JPH07240609A - Mounting structure for fet chip in microwave hybrid integrated circuit - Google Patents

Abstract

PURPOSE:To provide the mounting structure of an FET chip with less insertion loss and reflection loss and reduced in manufacturing man-hours. CONSTITUTION:The FET chip 1 is mounted and fixed on a transmission conductor 5, the source electrode 4 of the FET chip 1 is connected to the transmission conductor 5 by a wire 6 and a drain electrode 3 is connected to a ground conductor 9 in terms of a high frequency by connecting the drain electrode 3 to a 1/4 wavelength open stub 7 attached on the dielectric substrate 8 of a strip line by the wire 13. Also, by connecting the transmission conductor 5 to the ground conductor 9 by using a high impedance line 10, the DC round of the FET chip 1 is provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a mounting structure of an FET chip in a microwave hybrid integrated circuit and a parallel type high frequency switch constructed by using the mounting structure.

In a microwave hybrid integrated circuit, when mounting an FET (Field Effect Transistor) chip, it is necessary to suppress an increase in insertion loss and reflection loss or an increase in the number of manufacturing steps due to the mounting structure of the FET chip. To be done.

[0003]

2. Description of the Related Art FIG. 6 shows a conventional example of a parallel type high frequency switch circuit using an FET chip formed by a microwave hybrid integrated circuit. In this microwave hybrid integrated circuit, components such as an FET chip and a capacitor are mounted on a dielectric substrate forming a microstrip line to form a circuit. When making a parallel type high frequency switch circuit with this microwave hybrid integrated circuit, FIG.
As shown in, the drain electrode 3 of the FET chip 1 is connected to the transmission line (transmission conductor) 5, and the source electrode 4 is connected to the ground conductor 9 so as to be grounded. In such a connection, when the FET chip 1 is turned on, a series resonance circuit as shown in FIG. 6 (c) is propagated through the transmission line in the form of being inserted in parallel with the transmission line as an equivalent circuit. The reflected signal is reflected at the point A, while when the FET chip 1 is turned off, the signal propagates through the point A. The capacitor C and the inductor L in FIG. 6C are formed by the inductance and capacitance of a connecting wire, which will be described later.

A mounting structure of the FET chip 1 for forming the above-mentioned high frequency switch circuit is shown in FIG. 6 (a).
The FET chip 1 has a gate electrode 2, a drain electrode 3, and a source electrode 4 on its front surface side, and the source electrode 4 is connected (conducted) from the front surface of the chip to the back surface of the chip through a via hole 12. The microstrip line has a dielectric substrate 8 at a position where the FET chip 1 is attached.
And the transmission line 5 are divided into two, and the FET chip 1
Is placed on the ground conductor 9 in the divided portion, and the source electrode 4 thereof is electrically connected to the ground conductor 9 through the via hole 12. The drain electrode 3 is connected to each transmission line 5 of the microstrip line divided into two by a wire 6 '.

In this conventional example, the source electrode 4 of the FET chip 1 and the ground conductor 9 are connected by the via hole 12, but instead of this, a wire is provided between the source electrode 4 and the ground conductor 9 on the chip surface. It may be connected directly with.

[0006]

In the conventional microwave hybrid integrated circuit, in order to mount the FET chip 1, the transmission line 5 of the microstrip line is divided and the FET chip 1 is inserted into the divided portion. Therefore, it is necessary to use the wire 6 ′ for the connection between the drain electrode 3 and the transmission line 5. For this reason, particularly in a high frequency band, signal insertion loss and reflection loss are deteriorated due to the inductance component of the wire 6 '. In addition, FET
In order to use the substrate with the source grounded, it is necessary to divide the dielectric substrate 8 into two and form a via hole, which increases the number of manufacturing steps.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a mounting structure of an FET chip which has less insertion loss and reflection loss and requires less manufacturing steps.

[0008]

The principle of the present invention will be described below with reference to FIG. In order to solve the above problems,
In the present invention, the mounting of the FET chip (1) in the microwave hybrid integrated circuit configured by using the strip line in which the ground conductor (9) is attached to the rear surface of the dielectric substrate (8) and the transmission conductor (5) is attached to the front surface. The structure is such that the FET chip (1) is mounted and fixed on the transmission conductor (5),
The source electrode (4) of this FET chip (1) is connected to the transmission conductor (5) by a wire (6), and the drain electrode (3)
Connect the drain electrode (3) to the ground conductor (9) at high frequency by connecting the wire electrode (13) to the quarter-wave open stub (7) mounted on the stripline dielectric substrate (8). In addition, the transmission conductor (5) is connected to the ground conductor (9) by using the high impedance line (10) to provide a DC ground of the FET chip (1). A mounting structure for a FET chip in an integrated circuit is provided.

Further, in the present invention, in the above mounting structure, instead of connecting the source electrode of the FET chip to the transmission conductor with a wire, the source electrode of the FET chip is guided from the front surface of the chip to the back surface of the chip by a via hole. The structure may be such that it is connected to the transmission conductor.

In the present invention, instead of connecting the drain electrode to the ground conductor with a quarter wavelength open stub in the above mounting structure, the drain electrode is provided via a via hole provided on the dielectric substrate. The structure may be such that it is connected to the ground conductor. Further, in this structure, the high impedance line may be excluded.

[0011]

According to the mounting structure of the present invention, the transmission conductor and the FET
Since the connection between the chips is made by a wire or via hole between the source electrode and the ground conductor, the above wire is used as compared with the case where the FET chip is arranged by dividing the conventional transmission conductor and the wire is connected between them. Even in this case, the wire agency is shortened, so that the influence of the wire can be suppressed to a small level.

[0012]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows an embodiment of a parallel type high frequency switch circuit using a mounting structure of an FET chip in a microwave hybrid integrated circuit of the present invention. FET chip 1
Has a gate electrode 2, a drain electrode 3, and a source electrode 4 on the surface of the chip as described above. In this embodiment, the microstrip line is not divided into two, the FET chip 1 is mounted and fixed on the transmission line 5, and the source electrode 4 is electrically connected to the transmission line 5 by the wire 6. Along with this, a quarter wavelength open stub 7 is provided on the dielectric substrate 8 and the drain electrode 3 of the FET chip 1 is electrically connected to the quarter wavelength open stub 7 by the wire 13, whereby the drain electrode 3 is formed. The ground conductor 9 is grounded in a high frequency (RF) manner. The gate electrode 2 is connected to the DC power supply line 11 for controlling the gate voltage with a wire 14. Further, the transmission line 5 is connected to the ground conductor 9 via the high impedance line 10 for high frequency, thereby obtaining a direct ground GND of the source electrode 4 of the FET chip 1.

With this connection, as shown in FIG. 2, the source electrode 4 of the FET is connected to the transmission line 5 and the drain electrode 3 is grounded in terms of high frequency components in terms of electric circuit. It is possible to realize a high frequency switch circuit using a series resonance circuit formed by the inductance and capacitance of the wire 6 of the drain electrode 3 and the quarter wavelength open stub 7.

With such a mounting structure, the length of the wire 6 connecting the source electrode 4 and the transmission line 5 or the wire 13 connecting the drain electrode 3 and the quarter-wave open stub 7 can be reduced to the conventional length. Source electrode 4 and transmission line 5
Since it is possible to make the wire 6'shorter than the wire connecting it, it is possible to reduce the inductance components thereof, and thus it is possible to suppress deterioration of insertion loss and reflection loss.

Various modifications are possible in carrying out the present invention. For example, in the above-described embodiment, the source electrode 4 of the FET chip 1 and the transmission line 5 are electrically connected by the wire 6, but the present invention is not limited to this, and as shown in FIG. If the source electrode 4 on the front surface of the chip is structured to be guided to the back surface of the chip by the via hole 12 and is directly electrically connected to the transmission line 5 on the back surface of the chip, the wire 6 can be removed. Therefore, it becomes possible to further reduce the insertion loss and the reflection loss.

The connection between the drain electrode 3 and the ground conductor 9 is not limited to the quarter wavelength open stub 7,
It may be a via hole. FIG. 4 shows this embodiment, in which the inductance element 15 is formed on the dielectric substrate 8.
Is attached, the drain electrode 3 is electrically connected to the inductance element 15 by the wire 13, and the inductance element 7 is grounded to the ground conductor 9 through the via hole 15.

Of course, as shown in FIG.
The source electrode 4 of the chip 1 may be electrically connected to the transmission line 5 through the via hole 12, and the drain electrode 3 may be grounded to the ground conductor 9 through the inductance element 15 and the via hole 16.

In the structures shown in FIGS. 4 and 5, the direct current ground of the FET chip 1 is obtained by grounding the drain electrode 3 to the ground conductor 9, so that the direct current on the source electrode 4 side is reduced. It is also possible to omit the high impedance line 10 for taking a proper ground.

Although the above-mentioned embodiment is a case where the mounting structure of the FET chip of the present invention is used in a parallel type high frequency switch circuit, the present invention is not limited to this, and in a microwave hybrid integrated circuit, By adopting a configuration in which the gate electrode is controlled by the same mounting structure, it can be used in a filter circuit, a variable attenuator, or the like.

[0020]

As described above, according to the present invention, it is not necessary to divide the transmission line on the way to connect it with a wire in order to mount the FET chip, and the insertion loss and the reflection loss due to the wire are eliminated. The increase can be suppressed. Further, since it is not necessary to divide the dielectric substrate or form a via hole to obtain the ground of the FET chip,
Therefore, the number of manufacturing steps can be reduced.

[Brief description of drawings]

FIG. 1 is a diagram showing a parallel type high frequency switch circuit configured by using a mounting structure of an FET chip in a microwave hybrid integrated circuit as an embodiment of the present invention.

FIG. 2 is a diagram showing an electric circuit of a parallel type high frequency switch circuit according to an embodiment.

FIG. 3 is a diagram showing another embodiment of the present invention.

FIG. 4 is a diagram showing another embodiment of the present invention.

FIG. 5 is a diagram showing still another embodiment of the present invention.

FIG. 6 is a diagram showing a conventional example.

[Explanation of symbols]

 1 FET Chip 2 Gate Electrode 3 Drain Electrode 4 Source Electrode 5 Transmission Line 6, 6 ', 13, 14 Wire 7 1/4 Wave Open Stub 8 Dielectric Substrate 9 Grounding Conductor 10 High Impedance Line (for DC Ground) 11 DC Power line 12, 16 Via hole 15 Inductance element

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location H01L 21/8232 21/338 29/812 H01P 1/15

Claims (5)

[Claims] 1. A mounting structure of an FET chip in a microwave hybrid integrated circuit, which is configured by using a strip line in which a ground conductor (9) is attached to the back surface of a dielectric substrate (8) and a transmission conductor (5) is attached to the front surface. Then, the FET chip (1) is mounted and fixed on the transmission conductor, and the source electrode (4) of the FET chip is connected to the wire (6).
Connected to the transmission conductor (5) with the drain electrode (3) mounted on the dielectric substrate of the strip line by 1/4.
By connecting the wavelength open stub (7) with the wire (13), the drain electrode is connected to the ground conductor at high frequency, and the transmission conductor is connected to the ground conductor by using the high impedance line (10). Thus, the mounting structure of the FET chip in the microwave hybrid integrated circuit is characterized in that the direct current ground of the chip FET is provided. 2. A structure in which the source electrode of the FET chip is connected to the transmission conductor by a wire, instead of being connected to the transmission conductor by a wire, the source electrode of the FET chip is led from the chip surface to the back surface of the chip by a via hole and connected to the transmission conductor. The mounting structure of the FET chip in the microwave hybrid integrated circuit according to claim 1, wherein. 3. The drain electrode is connected to the ground conductor via a via hole provided on the dielectric substrate, instead of connecting the drain electrode to the ground conductor with the quarter-wave open stub. 3. The mounting structure of the FET chip in the microwave hybrid integrated circuit according to claim 1, wherein the mounting structure is a structure. 4. The mounting structure of the FET chip in the microwave hybrid integrated circuit according to claim 3, wherein the high impedance line is removed. 5. The FET according to any one of claims 1 to 4.
A parallel type high frequency switch characterized in that an FET chip is mounted on a microwave hybrid integrated circuit by using a chip mounting structure.