JPH0223035Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention is an improvement of a metal airtight container for enclosing a microwave integrated circuit consisting of a semiconductor chip, an impedance matching circuit board, and other electronic components. It is related to.

[Conventional technology]

FIG. 1 shows a cross-sectional structural diagram of a conventional metal airtight container for a microwave integrated circuit. The metal airtight container is composed of a base part 1, a lid part 2, and a terminal part 3,
A microwave integrated circuit 4 is mounted inside it.
When such a metal airtight container is intended to accommodate many circuit functions or is used in a high frequency band, the dimensions of the metal airtight container become close to the microwave wavelength, so the inner surface of the metal airtight container A resonance mode may occur due to microwave reflection at Therefore, frequency resonance or anti-resonance may occur in the transmission characteristics, or a steep frequency change may occur in the input and output impedances. Furthermore, when active elements are used, there are drawbacks such as unnecessary oscillations, which make it difficult to obtain desired characteristics and functions.

In addition, there is a technology that absorbs high frequencies by providing a package on a microwave circuit board and arranging a radio wave absorbing material on the inner surface of the package (Japanese Patent Application Laid-open No. 128901/1982), and a technology that absorbs high frequencies by placing a package on the microwave circuit board, and a technique that absorbs high frequencies by placing a package on the inside of the package. Technology to provide an electromagnetic absorber on the lower surface of the
157147) etc. have been proposed.

[Problems to be solved by the invention] However, these techniques merely aim to prevent microwaves from leaking to the outside; The circuit did not protect the integrated circuit from degrading its characteristics and functionality due to reflection of microwaves inside the container.

This invention eliminates the above-mentioned drawbacks, and prevents microwave leakage and prevents reflection of microwaves on the inner surface of the metal airtight container, thereby improving the characteristics of the microwave integrated circuit mounted inside the container. and to improve functionality.

[Means for solving problems]

The present invention is designed to prevent the reflection of microwaves on the inner surface of the metal hermetic container, which causes unnecessary resonance modes in the microwave integrated circuit, in a sealed metal container. It is characterized by a structure in which a radio wave absorber that attenuates microwaves is attached by a metallized layer formed on one side of the radio wave absorber.

[Effect]

A radio wave absorber attached to the inner surface of the metal airtight container absorbs the microwaves generated inside the metal airtight container, preventing the generation of resonance mode and anti-resonance mode caused by microwave reflection. Prevent sudden frequency changes in input and output impedance.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

FIG. 2 is a cross-sectional structural diagram for explaining the structure of the first embodiment of the present invention. The metal airtight container hermetically seals the microwave integrated circuit 4 with a base portion 1, a lid portion 2, and a terminal portion 3. A radio wave absorber 5 is brazed to the upper inner surface of the lid 2 of this airtight container. This brazing is performed by forming a metallized layer on one side of the radio wave absorber.

With this structure, electromagnetic waves directed toward the inner surface of the lid part 2 are absorbed and attenuated by the radio wave absorber 5, and no reflective resonance occurs.

FIG. 3 is a sectional view showing the structure of the second embodiment of the present invention. In this example, the terminal portion 3 does not penetrate through the base portion 1 but through the side wall, and the radio wave absorber 5 attached to the inner surface of the lid portion 2 and its function are similar to those of the first embodiment. The same is true.

Depending on the resonance mode, the radio wave absorber 5 can be brazed not only to the upper part of the inner surface but also to the side part of the inner surface.

The structure of the radio wave absorber 5 is shown in FIGS. 4 and 5. In FIG. 4, a metallized layer 6 is provided on one side of a sintered radio wave absorbing material 7. By brazing this metallized layer surface to the inner surface of the metal lid part 2, it can be firmly attached to the metal airtight container, and it is also advantageous because no gas is generated that would have a negative effect on the semiconductor of the microwave integrated circuit. It is.

In FIG. 5, the same metallized layer 6 as in FIG. 4 is provided on one side of a dielectric substrate 8, and a resistive film 9 is deposited on the opposite side. This metallized layer surface is brazed to the inner surface of the metal lid part 2 as described above. Further, the resistive film attenuates standing waves and resonant electromagnetic fields generated within the metal case when they pass through the resistive film, and provides the same effect as a radio wave absorbing material.

[Effect of idea]

As explained above, according to the structure of the present invention,
It is possible to prevent microwaves from being reflected on the inner surface of a metal airtight container that does not leak microwaves to the outside.
As a result, it is possible to prevent the generation of resonance modes, and there is an excellent effect that it is possible to stably obtain desired characteristics and functions.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of a metal airtight container for a microwave integrated circuit having a conventional structure. FIG. 2 is a sectional view of a metal airtight container for a microwave integrated circuit having a structure according to a first embodiment of the present invention. FIG. 3 is a sectional view of a metal airtight container for a microwave integrated circuit having a structure according to a second embodiment of the present invention. FIG. 4 is a sectional view showing the structure of the radio wave absorber. FIG. 5 is a sectional view showing the structure of the radio wave absorber. DESCRIPTION OF SYMBOLS 1...Metal airtight container base part, 2...Metal airtight container lid part, 3...Metal airtight container terminal part, 4
...Microwave integrated circuit, 5...Radio wave absorber, 6
...Metalized layer, 7...Radio wave absorbing material, 8...Dielectric substrate, 9...Resistive film.

Claims (1)

[Scope of Claim for Utility Model Registration] 1. In a metal airtight container that houses and seals a microwave integrated circuit including a semiconductor chip with a metal base part and a metal lid part, the inner surface of the metal lid part A radio wave absorber is attached by a metallized layer formed on one side of the radio wave absorber, and this radio wave absorber has a structure that attenuates the microwaves generated within the metal airtight container so that reflected resonance does not occur. A metal airtight container for a microwave integrated circuit, characterized by: 2.1 Radio wave absorber has a structure in which a metallized layer is formed on one side of a sintered radio wave absorber, and this metallized layer is brazed to the inner surface of a metal lid. A metal airtight container for microwave integrated circuits as described in item 1). 3 The radio wave absorber has a structure in which a metallized layer is formed on one side of a dielectric substrate, a resistive film is deposited on the other side, and the metallized layer is brazed to the inner surface of a metal lid.Registered as a utility model. A metal airtight container for a microwave integrated circuit according to claim (1).