JPS60149153A - Microwave circuit - Google Patents

Abstract

PURPOSE:To equivalently reduce the lead wire length of the titled circuit by a method wherein the conduction part of a semiconductor package is made of common ground conductor by direct connection of the package to a dielectric substrate. CONSTITUTION:The conventional ground conductor is omitted by connecting conductive packages 1-1-1-3 containing semiconductor chips and input-output matching circuits directly to the dielectric substrate (lD thick), resulting in the reduction in the lengths of terminals 2-1-2-4 of the packages 1-1-1-3; then, adjacent package terminals 2-1-2-4 are connected by means of micro strip lines 3-1 and 3-2 (line length lS). At this time, the total length of connection lines of semiconductor components is reduced to 2lD+lS, and structural discontinuous points are reduced two points between packages 1-1-1-3 and the lines 3-1 and 3-2. Further, making the packages 1-1-1-3 of Au-plated kovar and the substrate of alumina ceramic makes the coefficient of linear expansion of each part approximately equal and appropriate. This construction realizes the reduction in member of discontinuous points of the circuit structure and the reduction in line length, resulting in the improvement in performance of this circuit.

Description

Detailed Description of the Invention (Industrial Field of Application) The present invention is an improvement of a microwave circuit formed by interconnecting microwave semiconductor components using a microwave semiconductor component configured by housing a semiconductor chip in a conductive pancage. Regarding.

(Prior art) In recent years, microwave integrated circuits (MI
C) As technology advances and QaAs field effect transistors that can be used in a wide frequency range from the microwave band to the millimeter wave band are put into practical use, the performance of microwave circuits has significantly improved. It has become smaller. However, in conventional transistors and diodes, which consist of a single semiconductor device chip housed in a pancase and equipped with external connection terminals, the capacitance of the package itself, the inductance of the connection terminals themselves, etc. , which hindered the broadband characteristics of circuits using these semiconductor components. For this reason, there is a need for a wide-band, high-gain, low-noise-figure transistor in which multiple semiconductor chips and input/output matching circuits are housed inside the same conductive pancage, and such transistors are being actively developed. Ta.

For example, in a 14 GHz band transistor that uses two QaAs field effect transistor chips and houses an input/output matching circuit and a matching circuit between two GaAs field effect transistors in the same package, Dimensions are 9X20X4wn, frequency band is 14~15GHz,
Noise figure is 3dB.

The gain was 16 dB. However, in many microwave circuits of this type, although packages for conductive semiconductor components are used, the grounding conductor of the grounding strip line is connected to the common ground attached to the conductive package. Since it is formed separately from the conductor, there is a problem in that the influence of parasitic elements such as capacitance and inductance cannot be ignored.

For example, FIG. 1 is a cross-sectional view showing a typical example of the above microwave circuit constructed according to the prior art. In FIG. 1, 1-1 to 1-3 are semiconductor components 2-1 to 2-4, each of which is constructed by housing a semiconductor chip and an input/output matching circuit in a conductive pancake, and 2-4 is a semiconductor component 1-3, respectively.
Terminals 1 to 1-3, 6-1 and 6-2 are microstrip lines for connecting semiconductor components 1-1 to 1-3, and 4-1 and 4-2 are dielectric substrates, respectively. ,
5 is a common ground conductor for semiconductor components 1-1 to 1-3 and microstrip lines 5-1 and 3-2. In Figure 1, semiconductor components 1-1 to 1-3 are micros)
Although they are connected by J-tube lines 3-1, 3-2, they can also be connected by an inlator, a resistive attenuator, a directional coupler, or other circuit elements. As can be readily understood from FIG. 1, there are discontinuities in the circuit at each connection between the semiconductor components 1-1 to 1-3 and the microstrip line 3-1, 5-2 as follows. .

That is, between the semiconductor components 1-1 to 1-3 and the ground conductor 5, between the ground conductor 5 and the dielectric nine-piece substrate 4-1, 4-2,
In addition, there are discontinuous points between the dielectric substrates 4-1 and 4-2 and the microstrip lines 1 and 3-2. In addition, the ground conductor 5 and the dielectric substrate 4-1.4-2
Assuming that the thickness of the semiconductor component 1 is tG and tD, and the length of the strip line is 'gltB,
-The total length of the line for connecting between 1 and 1-3 tc
is 1(3=2 (tG+tD)+ts@·-txt The line is the shortest, and the fewer the number of discontinuous points, the better.

When the wavelength is short, such as in a microwave circuit, it is particularly important that the number of discontinuous points is small. Furthermore, terminal 2
One end of -1 to 2-4 is sealed in glass to the package of semiconductor components 1-1 to 1-3, and the other end is IJ tube line 3.
-1.3-2 are usually soldered or wire bonded, and stress due to expansion or contraction caused by changes in environmental temperature is applied to both ends of the terminals 2-1 to 2-4. Therefore, a circuit configuration with sufficient margin for such stress is required.

Therefore, the lengths of the terminals 2-1 to 2-4 are shortened to reduce the absolute amount of expansion and contraction, and the terminals 2-1 to 2-2 are
It is necessary to construct the ground conductor 5, as well as the dielectric substrate 4-1, 4-2, from a material with a coefficient of expansion equal to the coefficient of expansion -4.

(Objective of the Invention) The object of the present invention is to omit the ground conductor existing between the package of the semiconductor component and the dielectric substrate, and directly connect the two.
The object of the present invention is to provide a microwave circuit constructed in such a way that the above-mentioned drawbacks can be eliminated by using the conductive portion of a semiconductor component package as a common grounding conductor, and the length of the lead line can be shortened isometrically. .

(Structure of the Invention) A microwave circuit according to the present invention includes a plurality of semiconductor components, one or more dielectric substrates, and one or more microstrip lines.

The plurality of semiconductor components consist of electrically conductive packages with one or more terminals, each for housing one or more microwave device chips and providing active functionality.

The dielectric substrate or substrates are positioned to maintain electrical conductivity between the conductive pancages of the plurality of semiconductor components.

(Single or plural micros) The IJ tube wire is provided on one or more dielectric substrates and is for connecting between one or more terminals, respectively.

(Example) Next, the present invention will be described in detail with reference to drawing 'f'.

FIG. 2 is a sectional view showing an embodiment of the microwave circuit according to the present invention. In Figure 2, 1-1 to 1-3.2
-1 to 2-4, 3-1, and 6-214-1.4-2 are numbers indicating the same elements as shown in FIG. 1, respectively. FIG. 2 differs from FIG. 1 in that a semiconductor shoe cage is used as a ground conductor for the connecting microstrip line 1.6-2. As a result of using the semiconductor pancase itself as a grounding conductor for the connecting microstrip lines 3-1 and 6=2, the grounding conductor 5 shown in FIG. The discontinuity points in the connection between the microstrip lines &-1 and 6-2 are reduced to two, and the total length td of the connection line between the semiconductor components is ld=21. This is shortened to D+ t B (2). Furthermore, stress such as expansion and contraction due to temperature of the terminals 2-1 to 2-4 is also reduced.

Generally, the packages of the semiconductor components 1-1 to 1-3 are made of Kovar material plated with gold, so they have the best corrosion resistance and solderability. Therefore,
Furthermore, when alumina ceramic is used as the dielectric substrates 4-1 and 4-2, the net expansion coefficients of each part are approximately equal, making it ideal as a ground conductor. Even when materials such as Kovar material or alumina ceramic are not used, the reduction of discontinuities in the circuit structure and the shortening of line length greatly contribute to improving the performance of microwave circuits.

In the above description, a simple microstrip line was used as the connection circuit, but it goes without saying that isolators, directional couplers, power dividers, and other microwave circuits can be used.

(Effects of the Invention) As explained above, in the present invention, the ground conductor existing between the semiconductor component package and the dielectric substrate is omitted and the two are directly connected, and the conductive portion of the semiconductor component package is commonly used. By using it as a ground conductor, it is possible to shorten the lead line length isometrically, which has the effect of significantly reducing the influence of parasitic elements in the microwave band.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing an example of a microwave circuit according to the prior art. FIG. 2 is a sectional view showing an embodiment of the microwave circuit according to the present invention. 1-171-3...Semiconductor components 2-1 to 2-4..., terminals 3-1.3-2--Microstrip line for connection 4-1.4-2...φ dielectric Board 5... Ground conductor

Claims (1)

[Claims] between a plurality of semiconductor components, each consisting of a conductive pancage with one or more terminals for accommodating one or more microwave device chips and providing active functionality; and a conductive package of the plurality of semiconductor components; one or more dielectric substrates for positioning so as to maintain conductivity; and one or more dielectric substrates for connecting between the one or more terminals, respectively, on the one or more dielectric substrates. A microwave circuit comprising one or more microstrip lines.