JP2001177012A - Wiring board for high frequency - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress an increase in the reflection loss of a high-frequency signal and the like in a high-frequency input/output part formed by connecting the fellow coplanar lines of a conventional wiring board for high frequency with each other. SOLUTION: A wiring board for high-frequency is constituted into a structure that a first coplanar line 5 formed on the upper surface of a dielectric substrate 2 and a second coplanar line 8 formed on the lower surface of the substrate 2 in parallel to the line 5 are arranged in opposition to each other holding an inner layer grounding conductor 9 between them and at the same time, the fellow points of line conductors 3 and 6 are electrically connected with each other through through conductors 10 and is provided with a high-frequency input/output part formed by electrically connecting fellow grounding conductors 4 and 7 with each other through grounding through conductors 11 at the position of 0.2 to 5 mm from the conductors 10 on both sides in the directions intersecting orthogonally both lines 5 and 8. The shift of the phase of the ground is suppressed and an increase in the reflection loss of a high-frequency signal in the high-frequency input/output can be suppressed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-frequency wiring board having a high-frequency input / output section with improved electrical characteristics.

[0002]

2. Description of the Related Art In a high-frequency wiring board used for a high-frequency circuit board, a high-frequency semiconductor element storage package, a high-frequency semiconductor element mounting chip carrier, and the like, a high-frequency semiconductor element or the like mounted on the upper surface thereof is used. High-frequency transmission lines for transmitting high-frequency signals are formed on the upper and lower surfaces to electrically connect the components for high-frequency wiring of the external electric circuit board on which the high-frequency wiring board is mounted. A high-frequency input / output section is formed by electrically connecting them with a through conductor. The high-frequency wiring board is mounted on the external electric circuit board, and the high-frequency transmission line on the lower surface is electrically connected to the connection line conductor of the external electric circuit board, so that the high-frequency wiring board is mounted and used. Will be done.

As an example in which such a conventional high-frequency wiring board is applied to a package for mounting a high-frequency semiconductor device, there is a package described in, for example, Japanese Patent No. 2605502. The package includes a package substrate, a package side wall mounted on the package substrate, a lid for sealing a cavity formed by being surrounded by the package side wall, and a die for mounting a semiconductor integrated circuit chip provided in the cavity. An external coplanar line having a bonding area, an internal high-frequency transmission line made of a metal thin film on the surface of a dielectric substrate provided in the cavity, and a lead terminal formed of the metal thin film on the bottom of the package substrate; In a package consisting of a high-frequency transmission line and a via hole made of metal that electrically connects the external coplanar line, the internal high-frequency transmission line formed in the cavity is constituted by a coplanar line, and the internal high-frequency transmission line and the external A plurality of metal bars are provided between each ground metal of the coplanar line. It is characterized in that it has connected by via hole.

According to this, since the internal high-frequency transmission line is configured as a coplanar line, the line width of the signal line can be reduced by appropriately selecting the distance between the signal line and the ground metal. The line width can be adjusted to a lower value, the loss can be reduced, and the reflection loss can be reduced.

Further, when the external coplanar line and the internal high-frequency transmission line are connected by a plurality of via holes or via holes having a coaxial structure, high-frequency mismatch is small, and
In addition, it is possible to increase the isolation.

The reason why the coplanar line is used as the high-frequency transmission line is that the pattern width of the signal line on the side (upper surface) on which the high-frequency component is mounted on the high-frequency wiring board and the external electric circuit substrate on the lower surface are used. For the purpose of compensating for the discontinuity with the pattern width of the signal line on the side (lower surface) mounted on the substrate and improving the isolation between the signal lines, it is preferable to connect the coplanar lines as compared with the microstrip line. It is because of that.

[0007]

However, in the high-frequency wiring board applied to the package described in Japanese Patent No. 2605502, a connection between a coplanar line as an internal high-frequency transmission line and a via hole as a through conductor. Between the ground phase at the portion and the ground phase at the connection between the external coplanar line and the via hole, the ground on the front and back surfaces is conducted through the via hole,
The shift occurred due to the long ground path.
Therefore, there is a problem in that reflection of a transmitted high-frequency signal occurs at a connection portion between the internal coplanar line and the external coplanar line, and the reflection loss increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object to eliminate a phase shift of the ground at the connection between the coplanar line and the through conductor, and to reduce the reflection loss of a high-frequency signal. It is an object of the present invention to provide a high-frequency wiring board provided with a high-frequency input / output unit capable of suppressing the occurrence of the high-frequency wiring.

[0009]

A high-frequency wiring board according to the present invention comprises a first coplanar line formed on an upper surface of a dielectric substrate for transmitting a high-frequency signal, and a first coplanar line formed on a lower surface of the dielectric substrate. The first coplanar line and a second coplanar line formed in parallel with each other are disposed to face each other with an inner layer ground conductor formed inside the dielectric substrate interposed therebetween. The ground conductors of the two coplanar lines are electrically connected to each other by a through conductor insulated from the inner layer ground conductor, and at a distance of 0.2 to 5 mm from both sides of the through conductor in a direction orthogonal to the two coplanar lines. And a high-frequency input / output unit electrically connected to the inner layer ground conductor by a ground through conductor electrically connected to the inner layer ground conductor.

According to the high-frequency wiring board of the present invention, the structure of the high-frequency input / output unit is such that the first and second coplanar lines are arranged opposite to each other with the inner-layer ground conductor formed in the dielectric substrate interposed therebetween. The ground conductors of the two coplanar lines are electrically connected to each other through the ground through conductor electrically connected to the inner-layer ground conductor at the predetermined position from the through conductor that electrically connects the ends of the line conductors of the line. Since the connection part is formed by the through conductor, the inner-layer ground conductor, and the ground through conductor, the ground conductor is arranged around the through conductor to perform impedance matching, and therefore has electrical characteristics close to a coaxial structure. And the high-frequency mismatch can be reduced to reduce the reflection loss. In addition, since an inner-layer ground conductor is formed between the coplanar lines, and the inner-layer ground conductor and the ground conductors of both coplanar lines are electrically connected by the ground through conductor, the ground conductor is in the same plane. Since the phase difference of the ground due to the length of the signal line due to the length of the via hole is eliminated, the phase of the ground at the connection portion between the line conductor and the through conductor can be equalized and the shift can be eliminated. The reflection loss can be suppressed by suppressing the occurrence of signal reflection.

Further, according to the high-frequency wiring board of the present invention, when the lead terminal is attached to the line conductor of the second coplanar line, the pattern width of the line conductor is required to increase the attachment strength of the lead terminal. And the width of the lead terminal are related to each other, the impedance of the second coplanar line and the inner-layer ground conductor are separated to perform impedance matching, so that the line width of the line conductor can be increased. The wearing strength can be increased.

Further, in the high-frequency wiring board according to the present invention, the ground conductor of the first and second coplanar lines extends so as to surround a tip of each of the line conductors. At a position of 0.2 to 5 mm from the through conductor in the extension direction of the transmission direction at the tip of the conductor, the inner-layer ground conductor and the extended ground conductor are electrically connected by auxiliary ground through conductors, respectively. It is a feature.

As described above, the ground conductor extends in the direction of extension of the transmission direction at the tip of the line conductor, and the ground conductor and the inner-layer ground conductor extending at a predetermined position in the direction are electrically connected by the auxiliary ground through conductor. In the case of connection, since the ground conductor wall is formed by providing the ground through conductor in the signal transmission direction, the high-frequency wave from the tip of the line conductor into the dielectric substrate extending in the transmission direction extension direction. Leakage of the electromagnetic field of the signal can be effectively suppressed, and reflection loss of the high-frequency signal at the high-frequency input / output unit can be further suppressed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a high-frequency wiring board according to the present invention will be described with reference to the drawings.

FIGS. 1A and 1B show an embodiment of a high-frequency wiring board according to the present invention. FIG. 1A is a top view, FIG. 1B is a cross-sectional view taken along the line AA ′ of FIG. (c) is a sectional view taken along the line BB 'of (a), and (d) is a bottom view. Each shows the vicinity of the high frequency input / output unit.

In these figures, reference numeral 1 denotes a high-frequency wiring board. Reference numeral 2 denotes a dielectric substrate, 3 denotes a first line conductor formed on the upper surface of the dielectric substrate 2 for transmitting a high-frequency signal, and 4 denotes a first ground disposed on both sides of the first line conductor 3. Conductor, and the line conductor 3 and the ground conductor 4
The coplanar line 5 of FIG. Reference numeral 6 denotes a second line conductor formed on the lower surface of the dielectric substrate 2 in parallel with the first line conductor 3 so that the front end thereof faces the first line conductor 3, and 7 denotes a second line conductor 6. , And a second coplanar line 8 is formed by the line conductor 6 and the ground conductor 7. In this example,
Two first and second coplanar lines 5 and 8 are formed respectively.

Reference numeral 9 denotes an inner-layer ground conductor formed inside the dielectric substrate 2 so as to face the first coplanar line 5 and the second coplanar line 8, and 10 denotes a line conductor of the first coplanar line 5. 3 is a through conductor that electrically connects the tip of the line conductor 6 of the second coplanar line 8 to the tip of the line conductor 6, and the through conductor 10 is electrically insulated from the inner-layer ground conductor 9.

The first coplanar line 5 formed on the upper surface of the dielectric substrate 2 and the second coplanar line 8 formed on the lower surface of the dielectric substrate 2 Opposingly disposed with the inner-layer ground conductor 9 formed therein interposed therebetween, the line conductors 3 of both coplanar lines 5.8 are provided.
The six tips are electrically connected to each other by the through conductor 10 to constitute a high-frequency input / output unit of the high-frequency wiring board 1. In such a high-frequency input / output unit, the line conductor 7 of the second coplanar line 8 also serves as a mounting electrode for connection to an external electric circuit board.

Reference numeral 11 denotes a ground through conductor which is electrically connected to the inner layer ground conductor 9 and
The ground conductors 4.7 of the first and second coplanar lines 5.8 are electrically connected to each other at a position of 0.2 to 5 mm on both sides in a direction orthogonal to the first and second coplanar lines 5.8 from 0. Is to be connected to.

In this example, the first ground conductor 4 formed on the upper surface of the dielectric substrate 2 and the second ground conductor 7 formed on the lower surface surround the ends of the respective line conductors 3 and 6. , So that a better grounding state can be obtained.

Reference numeral 12 denotes a frame joined to the upper surface of the dielectric substrate 2, and M denotes a mounting portion for electronic components such as semiconductor elements formed on the upper surface of the dielectric substrate 2. By providing the mounting portion M and the frame 12 in this manner, the high-frequency wiring board 1 can be used as an electronic component storage package for storing high-frequency electronic components. Such a high-frequency wiring board 1 can be manufactured by, for example, a ceramic green sheet laminating method or the like. In this case, the dielectric substrate 2 is formed by laminating a plurality of dielectric layers 2a and 2b. At this time, by setting the dielectric layers 2a and 2b to an appropriate thickness, the position of the inner-layer ground conductor 9, that is, the distance between the inner-layer ground conductor 9 and the first and second coplanar lines 5.8 can be changed. The desired setting can be made according to the required specification for.

In particular, the position where the inner-layer ground conductor 9 is formed is
When the distance from the first coplanar line 5 is set to be smaller than the distance from the second coplanar line 8, impedance matching can be performed, and the pattern width of the second coplanar line can be increased. This is preferable because the attachment strength of the terminal is increased.

According to such a high frequency wiring board 1 of the present invention, the first and second
The connection between the coplanar lines 5 and 8 can be made to have electrical characteristics close to a coaxial structure by the through conductor 10, the inner-layer ground conductor 9, and the ground through conductor 11, thereby reducing high-frequency mismatch. The reflection loss can be reduced, the phase of the ground at the connection between the line conductors 3 and 6 and the through conductor 10 can be made equal to eliminate the shift, and the occurrence of reflection of high-frequency signals can be suppressed. The reflection loss can be suppressed.

Here, the position where the ground through conductor 11 is formed is defined by the first and second coplanar lines 5 extending from the through conductor 10.
When the position is closer than 0.2 mm on both sides in the direction orthogonal to 8, a capacitive component due to electromagnetic coupling between the through conductor 10 and the ground through conductor 11 and an inductive component (self-induction component)
Among them, the capacitive component increases. Then, the matching between the capacitive component and the inductive component suitable for impedance matching is impaired, and a resonance point tends to appear, and the manufacturing tends to be difficult. On the other hand, when the position where the ground through conductor 11 is formed is located at a distance farther than 5 mm, the capacitive component decreases and the inductive component relatively increases, so that a resonance point tends to appear. Therefore, the position where the ground through conductor 11 is formed is 0.2 to 5 mm on both sides in the direction orthogonal to the first and second coplanar lines 5.8.
Is required.

The high-frequency wiring board 1 of the present invention is mounted on the upper surface of an external electric circuit board.
The line conductor 6 of the second coplanar line 8 is connected to the line conductor for connection of the external electric circuit board, and the ground conductor 7 is connected to the ground conductor of the external electric circuit board by a conductive connecting member such as a solder bump or a solder material. By electrically connecting by the used reflow process, the high-frequency wiring board 1 is mounted on the external electric circuit board.

Next, another embodiment of the high-frequency wiring board according to the present invention is shown in FIG. 2 in the same view as FIG. In FIG. 2, (a) is a top view, and (b) is A-
A ′ line sectional view, (c) is a BB ′ line sectional view of (a),
(D) is a bottom view, all showing the vicinity of the high frequency input / output unit. The same parts as those in FIG. 1 are denoted by the same reference numerals.

In these figures, 1 is a high-frequency wiring board, 2 is a dielectric board formed by laminating a plurality of dielectric layers 2a and 2b, and 3 is a first dielectric board formed on the upper surface of the dielectric board 2. Are the first ground conductors disposed on both sides of the first line conductor 3, and 5 are the first line conductors 3 and the ground conductors 4.
And a first coplanar line composed of: Reference numeral 6 denotes a second substrate formed on the lower surface of the dielectric substrate 2 in parallel with the first line conductor 3 so that the front end thereof faces the first line conductor 3.
Is a second ground conductor disposed on both sides of the second line conductor 6, and 8 is a second coplanar line constituted by the line conductor 6 and the ground conductor 7. In this example, as in the example of FIG.
8 are formed two each.

Reference numeral 9 denotes a first and a second inside the dielectric substrate 2.
The inner-layer ground conductor 10 formed so as to face the coplanar lines 5 and 8 electrically connects the tip of the line conductor 3 of the first coplanar line 5 and the tip of the line conductor 6 of the second coplanar line 8. It is a through conductor to be connected. Reference numeral 11 denotes a ground through conductor, which is electrically connected to the inner-layer ground conductor 9, and is 0.2 to 5 mm on both sides in a direction orthogonal to the first and second coplanar lines 5.8 from the through conductor 10.
, The first and second coplanar lines 5.
8 ground conductors 4 and 7 are electrically connected to each other.

Reference numeral 12 denotes a frame joined to the upper surface of the dielectric substrate 2, and M denotes a mounting portion for electronic components such as semiconductor elements formed on the upper surface of the dielectric substrate 2.

Reference numeral 13 denotes an auxiliary ground through conductor,
The first ground conductor 4 formed on the upper surface of the dielectric substrate 2 and the second ground conductor 7 formed on the lower surface are extended so as to surround the ends of the respective line conductors 3 and 6 so as to improve the performance. A ground state can be obtained, and the line conductor 3 of the first coplanar line 5 and the second coplanar line 8
The inner-layer ground conductor 9 and the extended ground conductors 4 and 7 are respectively connected to the auxiliary ground through conductor 13 at a position of 0.2 to 5 mm from the through conductor 10 in the extension direction of the transmission direction at the end of each of the line conductors 6. Is electrically connected.

According to such a high-frequency wiring board 1 of the present invention, in the high-frequency input / output section, the connection between the first and second coplanar lines 5.8 is connected to the through conductor 10 as in the example of FIG. And the inner-layer ground conductor 9 and the ground through conductor 11 can have electrical characteristics close to a coaxial structure, can reduce high-frequency mismatch and reduce reflection loss, and It is possible to equalize the phases of the grounds at the connection portions of the through conductors 3 and 6 to eliminate the shift, to suppress the occurrence of reflection of the high-frequency signal, and to suppress the reflection loss. By providing the auxiliary ground through conductor 13 at a predetermined position, the leakage of the electromagnetic field of the high-frequency signal from the tip of the line conductor into the dielectric substrate extending in the transmission direction can be effectively prevented as described above. Thus, the reflection loss of the high-frequency signal in the high-frequency input / output unit can be further suppressed.

Here, when the position where the auxiliary ground through conductor 13 is formed is located at a distance closer than 0.2 mm from the through conductor 10 in the extension direction of each line conductor 3, 6, the through conductor 10
The capacitive component due to the electromagnetic coupling between the conductor and the auxiliary ground through conductor 13 and the capacitive component among the inductive components (self-induced components) increase. Then, the matching between the capacitive component and the inductive component suitable for impedance matching tends to be impaired, and a resonance point tends to appear. On the other hand, when the position where the ground through conductor 13 is formed is located at a distance farther than 5 mm, the capacitive component decreases and the inductive component relatively increases, so that a resonance point tends to appear similarly. . Therefore, the auxiliary ground through conductor 1
3 is formed at a position 0.2 to 5 mm from the penetrating conductor 10 in the extension direction of the transmission direction of each end of the line conductor 3 of the first coplanar line 5 and the line conductor 6 of the second coplanar line 8. It is necessary to

When the ground conductor 4 of the first coplanar line 5 and the ground conductor 7 of the second coplanar line 8 are extended so as to surround the ends of the line conductors 3 and 6, respectively, the first coplanar line 5 Then, the capacitance components are adjusted so as to minimize the loss when transmitting signals to the second coplanar line 8 via the through conductor 10 and vice versa, and the ground conductors 4 and 7 are formed. At this time, it is preferable that the resistance, the inductor, and the capacitance are formed at matching positions in the entire signal line.

The high-frequency wiring board 1 of the present invention is also mounted on the upper surface of the external electric circuit board and the line conductor 7 of the second coplanar line 8 is mounted.
Is electrically connected to the connection line conductor of the external electric circuit board, and the ground conductor 7 is electrically connected to the ground conductor of the external electric circuit board by a conductive connection member such as a solder bump or a reflow process using a solder material. By
The high-frequency wiring board 1 is mounted on the external electric circuit board.

Further, another embodiment of the present invention is shown in FIG. 3 in a view similar to FIG. 3, (a) is a top view, (b) is a sectional view taken along line AA 'of (a), (c) is a sectional view taken along line BB' of (a), and (d) is a bottom view, respectively. Each of them shows the vicinity of the high frequency input / output unit. FIG.
The same reference numerals are given to the same portions as and the detailed description thereof will be omitted.

In the embodiment shown in FIG.
The dielectric substrate 2 comprises three dielectric layers 2a, 2b, 2c, and thus has inner-layer ground conductors 9a, 9b. The inner-layer ground conductor 9a and the inner-layer ground conductor 9b are connected by an intermediate ground through conductor 14. With such a configuration, the wall of the ground potential around the through conductor 10 can be firmly formed, and by adopting a pseudo-coaxial structure close to a coaxial structure, transmission characteristics of a high-frequency signal are improved, and transmission loss is reduced. Can be smaller.

In this configuration, the position where the inner-layer ground conductor 9a is formed is set so that the distance between the first coplanar line 5 and the inner coplanar line 5 is smaller than the distance between the inner-layer ground conductor 9b and the second coplanar line 8. , Impedance matching becomes easier, and the second coplanar line 8
Is preferable because the pattern width can be increased, and the attachment strength of the lead terminal increases.

The length of the intermediate ground through conductor 14 is 50.
It is preferable that the thickness be set to μm to 0.5 mm. If it is less than 50 μm, it is too short to make it difficult to manufacture, and if it exceeds 0.5 mm, the distance between the inner-layer ground conductors 9a and 9b becomes long, so that the ground potential tends to be unstable. .

The length of the ground through conductor 11 connecting the first ground conductor 4 to the upper inner layer ground conductor 9a is 5
If the thickness is less than 50 μm, a capacitance component is generated between the line conductor 3 and the inner-layer ground conductor 9 a due to the proximity thereof, and the impedance of the high-frequency wiring board 1 is reduced for impedance matching. The width of the wiring pattern is reduced. Then, the deterioration of the signal reflection characteristic at the connection between the mounted semiconductor chip and the high-frequency wiring board 1 is increased. If it exceeds 0.5 mm, the wiring pattern width of the high-frequency wiring board 1 tends to be widened, so that the high-frequency wiring board 1 becomes large and hinders miniaturization.

The length of the ground through conductor 11 for connecting the second ground conductor 7 and the lower inner ground conductor 9b is 50 μm or more.
When the thickness is less than 50 μm, the width of the wiring pattern of the high-frequency wiring board 1 is apt to be reduced similarly to the above, so that the strength of the joint portion of the lead terminal for external connection is reduced, or Bonding becomes difficult.
On the other hand, if it exceeds 0.5 mm, the wiring pattern width of the high-frequency wiring board 1 tends to be widened, and therefore the high-frequency wiring board 1 becomes large.

FIG. 4 shows another embodiment of the present invention, in which the auxiliary ground through conductor 13 shown in FIG. 2 is provided in the configuration of FIG. 4, (a) is a top view, (b) is a sectional view taken along line AA 'of (a), (c) is a sectional view taken along line BB' of (a), and (d) is a bottom view, respectively. Each of them shows the vicinity of the high frequency input / output unit. In addition, the same portions as those in FIG. 3 are denoted by the same reference numerals, and detailed description thereof will be omitted. With this configuration,
By adopting a pseudo-coaxial structure close to the coaxial structure, it is possible to improve the transmission characteristics of high-frequency signals and also to prevent the leakage of the electromagnetic field of high-frequency signals from the tip of the line conductor into the dielectric substrate extending in the transmission direction. And the reflection loss of the high-frequency signal in the high-frequency input / output unit can be suppressed. The length of the auxiliary ground through conductor 13 is shown in FIG.
The same range is preferable for the same reason as in the case of the ground through conductor 11 described above.

The high-frequency band referred to in the present invention is 1 to 1
The high frequency wiring board 1 of the present invention is used in a high frequency band of about 1 to 100 GHz and a millimeter wave band, but has a relatively high frequency band of about 1 to 80 GHz. It is preferably used in a low band. This is because in a high-frequency band exceeding 80 GHz, a high-frequency signal is easily affected by an external magnetic field, resulting in an increase in noise and loss. More preferably, it is good to use at about 1 to 40 GHz.

It should be noted that the present invention is not limited to the above-described embodiments, and that various changes and improvements can be made without departing from the scope of the present invention. For example, in the example of the above-described embodiment, the case where two line conductors are provided as the first and second coplanar lines, respectively, is shown. However, a case where one line conductor is provided or a plurality of line conductors are provided. It may be the case of a port. As the inner-layer ground conductors 9a and 9b, two layers are shown in the above embodiment, but three or more layers may be provided.

Further, a plurality of ground through conductors may be provided near the ground through conductor at a repetition interval of about 以下 or less of the wavelength of the high frequency signal.
Still further, a plurality of auxiliary ground through conductors may be provided near the auxiliary ground through conductor at a repetition interval of about 以下 or less of the wavelength of the high-frequency signal.

Further, a structure in which a connecting metal member such as a lead terminal or a ball is attached to the line conductor of the coplanar line may be adopted.

[0046]

According to the high-frequency wiring board of the present invention, the first and second coplanar lines are opposed to each other with the inner-layer ground conductor formed in the dielectric substrate interposed therebetween. A high-frequency input / output section formed by electrically connecting the ground conductors of both coplanar lines via a ground through conductor electrically connected to the inner-layer ground conductor at the predetermined position from a through conductor electrically connected to each other; The connection portion can have electrical characteristics close to a coaxial structure by the through conductor, the inner-layer ground conductor, and the ground through conductor, thereby reducing high-frequency mismatch and reflecting light. Loss can be reduced. Also, since an inner-layer ground conductor is formed between the coplanar lines, and the inner-layer ground conductor and the ground conductors of both coplanar lines are electrically connected by the ground through conductor, the ground at the connection between the line conductor and the through conductor is formed. Can be made equal to eliminate the shift, and the occurrence of reflection of the high-frequency signal can be suppressed to suppress the reflection loss.

According to the high-frequency wiring board of the present invention, the ground conductor extends in the direction of extension of the transmission direction at the end of the line conductor, and the ground conductor and the inner-layer ground conductor extending at predetermined positions in that direction. Is electrically connected to the auxiliary ground through conductor, the leakage of the electromagnetic field of the high-frequency signal from the tip of the line conductor into the dielectric substrate extending in the transmission direction can be effectively suppressed, The reflection loss of the high-frequency signal in the high-frequency input / output unit can be further suppressed.

As described above, according to the present invention, the high-frequency input / output unit having the high-frequency input / output unit capable of eliminating the phase shift of the ground at the connection between the coplanar line and the through conductor and suppressing the reflection loss of the high-frequency signal. The wiring board for use was able to be provided.

[Brief description of the drawings]

1A is a top view showing an example of an embodiment of a high-frequency wiring board according to the present invention, FIG. 1B is a cross-sectional view taken along line AA ′ of FIG. 1A, and FIG. FIG. 3D is a sectional view taken along the line BB ′, and FIG.

2A is a top view showing another example of the high-frequency wiring board according to the embodiment of the present invention, FIG. 2B is a cross-sectional view taken along the line AA ′ of FIG. 2A, and FIG. ) Is a sectional view taken along line BB ′, and (d) is a bottom view.

3A is a top view showing another embodiment of the high-frequency wiring board according to the present invention, FIG. 3B is a cross-sectional view taken along the line AA ′ of FIG. 3A, and FIG. ) Is a sectional view taken along line BB ′, and (d) is a bottom view.

4A is a top view showing another example of the high-frequency wiring board according to the embodiment of the present invention, FIG. 4B is a cross-sectional view taken along line AA ′ of FIG. 4A, and FIG. ) Is a sectional view taken along line BB ′, and (d) is a bottom view.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 high-frequency wiring board 2 dielectric substrate 3 6 line conductor 4 7 ground conductor 5 first coplanar line 8 second coplanar line 9 , 9a, 9b ... inner layer ground conductor 10 ... through conductor 11 ... ground through conductor 13 ... auxiliary ground through conductor 14 ... middle ground through conductor

Claims (2)

[Claims] 1. A first coplanar line formed on an upper surface of a dielectric substrate for transmitting a high-frequency signal, and a second coplanar line formed on a lower surface of the dielectric substrate in parallel with the first coplanar line. The coplanar line is disposed facing the inner layer ground conductor formed inside the dielectric substrate, and the ends of the line conductors of both coplanar lines are electrically connected to each other by a through conductor insulated from the inner layer ground conductor. A ground through conductor which electrically connects the ground conductors of both coplanar lines to the inner layer ground conductor at a position of 0.2 to 5 mm on both sides in a direction orthogonal to the both coplanar lines from the through conductor. A high-frequency wiring board, comprising: a high-frequency input / output unit electrically connected to the wiring board. 2. The ground conductor of each of the first and second coplanar lines extends so as to surround an end of each of the line conductors, and the penetrating ends of the line conductors extend in an extension direction of the transmission direction. 2. The high-frequency wiring board according to claim 1, wherein the inner-layer ground conductor and the extended ground conductor are electrically connected to each other by an auxiliary ground through conductor at a position of 0.2 to 5 mm from the conductor.