KR20090100193A - Electromagnetic bandgap structure and printed circuit board - Google Patents

Abstract

PURPOSE: An electromagnetic band gap structure and a printed circuit board are provided to solve conductive noise without using a by-pass capacitor or a decoupling capacitor. CONSTITUTION: An electromagnetic band gap structure is composed of more than 3 conductive plates, a first stitching via(645), and a second stitching via(649). The first and second stitching via electrically connect one conductive plate with another conductive plate respectively with passing one flat above them.

Description

Electromagnetic bandgap structure and printed circuit board

The present invention relates to an electromagnetic bandgap structure, and more particularly, to an electromagnetic bandgap structure that blocks signal transmission of a specific frequency band and a printed circuit board including the same.

Recently introduced electronic devices and communication devices are becoming smaller, thinner and lighter. This is also closely related to recent trends in which mobility is important.

Such electronic devices and communication devices include a combination of various electronic circuits (analog circuit and digital circuit) for realizing the function / operation of the device. It is mounted on a printed circuit board (PCB) to perform the corresponding function. In this case, the electronic circuits mounted on the printed circuit board are mostly different from each other.

Accordingly, in a printed circuit board in which various electronic circuits are mounted in combination, the electromagnetic wave (EM wave) caused by the operating frequency of one electronic circuit and its harmonics is generally transferred to another electronic circuit to solve the noise problem. It is often generated. In this case, the transmitted noise may be largely classified into radiation noise and conduction noise.

Here, radiation noise (see reference numeral 155 of FIG. 1) can generally be easily reduced by enclosing the shielding cap on the electronic circuit, but conduction noise (see reference numeral 150 of FIG. 1). ) Is transmitted through a signal transmission path inside the substrate, so it is very difficult to find a method for noise reduction.

This will be described in more detail with reference to FIG. 1. 1 is a cross-sectional view of a printed circuit board equipped with two electronic circuits having different operating frequencies. Although a printed circuit board 100 having a four-layer structure is illustrated in FIG. 1, various modifications, such as a two-layer, six-layer, and eight-layer structure, are obvious.

Referring to FIG. 1, the printed circuit board 100 may include four metal layers 110-1, 110-2, 110-3, 110-4, abbreviated as 110 below, and interposed between each metal layer. Dielectric layers 120-1, 120-2, 120-3, hereinafter abbreviated as 120. On the top metal layer 110-1 of the printed circuit board 100, two electronic circuits 130 and 140, hereinafter referred to as the first electronic circuit 130 and the second electronic circuit 140, each having a different operating frequency, are included. It is mounted. Here, it is assumed that both the first electronic circuit 130 and the second electronic circuit 140 are digital circuits.

Here, assuming that the metal layer 110-2 is a ground layer and the metal layer 110-3 is a power layer, the first electronic circuit 130 and the second electronic circuit 140 Each ground pin of the ground pin is electrically connected to the metal layer 110-1, and each power pin is electrically connected to the metal layer 110-1. In addition, all ground layers and all power layers in the printed circuit board 100 are electrically connected to each other through vias. In FIG. 1, the via 160 connecting the metal layers 110-1, 110-3, and 110-4 is an example.

In this case, when the first electronic circuit 130 and the second electronic circuit 140 have different operating frequencies, for example, as shown in FIG. 1, the operating frequency of the first electronic circuit 130 and its harmonics. Conduction noise 150 caused by (harmonics) components are transmitted to the second electronic circuit 140 to interfere with the correct function / operation of the second electronic circuit 140.

These conduction noise problems are becoming increasingly difficult to solve as electronic devices become more complex and the operating frequencies of digital circuits increase. In particular, the bypass capacitor or decoupling capacitor method, which is a typical solution for conducting noise, has not been a suitable solution in an electronic device using a high frequency band.

In addition, the above methods can be applied to a network having a complicated wiring structure in which several types of electronic circuits are implemented on the same substrate, or a large number of active and passive components in a narrow area such as a system in package (SiP). Even when a high frequency band operating frequency is required, such as a board, there is a problem that a proper solution is not provided.

Therefore, an electromagnetic bandgap structure (EBG) has recently attracted attention as a solution for solving the above-described conductive noise. This is to shield the signal of a specific frequency band by placing an electromagnetic bandgap structure having a specific structure inside the printed circuit board.

Recently, as an electromagnetic bandgap structure, a form that has been studied is an electromagnetic bandgap structure having a mushroom type structure as shown in FIGS. 2A and 2B.

The electromagnetic bandgap structure 200 shown in FIGS. 2A and 2B includes a metal plate between the first metal layer 211 and the second metal layer 212 which functions as one of the ground layer and the power supply layer and the other layer, respectively. 232 is further formed, and the mushroom-like structure 230 connecting the first metal layer 211 and the metal plate 232 with the via 234 is repeatedly arranged. In this case, the first dielectric layer 221 is interposed between the first metal layer 211 and the metal plate 232, and the second dielectric layer 222 is interposed between the metal plate 232 and the second metal layer 222.

As such, when the mushroom structure 230 is further interposed between the first metal layer 211 and the second metal layer 212, a signal in a low frequency band as illustrated in FIGS. 2C and 2D (FIG. 2C) may be used. And reference signal (x) of FIG. 2d and a signal of a high frequency band (see reference numeral (y) of FIG. 2c and FIG. 2d) pass through, and a signal of a specific frequency band in the middle (FIG. 2c and Reference numeral (z) in FIG. 2D) can be shielded. As such, the reason why the electromagnetic bandgap structure 200 of FIGS. 2A and 2B perform a function such as a kind of band stop filter can be easily explained through the equivalent circuit diagram of FIG. 2C.

Referring to the equivalent circuit diagram of the mushroom-shaped electromagnetic bandgap structure 200 illustrated in FIG. 2C, a capacitance component C1 and an inductance component L1 are in series between the first metal layer 211 and the second metal layer 212. You are connected. Here, C1 is a capacitance component formed by the second metal layer 212, the second dielectric layer 222, and the metal plate 232, and L1 is formed in the via 234 located between the metal plate 232 and the first dielectric layer 211. It is an inductance component formed by By such L-C series connection, the mushroom-shaped electromagnetic bandgap structure 200 can perform a function as a kind of band-stop filter.

However, since the electromagnetic bandgap structure 200 having the mushroom structure as described above has only one inductance component and only one capacitance component to implement a function as a band stop filter, it is difficult to apply to various products. . This is because under the structure of FIGS. 2A and 2B there is a limit to the length of the via 234 that can be secured (ie corresponding to the inductance value), and the mushroom structure 230 is only present between two adjacent metal layers. Therefore, there is a limit in the capacitance value that can be secured.

In particular, in recent years, electronic devices and communication devices are becoming smaller, thinner, and lighter, and the bandgap frequency that is desired only by the mushroom-shaped electromagnetic bandgap structure 200 disposed in a narrow area in a printed circuit board. Getting the band is even more difficult. That is, the electromagnetic bandgap structure 200 having the mushroom-like structure shown in FIGS. 2A and 2B alone adjusts each bandgap frequency band according to the conditions and characteristics required for various applications, or within the bandgap frequency band. There is a limit in reducing conduction noise to below the intended noise level.

Therefore, research on the electromagnetic bandgap structure, which can not only shield or reduce conduction noise between the power supply layer and the ground layer, but also can be applied to various applications with different required bandgap frequency bands, is urgently needed. It is necessary.

Accordingly, the present invention provides an electromagnetic bandgap structure and a printed circuit board including the same that can shield conducted noise of a specific frequency band.

In addition, the present invention provides a printed circuit board that can solve the conductive noise problem by disposing an electromagnetic bandgap structure having a specific structure in the printed circuit board without using a bypass capacitor or a decoupling capacitor.

In addition, the present invention is more suitable for a multilayer printed circuit board, having flexibility of design, flexibility, as well as an electromagnetic bandgap structure capable of realizing two or more bandgap frequencies through a stitching via having a differential length and a printed circuit including the same. Provide a circuit board.

In addition, the present invention provides an electromagnetic bandgap structure and a printed circuit board including the same that can be applied to a variety of applications, electronic devices in general by implementing various bandgap frequency bands.

The present invention also provides an electromagnetic bandgap structure and a printed circuit board including the same, which can shield conducted noise of a high frequency band even when an operating frequency of a high frequency band is used as in a network board.

According to an aspect of the invention, three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And a second stitching via that electrically connects another conductive plate based on the one of the conductive plates of the conductive plates. Here, in the electromagnetic bandgap structure according to the embodiment of the present invention, a portion of the first stitching via passes through one plane in an upward direction based on the one conductive plate, and the one conductive plate and the Electrically connecting another conductive plate, and the second stitching via is partially connected to one of the conductive plates and the other through a plane in a downward direction with respect to the one conductive plate. It may be characterized by electrically connecting between one conductive plate.

Here, the first stitching via may include a first via having one end connected to one of the conductive plates, a second via having one end connected to the other conductive plate, and one plane in the upper direction. And a connection pattern having one end connected to the other end of the first via and the other end connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, when another conductive layer is further present between the conductive plate and the conductive layer, the first stitching via may pass through the clearance hole formed in the other conductive layer so as not to be electrically connected to the other conductive layer. .

Here, the second stitching via may include a first via having one end connected to the one conductive plate, a second via having one end connected to the another conductive plate, and one plane in the lower direction. And a connection pattern having one end connected to the other end of the first via and the other end connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, when another conductive layer is further present between the conductive plate and the conductive layer, the second stitching via may pass through the clearance hole formed in the other conductive layer so as not to be electrically connected to the other conductive layer. .

Here, the first stitching via and the second stitching via may have different lengths.

Here, the conductive plate may have a polygonal, circular or elliptical shape. Each of the conductive plates may have the same size, or the conductive plates may be divided into a plurality of groups having different sizes of the conductive plates. In addition, the conductive plates may be all located on the same plane.

According to another aspect of the invention, three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And a second stitching via that electrically connects another conductive plate based on the one of the conductive plates of the conductive plates. Here, the first stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the first stitching via via one plane in an upward or downward direction based on the one conductive plate. The second stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the second stitching via via another plane in the same direction as the portion of the first stitching via. It can be characterized by.

Here, the first stitching via may include a first via having one end connected to the one conductive plate, a second via having one end connected to the other conductive plate, and an upper or lower planar shape. Located at, the one end may include a connection pattern connected to the other end of the first via, the other end is connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, the second stitching via may include a first via having one end connected to the one conductive plate, a second via having one end connected to the another conductive plate, and the other planar surface in the same direction. Located at, the one end may include a connection pattern connected to the other end of the first via, the other end is connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, the conductive plate may have a polygonal, circular or elliptical shape. Each of the conductive plates may have the same size, or the conductive plates may be divided into a plurality of groups having different sizes of the conductive plates. In addition, the conductive plates may be all located on the same plane.

According to another aspect of the invention, three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And a second stitching via that electrically connects another conductive plate based on the one of the conductive plates of the conductive plates. Wherein a portion of the first stitching via and a portion of the second stitching via are electrically connected between the conductive plates via different positions on the same plane, the portion of the first stitching via and At least one conductive layer may be positioned between at least one of the portions of the second stitching via and the conductive plates.

The first stitching via may include a first via having one end connected to the one conductive plate, a second via having one end connected to the other conductive plate, and being positioned on the same plane. The second via may be connected to the other end of the first via, and the other end may include a connection pattern connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, the second stitching via is located on the same plane as a first via having one end connected to the one conductive plate, a second via having one end connected to the another conductive plate, One end may include a connection pattern connected to the other end of the first via and the other end connected to the other end of the second via.

Here, when the conductive layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern may be accommodated in the clearance hole formed in the conductive layer.

Here, a clearance hole may be formed in each of the at least one conductive layer corresponding to the position where the first stitching via and the second stitching via pass.

Here, the conductive plate may have a polygonal, circular or elliptical shape. Each of the conductive plates may have the same size, or the conductive plates may be divided into a plurality of groups having different sizes of the conductive plates. In addition, the conductive plates may be all located on the same plane.

According to the electromagnetic bandgap structure and the printed circuit board according to the present invention, there is an effect that can shield the conductive noise of a specific frequency band.

In addition, the present invention can solve the problem of conduction noise by disposing an electromagnetic bandgap structure having a specific structure in a printed circuit board without using a bypass capacitor or a decoupling capacitor.

In addition, the present invention has the effect of more than two bandgap frequency through a stitching via having a differential length, as well as having a more flexible design flexibility and degree of freedom to the multilayer printed circuit board.

In addition, the present invention has the effect that can be applied to a wide range of applications, electronic devices by implementing a variety of bandgap frequency bands.

In addition, the present invention has the effect of shielding the conducted noise of the high frequency band even when the operating frequency of the high frequency band is used as in the network board (network board).

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all modifications, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

Terms such as first and second may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that no other component exists in the middle.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art, and are not construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

Before describing each embodiment according to the present invention shown in FIGS. 5 through 8 in detail, a stitching via containing the basic principles of the present invention with reference to FIGS. 3A to 3C to aid in understanding the present invention. The electromagnetic bandgap structure including the first will be described first.

Although it will be easily confirmed through comparison with FIGS. 3A to 3C to be described later, the electromagnetic bandgap structure (that is, the electromagnetic bandgap structure shown in FIGS. 5 to 8) according to each embodiment of the present invention is a multilayer of three or more layers. An electromagnetic bandgap structure including a stitching via that can be applied to a multi-layer PCB is proposed. Accordingly, the electromagnetic bandgap structure according to each embodiment of the present invention is a two-layered electromagnetic bandgap structure including the stitching vias shown through FIGS. 3A to 3C and its basic principle (ie, shielding principle of a specific frequency band). ) Can be said to be expanded and deformed in a form more suitable for a multilayer printed circuit board and a form that can be more flexibly applied to a multilayer printed circuit board.

For this reason, almost all of the descriptions of FIGS. 3A to 3C and 4A to 4E to be described below (all except the two-layer structure) may be applied to the embodiments of the present invention as the same or similar principles. Of course.

In the present specification, in describing the electromagnetic bandgap structure of the present invention, a case where a metal layer and a metal plate are used will be described throughout, but it is made of an electrically conductive material other than metal. It will be apparent to those skilled in the art that the conductive layer and the conductive plate may be replaced with each other.

In addition, in all drawings attached to the present specification, all of the metal plates are shown to be stacked on the same plane, but the metal plates are not necessarily all stacked on the same plane. In this case, when all of the metal plates are not laminated on any one plane, since the structure has two or more layers, there may be a problem of increasing the number of layers. However, the case where the electromagnetic bandgap structure of the present invention is disposed in a multilayer printed circuit board Assuming, this will not work as a design disadvantage.

3A and 3B show an electromagnetic bandgap structure of a two-layer structure including stitching vias. 3B is a cross-sectional view when the electromagnetic bandgap structure of the two-layer structure including the stitching via shown in FIG. 3A is cut based on the line A-A '.

Here, for a clear contrast with the electromagnetic bandgap structure (ie, the electromagnetic bandgap structure of the structure shown in FIGS. 5 to 8) according to the embodiment of the present invention, the metal layer 310 is the first metal layer 310. For example, the metal plate 331 is the first metal plate 331, the metal plate 332 is the second metal plate 332, the metal plate 333 is the third metal plate 333, and the dielectric layer 320 is As the first dielectric layer 320, the stitching via 345 is referred to as the first stitching via 345, and the stitching via 340 is referred to as a second stitching via 349.

3A and 3B, the electromagnetic bandgap structure is electrically connected between a plurality of metal plates 331, 332, and 333, a first metal layer 310 positioned in a plane different from the metal plates, and any two metal plates of the plurality of metal plates. Stitching vias 345 and 349 that connect to each other. That is, the electromagnetic bandgap structure of FIGS. 3A and 3B has a two-layer structure having the first metal layer 310 as one layer and the plurality of metal plates 331, 332, and 333 as two layers. In this case, the first dielectric layer 320 is interposed between the first metal layer 310 and the plurality of metal plates 331, 332, and 333.

3A and 3B illustrate only components constituting the electromagnetic bandgap structure (that is, only parts constituting the two-layer electromagnetic bandgap structure including stitching vias) for convenience of illustration. . Accordingly, the first metal layer 310 and the metal plates 331, 332, and 333 illustrated in FIGS. 3A and 3B may be any two metal layers existing inside the multilayer printed circuit board. That is, it is apparent that other metal layers may be further present under the first metal layer 310, and other metal layers may be further present on the metal plates 331, 332, and 333.

For example, the electromagnetic bandgap structures shown in FIGS. 3A and 3B (which also applies to electromagnetic bandgap structures according to other embodiments shown in FIGS. 5-7) may be printed in multiple layers to shield conducted noise. The circuit board may be disposed between any two metal layers constituting a power layer and a ground layer, respectively. In addition, since the conduction noise problem is not necessarily a problem between the power supply layer and the ground layer, the electromagnetic bandgap structures shown through FIGS. 3A, 3B, and 5 to 7 may be used to form mutual layers in a multilayer printed circuit board. Of course, it may be disposed between any two ground layers or between any two power layers.

The first metal layer 310 may be any one metal layer present in the printed circuit board to transmit electrical signals. For example, the first metal layer 310 may be a metal layer serving as a power layer or a ground layer, or a metal layer serving as a signal layer constituting a signal line.

In this case, the first metal layer 310 is located in a plane different from the plurality of metal plates and is electrically separated from the plurality of metal plates. That is, the first metal layer 310 constitutes a different layer between the plurality of metal plates 331, 332, and 333 in electrical printed circuit boards. For example, when the first metal layer 310 is a power layer, the metal plates are electrically connected to the ground layer. When the first metal layer 310 is the ground layer, the metal plates are electrically connected to the power layer. Can be connected. Alternatively, when the first metal layer 310 is a signal layer, the metal plates may be electrically connected to a ground layer, and when the first metal layer 310 is a ground layer, the metal plates may be electrically connected to a signal layer. It is.

The plurality of metal plates 331, 332, and 333 are disposed on one plane above the first metal layer 310. At this time, any two metal plates are electrically connected through the stitching vias, and the plurality of metal plates are all electrically connected to each other by the respective stitching vias electrically connecting the two metal plates.

Here, FIG. 3A illustrates a form in which all of the metal plates are electrically connected to each other between four adjacent metal plates based on any one metal plate (one in FIG. 4A) through one stitching via. As long as it is possible to form a closed loop by being connected as one, the connection method between the metal plates through the stitching vias may be applied in any manner.

3A and 3B, only three metal plates having a square shape having the same area are illustrated for convenience of drawing, but various modifications are possible. This will be briefly described with reference to FIGS. 4A to 4E.

For example, the metal plate may have a variety of polygonal shapes, such as a rectangular shape as shown in Figure 4a, a triangular shape as shown in Figure 4b, in addition to hexagons, octagons, etc., there may be special limitations on the shape, such as a circular or oval shape. None of course. In addition, the metal plates may have the same size (area, thickness), respectively, as shown in FIGS. 4A, 4B, and 4E, but may be arranged in a plurality of groups having different sizes as shown in FIGS. 4C and 4D. .

In the case of FIG. 4C, a relatively large metal plate B and a relatively small metal plate C are alternately arranged, and each metal plate is electrically connected between neighboring metal plates through a stitching via. In the case of FIG. 4D, there is a relatively large sized large metal plate D and a relatively small sized small metal plates E1, E2, E3, E4. The small metal plates E1, E2, E3, and E4 are arranged in 2 ㅧ 2 and occupy a similar area as the large metal plate D as a whole. The small metal plates E1, E2, E3, and E4 are electrically connected to neighboring metal plates through four stitching vias, and the large metal plate D is neighboring small through eight stitching vias with eight neighboring small metal plates. It can be seen that it is electrically connected to the metal plates.

4A to 4E are views of the electromagnetic bandgap structures disposed / arranged inside the printed circuit board, respectively, when viewed from an upper side thereof, so that each metal plate in the drawing is one in the electromagnetic bandgap structure. Corresponds to a cell. That is, FIGS. 4A to 4D illustrate a case in which an electromagnetic band gap structure is repeatedly disposed on an entire surface of a substrate in a printed circuit board, and FIG. 4E illustrates an electromagnetic band only on a portion of a substrate surface in a printed circuit board. It can be said that the case where the gap structure is arranged in a band shape.

That is, although cells according to the electromagnetic bandgap structure may be densely arranged / arranged on the entire substrate surface of the printed circuit board as shown in FIGS. 4A to 4D, they may be arranged / arrayed only on some paths as shown in FIG. 4E. Of course. For example, in FIG. 4E, assuming that reference numeral 11 is a noise source point, and reference numeral 12 is a noise shielding destination, cells in one or more rows along only a noise propagation path between the noise source and the shielding destination are shown. Can be repeated. Alternatively, in FIG. 4E, assuming that reference numeral 21 is a noise source and reference numeral 22 is a noise shielding destination, the cells may be blocked (eg, shielded) across a noise transfer path between the noise source and the shielding destination. It can also be arranged in more than one column.

Here, the noise source and the noise shielding destination may be any two electronic circuits (see the first electronic circuit 130 and the second electronic circuit 140 in FIG. 1 described above) having different operating frequencies mounted on the printed circuit board. In particular, assuming a digital circuit), the printed circuit board may correspond to any one and the other of the positions where the two electronic circuits are to be mounted on the printed circuit board.

Stitching vias electrically connect between any two of the plurality of metal plates. In FIGS. 3A and 3B and FIGS. 4A to 4E, a method of electrically connecting two adjacent metal plates by stitching vias is employed, but two metal plates connected through any one stitching via must be positioned adjacently. It may not be between metal plates. In addition, although FIG. 3A illustrates a case in which another metal plate is connected through one stitching via based on one metal plate, it is necessary to place a special limit on the number of stitching vias connecting two metal plates. None is self-evident.

 However, all the descriptions below will focus on the case where two adjacent metal plates are connected through one stitching via.

In the stitching via electrically connecting any two metal plates, the metal vias do not connect the metal plates on the same plane but electrically connect adjacent metal plates via a plane different from the metal plates.

At this time, the stitching via is filled with a conductive material (for example, a conductive paste, etc.) in the form in which each of the first via and the second via is formed with a plating layer only on an inner wall thereof for electrical connection between the metal plates. It is configured to form, and the connection pattern should also be made of a conductive material such as metal will be apparent even if not specifically described.

In the first stitching via 345 electrically connecting the first metal plate 331 and the second metal plate 332, the first metal plate 331-> the first via 341-> the first metal layer 310. This is through the path of the connection pattern 343-> the second via 342-> the second metal plate 332 is located on the same plane. Similarly, when the second stitching via 349 electrically connects between the second metal plate 332 and the third metal plate 333, the second metal plate 332-> first via 346-> first metal layer. It is also through the path of the connection pattern 348-> second via 347-> third metal plate 333 which is coplanar with 310.

To this end, the first stitching via 345 may include a first via 341 having one end 341a connected to the first metal plate 331 and penetrating through the first dielectric layer 320, and one end 342a of the first stitching via 345. A second via 342 connected to the second metal plate 332 and penetrating through the first dielectric layer 320, and one end is connected to the other end 341b of the first via 341, and the other end is connected to the second via 342. The connection pattern 343 may be connected to the other end 342b of the 342 and positioned to pass through the same plane as the first metal layer 310.

In addition, the second stitching via 349 includes a first via 346 having one end 346a connected to the second metal plate 332 and penetrating through the first dielectric layer 320, and one end 347a having a third end. The second via 347 is formed to be connected to the metal plate 333 and penetrate the first dielectric layer 320. One end thereof is connected to the other end 346b of the first via 346, and the other end thereof is the second via 347. It may be configured to include a connection pattern 348 connected to the other end 347b of the ()) and positioned to pass through the same plane as the first metal layer 310.

That is, the first stitching via 345 and the second stitching via 349 electrically connect the first metal plate 331 and the second metal plate 332 and between the second metal plate 332 and the third metal plate 333, respectively. In this connection, a specific portion (ie, each of the connection patterns 343 and 348) is manufactured to pass through a plane other than the plane of the metal plates (ie, the first metal layer 310).

At this time, via lands are formed at one end and the other end of each of the non-sons 341, 342, 346, and 347 constituting the first stitching via 345 and the second stitching via 349. The via land is provided for the purpose of overcoming a positional error in the drilling process when the via is formed, and is formed larger than the diameter of the via. This can be easily confirmed through the fact that the area of one end and the other end of each via is shown larger than the diameter of the via in FIG. 3A.

In this case, the connection patterns 343 of the first stitching vias 345 and the connection patterns 348 of the second stitching vias 349 may each have clearance holes 351 and 352 formed in the first metal layer 310. Is accommodated in). This is because the first metal layer 310 and the metal plates constitute different layers with electrical signals, and each of the stitching vias is electrically separated between the first metal layer 310 and the metal plates electrically connected through the stitching vias. The connection patterns 343 and 348 are accommodated in the clearance holes 351 and 352 formed in the first metal layer 310.

As described above, the electromagnetic bandgap structure of the two-layer structure including the stitching via is based on any one of the two metal plates 331 and 332 based on any one cell 300 indicated by a dotted line in FIG. 3B. The metal plate 331-> stitching via 345 (i.e., the first via 341-> connecting pattern 343-> the second via 342 through a single stitching via 345). The other metal plate 332 is electrically connected in series. An equivalent circuit diagram of an electromagnetic bandgap structure having such a structure is shown in FIG. 3C.

When the equivalent circuit diagram of FIG. 3C is compared with the cell 300 of the dotted line of FIG. 3B, the inductance component L1 corresponds to the first via 341, and the inductance component L2 corresponds to the second via 342. The inductance component L3 corresponds to the connection pattern 343. C1 is a capacitance component by the metal plates 331 and 332 and any other dielectric and metal layer to be placed thereon, and C2 and C3 are the first metal layer 310 located on the side of the connection pattern 343 and Capacitance component by any other dielectric and metal layer to be located beneath it.

According to the equivalent circuit diagram as described above, the electromagnetic bandgap structure of FIGS. 3A and 3B performs a function as a band stop filter for shielding a signal of a specific frequency band. That is, as can be seen through the equivalent circuit diagram of FIG. 3C, the signal of the low frequency band (see reference numeral (x) of FIG. 3C) and the signal of the high frequency band (see reference numeral (y) of FIG. 3C) are electromagnetic band gaps. Signals in a particular frequency band in the middle of the structure (see references (z1), (z2), and (z3) in FIG. 3C) are shielded by the electromagnetic bandgap structure.

In this case, it should be noted that the electromagnetic bandgap structure of FIGS. 3A and 3B has a two-layer structure including stitching vias, and thus, a plurality of shielding paths by three inductance components and three capacitance components (FIG. Reference numerals (z1), (z2) and (z3) of 3c) may have a wider and more diverse bandgap frequency band. In contrast, the mushroom-shaped electromagnetic bandgap structure shown in FIGS. 2A and 2B described above has a single shielding path (i.e., a single path by one inductance component and one capacitance component), thus being very limited and narrow. It has no choice but to have a bandgap frequency band.

As such, through the equivalent circuit diagram of FIG. 3C, the electromagnetic bandgap structure of the two-layer structure including the stitching vias shown in FIGS. 3A and 3B is compared to the electromagnetic bandgap structure of the mushroom structure shown in FIGS. 2A and 2B. It is clearly demonstrated that the structure has a wider shielding range and better shielding efficiency.

In addition, according to the electromagnetic bandgap structure including the stitching via, the distance between the adjacent metal plates is electrically connected through the stitching via via a different plane, so that the length of the via is compared with the electromagnetic bandgap structure of the mushroom structure. There is an advantage that can be secured enough. In this case, since the length of the stitching via that can be secured is proportional to the inductance value that can be secured immediately, this serves as an advantage that sufficient adjustment of the inductance value can be achieved in the electromagnetic bandgap structure. In addition, since the metal plates are connected through stitching vias through different planes, a pattern for connecting the metal plates does not need to be formed in the same layer, so that the gaps between the metal plates can be narrowed. There is an advantage. As the spacing between the metal plates becomes narrower, the capacitance value present in the gap also increases proportionally, which also serves as an advantage that sufficient adjustment of the capacitance value in the electromagnetic bandgap structure is possible.

In the equivalent circuit diagram of FIG. 3C, each capacitance component may include a spaced gap between a metal plate and a metal layer, a spaced gap between neighboring metal plates, a dielectric constant of a dielectric material constituting a dielectric layer interposed between the metal layers or between the metal layer and the metal plate, the size, shape, and the like of the metal plate. The value can be changed by factors such as area and the like. The inductance component may also vary depending on factors such as the shape, length, diameter, thickness, width, and the like of each via and the connection pattern constituting the stitching via. Accordingly, if the above-described various factors are properly adjusted and designed, the structure shown in FIGS. 3A and 3B may be used to provide an electromagnetic bandgap structure (a kind of band rejection) for shielding or reducing a signal or noise of a specific frequency band. Function as a filter).

Therefore, a structure having the same structure as that of FIGS. 3A and 3B (of course, FIGS. 5 to 7 to be described later) on an entire substrate surface (see FIGS. 4A to 4D) or a part of the surface (see FIG. 4E) inside the printed circuit board. If the structure by the structure of the same) repeatedly arranged on the noise transmission path existing in the printed circuit board, it can function as an electromagnetic bandgap structure that can shield the signal transmission of a specific frequency band.

In the above, referring to FIGS. 3A and 3B, a two-layer structure having a first metal layer 310 as a lower layer and a plurality of metal plates 331, 332, and 333 as an upper layer, with a first dielectric layer 320 interposed therebetween. The electromagnetic bandgap structure including the stitching via having the center was examined.

However, the electromagnetic bandgap structure including the stitching via does not necessarily need to have the same shape and structure as in FIGS. 3A and 3B.

As an example, the electromagnetic bandgap structure including the stitching via does not necessarily need to have a metal layer (see 310 in FIGS. 3A and 3B) beneath the region where the stitching via and the metal plates are located. This is because the position where the connection pattern is to be formed among the stitching vias is not necessarily the portion where the metal layer exists.

That is, when any metal layer is present on the same plane corresponding to the position where the connection pattern is to be formed, the connection pattern is formed in the clearance hole formed in the metal layer on the same plane (see 310 in FIGS. 3A and 3B) (FIGS. 3A and 3B). 351, 352 of the present invention), but it is not necessarily the case as described above, and it may be assumed that there is no separate metal layer at the position where the connection pattern is to be formed (see FIG. 9B to be described later). There will be.

As another example, a two-layered electromagnetic bandgap structure including stitching vias does not necessarily have to have a stacked structure such as FIGS. 3A and 3B. That is, a two-layer electromagnetic bandgap structure including a stitching via has a lamination structure (ie, FIG. 2A and its lamination) including a stitching via penetrating metal plates as a lower layer, a metal layer as an upper layer, and a dielectric layer interposed therebetween. It can also take the form of an upside down structure.

In this case as well, the same noise shielding effect as described above can be expected.

Hereinafter, an electromagnetic bandgap structure and a printed circuit board including the same according to embodiments of the present invention will be described with reference to FIGS. 5 to 8, but may be overlapped with those of FIGS. 3A to 4E. Descriptions thereof will be omitted and descriptions will be given based on the features according to the embodiments of the present invention. Although this has been described above, the electromagnetic bandgap structure including the stitching vias shown in FIGS. 3A and 3B is in all technical aspects / principles except that it employs a two-layered structure of the invention of FIGS. This is because the same can be applied to each embodiment.

In addition, FIGS. 5 to 8 illustrate the electromagnetic bandgap structure of the present invention, among the plurality of metal layers present in the multilayer printed circuit board (see each reference numeral 100 of FIGS. 5 to 8), for the convenience of drawing. It is first clarified that a cross-sectional view showing a partial cross section of only a few metal layers directly associated with the portion is shown. Accordingly, it is apparent that at least one other metal layer may be further present at the top of the top layer or the bottom of the bottom layer when referring to the cross-sectional views shown in FIGS. 5 through 8.

In addition, in FIGS. 5 to 8, only three metal plates are illustrated for convenience of drawing and a clear understanding of the present invention, and then, between one another and another metal plate positioned adjacent to one metal plate. It is merely an example of the case of electrically connecting through one stitching via (that is, connecting between two adjacent cells based on one cell). That is, the electromagnetic bandgap structure according to each embodiment of the present invention may be disposed with various shapes, sizes, and arrangements on the entire substrate or a part of the substrate as described above with reference to FIGS. 4A to 4E. This will be clearly understood through the spirit of the present specification.

Therefore, hereinafter, each embodiment of the present invention will be focused on a case where two adjacent cells are connected based on one cell (refer to each of cells 500, 600, 700, and 800 indicated by dotted lines in FIGS. 5 to 8). An electromagnetic bandgap structure and a printed circuit board including the same will be described.

5 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to the first exemplary embodiment of the present invention. Also, FIG. 10A is a three-dimensional perspective view of the electromagnetic bandgap structure shown in FIG. 5.

The electromagnetic bandgap structure according to the first embodiment of the present invention includes a plurality of metal plates 531, 532, and 533 located on one plane between two metal layers 511 and 512 and two metal layers 511 and 512. ), And a first stitching via 545 electrically connecting between the other metal plate 531 based on one metal plate 532 of the plurality of metal plates 531, 532, and 533, and any one of the first and second stitching vias 545. A second stitching via 549 electrically connecting between another metal plate 533 based on the metal plate 532.

In this case, dielectric layers 521 and 522 may be interposed between the plurality of metal plates 531, 532, and 533 and the two metal layers 511 and 512, respectively.

Hereinafter, for convenience of description of the drawings and for convenience of contrast with the electromagnetic bandgap structures shown in FIGS. 3A and 3B, the metal layer 511 is referred to as the first metal layer 511, and the metal layer 512 is referred to as the second metal layer ( 512, the metal plate 531 is the first metal plate 531, the metal plate 532 is the second metal plate 532, the metal plate 533 is the third metal plate 533, the 521 The dielectric layer is referred to as the first dielectric layer 521 and the dielectric layer 522 is referred to as the second dielectric layer 522.

Each stitching via in the electromagnetic bandgap structures of FIGS. 5 and 10A is similar to the metal plates in electrically connecting any two metal plates, similar to each stitching via in the electromagnetic bandgap structures of FIGS. 3A and 3B. Rather than connecting on a plane, portions of the metal plates are electrically connected to each other through the plane and another plane.

However, in the case of the electromagnetic bandgap structure of FIGS. 5 and 10a, the first stitching via 545 and the second stitching via 549 connecting the two other metal plates adjacent to each other based on one metal plate are the metal plates. It is structurally different from the electromagnetic bandgap structure of FIGS. 3A and 3B in that it passes through two different planes located in different directions with respect to the planes 531, 532, and 533.

That is, unlike the electromagnetic bandgap structure of FIGS. 3A and 3B, the electromagnetic bandgap structure of FIGS. 5 and 10A has the first metal layer 511 as one layer and the metal plates 531, 532, and 533 as two layers. It has a three-layer structure in which the second metal layer 512 has three layers.

Accordingly, the first stitching via 545 has a second metal layer, which is another plane located in an upper direction thereof when a portion thereof (see reference numeral 543) is based on the plane in which the metal plates 531, 532, and 533 are stacked. Via the same plane as 512, the second metal plate 532 and the first metal plate 531 are electrically connected to each other. The second stitching via 549 is the first metal layer 511 which is another plane located in the lower direction when a portion thereof (see reference numeral 548) is based on the plane in which the metal plates 531, 532, and 533 are stacked. The second metal plate 532 and the third metal plate 533 are electrically connected to each other via the same plane.

To this end, the first stitching via 545 may include a first via 541 having one end connected to the first metal plate 531 and penetrating through the second dielectric layer 522, and one end having a second metal plate 532. A second via 542 connected to and formed through the second dielectric layer 522, one end of which is connected to the other end of the first via 541 and the other end of which is connected to the other end of the second via 542. The connection pattern 543 may be disposed to pass through the same plane as the second metal layer 512.

In addition, the second stitching via 549 has one end connected to the second metal plate 532 and a first via 546 formed through the first dielectric layer 521, and one end connected to the third metal plate 533. And a second via 547 formed through the first dielectric layer 521, one end of which is connected to the other end of the first via 546, the other end of which is connected to the other end of the second via 547, and the first metal layer. And a connection pattern 548 positioned to coplanar with 511.

Here, between the first metal layer 511 and the metal plates 531, 532, 533 or between the second metal layer 512 and the metal plates 531, 532, 533 are mutually different from each other in terms of electrical signals in the printed circuit board. Layers can be constructed. As described above with reference to FIGS. 3A to 3C, the first metal layer 511 and the second metal layer 512 function as a power layer or a signal layer in the printed circuit board, and the metal plates ( For example, 531, 532, and 533 function as a ground layer. Of course, the opposite can also be apparent. In this case, the connection pattern 543 of the first stitching via 545 and the connection pattern 548 of the second stitching via 549 may have a clearance hole 551 formed in the second metal layer 512 as shown in FIG. 5. ) And the clearance holes 552 formed in the first metal layer 511, respectively, to electrically separate between the metal plates 531, 532, and 533, the first metal layer 511, and the second metal layer 512. There is a need.

As described above, the first metal plate 531-> the first stitching via 545 (that is, between two metal stitching vias respectively connecting the two other adjacent metal plates with respect to one metal plate) (i.e., , The first via 541-> the connection pattern 543 located on the same plane as the second metal layer 512-> connected by the path of the second via 542)-> the second metal plate 532-> The second stitching via (ie, connected to the first via 546-> connecting pattern 548 located on the same plane as the first metal layer 511-> second via 547)-> third The metal plates 533 are connected in order.

In this case, the first stitching via 545 and the second stitching via 549 extending in different directions based on the metal plates 531, 532, and 533 respectively act as inductance components, and the metal plates 531, 532. , 533 and the first metal layer 511 disposed between the first dielectric layer 521 and the second metal layer 512 positioned between the metal plates 531, 532, 533 and the second dielectric layer 522. Each acts as a capacitance component. Therefore, a structure having a structure as shown in FIG. 5 on an entirety of a substrate surface (see FIGS. 4A to 4D) or a portion thereof (see FIG. 4E) inside the printed circuit board is disposed on the noise transfer path existing in the printed circuit board. Repeatedly arranged in, it can function as an electromagnetic bandgap structure that can shield the signal transmission of a specific frequency band.

10B, the first metal layer 511 and the second metal layer 512 are removed from the three-dimensional perspective view of FIG. 10A. As described above, in the multilayer printed circuit board, separate metal layers are not necessarily present in the lower part and the upper part adjacent to the area where the electromagnetic bandgap structure (ie, the metal plates and the stitching vias) according to the present invention will be disposed. It may show that it may. In the case of FIG. 10B, it will be apparent that a separate clearance hole does not need to be provided as shown in FIGS. 5 and 10A at the position where the connection pattern is to be formed among the stitching vias.

6 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to the second exemplary embodiment of the present invention. Also, FIG. 11A is a three-dimensional perspective view of the electromagnetic bandgap structure shown in FIG. 6.

The electromagnetic bandgap structure according to the second embodiment of the present invention includes a plurality of metal plates 631 and 632 positioned on one plane between any two metal layers 611 and 612 and the two metal layers 611 and 612. 633, a first stitching via 645 that electrically connects the other metal plate 631 based on any one of the plurality of metal plates 631, 632, and 633. A second stitching via 649 is electrically connected between another metal plate 633 based on one metal plate 632.

In the electromagnetic bandgap structure according to the second embodiment of the present invention, at least one of the two metal layers 611 and 612 is positioned between the metal plates 631, 632 and 633 with at least one other metal layer therebetween. . In FIG. 6, for example, the metal layer 612 has another metal layer between the metal plates 631, 632, and 633 with the metal layer 613.

In this case, dielectric layers 621, 622, and 623 may be interposed between the metal plates 631, 632, and 633 and the three metal layers 611, 612, and 613, respectively.

Hereinafter, for convenience of description of the drawings and for convenience of contrast with the electromagnetic bandgap structures shown in FIGS. 3A, 3B, and 5, the metal layer 611 is referred to as the first metal layer 611, and the metal layer 612 is referred to. As the second metal layer 612, the metal layer 613 as the third metal layer 613, the metal plate 631 as the first metal plate 631, the metal plate 632 as the second metal plate 632, A metal plate of 633 as a third metal plate 633, a dielectric layer of 621 as a first dielectric layer 621, a dielectric layer of 622 as a second dielectric layer 622, a dielectric layer of 623 as a third Named as dielectric layer 623.

6 and 11A, the first stitching via 645 is another plane positioned in its upper direction when a portion thereof (see reference numeral 643) is based on the plane in which the metal plates 631, 632, and 633 are stacked. Via the same plane as the second metal layer 612, the second metal plate 632 and the first metal plate 631 are electrically connected to each other. The second stitching via 649 is a first metal layer 611 which is another plane located in the lower direction when a portion thereof (see reference numeral 648) is based on the plane in which the metal plates 631, 632, and 633 are stacked. The second metal plate 632 and the third metal plate 633 are electrically connected to each other via the same plane.

As such, the electromagnetic bandgap structure according to the second embodiment of the present invention has the same principle as the electromagnetic bandgap structure according to the first embodiment described above, and includes a plurality of metal plates, and upper and lower parts thereof based on the metal plates. It consists of two stitching vias via which two metal layers, each located at the same plane, pass. However, in the second embodiment of the present invention, at least one of the two metal layers (ie, the second metal layer 612 in FIG. 6) is at least one other metal layer (ie, the third metal layer in FIG. 6). 613)), which is different from the electromagnetic bandgap structure according to the first embodiment of the present invention.

In contrast, in the first embodiment of the present invention, both the second metal layer 512 and the first metal layer 511 via the first stitching via 545 and the second stitching via 549 are formed of metal plates 531, 532, 533, metal layers located immediately above and below it.

Accordingly, in FIGS. 6 and 11A, one end of the first via 641 of the first stitching via 645 is connected to the first metal plate 631, and the third dielectric layer 623 and the third metal layer 613 are formed. ) And the second dielectric layer 622. One end of the second via 642 of the first stitching via 645 is connected to the second metal plate 632 and penetrates through the third dielectric layer 623, the third metal layer 613, and the second dielectric layer 622. Is formed. In addition, one end of the connection pattern 643 of the first stitching via 645 is connected to the other end of the first via 641, the other end thereof is connected to the other end of the second via 642, and the second metal layer 612. It is formed to pass through the same plane.

In addition, the second stitching via 649 may have a first via 646 having one end connected to the second metal plate 632 and penetrating through the first dielectric layer 621, and one end connected to the third metal plate 633. And a second via 647 formed through the first dielectric layer 621, one end of which is connected to the other end of the first via 646, the other end of which is connected to the other end of the second via 647, and the first metal layer. It may be configured to include a connection pattern 548 formed to pass through the same plane as 611.

In this case, the metal layers 611, 612, and 613 and the metal plates 631, 632, and 633 may constitute different layers with respect to electrical signals in the printed circuit board. For example, the first to third metal layers 611, 612, and 613 function as a power layer in a printed circuit board, and the metal plates 631, 632, and 633 function as a ground layer. That is what it is.

In this case, the connection pattern 643 of the first stitching via 645 and the connection pattern 648 of the second stitching via 649 have a clearance hole 651 formed in the second metal layer 612 as shown in FIG. 6. ) And the clearance holes 652 formed in the first metal layer 611, respectively, to electrically separate the metal plates 631, 632, and 633 from the first metal layer 611 and the second metal layer 612. There is a need.

6 and 11A, since the first via 641 and the second via 642 are formed through the third metal layer 613, respectively, in the first stitching via 645, the metal plates 631. The first via 641 and the second via 642 of the first stitching via 645 are connected to the third metal layer 613 due to the electrical separation between the first and second metal layers 632, 633 and 613. It is necessary to be formed to penetrate the clearance holes 653 and 654 formed respectively.

Here, the first stitching vias 645 and the second stitching vias 649, which are formed to extend with mutually different lengths in different directions with respect to the metal plates 631, 632, and 633, respectively, are different in proportion to their lengths. The first metal layer 611 and the metal plates 631, 632, 633 and the third dielectric layer which act as inductance components having a value and are positioned between the metal plates 631, 632, and 633 and the first dielectric layer 621. The third metal layer 613 positioned between 623 serves as a capacitance component, respectively.

6 and 11A, a third metal layer 613, which is another metal layer, is further interposed between the metal plates 631, 632, and 633 and the second metal layer 612. There is further a capacitance component by the second dielectric layer 622 and the second metal layer 612. The electromagnetic bandgap structure of FIG. 6 has the first metal layer 611 as one layer, the metal plates 631, 632, and 633 as two layers, the third metal layer 613 as three layers, and the second metal layer 612. This is because it has a four-layer structure having four layers). Of course, according to the electromagnetic bandgap structure of FIGS. 6 and 11A, it is obvious that the structure may have five or more layers in proportion to the number of metal layers to be interposed between the metal plates 631, 632, and 633. .

Therefore, a structure having a structure as shown in FIG. 6 on an entirety of a substrate surface (see FIGS. 4A to 4D) or a portion thereof (see FIG. 4E) inside the printed circuit board is disposed on the noise transfer path existing in the printed circuit board. Repeatedly arranged in, it can function as an electromagnetic bandgap structure that can shield the signal transmission of a specific frequency band.

In particular, according to the electromagnetic bandgap structures shown in FIGS. 6 and 11A, since the lengths between the first stitching vias 645 and the second stitching vias 649 are made different from each other, two bandgap frequencies having different bands are provided. (bandgap frequnecy) has a feature that can be obtained. This will be clearly seen through the frequency characteristic graph of FIG. 9 to be described later.

In addition, referring to FIG. 11B, the first to third metal layers 611, 612, and 613 are removed from the three-dimensional perspective view of FIG. 11A. In addition, as described above, in the multilayer printed circuit board, separate metal layers are necessarily present in the lower part and the upper part adjacent to the area where the electromagnetic bandgap structure (ie, the metal plates and the stitching vias) according to the present invention are to be disposed. It shows that you may not. This is not described through separate drawings, but the same is true for the case of FIGS. 7 and 8 to be described later.

7 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to the third exemplary embodiment of the present invention.

The electromagnetic bandgap structure according to the third embodiment of the present invention includes a plurality of metal plates 731, 732, and 733 located on one plane in the printed circuit board 100, and metal plates 731, 732, and 733. Two metal layers 711 and 712 positioned in different planes in the lower direction with respect to the stacked planes, and the other metal plate based on any one of the metal plates 732 of the metal plates 731, 732, and 733. A second stitching via 745 electrically connecting the first stitching via 745 electrically connecting the first metal stitching via 745 to another metal plate 733 based on one of the metal plates 732. It includes.

In this case, dielectric layers 721 and 722 may be interposed between the plurality of metal plates 731, 732, and 733 and any one metal layer 711, and between the two metal layers 711 and 712, respectively. have.

Hereinafter, for convenience of description of the drawings and for convenience of contrast with the electromagnetic bandgap structures shown in FIGS. 3A, 3B, 5 and 6, the metal layer 711 is referred to as the first metal layer 711, and the reference numeral 712 is used. The metal layer as the second metal layer 712, the metal plate 731 as the first metal plate 731, the metal plate 732 as the second metal plate 732, and the metal plate 733 as the third metal plate 733. The dielectric layer 721 is referred to as the first dielectric layer 721, and the dielectric layer 722 is referred to as the second dielectric layer 722.

In addition, in FIG. 7, the first metal layer 711 and the second metal layer 712 are illustrated as being positioned on different planes in the lower direction with respect to the metal plates 731, 732, and 733. Is nothing. That is, in the electromagnetic bandgap structure according to the third embodiment of the present invention, the first metal layer 711 and the second metal layer 712 are formed on different planes in the upper direction based on the metal plates 731, 732, and 733. It may be any two metal layers located at. The same applies to the electromagnetic bandgap structure according to the fourth embodiment of the present invention to be described later.

In addition, in FIG. 7, the first metal layer 711 is a metal layer directly adjacent to the metal plates 731, 732, and 733, and the second metal layer 712 is directly adjacent to the first metal layer 711. In this example, at least one further metal layer may be interposed between the first metal layer 711 and the metal plates 731, 732, and 733, and between the first metal layer 711 and the second metal layer 712. It can also be obvious. This also applies to the electromagnetic bandgap structure according to the fourth embodiment of the present invention to be described later.

Here, the electromagnetic bandgap structure illustrated in FIG. 7 includes three layers including the second metal layer 712 as one layer, the first metal layer 711 as two layers, and the metal plates 731, 732, and 733 as three layers. It has a structure. However, unlike the electromagnetic bandgap structure shown in FIG. 5, in the electromagnetic bandgap structure of FIG. 7, the first stitching via 745 and the second stitching via 749 are based on the metal plates 731, 732, and 733. The difference is that they are formed in one direction.

However, the electromagnetic bandgap structure shown in FIG. 7 is manufactured such that the two stitching vias have different lengths, similarly to the electromagnetic bandgap structure shown in FIG. 6 described above.

That is, in FIG. 7, the first stitching via 745 is another portion located closer to the lower direction when a portion thereof (see reference numeral 743) is based on the plane in which the metal plates 731, 732, and 733 are stacked. The second metal plate 732 and the first metal plate 731 are electrically connected to each other via the same plane as the first metal layer 711. The second stitching via 749 is another plane that is further away in the lower direction when a portion thereof (see reference numeral 748) is based on the plane in which the metal plates 731, 732, and 733 are stacked. Via the same plane as 712, the second metal plate 732 and the third metal plate 733 is electrically connected.

To this end, the first stitching via 745 may include a first via 741 having one end connected to the second metal plate 732 and penetrating through the first dielectric layer 721, and one end having the first metal plate 731. A second via 742 connected to and formed through the first dielectric layer 721, one end of which is connected to the other end of the first via 741, and the other end of which is connected to the other end of the second via 742. The connection pattern 743 may be formed to pass through the same plane as the metal layer 711.

One end of the first via 746 of the second stitching via 749 is connected to the second metal plate 732 and penetrates through the first dielectric layer 721, the first metal layer 711, and the second dielectric layer 722. Formed by One end of the second via 747 of the second stitching via 749 is connected to the third metal plate 733, and penetrates through the first dielectric layer 721, the first metal layer 711, and the second dielectric layer 722. Is formed. The connecting pattern 748 of the second stitching via 749 has one end connected to the other end of the first via 746 and the other end connected to the other end of the second via 747, and the second metal layer 712. It is formed to pass through the same plane.

In FIG. 7, the second stitching via 749 is formed between a total of three layers (meaning the second metal layer 712, the first metal layer 711, and the metal plates 732 and 733). In general, an interlayer connection method using vias in three or more layers includes a plated through hole (PTH) method (see FIG. 12A), a stack via method (see FIG. 12B), and a staggered via method (FIG. 12B). 12c), an o-ring via scheme (see FIG. 12d), and the like. That is, the second stitching via 749 of FIG. 7 is shown as the first via 746 and the second via 747 are both formed through a single process by the PTH method of FIG. 12A for convenience of illustration. Although this is the same for the stitching via of FIG. 8, various other schemes as described above may be used.

12B and the stacked via method of FIG. 12C include a plurality of blind via holes (BVHs) (see 746-1, 746-2, 747-1, and 747-2 of FIGS. 12B and 12C). Via lands (see 761 and 762 of FIGS. 12B and 12C) in the middle according to the stacking order are separately manufactured and electrically connected. In particular, in the case of the staggered via method of FIG. 12C, each BVH is formed to have a different central axis. In addition, in the case of the O-ring via method of FIG. 12D, the diameter of the via is narrowed toward the lower direction (see 746 ′ and 747 ′ of FIG. 12D). In addition, it is obvious that IVH (inner via hole) may be used to form the vias, and any method may be applicable to the present invention without particular limitation.

Here, the metal layers 711 and 712 and the metal plates 731, 732 and 733 may constitute different layers with respect to electrical signals in the printed circuit board. For example, the metal layers 711 and 712 function as a power layer in the printed circuit board, and the metal plates 731, 732 and 733 function as ground layers.

In this case, the connection pattern 743 of the first stitching via 745 and the connection pattern 748 of the second stitching via 749 are formed in the clearance hole 751 formed in the first metal layer 711 as shown in FIG. 7. ) And the clearance holes 752 formed in the second metal layer 712, respectively, to electrically separate between the metal plates 731, 732, and 733, the first metal layer 711, and the second metal layer 712. There is a need.

In addition, in FIG. 7, since the first via 746 and the second via 747 of the second stitching via 749 are also formed through the first metal layer 711, respectively, the first via 746 and the second via 747 are separately formed on the first metal layer 711. It needs to be formed to penetrate into the other clearance holes 753 and 754 formed.

As described above, in the electromagnetic bandgap structure according to the third embodiment of the present invention, the two metal layers 711 and 712 are different planes in one end direction based on a plane in which the metal plates 731, 732 and 733 are stacked. Because of the characteristic of being located on the stitching via (i.e., the second metal layer 712 in FIG. 7) located relatively far from the metal plates of the two stitching vias (i.e., in FIG. The two stitching vias 749 necessarily penetrate the metal layer (ie, the first metal layer 711 in FIG. 7) located at a relatively close distance. Therefore, a clearance hole (refer to reference numerals 753 and 754 in FIG. 7) needs to be formed separately in the metal layer located at a close distance corresponding to the position through which the stitching via via the long distance will pass.

In the third embodiment of the present invention, the first stitching vias 745 and the second stitching vias 749 each extending with different lengths in the same direction when referring to the metal plates 731, 732, and 733 are respectively A first metal layer 711 and a first metal layer 711 which act as inductance components having different values in proportion to the length, and are disposed between the metal plates 731, 732, and 733 and the first dielectric layer 721; The second dielectric layer 722 and the second metal layer 712 each act as a capacitance component.

Therefore, a structure having a structure as shown in FIG. 7 on an entirety of a substrate surface (see FIGS. 4A to 4D) or a portion thereof (see FIG. 4E) inside a printed circuit board is disposed on a noise transfer path existing in the printed circuit board. Repeatedly arranged in, it can function as an electromagnetic bandgap structure that can shield the signal transmission of a specific frequency band.

Here, since the lengths between the first stitching via 745 and the second stitching via 749 are made different from each other even when the electromagnetic bandgap structure of FIG. 7 is used, similarly to FIG. The bandgap frequnecy may be obtained.

8 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to a fourth exemplary embodiment of the present invention.

The electromagnetic bandgap structure according to the fourth embodiment of the present invention includes a plurality of metal plates 831, 832, and 833 located on one plane in the printed circuit board 100, and the metal plates 831, 832, and 833. ) Based on a metal layer 812 positioned between at least one other metal layer (in this case, reference numeral 811 in FIG. 8) and the metal plate 832 of any one of the metal plates 831, 832, and 833. A first stitching via 845 electrically connecting the other metal plate 831 to another metal plate 833 based on any one of the metal plates 832. Stitching vias 849.

In this case, dielectric layers 821 and 822 may be interposed between the plurality of metal plates 831, 832, and 833 and any one metal layer 811, and between the two metal layers 811 and 812. have.

Hereinafter, for convenience of description of the drawings and for convenience of contrast with the electromagnetic bandgap structures shown in FIGS. 3A, 3B, 5, 6, and 7, the metal layer 811 is referred to as the first metal layer 811. The metal layer 812 is the second metal layer 812, the metal plate 831 is the first metal plate 831, the metal plate 832 is the second metal plate 832, and the metal plate 833 is the third metal plate. In 833, the dielectric layer 821 is designated as the first dielectric layer 821, and the dielectric layer 822 is referred to as the second dielectric layer 822.

Here, the electromagnetic bandgap structure shown in FIG. 8 includes a third layer including the second metal layer 812 as one layer, the first metal layer 811 as two layers, and the metal plates 831, 832, and 833 as three layers. It has a structure similar to that of FIG. 7 in that it has a structure, and the stitching vias extend in only one direction with respect to the metal plates 831, 832, and 833.

However, in the case of FIG. 8, all of the stitching vias 845 and 849 are manufactured not to pass through the metal layer immediately adjacent to the metal plates 831, 832 and 833 (the first metal layer 811 of FIG. 8). Has a structure different from that of FIG.

That is, in FIG. 8, both the first stitching via 845 and the second stitching via 849 do not have their respective portions (see reference numerals 843 and 848) directly adjacent to the metal plates 831, 832, and 833. Via two different metal plates (ie, between the first metal plate 831 and the second metal plate 832) and the second through the metal layer (ie, the second metal layer 812) at different positions on the same plane. Between the metal plate 832 and the third metal plate 833).

To this end, one end of the first via 841 of the first stitching via 845 is connected to the first metal plate 831, and the first dielectric layer 821, the first metal layer 811, and the second dielectric layer 822 are formed. It is formed through). One end of the second via 812 of the first stitching via 845 is connected to the second metal plate 832, and penetrates through the first dielectric layer 821, the first metal layer 811, and the second dielectric layer 822. Is formed. The connection pattern 843 of the first stitching via 845 has one end connected to the other end of the first via 841, and the other end connected to the other end of the second via 842, and the second metal layer 812. It is formed to pass through the same plane.

Similarly, one end of the first via 846 of the second stitching via 849 is connected to the second metal plate 832, and the first dielectric layer 821, the first metal layer 811, and the second dielectric layer 822 are formed. It is formed through the through. The second via 847 of the second stitching via 849 has one end connected to the third metal plate 833, and passes through the first dielectric layer 821, the first metal layer 811, and the second dielectric layer 822. It is formed through. The connecting pattern 848 of the second stitching via 849 has one end connected to the other end of the first via 846 and the other end connected to the other end of the second via 847, and the second metal layer 812. It is formed to pass through the same plane.

In this case, the metal layers 811 and 812 and the metal plates 831, 832 and 833 may form different layers with respect to electrical signals in the printed circuit board. Accordingly, the connection pattern 843 of the first stitching via 845 and the connection pattern 848 of the second stitching via 849 may be formed at different positions of the second metal layer 812 as shown in FIG. 8. By being accommodated in the clearance holes 851 and 852, it is necessary to electrically separate between the metal plates 831, 832 and 833 and the second metal layer 712.

In addition, at this time, each of the vias 841, 842, 846, and 847 of the first stitching via 845 and the second stitching via 849 is inevitably formed through the first metal layer 811. Clearance holes 853, 854, 855, and 856 need to be formed in the first metal layer 811 to correspond to the positions where the respective vias 841, 842, 846, and 847 are to be penetrated.

Accordingly, also in the fourth embodiment of the present invention, the first stitching via 845 and the second stitching via 849 extending in the same direction when the metal plates 831, 832, and 833 are referred to each have an inductance component. And a first metal layer 811 and a first metal layer 811, a second dielectric layer 822, and a second metal layer disposed between the metal plates 831, 832, and 833 and the first dielectric layer 821. 812 each acts as a capacitance component.

Therefore, a structure having a structure as shown in FIG. 8 on an entirety of a substrate surface (see FIGS. 4A to 4D) or a part of the surface thereof (see FIG. 4E) in the printed circuit board is disposed on the noise transfer path existing in the printed circuit board. Repeatedly arranged in, it can function as an electromagnetic bandgap structure that can shield the signal transmission of a specific frequency band.

According to the electromagnetic bandgap structure according to each embodiment of the present invention described in detail above with reference to FIGS. 5 to 8, it is possible to implement a variety of bandgap frequency bands, thereby making it more versatile application, electronic devices There is an advantage that can be applied. This is because the electromagnetic bandgap structure according to each embodiment of the present invention has the following big features.

First, according to the electromagnetic bandgap structure of the present invention, there is an advantage that the length of the stitching vias connecting any two metal plates can be secured longer. This is because each stitching via in the electromagnetic bandgap structure of the present invention electrically connects two metal plates via another metal layer other than the adjacent metal layer, thereby ensuring a larger inductance value by the extended length. . Of course, by including other metal layers other than the adjacent metal layers, the electromagnetic bandgap structure of the present invention may further retain other electrical components (for example, capacitance components between metal layers or between metal plates and metal layers). It is obvious.

When adopting the electromagnetic bandgap structure of the present invention, this is an adjustable factor (i.e., various inductance components and capacitance components) compared to the existing electromagnetic bandgap structure (especially the mushroom structure shown in Figs. 2A and 2B). It means that can be obtained more variously. This means that the bandgap frequency band, which is the target frequency to be shielded, and its noise level can be more freely adjusted.

Secondly, the electromagnetic bandgap structure of the present invention has the advantage of having a form more suitable for application to a multi-layer PCB. The electromagnetic bandgap structure of the mushroom structure shown in FIGS. 2A and 2B (also the electromagnetic bandgap structure of the two-layer structure including the stitching vias shown in FIGS. 3A and 3B) is the capacitance within only two layers. Since the component and the inductance component must be secured, there is a difficulty in forming the structure more complicated and densely in the two layers. This is especially true when a large number of active devices and passive devices need to be applied to a narrow area such as a printed circuit board having a complex wiring structure in which various types of electronic circuits are implemented on the same substrate or a system in package (SiP).

On the other hand, in the electromagnetic bandgap structure of the present invention, since vias or connection patterns can be manufactured by dividing into multiple layers in a multilayer printed circuit board, design freedom and flexibility are increased accordingly.

Third, in the electromagnetic bandgap structure of the present invention, it is possible to form a stitching via having a differential length. Accordingly, the bandgap frequency band may be further expanded, and two or more through one electromagnetic bandgap structure. There is an advantage that the band gap frequency can also be secured. This can be easily understood through the frequency characteristic comparison graph of FIG. 9 to be described below.

FIG. 9 is a graph comparing frequency characteristics of the electromagnetic bandgap structure shown in FIG. 3B and the electromagnetic bandgap structure shown in FIG. 6.

FIG. 9 analyzes the frequency characteristics by scattering parameters in order to confirm whether the electromagnetic bandgap structure proposed in the present invention has a band blocking characteristic in a specific frequency band. Here, reference numeral 910 denotes the frequency characteristic of the electromagnetic bandgap structure of the two-layer structure including the stitching via illustrated in FIG. 3B, and reference numeral 920 includes the stitching via illustrated in FIG. 6 among the embodiments of the present invention. Frequency characteristics of a multilayer electromagnetic bandgap structure are shown.

Referring to FIG. 9, in the case of the electromagnetic bandgap structure of FIG. 3B, when the shielding rate is -50 dB, the bandgap frequency is about 1.5 to 4.7 GHz. In contrast, in the case of the electromagnetic bandgap structure illustrated in FIG. 6, it can be seen that the bandgap frequency is formed at about 0.75 to 4.7 GHz based on the same shielding rate (that is, -50 dB). That is, in the case of the electromagnetic bandgap structure of FIG. 6 according to the present invention, it can be seen that the noise shielding range is wider than that of the electromagnetic bandgap structure of FIG. 3b. Of course, it is easy to confirm that the noise level (ie, the shielding rate) is also lowered based on the same shielding frequency band.

In addition, in the case of the electromagnetic bandgap structure illustrated in FIG. 6, it can be seen that two bandgap frequency bands are formed based on a shielding rate of -75 dB (reference numeral 921 of FIG. 9). And 922). This is because the length between the two stitching vias is manufactured to have a differential length in the case of the electromagnetic bandgap structure of FIG. 6.

Here, the frequency characteristic graph of FIG. 9 is merely an example for explaining the difference in frequency characteristics between the electromagnetic bandgap structures of FIGS. 3B and 6 under similar conditions. Accordingly, the simulation results of FIG. 9 show that the spacing between metal plates or metal layers, the dielectric constant of each dielectric layer, the thickness of each dielectric layer, the change in capacitance values due to factors such as the size, shape, area of the metal plate, and stitching vias. It is apparent that the bandgap frequency and its shielding rate may be different depending on the change in inductance value by factors such as shape, length, thickness, width, cross-sectional area, and the like.

Although the above has been described with reference to a preferred embodiment of the present invention, those skilled in the art to which the present invention pertains without departing from the spirit and scope of the present invention as set forth in the claims below It will be readily understood that modifications and variations are possible.

1 is a cross-sectional view of a printed circuit board including two electronic circuits having different operating frequencies.

2A and 2B are perspective views of an electromagnetic bandgap structure having a mushroom structure as a way to solve the problem of conduction noise between electronic circuits mounted on a printed circuit board.

2C is an equivalent circuit diagram of the electromagnetic bandgap structure shown in FIG. 2B.

FIG. 2D is a graph showing the frequency characteristics of the electromagnetic bandgap structure shown in FIG. 2B.

3A is a perspective view illustrating an example of a two-layer electromagnetic bandgap structure including a stitching via as an electromagnetic bandgap structure according to the present invention;

FIG. 3B is a cross-sectional view when the electromagnetic bandgap structure of the two-layer structure including the stitching vias shown in FIG. 3A is cut based on the line AA ′. FIG.

3C is an equivalent circuit diagram of an electromagnetic bandgap structure of a two layer structure including the stitching vias shown in FIG. 3A.

4A is a plan view showing an arrangement structure of an electromagnetic bandgap structure including a stitching via having a rectangular metal plate.

4B is a plan view showing an arrangement structure of an electromagnetic bandgap structure including a stitching via having a triangular shaped metal plate.

4C and 4D are plan views showing an arrangement structure of an electromagnetic bandgap structure including a stitching via made of a plurality of groups of metal plates of different sizes.

4E illustrates a plan view of a band-like arrangement by an electromagnetic bandgap structure including stitching vias.

5 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to the first exemplary embodiment of the present invention.

6 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to a second exemplary embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to a third exemplary embodiment of the present invention. FIG.

8 is a cross-sectional view illustrating an electromagnetic bandgap structure having a multilayer structure including a stitching via and a printed circuit board including the same according to a fourth exemplary embodiment of the present invention.

FIG. 9 is a graph comparing the frequency characteristics of the electromagnetic bandgap structure shown in FIG. 3B and the electromagnetic bandgap structure shown in FIG. 6.

FIG. 10A is a perspective perspective view of the electromagnetic bandgap structure shown in FIG. 5. FIG.

Figure 10b is a view showing a form in which the metal layer of the three-dimensional perspective view shown in Figure 10a.

FIG. 11A is a perspective perspective view of the electromagnetic bandgap structure shown in FIG. 6. FIG.

Figure 11b is a view showing a form in which the metal layer of the three-dimensional perspective view shown in Figure 11a.

12A to 12D are diagrams for describing a via forming method for interlayer connection.

<Description of the symbols for the main parts of the drawings>

100: printed circuit board

300, 500, 600, 700, 800: electromagnetic bandgap structure

331, 531, 631, 731, 831: first metal plate

332, 532, 632, 732, 832: second metal plate

333, 533, 633, 733, 833: third metal plate

545, 645, 745, 845: First Stitching Via

549, 649, 749, 849: second stitching via

511, 611, 711, 811: first metal layer

512, 612, 712, 812: second metal layer

521, 621, 721, 821: first dielectric layer

522, 622, 722, 822: second dielectric layer

Claims (34)

Three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And A second stitching via electrically connecting between another conductive plate based on the conductive plate of any one of the conductive plates, The first stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the first stitching via via a plane in an upward direction based on the one conductive plate, The second stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the second stitching via via a plane in a downward direction based on the one conductive plate. Electromagnetic bandgap structure. The method of claim 1, The first stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the other conductive plate; An electromagnetic bandgap structure positioned on one plane in the upper direction, and including a connection pattern having one end connected to the other end of the first via and the other end connected to the other end of the second via. The method of claim 2, And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 3, If there is another conductive layer between the conductive plate and the conductive layer, the first stitching via penetrates through a clearance hole formed in the other conductive layer so as not to be electrically connected to the other conductive layer. Electromagnetic bandgap structure. The method of claim 1, The second stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the another conductive plate; An electromagnetic bandgap structure positioned on one plane in the downward direction and including a connection pattern having one end connected to the other end of the first via and the other end connected to the other end of the second via. The method of claim 5, And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 6, When there is another conductive layer between the conductive plate and the conductive layer, the second stitching via penetrates through a clearance hole formed in the other conductive layer so as not to be electrically connected to the other conductive layer. Electromagnetic bandgap structure. The method of claim 1, And the first stitching via and the second stitching via have different lengths. The method of claim 1, Electromagnetic bandgap structure, characterized in that the conductive plate has a polygonal, circular or oval shape. The method of claim 1, And the conductive plates are coplanar. The method of claim 1, The conductive band gap structure, characterized in that each conductive plate has the same size. The method of claim 1, And the conductive plates are divided into a plurality of groups having different sizes. Three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And A second stitching via electrically connecting between another conductive plate based on the conductive plate of any one of the conductive plates, The first stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the first stitching via via one plane in an upward or downward direction based on the one conductive plate, The second stitching via is electrically connected between the one conductive plate and the another conductive plate through a portion of the second stitching via via another plane in the same direction as the portion of the first stitching via. An electromagnetic bandgap structure. The method of claim 13, The first stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the other conductive plate; An electromagnetic bandgap structure positioned on one plane of the upper or lower direction, and including a connection pattern having one end connected to the other end of the first via and the other end connected to the other end of the second via. The method of claim 14, And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 13, The second stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the another conductive plate; An electromagnetic bandgap structure positioned on the other plane in the same direction, one end of which is connected to the other end of the first via and the other end of which is connected to the other end of the second via. The method of claim 16, And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 13, Electromagnetic bandgap structure, characterized in that the conductive plate has a polygonal, circular or oval shape. The method of claim 13, And the conductive plates are coplanar. The method of claim 13, The conductive band gap structure, characterized in that each conductive plate has the same size. The method of claim 13, And the conductive plates are divided into a plurality of groups having different sizes. Three or more conductive plates; A first stitching via electrically connecting between the other conductive plates based on one of the conductive plates; And A second stitching via electrically connecting between another conductive plate based on the conductive plate of any one of the conductive plates, A portion of the first stitching via and a portion of the second stitching via electrically connect between the conductive plates via different positions on the same plane, the portion of the first stitching via and the second At least one conductive layer is positioned between at least one of the portions of the stitching via and the conductive plates. The method of claim 22, The first stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the other conductive plate; And a connection pattern positioned on the same plane, one end of which is connected to the other end of the first via and the other end of which is connected to the other end of the second via. The method of claim 23, wherein And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 22, The second stitching via, A first via having one end connected to any one of the conductive plates, A second via having one end connected to the another conductive plate; And a connection pattern positioned on the same plane, one end of which is connected to the other end of the first via and the other end of which is connected to the other end of the second via. The method of claim 25, And a conductive layer on the same plane corresponding to a position where the connection pattern is to be formed, wherein the connection pattern is accommodated in a clearance hole formed in the conductive layer. The method of claim 22, And a clearance hole is formed in each of the at least one conductive layer corresponding to a position where the first stitching via and the second stitching via are to penetrate. The method of claim 22, Electromagnetic bandgap structure, characterized in that the conductive plate has a polygonal, circular or oval shape. The method of claim 22, And the conductive plates are coplanar. The method of claim 22, The conductive band gap structure, characterized in that each conductive plate has the same size. The method of claim 22, And the conductive plates are divided into a plurality of groups having different sizes. In a printed circuit board, A first stitching via that electrically connects three or more conductive plates, another conductive plate based on one of the conductive plates, and one of the conductive plates An electromagnetic bandgap structure including a second stitching via electrically connecting another conductive plate to each other is disposed between the noise transfer path between the noise source present on the printed circuit board and the noise shielding destination. The first stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the first stitching via via a plane in an upward direction based on the one conductive plate, The second stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the second stitching via via a plane in a downward direction based on the one conductive plate. Printed circuit board. In a printed circuit board, A first stitching via that electrically connects three or more conductive plates, another conductive plate based on one of the conductive plates, and one of the conductive plates An electromagnetic bandgap structure including a second stitching via electrically connecting another conductive plate to each other is disposed between a noise transfer path between a noise source present on the printed circuit board and a noise shielding destination. The first stitching via is electrically connected between the one conductive plate and the other conductive plate through a portion of the first stitching via via one plane in an upward or downward direction based on the one conductive plate, The second stitching via is electrically connected between the one conductive plate and the another conductive plate through a portion of the second stitching via via another plane in the same direction as the portion of the first stitching via. Printed circuit board characterized in that. In a printed circuit board, A first stitching via that electrically connects three or more conductive plates, another conductive plate based on one of the conductive plates, and one of the conductive plates An electromagnetic bandgap structure including a second stitching via electrically connecting another conductive plate to each other is disposed between a noise transfer path between a noise source present on the printed circuit board and a noise shielding destination. A portion of the first stitching via and a portion of the second stitching via electrically connect between the conductive plates via different positions on the same plane, the portion of the first stitching via and the second At least one conductive layer is positioned between at least one of the portions of the stitching via and the conductive plates.

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