JPH0117841Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a connection between a substrate on which a microwave circuit is formed and a casing.

When connecting a plurality of separate boards to provide one large function, the boards 1, 2, and 3 are arranged in order as shown in FIG. 1 and bonded by soldering or conductive adhesive. At this time, substrates 1 and 2,
As shown in FIG. 2, a slight gap is provided between 2 and 3 in consideration of thermal expansion. Therefore, if the amount of adhesive or solder required to bond the boards 1 to 3 and the housing 4 is not adjusted sufficiently, the board will become thin at high frequencies such as the X band (8 to 12.4 GHz) or higher. As a result, they often swell up from the gap between the substrates and short-circuit the upper conductors 1a and 2a. Moreover, when the amount is small, there is a drawback that the adhesive strength of the substrate is weak.

Conventionally, in such cases, a method was used in which a groove 4a was provided between the boards as shown in Figure 3, and excess solder or adhesive was allowed to escape there, but this method had the disadvantage that the electrical characteristics deteriorated in that part. It was hot.

When mounting a circulator as shown in FIG. 4, a hole 4b is provided in the housing 4 as shown in FIG. 5, a magnet Mg is inserted into this hole, and a ferrite substrate 5 is fixed around the hole 4b. However, if the size of the board is sufficiently large compared to the hole diameter, there is no problem, but if it is the same diameter or slightly larger, the adhesion to the casing tends to be incomplete, and high-frequency waves leaking from the board connection part may occur. The electromagnetic field often leaked into the holes, forming unnecessary resonant circuits and increasing line loss.

The purpose of the present invention is to eliminate such drawbacks, and the purpose is to provide a ferrite substrate that is installed over a hole into which a magnet is inserted and constitutes a circulator, and a plurality of substrates that are to be connected to the ferrite substrate. In a microwave circuit configured by fixing the ground planes of the ferrite substrate to a housing and connecting them to each other, the range extends to the entire ground plane of the ferrite substrate and the connecting portion of the ground planes of multiple substrates connected to the ferrite substrate. This is achieved by a microwave circuit formed by adhering a metal sheet to the housing and fixing it to the housing via the metal sheet.

The present invention will be explained below based on examples.

FIG. 6 shows an embodiment of the present invention, where a represents the surface;
b shows the back side.

In the figure, 6, 7, 8 are ceramic substrates, 9
4 is a gold sheet, and the same members as in FIG. 4 are given the same reference numerals.

The ceramic substrates 6, 7 are formed with circulator output strip lines 6a, 7a.
A dummy load 8a is formed on the ceramic substrate 8.

When fixing these to the case as shown,
b As shown in the figure, the gold sheet is placed on ceramic substrates 6, 7, 8.
It is bonded to the connecting portion of the ferrite substrate 5 by thermocompression bonding. As a result, even if it is fixed to the housing as shown in Figure 5,
There is no swelling of solder or adhesive, and no electromagnetic field leaks into the hole.

[Brief explanation of drawings]

Fig. 1 is a diagram showing a conventional structure, Fig. 2 is a diagram showing a connecting part of the board in Fig. 1, Fig. 3 is a diagram showing another conventional structure, Fig. 4 is a diagram showing a circulator, FIG. 5 is a diagram showing a fixing structure of the circulator, and FIG. 6 is a diagram showing an example of the present invention. In the figure, 5 is a ferrite substrate, 6, 7, and 8 are ceramic substrates, and 9 is a gold sheet.

Claims (1)

[Claims for Utility Model Registration] A ferrite substrate that is installed over a hole into which a magnet is inserted and constitutes a circulator, and a plurality of substrates to be connected to the ferrite substrate. The ground surfaces of the substrates are fixed to a housing and connected to each other. In a microwave circuit configured by: adhering a metal sheet to the entire ground plane of the ferrite substrate and the connecting portions of the ground planes of a plurality of substrates connected to the ferrite substrate; A microwave circuit fixed to the housing.