JPH09223906A - Method for connecting microwave and millimeter wave integrated circuit boards - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce the influence of dielectric in inter-board connection and to perform wide band transmission between microwave and millimeter wave integrated circuit boards without being affected by a ground conductor. SOLUTION: In order to perform the wide band transmission between the microwave and millimeter wave integrated circuit boards 1 and 2 for which a board thickness is turned to be less than about 1/4 of a transmission wavelength and a transmission frequency is equal to or less than 300GHz, for the structure of the input or output terminals of the respective boards, microstrip transmission lines 11 and 21 and two ground terminal 12 and 22 on the boards through a via hole are arranged so as to turn the transmission lines 11 and 21 to a center and the microstrip lines 11 and 21 are connected by a signal line 31 whose ground line 32 is at least one wire-strapped coplanar line 3 so as to connect the boards 1 and 2. At the time, signals in a connection line 3 are transmitted as excitation for which an electric field is an even mode to the ground line 32 with the signal line 31 as the center and the wide band transmission is performed without being affected by the ground surface of the boards 1 and 2.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a frequency of 300 GH.
The present invention relates to a connection line between MIC boards and a connection method for connecting between microwave and millimeter wave integrated circuit (hereinafter referred to as "MIC") boards suitably used for microwave and millimeter-wave equipment of z or less. The present invention relates to an inter-substrate connection line and method.

[0002]

2. Description of the Related Art Generally, in a component using an MIC module, a microstrip transmission line is used for transmitting an inter-module signal, and the connection is performed by using a microstrip transmission line.
As shown in FIG. 8, ribbon or wire bonding is used. 8, reference numerals 1 and 2 denote MIC boards, reference numerals 11 and 12 denote signal lines, reference numeral 3 denotes a ribbon or wire bonding connecting the signal lines 11 and 12, and reference numeral 4 denotes GND.
(Ground).

However, as shown in FIG. 8, in the connection method using only bonding, when the frequency of the transmission signal increases, the high-frequency impedance caused by the inductive property of the wire itself cannot be ignored with respect to the transmission line impedance. As a result, there is a problem that it is difficult to transmit a signal in a wide band. In addition, since the positions of the ground conductors between the substrates do not match, the transmission characteristics are deteriorated due to the discontinuity between the substrates.

In order to solve the above-mentioned problems, the following method has been adopted in connection between conventional MIC substrates.

(1) To minimize the dielectric property, a connection using a ribbon is used.

(2) A stub circuit for adjustment is prepared near the connection end.

(3) Minimize the distance between the substrates.

[0008]

However, there are the following problems in the above-mentioned conventional inter-substrate connection of the MIC.

(1) With ribbon connection, especially 30G
Broadband transmission is no longer possible at high frequencies in the millimeter-wave band above Hz.

(2) Although the adjustment by the stub enables transmission at a high frequency to some extent, transmission over a wide band is difficult due to its frequency characteristics, and the characteristics are not constant.

(3) Regarding the distance between the substrates, two MIs
Since the connection between the C substrate and its ground conductor is performed by soldering, it is difficult to accurately and consistently maintain the distance between the substrates. Further, when the MIC is mounted on different subcarriers and the subcarriers are connected to each other, a gap is generated between the subcarriers, and depending on the distance between the gap and the case, the ground at the transmission frequency between the subcarriers may be reduced. The problem that the potentials do not become the same occurs.

Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to reduce the influence of the dielectric property in the connection between the substrates and to be free from the influence of the ground conductor.
An object of the present invention is to provide a connection method between substrates and a structure of a connection line for realizing broadband transmission between microwave and millimeter-wave integrated circuit substrates.

[0013]

In order to achieve the above object, the present invention provides a microstrip transmission line and two ground ends on a substrate via a via hole so as to be centered on the microstrip transmission line. Input or output end, and the substrate thickness is about 1/4 of the transmission wavelength.
Two integrated circuit boards to be described below, and a connection line composed of a coplanar line in which a ground line is connected to the ground end and the ground line is wire-strap connected at a connection portion of the integrated circuit substrate. A microwave / millimeter wave integrated circuit board connecting line is provided.

Further, according to the present invention, in a method of connecting two microwave / millimeter wave integrated circuit boards provided with a microstrip transmission line, a grounding end for grounding via a via hole is provided in the board at a connecting portion of the board. The above microstrip signal lines are symmetrically provided on both sides in the longitudinal direction, the substrate thickness is about ¼ or less of the transmission wavelength, the ground ends are connected to the ground lines of the coplanar line, and the ground lines are connected. There is provided a method for connecting between microwave and millimeter wave integrated circuit boards, characterized in that the wires are connected to each other by a wire strap.

The principle and operation of the present invention will be described below. In the present invention, in order to perform wide band transmission between two microwave millimeter wave integrated circuit boards having a transmission frequency of 300 GHz or less, the substrate thickness of which is about ¼ or less of the transmission wavelength, the input or output end of each board is As shown in FIG. 1, the structure is such that the microstrip transmission lines 11 and 21 and the two ground ends 12 and 22 on the substrate through via holes are the transmission lines 1
1, MIC substrate 1,
2 is connected to the signal line 3 of the coplanar line 3 in which the ground line 32 is connected by at least one wire strap.
1 connects the microstrip transmission lines 11 and 21. A signal in the coplanar (coplanar) connection line 3 is transmitted as an even mode excitation of the electric field to the ground line 32 around the signal line 31, and is not affected by the ground planes of the MIC substrates 1 and 2, and is transmitted over a wide band. Is done.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram of a first embodiment of the present invention.
FIG. 1A is a diagram showing a connection method between ICs, FIG.
FIG. 1B is a view showing a cross section taken along line AA ′ of FIG.
FIG. 1C is a view of the ground line viewed from the back side, and FIG.
FIG. 2 is a view showing a cross section taken along line BB ′ of FIG. Note that, in FIG. 8 referred to in the description of the conventional example, FIG. 1 and the drawings describing the following embodiments, elements having the same or equivalent functions are denoted by common reference numerals.

In FIG. 1, reference numerals 1 and 2 denote two MIC substrates to be connected to each other, and reference numerals 11 and 21 denote signal line lines having the same impedance. Reference numerals 12 and 22 denote ground terminals on the MIC substrates 1 and 2 in which via holes are formed, respectively.

By setting the substrate length to １ ／ or less of the transmission wavelength, the ground terminals 12 and 22 can be regarded as having the same (same potential) as the ground potential.

Reference numeral 3 denotes a connection line having the same impedance in a coplanar configuration. Regarding the signal connection between the MIC substrate 1 and the connection line 3, one side of the signal line 11 and the signal line 31 are connected by crimping or the like. Similarly, for the signal connection between the MIC substrate 2 and the connection line 3, the signal line is connected. 21 and the other side of the signal line 31 are connected by crimping or the like.

The ground connection between the MIC substrate 1 and the connection line 3 is connected to the ground terminal 12 and one side of the ground line 32. Similarly, the ground connection between the MIC substrate 2 and the connection line 3 is connected to the ground terminal. 22 and the other side of the ground line 32 are connected.

That is, the signal on the connection line 3 is transmitted around the signal line 31 to the ground line 32 as excitation in an even mode. This means that the MIC substrate 1,
2 means that it is not affected by the ground plane. Therefore, the loss caused by the discontinuity of the ground plane generated when the MIC substrates 1 and 2 are connected is reduced.

Further, since odd mode excitation may occur due to discontinuity at the connection point, in order to make the ground potential of the ground line 32 the same on both sides, the ground line 32 is connected by the wire strap 33 to reduce the characteristic deterioration. Suppress the odd mode that is the cause. In the present embodiment, the example of the wire strap 33 is shown as the odd mode suppressing circuit. However, the same effect can be obtained even with a structure such as a ribbon or an air bridge. The number is not limited to one, but may be plural.

As described above, FIG. 8 is a diagram showing a conventional MIC connection method. As shown in FIG.
Although the IC substrates 1 and 2 are connected using ribbon bonding or the like, there is a problem in that the impedance in the microwave and millimeter wave bands increases due to the inductive nature, making it difficult to transmit signals.

FIG. 7 shows a comparison of the electromagnetic field analysis results of the reflection loss in the embodiment of the present invention shown in FIG. 1 and the conventional example shown in FIG. 8 in a part of the millimeter wave band.

As shown in FIG. 7, in the embodiment of the present invention, an improvement in the return loss of 10 dB or more over the entire calculated area is recognized as compared with the connection method according to the conventional example (indicated by a dashed line in the figure). The operation and effect of the embodiment of the present invention are apparent.

FIG. 2 is a block diagram of a second embodiment of the present invention.
FIG. 2A is a diagram for explaining a method of connecting ICs, and FIG.
2B is a plan view, FIG. 2B is a view showing a cross section taken along the line AA ′ of FIG. 2A, FIG. 2C is a view of the ground line viewed from the back side,
FIG. 2D is a diagram showing a cross section taken along the line BB ′ of FIG. In the first embodiment shown in FIG. 1, the MIC substrate has a microstrip line as a transmission line. However, in FIG. 2, the transmission line is mainly transmitted by a ground conductor from above. Inverted microstrip line.

By providing a via hole 34 in the connection line 3 at the connection with the substrate, the ground potential can be made the same as that of the MIC substrates 1 and 2. In order to make the ground potential of the ground line 32 the same,
The wire strap 33 is connected.

FIG. 3 is a block diagram showing a third embodiment of the present invention.
FIG. 3A is a diagram for explaining a method of connecting ICs, and FIG.
3B is a plan view, FIG. 3B is a view showing a cross section taken along line AA ′ of FIG. 3A, FIG. 3C is a view of the ground line viewed from the back side,
FIG. 3D is a diagram showing a cross section taken along line BB ′ of FIG. 3C. In the present invention, the MIC substrate 1 is an inverted microstrip line, and the MIC substrate 2 is a microstrip substrate. In the signal transmission from the MIC board 1 to the MIC board 2, it is understood that the ground conductor of the board is different, but the connection of the electric field is smoothed by relaying the connection line 3. A via hole 34 is provided at a connection portion of the ground line 32 on the MIC substrate 1 side.
2 is connected to the ground terminal 22 disposed on the MIC substrate 2, and the ground lines 32 on both sides are connected by a wire strap 33.

FIG. 4 is a block diagram showing a fourth embodiment of the present invention.
FIG. 4 is a diagram for explaining a method of connecting ICs, and FIG.
4B is a plan view, FIG. 4B is a view showing a cross section taken along line AA ′ of FIG. 4A, FIG. 4C is a view of the connection line viewed from the back side,
FIG. 4D is a view showing a cross section taken along line BB ′ of FIG. 4C. In this example, the MIC substrate 1 uses a microstrip as a transmission line, and the MIC substrate 2 has a coplanar (coplanar) transmission line configuration. MIC substrate 1 of ground line 32
The MIC of the ground line 32 is connected to the ground terminal 12
The substrate 2 is connected to a ground pattern sandwiching the signal line 21. It is clear that signal transmission from the MIC board 1 to the MIC board 2 is smoothly performed even with such a configuration. In FIG. 4, when the MIC substrate 1 is an inverted microstrip line, the same effect can be obtained by providing the via hole 34 in the connection line 3 as shown in FIG. 2 or FIG. It is clear that

FIG. 5 is a block diagram showing a fifth embodiment of the present invention.
FIG. 5 is a diagram for explaining a method of connecting ICs, and FIG.
5A is a plan view, and FIG. 5B is a view showing a cross section taken along line AA ′ of FIG. 5A. In this configuration, wire bonding is used for the connection line 3. That is, the signal lines 11, 1
2, a signal line 31 for connecting the two, ground terminals 12 and 22 on the substrate
The wire bonding is used for all of the ground lines 32 connecting the ground lines 32 and the lines 33 connecting the ground lines 32 to each other.

Most of the distribution of the signal currents on the signal lines 11 and 21 and the ground currents on the ground terminals 12 and 22 are concentrated on the lines, and therefore, as shown in FIG. By making the distance of the line sufficiently small, the same effect as the coplanar connection line described above can be obtained. It is needless to say that the same effect can be obtained with any combination of the MIC substrates 1 and 2 described above.

FIG. 6 shows an M according to the sixth embodiment of the present invention.
It is a figure for demonstrating the connection method between ICs, FIG.
6B is a plan view, FIG. 6B is a view showing a cross section taken along line AA ′ of FIG. 6A, FIG. 6C is a view of the ground line viewed from the back side,
FIG. 6D is a view showing a cross section taken along line BB ′ of FIG. 6C.

As shown in FIG. 6, a stub 13 of about の of the transmission wavelength is added to the connection terminal 12 on the MIC board 1 so that the ground terminal 1 can be transmitted at the transmission frequency.
2 and the MIC substrate 1 can be further improved in grounding state. It is clear that the same effect can be obtained even if an adjustment stub is used on the transmission line 11.

[0035]

As described above, according to the present invention,
By using a coplanar grounding line and matching the potential of the grounding line with a wire strap, it is possible to suppress odd modes that cause frequency characteristic degradation and to reduce the discontinuity of the grounding line between connected substrates. There is an effect that high-frequency signals can be transmitted over a wide band so that the characteristics of the MIC module can be exhibited without being affected. In the present invention, the same effect can be obtained even if the odd-mode suppressing circuit has a structure such as a ribbon or an air bridge in addition to the wire strap, and the number thereof may be plural.

Furthermore, in the conventional connection method, a change in the connection distance between the substrates greatly affects the inductivity, whereas according to the present invention, the performance can be stably exhibited as long as the connection line allows. This has the effect of reducing the number of manufacturing steps and costs.

[Brief description of drawings]

1A and 1B are diagrams showing a configuration of connection between MIC boards according to a first embodiment of the present invention, wherein FIG. 1A is a plan view, FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. (C) is a rear view of the connection line, and (D) is a cross-sectional view taken along line BB 'of (C).

FIGS. 2A and 2B are diagrams illustrating a configuration of connection between MIC substrates according to a second embodiment of the present invention, wherein FIG. 2A is a plan view, FIG. 2B is a cross-sectional view taken along line AA ′ of FIG. (C) is a rear view of the connection line, and (D) is a cross-sectional view taken along line BB 'of (C).

3A and 3B are diagrams showing a configuration of connection between MIC substrates according to a third embodiment of the present invention, wherein FIG. 3A is a plan view, FIG. 3B is a cross-sectional view taken along line AA ′ of FIG. (C) is a rear view of the connection line, and (D) is a cross-sectional view taken along line BB 'of (C).

4A and 4B are diagrams showing a configuration of MIC board-to-board connection according to a fourth embodiment of the present invention, in which FIG. 4A is a plan view and FIG. 4B is a cross-sectional view taken along the line AA ′ in FIG. (C) is a rear view of the connection line, and (D) is a cross-sectional view taken along line BB ′ of (C).

FIGS. 5A and 5B are diagrams illustrating a configuration of connection between MIC substrates according to a fifth embodiment of the present invention, wherein FIG. 5A is a plan view and FIG. 5B is a cross-sectional view taken along line AA ′ of FIG. is there.

6A and 6B are diagrams showing a configuration of connection between MIC substrates according to a sixth embodiment of the present invention, wherein FIG. 6A is a plan view, FIG. 6B is a cross-sectional view taken along line AA ′ of FIG. (C) is a rear view of the connection line, and (D) is a cross-sectional view taken along line BB 'of (C).

FIG. 7 is a graph showing calculation results of the reflection loss in the connection between the MIC boards according to the first embodiment of the present invention and the reflection loss due to the conventional connection between the MIC boards as a comparative example.

8A and 8B are diagrams showing a configuration of a conventional connection between MIC substrates, wherein FIG. 8A is a plan view, and FIG. 8B is a cross-sectional view taken along line AA ′ of FIG. 8A.

[Explanation of symbols]

 Reference Signs List 1 MIC board 2 MIC board 3 Coplanar line 4 Ground 11 Signal line 12 Ground terminal on board 13 Adjusting stub 21 Signal line 22 Ground terminal on board 23 Adjusting stub 31 Signal line 32 Ground line 33 Wire strap 34 Via hole

Claims (12)

[Claims] 1. A microstrip transmission line and an input end or an output end arranged so that two ground ends on a substrate via a via hole are centered on the microstrip transmission line, and a substrate thickness is transmitted. Two integrated circuit boards each having a wavelength of about ¼ or less, and a coplanar connection line in which the ground line connected to the ground end is wire-strap connected, are provided. Microwave millimeter-wave integrated circuit board connection line. 2. Two integrated circuit boards having an inverted microstrip transmission line configuration in which the distance to the ground plane is about ¼ or less of the transmission wavelength, and the ground plane is connected to the ground plane at a connection portion of the integrated circuit board. A microwave-millimeter-wave integrated circuit board-to-board connection line, comprising a coplanar connection line in which a ground line having a structure of grounding via a via hole is wire-strap connected. 3. A microstrip transmission line, and an input end or an output end arranged so that two ground ends on a substrate via a via hole are centered on the transmission line.
And the substrate thickness is about 1/4 or less of the transmission wavelength
Integrated circuit board, a second integrated circuit board having an inverted microstrip transmission line configuration in which the distance to the ground plane is about ¼ or less of the transmission wavelength, and the first integrated circuit board side And a ground line having a structure of being grounded via a via hole to the ground plane at the connection part on the side of the second integrated circuit substrate while being connected to the ground end at the connection part of A connecting line between microwave and millimeter-wave integrated circuit boards, comprising: 4. One of the integrated circuit boards is an integrated circuit board having a coplanar transmission line structure, and the ground line is composed of a coplanar line wire-strap connected. The connection line between the microwave and millimeter wave integrated circuit boards according to claim 3. 5. The microwave / millimeter-wave integrated circuit board-to-board connecting line according to claim 1, wherein the coplanar line is formed by wire bonding. 6. An adjusting circuit by a microstrip line having a wavelength of about ¼ of a transmission center frequency is added to the ground terminal of the input terminal or the output terminal of the integrated circuit board. 1. The connection line between the microwave and millimeter wave integrated circuit boards according to 1 or 3. 7. A microwave-millimeter-wave integrated circuit board-to-board connecting line according to any one of claims 1 to 6, wherein the transmission frequency of the board is in a microwave-millimeter-wave band of approximately 300 GHz or less. . 8. A method of connecting two microwave / millimeter wave integrated circuit boards provided with a microstrip transmission line, wherein a grounding end for grounding via a via hole is provided on the board at the connecting portion of the board. Symmetrically provided on both sides in the longitudinal direction of the signal line, the substrate thickness is about ¼ or less of the transmission wavelength, the ground ends are connected to the ground lines of the coplanar line, and the ground lines are wire-strapped to each other. A method for connecting between microwave and millimeter-wave integrated circuit boards, characterized in that the connections are made. 9. A method for connecting between two microwave / millimeter wave integrated circuit boards having an inverted microstrip transmission line structure in which a distance to a ground plane is about ¼ or less of a transmission wavelength, wherein the boards are connected. Microwave millimeter wave characterized in that the substrates are connected by a coplanar line in which ground lines having a structure of grounding to the ground plane via via holes Connection method between integrated circuit boards. 10. A microstrip transmission line and an input end or an output end arranged so that two ground ends on a substrate via a via hole are arranged with the transmission line as a center, and the substrate thickness is a transmission wavelength. 1/4 or less of the first integrated circuit board and a second integrated circuit having an inverted microstrip transmission line configuration in which the distance to the ground plane is 1/4 or less of the transmission wavelength. A circuit board and a connection method between the boards, wherein ground lines are respectively connected to the two ground ends at a connection portion with the first integrated circuit board side, and the ground line is the second line. In the coplanar line having a structure in which the ground plane is grounded via a via hole at a connection portion with the integrated circuit board side, and the ground plane is a wire-strap connection with each other, Microwave and Millimeter-wave integrated circuit board connecting method being characterized in that connected between. 11. The microwave according to claim 8, wherein an adjusting circuit by a microstrip line having a quarter wavelength of a transmission center frequency is added to an input end or an output end of the integrated circuit board. Method for connecting millimeter-wave integrated circuit boards. 12. The microwave millimeter wave according to claim 8, wherein the ground lines are connected to each other by at least one connecting member of a bridge type connecting member of a wire strap, a ribbon and an air bridge. Connection method between integrated circuit boards.