KR100560932B1 - Printed circuit board having three-dimensional patterned wave guides - Google Patents

Abstract

The present invention relates to a printed circuit board in which a waveguide for transmitting high frequency is directly formed therein. In the related art, a separate waveguide made of a microstrip or stripline is used as a transmission line on a printed circuit board (PCB). On the other hand, since the waveguide is formed directly inside the printed circuit board, it can be usefully applied when it is difficult to use a waveguide separately configured in a mobile communication terminal having a small size and a high density of circuits, and at the same time a high frequency transmission line of the waveguide Completely shielding the top, bottom, left and right to eliminate mutual interference with other surrounding signals and dramatically reduce the transmission loss, so that the printed circuit is equipped with a three-dimensional waveguide inside the circuit to dramatically improve the characteristics of the circuit. It relates to a substrate.

In the present invention, the PCB inner layer, the PCB upper layer laminated on the upper part of the PCB inner layer, the PCC lower layer laminated on the lower part of the PCB inner layer, and the PCB upper layer laminated or not interposed through another PCB layer above. A multilayer printed circuit board having at least four layers including a PCB surface layer on which an electrical and electronic device is mounted is stacked on the upper surface thereof, wherein a high frequency transmission line is formed on the inner layer of the PCB, A ground layer is formed on a surface, and a ground layer corresponding to the ground layer of the upper portion of the PCB is formed on the surface of the lower portion of the PCB, and the upper portion of the upper portion of the PCB, the inner portion of the PCB, and the PCB are maintained at a predetermined distance. The through groove having a predetermined width passing through the lower layer in the vertical direction is transmitted. It is formed continuously along the length direction of the phosphor, and a plating layer having a predetermined thickness electrically connecting the ground layer of the upper layer of the PCB and the ground layer of the lower layer of the PCB is formed on both surfaces of the through groove, and at a predetermined interval between the two plating layers. By the addition, a three-dimensional pattern is formed inside the printed circuit board, in which a cross-sectional rectangular waveguide is directly formed in the printed circuit board, the upper and lower ground layers of which are shielded by the upper and lower ground layers, both plating layers, and the space part. A printed circuit board having a waveguide of is provided.

Waveguide, printed circuit board, PCB, solid pattern, high frequency, transmission, shielding, impedance

Description

Printed circuit board having three-dimensional patterned wave guides

1 is a perspective view showing the structure of a conventional microstrip waveguide

Figure 2 is a perspective view showing the structure of a conventional strip line waveguide

3 is a cross-sectional view showing a printed circuit board having a waveguide having a three-dimensional pattern therein according to the present invention.

4 is a perspective view illustrating main parts of the waveguide part separately in FIG. 3;

5 shows an ideal square coaxial waveguide

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

100: waveguide

110 to 160: PCB first layer to PCB sixth layer
112, 142, 152, 162: signal lines 122, 142: ground layer

200: high frequency transmission line 210: through groove

220: plating layer

The present invention relates to a printed circuit board in which a waveguide for transmitting high frequency is directly formed therein. More specifically, a conventional waveguide made of a microstrip or stripline is conventionally transmitted on a printed circuit board (PCB). Unlike that used as a line, since the waveguide is formed directly inside the printed circuit board, it can be usefully applied when it is difficult to use a waveguide separately configured in a mobile communication terminal having a small size and a high density of circuits. By shielding the top, bottom, left and right of the high frequency transmission line completely, it eliminates mutual interference with other surrounding signals and dramatically lowers the transmission loss. It relates to a printed circuit board provided.

Waveguides generally include the interior of wireless transmitters and receivers, such as communication satellites, broadcast satellites, and antenna signal circuits, or the inside of mobile communication terminals (cellular phones, PCS phones, PDAs (Poratble Digital Asistant) terminals). It is widely used as a transmission line for transmitting a high frequency signal in a (local) signal circuit.

Various conventional examples of waveguides for transmitting high frequency signals as described above are illustrated in the accompanying drawings, FIGS. 1 and 2.

First, the waveguide 20 shown in FIG. 1 represents a conventional Microstrip waveguide, which is one surface of the insulator substrate 26 as ground 22 and the surface layer of the conductor. The transmission line 24 has a form.

The microstrip waveguide includes a distance H between two layers, a width W of the transmission line 24, a thickness T of the transmission line 24, a dielectric constant Er of the insulator substrate 26 between the layers, and the like. It is calculated to achieve the best impedance matching by calculating.

In the conventional microstrip waveguide as described above, the signal transmitted along the transmission line 24 has a high signal level, but is exposed to the outside, so that shielding in the upper direction, left and right directions is incomplete, so that the signals in other surroundings are different. The disadvantage is that it is easy to affect the line and the transmission loss is large.

Particularly, in a mobile communication terminal which is aimed at a light and small size and has a large number of parts, the upper and left and right radiation waves emitted from the exposed transmission line 24 are adjacent to each other. It can cause interference by piggybacking on other signals, which is a serious impediment to other parts of the circuit. For example, when the signal received from the antenna of the mobile communication terminal is 860MHz and the local signal flowing through the transmission line 24 is 900MHz, the 900MHz local signal with a high signal level is applied to the 860MHz received signal with a low signal level. If the piggybacking, the reception sensitivity of the terminal is significantly reduced, thereby reducing the call quality.

The waveguide shown in FIG. 2 shows a conventional stripline waveguide 60, which treats the upper and lower surfaces of the insulator substrate 64 as ground 62, and the high frequency signal transmission line 66 in the inner layer. ) Is composed of a structure consisting of.

Unlike the microstrip waveguide 20 described above, the stripline waveguide 60 is shielded in the vertical direction, but has the same problem as the microstrip waveguide 20 in the left and right transverse directions.

In addition, when the conventional microstrip waveguide 20 or the stripline waveguide 20 is applied to a printed circuit board of a mobile communication terminal, the waveguides 20 and 60 may be formed between two layers. Since the distance (H), the thickness (T) of the transmission line, and the dielectric constant (Er) of the interlayer insulator tend to be a constant constant in the manufacturing process, the impedance (W) of the transmission line is usually adjusted to achieve impedance matching. do. However, in the waveguide theory, the impedance is greatly changed according to the change in the width (W) of the transmission line, so it is easily affected by the error in the manufacturing process of the printed circuit board. Therefore, it is difficult to accurately match the impedance characteristics, and it must be subjected to a lot of trial and error. There was a disadvantage.

The present invention was developed to solve the above-mentioned conventional problems, and an object of the present invention is to provide a separate waveguide made of a microstrip or stripline as a transmission line on a printed circuit board (PCB). Unlike the use, since the waveguide is formed directly inside the printed circuit board, it can be usefully applied when it is difficult to use a waveguide separately configured in a mobile communication terminal having a small size and a high density of circuits, and at the same time, the high frequency transmission of the waveguide Completely shielding the top, bottom, left and right side of the line eliminates mutual interference with other surrounding signals and dramatically reduces transmission loss, thereby providing a three-dimensional waveguide inside the circuit to dramatically improve the characteristics of the circuit. To provide a printed circuit board.

In order to achieve the above object, it is laminated via a PCB inner layer, a PCB upper layer stacked on top of the PCB inner layer, a PCB lower layer stacked below the PCB inner layer, and another PCB layer above the PCB upper layer or Or a multilayer printed circuit board in which at least four or more layers including a PCB surface layer on which an electrical and electronic device is mounted are laminated without being interposed and stacked.
A high frequency transmission line is formed on the inner layer of the PCB, a ground layer is formed on the surface of the upper layer of the PCB, and a ground layer corresponding to the ground layer of the upper layer of the PCB is formed on the surface of the lower layer of the PCB. Maintaining a constant distance on both sides, the through grooves having a predetermined width penetrating the upper and lower parts of the PCB, upper and lower parts of the PCB in the vertical direction are continuously formed along the longitudinal direction of the transmission line, the upper part of the PCB By forming a plating layer having a predetermined thickness electrically connecting the ground layer of the lower portion of the PCB and at the same time, a space portion having a predetermined interval is formed between the plating layers on both sides, so that the upper and lower ground circumference of the cross section of the transmission line is inside the printed circuit board. Waveguides of a rectangular cross section, which are shielded by layers, both plating layers and spaces, are formed directly. The inside of the wave guide of the three-dimensional pattern of a printed circuit board provided in characterized in that there is provided.

In the present invention, while the waveguide is formed directly inside the printed circuit board, the circumference of the cross section of the transmission line of the waveguide is completely shielded by the upper and lower ground, both plating layers and the space portion, thereby mutually interacting with the surrounding signals. It is possible to provide a printed circuit board with an ideal lossless waveguide that does not cause interference and does not have an impedance shift.

The waveguide of the present invention as described above can be applied to the UHF local line, the power amplifier output line, the antenna-Rx line of the printed circuit board.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying exemplary drawings.

3 and 4 illustrate a structure of a printed circuit board having a three-dimensional waveguide formed therein according to the present invention. FIG. 3 is a cross-sectional view, and FIG. 4 is a perspective view of a main part of the waveguide in FIG. 3. It is.

The printed circuit boards shown in FIGS. 3 and 4 are enlarged cross-sectional views of a multi-layer PCB in which a complex circuit is distributed and printed and then stacked. The illustrated multilayer printed circuit board has a stacked structure from the first layer 110 to the sixth layer 160. Most of the main printed circuit boards (main boards) of the current mobile communication terminal or the printed circuit board for driving the LCD is used for such a multilayered printed circuit board.

The present invention implements a rectangular waveguide 100 in the printed circuit board of the multilayer structure as described above, and the upper, lower, left, and right sections of the transmission line 200 constituting the waveguide 100. It has an ideal structure that is completely shielded.

In the embodiment shown in the figure, the high frequency transmission line 200 is formed (printed) on the third PCB 130 (inner layer).

Meanwhile, the PCB first layer 110, the fifth layer 150, and the sixth layer 160 except for the PCB second layer 120 (upper layer), the third layer 130, and the fourth layer 140 (lower layer). ), Several other signal lines 112, 152, 162 are printed. The first PCB 110 is a surface layer of a printed circuit board, on which semiconductor devices, electrical / electronic devices, or components are mounted.

The ground layers 122 and 142 are formed on the upper and lower layers of the third PCB 130, that is, on the surfaces of the second layer 120 and the fourth layer 140. That is, the upper and lower layers of the transmission line 200 are used as the ground.

The second PCB 120 and the ground layers 122 and 142 on the surface of the fourth layer 140 are electrically connected to each other by the through groove 210.

The through groove 210 is continuously formed at a predetermined width along the longitudinal direction of the transmission line 200 while maintaining a predetermined distance with the transmission line 200 on both sides of the transmission line 200. That is, the through groove 210 penetrates the PCB second layer 120, the PCB third layer 130, and the PCB fourth layer 140 in the vertical direction along the length direction of the transmission line 200. Made of structure.

Plating layers 220 are formed on both inner wall surfaces of the both through grooves 210 by coating a conductive material with a predetermined thickness, and space portions having a predetermined interval are formed between the two plating layers 220. The plating layer 220 electrically connects the grounding layers 122 and 142 of the second PPCB layer 120 and the fourth PPCB layer 140, and a space portion formed between the plating layers 220. Further improve the shielding effect.

Therefore, the transmission line 200 has a structure in which the circumference of the cross section is shielded by the upper and lower ground layers 122 and 142, both plating layers 220, and the space part.

Meanwhile, in the embodiment shown in the drawing, the transmission line 200 is formed on the third PCB 130, the upper and lower layers in the form of the second layer 120 and the fourth layer 140. Consists of. However, the waveguide 100 of the present invention is not limited only to the example shown in the drawings.

For example, the inner layer where the transmission line 200 is formed may be set as the fourth layer 140, and upper and lower layers thereof may be set as the third layer 130 and the fifth layer 150. In addition, the inner layer where the transmission line 200 is formed may be set as the fifth layer 150, and upper and lower layers thereof may be set as the fourth layer 140 and the sixth layer 160.

The present invention made as described above has a form in which the top, bottom, left and right of the transmission line 200 is completely shielded inside the printed circuit board. According to the waveguide 100 of the present invention, an ideal square coaxial waveguide 300 as shown in FIG. 5 can be almost completely reproduced. Therefore, the characteristics of the transmission line of the waveguide according to the present invention can be accurately predicted by a generalized simulation program for the ideal rectangular coaxial waveguide 300 shown in FIG.

Thus, the waveguide according to the present invention, unlike the conventional waveguide made of a microstrip or stripline, can be completely shielded around. Therefore, there is little fear that the high frequency transmission line 200 causes frequency interference with other surrounding signals.

In addition, due to the perfect shielding as described above, since there is no impedance mismatch, it is possible to easily implement an ideal lossless waveguide (transmission line).

In particular, a separately configured waveguide cannot be used or very inefficient for the main board of a mobile communication terminal (cellular phone, PCS phone, PDA terminal, etc.) and a compact PCB driving circuit having a small size and high circuit density. However, according to the present invention, rather than using a separate waveguide, it is completely implemented in the printed circuit board itself, so that its use effect is very large.

For example, the waveguide structure of the present invention can be applied to a UHF local line, a power amplifier output line, an antenna-Rx line, or the like of a mobile communication terminal.

In the foregoing description, specific embodiments of the present invention shown in the accompanying drawings have been described in detail, but this is only an example and the protection scope of the present invention is not limited thereto. In addition, the embodiments of the present invention as described above can be variously modified and equivalent other embodiments by those of ordinary skill in the art within the technical spirit of the present invention, such modifications and equivalent other embodiments are It goes without saying that it belongs to the appended claims of the invention.

As described above, in the present invention, a rectangular waveguide is provided inside the printed circuit board itself and yet completely shields the top, bottom, left and right sides.

Conventionally, a waveguide provided separately, such as a microstrip waveguide or a stripline waveguide, has a disadvantage in that shielding of a transmission line is incomplete, causing interference with other surrounding signals, and increasing transmission loss. In addition, since it is influenced by the change of the width of the transmission line, it is easily affected by the error in the manufacturing process of the printed circuit board, which makes it difficult to accurately match the impedance characteristics.

However, according to the present invention, since the ideal rectangular coaxial waveguide with perfect shielding of the upper, lower, left and right of the transmission line can be reproduced almost completely inside the printed circuit board itself, it may cause interference with other surrounding signals. There is little concern and there is no impedance mismatch due to complete shielding, which provides an ideal lossless waveguide.

Claims (2)

The PCB inner layer, the PCB upper layer stacked on the upper part of the PCB inner layer, the PCB lower layer laminated on the lower part of the PCB inner layer, and the PCB upper layer laminated above or without another PCB layer laminated thereon In a printed circuit board having a multilayer structure in which at least four or more layers including a PCB surface layer on which electrical and electronic devices are mounted are stacked on an upper surface thereof, A high frequency transmission line is formed in the PCB inner layer, The ground layer is formed on the surface of the PCC upper layer, A ground layer corresponding to the ground layer of the upper portion of the PCB is formed on the surface of the lower portion of the PCB, While maintaining a constant distance to both sides of the transmission line of the PCB inner layer, a through hole having a predetermined width penetrating the upper and lower parts of the PCB upper layer, the PCB inner layer and the PCB lower layer is formed continuously along the longitudinal direction of the transmission line, On both sides of the through groove, a plating layer having a predetermined thickness electrically connecting the ground layer of the upper portion of the PCB and the ground layer of the lower portion of the PCB is formed and at the same time a space portion is formed between the plating layers on both sides. In the printed circuit board, a waveguide of a three-dimensional pattern is provided inside the cross-sectional rectangular waveguide directly shielded by the upper and lower ground layers, both plating layers, and the space portion of the transmission line. Printed circuit board. The method of claim 1, Wherein the waveguide is applied to at least one of a UHF local line, a power amplifier output line, or an antenna-Rx line.

Images