JP2006174262A - Board connection structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To connect microwave transmission lines installed at different heights while suppressing deterioration of standing wave ratio and generation of unnecessary radiation.
SOLUTION: A lower microwave transmission path 2, an upper microwave transmission path 3 having a height different from that of the lower microwave transmission path 2, a lower microwave transmission path 2, and an upper microwave transmission path 3 are provided. And a vertical microwave transmission path 4 coupled by integral molding. A part of the lower microwave transmission path 2 and a part of the upper microwave transmission path 3 extend from the vertical microwave transmission path 4.
[Selection] Figure 2

Description

  The present invention relates to a connection structure for substrates having microwave transmission paths installed at different heights.

  As a conventional substrate connection structure having a microwave transmission path, there is a system in which a plurality of substrates are connected by a coaxial line or the like using a connector, or a plurality of substrates are connected by a microwave transmission path constituted by a film or the like. .

  Patent Document 1 describes that strip patterns on a dielectric substrate are connected by through holes, and Patent Document 2 discloses that microstrip lines on a printed wiring board are connected by via holes, contact pads, and elastic connectors. In Patent Document 3, it is described that the signal line on the substrate is connected to the detour by a bump, and in Patent Document 4, the wiring substrate is connected by a metal bump. Patent Document 5 describes that signal patterns on a substrate are connected by solder bumps.

  FIG. 5 is a diagram for explaining a conventional substrate connection structure having microwave transmission paths installed at different heights. As shown in FIG. 5, a microwave transmission path 62 and an upper microwave transmission path 63 having an L-shaped structure are installed on an L-shaped conductor base 1 having a step portion 11 in the height direction. The upper substrate 64 of the transmission path 62 and the upper microwave transmission path 63 are connected by a connecting member 65.

  In the board connection structure shown in FIG. 5, a processing step for connecting the upper substrate 64 and the upper microwave transmission path 63 of the microwave transmission path 62 by the connection member 65 is required, and assembly when soldering the connection member 65 is performed. Due to variations in work finish, the mounting height of the connection member 65 changes, which causes deterioration of the standing wave ratio and generation of unnecessary radiation in the microwave space. In addition, as the number of parts increases, it is necessary to secure a space necessary for connection processing, and it is difficult to reduce the size. Furthermore, when connecting microwave transmission lines with different heights, especially when the height gap is large, the ground path 100 becomes long, causing deterioration of the standing wave ratio and generation of unnecessary radiation. It becomes. Further, a reflected wave is generated at a portion where the microwave transmission path is converted in the vertical or horizontal direction, which causes deterioration of the standing wave ratio.

JP-A-64-31494 (page 2, lower right column, line 7 to page 3, upper left column, line 6, FIG. 2) Japanese Patent Laid-Open No. 02-52496 (page 2, lower right column, line 7 to line 17, FIG. 1) Japanese Patent Laid-Open No. 11-88001 (Summary, Solution, FIG. 4) Japanese Patent Laid-Open No. 2002-271101 (paragraph 0025, FIG. 1) JP 2003-218482 A (summary, solving means, FIG. 1)

  Since the conventional substrate connection structure is configured as described above, a processing step for connecting a plurality of substrates having microwave transmission paths is required, and the standing wave ratio is reduced due to variations in the finish due to assembly work. There was a problem that it deteriorated or unnecessary radiation was generated in the microwave space. In addition, there is a problem that it is difficult to reduce the size because the number of parts increases and a space necessary for connection processing needs to be secured. In addition, when connecting microwave transmission lines with different heights, especially when the height gap is large, the ground path becomes longer, which deteriorates the standing wave ratio and generates unnecessary radiation. There was a problem. Furthermore, there is a problem that a reflected wave is generated at a portion where the microwave transmission path is converted in the vertical or horizontal direction, which causes a deterioration of the standing wave ratio.

  The present invention has been made to solve the above-described problems, and suppresses deterioration of the standing wave ratio and generation of unnecessary radiation when connecting microwave transmission lines installed at different heights. Another object of the present invention is to provide a substrate connection structure that can be reduced in the number of components and can be reduced in size, and that can reduce processing steps.

  It is another object of the present invention to provide a substrate connection structure that can suppress deterioration of the standing wave ratio in the horizontal-vertical conversion unit and the vertical-horizontal conversion unit of the microwave transmission path.

  Furthermore, by incorporating a microwave circuit in a structure for transmitting microwaves vertically, a substrate connection structure capable of connecting microwave transmission paths with different heights and having additional functions can be obtained. Objective.

  The substrate connection structure according to the present invention includes a lower microwave transmission path, an upper microwave transmission path having a height different from that of the lower microwave transmission path, the lower microwave transmission path, and the upper microwave transmission path. A vertical microwave transmission line coupled to the microwave transmission line by integral molding, and a part of the lower microwave transmission line and a part of the upper microwave transmission line extend from the vertical microwave transmission line. It is what.

  According to the present invention, it is possible to suppress the deterioration of the standing wave ratio and the generation of unnecessary radiation, to reduce the number of parts, to achieve a compact configuration, and to reduce the processing steps.

Embodiment 1 FIG.
FIG. 1 shows a microwave circuit according to Embodiment 1 of the present invention, and is a diagram for explaining a substrate connection structure. In this substrate connection structure, as shown in FIG. 1, a lower microwave transmission path 2 and an upper microwave transmission path 3 installed at different heights, and a lower microwave transmission path 2 and an upper microwave transmission path are installed. The lower microwave transmission path 2 is provided on the lower base surface 12 on the L-shaped conductor base 1 having a vertical microwave transmission path 4 connecting the wave transmission path 3 and having a step portion 11 in the height direction. A part of the upper microwave transmission path 3 is installed on the upper base surface 13 on the conductor base 1.

  FIG. 2 is a diagram showing a substrate connection structure according to Embodiment 1 of the present invention, in which the L-shaped conductor base 1 is deleted from FIG. As described above, the lower microwave transmission path 2 and the upper microwave transmission path 3 are provided on at least two planes having different heights, and the vertical microwave path between the lower microwave transmission path 2 and the upper microwave transmission path 3 is provided. The wave transmission path 4 is coupled.

  In FIG. 2, in the lower microwave transmission path 2, a microstrip line 21 is formed on the front surface, a ground pattern 22 is formed on the back surface, and a through hole 23 that connects the front surface and the back surface is formed. In the upper microwave transmission path 3, a microstrip line 31 is formed on the front surface, and a ground pattern 32 is formed on the back surface. Further, a coplanar line 41 and a ground pattern 42 are formed on the surface of the vertical microwave transmission path 4. The microstrip line 21 of the lower microwave transmission path 2 and the microstrip line 31 of the upper microwave transmission path 3 are connected via the coplanar line 41 of the vertical microwave transmission path 4, and the lower microwave transmission path The second ground pattern 22 and the ground pattern 32 of the upper microwave transmission path 3 are connected via the ground pattern 42 of the vertical microwave transmission path 4 and the through hole 23 of the lower microwave transmission path 2.

  The lower microwave transmission path 2, the upper microwave transmission path 3, and the vertical microwave transmission path 4 are manufactured by being integrally molded. That is, the vertical microwave transmission path 4 is formed on the lower microwave transmission path 2 between the stepped portion 11 of the conductor base 1 and the through hole 23 by using a multilayer technique on the upper base surface 13 of the conductor base 1. Laminated to be high. Then, on the surface of the vertical microwave transmission line 4, a coplanar line 41 that electrically connects the microstrip line 21 of the lower microwave transmission line 2 and the microstrip line 31 of the upper microwave transmission line 3 is formed. A plurality of ground patterns 42 that electrically connect the ground pattern 22 of the lower microwave transmission path 2 and the ground pattern 32 of the upper microwave transmission path 3 are formed. Further, the upper microwave transmission path 3 is connected so as to be in contact with the stacked vertical microwave transmission path 4 and the upper base surface 13 of the conductor base 1.

  In the example of FIG. 2, a microstrip line 21 is formed in the lower microwave transmission path 2, a microstrip line 31 is formed in the upper microwave transmission path 3, and a coplanar line is formed in the vertical microwave transmission path 4. 41 is formed, but other microwave transmission lines may be formed. As shown in FIG. 2, in this substrate connection structure, a part of the lower microwave transmission path 2 and a part of the upper microwave transmission path 3 protrude from the vertical microwave transmission path 4 in different directions. It has a structure that is.

  In this way, the lower microwave transmission path 2, the upper microwave transmission path 3, and the vertical microwave transmission path 4 are integrally formed and manufactured, and a part of the lower microwave transmission path 2 and the upper microwave transmission path are manufactured. 1 has a structure in which a part of 3 protrudes from the vertical microwave transmission path 4 and extends, whereby the ground path 100 is formed along the ground pattern 32 formed on the back surface of the upper microwave transmission path 3 in FIG. As shown, the standing wave ratio can be prevented from deteriorating and the generation of unnecessary radiation, and the number of components can be reduced and the size can be reduced, and the machining process can also be reduced. The ground path 100 at this time does not depend on the shape of the conductor base 1 having the step portion 11 in the height direction as shown in FIG. 1, and is along the ground pattern 32 of the upper microwave transmission path 3.

  As described above, according to the first embodiment, when connecting microwave transmission lines installed at different heights, the lower microwave transmission line 2, the upper microwave transmission line 3, and the vertical microwaves are connected. The wave transmission path 4 is integrally molded, and a part of the lower microwave transmission path 2 and a part of the upper microwave transmission path 3 protrude from the vertical microwave transmission path 4 in different directions. By adopting the structure, it is possible to suppress the deterioration of the standing wave ratio and the generation of unnecessary radiation, reduce the number of parts, make it compact, and reduce the machining process. Is obtained.

Embodiment 2. FIG.
FIG. 3 shows a microwave circuit according to the second embodiment of the present invention and shows a substrate connection structure. In this substrate connection structure, the vertical microwave transmission path 4 shown in FIG. 2 of the first embodiment is a dielectric having a dielectric constant set to an appropriate value so as to realize a wavelength within the use band with less reflection. The other configuration is the same as that of FIG. 2. In this way, by setting the dielectric constant of the dielectric used in the vertical microwave transmission path 4A to an appropriate value, it is possible to arbitrarily set the wavelength within the use band with less reflection.

The cause of the deterioration of the standing wave ratio is a reflected wave in the horizontal-vertical conversion unit 51 and the vertical-horizontal conversion unit 52 shown in FIG. Assuming that the reflection phase in the horizontal-vertical conversion unit 51 is φHV, the reflection phase in the vertical / horizontal conversion unit 52 is φVH, the height of the vertical microwave transmission path 4A is H, and the wavelength in the use band with less reflection is λ, the wavelength λ Is obtained by the following equation.
λ = 4 · H / {(2n + 1) − (φHV + φVH) / π}
Here, n is an arbitrary natural number.
Then, by using a dielectric having a dielectric constant that realizes the obtained wavelength λ for the vertical microwave transmission path 4A, a good standing wave ratio can be realized with respect to a step having an arbitrary height.

  Further, since the dielectric constant is determined by the material property value of the dielectric, the dielectric used for the vertical microwave transmission path 4A has a multi-layer structure, and each dielectric has a different dielectric constant, An appropriate wavelength λ within the use band may be realized by appropriately setting the thickness of the light, and in this case, an arbitrary wavelength within the use band with less reflection can be easily set.

  As described above, according to the second embodiment, the dielectric constant of the dielectric used for the vertical microwave transmission path 4A is set to an appropriate value, that is, depending on the height of the vertical microwave transmission path 4A. By using a dielectric having a dielectric constant that realizes a wavelength within the use band with less reflection to be determined in the vertical microwave transmission path 4A, reflected waves at the horizontal-vertical conversion unit 51 and the vertical-horizontal conversion unit 52 are reflected. Can be canceled within the use band, and an effect that a good standing wave ratio can be realized is obtained. In many cases, the length in the height direction is determined by the shape constraints of the equipment, and it is difficult to adjust arbitrarily. However, there is a limitation by setting the dielectric constant of the dielectric to an appropriate value. Without changing the height of the lower microwave transmission path 2 and the upper microwave transmission path 3, it is possible to set the wavelength within the use band with less reflection.

  Further, according to the second embodiment, the dielectric used for the vertical microwave transmission line 4A has a multi-layer structure, and within the use band where the reflection is small depending on the dielectric constant of the dielectric of each layer or the thickness of the dielectric of each layer. By realizing this wavelength, it is possible to easily set an arbitrary wavelength within the use band with less reflection.

Embodiment 3 FIG.
FIG. 4 shows a microwave circuit according to Embodiment 3 of the present invention, and shows a substrate connection structure. In this substrate connection structure, the vertical microwave transmission path 4 shown in FIG. 2 of the first embodiment is configured by a multilayer substrate in which a microwave circuit 44 as an additional function of a coupler, a filter, an impedance converter, etc. is built in an inner layer. The other vertical configuration is the same as that of FIG. 2. In FIG. 4, the microwave circuit 44 is connected to the signal line 25 of the lower microwave transmission path 2 and the signal line 35 of the upper microwave transmission path 3 through a signal line 45. As described above, by incorporating the microwave circuit 44 in the inner layer of the vertical microwave transmission path 4B, the microwave circuit 44 that has conventionally been installed in the plane portion can be integrated with the vertical microwave transmission path 4B. Further downsizing can be realized

  In addition, in the vertical microwave transmission path 4B formed of a multilayer substrate, the dielectric layer 46 in the portion of the microwave circuit 44 is locally a dielectric having a high dielectric constant, thereby reducing the size of the microwave circuit 44. It can be made smaller, and further downsizing can be realized. Further, by using a dielectric having a high dielectric constant locally, a low loss can be realized as compared with the case where the whole is generally filled with a high dielectric constant material having a large loss. Alternatively, the dielectric layer 46 in the microwave circuit 44 may have a multilayer structure, and the dielectric constant of each layer may be set to a different value.

  As described above, according to the third embodiment, by incorporating the microwave circuit 44 in the inner layer of the vertical microwave transmission path 4B, the microwave circuit 44 that has conventionally been installed in the plane portion can be converted into the vertical microwave. It is possible to integrate with the transmission line 4B and to obtain an effect that further downsizing can be realized.

  Further, according to the third embodiment, the dielectric used for the vertical microwave transmission line 4B has a multilayer structure, and a dielectric having a high dielectric constant is locally used as the dielectric of the microwave circuit 44. As a result, the size of the microwave circuit 44 can be reduced, further miniaturization can be realized, and lower loss can be realized as compared with the case where the whole is filled with a high dielectric constant material.

It is a figure explaining the connection structure of the board | substrate by Embodiment 1 of this invention. It is a figure which shows the connection structure of the board | substrate by Embodiment 1 of this invention. It is a figure which shows the connection structure of the board | substrate by Embodiment 2 of this invention. It is a figure which shows the connection structure of the board | substrate by Embodiment 3 of this invention. It is a figure explaining the connection structure of the conventional board | substrate.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 Conductor base, 2 Lower microwave transmission path, 3 Upper microwave transmission path, 4, 4A, 4B Vertical microwave transmission path, 11 Step part, 12 Lower base surface, 13 Upper base surface, 21 Microstrip Line, 22 Ground Pattern, 23 Through Hole, 25 Signal Line, 31 Microstrip Line, 32 Ground Pattern, 35 Signal Line, 41 Coplanar Line, 42 Ground Pattern, 44 Microwave Circuit, 45 Signal Line, 46 Dielectric Layer, 51 Horizontal -Vertical conversion part, 52 Vertical-horizontal conversion part, 62 Microwave transmission path, 63 Upper microwave transmission path, 64 Upper board, 65 Connection member, 100 Ground path.

Claims (5)

A lower microwave transmission line;
An upper microwave transmission line having a different height from the lower microwave transmission line; and
A vertical microwave transmission path coupled to the lower microwave transmission path and the upper microwave transmission path by integral molding;
A substrate connection structure, wherein a part of the lower microwave transmission line and a part of the upper microwave transmission line extend from the vertical microwave transmission line.   2. The substrate according to claim 1, wherein a dielectric having a dielectric constant that realizes a wavelength within a use band with less reflection determined by the height of the vertical microwave transmission line is used for the vertical microwave transmission line. Connection structure.   The dielectric used in the vertical microwave transmission line is formed in a multilayer structure, and a wavelength within a use band with less reflection is realized by a dielectric constant of each layer dielectric or a thickness of each layer dielectric. 2. The board connection structure according to 2.   2. The substrate connection structure according to claim 1, wherein a microwave circuit is built in an inner layer of the vertical microwave transmission path.   5. The substrate connection structure according to claim 4, wherein the dielectric used in the vertical microwave transmission path has a multilayer structure, and a dielectric having a high dielectric constant is locally used as the dielectric of the microwave circuit portion. .

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