JP5241591B2 - Connection structure between high-frequency circuit and high-frequency line - Google Patents

Description

  The present invention relates to a connection structure between a high-frequency circuit and a high-frequency line, and more particularly to a connection structure using conductive wires and slots.

  When a semiconductor element such as an MMIC is mounted on a circuit board and electrically connected, a method of connecting a line conductor constituting a microstrip line of the circuit board and the semiconductor element using a conductive wire such as a bonding wire is used. However, there was a problem with this method.

  That is, when a semiconductor element and a line conductor on a circuit board are connected using a conductive wire, the inductance component of the conductive wire increases as the conductive wire moves away from the ground electrode, and a signal due to impedance mismatch between the conductive wire and the line conductor is generated. There was a problem that reflection would occur. This problem can be ignored to some extent in the low frequency region, but causes a large characteristic deterioration that cannot be ignored in the high frequency region.

  In order to reduce the deterioration of characteristics due to this problem, it is necessary to bring the conducting wire closer to the ground electrode and shorten the length of the conducting wire. For this reason, a semiconductor element is mounted in a recess formed in the circuit board so that the connection terminal surface of the semiconductor element and the surface of the circuit board are brought closer, thereby bringing the lead wire closer to the ground electrode and shortening the length of the lead wire. There is a technique (see, for example, Patent Document 1).

  In addition, there is a method of increasing impedance by matching capacitance by a method of connecting a conductive wire to a single plate capacitor arranged on a line conductor or a method of forming a stub or the like on a line conductor connecting the conductive wire.

JP 2000-22043 A

  However, the above-described prior art has the following problems.

  That is, the method of forming the recesses on the circuit board is often used for ceramic multilayer wiring boards, but there is a problem that the bottom surface of the recesses tends to be convex and the mounted semiconductor element may be inclined. In addition, there is a problem that the thickness of the bottom portion of the concave portion of the substrate becomes thin and the strength may be insufficient. Furthermore, there is a problem that the structure and the manufacturing process are complicated.

  In addition, in the method of connecting a lead wire to a single plate capacitor arranged on a line conductor, the structure and the manufacturing process are complicated, and the capacitance of the single plate capacitor is determined, so that the lead wire length due to mounting deviation of the semiconductor element is determined. There has been a problem that the variation in inductance due to variations cannot be corrected.

  Further, in the method of forming a stub or the like on the line conductor connecting the conductive wires, the greater the inductance component of the conductive wire, the narrower the frequency band in which impedance matching can be performed, and the more sensitive to the size and position of the stub. For this reason, since a high dimensional accuracy is required for the circuit board, in many cases, a thin film substrate is used. Thereby, there existed a problem that a manufacturing process and manufacturing cost increased compared with a thick film printed circuit board.

  The present invention has been devised in view of such problems in the prior art, and its purpose is simple and easy to manufacture between a high-frequency circuit such as a semiconductor element and a high-frequency line formed on a circuit board or the like. Is to provide a simple connection structure.

The connection structure between the high-frequency circuit of the present invention and the high-frequency line includes a dielectric substrate, a line conductor disposed on one main surface or inside the dielectric substrate, and one main surface on the other main surface of the dielectric substrate. A grounding conductor disposed so as to be in contact with a slot functioning as an antenna capable of transmitting and receiving a high-frequency signal; and the high-frequency signal disposed adjacent to the slot on the other main surface side of the grounding conductor A high-frequency component including a high- frequency circuit having a high-frequency signal terminal for at least one of the input and output of the input, and a conductive wire that has one end connected to the high-frequency signal terminal and functions as an antenna capable of transmitting and receiving the high-frequency signal The line conductor is disposed so as to traverse the slot, and is electromagnetically coupled to the slot, and the dielectric substrate and With serial ground conductor constitutes a high-frequency line for transmitting the high-frequency signal, the high-frequency signal terminal is disposed on the principal surface opposite to the side facing to the ground conductor in the high frequency component, the conductor A bonding wire, wherein the conductive wire is disposed on the other main surface side of the ground conductor so as to cross the slot, and the high-frequency circuit and the high-frequency line are electromagnetically connected to each other. It is.

Further, the connection structure between the high-frequency circuit and the high-frequency line of the present invention is the above-described configuration, wherein the conducting wire has a non-grounded end with the other end separated from the ground conductor and floating in the air. The length is (2n-1) / 4 times the wavelength of the high-frequency signal (n is a natural number).

Further, the connection structure of a high-frequency circuit and the transmission line of the present invention, in the above Ki構 formed, on the opposite side of the high-frequency signal terminal in between the slots in the other main surface of said dielectric substrate, said ground An island-shaped conductor insulated from the conductor is disposed, and the other end of the conducting wire is connected to the island-shaped conductor .

  In addition, in this specification, a conducting wire is a linear or strip | belt-shaped conductor, for example, includes a thing like a ribbon wire. In addition, electromagnetic connection means that a high-frequency signal is conducted through electromagnetic waves. Furthermore, when the line conductor crosses over the slot, the line conductor is arranged so as to be spaced from the slot, and when viewed in plan (when viewed from the normal direction at the center of gravity of the slot), the line conductor is Means that it intersects with both of the two long sides facing each other. Similarly, when the conductor crosses over the slot, it means that the conductor is arranged at a distance from the slot, and that the conductor intersects with both of the two opposite long sides of the slot in plan view. .

The wavelength of the high-frequency signal in the slot is, for example, the wavelength λ in the slot when the relative permittivity of the dielectric substrate is εr and the periphery of the slot on the other main surface side of the ground conductor is filled with air. If the wavelength in vacuum is λ ₀ , then λ = λ ₀ / {(εr + 1) / 2} ^1/2 .

  According to the connection structure between the high-frequency circuit and the high-frequency line of the present invention, the line conductor that transmits a high-frequency signal together with the dielectric substrate and the ground conductor is disposed on one main surface side of the ground conductor so as to cross the slot. The conductor that is electromagnetically coupled to the slot that functions as an antenna capable of transmitting and receiving high-frequency signals and that is connected to the high-frequency signal terminal of the high-frequency circuit and functions as an antenna capable of transmitting and receiving high-frequency signals is a ground conductor. The other main surface is arranged so as to cross the slot. As a result, the high frequency signal transmitted from the conductor can be received by the slot, and the high frequency signal transmitted from the slot can be received by the conductor, so that the high frequency circuit and the high frequency line are electromagnetically favorable. Connected. Therefore, the circuit board recesses and the matching elements such as single-plate capacitors and stubs required in the conventional structure are all unnecessary, and there is no need to use a thin film substrate. A connection structure with a track can be obtained.

  Further, according to the connection structure between the high-frequency circuit and the high-frequency line of the present invention, since both the conductor and the slot function as an antenna, the positional relationship between the conductor and the slot is high-frequency signal transmission between the conductor and the slot. The effect on characteristics is small. For this reason, the positional relationship between the conducting wire and the slot can be set freely to some extent, and the influence of manufacturing variations is reduced. Therefore, it is possible to obtain a connection structure between a high-frequency circuit and a high-frequency line that is highly designed and easy to manufacture.

  Furthermore, according to the connection structure between the high-frequency circuit and the high-frequency line of the present invention, the conductive wire has the other end insulated from the ground conductor to be a non-grounded end, and has an electrical length of (2n− 1) When 1/4 (n is a natural number), the conducting wire functions well as a monopole antenna, so that the high-frequency circuit and the high-frequency line can be more electromagnetically connected.

  Furthermore, according to the connection structure between the high-frequency circuit and the high-frequency line of the present invention, when the length of the slot is n / 2 times the wavelength of the high-frequency signal in the slot (n is a natural number), the slot is excellent as an antenna. Since it functions, the high-frequency circuit and the high-frequency line can be more electromagnetically connected.

It is an external appearance perspective view which shows typically the connection structure of the high frequency circuit of the 1st example of embodiment of this invention, and a high frequency track | line. It is a longitudinal cross-sectional view which shows typically the connection structure of the high frequency circuit and high frequency track | line shown in FIG. It is an external appearance perspective view which shows typically the connection structure of the high frequency circuit of the 2nd example of embodiment of this invention, and a high frequency track | line. It is a graph which shows the simulation result of the electrical property of the connection structure of the high frequency circuit of the 1st example of embodiment of this invention, and a high frequency track | line.

Hereinafter, a connection structure between a high-frequency circuit and a high-frequency line according to the present invention will be described in detail with reference to the accompanying drawings.
(First example of embodiment)
FIG. 1 is an external perspective view schematically showing a connection structure between a high-frequency circuit and a high-frequency line in a first example of an embodiment of the present invention. FIG. 2 is a longitudinal sectional view schematically showing a connection structure between the high-frequency circuit and the high-frequency line shown in FIG.

  As shown in FIGS. 1 and 2, the connection structure between the high-frequency circuit and the high-frequency line in this example is a dielectric substrate 21, a line conductor 22, a ground conductor 23, a slot 30, a high-frequency component 40, a high-frequency component, and the like. A signal terminal 41 and a conducting wire 50 are provided.

  The dielectric substrate 21 is configured by laminating a plurality of dielectric layers. The line conductor 22 is disposed on one main surface of the dielectric substrate 21. The ground conductor 23 is disposed so that one main surface of the ground conductor 23 is in contact with the other main surface of the dielectric substrate 21. The ground conductor 23 is formed with a slot 30 that functions as an antenna capable of transmitting and receiving high-frequency signals. The line conductor 22 is disposed so as to cross the slot 30 and is electromagnetically coupled to the slot 30, and transmits a high-frequency signal together with the dielectric substrate 21 and the ground conductor 23. Is configured. In addition, one end of the line conductor 22 is an open end near the slot 30, and the other end of the line conductor 22 reaches the end of the dielectric substrate 21 (in fact, the other end of the line conductor 22 is a high frequency Connected to other circuits to transmit signals).

  The high-frequency component 40 is disposed adjacent to the slot 30 on the other main surface side of the ground conductor 23. The high-frequency component 40 has a built-in high-frequency circuit (not shown), and the high-frequency signal terminal 41 of the high-frequency circuit is disposed on the upper surface of the high-frequency component 40. The high frequency signal terminal 41 is used for inputting and outputting a high frequency signal. The conducting wire 50 has one end connected to the high frequency signal terminal 41 and the other end separated from the ground conductor 23 and floated in the air, and functions as an antenna capable of transmitting and receiving high frequency signals. Conductive wire 50 is arranged on the other main surface side of ground conductor 23 so as to cross over slot 30.

  Note that each of the line conductor 22 and the conductor 50 is spaced apart from the ground conductor 23 and the slot 30 and is opposed to the slot 30 at the center in the length direction of the slot 30 when viewed in plan. It is arranged so as to be orthogonal to both of the two long sides.

  According to the connection structure of the high-frequency circuit and the high-frequency line of this example having such a configuration, the line conductor 22 is arranged on one main surface side of the ground conductor 23 so as to cross over the slot 30, and the high-frequency signal is transmitted. The conductor 50 that functions as an antenna capable of transmitting and receiving high-frequency signals and crosses the slot 30 on the other main surface side of the ground conductor 23 while electromagnetically coupling with the slot 30 that functions as an antenna capable of transmitting and receiving. Is arranged. Therefore, the slot 30 can receive a high-frequency signal transmitted from the lead wire 50 connected to the high-frequency signal terminal 41 of the high-frequency circuit built in the high-frequency component 40, and the line conductor 22 constituting the high-frequency line A high frequency signal transmitted from the electromagnetically coupled slot 30 can be received by the conductor 50. As a result, the high-frequency circuit built in the high-frequency component 40 and the high-frequency line composed of the dielectric substrate 21, the line conductor 22, and the ground conductor 23 are connected electromagnetically satisfactorily, which is necessary in the conventional structure. Since all the concave portions of the circuit board and matching elements such as single-plate capacitors and stubs are not required, and it is not necessary to use a thin film substrate, a connection structure between a high-frequency circuit and a high-frequency line that is simple and easy to manufacture can be obtained. it can.

  In addition, according to the connection structure between the high-frequency circuit and the high-frequency line in this example, both the conductive wire 50 and the slot 30 function as an antenna. Therefore, the positional relationship between the conductive wire 50 and the slot 30 is the same as that between the conductive wire 50 and the slot 30. The effect on the transmission characteristics of high-frequency signals is small. For this reason, the positional relationship between the conducting wire 50 and the slot 30 can be freely set to some extent, and the influence of manufacturing variations is reduced. Therefore, it is possible to obtain a connection structure between a high-frequency circuit and a high-frequency line that is highly designed and easy to manufacture.

  Furthermore, according to the connection structure between the high-frequency circuit and the high-frequency line of this example, the conducting wire 50 is in a state where the other end is separated from the ground conductor 23 and floats in the air to become a non-grounded end, and the electrical length Is set to 1/4 times the wavelength of the high-frequency signal. Therefore, since the conducting wire 50 functions well as a monopole antenna, the high-frequency circuit built in the high-frequency component 40 and the high-frequency line composed of the dielectric substrate 21, the line conductor 22, and the ground conductor 23 can be more electromagnetically improved. Can be connected.

  Furthermore, according to the connection structure between the high-frequency circuit and the high-frequency line of this example, the length of the slot 30 is set to ½ times the wavelength of the high-frequency signal in the slot 30, so that the slot 30 serves as an antenna. Since it functions satisfactorily, the high-frequency circuit built in the high-frequency component 40 and the high-frequency line composed of the dielectric substrate 21, the line conductor 22, and the ground conductor 23 can be more electromagnetically connected.

  Furthermore, according to the connection structure between the high-frequency circuit and the high-frequency line of the present example, the conductive wire 50 is arranged so as to be orthogonal to the length direction of the slot 30 when viewed in plan, and thus is generated from the conductive wire 50. Since the direction of the electric field and magnetic field in the electromagnetic wave coincides with the direction of the electric field and magnetic field in the electromagnetic wave generated from the slot 30 in the horizontal direction, the high-frequency circuit built in the high-frequency component 40, the dielectric substrate 21, the line conductor 22, and the ground The high-frequency line made of the conductor 23 can be more electromagnetically connected.

  Still further, according to the connection structure between the high-frequency circuit and the high-frequency line in this example, the line conductor 22 is arranged so as to be orthogonal to the length direction of the slot 30 when viewed in plan, Since the direction of the magnetic field generated around and the direction of the magnetic field in the electromagnetic wave generated from the slot 30 coincide in the horizontal direction, the line conductor 22 and the slot 30 can be satisfactorily electromagnetically coupled.

  In the connection structure of the high-frequency circuit and the high-frequency line in this example, the material of the dielectric substrate 21 is not particularly limited as long as it has a characteristic that does not hinder the transmission of high-frequency signals, and a resin such as glass epoxy is used. Although it is possible to use it, it is desirable to use dielectric ceramics from the viewpoint of processing accuracy and ease of manufacture. The relative dielectric constant of the dielectric substrate 21 is set to about 2 to 20, for example.

  For the line conductor 22 and the ground conductor 23, for example, a highly conductive metal such as aluminum or copper can be used, and the thickness thereof is, for example, about 3 μm to 50 μm. The slot 30 is formed so as to penetrate the ground conductor 23, and is formed in a rectangular shape having a width of about 0.05 mm to 0.5 mm and a length of about 0.3 mm to 4 mm, for example, according to the frequency of the high frequency signal. The

  The dielectric substrate 21 on which the line conductor 22 and the ground conductor 23 are arranged can be manufactured, for example, as follows. First, using a slurry obtained by adding and mixing a suitable organic solvent and solvent to a ceramic raw material powder mainly composed of glass, alumina, aluminum nitride, etc., a ceramic green sheet is formed by a doctor blade method or a calender roll method. Make it. Next, a paste prepared by adding an appropriate oxide, organic solvent, etc. such as alumina, silica, magnesia, etc. to the metal powder is applied to the surface of the ceramic green sheet by a thick film printing method, and with a conductor paste A ceramic green sheet is produced. Next, the obtained ceramic green sheets with a conductive paste are laminated and pressed using a hot press apparatus to form a laminate. The obtained laminate is about 850 ° C. to 1000 ° C. when the dielectric substrate 21 is made of glass ceramics, about 1500 ° C. to 1700 ° C. when it is alumina ceramics, and 1600 ° C. to 1900 ° C. when aluminum nitride ceramics are used. It is produced by firing at a peak temperature of about ° C. The metal powder is preferably copper, gold or silver when the dielectric substrate 21 is made of glass ceramics, and tungsten or molybdenum when the dielectric substrate 21 is made of alumina ceramics or aluminum nitride ceramics.

  As the high-frequency component 40 in which the high-frequency circuit is incorporated and the high-frequency signal terminal 41 is disposed, for example, an electronic component such as a semiconductor element can be exemplified. The conducting wire 50 is made of a metal wire such as gold or aluminum, and has a thickness of, for example, about 0.01 mm to 0.05 mm, and can be easily formed using, for example, a wire bonder. To float the other end of the conducting wire 50 in the air, for example, after connecting one end of the conducting wire 50 to the high frequency signal terminal 41, by adjusting the state of the place where the other end of the conducting wire 50 is connected and the setting of the wire bonder, The other end of the conducting wire 50 may be prevented from being connected, and the other end of the conducting wire 50 can be suspended in the air by the elasticity of the conducting wire 50. Furthermore, the shape of the conducting wire 50 can be stabilized by covering and fixing the conducting wire 50 and its periphery with a resin.

(Second example of embodiment)
FIG. 3 is an external perspective view schematically showing a connection structure between the high-frequency circuit and the high-frequency line in the second example of the embodiment of the present invention. Note that in this example, only differences from the first example described above will be described, and the same components will be denoted by the same reference numerals, and redundant description will be omitted.

  In the connection structure between the high-frequency circuit and the high-frequency line in this example, as shown in FIG. 3, an island insulated from the ground conductor 23 is provided on the opposite side to the high-frequency signal terminal 41 with the slot 30 of the ground conductor 23 in between. A conductor 60 is disposed, and the other end of the conductor 50 is connected to the island conductor 60. Note that the island-shaped conductor 60 is disposed away from the ground conductor 23 at the center of the through hole formed in the ground conductor 23 on the other main surface of the dielectric substrate 21.

  According to the connection structure between the high-frequency circuit and the high-frequency line of this example having such a configuration, the ground conductor 23 is insulated from the ground conductor 23 on the side opposite to the high-frequency signal terminal 41 with the slot 30 of the ground conductor 23 interposed therebetween. Since the other end of the conducting wire 50 is connected to the island-shaped conductor 60, both ends of the conducting wire 50 can be fixed, so that the shape of the conducting wire 50 is stable and highly reliable, The connection structure can be obtained.

(Modification)
The present invention is not limited to the first and second examples of the embodiment described above, and various modifications and improvements can be made without departing from the gist of the present invention.

  For example, in the example of the embodiment described above, an example in which the high-frequency component 40 incorporating the high-frequency circuit is disposed on the ground conductor 23 is shown, but the high-frequency component 40 incorporating the high-frequency circuit is the other of the ground conductor 23. It may be arranged on another dielectric substrate arranged on the main surface. Further, the high frequency circuit may be configured by a strip line or the like formed on another dielectric substrate disposed on the other main surface of the ground conductor 23.

  In the example of the embodiment described above, an example in which the length of the slot 30 is ½ times the wavelength of the high-frequency signal in the slot 30 is shown. However, if the length is n / 2 times (n is a natural number) Therefore, for example, the length may be the same as the wavelength of the high-frequency signal, or 3/2 times the wavelength of the high-frequency signal.

  Furthermore, in the example of the above-described embodiment, each of the line conductor 22 and the conductive wire 50 has been illustrated as being orthogonal to the slot 30 at the center in the length direction of the slot 30 when viewed in plan. They may be crossed at an angle, or may be crossed at a location deviated from the center of the slot 30 in the length direction.

  Furthermore, in the second example of the above-described embodiment, the example in which the island-shaped conductor 60 is arranged at the center of the through hole formed in the ground conductor 23 and separated from the ground conductor 23 is shown. The island-shaped conductor 60 may be disposed on the ground conductor 23 via an insulator.

  Furthermore, in the example of the embodiment described above, the case where the slot 30 is rectangular is shown, but other shapes may be used as long as it functions as a slot. For example, an oval or dumbbell-shaped slot 30 may be used. Absent.

  Furthermore, in the example of the embodiment described above, the line conductor 22 is disposed on one main surface of the dielectric substrate 21, and the microstrip line type high-frequency line is formed by the line conductor 22, the dielectric substrate 21, and the ground conductor 23. However, the present invention is not limited to this. For example, two grounding conductors are further arranged on both sides in the width direction of the line conductor 22 on the one main surface of the dielectric substrate 21 so that the line conductor 22, the dielectric substrate 21, the grounding conductor 23, and the line conductor 22 are arranged. An undergrounded coplanar line type high-frequency line may be configured by two ground conductors arranged on both sides in the width direction. Further, the line conductor 22 may be disposed inside the dielectric substrate 21. Further, the line conductor 22 is disposed inside the dielectric substrate 21, and the second ground conductor is disposed on one main surface of the dielectric substrate 21, so that the line conductor 22, the dielectric substrate 21, the ground conductor 23, and the second conductor A stripline type high frequency line may be constituted by two ground conductors.

  Next, a specific example of the connection structure between the high-frequency circuit and the high-frequency line of the present invention will be described.

  The electrical characteristics in the connection structure between the high-frequency circuit and the high-frequency line in the first example of the embodiment shown in FIGS. 1 and 2 were calculated by simulation based on electromagnetic field analysis. As calculation conditions, the relative permittivity and thickness of the dielectric substrate 21 were set to 9.4 and 0.15 mm, respectively. The thickness of the ground conductor 23 was 0.01 mm. The slot 30 has a rectangular shape with a width of 0.09 mm and a length of 0.85 mm. The line conductor 22 had a thickness of 0.01 mm and a width of 0.14 mm, and one end, which was an open end, was positioned at a distance of 0.275 mm from the center of the slot 30 in the width direction. The high-frequency component 40 was modeled as a dielectric having a relative dielectric constant of 9.5 and a thickness of 0.1 mm, and the high-frequency signal terminal 41 was formed in a square shape with a side of 0.1 mm arranged on the upper surface of the high-frequency component 40. The length of the conducting wire 50 was 0.913 mm, and the other end of the conducting wire 50 was 0.05 mm away from the ground conductor 23 and floated in the air.

  Then, with the high frequency signal terminal 41 as port 1 and the other end of the line conductor 22 as port 2, the transmission characteristics (S12) and reflection characteristics (S11, S22) were calculated. FIG. 4 is a graph showing the results, in which the horizontal axis represents frequency and the vertical axis represents attenuation. According to the graph shown in FIG. 4, in the vicinity of 76 GHz, S11 exceeds -20 dB, S22 also exceeds -15 dB, impedance is well matched, and good connection characteristics with little transmission loss are obtained. I understand that. This confirmed the effectiveness of the present invention.

21: Dielectric substrate
22: Line conductor
23: Ground conductor
30: Slot
41: High frequency signal terminal
50: Conductor

Claims (3)

A dielectric substrate;
A line conductor disposed on one main surface or inside of the dielectric substrate;
A ground conductor formed with a slot functioning as an antenna capable of transmitting and receiving a high-frequency signal, disposed so that one main surface is in contact with the other main surface of the dielectric substrate;
A high-frequency component containing a high-frequency circuit having a high-frequency signal terminal for at least one of input and output of the high-frequency signal, disposed adjacent to the slot on the other main surface side of the ground conductor;
A conductor having one end connected to the high-frequency signal terminal and functioning as an antenna capable of transmitting and receiving the high-frequency signal;
The line conductor is disposed so as to traverse the slot, and is electromagnetically coupled to the slot and constitutes a high-frequency line that transmits the high-frequency signal together with the dielectric substrate and the ground conductor. ,
The high-frequency signal terminal is disposed on the main surface opposite to the side facing the ground conductor in the high-frequency component,
The conducting wire is a bonding wire, the conducting wire is disposed on the other main surface side of the ground conductor so as to cross the slot, and the high-frequency circuit and the high-frequency line are electromagnetically connected. A connection structure between a high-frequency circuit and a high-frequency line. The conducting wire has a non-grounded end with the other end floating away from the ground conductor and having an electrical length of (2n-1) / 4 times the wavelength of the high-frequency signal (n is a natural number) The connection structure between the high-frequency circuit and the high-frequency line according to claim 1. An island conductor insulated from the ground conductor is disposed on the opposite side of the high frequency signal terminal across the slot on the other main surface of the dielectric substrate, and the conductor is connected to the island conductor. The connection structure between the high-frequency circuit and the high-frequency line according to claim 1, wherein the other end is connected.

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