JP2758887B2 - Microwave IC mounting structure - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a microwave IC mounting structure for mounting an IC package accommodating a microwave IC (microwave integrated circuit) in a housing, and in particular, is drawn out of an IC package mounting surface. The present invention relates to a microwave IC mounting structure for reducing leakage of a microwave signal from a signal pin to an external circuit.

[0002]

2. Description of the Related Art In a conventional microwave IC, a microwave IC board on which a microwave circuit is mounted is housed in a package housing of an IC package, and signal pins for inputting and outputting microwave signals are coaxial with the package housing. A hermetic seal is formed as the center conductor of the line, and the signal pins are drawn out from the mounting surface (many back surfaces) of the package housing. The microwave IC is usually mounted with the mounting surface mounted on a mounting surface of a housing (a housing housing mounting surface) for housing another circuit. In many cases, the housing is connected to the built-in circuit board from the mounting surface as a center conductor of a coaxial line that forms the signal pins in the housing case. The microwave circuit in the IC package and the circuit in the housing are connected to form one module. Here, the mounting surface of the IC package is flat, and there is a considerable distance from the position of the mounting screw for mounting this IC package to the housing to the position of the signal pin due to structural restrictions. It is difficult to make sufficient contact between the mounting surface of the IC package around the signal pins and the mounting surface of the housing, and microwave signals passing through the signal pins leak from the gap between the IC package and the housing, There is a problem that the characteristics of the whole module are deteriorated.

A technique for improving the microwave signal leakage is disclosed in Japanese Patent Application Laid-Open No. Sho 62-269344 (title of the invention: mounting structure of microwave integrated circuit). In the disclosed gazette, a groove is provided on the mounting surface of the housing further outside the outer conductor portion of the coaxial line, and a seal ring made of a high-frequency absorbing material slightly thicker than the depth of the groove is fitted. Then, the mounting surface of the IC package is pressed and supported on the mounting surface of the housing. As a result, even if there is a gap between the mounting surface and the mounting surface, the signal pin is completely surrounded by the mounting surface, the mounting surface, and the seal ring, and the signal pin is There is an effect that the microwave signal heading for is absorbed by the seal ring and does not leak outside.

[0004]

However, the technique disclosed in the above publication has a drawback that the IC package and the housing are easily contaminated because a high-frequency absorbing material that is easily damaged is used for the seal ring. Further, this technique has a drawback that unless the width of the seal ring is made large, microwave signals cannot be sufficiently absorbed, and it is difficult to increase the effect of preventing leakage of microwave signals.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned disadvantages of the prior art, to sufficiently prevent microwave signal leakage with a simple structure and to easily mount an IC package on a housing. The object of the present invention is to provide a mounting structure.

[0006]

SUMMARY OF THE INVENTION According to the present invention, there is provided a mounting structure of a microwave IC in which a microwave IC substrate is housed in a package housing and a center conductor of a first coaxial line formed in the package housing. An IC package for pulling out the signal pins from the mounting surface of the package housing, and mounting the IC package so that the mounting surface of the IC package faces the mounting surface of the housing housing, and the signal extracted from the mounting surface. And a housing for connecting a mounting pin to a built-in circuit board from a mounting surface of the housing housing as a center conductor of a second coaxial line formed on the housing housing. An outer conductor portion of the first coaxial line is cylindrically protruded from the mounting surface, and a chamfer is formed on the protruding tip portion. The housing includes a dished portion for receiving a chamfered tip of the protrusion on the outer conductor of the second coaxial line disposed on the mounting surface side. Prepare.

The mounting structure of the microwave IC may be configured such that the chamfering angle of the chamfering process and the dishing angle of the dishing portion are substantially the same with respect to the axis of the coaxial line.

[0008]

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

FIG. 1 is a structural view partially showing a cross-sectional view of an embodiment of a mounting structure of a microwave IC according to the present invention.
FIG. 2 is a detailed view of a portion A in the middle of mounting the IC package 1 on the housing 2 in the embodiment of FIG.
1 and 2, the IC package 1 is shown in a side view, and the housing 2 is shown in a sectional view. Also,
3A and 3B are structural views showing the IC package 1 used in the embodiment of FIG. 1, wherein FIG. 3A is a top view, FIG. 3B is a side view with a part cut away, and FIG. It is.

First, referring to FIG. 3, an IC package 1 mounts components constituting a microwave IC and mounts an IC substrate 11 forming a circuit pattern inside a package housing 10 which is a metal housing. Accommodating. The package housing 10 is provided with a plurality of bias pins 13 for supplying a power supply bias to the IC substrate 11 from the outside or for inputting / outputting a baseband signal, and for inputting and outputting a microwave signal. Signal pins 12a and 12b are provided. The bias pins 13 and the signal pins 12a and 12b are arranged on the rear side of the package case 11, and are mounted on the mounting surface 2 of the housing 2 (see FIG. 1).
It is pulled out perpendicular to the surface from the mounting surface 14 which is the surface to be mounted on 1. Also, the bias pins 13 and the signal pins 12a and 12b are provided in the package housing 10 in order to keep the inside of the package housing 10 including the IC substrate 11 airtight.
Hermetically sealed.

In the IC package 1 used in the present embodiment, the signal pins 12a and 12b are configured as a central conductor of a coaxial line connecting the IC board 11 and the housing 2. That is, when the signal pins 12a and 12b are hermetically sealed in the package housing 10,
The diameter of the signal pins 12a and 12b and the outer diameter of the sealing material 17 such as glass, that is, the inner diameter of the package housing 10 fused to the outer diameter are appropriately determined to form a coaxial line. The portion fused to the seal member 17 of the package housing 10 forms the outer conductor of the coaxial line. The outer conductor portion is shown as protrusions 15a and 15b, which protrude cylindrically from the mounting surface 14 and include chamfered portions 16a and 16b at the protruding tips, respectively. The operation and effect of the protrusions 15a and 15b and the chamfers 16a and 16b will be described later with reference to FIGS.

Next, referring to FIG. 1 and FIG.
The package 1 is attached to the housing 2. The housing 2 includes a metal housing housing 20 and circuit boards 30a and 30b housed in the housing housing 20 and mounting circuits other than the microwave IC. IC
The circuit of the package 1 and the circuit of the housing 2 constitute one module. The mounting surface 14 of the IC package 1 (package housing 10) is mounted to face the mounting surface 21 of the housing 2 (housing housing 20). I
The mounting of the C package 1 to the housing 2 is performed by mounting the mounting bracket 33 on the upper surface of the IC package 1 and then using mounting screws 34a, 34b, etc., which are arranged on four sides of the mounting bracket 33 off the end surface of the IC package 1. Is performed by fastening the mounting bracket 33 to the mounting surface 21 of the housing housing 20.

The mounting surface 21 of the housing 20 has
Holes are formed in the C package 10 at positions corresponding to the signal pins 12a and 12b, and the signal pins 12a and 12b
Are provided as outer conductor portions 22a and 22b of the coaxial line. When the IC package 1 is attached to the housing 2, the signal pins 12a and 12b
Are inserted into the pin receivers 31a and 31b disposed on the circuit boards 31a and 31b, respectively.
a and 31b are connected to circuit boards 31a and 31b connected to solders 32a and 32b, respectively.
The bias pins 13 of the IC package 1 are introduced into the housing 1 from the direction of the mounting surface 21 of the housing 20 and are connected to the circuit boards 31a and 31b by a predetermined method.

The outer conductor 2 of the housing 20
2a and 22b are IC packages 1 on the mounting surface 21 side.
Are provided with chamfered portions 23a and 23b which receive chamfered portions 16a and 16b (see FIG. 2) which are chamfered tips of the projections 15a and 15b, respectively. Chamfer angle θ1, of the chamfers 16a and 16b with respect to the axis of the coaxial line, ie, the signal pins 12a and 12b
The chamfer angle θ1 with respect to the axis of b
The angle is set to 45 degrees, which is almost the same angle as the dish angle θ2 with respect to and 23b. Therefore, IC package 1
Is attached to the housing 2 by screwing, the chamfered portions 16a and 16b of the IC package 1 are brought into close contact with the dished portions 23a and 23b of the housing 2 by receiving a strong force.

As described above, the mounting structure of the microwave IC according to the present embodiment includes the protrusions 15a and 15b, which are the outer conductors of the coaxial line of the IC package 1, and the outer conductors 22a and 22a of the coaxial line of the housing 2. 22b are in close contact with each other, so that even if the mounting surface 14 of the IC package 1 or the mounting surface 21 of the housing 2 is not a flat surface, the signals from the two coaxial lines having the signal pins 12a and 12b as the central conductors respectively. Leakage of microwave signals is prevented. When the IC package 1 is mounted on the housing 2 (see FIG. 2), the chamfered portions 16a and 16b of the package housing 10 are inserted into the housing 20 using the dished portions 23a and 23b of the housing 20 as a guide. Therefore, the positioning of the IC package 1 is easy, and the mounting structure of the microwave IC also has the effect of increasing the production efficiency during mounting.

[0016]

As described above, according to the present invention, the IC package mounted with the mounting surface mounted on the mounting surface of the housing is formed by moving the outer conductor of the coaxial line having the signal pin as the center conductor from the mounting surface. An outer conductor portion of a coaxial line having a cylindrical portion and a protruding tip portion having a chamfered end portion, wherein the housing is provided with the signal pin disposed on the mounting surface side as a center conductor. A protruding portion for receiving the chamfered tip of the projection, so that the projection and the housing are in close contact with each other at the time of mounting, and the mounting surface of the IC package and the housing Even if the mounting surface is not flat,
There is an effect that leakage of the microwave signal from the coaxial line is prevented.

[Brief description of the drawings]

FIG. 1 is a structural view partially showing a cross-sectional view of an embodiment of a mounting structure of a microwave IC according to the present invention.

FIG. 2 is a detailed view of a part A in an intermediate stage of mounting the IC package 1 on a housing 2 in the embodiment of FIG.

3A and 3B are structural views showing an IC package 1 used in the embodiment of FIG. 1, wherein FIG. 3A is a top view, FIG. 3B is a side view with a part cut away, and FIG. FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 IC package 10 Package housing 11 IC board 12a, 12b Signal pin 13 Bias pin 14 Mounting surface 15a, 15b Projection 16a, 16b Chamfer 17 Hermetic seal 2 Housing 20 Housing housing 21 Mounting surface 22a, 22b Outer conductor Parts 23a, 23b Dish processing parts 30a, 30b Circuit boards 31a, 31b Pin receivers 32a, 32b Solder 33 Mounting brackets 34a, 34b Mounting screws

Claims (2)

(57) [Claims] 1. A microwave IC substrate is accommodated in a package housing, and a signal pin, which is a central conductor of a first coaxial line formed on the package housing, is removed from a mounting surface of the package housing. And a second coaxial line for mounting the IC package with the mounting surface of the IC package facing the mounting surface of the housing housing and forming the signal pins drawn from the mounting surface on the housing housing. And a housing connected to a built-in circuit board from a mounting surface of the housing housing as a center conductor of the microwave IC. The IC package, wherein the IC package attaches an outer conductor of the first coaxial line to the mounting surface. And a protrusion which is formed into a cylindrical shape from the front and is chamfered at a protruding tip thereof, wherein the housing is mounted on the mounting surface. Mounting structure of a microwave IC, wherein a dish for receiving the chamfered distal end of the protrusion to the outer conductor of the second coaxial line are disposed also includes the unprocessed portion. 2. The microwave IC according to claim 1, wherein the chamfering angle of the chamfering and the dishing angle of the dishing portion have substantially the same angle with respect to the axis of the coaxial line. Mounting structure.