JP5740253B2 - High frequency device - Google Patents

Description

  Embodiments described herein relate generally to a high-frequency device.

  A conventional high-frequency semiconductor device such as a high-frequency package has a high-frequency semiconductor element such as an FET and a matching circuit.

  The matching circuit includes a matching transmission line and a plurality of chip capacitors. The transmission line is provided on the surface of the dielectric substrate, and the chip capacitor is constituted by another dielectric substrate and electrodes provided on the front and back surfaces of the dielectric substrate, respectively.

  Therefore, a matching circuit is configured by mounting them on a single metal plate and electrically connecting the transmission line to each chip capacitor. The dielectric substrate on which the transmission line is formed and the chip capacitor are mounted on a metal plate by gold tin (AuSn) solder.

  By the way, as the frequency used increases, the parasitic capacitance, parasitic inductance, and other things that do not need to be considered in the lumped constant circuit increase. Use.

  When a circuit is configured with distributed constants on a dielectric substrate on which a matching circuit is formed, the wavelength shortening rate is determined by the dielectric constant of the dielectric substrate, and the size of the circuit is determined according to the wavelength. Therefore, when the matching circuit is configured by the distributed constant circuit as described above, when the wavelength is long, the circuit scale increases and the area occupied by the matching circuit also increases. Since the resonance frequency of the high frequency package is determined by the wavelength to be handled, it is not possible to construct a large circuit without limitation. Further, there is a problem that cracks and peeling occur after attachment due to the difference in coefficient of linear thermal expansion between the material of the package and the material of the matching device, and the ratio of these increases in proportion to the area.

  The present invention provides a high-frequency device in which a circuit can be configured relatively large, can be easily manufactured and adjusted, and a circuit that is desired to be downsized can be formed in a small size.

JP 2010-259005 A

  The present invention provides a high-frequency device in which a circuit can be configured relatively large, can be easily manufactured and adjusted, and a circuit that is desired to be downsized can be formed in a small size.

A high-frequency device according to one embodiment includes a first dielectric substrate having a first electrode on the back surface, a second electrode on the back surface, a second electrode on the back surface, and a notch on the surface. And a second dielectric substrate made of a material having a lower dielectric constant than the first dielectric substrate, and formed on the first dielectric substrate at the position of the notch. The spiral line and the first dielectric substrate are formed at the position of the notch, connected to the spiral line, and distributed by the first electrode and the first dielectric substrate. A surface electrode forming a capacitor by a constant circuit, a transmission line formed on the second dielectric substrate, and a conductive member connecting the transmission line and the spiral line are provided.

It is a perspective view of the high frequency device concerning a 1st embodiment. It is a perspective view for demonstrating the manufacturing method of 1st Embodiment. It is a perspective view of the high frequency device concerning a 2nd embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

<First Embodiment>
A perspective view of the high-frequency device of the first embodiment is shown in FIG. This embodiment is an example of a matching device in which an open stub is formed by a distributed constant circuit. In FIG. 1, reference numeral 11 denotes a first dielectric substrate having a rectangular plate shape and having a high dielectric constant, and a back electrode 12 is formed on one surface on the back surface. On the first dielectric substrate 11, a second dielectric substrate 14 having the same shape and having a back electrode 13 formed on the back surface is provided. The dielectric constant of the second dielectric substrate 14 is lower than the dielectric constant of the first dielectric substrate 11.

  A transmission line 15 having a predetermined width is formed on the second dielectric substrate 14, a part of which is wide, and this part forms the matching circuit unit 16. A microstrip line is formed by the transmission line 15, the second dielectric substrate 14, and the back electrode 13 thereof.

  A portion of the second dielectric substrate 14 is cut out in a U-shape to form a cutout portion 17, and the first dielectric substrate 11 is exposed at this portion. A surface electrode 18 is provided on the first dielectric substrate 11 corresponding to the notch 17. The transmission line 15 is connected to the surface electrode 18 by a lead wire 19 which is a conductive member, for example, a gold wire, at a projection partway along the transmission line 15. An open stub based on a distributed constant circuit is formed by the front electrode 18, the first dielectric substrate 11, and the back electrode 12.

  The thickness of the first dielectric substrate 11 is about 0.5 mm to 1 mm, for example, and the thickness of the second dielectric substrate 14 is about 0.2 mm to 0.6 mm, for example.

  The relative dielectric constant of the first dielectric substrate 11 is, for example, about 20 to 10,000, and the relative dielectric constant of the second dielectric substrate 14 is, for example, about 2 to 10. For example, alumina is used as the second dielectric substrate, and the dielectric constant of the material of the first dielectric substrate 11 can be changed by changing the mixing ratio of the mixture.

  The first dielectric substrate 11 is preferably made of a dielectric material having a high dielectric constant in consideration of the shape of the surface electrode 18 formed thereon. This is because by using such a dielectric substrate, the shape of the surface electrode 18 forming the open stub can be reduced by the effect of shortening the wavelength.

  The second dielectric substrate 14 is preferably made of a dielectric material having a low dielectric constant in consideration of the size of the transmission line 15 and the matching circuit portion 16 formed thereon. This is because if the dielectric substrate is made of a very high dielectric material, the size of the transmission line 15 and the matching circuit portion formed on the dielectric substrate becomes small, making it difficult to manufacture.

  By using a dielectric material having a low dielectric constant, the impedance of the transmission line 15 can be lowered, or the width of the transmission line 15 having a desired impedance can be made relatively wide.

  The matching circuit having the above-described configuration can be used as an input matching circuit or an output matching circuit of an FET chip. In such a case, the dimensions of the surface electrode 18 formed on the first dielectric substrate 11, the width of the transmission line 15 formed on the second dielectric substrate 14, and the matching circuit unit 16 are adjusted. Then, it is configured to match the characteristic impedance of the FET chip.

  Next, a method for manufacturing the matching device of this embodiment will be described. As shown in FIG. 2, the surface electrode 18 is formed on the surface of the first dielectric substrate 11 having a rectangular plate shape, and the back electrode 12 is formed on the back surface of the dielectric substrate 11. The front electrode 18 and the back electrode 12 are formed by a method such as vapor deposition or sputtering.

  On the other hand, the square plate-like second dielectric substrate 14 is formed by forming the back electrode 13 on the back surface thereof by, for example, vapor deposition or sputtering. The dielectric substrate 14 has a notch 17 formed by cutting out one corner near the surface electrode 18 in a U-shape. Further, the transmission line 15 and the matching circuit unit 16 are formed on the surface of the second dielectric substrate 14 by a method such as vapor deposition or sputtering.

  Next, the second dielectric substrate 14 is laminated on the first dielectric substrate 11 and fixed. At this time, the second dielectric substrate 14 is laminated and fixed so that the surface electrode 18 formed on the first dielectric 11 is exposed from the notch 17. Note that the first dielectric substrate and the second dielectric substrate 14 are fixed by, for example, solder, adhesive, sintering, or the like.

  Finally, the protrusion of the transmission line 15 and the surface electrode 18 are connected by a lead wire 19. In this way, the matching device of the first embodiment is manufactured.

  According to this embodiment, it is possible to obtain a high-frequency device in which a circuit can be configured relatively large, can be easily manufactured and adjusted, and a circuit that needs to be downsized can be formed small. According to this embodiment, a small matching device in which an open stub is formed by a distributed constant circuit can be obtained.

<Second Embodiment>
Next, a second embodiment will be described based on FIG. This embodiment is different from the matching device of the embodiment shown in FIG. 1 in that a surface electrode constituting a capacitor by an inductance and a lumped constant circuit is formed on a high dielectric substrate by a distributed constant circuit. is there. Other points have the same configuration as that of the first embodiment and are manufactured by the same method.

  In FIG. 3, a back electrode 22 is provided on the back surface of the first dielectric substrate 21, and a second dielectric substrate 24 having a back electrode 23 provided on the back surface is fixed thereon. The first dielectric substrate is made of a dielectric material having a high dielectric constant, and the second dielectric 24 is made of a dielectric material having a low dielectric constant. On the second dielectric substrate 24, a transmission line 25 and a matching circuit unit 26 connected to the transmission line 25 are formed as in the embodiment of FIG.

  The relative dielectric constant of the first dielectric substrate 21 is, for example, about 20 to 10,000, and the relative dielectric constant of the second dielectric substrate 24 is, for example, about 2 to 10. For example, alumina is used as the second dielectric substrate 24, and the dielectric constant of the material of the first dielectric substrate 11 can be changed by changing the mixing ratio of the mixture.

  The second dielectric substrate 24 has a U-shaped notch 27. On the first dielectric substrate 21 corresponding to the notch 27, a spiral line 28a constituting an inductance and a surface electrode 29 are provided. The spiral line 28a is connected to the protrusion of the transmission line 25 and, for example, a lead wire 29a that is a gold wire, and the spiral line 28a and the surface electrode 28 are connected to a lead wire 29b that is a gold wire, for example. .

  The spiral line 28a, the first dielectric substrate 21 and the back electrode 22 form an inductance by a distributed constant, and the front electrode 28, the first dielectric substrate 21 and the back electrode 22 form a capacitor by a lumped constant circuit. Has been.

  According to the second embodiment, since the spiral line 28a and the surface electrode 28 are formed on the first dielectric substrate 21 having a high dielectric constant, the matching circuit that obtains a predetermined inductance and capacitance is miniaturized. A device is obtained.

  By the way, in the description of the above embodiment, the matching device has been described. However, the present invention is not limited to matching devices. For example, in the embodiment shown in FIG. 3, if the surface electrode 18 is held in a DC voltage, it can be used as a bias device and can be generally applied to a high-frequency device.

  As described above, a component that is desired to be small in size (a component that can be formed small) is configured on the first dielectric having a high dielectric constant, and a component that is relatively large in size (a component that can be formed large). ) Is suitably formed on a second dielectric substrate having a low dielectric constant, so that it is relatively easy to manufacture and a small high-frequency device can be obtained as a whole.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

11, 21... First dielectric substrate,
12, 13... Back electrode,
14, 24... Second dielectric substrate,
15, 25 ... Transmission line,
16, 26... Matching circuit part,
17, 27... Notch,
18, 28... Surface electrode,
19, 29a, 29b... Lead wire,
28a ... spiral line.

Claims (2)

A first dielectric substrate having a first electrode on the back surface;
The second dielectric layer is provided on the first dielectric substrate, has a second electrode on the back surface, has a notch on the front surface, and is made of a material having a dielectric constant lower than that of the first dielectric substrate. A dielectric substrate,
A spiral line formed on the first dielectric substrate and at the position of the notch;
A capacitor formed by a distributed constant circuit is formed on the first dielectric substrate at the position of the notch, connected to the spiral line, and formed by the first electrode and the first dielectric substrate. A surface electrode to be
A transmission line formed on the second dielectric substrate;
A high-frequency device comprising the transmission line and a conductive member that connects the spiral line. High-frequency device according to claim 1, wherein a matching circuit section in the middle of the transmission line.

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