JPH03249803A - Package for micro wave ic - Google Patents

Abstract

PURPOSE:To constitute a micro wave receiver circuit with the high degree of freedom by forming a passive circuit which integrally constitutes a part of a micro wave circuit near the positions of the conductors of a dielectric substrate which forms the conductors such as a micro strip line and a signal transmission line, both of which are contained in a micro wave circuit on a surface. CONSTITUTION:The passive circuit containing an image frequency removal filter 8 for constituting a low noise down converter by respective IC mounted on a metallic conductive plate 2 and a trimming conductor 9, the strip line 10a and the signal transmittion line 10b for transmitting a signal between respective IC are integrally formed by patterning the metallic conductive film by Au vapor deposition. Thus, the micro wave receiver circuit can be constituted with a high degree of freedom.

Description

[Detailed Description of the Invention] The present invention relates to a package for microwave integrated circuits, and in particular to miniaturization and weight reduction of microwave communications, satellite broadcasting receivers, etc.
The present invention relates to a package structure that is effective for high conversion.

In recent years, microwave integrated circuits have been rapidly used in communication applications, including front-end circuits of satellite broadcasting receivers. Consideration of its use in fields such as information processing is being actively pursued.

Among them, monolithic microwave integrated circuits (MMICs) using GaAs as substrates are becoming highly invertible, as semiconductor devices with low noise characteristics such as HEMTs are being put into practical use.

It is attracting attention as a future device due to its low cost.

Figure 2 is a diagram showing the circuit system of the front end part of a satellite broadcasting receiver. In the figure, 21 is a waveguide coaxial conversion circuit for converting the signal input from the antenna to the waveguide, 22 is a low-noise amplifier circuit configured using GaAsFET, and 23 is a λ/4 open star. 24 is a mixer circuit, 25 is a local oscillation circuit, and 26 is an intermediate frequency amplification circuit.

However, as receivers in satellite broadcasting receiving systems become more widespread in ordinary homes, there is a need to improve efficiency, productivity, and reduce costs, especially for the circuit system located at the first stage, which consists of the above-mentioned configuration. As a countermeasure for this, attempts have been made to monolithically form each component of the front end section onto one chip.

However, all the constituent elements of the above front end are
Currently, there are many problems with chipping in terms of the characteristics required of each element, and therefore, if integration is to be implemented, the low-noise amplifier circuit 22. The image frequency removal filter 23° mixer circuit 24 and the intermediate frequency layer 1i circuit 26 are integrated into one chip, and integration in this range is considered to be relatively feasible, and efforts are being actively made to integrate the MMIC. There is.

However, partial MMIC of such low noise amplification circuits, image rejection filters, mixer circuits, and intermediate frequency amplification circuits
In the current situation, the above image removal filter 23
Since it is constructed by a combination of λ/4 open stubs etc. on a GaAs substrate, it requires a large area to obtain a sufficient image suppression effect, and if it was constructed on a GaAs substrate, it would be disadvantageous in terms of cost. There is a problem.

Further, when MMIC is used, reliability and productivity can be improved, but conversely, there is a drawback that the best performance cannot be brought out because fine adjustment of the interstage matching circuit cannot be performed sufficiently by trimming.

The present invention is intended to improve these problems in view of the above points, and provides a package with a high degree of freedom for mounting microwave ICs.

The microwave IC package according to the present invention is constructed by providing a passive circuit on a part of a pancasing base material made of a dielectric material such as ceramic. is incorporated in a desired position of the packaging stem, and the passive circuit is a microstrip life coupler.

It consists of an image frequency removal filter made of a sector-shaped λ/4 open stub, etc., and a conductor region for trimming. Furthermore, a low-noise amplification IC, mixer IC, intermediate frequency amplification IC, etc. are attached to the packaging stem, and an image frequency removal filter section as a passive circuit is integrally formed on the packaging base material to form a microwave IC module. Configure.

According to the microwave IC package of the present invention, since the image frequency rejection filter, which requires a relatively large occupied area, is constructed using a part of the packaging stem material, a sufficient image suppression ratio can be ensured. It is possible to easily meet the demand for increasing the area occupied by the filter so that the area occupied by the filter can be increased, and by completely converting it into a single chip, it is inevitable that the chip cost will rise more than when converting it to an MMIC.

Furthermore, when looking at the overall volume of the IC module, the increase in stem volume due to the addition of the filter is only MM.
While maintaining the same volume as when installed as an IC chip, it is possible to significantly improve performance and cost. In addition, by providing a small conductor layer for trimming when forming passive circuits such as filters, trimming can be used to connect the low-noise amplifier IC and mixer IC through an image frequency removal filter to achieve matching. Fine tuning of the alignment can be made.

亥JLfi Hereinafter, a microwave IC package according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1a is a plan view of the implementation form of the front end part of a satellite broadcast receiving system, and FIG. A case is shown in which chips such as LNAIC), mixer IC, and intermediate frequency amplification IC (IFAMP IC) are mounted.

In the figure, an IC packaging stem 1 is constructed by using a metal conductor plate 2 as a support substrate, and a dielectric substrate 3 made of ceramic or the like whose back surface is metallized is adhered onto the metal conductor plate 2. Note that the metal plate 2 serves as a ground plane for the package.

The dielectric substrate 3 has holes 4a and 4b that pass through the substrate.

4c is processed, and circuit elements for configuring the front end part of the satellite broadcast receiving system, namely, a low-noise amplifier IC 5, a mixer IC 6, and an intermediate frequency amplifier IC 7 are fitted into each of the above-mentioned members, and each IC is mounted on the metal conductor plate 2. It is mounted on the ground and grounded. On the surface of the dielectric substrate 3, a passive circuit including an image frequency removal filter 8 and a trimming conductor 9 for constructing a low-noise down converter with each of the ICs mounted on the metal conductor plate 2, and a strip line. A signal transmission line 10b for transmitting signals between the IC 10a and each of the above-mentioned ICs is integrally formed by patterning a metal conductor film by Au vapor deposition, Au plating, or the like.

The metal conductor film for configuring the passive circuit including the image frequency removal filter 8 and the trimming conductor 9, especially the image frequency removal filter 8, is a band rejection filter made of a microtrip line coupler or a fan-shaped λ/4 open stub. Designed as.

A passive circuit including the image frequency removal filter 8 and the trimming conductor 9 is also provided near the signal transmission line 10, and is connected to a strip line as necessary to enable the passive circuit to function. It is used to expand the scope of use.

Furthermore, by forming the image frequency removal filter 8 in a fan shape as in this embodiment, the absorption band for incoming microwaves can be wider than when forming it in a rectangular shape. You can get a filter effect.

Since the filter structure of this embodiment uses the surface area of the dielectric substrate 3, the restrictions on the occupied area are significantly relaxed compared to the case where it is formed on a GaAs substrate, and a filter with excellent performance can be obtained.

In particular, in the sector-shaped λ/4 open stub structure, the area occupied by the filter is approximately 2×5+u+'', which is only an approximately 20% increase in the area of the entire stem, which is 12×5 mm, and a small and highly efficient filter can be obtained.

The trimming conductor 9 is formed on the surface of the dielectric substrate 3 and in the vicinity of the fan-shaped image frequency removal filter 8, and connects the low noise amplification IC 5 and mixer IC 6 via the image frequency removal filter 8. This is used for trimming when matching is performed, and fine adjustment of inter-stage matching is achieved.

The dielectric substrate 3 also has terminals for supplying power and terminals for inputting and outputting signals with an external circuit, that is, R
F signal input terminal 11. IF signal output terminal 12. Local signal input terminal 13. and a DC bias terminal 14 are attached. Each of these terminals 11 to 14, each IC5 to
7 and signal transmission lines 10a to 10C are connected by wires or the like so as to function as a satellite broadcast receiving circuit.

The receiving circuit mounted on the metal conductor plate 2 is protected by covering the upper surface with a cap seal 15 on a dielectric substrate 3.
A support material 16 is inserted around the periphery, and the upper part of this support material is covered with a cap seal 15. The support material 16 is made of a dielectric material, and holds the terminals 11 to 14 formed on the dielectric substrate 3 by sandwiching them therein.
Metallization is applied to the outer periphery of the dielectric, and a portion thereof is connected to a metal conductor plate 2 and grounded.

A microwave IC module was created by mounting each IC as shown in FIG. As a result, a low-noise down converter with a good image suppression ratio was obtained.

As described above, according to the IC packaging stem of the present invention, it is possible to configure a microwave receiving circuit with a high degree of freedom without placing any burden on the GaAS semiconductor substrate for microwave reception. Therefore, it is possible to obtain a circuit system having a passive circuit such as an image frequency removal filter having particularly high performance. Incidentally, by integrally forming the passive circuit with the packaging stem, there is almost no increase in area or complexity of the process.

[Brief explanation of drawings]

FIG. 1a is a plan view showing one embodiment of the present invention, FIG. 1 is a sectional view of the same embodiment, and FIG. 2 is a block diagram of a conventional satellite broadcasting receiver front end. 1 - packaging stem, 2 - metal conductor. 3-...Dielectric substrate, 4a-4c-holes, 5-L
NA I G. 6...-mixer IC, 7...I FAMP IC
. 8--Image frequency removal filter. 9-) Rimming conductor, 10a to 10cm - metal conductor. 11-14 one terminal, 15-.-cap sealing material.

Claims (3)

[Claims] (1) In a package for mounting a microwave circuit, a dielectric substrate on which conductors such as microstrip lines, signal transmission lines, etc. included in the microwave circuit are formed, is integrally placed in the vicinity of the conductor position. A package for a microwave IC, characterized in that a passive circuit constituting a part of the microwave circuit is formed therein. (2) The microwave IC package according to claim 1, wherein the passive circuit is a band rejection filter consisting of a sector-shaped λ/4 open stub. (3) The microwave IC package according to claim 1, wherein the passive circuit includes a trimming conductor.