KR20120044789A - Printed circuit board and electro application - Google Patents

Abstract

PURPOSE: A printed circuit board and electronic products are provided to shield noises of specific frequency bands by forming a structure in which low impedance regions and high impedance regions are alternately formed. CONSTITUTION: An electronic component(110) is arranged on a first substrate(100). An EBG structure covers at least part of the upper side of the first substrate in order to shield noises which are emitted from the first substrate. A second substrate(200) includes magnetic pillars. The EBG structure is inserted into the second substrate. The EBG structure is composed of metal layers, vias, and patterns. The second substrate shields noises emitted from the first substrate. A shield can is further prepared to cover at least part of the upper side of the first substrate, and the second substrate is combined with the shield can.

Description

Printed circuit boards and electronics {Printed circuit board and electro application}

The present invention relates to printed circuit boards and electronic products.

Electromagnetic interference (EMI) problem has been recognized as a noise problem due to the high operating frequency of electronic products. In particular, as the operating frequency of electronic products has been in the range of several tens of MHz to several GHz, these EMI problems have become more serious and a solution is urgently needed. In particular, research on the solution of the noise generated at the substrate edge (edge) of the EMI problem in the substrate has not been made, there is a limit to block the noise in the substrate entirely.

EMI noise refers to noise that causes noise problems caused by interference by transmitting an electromagnetic wave generated in one electronic circuit, an element, or a component to another circuit, element, or component. If the EMI noise is largely classified, it can be divided into radiation noise (see 10 and 30 in FIG. 1) and conduction noise (see 20 in FIG. 1).

In the case of EMI noise radiated from a substrate of an electronic product, it is generally common to solve by shielding an upper region of a substrate with a shield can (40 of FIG. 2) or attaching and absorbing an EMI field absorbent material. However, in the case of the shield can 40, new radiation noise (10 ′ in FIG. 2) is generated due to the antenna effect, which makes it difficult to shield all the EMI noise radiated to the outside, and in the case of the EMI field absorbing material, There is a limit to the frequency range that can be achieved, and effective shielding method is desperately needed.

In addition, in the case of the shield shield 40, various problems are often caused in the attachment, and there is a limitation on the thickness and also increases the weight of the lightweight electronic device. In the case of EMI field absorbers, it is difficult to develop a material capable of shielding EMI at various frequencies, and has a long development period and an increase in cost.

Therefore, there is an urgent need for a solution that can easily absorb various frequencies, has no antenna effect, is easy to apply, and economically mass-produced.

The present invention is to provide a printed circuit board and electronic products that can easily absorb a variety of frequencies, there is no antenna effect, easy to apply, and economically mass-produced.

According to an aspect of the invention, the first substrate on which the electronic component is mounted; And an EBG structure disposed inside the first substrate to cover at least a portion of an upper surface of the first substrate, and to shield noise emitted upward from the first substrate, wherein the magnetic filler is contained therein. There is provided a printed circuit board comprising a second substrate.

The second substrate may be attached to an upper surface of the first substrate through an adhesive, or may be coupled to a shield can covering at least a portion of the upper surface of the first substrate. In this case, the shield can may be grounded with the ground provided on the first substrate, and the EBG structure of the second substrate may be grounded with the shield can. In addition, an open hole may be formed in the shield can, and the second substrate may be coupled to only a portion of the shield can to cover the open hole. In this case, the opening hole may be formed on an upper surface of the electronic component.

The electronic component may be mounted on a surface of the first substrate, and the second substrate may be stacked on an upper surface of the first substrate by opening an area corresponding to the position of the electronic component.

The second substrate may include first and second conductors disposed on different planes from each other; A third conductor disposed on a plane different from the second conductor; It may include a stitching via that connects the first conductor and the third conductor via a plane on which the second conductor is disposed, and is electrically separated from the second conductor.

The second substrate may include a pair of fourth conductors spaced apart from each other on the same plane; A fifth conductor disposed on a plane different from the fourth conductor; A sixth conductor disposed in a plane between the fourth conductor and the fifth conductor; And a stitching via portion connecting the pair of fourth conductors to each other via the fifth conductor, and electrically separated from the sixth conductor.

In addition, the second substrate may have a shape bent to correspond to the shape of the first substrate.

According to another aspect of the present invention, there is provided an electronic product including a case and a first substrate provided inside the case, and inside the case facing the first substrate, noise radiated from the first substrate is applied. To shield, an electronic product is provided, characterized in that an EBG structure is inserted therein and a second substrate containing a magnetic filler is bonded.

The second substrate may include first and second conductors disposed on different planes from each other; A third conductor disposed on a plane different from the second conductor; It may include a stitching via that connects the first conductor and the third conductor via a plane on which the second conductor is disposed, and is electrically separated from the second conductor.

The second substrate may include a pair of fourth conductors spaced apart from each other on the same plane; A fifth conductor disposed on a plane different from the fourth conductor; A sixth conductor disposed in a plane between the fourth conductor and the fifth conductor; And a stitching via portion connecting the pair of fourth conductors to each other via the fifth conductor, and electrically separated from the sixth conductor.

The second substrate may have a shape bent to correspond to the shape of the first substrate.

According to a preferred embodiment of the present invention, it is possible to provide a printed circuit board and electronic products that can easily absorb various frequencies, there is no antenna effect, easy to apply, and economically mass-produced.

1 to 2 are cross-sectional views showing a printed circuit board according to the prior art.
3 is a cross-sectional view showing a printed circuit board according to an embodiment of the present invention.
4 is an enlarged cross-sectional view of the second substrate of FIG. 3.
5 to 7 are cross-sectional views showing printed circuit boards according to other embodiments of the present invention.
8 is a plan view illustrating a second substrate of a printed circuit board according to an exemplary embodiment of the present invention.
9 is a cross-sectional view showing an electronic product according to an embodiment of the present invention.
10 illustrates an embodiment of an EBG structure of the present invention.
FIG. 11 is an equivalent circuit diagram of the EBG structure shown in FIG. 10.
12-14 illustrate other embodiments of an EBG structure.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention is capable of various modifications and various embodiments, and specific embodiments are illustrated in the drawings and described in detail in the detailed description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention.

Hereinafter, preferred embodiments of a printed circuit board and an electronic product according to the present invention will be described in detail with reference to the accompanying drawings. In the following description with reference to the accompanying drawings, the same or corresponding components are given the same reference numerals. Duplicate description thereof will be omitted.

The printed circuit board according to the present exemplary embodiment covers the upper surface of the substrate on which the electronic component 110 is mounted by another substrate having an EBG structure inserted therein, thereby driving the electronic component 110 mounted on the substrate or driving the same. The present invention proposes a structure that can shield EMI noise radiated from a driving circuit. To this end, the printed circuit board according to the present embodiment includes a first substrate 100 on which the electronic component 110 is mounted, as shown in FIG. 3; And an EBG structure (280a, 280b, 280c of FIGS. 10 to 14) covering at least a portion of an upper surface of the first substrate 100 and shielding noise emitted upward from the first substrate 100. 280d), and includes a second substrate 200 containing a magnetic filler.

The second substrate 200 is a separate substrate from the first substrate 100 on which the electronic component 110 and the like are mounted. As shown in FIGS. 3 and 4, the EBG structures 280a, 280b, and 280c are formed therein. 280d) is inserted and contains a magnetic filler to shield the noise. Here, the EBG structure is composed of metal layers, vias, patterns, and the like provided in the substrate.

As described above, the printed circuit board according to the present exemplary embodiment does not use an expensive absorbent material in order to shield noise radiated upward from the first substrate 100, but only by adding the second substrate 200. Equivalent or better noise shielding can be achieved at significantly lower cost than using materials. In addition, in contrast to the prior art using only the shield can (40 in FIG. 2), the antenna effect does not occur, and the noise shielding effect can be improved significantly.

In addition, by including the magnetic filler in the second substrate 200, more specifically, the dielectric constituting the second substrate, it is possible to increase the permeability of the dielectric and thereby the frequency bandwidth of noise that the EBG structure can absorb. It will be able to widen. As a result, it is possible to absorb even the noise of the low frequency band, which has been difficult to absorb in the past, thereby realizing more substantial absorption of noise.

 Various embodiments of the EBG structure inserted into the second substrate 200 will be described later separately.

The second substrate 200 may be attached to the top surface of the first substrate 100 through the adhesive 290. More specifically, as shown in FIG. 3, when the electronic component 110 is mounted on the surface of the first substrate 100, the second substrate 200 is connected to the electronic component 110 through the adhesive 290. It may be attached to the top of the. The solder resist 270 may be formed on the opposite side to which the adhesive 290 is not applied so that various patterns constituting the EBG structure may be protected.

On the other hand, as shown in FIG. 5, when the upper surface of the first substrate 100 is covered by the shield can 300, the second substrate 200 is coupled to the shield can 300 so that the first substrate ( 100 may be covered.

In addition, when the shield can 300 is grounded with the ground (not shown) of the first substrate 100 through solder (not shown), the EBG structure of the second substrate 200 is grounded with the shield can 300. As a result, the EBG structure may be grounded with the ground (not shown) of the first substrate 100. Through this structure, the ground can be secured more widely, and the noise shielding effect can be further improved.

To this end, as shown in FIG. 6, a part of the EBG structure of the second substrate 200, that is, a metal layer (or pattern) is disposed to be in contact with the shield can 300, and then fixed such as an adhesive tape 205 or the like. A method of fixing the second substrate 200 to the shield can 300 may be used by means. In FIG. 6, the adhesive tape 205 covers the entire upper surface of the second substrate 200, but it may be applied only to a part according to design needs.

The second substrate 200 may be coupled to the lower surface or the entire upper surface of the shield can 300, but may be selectively coupled only to a specific portion. In this case, as shown in FIG. 6, an open hole 310 may be formed in the shield can 300, and the second substrate 200 may be coupled to cover the open hole 310. By selectively arranging the second substrate 200 only in a specific portion as described above, noise can be selectively shielded only for the portion desired by the user, and the excessive use of the second substrate 200 can be prevented, thereby reducing the cost. You can expect.

In consideration of the fact that noise is mainly emitted to the upper side of the electronic component, an opening may be formed in a portion of the shield can corresponding to the upper side of the electronic component, but the present invention is not limited thereto. Of course, the formation position, number, shape and the like can be variously changed.

On the other hand, when noise emitted by a driving circuit around the electronic component 110 is more important than noise radiated from the upper surface of the electronic component 110 mounted on the first substrate 100, the second substrate 200 may have an electron. The region corresponding to the position of the component 110 may have an open shape, and may be stacked on the upper surface of the first substrate 100. In this case, as shown in FIG. 7, the second substrate 200 is disposed between the electronic components 110, and the thickness of the printed circuit board may be prevented from increasing more than necessary. It becomes possible.

On the other hand, when the first substrate 100 has a shape other than a quadrangle, the second substrate 200 may also have a shape in which the outside thereof is bent correspondingly. That is, as shown in FIG. 8, a part of the second substrate 200 may have a semi-circle shape according to the outer shape of the first substrate 100, and in some cases, may have a shape such as a triangle.

The printed circuit board according to the above-described embodiment may be applied to various electronic products such as mobile phones and other mobile devices. In this case, as described above, the second substrate 200 of the electronic product 1000 is illustrated in FIG. 9. It may be coupled to the inside of the case 400. In this case, there is an advantage in that the second substrate 200 into which the EBG structure is inserted is simply located in the case 400 of the electronic product, without the need of additionally providing a separate shield can.

Hereinafter, various embodiments of the EBG structure inserted into the second substrate 200 will be described.

First, an EBG of stitching via type is shown in FIG. 10. The bandgap structure 280a according to the present embodiment may include a first conductor 230a-1 and a second conductor 210a disposed on different planes; A third conductor 230a-2 disposed on a plane different from the second conductor 210a; Stitching is connected to the first conductor 230a-1 and the third conductor 230a-2 via a plane on which the second conductor 210a is disposed, and is electrically separated from the second conductor 210a. The via portion 240a is included.

The principle illustrated in FIG. 10 may function as an electromagnetic bandgap structure that shields a signal of a specific frequency band as follows. A dielectric layer 220a is interposed between the second conductor 210a and the first and third conductors 230a-1 and 230a-2, whereby the second conductor 210a and the first and third conductors are interposed therebetween. There is a capacitance component formed between the sieves 230a-1 and 230a-2 and between the neighboring first conductor 230a-1 and the third conductor 230a-2. In addition, the two vias 230a-1 and 230a-2 which are adjacent to each other by the stitching via part 240a pass through the first via 241a-> the connection pattern 243a-> the second via 242a. Inductance components also exist. At this time, the capacitance component is spaced apart between the second conductor 210a and the first and third conductors 230a-1 and 230a-2 and between two neighboring conductors 230a-1 and 230a-2. The value is changed by factors such as the dielectric constant of the dielectric material constituting the dielectric layer 220a, the size, shape, area, and the like of the conductor. The inductance component also varies depending on factors such as the shape, length, thickness, width, cross-sectional area, etc. of the first via 241a, the second via 242a, and the connection pattern 243a. Accordingly, if the above-described various factors are properly adjusted and designed, the structure shown in FIG. 10 may be used in order to remove or shield a specific signal or specific noise of a desired frequency band (a kind of band rejection filter). Function as a function). This can be easily understood through the equivalent circuit diagram of FIG.

11, the inductance component L1 corresponds to the first via 241a, the inductance component L2 corresponds to the second via 242a, and the inductance. The component L3 corresponds to the connection pattern 243a. C1 is a capacitance component by the first and third conductors 230a-1 and 230a-2 and any other dielectric layer and second conductor 210a to be positioned thereon, and C2 and C3 are connection patterns 243a. Is a capacitance component by the second conductor 210a coplanar to it, and any other dielectric layer and second conductor 210a to be positioned thereunder.

According to the equivalent circuit diagram as described above, the electromagnetic bandgap structure 280a of FIG. 10 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. 11, the signals of the low frequency band (see reference numeral (x) of FIG. 11) and the signals of the high frequency band (see reference numeral (y) of FIG. 11) are electromagnetic band gaps. The signal in a specific frequency band in the middle of the structure (see reference numerals (z1), (z2), and (z3) in FIG. 11) is shielded by the electromagnetic bandgap structure.

12 shows a structure of another embodiment EBG structure 280b. As shown in FIG. 12, the EBG structure according to the present embodiment includes a pair of fourth conductors 210b spaced apart from each other on the same plane; A fifth conductor 230b disposed on a plane different from the fourth conductor 210b; A sixth conductor 220b disposed in a plane between the fourth conductor 210b and the fifth conductor 230b; And a stitching via portion 240b that connects the pair of fourth conductors 210b to each other via the fifth conductor 230b and is electrically separated from the sixth conductor 220b.

In the case of the EBG structure shown in FIG. 12, a variation of the EBG structure 280a shown in FIG. 10 may be used as the fifth conductor 230b as well as between the fourth conductor 210b and the sixth conductor 220b. ) And the capacitance component is further present between the sixth conductor 220b and the length of the via 240b connecting the fourth conductor 210b and the fifth conductor 230b to be longer. Therefore, the value of the inductance component can be sufficiently secured. This makes it possible to improve the shielding efficiency of signal transmission in a specific frequency band.

In another embodiment, a mushroom type EBG 280c (EBG) is shown in FIG. 13. The mushroom EBG 280c is, for example, an EBG cell having a mushroom shape between two metal layers 210c and 220c that will function as a power layer and a ground layer. 230c) has a structure in which a plurality of inserts. 9 illustrates only four EBG cells 230c for the convenience of illustration.

Referring to FIG. 13, the mushroom EBG 280c further includes a metal plate 231c between the first metal layer 210c and the second metal layer 220c which serve as one of the ground layer and the power supply layer, and the other. And a mushroom-like structure 230c, which is formed between the first metal layer 210c and the metal plate 231c with vias 232c, is repeatedly formed. In this case, the first dielectric layer 215c is interposed between the first metal layer 210c and the metal plate 231c, and the second dielectric layer 225c is interposed between the metal plate 231c and the second metal layer 220c.

The mushroom EBG 280c includes a capacitance component formed by the second metal layer 220c, the second dielectric layer 225c, and the metal plate 231c, and passes through the first dielectric layer 215c and the first metal layer 210c. The inductance component formed by the vias 232c connecting the metal plates 231c has an LC series connection between the first metal layer 210c and the second metal layer 220c, thereby forming a kind of band stop filter. It will function as.

In another embodiment, a coplanar EBG (coplanar EBG) is shown in FIG. 14. The coplanar EBG (coplanar EBG) has a structure in which a plurality of EBG cells (see reference numeral 220d in FIG. 14) of a specific pattern are repeatedly arranged through one of the metal layers which will function as a power supply layer or a ground layer. FIG. 14 also shows a total of four EBG cells 220d for convenience of illustration.

Referring to FIG. 14, the coplanar EBG 280d may include a plurality of metal plates 221d positioned in a plane different from any one metal layer 210d through a specific portion (the corner end of each metal plate in FIG. 14). (metal branch, 222d) has a form that is bridged to each other (bridge).

At this time, the metal plates 221d having a large area constitute a low impedance area, and the metal branches 222d having a small area constitute a high impedance area. Therefore, the coplanar EBG 280d has a structure in which the low impedance region and the high impedance region are alternately formed to perform a function as a band reject filter that can shield noise of a specific frequency band.

Such a coplanar EBG structure 280d has an advantage that an electromagnetic bandgap structure can be configured with only two layers.

In the above description, four types 280a, 280b, 280c, and 280d are described as examples of the EBG structure inserted into the second substrate 200. However, other EBG structures having various modified structures may also be inserted into the second substrate 200. Of course.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. It will be understood that the invention may be varied and varied without departing from the scope of the invention.

Many embodiments other than the above-described embodiments are within the scope of the claims of the present invention.

100: first substrate
200: second substrate
280a, 280b, 280c, 280d: EBG structure

Claims (14)

A first substrate on which the electronic component is mounted; And
An EBG structure inserted therein to cover at least a portion of an upper surface of the first substrate and to shield noise radiated upwardly from the first substrate, and including a magnetic filler Printed circuit board comprising a substrate.
The method of claim 1,
The second substrate is a printed circuit board, characterized in that attached to the upper surface of the first substrate through an adhesive.
The method of claim 1,
Further comprising a shield can covering at least a portion of the upper surface of the first substrate,
The second substrate is a printed circuit board, characterized in that coupled to the shield can.
The method of claim 3,
The shield can is grounded to ground provided on the first substrate,
The EBG structure of the second substrate is grounded with the shield can.
The method of claim 3,
An opening is formed in the shield can,
And the second substrate is coupled to only a portion of the shield can to cover the opening.
The method of claim 5,
The opening is a printed circuit board, characterized in that formed on the upper surface of the electronic component.
The method of claim 1,
The electronic component is mounted on the surface of the first substrate,
The second substrate is a printed circuit board, characterized in that the region corresponding to the position of the electronic component is open, stacked on the upper surface of the first substrate.
The method of claim 1,
The second substrate,
First and second conductors disposed on different planes from each other;
A third conductor disposed on a plane different from the second conductor;
And a stitching via configured to connect the first conductor and the third conductor via a plane on which the second conductor is disposed, and to be electrically separated from the second conductor.
The method of claim 1,
The second substrate,
A pair of fourth conductors spaced apart from each other on the same plane;
A fifth conductor disposed on a plane different from the fourth conductor;
A sixth conductor disposed in a plane between the fourth conductor and the fifth conductor; And
And a stitching via configured to connect the pair of fourth conductors to each other via the fifth conductor, and to be electrically separated from the sixth conductor.
The method of claim 1,
The second substrate is a printed circuit board, characterized in that having a shape bent corresponding to the shape of the first substrate.
An electronic product comprising a case and a first substrate provided inside the case.
An electronic product, comprising: a second substrate having an magnetic filler embedded therein and having an EBG structure inserted therein to shield noise emitted from the first substrate, inside the case facing the first substrate; .
The method of claim 11,
The second substrate,
First and second conductors disposed on different planes from each other;
A third conductor disposed on a plane different from the second conductor;
And a stitching via configured to connect the first conductor and the third conductor via a plane on which the second conductor is disposed, and to be electrically separated from the second conductor.
The method of claim 11,
The second substrate,
A pair of fourth conductors spaced apart from each other on the same plane;
A fifth conductor disposed on a plane different from the fourth conductor;
A sixth conductor disposed in a plane between the fourth conductor and the fifth conductor; And
And a stitching via portion connecting the pair of fourth conductors to each other via the fifth conductor and electrically separated from the sixth conductor.
The method of claim 11,
And the second substrate has a shape bent to correspond to the shape of the first substrate.

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