mode filter with or without the third magnetic sheet shown in

[0059] Figures 32 to 34 Diagram for comparing and explaining the characteristics of a stacked common-mode filter according to an embodiment of the present invention and an existing stacked common-mode filter. Detailed Description of the Invention

[0060] Embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0061] The provided embodiments are to more comprehensively illustrate the present invention to those skilled in the art to which the present invention pertains. The following embodiments can be modified in various other forms, and the scope of the present invention is not limited to the following embodiments. These embodiments are provided to make the present invention more thorough and complete, and to fully convey the idea of the present invention.

[0062] The terms used in this specification are for describing specific embodiments and are not intended to limit the present invention. In addition, in this specification, unless otherwise clearly defined in the context, singular expressions may include plural expressions.

[0063] In the description of the embodiments, when it is described that each layer (film), region, pattern or structure is formed "on" or "under" each substrate, layer (film), region, pad or pattern, this includes two expressions, that is, including forming a layer "directly" on another layer or "indirectly" inserting another layer between two layers. In addition, the reference of "on" or "under" of each layer is based on the drawings.

[0064] The drawings are only for helping to understand the spirit of the present invention and should not be construed as limiting the scope of the present invention. In addition, in the drawings, for the convenience and clarity of illustration, relative thickness, length or size may be enlarged.

[0065] See Figure 1 , according to an embodiment of the present invention, the stacked common-mode filter 100 includes a filter stack 110, a first outer electrode 120, a second outer electrode 130, a third outer electrode 140, a fourth outer electrode 150, a fifth outer electrode 160, a sixth outer electrode 170, a seventh outer electrode 180, and an eighth outer electrode 190. Hereinafter, the stacked common-mode filter 100 operating as a three-channel C-PHY common-mode filter will be taken as an example for illustration.

[0066] The filter stack 110 is a stack of thin sheets, and six coil patterns forming three channels, capacitor patterns for adjusting characteristics such as resonance frequency, a floating pattern 522, inductor patterns 532 and 542, and a ground pattern 555 are arranged on the thin sheets. The stacked common-mode filter 100 adjusts the resonance point (resonance frequency) offset, cut-off characteristics, etc. through the capacitor patterns and the floating pattern 522 forming capacitance, the inductor patterns 532 and 542 constituting inductance, and the ground pattern 555 forming grounding.

[0067] See Figure 2 , the filter stack 110 includes a first stack 200, a second stack 300 disposed below the first stack 200, and a third stack 500 disposed below the second stack 300.

[0068] The first stack 200 is formed by stacking a plurality of thin sheets formed with metal patterns. For example, seeFigure 3 The first stacked body 200 includes a first thin sheet 210, a second thin sheet 220 disposed below the first thin sheet 210, a third thin sheet 230 disposed below the second thin sheet 220, and a fourth thin sheet 240 disposed below the third thin sheet 230.

[0069] Here, metal patterns corresponding to the terminal patterns 212 and 214 are formed in the first thin sheet 210, and metal patterns corresponding to the coil patterns 222, 232, and 242 are formed in the second thin sheet 220, the third thin sheet 230, and the fourth thin sheet 240.

[0070] See Figure 4 , a first terminal pattern 212 and a second terminal pattern 214 for connecting the coil pattern of the first electrode layer to the external electrode are formed on the first thin sheet 210.

[0071] The first terminal pattern 212 is located on the upper surface of the first thin sheet 210. The first end portion 212a of the first terminal pattern 212 is arranged adjacent to the center of the first thin sheet 210.

[0072] The second end portion 212b of the first terminal pattern 212 is arranged to align with the first side surface of the first thin sheet 210. Therefore, the second end portion 212b of the first terminal pattern 212 is exposed on the first side surface of the filter stacked body 110 and is connected to the first external electrode 120.

[0073] The second terminal pattern 214 is arranged on the upper surface of the first thin sheet 210 at an interval from the first terminal pattern 212. The first end portion 214a of the second terminal pattern 214 is arranged adjacent to the center of the first thin sheet 210. The first end portion 214a of the second terminal pattern 214 is separated from the first end portion 212a of the first terminal pattern 212 by a preset distance.

[0074] The second end portion 214b of the second terminal pattern 214 is arranged to align with the first side surface of the first thin sheet 214. Therefore, the second end portion 214b of the second terminal pattern 214 is separated from the second end portion 212b of the first terminal pattern 212 by a preset distance, exposed on the first side surface of the filter stacked body 110, and connected to the third external electrode 140.

[0075] See Figure 5 , the second thin sheet 220 is disposed below the first thin sheet 210. A first via hole V1 and a first coil pattern 222 forming a first channel are provided in the second thin sheet 220.

[0076] The first coil pattern 222 is disposed on the upper surface of the second sheet 220. The first coil pattern 222 is wound multiple times on the upper surface of the second sheet 220, thereby forming a first annular structure. The first coil pattern 222 is wound multiple times around a virtual winding axis passing through the center of the second sheet 220 to form a first annular structure.

[0077] The first end 222a of the first coil pattern 222 is disposed in the inner peripheral region of the first annular structure and is adjacent to the center of the second sheet 220. The first end 222a of the first coil pattern 222 is connected to the first end 212a of the first terminal pattern 212 through a via hole.

[0078] The second end 222b of the first coil pattern 222 is disposed in the outer peripheral region of the first annular structure and is aligned with the second side surface of the second sheet 220. Accordingly, the second end 222b of the first coil pattern 222 is exposed on the second side surface of the filter stack 110 and is connected to the fourth outer electrode 150.

[0079] The first via hole V1 is disposed adjacent to the center of the second sheet 220 and is spaced apart from the first end 222a of the first coil pattern 222. The first via hole V1 penetrates through the second sheet 220. The upper portion of the first via hole V1 is connected to the second terminal pattern 214. The lower portion of the first via hole is connected to a coil pattern formed in the third sheet 230, which will be described below.

[0080] See Figure 6 , the third sheet 230 is disposed below the second sheet 220, and a second coil pattern 232 for forming a second channel is provided in the third sheet 230.

[0081] The second coil pattern 232 is disposed on the upper surface of the third sheet 230. The second coil pattern 232 is wound multiple times on the upper surface of the third sheet 230, thereby forming a second annular structure. The second coil pattern 232 is wound multiple times around a virtual winding axis passing through the center of the third sheet 230 to form a second annular structure.

[0082] The first end 232a of the second coil pattern 232 is disposed in the inner peripheral region of the second annular structure and is adjacent to the center of the third sheet 230. The first end 232a of the second coil pattern 232 is connected to the first end 214a of the second terminal pattern 214 through the first via hole V1 of the second sheet 220.

[0083] The second end 232b of the second coil pattern 232 is disposed in the outer peripheral region of the second annular structure and aligned with the second side surface of the third sheet 230. The second end 232b of the second coil pattern 232 is disposed at a preset distance from the second end 222b of the first coil pattern 222, exposed on the second side surface of the filter stack 110, and connected to the fifth external electrode 160.

[0084] See Figure 7 , the fourth sheet 240 is disposed below the third sheet 230, and a third coil pattern 242 that forms a second channel together with the second coil pattern 232 is provided on the fourth sheet 240.

[0085] The third coil pattern 242 is disposed on the upper surface of the fourth sheet 240. The third coil pattern 242 is wound multiple times on the upper surface of the fourth sheet 240 to form a third annular structure. The third coil pattern 242 is wound multiple times around a virtual winding axis passing through the center of the fourth sheet 240 to form a third annular structure.

[0086] The first end 242a of the third coil pattern 242 is disposed in the inner peripheral region of the third annular structure, adjacent to the center of the fourth sheet 240. The first end 242a of the third coil pattern 242 is connected to the first end 232a of the second coil pattern 232 through a via hole and connected to the first end 214a of the second terminal pattern 214 through the first via hole V1 of the second sheet 220.

[0087] The second end 242b of the third coil pattern 242 is disposed in the outer peripheral region of the third annular structure and aligned with the second side surface of the fourth sheet 240. Therefore, the second end 242b of the third coil pattern 242 is disposed at a preset distance from the second end 222b of the first coil pattern 222.

[0088] The second end 242b of the third coil pattern 242 is disposed to be aligned with the second end 232b of the second coil pattern 232 and exposed on the second side surface of the filter stack 110 to be connected to the fifth external electrode 160 together with the second end 232b of the second coil pattern 232.

[0089] The second stack 300 is disposed below the first stack 200 and is formed by stacking a plurality of sheets formed with metal patterns. For example, see Figure 8, the second stack 300 includes a fifth sheet 310, a sixth sheet 320 located below the fifth sheet 310, a seventh sheet 330 located below the sixth sheet 320, and an eighth sheet 340 located below the seventh sheet 330. Here, metal patterns corresponding to the coil patterns 312, 322, 332 are formed in the fifth sheet 310, the sixth sheet 320, and the seventh sheet 330, and metal patterns corresponding to the terminal patterns 342, 344 are formed in the eighth sheet 340.

[0090] See Figure 9 , the fifth sheet 310 is disposed below the fourth sheet 240, and the fourth coil pattern 312 forming the third channel is disposed in the fifth sheet 310.

[0091] The fourth coil pattern 312 is located on the upper surface of the fifth sheet 310. The fourth coil pattern 312 is wound multiple times on the upper surface of the fifth sheet 310, thereby forming a fourth annular structure. The fourth coil pattern 312 is wound multiple times around a virtual winding axis passing through the center of the fifth sheet 310 to form a fourth annular structure.

[0092] The first end 312a of the fourth coil pattern 312 is disposed in the inner peripheral region of the fourth annular structure and is adjacent to the center of the fifth sheet 310. The first end 312a of the fourth coil pattern 312 is connected to the first end 322a of the fifth coil pattern 322 to be described below through a via hole.

[0093] The second end 312b of the fourth coil pattern 312 is located in the outer peripheral region of the fourth annular structure and is aligned with the second side surface of the fifth sheet 310. The second end 312b of the fourth coil pattern 312 is exposed on the second side surface of the filter stack 110 and is connected to the sixth outer electrode 170.

[0094] See Figure 10 , the sixth sheet 320 is disposed below the fifth sheet 310. The fifth coil pattern 322 that forms the third channel together with the fourth coil pattern 312 is disposed in the sixth sheet 320.

[0095] The fifth coil pattern 322 is located on the upper surface of the sixth sheet 320. The fifth coil pattern 322 is wound multiple times on the upper surface of the sixth sheet 320, thereby forming a fifth annular structure. The fifth coil pattern 322 is wound multiple times around a virtual winding axis passing through the center of the sixth sheet 320 to form a fifth annular structure.

[0096] The first end 322a of the fifth coil pattern 322 is disposed in the inner peripheral region of the fifth annular structure and is adjacent to the center of the sixth sheet 320. The first end 322a of the fifth coil pattern 322 is connected to the first end 312a of the fourth coil pattern 312 through a via hole.

[0097] The second end portion 322b of the fifth coil pattern 322 is disposed in the outer peripheral region of the fifth annular structure and is aligned with the second side surface of the sixth sheet 320. The second end portion 322b of the fifth coil pattern 322 is aligned with the second end portion 312b of the fourth coil pattern 312 and is exposed on the second side surface of the filter stack 110 to be connected to the sixth external electrode 170 together with the second end portion 312b of the fourth coil pattern 312.

[0098] See Figure 11 , the seventh sheet 330 is located below the sixth sheet 320, and a second via hole V2 and a sixth coil pattern 332 that forms a first channel together with the first coil pattern 222 of the first stack 200 are formed in the seventh sheet 330.

[0099] The sixth coil pattern 332 is located on the upper surface of the seventh sheet 330. The sixth coil pattern 332 is wound multiple times on the upper surface of the seventh sheet 330, thereby forming a sixth annular structure. The sixth coil pattern 332 is wound multiple times around a virtual winding axis passing through the center of the seventh sheet 330 to form a sixth annular structure.

[0100] The first end portion 332a of the sixth coil pattern 332 is disposed in the inner peripheral region of the sixth annular structure and is adjacent to the center of the seventh sheet 330.

[0101] The second end portion 332b of the sixth coil pattern 332 is disposed in the outer peripheral region of the sixth annular structure and is aligned with the second side surface of the seventh sheet 330. The second end portion 332b of the sixth coil pattern 332 is disposed at a preset distance from the second end portion 312b of the fourth coil pattern 312 and the second end portion 322b of the fifth coil pattern 322, and is exposed on the second side surface of the filter stack 110 to be connected to the fourth external electrode 150.

[0102] The second via hole V2 is disposed adjacent to the center of the seventh sheet 330 and is spaced apart from the first end portion 332a of the sixth coil pattern 332. The second via hole V2 is formed to penetrate the seventh sheet 330. The upper portion of the second via hole V2 is connected to the first end portion 312a of the fourth coil pattern 312 and the first end portion 322a of the fifth coil pattern 322. The lower portion of the second via hole V2 is connected to a third terminal pattern 342 formed in an eighth sheet 340, which will be described below.

[0103] See Figure 12 , a third terminal pattern 342 and a fourth terminal pattern 344 for connecting the coil pattern of the second electrode layer to an external electrode are formed in the eighth sheet 340.

[0104] The third terminal pattern 342 is located on the upper surface of the eighth sheet 340. The first end 342a of the third terminal pattern 342 is arranged adjacent to the center of the eighth sheet 340. The first end 342a of the third terminal pattern 342 is connected to the first end 312a of the fourth coil pattern 312 and the first end 322a of the fifth coil pattern 322 through the second via V2.

[0105] The second end 342b of the third terminal pattern 342 is arranged to align with the first side surface of the eighth sheet 340. Thus, the second end 342b of the third terminal pattern 342 is exposed on the first side surface of the filter stack 110 and is connected to the second external electrode 130.

[0106] The fourth terminal pattern 344 is located on the upper surface of the eighth sheet 340, spaced apart from the third terminal pattern 342. The first end 344a of the fourth terminal pattern 344 is connected to the first end 332a of the sixth coil pattern 332 through a via. The first end 344a of the fourth terminal pattern 344 is arranged adjacent to the center of the eighth sheet 340. The first end 344a of the fourth terminal pattern 344 is separated from the first end 342a of the third terminal pattern 342 by a preset distance.

[0107] The second end 344b of the fourth terminal pattern 344 is arranged to align with the first side surface of the eighth sheet 340. Therefore, the second end 344b of the fourth terminal pattern 344 is separated from the second end 342b of the third terminal pattern 342 by a preset distance and is exposed on the first side surface of the filter stack 110 to be connected to the first external electrode 120 together with the second end 212b of the first terminal pattern 212.

[0108] The first stack 200 and the second stack 300 form a coil stack 400, and the coil stack 400 includes coils forming three channels.

[0109] The coil stack 400 is configured such that the first coil pattern 222, the second coil pattern 232, the third coil pattern 242, the fourth coil pattern 312, the fifth coil pattern 322, and the sixth coil pattern 332 are stacked in sequence.

[0110] Here, the first coil pattern 222 and the sixth coil pattern 332 form a first coil, and the first coil is a series inductor constituting the first channel. The second coil pattern 232 and the third coil pattern 242 form a second coil, and the second coil is a series inductor constituting the second channel. The fourth coil pattern 312 and the fifth coil pattern 322 form a third coil, and the third coil is a series inductor constituting the third channel.

[0111] Accordingly, the coil stack 400 forms a stack in which the coil patterns of the first channel, the coil patterns of the second channel, the coil patterns of the second channel, the coil patterns of the third channel, the coil patterns of the third channel, and the coil patterns of the first channel are arranged (stacked) in sequence.

[0112] Therefore, in the stacked common-mode filter 100 according to an embodiment of the present invention, the distance (pitch) between the coil patterns forming each channel can be kept constant, so that the resistance and inductance of the coil patterns forming each channel are consistent.

[0113] In addition, the stacked common-mode filter 100 according to an embodiment of the present invention can minimize the change in the inductance characteristics and common-mode attenuation characteristics of the coil patterns by placing the terminal patterns for connection to the external electrodes at the uppermost and lowermost portions of the coil stack 400. When the terminal patterns are provided only at the uppermost or lowermost portion, the inductance characteristics of each channel change, or the inductance characteristics of each coil pattern change, resulting in a change in the common-mode attenuation characteristics.

[0114] In the stacked common-mode filter 100 according to an embodiment of the present invention, the terminal patterns are provided at the uppermost and lowermost portions of the coil stack 400, the second coil pattern 232 and the third coil pattern 242 of the second channel are provided between the first coil pattern 222 and the sixth coil pattern 332 of the first channel, and the fourth coil pattern 312 and the fifth coil pattern 322 of the third channel are provided between the first coil pattern 242 and the sixth coil pattern 332. Accordingly, the number of vias required to connect the coil patterns can be minimized. The stacked common-mode filter 100 according to an embodiment of the present invention forms two or fewer vias in each sheet.

[0115] See Figure 13 , the first coil pattern 222 and the sixth coil pattern 332 are respectively provided at the upper and lower portions of the filter stack 110 to form the first channel. The second coil pattern 232 and the third coil pattern 242 are arranged (stacked) parallel to each other between the first coil pattern 222 and the sixth coil pattern 332 to form the second channel. The fourth coil pattern 312 and the fifth coil pattern 322 are arranged (stacked) parallel to each other between the third coil and the sixth coil to form the third channel.

[0116] Therefore, the stacked common-mode filter 100 according to an embodiment of the present invention can be configured such that the distances (pitches) between the first channel and the second channel, the second channel and the third channel, and the third channel and the first channel are kept constant.

[0117] In addition, the stacked common-mode filter 100 according to an embodiment of the present invention can minimize the change in the inductance characteristics of the coil patterns by keeping the distance (interval) between the channels constant.

[0118] In addition, in the stacked common-mode filter 100 according to an embodiment of the present invention, since the terminal patterns connecting the coil patterns to the external electrodes are provided at the uppermost and lowermost portions of the filter stack 110, the distance between the coil patterns and the terminal patterns can be made the same for all channels, thereby ensuring that the resistance and inductance of the coil patterns forming each channel are consistent.

[0119] In addition, the stacked common-mode filter 100 according to an embodiment of the present invention can enhance the magnetic coupling (i.e., electromagnetic coupling) between the first coil to the third coil and minimize the attenuation of differential signals.

[0120] The coil stack 110 is configured such that a plurality of via conductors are distributed without overlapping each other, and the plurality of via conductors are formed by vias for connecting coil patterns and terminal patterns.

[0121] For example, referring to Figure 14 , the first via conductor 710 is formed by a via connecting the first terminal pattern 212 and the first coil pattern 222.

[0122] The second via conductor 720 is formed by a via connecting the fourth terminal pattern 344 and the sixth coil pattern 332, and when viewed from the upper surface or the lower surface of the coil stack 400 (i.e., in the top view of the coil stack 400), the second via conductor 720 is spaced apart from and does not overlap with the first via conductor 720.

[0123] The third via conductor 730 is formed by vias connecting the second terminal pattern 214, the second coil pattern 232, and the third coil pattern 242, and is spaced apart from the first via conductor 710 and the second via conductor 720 and does not overlap with the first via conductor 710 and the second via conductor 720 in the top view of the coil stack 400.

[0124] The fourth via conductor 740 is formed by vias connecting the third terminal pattern 342, the fourth coil pattern 312, and the fifth coil pattern 322, and is spaced apart from the first via conductor 710 to the third via conductor 730 and does not overlap with the first via conductor 710 to the third via conductor 730 in the top view of the coil stack 400.

[0125] In other words, the first virtual line L1 is defined as a line that passes through the upper surface and the lower surface of the coil stack 400 and intersects the center of the first via conductor 710 in the vertical cross-sectional view of the coil stack 400.

[0126] The second virtual line L2 is defined as: in a vertical cross-sectional view of the coil stack 400, a line that passes through the upper and lower surfaces of the coil stack 400 in the figure and intersects the center of the second via conductor 720. The second virtual line L2 is separated from the first virtual line L1 by a preset distance and is parallel to the first virtual line L1.

[0127] The third virtual line L3 is defined as: in a vertical cross-sectional view of the coil stack 400, a line that passes through the upper and lower surfaces of the coil stack 400 in the figure and intersects the center of the third via conductor 730. The third virtual line L3 is located between the first virtual line L1 and the second virtual line L2, is separated from the first virtual line L1 and the second virtual line L2 by a preset interval, and is parallel to the first virtual line L1 and the second virtual line L2.

[0128] The fourth virtual line L4 is defined as: in the figure, a line that passes through the upper and lower surfaces of the coil stack 400 and intersects the center of the fourth via conductor 730. The fourth virtual line L4 is located between the second virtual line L2 and the third virtual line L3, is separated from the second virtual line L2 and the third virtual line L3 by a preset interval, and is parallel to the first virtual line L1 to the third virtual line L3.

[0129] In another example, referring to Figure 15 , the coil stack 400 can be configured such that the first via conductor 710 and the second via conductor 720 are disposed between the third via conductor 730 and the fourth via conductor 740. In other words, the first virtual line L1 is disposed between the third virtual line L3 and the fourth virtual line L4, and the second virtual line L2 is disposed between the first virtual line L1 and the fourth virtual line L4. Here, the first virtual line L1 and the second virtual line L2 are parallel and do not overlap.

[0130] Thus, the stacked common mode filter 100 according to an embodiment of the present invention can disperse the pressure by dispersedly arranging the via conductors in a non-overlapping manner, thereby preventing pressure concentration in the area where the via conductors are located during the stacking process.

[0131] In addition, since the pressure applied to the stack is dispersed by the dispersed arrangement of the via conductors during the stacking process, the stacked common mode filter 100 according to an embodiment of the present invention can prevent cracks from forming in the stack during the stacking process.

[0132] In addition, since the pressure applied to the stack during the stacking process is dispersed by the dispersed arrangement of the via conductors, the stacked common mode filter 100 according to an embodiment of the present invention can prevent the occurrence of a short circuit by avoiding electrode compression caused by pressure concentration.

[0133] In addition, since the via conductors are dispersedly arranged, the stacked common mode filter 100 according to an embodiment of the present invention can flatten the surface of the stacked body by preventing unevenness between the via conductor regions and the surrounding regions during the stacking process.

[0134] In another example, referring to Figure 16 , the coil stack 400 can be configured such that the first via conductor 710 and the second via conductor 720 overlap each other. The third virtual line L3 and the fourth virtual line L4 are spaced apart from each other, and the first virtual line L1 and the second virtual line L2 are interposed between the third virtual line L3 and the fourth virtual line L4. Here, the first virtual line L1 and the second virtual line L2 overlap between the third virtual line L3 and the fourth virtual line L4.

[0135] Thus, since the first via conductor 710 and the second via conductor 720 having a relatively thin first thickness overlap, and the third via conductor 730 and the fourth via conductor 740 having a relatively thick second thickness are dispersedly arranged, the stacked common mode filter 100 according to an embodiment of the present invention can prevent cracks from occurring in the stacked body and flatten the surface of the stacked body by evenly dispersing pressure during the stacking process.

[0136] In the coil stack 400, an additional capacitance is formed by the coupling of two adjacent via conductors. That is, in the coil stack 400, a first additional capacitance is formed between the first via conductor 710 connected to the first channel (i.e., the first coil) and the third via conductor 730 connected to the second channel (i.e., the second coil). A second additional capacitance is formed between the second via conductor 720 connected to the first channel (i.e., the first coil) and the fourth via conductor 730 connected to the third channel (i.e., the third coil).

[0137] In addition, the stacked common mode filter 100 according to an embodiment of the present invention can adjust (tune) the characteristics of the filter by adjusting the distance between the via conductors. The stacked common mode filter 100 can adjust the characteristics of the filter by controlling at least one of the first distance (i.e., the distance between the first via conductor 710 and the third via conductor 730) and the second distance (i.e., the distance between the second via conductor 720 and the fourth via conductor 740).

[0138] The stacked common mode filter 100 according to an embodiment of the present invention can improve the noise attenuation performance by reducing the first distance and / or the second distance, and increase the cut-off frequency by widening the first distance and / or the second distance, thereby improving the high-speed signal transmission characteristics.

[0139] The third stack 500 is disposed below the second stack 300. The third stack 500 is formed by stacking a plurality of sheets formed with metal patterns.

[0140] For example, refer to Figure 17 , the third stacked body 500 includes a ninth thin sheet 510, a tenth thin sheet 520 located below the ninth thin sheet 510, an eleventh thin sheet 530 located below the tenth thin sheet 520, a twelfth thin sheet 540 located below the eleventh thin sheet 530, and a thirteenth thin sheet 510 located below the twelfth thin sheet 540. Metal patterns 411 to 416 and 422 for forming a capacitor are formed on the ninth thin sheet 510 and the tenth thin sheet 520. Metal patterns 432 and 442 for forming an inductor are formed on the eleventh thin sheet 530 and the twelfth thin sheet 540. A metal pattern 452 for forming a ground is formed on the thirteenth thin sheet 510.

[0141] The ninth thin sheet 510 is 340 below the eighth thin sheet. A plurality of capacitor patterns are disposed on the upper surface of the ninth thin sheet 510, and the capacitor patterns can be set as a plurality of patterns provided at the input end and the output end of the stacked common mode filter 100.

[0142] For example, refer to Figure 18 , the capacitor patterns include a first capacitor pattern 511, a second capacitor pattern 512, a third capacitor pattern 513, a fourth capacitor pattern 514, a fifth capacitor pattern 515, and a sixth capacitor pattern 516.

[0143] The first capacitor pattern 511 is disposed on the upper surface of the ninth thin sheet 510.

[0144] The first end portion 511a of the first capacitor pattern 511 is disposed adjacent to the center of the ninth thin sheet 510.

[0145] The second end portion 511b of the first capacitor pattern 511 is disposed to align with the first side surface of the ninth thin sheet 510. The first capacitor pattern 511 is exposed on the first side surface of the filter stacked body 110 and is connected to the first external electrode 120.

[0146] The second capacitor pattern 512 is disposed on the upper surface of the ninth thin sheet 510, spaced apart from the first capacitor pattern 511. The second capacitor pattern 512 is spaced apart from the first capacitor pattern 511 and is biased toward the fourth side surface of the ninth thin sheet 510.

[0147] The first end portion 512a of the second capacitor pattern 512 is disposed adjacent to the center of the ninth thin sheet 510. The second end portion 512b of the second capacitor pattern 512 is disposed to align with the first side surface of the ninth thin sheet 510. The second capacitor pattern 512 is exposed on the first side surface of the filter stacked body 110 and is connected to the second external electrode 130.

[0148] The third capacitor pattern 513 is disposed on the upper surface of the ninth sheet 510. The third capacitor pattern 513 is spaced apart from the first capacitor pattern 511 and the second capacitor pattern 512 and is biased toward the third side surface of the ninth sheet 510. The third capacitor pattern 513 is disposed opposite to the second capacitor 512, and the first capacitor pattern 511 is disposed between the third capacitor pattern 513 and the second capacitor 512.

[0149] The first end portion 513a of the third capacitor pattern 513 is disposed adjacent to the center of the ninth sheet 510. The second end portion 513b of the third capacitor pattern 513 is disposed to align with the first side surface of the ninth sheet 510. The third capacitor pattern 513 is exposed on the first side surface of the filter stack 110 and is connected to the third external electrode 140.

[0150] The fourth capacitor pattern 514 is disposed on the upper surface of the ninth sheet 510.

[0151] The first end portion 514a of the fourth capacitor pattern 514 is disposed adjacent to the center of the ninth sheet 510. The first end portion 514a of the fourth capacitor pattern 514 faces the first end portion 511a of the first capacitor pattern 511.

[0152] The second end portion 514b of the fourth capacitor pattern 514 is disposed to align with the second side surface of the ninth sheet 510. The fourth capacitor pattern 514 is exposed on the second side surface of the filter stack 110 and is connected to the fourth external electrode 150.

[0153] The fifth capacitor pattern 515 is disposed on the upper surface of the ninth sheet 510. The fifth capacitor pattern 515 is spaced apart from the fourth capacitor pattern 514 and is biased toward the third side surface of the ninth sheet 510.

[0154] The first end portion 515a of the fifth capacitor pattern 515 is disposed adjacent to the center of the ninth sheet 510. The first end portion 515a of the fifth capacitor pattern 515 faces the first end portion 513a of the third capacitor pattern 513.

[0155] The second end portion 515b of the fifth capacitor pattern 515 is disposed to align with the second side surface of the ninth sheet 510. The fifth capacitor pattern 515 is exposed on the second side surface of the filter stack 110 and is connected to the fifth external electrode 160.

[0156] The sixth capacitor pattern 516 is disposed on the upper surface of the ninth sheet 510. The sixth capacitor pattern 516 is spaced apart from the fourth capacitor pattern 514 and the fifth capacitor pattern 515 and is biased toward the fourth side surface of the ninth sheet 510. The sixth capacitor pattern 516 is disposed opposite to the fifth capacitor pattern 515, and the fourth capacitor pattern 514 is interposed between the sixth capacitor pattern 516 and the fifth capacitor pattern 515.

[0157] The first end portion 516a of the sixth capacitor pattern 516 is disposed adjacent to the center of the ninth sheet 510. The first end portion 516a of the sixth capacitor pattern 516 faces the first end portion 512a of the second capacitor pattern 512.

[0158] The second end portion 516b of the sixth capacitor pattern 516 is disposed to be aligned with the second side surface of the ninth sheet 510. The sixth capacitor pattern 516 is exposed on the second side surface of the filter stack 110 and is connected to the sixth external electrode 170.

[0159] Assuming that the first to third external electrodes 120 to 140 disposed on the first side surface of the filter stack 110 are used as the input terminals of the stacked common mode filter 100, the third to sixth external electrodes 140 to 170 disposed on the second side surface of the filter stack 110 are used as the output terminals of the stacked common mode filter 100.

[0160] The first to third capacitor patterns 511 to 513 are disposed on the first side surface of the filter stack 110 and are respectively connected to the first to third external electrodes 120 to 140 in a one-to-one correspondence. The fourth to sixth capacitor patterns 514 to 516 are disposed on the second side surface of the filter stack 110 and are respectively connected to the fourth to fifth external electrodes 150 to 160 in a one-to-one correspondence.

[0161] The filter stack 110 may include the ninth sheet 510 formed with the first to third capacitor patterns 511 to 513 connected to the input terminal for adjusting and controlling the capacitance characteristics, or may include the ninth sheet 510 formed with the fourth to sixth capacitor patterns 514 to 516 connected to the output terminal.

[0162] The tenth sheet 520 is disposed below the ninth sheet 510. The floating pattern 522 for forming capacitance is disposed on the upper surface of the tenth sheet 520 together with the capacitor pattern of the ninth sheet 510.

[0163] See Figure 19, the floating pattern 522 is formed in a plate shape and placed on the upper surface of the tenth sheet 520. The area of the floating pattern 522 is smaller than the area of the tenth sheet 520, and it is set such that the outer periphery of the floating pattern 522 is spaced apart from the four side surfaces of the tenth sheet 520. The area of the floating pattern 522 is larger than the areas of the first inductor pattern 532 and the second inductor pattern 542, which will be described later, and is formed to be 90% or less of the area of the tenth sheet 520.

[0164] The floating pattern 522 overlaps with the capacitor pattern of the ninth sheet 510 to form an overlapping region, and a capacitance is formed in this overlapping region.

[0165] The floating pattern 522 forms a first overlapping region 522a with the first capacitor pattern 511, and a first capacitance is formed in the first overlapping region 522a. The floating pattern 522 forms a second overlapping region 522b with the second capacitor pattern 512, and a second capacitance is formed in the first overlapping region 522a. The floating pattern 522 forms a third overlapping region 522c with the third capacitor pattern 513, and a third capacitance is formed in the first overlapping region 522a. The floating pattern 522 forms a fourth overlapping region 522d with the fourth capacitor pattern 514, and a fourth capacitance is formed in the first overlapping region 522a. The floating pattern 522 forms a fifth overlapping region 522e with the fifth capacitor pattern 515, and a fifth capacitance is formed in the first overlapping region 522a. The floating pattern 522 forms a sixth overlapping region 522f with the sixth capacitor pattern 516, and a sixth capacitance is formed in the first overlapping region 522a.

[0166] Thus, the floating pattern 522 forms a capacitance with the capacitor pattern. Therefore, the stacked common-mode filter 100 can expand the attenuation band by forming an additional depression in the common-mode attenuation characteristic. That is, the stacked common-mode filter 100 can achieve broadband characteristics together with the poles formed by the coil pattern of the filter stack 110 by forming additional poles due to the floating pattern 522 and the capacitor pattern.

[0167] The eleventh sheet 530 is disposed below the tenth sheet 520. The first inductor pattern 532 is located on the upper surface of the eleventh sheet 530.

[0168] For example, referring to Figure 17 , the first inductor pattern 532 is wound around the upper surface of the eleventh sheet 530, thereby forming a seventh annular structure. The first inductor pattern 532 is wound around a virtual winding axis passing through the center of the eleventh sheet 530 to form a seventh annular structure.

[0169] The first end 532a of the first inductor pattern 532 is disposed in the inner peripheral region of the seventh annular structure and is located at the center of the eleventh sheet 530. The first end 532a of the first inductor pattern 532 is connected to the floating pattern 522 of the tenth sheet through a via hole.

[0170] The second end 532b of the first inductor pattern 532 is disposed in the outer peripheral region of the seventh annular structure.

[0171] The twelfth sheet 540 is located below the eleventh sheet 530, and the second inductor pattern 542 is located on the upper surface of the twelfth sheet 540.

[0172] For example, referring to Figure 21 , the second inductor pattern 542 is wound around the upper surface of the twelfth sheet 540, thereby forming an eighth annular structure. The second inductor pattern 542 is wound around a virtual winding axis passing through the center of the twelfth sheet 540 to form an eighth annular structure.

[0173] The first end 542a of the second inductor pattern 542 is located in the inner peripheral region of the eighth annular structure and is located at the center of the twelfth sheet 540. The first end 542a of the second inductor pattern 542 is connected to the ground pattern 555 of the thirteenth sheet 510 through a via hole passing through the twelfth sheet 540.

[0174] The second end 542b of the second inductor pattern 542 is located in the outer peripheral region of the eighth annular structure. The first end 542b of the second inductor pattern 542 is connected to the first inductor pattern 532 of the eleventh sheet 530 through a via hole. The second end 542b of the second inductor pattern 542 is connected to the second end 532b of the first inductor pattern 532 through a via hole.

[0175] Since the second end 532b of the first inductor pattern 532 and the second end 542b of the second inductor pattern 542 are connected through a via hole, the first inductor pattern 532 and the second inductor pattern 542 constitute a parallel common inductor, and the parallel common inductor forms a preset inductance.

[0176] Referring to Figure 22 , the lengths (areas) of the first inductor pattern 532 and the second inductor pattern 542 can be varied according to the desired sub-resonant frequency.

[0177] As the lengths of the first inductor pattern 532 and the second inductor pattern 542 increase, the inductance value increases, and the sub-resonant frequency shifts to a lower frequency. As the lengths of the first inductor pattern 532 and the second inductor pattern 542 decrease, the inductance value decreases, and the sub-resonant frequency shifts to a higher frequency.

[0178] Therefore, the lengths of the first inductor pattern 532 and the second inductor pattern 542 are determined based on the desired sub-resonant frequency. The first inductor pattern 532 and the second inductor pattern 542 may be formed to have the same length or different lengths.

[0179] The thirteenth sheet 510 is disposed below the twelfth sheet 540. The ground pattern 555 is formed in the thirteenth sheet 510.

[0180] The ground pattern 555 is connected to the inductor patterns 532 and 542 and reduces the influence of the stray capacitance formed between the stacked common-mode filter 100 and the printed circuit board.

[0181] For example, referring to Figure 23 , the ground pattern 555 is formed on the upper surface of the thirteenth sheet 510. The ground pattern 555 includes a first ground pattern 555a, a second ground pattern 555b, and a third ground pattern 555c.

[0182] The first ground pattern 555a is formed in a plate shape and is located at the center of the upper surface of the thirteenth sheet 510. The area of the first ground pattern 555a is smaller than the area of the thirteenth sheet 510, and the outer periphery of the first ground pattern 555a is spaced apart from the four side surfaces of the thirteenth sheet 510. The first ground pattern 555a is connected to the first end 542a of the second inductor pattern 542 through a via hole passing through the twelfth sheet 540.

[0183] The second ground pattern 555b extends from the third side of the first ground pattern 555a and is disposed to be aligned with the third side of the thirteenth sheet 510. The first end of the second ground pattern 555b is connected to the third side of the first ground pattern 555a. The second end of the second ground pattern 555b is disposed to be aligned with the third side of the thirteenth sheet 510 and is connected to the seventh outer electrode 180.

[0184] The third ground pattern 555c extends from the fourth side of the first ground pattern 555a and is disposed to be aligned with the fourth side of the thirteenth sheet 510. The first end of the third ground pattern 555c is connected to the fourth side of the first ground pattern 555a. The second end of the third ground pattern 555c is disposed to be aligned with the fourth side of the thirteenth sheet 510 and is connected to the eighth outer electrode 190.

[0185] Therefore, the ground pattern 555 is exposed on the third and fourth side surfaces of the filter stack 110, thereby forming a ground connection to the seventh outer electrode 180 and the eighth outer electrode 190.

[0186] The first external electrode 120 is located on the first side surface of the filter stack 110. Opposite ends of the first external electrode 120 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0187] The first external electrode 120 is connected to a first terminal pattern 212, a fourth terminal pattern 344, and a first capacitor pattern 511 that are exposed on the first side surface of the filter stack 110. In this case, the first external electrode 120 is connected to a second end portion 212b of the first terminal pattern 212, a second end portion 344b of the fourth terminal pattern 344, and a second end portion 511b of the first capacitor pattern 511a.

[0188] The second external electrode 130 is located on the first side surface of the filter stack 110. The second external electrode 130 is disposed to be biased toward the fourth side surface of the filter stack 110 and is spaced apart from the first external electrode 120. Opposite ends of the second external electrode 130 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0189] The second external electrode 130 is connected to a third terminal pattern 342 and a second capacitor pattern 512 that are exposed on the first side surface of the filter stack 110. The second external electrode 130 is connected to a second end portion 342b of the third terminal pattern 342 and a second end portion 512b of the second capacitor pattern 512.

[0190] The third external electrode 140 is located on the first side surface of the filter stack 110. The third external electrode 140 is disposed to be biased toward the third side surface of the filter stack 110 and is spaced apart from the first external electrode 120. The third external electrode 140 is opposite to the second external electrode 130, and the first external electrode 120 is interposed between the third external electrode 140 and the second external electrode 130. Opposite ends of the third external electrode 140 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0191] The third external electrode 140 is connected to a second terminal pattern 214 and a third capacitor pattern 513 that are exposed on the first side surface of the filter stack 110. The third external electrode 140 is connected to a second end portion 214b of the second terminal pattern 214 and a second end portion 513b of the third capacitor pattern 513.

[0192] The fourth external electrode 150 is located on the second side surface of the filter stack 110. The fourth external electrode 150 is opposite to the first external electrode 120, the filter stack 110 is interposed between the fourth external electrode 150 and the first external electrode 120, and the fourth external electrode 150 is disposed to face the first external electrode 120. Opposite ends of the fourth external electrode 150 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0193] The fourth external electrode 150 is connected to the first coil pattern 222, the sixth coil pattern 332, and the fourth capacitor pattern 514 that are exposed on the second side surface of the filter stack 110. The fourth external electrode 150 is connected to the second end 222b of the first coil pattern 222, the second end 332b of the sixth coil pattern 332, and the second end 514b of the fourth capacitor pattern 514.

[0194] The fifth external electrode 160 is located on the second side surface of the filter stack 110. The fifth external electrode 160 is opposite to the third external electrode 140, with the filter stack 110 interposed therebetween, and the fifth external electrode 160 is arranged to face the third external electrode 140. The fifth external electrode 160 is arranged to be biased towards the third side surface of the filter stack 110 and is spaced apart from the fourth external electrode 150. Opposite ends of the fifth external electrode 160 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0195] The fifth external electrode 160 is connected to the second coil pattern 232, the third coil pattern 242, and the fifth capacitor pattern 515 that are exposed on the second side surface of the filter stack 110. The fifth external electrode 160 is connected to the second end 232b of the second coil pattern 232, the second end 242b of the third coil pattern 242, and the second end 515b of the fifth capacitor pattern 515.

[0196] The sixth external electrode 170 is located on the second side surface of the filter stack 110. The sixth external electrode 170 is opposite to the second external electrode 130, with the filter stack 110 interposed therebetween, and the sixth external electrode 170 is arranged to face the second external electrode 130. The sixth external electrode 170 is arranged to be biased towards the fourth side surface of the filter stack 110 and is spaced apart from the fourth external electrode 150. The sixth external electrode 170 is opposite to the fifth external electrode 160, with the fourth external electrode 150 interposed therebetween. Opposite ends of the sixth external electrode 170 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0197] The sixth external electrode 170 is connected to the fourth coil pattern 312, the fifth coil pattern 322, and the sixth capacitor pattern 516 that are exposed on the second side surface of the filter stack 110. The sixth external electrode 170 is connected to the second end 312b of the fourth coil pattern 312, the second end 322b of the fifth coil pattern 322, and the second end 516b of the sixth capacitor pattern 516.

[0198] The seventh external electrode 180 is located on the third side surface of the filter stack 110. The seventh external electrode 180 is connected to the ground pattern 555 exposed on the third side surface of the filter stack 110. The seventh external electrode 180 is connected to the second end of the second ground pattern 555b exposed on the third side surface of the filter stack 110. Opposite ends of the seventh external electrode 180 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0199] The eighth external electrode 190 is located on the fourth side surface of the filter stack 110. The eighth external electrode 190 is opposite to the eighth external electrode 190, and the filter stack 110 is interposed between the eighth external electrode 190 and the eighth external electrode 190. The eighth external electrode 190 is connected to the ground pattern 555 exposed on the third side surface of the filter stack 110. The eighth external electrode 190 is connected to the second end of the third ground pattern 555c exposed on the fourth side surface of the filter stack 110. Opposite ends of the eighth external electrode 190 may be formed to extend to the upper and lower surfaces of the filter stack 110.

[0200] The first external electrode 120 and the fourth external electrode 150 serve as input and output terminals of a first channel formed by the first coil pattern 222 and the sixth coil pattern 332. The third external electrode 140 and the fifth external electrode 160 serve as input and output terminals of a second channel formed by the second coil pattern 232 and the third coil pattern 242. The second external electrode 130 and the sixth external electrode 170 serve as input and output terminals of a third channel formed by the fourth coil pattern 312 and the sixth coil pattern 332. The seventh external electrode 180 and the seventh external electrode 180 are connected to the ground pattern 555, thereby functioning as ground terminals.

[0201] Figure 24 An equivalent circuit of the stacked common-mode filter 100 according to an embodiment of the present invention is shown, and capacitances are formed between the first coil and the second coil, between the second coil and the third coil, and between the first coil and the third coil.

[0202] The filter stack 110 is formed by stacking the first stack 20 and the second stack 300 having coil patterns to form a coil stack 400, and placing a third stack 500 including capacitor patterns, a floating pattern 522, and inductor patterns 532 and 542 below the coil stack 400. Accordingly, the capacitor patterns connected between the coils and the external electrodes in each channel are interconnected, and a coupling effect is generated between the capacitor patterns and the floating pattern 522. Thereby, additional capacitances C1 to C6 are formed between the coils and the external electrodes in each channel due to the capacitor patterns and the floating pattern 522.

[0203] Therefore, the stacked common-mode filter 100 according to an embodiment of the present invention can increase capacitance without adding an electrode layer including a coil pattern or increasing the area of the coil pattern, thereby achieving a larger capacitance while maintaining the same size compared to the existing stacked common-mode filter 10.

[0204] In addition, in the stacked common-mode filter 100 according to an embodiment of the present invention, since the capacitor pattern forms an additional capacitance with the floating pattern 522, an additional depression can be formed in the common-mode attenuation characteristic, thereby expanding the attenuation band.

[0205] The first inductor pattern 532 and the second inductor pattern 542 form a single inductance. Opposite ends of the inductor patterns 532, 542 formed by the first inductor pattern 532 and the second inductor pattern 542 are respectively connected to the floating pattern 522 and the ground pattern 555, and a short-circuit circuit is formed between the floating pattern 522 and the ground pattern 555.

[0206] The inductance of the inductor patterns 532, 542 formed by the first inductor pattern 532 and the second inductor pattern 542 can be defined by the lengths of the first inductor pattern 532 and the second inductor pattern 542. The inductance of the inductor patterns 532, 542 formed by the first inductor pattern 532 and the second inductor pattern 542 is the dominant factor for adjusting and controlling the sub-resonant frequency of the stacked common-mode filter 100.

[0207] The main resonant frequency is determined by the capacitance formed between the first coil, the second coil, and the third coil. The sub-resonant frequency is determined by the capacitor patterns 511 to 516, the floating pattern 522, and the inductor patterns 532 and 542.

[0208] Here, compared with the capacitance formed between the capacitor patterns 511 to 516 and the floating pattern 522, the inductor patterns 532 and 542 have a relatively high inductance value, so they become the main factors for determining the sub-resonant frequency.

[0209] The inductor patterns 532, 542 have a numerical adjustment range that allows the sub-resonant frequency to be adjusted to various values within the same area, and since they have a smaller area compared to the capacitor patterns 511 to 516, the design flexibility can be improved. Compared with the inductor patterns 532, 542, the capacitor patterns 511 to 516 and the floating pattern 522 form a relatively small capacitance, thereby reducing the loss during signal transmission.

[0210] Thus, the inductor patterns 532, 542 are the dominant factors for determining the sub-resonant frequency, and the influence of parasitic inductance (parasitic L) that varies according to the mounting direction of the chip can be reduced, thereby preventing characteristic deviation due to the mounting direction.

[0211] See Figure 25 , assume that the first stacked common-mode filter 100a has a first inductor pattern 532 and a second inductor pattern 542 formed with a first length, the second stacked common-mode filter 100b has a first inductor pattern 532 and a second inductor pattern 542 formed with a second length, and the third stacked common-mode filter 100c has a first inductor pattern 532 and a second inductor pattern 542 formed with a third length. The first length is shorter than the second length, and the second length is shorter than the third length.

[0212] See Figure 26 , based on the common mode, the first stacked common-mode filter 100a (A), the second stacked common-mode filter 100b (B), and the third stacked common-mode filter 100c (C) form a first resonance frequency RF1 at approximately 2.45 GHz. The first resonance frequencies RF1 of the first stacked common-mode filter to the third stacked common-mode filters 100a (A) to 100c (C) can be regarded as the same within the error range.

[0213] On the other hand, the first stacked common-mode filter to the third stacked common-mode filters 100a to 100c form different second resonance frequencies RF2-1 to RF2-3 in the common mode. In other words, the first stacked common-mode filter 100a (see A) forms a second resonance frequency RF2-1 at approximately 4.8 GHz, the second stacked common-mode filter 100b (see B) forms a second resonance frequency RF2-2 at approximately 4.5 GHz, and the third stacked common-mode filter 100c (see C) forms a second resonance frequency RF2-3 at approximately 4.2 GHz.

[0214] That is, as the length of the inductor pattern (i.e., the first inductor pattern 532 and the second inductor pattern 542) increases, the inductance increases, and the second resonance frequency of the stacked common-mode filter 100 shifts to a lower frequency. As the length of the inductor pattern (i.e., the first inductor pattern 532 and the second inductor pattern 542) decreases, the inductance decreases, and the second resonance frequency of the stacked common-mode filter 100 shifts to a higher frequency.

[0215] See Figure 27 , based on the differential mode, the first stacked common-mode filter to the third stacked common-mode filters 100a to 100c generate cutoffs at approximately 7.1 GHz, 7.2 GHz, 7.37 GHz, and 7.53 GHz. The cutoff frequencies of the first stacked common-mode filter to the third stacked common-mode filters 100a to 100c can be regarded as the same within the error range.

[0216] It can be seen therefrom that the lengths of the inductor patterns 532 and 542 are the dominant factors for adjusting (controlling) the second resonance frequency of the stacked common-mode filter 100. By adjusting the length of the first inductor pattern 532 and / or the length of the second inductor pattern 542, the second resonance frequency characteristics of the stacked common-mode filter 100 can be changed.

[0217] In addition, in the stacked common-mode filter 100 according to an embodiment of the present invention, by placing (arranging) the third stacked body 500 including the inductor patterns 532 and 542 below the coil stacked body 400, a short-circuit circuit is formed, so that the second resonance frequency can be easily adjusted / controlled by adjusting the lengths of the inductor patterns 532 and 542.

[0218] See Figure 28 , the filter stacked body 110 may further include a first magnetic sheet 620 provided on the upper part of the first stacked body 200, and a second magnetic sheet 640 interposed between the second stacked body 300 and the third stacked body 500. Here, as an example, the first magnetic sheet 620 and the second magnetic sheet 640 are sheets formed of a magnetic material such as ferrite.

[0219] See Figure 29 , the filter stacked body 110 may further include a third magnetic sheet 660 provided below the third stacked body 500. Here, as an example, the third magnetic sheet 660 is a sheet formed of a magnetic material such as ferrite. The ferrite may include Ni-Zn or Mn-Zn.

[0220] The third magnetic sheet 660 can increase the parallel inductance caused by the inductor patterns 532 and 542. Adding the third magnetic sheet 660 to the lowermost part of the same multilayer structure enables the stacked common-mode filter 100 to have a lower sub-resonance frequency.

[0221] In the stacked common-mode filter 100 according to an embodiment of the present invention, the interval between the first resonance frequency and the second resonance frequency can be adjusted according to the presence or absence of the third magnetic sheet 660 provided at the lowermost part of the filter stacked body 110. Here, placing the third magnetic sheet 660 can reduce the interval (or result in a narrower interval) between the first resonance frequency and the second resonance frequency in the stacked common-mode filter 100.

[0222] See Figure 30, the first stacked common-mode filter 100a does not include the third magnetic sheet 660, and the inductor patterns 532 and 542 are formed to have a first length. The second stacked common-mode filter 100b does not include the third magnetic sheet 660, and the inductor patterns 532 and 542 are formed to have a second length longer than the first length. The third stacked common-mode filter 100c includes the third magnetic sheet 660, and the inductor patterns 532 and 542 are formed to have a first length. The fourth stacked common-mode filter 100 includes the third magnetic sheet 660, and the inductor patterns 532 and 542 are formed to have a second length longer than the first length.

[0223] See Figure 31 , the first stacked common-mode filter 100a has a first resonance frequency of about 2.35 GHz and a second resonance frequency of about 4.97 GHz. The second stacked common-mode filter 100b has a first resonance frequency of about 2.38 GHz and a second resonance frequency of about 4.37 GHz. The third stacked common-mode filter 100c has a first resonance frequency of about 2.45 GHz and a second resonance frequency of about 4.8 GHz. The fourth stacked common-mode filter 100 has a first resonance frequency of about 2.50 GHz and a second resonance frequency of about 4.21 GHz.

[0224] The interval G1 between the first resonance frequency and the second resonance frequency of the first stacked common-mode filter 100a is about 2.62 GHz. The interval G2 between the first resonance frequency and the second resonance frequency of the second stacked common-mode filter 100b is about 1.99 GHz. The interval G3 between the first resonance frequency and the second resonance frequency of the third stacked common-mode filter 100c is about 2.35 GHz. The interval G4 between the first resonance frequency and the second resonance frequency of the fourth stacked common-mode filter 100 is about 1.71 GHz.

[0225] When comparing the first stacked common-mode filter 100a and the third stacked common-mode filter 100c with the inductor patterns 532 and 542 of the same length, the interval G3 of the third stacked common-mode filter 100c including the third magnetic sheet 660 is reduced by about 0.27 GHz compared with the interval G1 of the first stacked common-mode filter 100a without the third magnetic sheet 660.

[0226] When comparing the second stacked common-mode filter 100b and the fourth stacked common-mode filter 100 with the inductor patterns 532 and 542 of the same length, the interval G4 of the fourth stacked common-mode filter 100 including the third magnetic sheet 660 is reduced by about 0.28 GHz compared with the interval G2 of the second stacked common-mode filter 100b without the third magnetic sheet 660.

[0227] Therefore, in the stacked common-mode filter 100 according to an embodiment of the present invention, the interval between the first resonance frequency and the second resonance frequency can be adjusted (controlled) by using the third magnetic sheet 660 provided at the lowermost part of the filter stack 110.

[0228] See Figure 32 , different from the conventional stacked common-mode filter having a structure in which a coil stack 12 and a capacitor stack 13 are stacked (i.e., an LC filter structure), the stacked common-mode filter 100 according to an embodiment of the present invention has a structure in which a third stack 500 in which capacitors and inductors are stacked is located below the coil stack 400 (i.e., an LPF filter structure). Therefore, compared with the conventional stacked common-mode filter 10, the stacked common-mode filter 100 according to an embodiment of the present invention has improved attenuation characteristics in common mode and insertion loss and cutoff characteristics in differential mode.

[0229] See Figure 33 , the conventional stacked common-mode filter (see C) forms three resonance frequencies, where the first resonance frequency is formed at about 2.5 GHz, the second resonance frequency is formed at about 5.2 GHz, and the third resonance frequency is formed at about 7.3 GHz.

[0230] The stacked common-mode filter 100 according to an embodiment of the present invention (see D) forms two resonance frequencies, where the first resonance frequency is formed at about 2.5 GHz and the second resonance frequency is formed at about 5.5 GHz.

[0231] It can be seen that the attenuation performance of the stacked common-mode filter 100 according to an embodiment of the present invention is only concentrated in the common-mode attenuation frequency band (i.e., the target frequency band), indicating that the attenuation characteristics in common mode are improved compared with the conventional stacked common-mode filter 10.

[0232] See Figure 34 , the stacked common-mode filter 100 according to an embodiment of the present invention (see E) has improved low-frequency cutoff characteristics and reduced ripple in differential mode compared with the conventional stacked common-mode filter (see F).

[0233] The above description is only an explanation of the technical idea of the present invention. Those skilled in the art can make various changes and deformations to the present invention without departing from the essential features of the present invention. Therefore, the embodiments of the present invention should not be construed as limiting the technical idea of the present invention, but as an explanation of the technical idea of the present invention. The technical idea of the present invention is not limited by the embodiments. The protection scope of the present invention should be interpreted based on the claims, and all technical ideas within the equivalent scope of the present invention should be understood to be covered within the scope of the claims of the present invention.

Claims

1. A stacked common mode filter, characterized in that, it includes: A first stack body provided with a first coil pattern, a second coil pattern, and a third coil pattern; and A second stack body provided with a fourth coil pattern, a fifth coil pattern, and a sixth coil pattern, and disposed below the first stack body to form a coil stack body together with the first stack body, The coil stack body includes: A first via conductor connected to the first coil pattern in the first stack body; A second via conductor connected to the sixth coil pattern in the second stack body; A third via conductor connected to the second coil pattern and the third coil pattern in the first stack body; and A fourth via conductor connected to the fourth coil pattern and the fifth coil pattern in the second stack body, In a top view of the coil stack body, the fourth via conductor is disposed at a position not overlapping with the first via conductor, the second via conductor, and the third via conductor.

2. The stacked common mode filter according to claim 1, characterized in that, The first stack body further includes a first terminal pattern and a second terminal pattern, The second stack body further includes a third terminal pattern and a fourth terminal pattern, The first via conductor connects the first coil pattern to the first terminal pattern in the first stack body, The second via conductor connects the sixth coil pattern to the fourth terminal pattern in the second stack body, The third via conductor connects the second coil pattern and the third coil pattern to the second terminal pattern in the first stack body, The fourth via conductor connects the fourth coil pattern and the fifth coil pattern to the third terminal pattern in the second stack body.

3. The stacked common mode filter according to claim 1, characterized in that, In a top view of the coil stack body, the third via conductor is disposed at a position not overlapping with the first via conductor and the second via conductor.

4. The stacked common mode filter according to claim 3, characterized in that, In a top view of the coil stack body, the first via conductor is disposed at a position not overlapping with the second via conductor.

5. The stacked common mode filter according to claim 3, characterized in that, In a top view of the coil stack body, the first via conductor is disposed at a position overlapping with the second via conductor.

6. The stacked common mode filter according to claim 1, characterized in that, In a vertical cross-sectional view of the coil stack body, the first via conductor is spaced apart from the second via conductor, the third via conductor and the fourth via conductor are spaced apart from each other between the first via conductor and the second via conductor, and the third via conductor is between the first via conductor and the fourth via conductor.

7. The stacked common mode filter according to claim 1, characterized in that, In a vertical cross-sectional view of the coil stack, the third via conductor is spaced apart from the fourth via conductor, the first via conductor and the second via conductor are spaced apart from each other between the third via conductor and the fourth via conductor, and the first via conductor is interposed between the second via conductor and the third via conductor.

8. The stacked common-mode filter according to claim 1, wherein, in a vertical cross-sectional view of the coil stack, the third via conductor is spaced apart from the fourth via conductor, the first via conductor and the second via conductor are interposed between the third via conductor and the fourth via conductor, and are arranged to overlap in a top view of the coil stack.

9. The stacked common-mode filter according to claim 1, wherein, it further includes a third stack provided with a floating pattern, an inductor pattern, a ground pattern, and a plurality of capacitor patterns, and is arranged below the second stack.

10. The stacked common-mode filter according to claim 9, wherein, the third stack includes: the plurality of capacitor patterns, which are arranged below the second stack; the floating pattern, which is arranged below the plurality of capacitor patterns and is configured to form an additional capacitance by overlapping with the plurality of capacitor patterns; the ground pattern, which is arranged below the floating pattern; and the inductor pattern, which is arranged between the floating pattern and the ground pattern, wherein, a first end of the inductor pattern is connected to the floating pattern, and a second end of the inductor pattern is connected to the ground pattern.

11. The stacked common-mode filter according to claim 9, wherein, the third stack includes: a ninth sheet; a plurality of capacitor patterns, which are located on a first surface of the ninth sheet and are spaced apart from each other; a tenth sheet, which is located below the ninth sheet; and a floating pattern, which is located on a first surface of the tenth sheet, forms a plurality of overlapping regions by overlapping with the plurality of capacitor patterns, and is configured to form an additional capacitance in the plurality of overlapping regions.

12. The stacked common-mode filter according to claim 11, wherein, the third stack further includes: the ground pattern, which is located below the tenth sheet; and the inductor pattern, which is interposed between the tenth sheet and the ground pattern and includes a first end connected to the floating pattern and a second end connected to the ground pattern.

13. The stacked common-mode filter according to claim 12, wherein, the third stack further includes: an eleventh sheet, which is interposed between the tenth sheet and the ground pattern; and a twelfth sheet, which is interposed between the eleventh sheet and the ground pattern, the inductor pattern includes: a first inductor pattern, which is located on a first surface of the eleventh sheet and includes a first end connected to the floating pattern through a via passing through the tenth sheet and a second end spaced apart from the first end; and A second inductor pattern, which is located on the first surface of the twelfth sheet, includes a first end connected to the ground pattern and a second end connected to the second end of the first inductor pattern through a via hole passing through the eleventh sheet.

14. The stacked common-mode filter according to claim 9, wherein, further comprising: a first magnetic sheet disposed above the first stack; and a second magnetic sheet interposed between the second stack and the third stack.

15. The stacked common-mode filter according to claim 14, wherein, further comprising a third magnetic sheet disposed below the third stack.

16. The stacked common-mode filter according to claim 9, wherein, the filter stack formed by stacking the first stack, the second stack, and the third stack has a first resonance frequency and a second resonance frequency higher than the first resonance frequency, as the length of the inductor pattern increases, the second resonance frequency shifts to a higher frequency.

17. The stacked common-mode filter according to claim 9, wherein, the filter stack formed by stacking the first stack, the second stack, and the third stack has a first resonance frequency and a second resonance frequency higher than the first resonance frequency, as the length of the inductor pattern decreases, the second resonance frequency shifts to a lower frequency.

18. The stacked common-mode filter according to claim 9, wherein, the filter stack formed by stacking the first stack, the second stack, and the third stack includes a first side surface, a second side surface opposite to the first side surface, a third side surface, and a fourth side surface opposite to the third side surface, the stacked common-mode filter further comprising: a first external electrode disposed on the first side surface and connected to the second ends of the first terminal pattern, the fourth terminal pattern, and the first capacitor pattern exposed on the first side surface; a second external electrode disposed on the first side surface and connected to the second ends of the third terminal pattern and the second capacitor pattern exposed on the first side surface; a third external electrode disposed on the first side surface and connected to the second ends of the second terminal pattern and the third capacitor pattern exposed on the first side surface; a fourth external electrode disposed on the second side surface and connected to the second ends of the first coil pattern, the sixth coil pattern, and the fourth capacitor pattern exposed on the second side surface; a fifth external electrode disposed on the second side surface and connected to the second ends of the second coil pattern, the third coil pattern, and the fifth capacitor pattern exposed on the second side surface; and a sixth external electrode disposed on the second side surface and connected to the second ends of the fourth coil pattern, the fifth coil pattern, and the sixth capacitor pattern exposed on the second side surface.

19. The stacked common-mode filter according to claim 18, wherein, it further comprises: a seventh external electrode disposed on the third side surface and connected to a first end of the ground pattern exposed on the third side surface; and an eighth external electrode disposed on the fourth side surface and connected to a twenty-first end of the ground pattern exposed on the fourth side surface.

20. The stacked common-mode filter according to claim 1, wherein, the coil stack is configured such that the first coil pattern, the second coil pattern, the third coil pattern, the fourth coil pattern, the fifth coil pattern, and the sixth coil pattern are stacked in sequence, the first coil pattern and the sixth coil pattern form a first coil, and the first coil forms a first channel, the second coil pattern and the third coil pattern are interposed between the first coil pattern and the sixth coil pattern and form a second coil, and the second coil forms a second channel, the fourth coil pattern and the fifth coil pattern are interposed between the third coil pattern and the sixth coil pattern and form a third coil, and the third coil forms a third channel.

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