JP3127645B2 - Package 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 so-called MIC in which a microwave / millimeter wave IC circuit of a dielectric substrate is mounted.
The structure of the package or the housing. M
In an IC package or housing, unnecessary resonance modes of electromagnetic waves are generated due to the mechanical space inside and the structure of the dielectric part, and unnecessary cracks are generated in the frequency characteristics of microwave and millimeter wave circuits. This may lead to deterioration of characteristics such as intrusion. In particular, in the MIC package, there is no easy and effective method for suppressing the generation of the unnecessary resonance mode, and there is a restriction that the MIC cannot be used near the resonance frequency. There is a need for simple and effective countermeasures that eliminate restrictions.

[0002]

2. Description of the Related Art Conventionally, as a countermeasure, in an MIC package, for example, an appropriate dielectric piece is additionally mounted on a dielectric circuit board to change an electromagnetic field distribution inside the package. The unnecessary resonance frequency described above is set out of a frequency range where there is no influence. Further, in the case, the generation of unnecessary electric resonance inside the case was suppressed by attaching a radio wave absorber to the back surface of the lid. FIG. 3 shows an example of a conventional measure. In the figure, 3 is an alumina ceramic substrate constituting the MIC, 4 is a package body made of a conductor, 5 is a conventional lid made of a conductor,
6 is a dielectric piece to be added.

[0003]

SUMMARY OF THE INVENTION In the above conventional measures,
In the method of mounting additional dielectric pieces inside the MIC package, it is often difficult to secure sufficient space for adding the dielectric pieces, and the MIC package is soldered by soldering. There is a problem that it is generally difficult to mount a radio wave absorber inside the hermetic seal because the hermetic seal is often performed. An object of the present invention is to provide an MIC package structure in which a countermeasure object can be easily mounted inside the package and unnecessary resonance frequencies can be easily removed from the other.

[0004]

FIG. 1 is a principle diagram showing a basic structure of a lid of a package of a high-frequency circuit such as a microwave or a millimeter wave according to the present invention for achieving this object. In the figure, reference numeral 1 denotes a lid of the present invention, 12 denotes a dielectric forming the main body of the lid 1, and 11 denotes a conductor film formed on the surface of the dielectric 12. And a circuit in which a high-frequency circuit is formed on a dielectric substrate
In the package structure in which the substrate is mounted inside, the first surface which is the surface of the lid 1 is uniformly covered with the conductive film 11, and the second surface which is the back surface of the first surface of the lid 1 is one side. Part is exposed
The lid made of a dielectric plate is usually
The first surface faces the high-frequency circuit forming surface on the circuit board.
And place it. And unnecessary resonance is caused by the above arrangement.
If so, place the second surface of lid 1 on the circuit board.
It is arranged facing the frequency circuit forming surface.

[0005]

According to the present invention, when unnecessary resonance occurs , the second surface of the lid 1 in which a part of the internal dielectric 12 is exposed is removed.
Facing the high-frequency circuit formation surface on the circuit board inside the package
The first surface, which is the surface of the lid 1 on which the conductive film 11 is normally formed, is normally placed on the circuit board.
The volume ratio of the dielectric portion to the empty space inside the package is increased compared to the case where the package is opposed to the high-frequency circuit forming surface, and the effect of shortening the effective wavelength by the so-called dielectric increases, and The resonance frequency of the so-called TE ₁₀₁ mode, which is the lowest resonance mode, is out of the region where the resonance frequency is low.

[0006]

FIG. 2 shows a package structure of a microwave / millimeter wave circuit according to an embodiment of the present invention. In the figure, 11 is a conductor film formed by gold plating, 12 is a dielectric material of alumina ceramic, and both of 11 and 12 constitute the lid 1. Reference numeral 3 denotes an alumina ceramic circuit board constituting the MIC, which is a microwave / millimeter-wave IC circuit, and reference numeral 4 denotes a package body made of a conductor. In FIG. 2A, the mounting state 1 is a normal case in which an unnecessary resonance mode does not occur inside the package, and the surface on which the conductive film 11 of the lid 1 is uniformly plated is
A diagram is shown in which the package body 4 made of a conductor is adhered to the package body 4 made of a conductor by, for example, soldering with gold tin and hermetically sealed inside the package. In the mounting state 2 of FIG. 2B, the back surface of the lid 1 where a part of the alumina ceramic 12 of the same lid 1 is exposed is placed inside the package, and the package body 4 and gold tin are similarly soldered. The figure which bonded and was airtightly sealed is shown.

[0007]

As described above, according to the present invention, unnecessary resonance frequencies inside a package are reduced to a low frequency region by using a cover in which a dielectric of a main body is exposed on a part of a back surface. Is possible, the MIC can be used in a frequency band that cannot be used due to package resonance that has occurred in the case of a conventional lid with only a conductor, and the effect of eliminating restrictions on the use of the MIC is obtained. Can be

[Brief description of the drawings]

FIG. 1 is a principle diagram showing a basic configuration of a package structure of a microwave / millimeter wave circuit of the present invention.

FIG. 2 is a diagram showing a package structure of a microwave / millimeter wave circuit according to an embodiment of the present invention.

FIG. 3 is a diagram showing a package structure of a conventional microwave / millimeter wave circuit.

[Explanation of symbols]

1 is a lid of the present invention, 12 is a dielectric material forming the body of the lid 1, 11
Is a conductor film formed on the surface of the dielectric material 12, 3 is a dielectric substrate of a microwave / millimeter wave circuit inside the package, and 4 is a package body made of a conductor.

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) H01L 23/02 H01L 23/12 H05K 9/00

Claims (1)

(57) [Claims] 1. A circuit in which a high-frequency circuit is formed on a dielectric substrate.
In a package structure in which a circuit board is mounted inside, a first surface is uniformly covered with a conductive film, and a back surface of the first surface.
The second surface is a partially exposed dielectric plate.
Cover, usually, the first surface of the cover to the circuit board
Place it facing the high frequency circuit forming surface
Therefore, when unnecessary resonance occurs, the second
Face to the high-frequency circuit forming surface on the circuit board
A package structure characterized by being arranged .