JPS634712B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an effective mounting structure for a removable high-frequency circuit unit housed in a housing constituting a high-frequency module.

High-frequency circuit components, which have traditionally been made up of waveguides, are now becoming microwave ICs (MICs).

Furthermore, various MICs are combined to provide high-frequency circuit functions and housed in a single housing. Furthermore, when a plurality of carriers carrying high frequency circuit units are mounted in the casing, it is necessary to interconnect the carriers.

The connection method is as shown in the cross-sectional view of Figure 1.
A high frequency circuit unit consisting of active elements such as MIC is mounted on carrier 2 and becomes a unit module that constitutes an independent circuit function.

A plurality of high frequency circuit units are housed in a housing 3 by screwing carriers 2 as shown in the figure. The signal conductor surfaces on the dielectric substrate 1 are connected using a connecting ribbon 4 by soldering, thermocompression bonding, or the like. Both ends thereof are connected to the high frequency connector 5 to form one high frequency module with one integrated circuit function.

The connection part is shown in Figure 2, A and B. Figure A is a top view showing the connection part, and Figure B is a sectional view showing the connection part.

Pattern conductor 1a of dielectric substrate 1 forming a signal line
A connecting ribbon 4 is placed on the connecting portion of the surface and fused and fixed by soldering or thermocompression bonding as described above.

However, the high frequency module obtained in this way has a grounding circuit formed between the bottom surface of the carrier 3 in contact with the casing 3 and the power supply substrate 1, as shown in FIG.
A circuit is formed by the distance L between the top surface and the top surface. Therefore, if the circuit is formed through an air layer and L is large, the high-frequency electromagnetic field will swarm, resulting in deterioration of the standing wave ratio (VSWR) of the connection and an increase in electromagnetic field radiation loss. Increased transmission loss caused operational instability due to external factors such as temperature and vibration, and this was particularly noticeable in the ultra-high frequency range, making it impossible to use. On the other hand, there is a demand for smaller size and lighter weight, and various studies are being conducted.

In view of the above points, the present invention provides an ultra-high frequency module in which a high frequency circuit unit composed of active elements can be attached and detached, and the discontinuity of the electromagnetic field is reduced at the connection part, and at the same time, an effective heat dissipation effect can be obtained. The purpose is to provide a modular structure that can be used.

The above purpose is to mount a high frequency circuit unit composed of active circuits mainly including microwave ICs on a carrier, fit the carrier into a predetermined recessed area formed in the housing, and then The high-frequency module is a high-frequency module in which a passive circuit formed on a dielectric substrate is connected to the high-frequency circuit unit, wherein a concave portion formed in the housing and a fitting portion of the carrier are fitted in a tapered shape. This is achieved by an ultra-high frequency module characterized in that a thin film sheet made of a soft metal with excellent thermal conductivity is provided on the bottom surface of a recess formed in the casing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 3 is a sectional view showing an ultra-high frequency module which is an embodiment of the present invention. FIG. 4 is a perspective view showing the mounting structure of the circuit unit in FIG. 3.

Passive circuits such as transmission lines, monitor circuits, couplers, and circulators are configured on the dielectric substrate directly mounted on the casing 13.

The carrier 12 includes a dielectric substrate 2 equipped with semiconductor elements, etc., including a high frequency circuit mainly including a MIC.
1 is mounted on the circuit board, and tests on circuit characteristics etc. are completed in advance before installation as a circuit unit. Furthermore, a soft metal foil 14 made of indium or the like is provided at the bottom of the casing to enhance the heat dissipation effect of the circuit unit. When this is installed, a gap is required at the bottom in order for the tapered part 15 of the carrier 12 to fully contact and lock the tapered part 17 of the recessed part 16 of the casing by screwing. A soft metal foil 14 for heat dissipation is provided in this gap as shown in the figure to fill the gap and lower the thermal resistance. For example, by laying indium foil, an increase in thermal resistance can be prevented.

FIG. 5 is an explanatory diagram showing a comparison of the connecting portion obtained by the present invention with a conventional example.

As explained in FIG. 2, the conventional grounding circuit is formed by reciprocating the distance B between the top surface of the dielectric substrate 1 and the bottom surface of the carrier.

In the present invention, a grounding circuit is formed by fitting the carrier 12 and the tapered parts 15, 17 of the housing 13, so the length of the grounding circuit is short-circuited in a reciprocating manner at the interval A shown in the figure, and the electromagnetic field is discontinuous. The thermal resistance between the carrier and the casing can be further reduced by using soft metal foil.
It is possible to obtain a module usable in the ultra-high frequency range for lowering through 4.

As explained above, by using the carrier structure of the present invention and increasing the heat dissipation effect by providing a soft metal, an ultra-high frequency module can be obtained, which is advantageous for downsizing the device and improving reliability.

According to the present invention, active circuit units that require individual adjustments and characteristic tests can be attached and detached, which improves work efficiency and facilitates replacement in the event of a failure, resulting in excellent effects. Its practical effects are remarkable.

[Brief explanation of the drawing]

Figure 1 is a sectional view showing a conventional high-frequency module structure, Figure 2 A and B show the connection part of the conventional example, A is a top view thereof, B is a sectional view, and Figure 3 is a cross-sectional view of the present invention. FIG. 4 is a perspective view showing the mounting structure of the circuit unit in FIG. 3, and FIG. 5 is an explanatory diagram illustrating the connection portion. In the figure, 1, 11, 21 are dielectric substrates,
2 and 12 are carriers, 3 and 13 are housings, 4 is a connection ribbon, 5 is a high-frequency connector, 14 is a soft metal foil, 15 is a tapered part of the carrier, 16 is a recess in the housing, and 17 is the housing The tapered portion of the recess is shown.

Claims (1)

[Claims] 1. A high-frequency circuit unit consisting of an active circuit mainly consisting of a microwave IC, etc. is mounted on a carrier, and the carrier is fitted into a predetermined recess area formed in a housing, and the dielectric substrate on the top surface of the housing is fitted. A high-frequency module that connects a passive circuit formed on the high-frequency circuit unit to the high-frequency circuit unit, the upper part of the fitting portion between the recess formed in the housing and the carrier having a tapered fitting structure. An ultra-high frequency module characterized in that a thin film sheet made of a soft metal with excellent thermal conductivity is provided on the bottom surface of the recess formed in the casing.