JPH0724289B2 - High frequency hybrid integrated circuit - Google Patents

Description

The present invention relates to a hybrid integrated circuit, and more particularly to stabilization of circuit operation,
The present invention also relates to a high-frequency hybrid integrated circuit that enables miniaturization and high density of the circuit.

[Conventional technology]

Conventionally, this type of high-frequency hybrid integrated circuit forms an asymmetrical strip line by a line conductor formed on one surface of a dielectric substrate and a ground conductor formed on the other surface of the dielectric substrate. A hybrid integrated circuit that carries out some kind of circuit operation (oscillation, amplification, etc.) by mounting active and passive elements on the line conductor, and covers the inside with a box-shaped dielectric cap having a lower opening. It was tightly sealed.

[Problems to be solved by the invention]

In the above-described conventional high-frequency hybrid integrated circuit, when it is necessary to configure the circuit with a low-impedance line, it is necessary to widen the line width of the line conductor. Therefore,
In this case, the area of the entire circuit also becomes large. Also, if line conductors that are excited in opposite phase are wired close to each other, electric field coupling will occur, causing abnormal oscillation due to feedback.In such a case, the line conductor spacing should be reduced. Need to be wide. For these reasons, it has been difficult to reduce the circuit size and increase the density.

[Means for solving problems]

The high frequency hybrid integrated circuit of the present invention is a high frequency hybrid integrated circuit in which a line conductor pattern is formed on an element mounting surface of a dielectric substrate and is covered with a dielectric cap to face the line conductor pattern of the dielectric cap. The conductive layer is formed on the protruding portion, and is connected to the lower ground conductor of the dielectric substrate.

〔Example〕

 Next, the present invention will be described with reference to the drawings.

FIG. 1 is a partial sectional view of an embodiment of the present invention. In FIG. 1, line conductor patterns 3a and 3b are formed on one surface of a dielectric substrate 1, and a ground conductor 2 is formed on the lower surface of the substrate 1. Further, a protrusion 5 is formed on the inner surface of the box-shaped dielectric cap 4 having a lower opening at a portion facing the line conductor pattern 3b, and a ground conductor 6 is formed on the surface of the protrusion 5. . As shown in FIG. 2, one end of the ground conductor 6 is connected to the ground conductor 2 of the dielectric substrate 1 by a brazing material 7 such as solder. The electric field of the strip line 3b where the ground conductor 6 is formed is formed between the line conductor 3b and the ground conductor 2 and between the line conductor 3b and the ground conductor 6 as shown in FIG. 3 (b). Thus, when the strip line does not have the ground conductor 6, the impedance of the strip line can be reduced in the same circuit area as in FIG. 3 (a). For example, when an alumina substrate having a thickness of 0.635 mm is used as the dielectric substrate 1 and the width of the line conductor pattern 3b is set to 0.6 mm, the protrusion 5 is formed so that the distance between the line conductor 3b and the ground conductor 6 becomes 0.6 mm. , The line impedance is about
35 Ω, without the ground conductor 6 on the inner surface of the cap (approx.
The line impedance can be reduced by about 15Ω compared to 50Ω).

FIG. 4 is a partial sectional view of the second embodiment of the present invention. If the line conductor 8 and the line conductor 9 are, for example, 50Ω lines on the dielectric substrate 1, for example, an alumina substrate having a thickness of 0.65 mm,
The line conductors 8 and 9 are arranged close to each other by about 0.6 mm and are excited in opposite phases. The dielectric cap 4 is
A protrusion 5 is formed on the line conductors 8 and 9 and a ground conductor 6 is formed on the surface of the protrusion 5. One end of the ground conductor 6 is connected to the ground conductor 2 on the lower surface of the substrate by a brazing material 7 such as solder. In the structure of this embodiment, the electric field coupling as shown in FIG. 5 (a) in the case where there is no ground conductor 6 on the cap inner surface protrusion is shielded by the ground conductor 6 as shown in FIG. 5 (b). No longer join,
Abnormal oscillation due to feedback can be prevented.

FIG. 6 is a partial sectional view of the third embodiment of the present invention. In FIG. 6, the ground conductor 6 facing the line conductor 10 on the dielectric substrate 1 is provided inside the dielectric layer without being exposed to the inner surface of the dielectric cap 4, and is connected to the line conductor 10. There is no need to worry about short circuits.

〔The invention's effect〕

As described above, according to the present invention, a part of a circuit composed of an asymmetrical strip line is provided on one surface of a dielectric substrate at a facing portion of a box-shaped dielectric cap which is placed on the substrate. By using a strip line structure that is approximately symmetrical, a low impedance line can be realized without increasing the circuit area. Further, there is also an effect that abnormal oscillation due to coupling between lines due to high density of the circuit can be prevented.

[Brief description of drawings]

FIG. 1 is a partial sectional view of an embodiment of the present invention, and FIG.
Fig. 3 is a sectional view taken along the line AA, Figs. 3 (a) and 3 (b) are views showing the electric field distribution of the embodiment of Fig. 1, and Fig. 4 is a partial sectional view of the second embodiment of the present invention. 5 (a) and 5 (b) are views showing the electric field distribution in the embodiment of FIG. 4, and FIG. 6 is a sectional view showing a modification of the conductor layer on the inner surface of the dielectric cap. 1 ... Dielectric substrate, 2 ... Ground conductor on the bottom of the substrate, 3a, 3b,
8,9,10 ...... Line conductor, 4 ... Dielectric cap, 5 ... Cap inner wall hole, 6 ... Cap inner wall projection conductor, 7 ... Brazing material.

Claims (1)

[Claims] 1. A high-frequency hybrid integrated circuit in which a line conductor pattern is formed on an element mounting surface of a dielectric substrate and is covered with a dielectric cap, and in a portion opposed to the line conductor pattern of the dielectric cap. A hybrid integrated circuit for high frequency, comprising: a protrusion, wherein a conductor layer connected to the lower ground conductor of the dielectric substrate is formed on the protrusion.