KR20110076517A - A siw filter structure embeded in circuit board and a method thereof - Google Patents

Abstract

PURPOSE: An SIW(Surface Integrated Waveguide) filter embedded in a substrate and a manufacturing method thereof are provided to implement the integration of a system and reduce the weight and size of the device by embedding the SIW filter in the substrate. CONSTITUTION: An SIW filter(100) is formed in an inner layer(60) of a substrate(200). A via(70) is formed between the inner layers of the substrate and a surface layer(50) of the substrate. A correction circuit(80) corrects the distortion of inductance elements due to via. The correction circuit is composed of one series line and two shunt stub lines. The series line is formed on both sides of the correction circuit.

Description

Subsidiary filter for board | substrate interior and its manufacturing method {A SIW FILTER STRUCTURE EMBEDED IN CIRCUIT BOARD AND A METHOD THEREOF}

The present invention relates to a SIW filter structure, and more particularly, to a SIW filter structure that can be embedded and used in a substrate.

Background Art A waveguide is known as a structure for transmitting electrical energy or signals of high frequency or higher than conventional microwaves. 1 is a view illustrating the shape of a conventional waveguide fabricated using metal, and since the loss of the signal is very small compared to other transmission lines such as microstrip lines and strip lines, it is necessary for defense or aviation requiring high frequency and low loss. Widely used for space.

However, since these metal waveguides are very large and heavy, they are difficult to use in integrated systems. Therefore, they are difficult to use in areas requiring light weight or small size.

Meanwhile, surface integrated waveguides (SIWs) are designed to be easily integrated into a system while using the low loss characteristic of the metal waveguide.

FIG. 2 illustrates the structure of the SIW. As illustrated in FIG. 2, the SIW filter 100 includes two metal patterns 10 and 20 formed on a substrate and metal vias 20 formed around the metal pattern. ) And is filled with a dielectric 40 having a constant dielectric constant between the metal patterns 10 and 20.

In this structure, the plurality of vias 30 formed between the metal patterns serve as metal walls, and thus operate similarly to the metal waveguide shown in FIG. There is an advantage that the size can also be miniaturized.

Bandpass filters using such a SIW structure have been developed. To construct the bandpass filter, a magnetic resonance period and an electromagnetic coupling are required.

Figure 3 (a) is a diagram illustrating the resonance period magnetic field coupling, Figure 3 (b) is a diagram illustrating the resonance period field coupling. By appropriately combining the structures of the magnetic field coupling and the electric field coupling, a bandpass filter as shown in Figs. 4A and 4B can be constituted.

FIG. 5 shows the characteristics of the 60 ㎓ filter implemented as described above. As the quality factor value of the resonator is larger than that of other transmission lines, it can be seen that the selectivity characteristic of the filter is very excellent. However, the aforementioned Surface Integrated Waveguide (SIW) filter is always present on the substrate surface, i.e., the top layer of the substrate, and thus is not suitable for module integration and miniaturization.

FIG. 6 is a view illustrating a SIW filter formed on the substrate surface 50. As the SIW filter is formed on the surface 50 of the substrate, semiconductor chips such as MMIC may be used to implement the SIW filter 100 in actual system module implementation. ) Becomes a region that is not practically utilized, and thus does not contribute to module integration and miniaturization.

Accordingly, an object of the present invention is to propose a structure of a SIW band pass filter capable of preserving characteristics of a SIW filter while embedding an existing SIW filter into a substrate.

The present invention provides an electrical device including a surface integated waveguide (SIW) filter, which is an invention for achieving the above object, comprising: a substrate; An SIW filter inserted into the substrate inner layer; A via formed at an inner side of the substrate having one side end formed at a surface layer of the substrate and the other end formed at the SIW filter; And a correction circuit connected to the SIW filter from the other end of the via formed in the inner layer of the substrate to correct the distortion of the inductance component caused by the via.

Here, the correction circuit is composed of one series line formed at both ends of the correction circuit and two shunt stub lines protruding laterally from the series line, so as to eliminate distortion of inductance components caused by the vias. You can correct it. In addition, the correction circuit is coupled to the SIW filter and the via in the substrate to allow the semiconductor chip to be mounted on the SIW filter.

In addition, the manufacturing method of the electric device comprising a surface-integrated waveguide filter according to the present invention, forming a surface-integrated waveguide filter (SIW filter) in the substrate inner layer; Forming a via from the surface layer of the substrate to an inner layer of the substrate on which the SIW filter is formed; Forming a correction circuit at one end of the SIW filter from one end of the via formed in the inner layer of the substrate; And mounting a semiconductor chip on top of the SIW filter, wherein the correction circuit is configurable to correct distortion of inductance components caused by the via.

The distortion correction of the inductance component caused by the via is made by forming one series line formed at both ends of the correction circuit and two shunt stub lines protruding laterally from the series line, so that the SIW filter Even if the inside of the substrate is formed, the characteristics of the filter can be derived.

According to the present invention, since the SIW filter can be mounted inside the substrate while preserving the characteristics of the SIW filter by providing a correction circuit capable of preserving the characteristics of the SIW filter while embedding the existing SIW filter into the substrate. A very advantageous effect can be obtained in miniaturization and weight reduction of the system and integration of the system.

EMBODIMENT OF THE INVENTION Hereinafter, the board | substrate built-in SIW filter structure which concerns on this invention is demonstrated below with reference to attached drawing.

7 is a view schematically showing a SIW filter embedded in a substrate according to the present invention. As shown in FIG. 7, the SIW filter 100 is formed from the inner layer 60 under the surface layer 50 of the substrate 200 in the lower direction of the substrate.

As described with reference to FIG. 2, the SIW filter 100 is composed of two metal patterns 10 and 20 formed on a substrate and metal vias 20 formed around the metal pattern. 20) are filled with a dielectric 40 having a constant dielectric constant. As the SIW filter 100 is formed inside the substrate, vias 70 are formed from the surface layer 50 of the substrate 200 to the inner layer 60 to extract the characteristics of the filter.

However, when the characteristics of the filter 100 are extracted from the substrate surface layer 50 through the via 70 from the substrate surface layer 50, the vias connecting the inner layer 60 and the surface layer 50 may be extracted. 70 is caused by the inductance component, and the inductance component of the via 70 caused causes the characteristics of the filter 100 to be distorted and thus cannot be applied to the actual system.

In the present invention, to correct the characteristic distortion to restore the filter 100 characteristics, a correction circuit capable of correcting the inductance component of the via 70 is formed in the periphery of the filter 100.

8 shows the SIW filter 100 formed on the inner layer 60 of the substrate 200, and forms a via 70 between the surface layer 50 of the substrate and the inner layer 60 of the substrate. A correction circuit 80 capable of correcting the inductance component of 70 is inserted into the inner layer 60. If the inductance component caused by the via 70 can be corrected by the correction circuit 80, as shown in FIG. 8, the SIW filter is formed inside the substrate, so that a semiconductor chip such as the MMIC 300 is formed into the SIW filter. As it can be mounted on the forming surface of (100), it has a more advantageous advantage in miniaturization and light weight.

In order to correct the inductance component of the via, these characteristics need to be extracted first. FIG. 9 is a view illustrating a structure in which only vias and microstripline lines are connected without a special compensation circuit. Referring to the filter characteristics in this structure, as shown in line 14 of FIG. The matching characteristic can also be seen to be very bad, as shown by line 15. Therefore, it can be seen that the built-in filter 100 loses its characteristics.

11A shows a filter structure having a correction circuit 80 according to the present invention. As shown in FIG. 11A, the correction circuit 80 is composed of a series line 81 and two shunt stubs 82. The structure of the SIW filter including the correction circuit 80 is as shown in Fig. 11B.

As shown in FIG. 11B, a space in which a semiconductor chip such as an MMIC is mounted and a transition portion 90 are formed in the uppermost layer of the substrate. Via 70 is formed from an extension of transition portion 90 and is connected to one end of correction circuit 80 formed in inner layer 60. The correction circuit 80 is formed of a microstrip line and connected to the end of the SIW.

12 is a view schematically showing a process of impedance matching by the correction circuit 70 according to the present invention. The input impedance by the via 70 is distorted and distorted from the center as indicated by the point a1 of FIG. 12. In this case, the series line 81 first moves to the point a2, and the shunt stub 82 moves to the point a3, so that impedance matching is realized.

Referring to FIG. 10 again, the characteristic of the structure in which the correction circuit 80 is inserted is shown in FIG. It can be seen that greatly improved as shown.

In the method of manufacturing an electric device including a surface integrated waveguide filter, first, a surface integrated waveguide filter (SIW filter) is formed in a sublayer in a substrate, and a via is formed from the surface layer of the substrate to an inner layer of the substrate on which the SIW filter is formed. . Subsequently, a correction circuit is formed at one end of the SIW filter from one end of the via formed in the inner layer of the substrate and connected thereto.

In this case, the distortion correction of the inductance component caused by the via may be achieved by forming one series line formed at both ends of the correction circuit and two shunt stub lines protruding laterally from the series line. The correction circuit in the present invention is adapted to correct distortion of inductance components caused by vias.

FIG. 13 shows actual dimensions of the correction circuit 80 shown in FIG. 11, which is a circuit capable of correcting distortion caused by vias in the vertical connection through vias with other components other than a filter. . As shown in Fig. 13, the value of L1 is 300 µm, L2 is 500 µm, L3 is 1500 µm, SL1 is 250 µm, SW is 150 µm, W1 is 100 µm, W2 is 470 µm, W3 is 200 µm, SL2 was designed to be 250µm and G1 = G2 = 80µm.

FIG. 14 is a diagram illustrating a characteristic of a built-in filter including a correction circuit optimized to the aforementioned design value. As shown in FIG. 14, when the optimized correction circuit 80 is connected to the built-in SIW filter 100 to extract the characteristic, the correction circuit is compared with the line 23 indicating the insertion loss when the correction circuit is not applied. It can be seen that the insertion loss in the case where (80) is applied is significantly reduced in line 24.

15 is a diagram showing the impedance matching characteristic, and it can be seen that the impedance matching characteristic is improved when the correction circuit is inserted (line 26) compared with the case where the correction circuit is not included (line 26).

FIG. 16 is a view showing the structure and dimensions of the SIW filter illustrated in the present invention. Like the correction circuit, the structure and the dimensions thereof should be optimized when the filter is embedded in the substrate. have.

In addition, Figure 17 is a view showing the shape of the actual built-in filter produced in accordance with an embodiment of the present invention.

According to the present invention as described above, it is possible to mount the SIW filter inside the substrate while preserving the characteristics of the SIW filter by providing a correction circuit capable of preserving the characteristics of the SIW filter while embedding the existing SIW filter into the substrate. Therefore, it is very advantageous for miniaturization and weight reduction of the device.

The above description is merely illustrative of the technical idea of the present invention, and those skilled in the art to which the present invention pertains may make various modifications and changes without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are not intended to limit the technical idea of the present invention but to describe the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The protection scope of the present invention should be interpreted by the claims, and all technical ideas within the equivalent scope should be interpreted as being included in the scope of the present invention.

1 shows a conventional metal waveguide;

2 schematically shows the structure of a SIW filter;

Figure 3 (a) is a configuration schematically showing the magnetic field coupling of the SIW filter, Figure 3 (b) is a configuration schematically showing the field coupling.

4 (a) and 4 (b) schematically show an SIW filter designed as a bandpass filter, and (a) shows a schematic drawing of the SIW filter and (b) a fabricated SIW filter.

5 is a graph showing characteristic values of the SIW bandpass filter.

6 shows an example in which a SIW filter is mounted on a substrate surface.

7 shows an example in which a SIW filter is mounted inside a substrate.

8 is a view showing an example in which the MMIC chip is mounted on the surface of the substrate on which the SIW filter is mounted after the SIW filter is mounted inside the substrate.

9 illustrates an example of coupling to a microstrip line without a correction circuit.

10 is a diagram illustrating a frequency characteristic with or without a correction circuit.

11A illustrates an example of coupling to a microstrip line with a correction circuit.

FIG. 11B schematically illustrates the layer structure of an SIW filter with a correction circuit; FIG.

12 is a diagram schematically showing impedance correction by a series line and a shunt line of a correction circuit.

FIG. 13 is a diagram showing dimension values in the circuit shown in FIG. 11; FIG.

FIG. 14 is a view showing characteristics of a built-in filter including a correction circuit optimized to the design value of FIG. 13. FIG.

Fig. 15 is a graph showing the impedance matching characteristics when the correction circuit is not included and when the correction circuit is entered.

FIG. 16 is a diagram showing a SIW bandpass filter and dimension values thereof; FIG.

Fig. 17 is a diagram showing a practical built-in SIW filter.

Claims (5)

In an electrical device comprising a surface integated waveguide (SIW) filter, Board; An SIW filter inserted into the substrate inner layer; A via formed at an inner side of the substrate having one side end formed at a surface layer of the substrate and the other end formed at the SIW filter; A surface integrated waveguide filter including a correction circuit connected to the SIW filter from the other end of the via formed in the inner layer of the substrate to correct distortion of an inductance component caused by the via. Electrical element included in the layer. The method of claim 1, The correction circuit includes a surface integrated waveguide filter including a series line formed at both ends of the correction circuit and two shunt stub lines protruding laterally from the series line. Electrical element included in the layer. The method of claim 2, And the correction circuit includes a surface integrated waveguide filter in the inner layer of the substrate, wherein the surface integrated waveguide filter is coupled to the SIW filter and the via in the substrate. In the manufacturing method of the electric element comprising a surface-integrated waveguide filter, Forming a surface integrated waveguide filter (SIW filter) in the substrate inner layer; Forming a via from the surface layer of the substrate to an inner layer of the substrate on which the SIW filter is formed; Forming a correction circuit at one end of the SIW filter from one end of the via formed in the inner layer of the substrate; Mounting a semiconductor chip as an upper layer of said SIW filter, And the correction circuit is adapted to correct distortion of inductance components caused by the vias in the inner layer of the substrate. 5. The method of claim 4, The distortion correction of the inductance component caused by the via is formed by forming one series line formed at both ends of the correction circuit and two shunt stub lines protruding laterally from the series line. A method of manufacturing an electrical device comprising a surface integrated waveguide filter to the inner layer of the substrate.

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