JPH09199910A - Strip line - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the strip line whose impedance remains the same even when its conductor width is selected identical to the width of pads matching various electronic components mounted on a board. SOLUTION: Strip lines 1A, 1B, 1C are formed such that at least two strip conductors 3A, 3B, 3C or over are arranged to one side of a board 2 and ground conductors 4A, 4B, 4C are arranged at positions corresponding to the strip conductors 3A, 3B, 3C with the board 2 inbetween. In this case, the board 2 is made up of at least two multi-layered wiring boards 2A, 2B, 2C, 2E, 2G, and each of two strip conductors 3A, 3B, 3C or over has a prescribed impedance with the ground conductors 4A, 4B, 4C arranged at a position of a desired thickness in the board 2, multi-layered wiring boards 2A, 2B, 2C, 2E, 2G respectively matching the width of the strip conductors 3A, 3B, 3C.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strip line, and more particularly to a strip line whose impedance is constant even if the width of the strip line is changed.

[0002]

2. Description of the Related Art A conductor width, a board thickness, a dielectric constant, etc. determine the impedance of a strip line.
Normally, in the case of a single plate substrate, the conductor width is made constant and a constant impedance is set.

[0003]

However, since there are various sizes of electronic parts mounted on the substrate, the size of the pad for mounting the electronic parts of different sizes is also different. As described above, when the conductor width of the strip line and the size (width) of the pad on which the electronic component is mounted are different, a state where impedance matching cannot be obtained occurs. If impedance matching cannot be achieved, reflection occurs at that portion and VSWR characteristics deteriorate.

The present invention solves the above-mentioned problems, and the same impedance is achieved even if the size (width) of the pad and the conductor width of the strip line that match the sizes of various electronic parts mounted on the substrate are the same. The purpose is to provide a stripline that

[0005]

The present invention has the following means to solve the above problems.

In the strip line according to claim 1 of the present invention, at least two strip conductors are arranged on one surface of the substrate, and a ground conductor is arranged at a position corresponding to the strip conductors with the substrate interposed therebetween. In the line, the board is at least two or more multi-layer wiring boards, and the two or more strip conductors are ground conductors arranged at desired thickness positions of the multi-layer wiring board according to the widths of the strip conductors. It is characterized in that it has a predetermined impedance between.

The strip line according to claim 2 of the present invention is characterized in that the impedance is constant and the width of each strip conductor is at least 2 or more.

According to the strip line of the present invention, since the substrate is a multi-layer wiring substrate, the width (width) of the pad matching the size of the electronic component mounted on the substrate should be the same. When the width of the strip conductor is widened, the impedance can be made constant by increasing the number of the multilayer wiring boards so as to increase the thickness of the board at the position where the ground conductor corresponding to the strip conductor is arranged. In this way, since the size (width) of the pad and the width of the strip conductor can be made the same, impedance matching between the pad and the strip conductor can be obtained.
That is, according to the strip line of the present invention, when the impedance is constant, the width of the strip conductor can be set to the number of the multilayer wiring boards. Therefore, the size of the pad can be changed by the number of the multilayer wiring boards.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to the drawings based on embodiments. FIG. 1 is a plan view of a dielectric substrate 2 on which strip lines 1A, 1B, 1C of the present invention are formed and a cross-sectional view taken along the line AA. The dielectric substrate 2 includes a plurality of dielectric substrates 2A, 2B, 2C, 2E.2.
It is a multi-layer wiring board made of G. In this embodiment, it is composed of seven dielectric substrates. The dielectric substrate 2 is composed of, for example, a wet multilayer thick film substrate made of alumina ceramic.

The strip lines 1A, 1B, 1C are strip conductors 3A, 3A formed on the surface of the dielectric substrate 2.
B, 3C and respective ground conductors 4A, 4B, 4C. A ground conductor 4A is provided for the strip conductor 3A, and a ground conductor 4B is provided for the strip conductor 3B.
However, for the strip conductor 3C, the ground conductor 4C
Correspondingly, strip lines 1A, 1B, and 1C are formed respectively. The ground conductor 4A corresponding to the strip conductor 3A is provided on the first dielectric substrate 2A.
The ground conductor 4B corresponding to the strip conductor 3B is provided on the second dielectric substrate 2B. Strip conductor 3
The thickness between B and the ground conductor 4B is thicker than the thickness between the strip conductor 3A and the ground conductor 4A.
The width of B is made wider than that of the strip conductor 3A so that the strip conductor 3A and the strip conductor 3B have the same impedance. The ground conductor 4C corresponding to the strip conductor 3C is provided on the fifth dielectric substrate 2E. Therefore, the width of the strip conductor 3C is equal to that of the strip conductor 3C.
The strip conductors 3A, 3B and the strip conductor 3C have the same impedance by making them wider than the width of B.

That is, in the present embodiment, the dielectric substrate 2 is composed of the dielectric substrates 2A, 2B, 2C, 2E, and 2G.
Since it is composed of a single multilayer wiring board, it can have seven kinds of strip conductor widths. In addition, the ground conductor 4 of each dielectric substrate 2A, 2B, 2C, 2E, 2G.
Although not shown, A, 4B, and 4E are electrically connected. In the figure, 5 is a pad provided at the end of the strip line 1A, 6 is a chip resistor mounted on the pad of the strip line 1B, and 7 is a chip capacitor mounted on the pad of the strip line 1C. In addition, strip lines 1A, 1B, 1C and ground conductors 4A, 4B, 4
E can be formed by a dry thick film technique, a plating technique, a technique of directly adhering a metal conductor, or the like when the dielectric substrate is composed of a wet multilayer thick film substrate made of alumina ceramics, for example.

[0012]

As described above, according to the strip line of the present invention, since the substrate is a multilayer wiring substrate,
When the width of the strip conductor is widened to have the same width (width) as the pad that matches the size of the electronic component to be mounted on the substrate, the position where the ground conductor corresponding to the strip conductor is arranged is the substrate. The impedance can be made constant by increasing the number of multilayer wiring boards so as to increase the thickness. In this way, since the size (width) of the pad and the width of the strip conductor can be made the same, impedance matching between the pad and the strip conductor can be obtained. That is, according to the strip line of the present invention, when the impedance is constant, the width of the strip conductor can be set to the number of the multilayer wiring boards. Therefore, the size of the pad can be changed by the number of the multilayer wiring boards.

[Brief description of drawings]

FIG. 1 is a plan view showing an example of an embodiment of a strip line of the present invention and a cross-sectional view taken along line AA thereof.

[Explanation of symbols]

1A, 1B, 1C Strip line 2 Dielectric substrate 2A, 2B, 2C, 2E, 2G Dielectric substrate 3A, 3B, 3C Strip conductor 4A, 4B, 4E Ground conductor 5 Pad 6 provided at the end of the strip line 6 Chip resistor mounted on the stripline pad 7 Chip capacitor mounted on the stripline pad

Claims (2)

[Claims] 1. A strip line in which at least two strip conductors are disposed on one surface of a substrate, and a ground conductor is disposed at a position corresponding to the strip conductor with the substrate sandwiched therebetween, the substrate has at least two or more strip conductors. In the multilayer wiring board, the two or more strip conductors have a predetermined impedance with a ground conductor arranged at a position of a desired thickness of the multilayer wiring board according to the width of each strip conductor. A stripline that is characterized. 2. The strip line according to claim 1, wherein the impedance is constant and the width of each strip conductor is at least two or more.