JPH04276905A - Manufacture of strip line - Google Patents

Abstract

PURPOSE:To manufacture the strip line able to easily adjust a microwave circuit so that its high frequency characteristic is a desired characteristic without use of the wire bonding technology with respect to the manufacture of the strip line used for the microwave circuit such as a microwave transistor(TR) or a microwave integrated circuit. CONSTITUTION:A signal transmission conductor 12 through which a signal is sent and a strip conductor 16 comprising a characteristic adjustment conductor 14 branched from the signal transmission conductor 12 are formed on a dielectric board 10, and the characteristic adjustment conductor 14 is cut off so that the high frequency characteristic of the strip conductor 16 is a desired characteristic to separate at least part of the characteristic adjustment conductor 14 from the signal transmission conductor 12.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a strip line used in microwave circuits such as microwave transistors and microwave integrated circuits.

0002

[Prior Art] Small microwave circuits such as microwave transistors and microwave integrated circuits are used in military air and ship communication equipment, satellite equipment and ground station equipment for satellite communication, and various radar equipment. It was born out of the demand for improved performance, smaller size, lighter weight, and higher reliability.

[0003] Strip lines used as microwave transmission lines in microwave circuits have a planar structure consisting of a ground conductor and a strip conductor, so they are smaller than conventional three-dimensional circuits using waveguides. is possible, the circuit can be configured freely, and there is little signal transmission loss.
Broadband frequency characteristics can be obtained. In microwave circuits using strip lines, such as microwave transistor circuits, the physical size of each component is large relative to the wavelength of the microwave band, so the characteristics of the microwave circuit can vary greatly depending on how they are mounted. I end up. For this reason, it is necessary to adjust the characteristics of the microwave circuit during assembly.

FIG. 5 shows a conventional example of a microwave circuit that takes into consideration the adjustment of characteristics during assembly. Figure 5(a)
5 is a partially cutaway perspective view of the microwave circuit before characteristic adjustment, and FIG. 5(b) is a plan view of the microwave circuit after characteristic adjustment. A grounding metal substrate 20 is placed on the back side of the alumina dielectric substrate 22.
A strip conductor 24 and a characteristic adjustment conductor 26 made of gold (Au) are formed on the surface of the dielectric substrate 22. The strip line is composed of a grounding metal substrate 20 and a strip conductor 24. A plurality of characteristic adjustment conductors 26 are arranged near the strip conductor 24.

In order to make the high frequency characteristics of the microwave circuit desired, as shown in FIG. 5(b), a characteristic adjustment conductor 26 is connected to the strip conductor 24 with a bonding wire 28 to adjust the characteristics. . That is, the two characteristic adjustment conductors 2 on the left side are connected by the bonding wire 28.
6 are connected in series and connected to the strip conductor 24, and one characteristic adjustment conductor 26 on the right side is connected to the strip conductor 24 to adjust the high frequency characteristics of the microwave circuit.

[0006]

However, in the above-mentioned prior art, since the strip conductor 24 and the characteristic adjustment conductor 26 are connected by the bonding wire 28, the dielectric substrate 22 is made of a material such as alumina that can be reliably wire bonded. The problem was that it had to be used.

[0007] Furthermore, the length and number of bonding wires 28 themselves, the position of bonding, etc. also affect the characteristics.
There was a problem in that a wire bonding technique with good reproducibility was required. Furthermore, since the characteristics of the combination of the characteristic adjustment conductor 26 and the bonding wire 28 are unknown, there is a problem in that it is necessary to perform the characteristic adjustment work by trial and error.

[0008] An object of the present invention is to provide a method for manufacturing a strip line that allows a microwave circuit to be easily adjusted so that the high frequency characteristics become desired characteristics without using wire bonding technology.

[0009]

[Means for Solving the Problems] The above object is to provide a method for manufacturing a strip line composed of strip conductors, in which a signal transmission conductor through which a signal is transmitted and a signal transmission conductor branched from the signal transmission conductor are disposed on a dielectric substrate. A strip conductor is formed of a characteristic adjusting conductor, the characteristic adjusting conductor is cut so that the high frequency characteristics of the strip conductor become a desired characteristic, and at least a part of the characteristic adjusting conductor is connected to the signal. This is achieved by a method for manufacturing a strip line, which is characterized in that it is separated from a transmission conductor.

0010

[Operation] According to the present invention, the characteristics are adjusted by cutting the characteristic adjusting conductor and separating at least a part of the characteristic adjusting conductor from the signal transmission conductor, so wire bonding technology can be used. Therefore, the characteristics of the microwave circuit can be easily adjusted.

[0011]

Embodiment A method for manufacturing a strip line according to a first embodiment of the present invention will be explained with reference to FIG. FIG. 1(a) is a plan view of the microwave circuit before characteristic adjustment, and FIG. 1(b) is a plan view of the microwave circuit after characteristic adjustment. In this embodiment, on the dielectric substrate 10 of Teflon (trademark of du Pont Co., material name: polytetrafluoroethylene) substrate,
A strip conductor 16 is formed of a signal transmission conductor 12 through which a signal is transmitted and a characteristic adjustment conductor 14 branched from the signal transmission conductor 12. strip conductor 16
is made of gold-plated copper. The characteristic adjustment conductor 14 has a plurality of lands 1 as shown in FIG. 1(a).
4a and a thin connecting portion 14b connecting each land 14a. Three rows of three lands 14a are provided from the signal transmission conductor 12 via thin connection portions 14b.

The high frequency characteristics when the thin connection portion 14b is cut are predicted by numerical simulation using a computer, the cutting point is determined so that the high frequency characteristics become the desired characteristics, and the characteristic adjustment conductor 14 is used for signal transmission. Adjustment is made by disconnecting from the conductor 12. The land 14a is separated from the signal transmission conductor 12 by cutting the pattern of the thin connection portion 14b with a cutter or the like. For example, Figure 1(b)
As shown in FIG.
By cutting 4b, the left column has two lands 1
4a are connected, the land 14a in the center row is not connected, and the one land 14a in the right row is connected.

According to this embodiment, the characteristic adjustment conductor is composed of a plurality of lands, and the characteristics are adjusted by cutting the connecting portion and separating the lands from the signal transmission conductor, so that the characteristics after adjustment are can be predicted and adjusted in a short time with a little bit of cut and try. Also,
In this example, the dielectric substrate is a substrate made of an organic polymer material such as a soft Teflon substrate, and the connection part to be cut is made thin, so it can be easily cut with a cutter etc. without using a wire bonding device as in the past. Characteristic adjustment work is possible.

Furthermore, even when the dielectric substrate is made of a material that is difficult to perform reliable wire bonding with, such as a Teflon substrate, the characteristics can be easily adjusted. FIG. 2 shows a method for manufacturing a strip line according to a second embodiment of the present invention.
Explain using. FIG. 2(a) is a plan view of the microwave circuit before characteristic adjustment, and FIG. 2(b) is a plan view of the microwave circuit after characteristic adjustment. Components that are the same as those in the first embodiment shown in FIG. 1 are given the same reference numerals, and explanations thereof are omitted.

In this embodiment, as shown in FIG. 2(a),
As the characteristic adjustment conductor 14, an open end stub 14c branched from the signal transmission conductor 12 is used. In this embodiment, three open end stubs 14c are branched from the signal transmission conductor 12. To adjust the characteristics, the open-end stub 14c is cut at a position predicted by numerical simulation so that the high-frequency characteristics become the desired characteristics, and a part of the open-end stub 14c is separated from the signal transmission conductor 12. . For example, as shown in FIG. 2(b), three open end stubs 14
About 2/3 of the left open end stub 14c and about 1/3 of the right open end stub 14c are connected to the signal transmission conductor 14a.

According to this embodiment, since the conductor for adjusting characteristics is constituted by an open-end stub, the conductor for adjusting characteristics can be cut at any position, increasing the degree of freedom in adjusting characteristics. A method for manufacturing a strip line according to a third embodiment of the present invention will be described with reference to FIGS. 3 and 4. Figure 3(a)
is a plan view of the microwave amplifier, and FIG. 3(b) is a cross-sectional view taken along line A-A of the same microwave amplifier. FIG. 4 is an explanatory diagram of the characteristic adjustment state of the same microwave amplifier.

Microwave amplifier (8G
Hz power amplifier) is provided with an input circuit 40 on the input side (gate terminal 30g side) of the FET element 30 that amplifies microwaves, and an output circuit 50 on the output side (drain terminal 30d side). FET element 30 is case metal 3
2, and both the input circuit 40 and the output circuit 50 are fixed to the case metal 32.

The input circuit 40 and the output circuit 50 are constituted by microwave circuits formed by etching and patterning the copper layer on one side of a Teflon glass laminate having copper layers formed on both sides. In this embodiment, the input circuit 40
The details of the output circuit 50 will be explained, and the illustration and explanation of the details of the output circuit 50 will be omitted. The Teflon glass laminate 41 on which the input circuit 40 is formed has a dielectric constant ε of 10, a thickness of 0.635 mm, and a rectangular shape measuring 5 mm in length and 8 mm in width. The lower surface of this Teflon glass laminate plate 41 has 1
A 7.5 μm thick copper layer 42 is formed and fixed to the case metal 32 with solder 34. A copper layer 43 with a thickness of 17.5 μm is patterned on the upper surface of the Teflon glass laminate 41, and a strip is formed of a signal transmission conductor 44 through which signals are transmitted and a characteristic adjustment conductor 45 branched from the signal transmission conductor 44. A conductor 46 is formed. Note that the surfaces of the copper layers 42 and 43 are plated with gold having a thickness of 3 to 5 μm.

The signal transmission conductor 44 has a width W1 of 0.6 mm.
It has a band shape. The microwave input from the left end is transmitted through the signal transmission conductor 44 and input to the gate terminal 30g of the FET element 30. The characteristic adjustment conductor 45 is composed of a plurality of lands 45a and a thin connection portion 45b that connects each land 45a. Three rows of two lands 45a are provided on both sides of the signal transmission conductor 44 via thin connecting portions 45b. Connection portions 45b branch from the signal transmission conductor 44 every length d1 (=0.8 mm) from the connection point B between the signal transmission conductor 44 and the gate terminal 30g, and are connected to two lands 45a each. .

The land 45a has a square pattern with a width W2 of 0.6 mm and a length d2 of 0.6 mm.
b is a rectangular pattern with a width W3 of 0.1 mm and a length d3 of 0.2 mm. To adjust the characteristics, use the thin connection part 45b.
is removed from the signal transmission conductor 44 by the needle tip and the land 4 is removed from the signal transmission conductor 44.
This is done by cutting off 5a. Next, a specific example of a method for manufacturing a strip line with adjusted characteristics according to this embodiment will be described using FIG. 4.

If Zl is the impedance viewed from the connection point B between the signal transmission conductor 44 and the gate terminal 30g of the FET element 30 toward the FET element 30 side, and Zs is the impedance viewed toward the input circuit 40 side, then the impedance Zl and the impedance Zs are Power is most efficiently input to the FET element 30 when there is a complex conjugate relationship. Impedance Z
l changes depending on the voltage and current applied to the FET element 30, but is basically a value specific to the FET element 30. Impedance Zs is adjusted using the characteristic adjustment conductor 45 so that it has a complex conjugate relationship with this impedance Zl.

The basis for adjusting the impedance Zs using the characteristic adjusting conductor 45 is to change the value of the imaginary part of the impedance Zs mainly by changing how far the land 45a is separated from the connection point B, and mainly by changing the value of the imaginary part of the impedance Zs by changing how many lands 45a are connected. Change the value of the real part of Zs. FIG. 4(a) shows the connection of the strip conductor 46 by the signal transmission conductor 44 and the characteristic adjustment conductor 45 when only the land P branched from a point d1 away from the connection point B is connected and the other lands are disconnected. It shows the condition. Calculating the impedance Zs in this case, Zs=34
．． 4-j9.5 [Ω].

FIG. 4(b) shows the signal transmission conductor 44 and the characteristic adjustment conductor 4 when land Q is further connected to land P.
5 shows the connection state of the strip conductor 46 according to No. 5. Calculating the impedance Zs in this case, Z
s=20.5-j9.0[Ω], and compared to the case of FIG. 4(a), the imaginary part hardly changes and only the real part changes (decreases).

FIG. 4(c) shows the signal transmission conductor 44 and the characteristic adjustment conductor 4 when a land R branched from a point d1, which is twice the distance from the connection point B, is connected instead of the land P.
5 shows the connection state of the strip conductor 46 according to No. 5. Calculating the impedance Zs in this case, Z
s=32.3+j0.4 [Ω], and compared to the case of FIG. 4(a), the real part hardly changes and only the imaginary part changes (increases).

According to this embodiment, it is possible to adjust the characteristics while predicting the impedance value depending on which land of the characteristic adjustment conductor is left. The present invention is not limited to the above embodiments, and various modifications are possible. For example, in the above embodiments, the shape of the characteristic adjustment conductor was a land or an open-end stub, but any shape can be used as long as it is possible to branch out from the signal transmission conductor and cut a part of it. good.

Further, in the above embodiment, the dielectric substrate is made of a Teflon substrate, but the dielectric substrate may be made of other materials, such as glass epoxy resin.

[0027]

As described above, according to the present invention, a microwave circuit can be easily adjusted to have desired high frequency characteristics without using wire bonding technology.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a method for manufacturing a strip line according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a method for manufacturing a strip line according to a second embodiment of the present invention.

FIG. 3 is an explanatory diagram of a method for manufacturing a strip line according to a third embodiment of the present invention.

FIG. 4 is an explanatory diagram of a method for manufacturing a strip line according to a third embodiment of the present invention.

FIG. 5 is a diagram showing a conventional example of a microwave circuit.

[Explanation of symbols]

10...Dielectric substrate 12...Signal transmission conductor 14...Conductor for characteristic adjustment 14a...Land 14b...Connection part 14c...Open end stub 16...Strip conductor 20...Grounding metal board 22...Dielectric substrate 24...Strip conductor 26...Conductor for characteristic adjustment 28...Bonding wire 30...FET element 30g...gate terminal 30d...Drain terminal 32...Case metal 34...Solder 40...Input circuit 41...Teflon glass laminate board 42...Copper layer 43...Copper layer 44...Signal transmission conductor 45...Conductor for characteristic adjustment 45a...land 45b...Connection part 46...Strip conductor 50...Output circuit

Claims (1)

[Claims] 1. A method for manufacturing a strip line composed of strip conductors, comprising a signal transmission conductor through which a signal is transmitted and a characteristic adjustment conductor branched from the signal transmission conductor on a dielectric substrate. forming a strip conductor, and cutting the characteristic adjusting conductor so that the high frequency characteristics of the strip conductor become desired characteristics, separating at least a part of the characteristic adjusting conductor from the signal transmission conductor. Features: Strip line manufacturing method.